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1. Monitoring of generalised corrosion: Ultrasonic coda wave interferometry technique applied to steel corrosion in aqueous NaCl solutions

Author: Cyril Nicard, Maxime Farin, Emmanuel Moulin, David Balloy, Ingrid Proriol Serre, Unité Matériaux et Transformations - UMR 8207 (UMET), Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-JUNIA (JUNIA), Université catholique de Lille (UCL)-Université catholique de Lille (UCL), Transduction, Propagation et Imagerie Acoustique - IEMN (TPIA - IEMN), INSA Institut National des Sciences Appliquées Hauts-de-France (INSA Hauts-De-France), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Université catholique de Lille (UCL)-Université catholique de Lille (UCL)-Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-JUNIA (JUNIA), SOCORRO, and This study was supported by our institutes and partially by the European Union. This work was a part of the European project Interreg 2 Seas, Seeking Out Corrosion, before it is too late (SOCORRO). This work was supported by Lille University (France) and the French National Center for Scientific Research.
Subjects: [PHYS]Physics [physics], [SPI]Engineering Sciences [physics], Generalised corrosion, Electrochemical experiments, Non-destructive testing, CWI, General Materials Science, Condensed Matter Physics, Sensor
Abstract: International audience; This paper investigates a Non-Destructive Testing based on ultrasonic Coda Wave Interferometry technique to determine if it can be an efficient way to continuously and quantitatively measure the thickness loss due to corrosion on an S355 grade steel in 3 wt% NaCl distilled water. To do so, several electrochemical experiments in open circuit potentials and imposed anodic dissolutions (from few to tens of micrometers) are performed at stable and varying temperatures (20–30 ◦C) in aqueous NaCl. The thickness loss and corrosion rate are continuously measured with CWI thanks to a piezoelectric trasducer and verified post-experiment with an optical depth profile measurement.
Published: 2023
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2. Stable GSTC Formulation for Maxwell’s Equations

Author: Nicolas Lebbe, Kim Pham, Agnes Maurel, Université Côte d'Azur (UCA), Centre National de la Recherche Scientifique (CNRS), Modélisation et méthodes numériques pour le calcul d'interactions onde-matière nanostructurée (ATLANTIS), Inria Sophia Antipolis - Méditerranée (CRISAM), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Alexandre Dieudonné (JAD), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de la mécanique et Applications industrielles (IMSIA - UMR 9219), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-EDF R&D (EDF R&D), EDF (EDF)-EDF (EDF), Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Université Paris sciences et lettres (PSL), Nicolas Lebbe acknowledge support from French defence procurement agency under the ANR ASTRID Maturation program, grant agreement number ANR-18-ASMA-0006-01. Kim Pham acknowledges support from the Agence de l’Innovation de Défense (AID) from the Direction Générale de l’Armement (DGA), under grant n° 2019 65 0070 and the Agence Nationale de la Recherche under grant ANR-19-CE08-0006., ANR-18-ASMA-0006,OPERA,Optique planaire adaptative(2018), ANR-19-CE08-0006,METARESO,Propagation d'ondes dans des Métamatériaux Résonants(2019), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Alexandre Dieudonné (LJAD), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-EDF R&D (EDF R&D), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Asymptotic analysis, Metafilms, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], Metasurface, Numerical implementation of the enlarged GSTCs, Electrical and Electronic Engineering, Generalized sheet transition conditions (GSTC), Two-scale homogenization technique
Abstract: We revisit the classical zero-thickness Generalized Sheet Transition Conditions (GSTCs) which are a key tool for efficiently designing metafilms able to control the flow of light in a desired way. It is shown that it is more convenient to use an enlarged formulation of the GSTC in which the original metafilm is replaced by GSTCs that exclude the layer from the physical or computational domain. These new "layer" transition conditions have the same form as their "sheet" analogues hence they do not necessitate additional complications in their use; their advantage is that they provide a well-posed problem hence guaranty the stability of numerical schemes in the timedomain. These assessments are demonstrated for an all-dielectric structure; the effective susceptibility tensors are derived thanks to asymptotic analysis combined with homogenization technique and bounds for the susceptibilities entering the balance of energy are provided. While negative constant susceptibilities appear in the classical zero-thickness GSTCs, their values in the enlarged formulation are always positive which ensure the stability of the effective problem. Validation of the effective model is provided by means of comparison with direct numerics in two and three dimensions.
Published: 2022
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3. Antenna Radiation Efficiency Estimation From Backscattering Measurement Performed Within Reverberation Chambers

Author: Wafa Krouka, Francois Sarrazin, Julien de Rosny, Adnane Labdouni, Elodie Richalot, Electronique, Systèmes de communication et Microsystèmes (ESYCOM), Conservatoire National des Arts et Métiers [CNAM] (CNAM), HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel, Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Conservatoire National des Arts et Métiers [CNAM] (CNAM)-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)
Subjects: contactless measurement, backscattering measurement, FOS: Physical sciences, quality factor, 020206 networking & telecommunications, Applied Physics (physics.app-ph), Physics - Applied Physics, 02 engineering and technology, Condensed Matter Physics, reverberation chamber, Atomic and Molecular Physics, and Optics, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, Antenna radiation efficiency, 0202 electrical engineering, electronic engineering, information engineering, Electrical and Electronic Engineering
Abstract: This paper presents a contactless measurement method for antenna radiation efficiency estimation within reverberation chambers (RCs). This method does not require to connect any analyzer to the antenna under test (AUT). The AUT radiation efficiency is obtained from the differential measurement of the RC composite $Q$-factor estimated for two AUT load conditions, namely an open circuit and a \SI[detect-weight]{50}{\ohm} load. Remotely-controlled RF switches are used in order to keep the setup identical for both measurements. The method is experimentally validated in two RCs of different volumes (1~m$^3$ and 19~m$^3$) with a wideband patch antenna in the 1.8~GHz to 2.8~GHz frequency range. The estimated efficiency is found to be in very good agreement with the one obtained through a conventional invasive RC measurement technique. This new method is suitable for miniature and buried antenna characterization without access to its port.
Published: 2022
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4. Three-Dimensional Ultrasound Matrix Imaging

Author: Bureau, Flavien, Robin, Justine, Ber, Arthur Le, Lambert, William, Fink, Mathias, Aubry, Alexandre, Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Physique pour la médecine (PhysMed Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Hologic-Supersonic Imagine, Aix-en-Provence, and European Project: 819261,REMINISCENCE
Subjects: [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [INFO.INFO-TI]Computer Science [cs]/Image Processing [eess.IV], Image and Video Processing (eess.IV), FOS: Electrical engineering, electronic engineering, information engineering, [PHYS.PHYS.PHYS-MED-PH]Physics [physics]/Physics [physics]/Medical Physics [physics.med-ph], FOS: Physical sciences, Applied Physics (physics.app-ph), Medical Physics (physics.med-ph), Physics - Applied Physics, Electrical Engineering and Systems Science - Image and Video Processing, Physics - Medical Physics
Abstract: Matrix imaging paves the way towards a next revolution in wave physics. Based on the response matrix recorded between a set of sensors, it enables an optimized compensation of aberration phenomena and multiple scattering events that usually drastically hinder the focusing process in heterogeneous media. Although it gave rise to spectacular results in optical microscopy or seismic imaging, the success of matrix imaging has been so far relatively limited with ultrasonic waves because wave control is generally only performed with a linear array of transducers. In this paper, we extend ultrasound matrix imaging to a 3D geometry. Switching from a 1D to a 2D probe enables a much sharper estimation of the transmission matrix that links each transducer and each medium voxel. Here, we first present an experimental proof of concept on a tissue-mimicking phantom through ex-vivo tissues and then, show the potential of 3D matrix imaging for transcranial applications., 52 pages, 13 figures
Published: 2023

5. Damping-Driven Time Reversal for Waves

Author: Samuel Hidalgo-Caballero, Surabhi Kottigegollahalli Sreenivas, Vincent Bacot, Sander Wildeman, Maxime Harazi, Xiaoping Jia, Arnaud Tourin, Mathias Fink, Alvaro Cassinelli, Matthieu Labousse, Emmanuel Fort, Gulliver (UMR 7083), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut Langevin - Ondes et Images (UMR7587) (IL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Physique et mécanique des milieux hétérogenes (UMR 7636) (PMMH), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), School of Creative Media, City University Hong Kong, City University Hong Kong, AXA Research Fund, Charpak scholarship, CONACYT Mexico, 'Investissements d’Avenir', and European Project: 754387,EU MSCA H2020 COFUND UpToParis
Subjects: [PHYS.PHYS.PHYS-CLASS-PH]Physics [physics]/Physics [physics]/Classical Physics [physics.class-ph], General Physics and Astronomy
Abstract: International audience; Damping is usually associated with irreversibility. Here, we present a counterintuitive concept to achieve time reversal of waves propagating in a lossless medium using a transitory dissipation pulse. Applying a sudden and strong damping in a limited time generates a time-reversed wave. In the limit of a high damping shock, this amounts to "freezing" the initial wave by maintaining the wave amplitude while canceling its time derivative. The initial wave then splits in two counterpropagating waves with half of its amplitude and time evolutions in opposite directions. We implement this damping-based time reversal using phonon waves propagating in a lattice of interacting magnets placed on an air cushion. We show with computer simulations that this concept also applies to broadband time reversal in complex disordered systems.
Published: 2023
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6. Non-invasive Retrieval of the Transmission Matrix for Optical Imaging Deep Inside a Multiple Scattering Medium

Author: Najar, Ulysse, Barolle, Victor, Balondrade, Paul, Fink, Mathias, Boccara, A, Aubry, Alexandre, Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), ANR-10-IDEX-0001,PSL,Paris Sciences et Lettres(2010), European Project: 819261,REMINISCENCE, and European Project: 610110,HELMHOLTZ
Subjects: [PHYS]Physics [physics], FOS: Physical sciences, Physics - Optics, Optics (physics.optics)
Abstract: As light travels through a disordered medium such as biological tissues, it undergoes multiple scattering events. This phenomenon is detrimental to in-depth optical microscopy, as it causes a drastic degradation of contrast, resolution and brightness of the resulting image beyond a few scattering mean free paths. However, the information about the inner reflectivity of the sample is not lost; only scrambled. To recover this information, a matrix approach of optical imaging can be fruitful. Here we report on the compressed measurement of a high-dimension reflection matrix R via low coherence interferometry. Then, we show how the inner transmission matrix linking each camera sensor and each medium voxel can be extracted through an iterative multi-scale analysis of wave distortions contained in R. This transmission matrix is the Holy Grail for volumetric imaging since it enables an optimal compensation of forward multiple scattering paths and provides a three-dimensional confocal image of the sample as the latter one had become digitally transparent. The proof-of-concept experiment is performed on a human opaque cornea and an extension of the penetration depth by a factor five is demonstrated compared to the state-of-the-art., Comment: 39 page, 10 figures
Published: 2023
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7. Seismic surface wave focal spot imaging: numerical resolution experiments

Author: Bruno Giammarinaro, Christina Tsarsitalidou, Gregor Hillers, Julien de Rosny, Léonard Seydoux, Stefan Catheline, Michel Campillo, Philippe Roux, Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut National de la Santé et de la Recherche Médicale (INSERM), Institut des Sciences de la Terre (ISTerre), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel-Université Grenoble Alpes (UGA), ANR-19-P3IA-0003,MIAI,MIAI @ Grenoble Alpes(2019), Institute of Seismology, Department of Geosciences and Geography, and Helsinki Institute of Urban and Regional Studies (Urbaria)
Subjects: 1171 Geosciences, FAULT ZONE, Wave propagation, Seismic noise, RETRIEVAL, Refocusing, Seismic interferometry, Surface waves, 114 Physical sciences, GREENS-FUNCTION, NOISE CORRELATION, WESTERN, Body waves, Geophysics, Geochemistry and Petrology, Numerical modelling, [SDU]Sciences of the Universe [physics], TOMOGRAPHY, CROSS-CORRELATION, Focal spot, ARRAY, Surface waves and free oscillations, PASSIVE ELASTOGRAPHY, CRUSTAL STRUCTURE
Abstract: SUMMARY Numerical experiments of seismic wave propagation in a laterally homogeneous layered medium explore subsurface imaging at subwavelength distances for dense seismic arrays. We choose a time-reversal approach to simulate fundamental mode Rayleigh surface wavefields that are equivalent to the cross-correlation results of three-component ambient seismic field records. We demonstrate that the synthesized 2-D spatial autocorrelation fields in the time domain support local or so-called focal spot imaging. Systematic tests involving clean isotropic surface wavefields but also interfering body wave components and anisotropic incidence assess the accuracy of the phase velocity and dispersion estimates obtained from focal spot properties. The results suggest that data collected within half a wavelength around the origin is usually sufficient to constrain the used Bessel functions models. Generally, the cleaner the surface wavefield the smaller the fitting distances that can be used to accurately estimate the local Rayleigh wave speed. Using models based on isotropic surface wave propagation we find that phase velocity estimates from vertical–radial component data are less biased by P-wave energy compared to estimates obtained from vertical–vertical component data, that even strong anisotropic surface wave incidence yields phase velocity estimates with an accuracy of 1 per cent or better, and that dispersion can be studied in the presence of noise. Estimates using a model to resolve potential medium anisotropy are significantly biased by anisotropic surface wave incidence. The overall accurate results obtained from near-field measurements using isotropic medium assumptions imply that dense array seismic Rayleigh wave focal spot imaging can increase the depth sensitivity compared to ambient noise surface wave tomography. The analogy to elastography focal spot medical imaging implies that a high station density and clean surface wavefields support subwavelength resolution of lateral medium variations.
Published: 2023
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8. Homogenized transition conditions for plasmonic metasurfaces

Author: Nicolas Lebbe, Agnès Maurel, Kim Pham, Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de la mécanique et Applications industrielles (IMSIA - UMR 9219), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-EDF R&D (EDF R&D), EDF (EDF)-EDF (EDF), ANR-10-IDEX-0001,PSL,Paris Sciences et Lettres(2010), ANR-19-CE08-0006,METARESO,Propagation d'ondes dans des Métamatériaux Résonants(2019), and ANR-10-LABX-0024,WIFI,Institut Langevin : Ondes et Images, du Fondamental à l'Innovation(2010)
Subjects: [PHYS]Physics [physics], surface plasmons, metasurfaces, plasmonics
Abstract: International audience; The present study aims to model the optical response of plasmonic metasurfaces made of a periodic arrangement of metallic particles with arbitrary shape and subwavelength dimensions. By combining homogenization with quasistatic plasmonic eigenmode expansion, the metasurface is replaced by a zero-thickness interface associated with frequency-dependent effective susceptibilities. The resulting discontinuities of the fields are responsible for strong interaction with the incoming light at the resonances when the complex permittivity of the metal passes close to the real permittivity of an eigenmode. Our modeling provides a physical picture of resonances in plasmonic metasurfaces, and it allows for a huge decrease in the numerical cost of their computations. In addition, comparisons with direct numerics in two dimensions evidence its predictive force at any incidence, particle shape, and arrangement.
Published: 2023
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9. Imaging the crustal and upper mantle structure of the North Anatolian Fault: A Transmission Matrix Framework for Local Adaptive Focusing

Author: Touma, Rita, Ber, Arthur Le, Campillo, Michel, Aubry, Alexandre, Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de la Terre (ISTerre), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel-Université Grenoble Alpes (UGA), European Project: 819261,REMINISCENCE, and European Project: 742335–F-IMAGE,F-IMAGE
Subjects: Physics - Geophysics, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [SPI]Engineering Sciences [physics], [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, [SDU]Sciences of the Universe [physics], [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, FOS: Physical sciences, Geophysics (physics.geo-ph)
Abstract: Imaging the structure of major fault zones is essential for our understanding of crustal deformations and their implications on seismic hazards. Investigating such complex regions presents several issues, including the variation of seismic velocity due to the diversity of geological units and the cumulative damage caused by earthquakes. Conventional migration techniques are in general strongly sensitive to the available velocity model. Here we apply a passive matrix imaging approach which is robust to the mismatch between this model and the real seismic velocity distribution. This method relies on the cross-correlation of ambient noise recorded by a geophone array. The resulting set of impulse responses form a reflection matrix that contains all the information about the subsoil. In particular, the reflected body waves can be leveraged to: (i) determine the transmission matrix between the Earth's surface and any point in the underground; (ii) build a confocal image of the underground reflectivity with a transverse resolution only limited by diffraction. As a study case, we consider seismic noise (0.1-0.5 Hz) recorded by the Dense Array for Northern Anatolia (DANA) that consists of 73 stations deployed for 18 months in the region of the 1999 Izmit earthquake. Passive matrix imaging reveals the scattering structure of the crust and upper mantle around the NAFZ over a depth range of 60 km. The results show that most of the scattering is associated with the Northern branch that passes throughout the crust and penetrates into the upper mantle., Comment: 37 pages, 8 figures
Published: 2023
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10. Using fluorescent beads to emulate single fluorophores

Author: Luis A. Alemán-Castañeda, Sherry Yi-Ting Feng, Rodrigo Gutiérrez-Cuevas, Isael Herrera, Thomas G. Brown, Sophie Brasselet, Miguel A. Alonso, Institut FRESNEL (FRESNEL), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), University of Rochester [USA], Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Biological Physics (physics.bio-ph), [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, FOS: Physical sciences, Computer Vision and Pattern Recognition, Physics - Biological Physics, Atomic and Molecular Physics, and Optics, Optics (physics.optics), Electronic, Optical and Magnetic Materials, Physics - Optics
Abstract: International audience; We study the conditions under which fluorescent beads can be used to emulate single fluorescent molecules in the calibration of optical microscopes. Although beads are widely used due to their brightness and easy manipulation, there can be notable differences between the point spread functions (PSFs) they produce and those for single-molecule fluorophores, caused by their different emission patterns and sizes. We study theoretically these differences for various scenarios, e.g., with or without polarization channel splitting, to determine the conditions under which the use of beads as a model for single molecules is valid. We also propose methods to model the blurring due to the size difference and compensate for it to produce PSFs that are more similar to those for single molecules.
Published: 2022
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11. Ultrasound Matrix Imaging—Part I: The focused reflection matrix, the F-factor and the role of multiple scattering

Author: William Lambert, Justine Robin, Laura A. Cobus, Mathias Fink, Alexandre Aubry, Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Physique pour la médecine (PhysMed Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), PhD thesis of William Lambert funded by the SuperSonic Imagine company, ANR-10-LABX-0024,WIFI,Institut Langevin : Ondes et Images, du Fondamental à l'Innovation(2010), European Project: 819261,REMINISCENCE, European Project: 744840,SMART, and Physique pour la médecine (UMR 8063, U1273)
Subjects: Ultrasound Matrix Imaging, Transducers, FOS: Physical sciences, Applied Physics (physics.app-ph), FOS: Electrical engineering, electronic engineering, information engineering, Humans, Electrical and Electronic Engineering, Ultrasonography, Coherence Factor, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], Radiological and Ultrasound Technology, Phantoms, Imaging, Image and Video Processing (eess.IV), Physics - Applied Physics, Electrical Engineering and Systems Science - Image and Video Processing, Physics - Medical Physics, Focusing Factor, Computer Science Applications, Multiple scattering, [PHYS.PHYS.PHYS-MED-PH]Physics [physics]/Physics [physics]/Medical Physics [physics.med-ph], Medical Physics (physics.med-ph), Noise, Aberration, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Software, [PHYS.PHYS.PHYS-DATA-AN]Physics [physics]/Physics [physics]/Data Analysis, Statistics and Probability [physics.data-an]
Abstract: This is the first article in a series of two dealing with a matrix approach for aberration quantification and correction in ultrasound imaging. Advanced synthetic beamforming relies on a double focusing operation at transmission and reception on each point of the medium. Ultrasound matrix imaging (UMI) consists in decoupling the location of these transmitted and received focal spots. The response between those virtual transducers form the so-called focused reflection matrix that actually contains much more information than a confocal ultrasound image. In this paper, a time-frequency analysis of this matrix is performed, which highlights the single and multiple scattering contributions as well as the impact of aberrations in the monochromatic and broadband regimes. Interestingly, this analysis enables the measurement of the incoherent input-output point spread function at any pixel of this image. A fitting process enables the quantification of the single scattering, multiple scattering and noise components in the image. From the single scattering contribution, a focusing criterion is defined, and its evolution used to quantify the amount of aberration throughout the ultrasound image. In contrast to the state-of-the-art coherence factor, this new indicator is robust to multiple scattering and electronic noise, thereby providing a contrasted map of the focusing quality at a much better transverse resolution. After a validation of the proof-of-concept based on time-domain simulations, UMI is applied to the in-vivo study of a human calf. Beyond this specific example, UMI opens a new route for speed-of-sound and scattering quantification in ultrasound imaging., 15 pages, 7 figures
Published: 2022
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12. Speckle Decorrelation in Fundamental and Second-Harmonic Light Scattered from Nonlinear Disorder

Author: Rabisankar Samanta, Romain Pierrat, Rémi Carminati, Sushil Mujumdar, Tata Institute for Fundamental Research (TIFR), Institut Langevin - Ondes et Images (UMR7587) (IL), Sorbonne Université (SU)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Paris (UP)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], FOS: Physical sciences, General Physics and Astronomy, Disordered Systems and Neural Networks (cond-mat.dis-nn), Condensed Matter - Disordered Systems and Neural Networks, Physics - Optics, Optics (physics.optics)
Abstract: Speckle patterns generated in a disordered medium carry a lot of information despite the complete randomness in the intensity pattern. When the medium possesses χ (2) nonlinearity, the speckle is sensitive to the phase of the incident fundamental light, as well as the light generated within. Here, we examine the speckle decorrelation in the fundamental and second-harmonic transmitted light as a function of varying power in the fundamental beam. At low powers, the speckle exhibits strong spatial correlations, which decrease with increasing incident power. We measure the statistical distributions of the correlation coefficients, which transform from sharp-peaked distributions at low power, to wide flat distributions at higher power. The average correlation in the second-harmonic speckle decays faster than in the fundamental speckle. Next, we construct a theoretical model, backed up by numerical computations, to obtain deeper physical insights on the faster decorrelations in the second-harmonic light. Whilst providing excellent qualitative agreement with the experiments, the model sheds important light on the contribution of two effects in the correlations, namely, the generation of second-harmonic light, and the propagation thereof.
Published: 2022
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13. Roadmap on wavefront shaping and deep imaging in complex media

Author: Gigan, Sylvain, Katz, Ori, De Aguiar, Hilton B., Andresen, Esben Ravn, Aubry, Alexandre, Bertolotti, Jacopo, Bossy, Emmanuel, Bouchet, Dorian, Brake, Joshua, Brasselet, Sophie, Bromberg, Yaron, Cao, Hui, Chaigne, Thomas, Cheng, Zhongtao, Choi, Wonshik, Čižmár, Tomáš, Cui, Meng, Curtis, Vincent R., Defienne, Hugo, Hofer, Matthias, Horisaki, Ryoichi, Horstmeyer, Roarke, Ji, Na, LaViolette, Aaron K., Mertz, Jerome, Moser, Christophe, Mosk, Allard P., Pégard, Nicolas C., Piestun, Rafael, Popoff, Sebastien, Phillips, David B., Psaltis, Demetri, Rahmani, Babak, Rigneault, Hervé, Rotter, Stefan, Tian, Lei, Vellekoop, Ivo M., Waller, Laura, Wang, Lihong, Weber, Timothy, Xiao, Sheng, Xu, Chris, Yamilov, Alexey, Yang, Changhuei, Yılmaz, Hasan, Afd Nanophotonics, Sub Nanophotonics, Nanophotonics, Laboratoire Kastler Brossel (LKB (Jussieu)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), The Hebrew University of Jerusalem (HUJ), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), School of Physics and Astronomy [Exeter], University of Exeter, Laboratoire Interdisciplinaire de Physique [Saint Martin d’Hères] (LIPhy ), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Harvey Mudd College, Institut FRESNEL (FRESNEL), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Boston University [Boston] (BU), Cornell University [New York], Missouri University of Science and Technology (Missouri S&T), University of Missouri System, Department of Electrical Engineering, California Institute of Technology, Pasadena, CA 91125, USA, Institute of Materials Science and Nanotechnology, National Nanotechnology Research Center (UNAM), Bilkent University, Ankara, 06800, Turkey, Laboratoire Kastler Brossel (LKB (Lhomond)), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Yale University [New Haven], California Institute of Technology (CALTECH), Korea University [Seoul], Leibniz Institute of Photonic Technology (IPHT), Leibniz Association, Institute of Scientific Instruments of the Czech Academy of Sciences, Purdue University [West Lafayette], University of North Carolina [Chapel Hill] (UNC), University of North Carolina System (UNC), SUPA School of Physics and Astronomy [Glasgow], University of Glasgow, The University of Tokyo (UTokyo), Duke University [Durham], University of California [Berkeley] (UC Berkeley), University of California (UC), Department of Biomedical Engineering [Boston], Ecole Polytechnique Fédérale de Lausanne (EPFL), Utrecht University [Utrecht], University of Colorado [Boulder], Vienna University of Technology (TU Wien), Department of Electrical and Computer Engineering [Boston University] (ECE), University of Twente, Department of Electrical Engineering and Computer Sciences (Berkeley EECS), Institute of Material Science and Nanotechnology and National Nanotechnology Research Center [Bilkent university] (UNAM), Bilkent University [Ankara], Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), University of California [Berkeley], University of California, University of Twente [Netherlands], Yılmaz, Hasan, Afd Nanophotonics, Sub Nanophotonics, and Nanophotonics
Subjects: lensless endoscope, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, speckle-correlation, FOS: Physical sciences, real-time, wavefront shaping, Imaging, multimode fibers, adaptive optics, Scattering, Atomic and Molecular Physics, Electronic, Physics - Biological Physics, Optical and Magnetic Materials, mesoscopic physics, Electrical and Electronic Engineering, focusing light, [PHYS]Physics [physics], Microscopy, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], scattering, imaging, phase-conjugation, Multimode fibers, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Biological Physics (physics.bio-ph), thick tissue, Mesoscopic physics, field-of-view, Wavefront shaping, microscopy, learning approach, and Optics, Adaptive optics, scattering media, Optics (physics.optics), Physics - Optics
Abstract: The last decade has seen the development of a wide set of tools, such as wavefront shaping, computational or fundamental methods, that allow to understand and control light propagation in a complex medium, such as biological tissues or multimode fibers. A vibrant and diverse community is now working on this field, that has revolutionized the prospect of diffraction-limited imaging at depth in tissues. This roadmap highlights several key aspects of this fast developing field, and some of the challenges and opportunities ahead., submitted to J.Phys Photonics (IOP), 116 pages, 23 sections
Published: 2022
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14. Statistical Nonlinear Optical Mapping of Localized and Delocalized Plasmonic Modes in Disordered Gold Metasurfaces

Author: Sylvain Gigan, Sébastien Bidault, Samuel Gresillon, Gauthier Roubaud, Institut Langevin - Ondes et Images (UMR7587) (IL), Sorbonne Université (SU)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Paris (UP)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Kastler Brossel (LKB (Lhomond)), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Materials science, business.industry, Physics::Optics, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Nonlinear optical, Delocalized electron, 0103 physical sciences, Optoelectronics, [PHYS.COND.CM-DS-NN]Physics [physics]/Condensed Matter [cond-mat]/Disordered Systems and Neural Networks [cond-mat.dis-nn], Electrical and Electronic Engineering, 010306 general physics, 0210 nano-technology, business, Plasmon, Biotechnology
Abstract: International audience; Using a statistical analysis of nonlinear luminescence images measured with randomly wavefront-shaped femtosecond excitations, we provide direct insight on both the localized and delocalized plasmonic modes featured by disordered gold metasurfaces. We can image independently areas where far-field wavefront shaping can control the optical properties, and areas with strong subwavelength optical hotspots. In practice, the fraction of the disordered plasmonic surface on which wavefront control is feasible depends strongly on the nanoscale morphology of the sample. Close to the percolation threshold, the entire surface is sensitive to wavefront shaping and we observe the largest densities of delocalized modes as well as the strongest optical hotspots. These results demonstrate how statistical imaging schemes can offset the complexity of disordered nanophotonic systems in order to characterize their optical properties.
Published: 2021
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15. Ultrasound Matrix Imaging-Part II: The Distortion Matrix for Aberration Correction Over Multiple Isoplanatic Patches

Author: William Lambert, Laura A. Cobus, Justine Robin, Mathias Fink, Alexandre Aubry, Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Physique pour la médecine (PhysMed Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), PhD thesis of William Lambert funded by the SuperSonic Imagine Company, ANR-10-IDEX-0001,PSL,Paris Sciences et Lettres(2010), European Project: 819261,REMINISCENCE, European Project: 744840,SMART, Sorbonne Université (SU)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Paris (UP)-Centre National de la Recherche Scientifique (CNRS), and Physique pour la médecine (UMR 8063, U1273)
Subjects: [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], Radiological and Ultrasound Technology, Ultrasound Matrix Imaging, Phantoms, Imaging, Image and Video Processing (eess.IV), Transducers, FOS: Physical sciences, Applied Physics (physics.app-ph), Physics - Applied Physics, Acoustics, Electrical Engineering and Systems Science - Image and Video Processing, Physics - Medical Physics, Computer Science Applications, FOS: Electrical engineering, electronic engineering, information engineering, [PHYS.PHYS.PHYS-MED-PH]Physics [physics]/Physics [physics]/Medical Physics [physics.med-ph], Aberration Correction, Medical Physics (physics.med-ph), Electrical and Electronic Engineering, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Software, Distortion Matrix, Computational Ultrasound, [PHYS.PHYS.PHYS-DATA-AN]Physics [physics]/Physics [physics]/Data Analysis, Statistics and Probability [physics.data-an], Ultrasonography
Abstract: This is the second article in a series of two which report on a matrix approach for ultrasound imaging in heterogeneous media. This article describes the quantification and correction of aberration, i.e. the distortion of an image caused by spatial variations in the medium speed-of-sound. Adaptive focusing can compensate for aberration, but is only effective over a restricted area called the isoplanatic patch. Here, we use an experimentally-recorded matrix of reflected acoustic signals tosynthesize a set of virtual transducers. We then examine wave propagation between these virtual transducers and an arbitrary correction plane. Such wave-fronts consist of two components: (i) An ideal geometric wave-front linked to diffraction and the input focusing point, and; (ii) Phase distortions induced by the speed-of-sound variations. These distortions are stored in a so-called distortion matrix, the singular value decomposition of which gives access to an optimized focusing law at any point. We show that, by decoupling the aberrations undergone by the outgoing and incoming waves and applying an iterative strategy, compensation for even high-order and spatially-distributed aberrations can be achieved. After a numerical validation of the process, ultrasound matrix imaging (UMI) is applied to the in-vivo imaging of a gallbladder. A map of isoplanatic modes is retrieved and is shown to be strongly correlated with the arrangement of tissues constituting the medium. The corresponding focusing laws yield an ultrasound image with drastically improved contrast and transverse resolution. UMI thus provides a flexible and powerful route towards computational ultrasound., 20 pages, 11 figures
Published: 2022
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16. Can AI predict epithelial lesion categories via automated analysis of cervical biopsies: The TissueNet challenge?

Author: Nicolas Loménie, Capucine Bertrand, Rutger H.J. Fick, Saima Ben Hadj, Brice Tayart, Cyprien Tilmant, Isabelle Farré, Soufiane Z. Azdad, Samy Dahmani, Gilles Dequen, Ming Feng, Kele Xu, Zimu Li, Sophie Prevot, Christine Bergeron, Guillaume Bataillon, Mojgan Devouassoux-Shisheboran, Claire Glaser, Agathe Delaune, Séverine Valmary-Degano, Philippe Bertheau, Laboratoire d'Informatique Paris Descartes (LIPADE (URP_2517)), Université Paris Cité (UPCité), Morphologie et Images (MORPHEME), Inria Sophia Antipolis - Méditerranée (CRISAM), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institut de Biologie Valrose (IBV), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)-Signal, Images et Systèmes (Laboratoire I3S - SIS), Laboratoire d'Informatique, Signaux, et Systèmes de Sophia Antipolis (I3S), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)-Laboratoire d'Informatique, Signaux, et Systèmes de Sophia Antipolis (I3S), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Centre Hospitalier Régional Universitaire [Lille] (CHRU Lille), Modélisation, Information et Systèmes - UR UPJV 4290 (MIS), Université de Picardie Jules Verne (UPJV), CSIRO Indian Ocean Marine Research Centre [Australia], The University of Western Australia (UWA), Centre for Southern Hemisphere Oceans Research, Hobart, Tasmania, Australia, Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Yangtze Delta Region Institute of Tsinghua University [Zhejiang], AP-HP Hôpital Bicêtre (Le Kremlin-Bicêtre), Laboratoire CERBA [Saint Ouen l'Aumône], Institut Curie [Paris], Hospices Civils de Lyon (HCL), Université de Lyon - UDL, GenoSplice [Paris], Service d'Anatomie pathologique [CHRU Besançon], and Centre Hospitalier Régional Universitaire de Besançon (CHRU Besançon)
Subjects: Artificial intelligence, [SDV]Life Sciences [q-bio], Data challenge, Uterine cervix, Whole slide images, Health Informatics, Computer Science Applications, Pathology and Forensic Medicine, [INFO.INFO-AI]Computer Science [cs]/Artificial Intelligence [cs.AI]
Abstract: The French Society of Pathology (SFP) organized its first data challenge in 2020 with the help of the Health Data Hub (HDH). The organization of this event first consisted of recruiting nearly 5000 cervical biopsy slides obtained from 20 pathology centers. After ensuring that patients did not refuse to include their slides in the project, the slides were anonymized, digitized, and annotated by expert pathologists, and finally uploaded to a data challenge platform for competitors from around the world. Competing teams had to develop algorithms that could distinguish 4 diagnostic classes in cervical epithelial lesions. Among the many submissions from competitors, the best algorithms achieved an overall score close to 95%. The final part of the competition lasted only 6 weeks, and the goal of SFP and HDH is now to allow for the collection to be published in open access for the scientific community. In this report, we have performed a "post-competition analysis" of the results. We first described the algorithmic pipelines of 3 top competitors. We then analyzed several difficult cases that even the top competitors could not predict correctly. A medical committee of several expert pathologists looked for possible explanations for these erroneous results by reviewing the images, and we present their findings here targeted for a large audience of pathologists and data scientists in the field of digital pathology.
Published: 2022
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17. Crossover from renormalized to conventional diffusion near the 3D Anderson localization transition for light

Author: Cobus, Laura A., Maret, Georg, Aubry, Alexandre, Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Dodd-Walls Centre for Photonic and Quantum Technologies and Department of Physics, University of Auckland [Auckland], Fachbereich Physik [Konstanz], University of Konstanz, ANR-14-CE26-0032,LOVE,Localization d'Anderson des ondes vectoriels(2014), ANR-10-LABX-0024,WIFI,Institut Langevin : Ondes et Images, du Fondamental à l'Innovation(2010), European Project: 819261,REMINISCENCE, and European Project: 744840,SMART
Subjects: [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, FOS: Physical sciences, Disordered Systems and Neural Networks (cond-mat.dis-nn), Condensed Matter - Disordered Systems and Neural Networks, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Optics (physics.optics), Physics - Optics
Abstract: We report on anomalous light transport in the strong scattering regime. Using low-coherence interferometry, we measure the reflection matrix of titanium dioxide powders, revealing crucial features of strong optical scattering which can not be observed with transmission measurements: (i) a subdiffusive regime of transport at early times of flight that is a direct consequence of predominant recurrent scattering loops, and (ii) a crossover to a conventional, but extremely slow, diffusive regime at long times. These observations support previous predictions that near-field coupling between scatterers prohibits Anderson localization of light in three-dimensional disordered media., 13 pages, 7 figures
Published: 2022
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18. Etude du couplage entre deux antennes en chambre réverbérante

Author: Tamart, Meriem, Sarrazin, Francois, Richalot, Elodie, Davy, Matthieu, de Rosny, Julien, Université Gustave Eiffel, Electronique, Systèmes de communication et Microsystèmes (ESYCOM), Conservatoire National des Arts et Métiers [CNAM] (CNAM), HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Corrélation, [SPI]Engineering Sciences [physics], Chambre réverbérante, Caractérisation d'antennes
Abstract: International audience; Cette communication s’intéresse à une technique passive d’estimation du couplage entre deux antennes en réception dans une chambre réverbérante à brassage de modes. En exploitant l’inter-corrélation du champ électromagnétique diffus généré par une unique antenne en émission, nous démontrons que la réponse impulsionnelle entre deux antennes en réception peut être récupérée. Les résultats obtenus ouvrent la voie à une nouvelle technique de caractérisation d’antennes en chambre réverbérante.
Published: 2022

19. Localization of unbounded contacts on vibrating elastic plates

Author: Chloe Palerm, Julien de Rosny, Maxime Farin, Claire Prada, Institut Langevin - Ondes et Images (UMR7587) (IL), Sorbonne Université (SU)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Paris (UP)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], Physics, Acoustics and Ultrasonics, Covariance matrix, Acoustics, Ambient noise level, 02 engineering and technology, 021001 nanoscience & nanotechnology, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], Jet engine, law.invention, Noise, Matrix (mathematics), 020303 mechanical engineering & transports, Quality (physics), 0203 mechanical engineering, Arts and Humanities (miscellaneous), law, [PHYS.MECA.SOLID]Physics [physics]/Mechanics [physics]/Solid mechanics [physics.class-ph], [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Structural health monitoring, Shaker, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS
Abstract: Detection and localization of unbounded contacts in industrial structures are crucial for user safety. However, most structural health monitoring techniques are either invasive, power-consuming, or rely on time-varying baseline comparison. A passive acoustic method is proposed to localize unbounded contacts in plate-like structures, using the acoustic emissions by the contacts when they are excited by ambient noise. The technique consists of computing the correlation matrix of the signals measured by a set of receivers and applying to this matrix a beamforming algorithm accounting for flexural wave dispersion. To validate the technique, an experimental setup is developed in which three idealized unbounded contacts are created on a thin plate excited by a shaker. How the quality of the defect localization depends on the defect type, receiver number, and the characteristics of the noise is investigated. Finally, it is shown that the localization of unbounded contacts is possible using either an acoustic ambient noise source or a more realistic jet engine noise.
Published: 2020
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20. Experimental teaching — A tribute to Yves Couder by the example: stroboscopy and fluorescence lifetime with a fan

Author: Samuel Pautrel, Antonin Eddi, Paul Baconnier, Matthieu Blons, Suzie Protière, Emmanuel Fort, Physique et mécanique des milieux hétérogenes (UMR 7636) (PMMH), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Université Paris sciences et lettres (PSL), Institut Jean Le Rond d'Alembert (DALEMBERT), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Institut Langevin - Ondes et Images (UMR7587) (IL)
Subjects: [PHYS]Physics [physics], Mechanics of Materials, media_common.quotation_subject, 0103 physical sciences, General Materials Science, Art, 010306 general physics, 01 natural sciences, Humanities, 010305 fluids & plasmas, media_common
Abstract: International audience; Yves Couder created “PhyExp” at Paris Diderot University in 80s. This undergraduate course was meant to introduce experimental physics to students through projects. This approach proved fruitful both for students and teachers and has been replicated Ecole Supérieure de Physique et Chimie Industrielles (ESPCI). As a tribute to Yves, we report here the results obtained during this course about a specific project, namely the measurement of fluorescence lifetimes using stroboscopy and a fan. We obtain quantitative measurements for both Europium and Terbium that are commonly used in fluorescent tubes and we further study the variation of the lifetime with temperature.; Durant les années 80, Yves Couder a introduit une nouvelle méthode d’enseignement à l’Université Paris Diderot à travers le module “PhyExp”. Au cours de projets expérimentaux, les étudiants découvraient des problèmes originaux de physique ainsi que les méthodes permettant d’y apporter des solutions. Ce module a été reproduit à l’Ecole Supérieure de Physique et Chimie Industrielles (ESPCI) depuis 2014. En forme d’hommage à l’approche d’Yves Couder, nous pésentons ici les résultats obtenus par un groupe d’étudiants dont le projet consistait à mesurer des temps de vie de fluorescence avec des moyens limités (un ventilateur et un spectromètre). En utilisant une méthode stroboscopique, nous avons pu obtenir des mesures quantitatives pour les raies visibles de l’Europium et du Terbium, deux éléments présents dans les tubes fluorescents. Nous avons également évalué la variation de ces temps de vie avec la température.
Published: 2020
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21. Interaction des résonances de Fano et Fabry-Pérot dans des métasurfaces à période double

Author: Zhou Hagström, Joar, Maurel, Agnès, Pham, Kim, Institut des Sciences de la mécanique et Applications industrielles (IMSIA - UMR 9219), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-EDF R&D (EDF R&D), EDF (EDF)-EDF (EDF), Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Société Française d'Acoustique, and Laboratoire de Mécanique et d'Acoustique
Subjects: [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph]
Abstract: L’étude porte sur la modélisation des résonances de modes quasi-piégés couplés avec une onde incidente dans un réseau de diffraction acoustique de périodicité double sub-longueur onde. On considère un réseau de plaque à paroi rigide. Pour une périodicité simple, le réseau exhibe des résonances de type Fabry-Pérot [1]. En considérant une périodicité double, des résonances de Fano, caractérisées par une transmission parfaite suivie d’une réflexion parfaite très proche, apparaissent en brisant la symétrie de la cellule élémentaire [2]. On présente un modèle effectif obtenue en combinant des techniques d'homogénéi- sation à deux échelles et des développements asymptotiques raccordés capables de reproduire les propriétés du problème de diffraction avec haute précision. Le modèle fournit des expressions explicites des coefficients de refléxion de transmission permettant de décrire le comportement des modes quasi-piégés qui donnent lieu aux résonances Fano. [1] Marigo JJ, Maurel A. Second order homogenization of subwavelength stratified media including finite size effect, SIAM Journal on Applied Mathematics(2017). [2] Zhou Hagström J, Maurel A, Pham K. The interplay between Fano and Fabry-Perot resonances in dual-period metagratings, Proc. R. Soc. A. (2021).
Published: 2022

22. Développement d’une méthode de dénombrement des vésicules membranaires dans les écosystèmes lacustres

Author: Mone, Anne, Royet, Violaine, Hennequin, C., Debroas, Didier, Boccara, Martine, Boccara, Claude, Ravet, Viviane, Laboratoire Microorganismes : Génome et Environnement (LMGE), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Laurent-Emmanuel MONFOULET-INRAE-UNH (Organisateur)
Subjects: [SDV.AEN]Life Sciences [q-bio]/Food and Nutrition, ComputingMilieux_MISCELLANEOUS
Abstract: National audience
Published: 2022
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23. Room temperature optically pumped GeSn microdisk lasers

Author: J. Chrétien, Q. M. Thai, M. Frauenrath, L. Casiez, A. Chelnokov, V. Reboud, J. M. Hartmann, M. El Kurdi, N. Pauc, V. Calvo, Silicon Nanoelectronics Photonics and Structures (SiNaps), PHotonique, ELectronique et Ingénierie QuantiqueS (PHELIQS), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre de Nanosciences et de Nanotechnologies (C2N), and Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], [SPI]Engineering Sciences [physics], Physics and Astronomy (miscellaneous), Lasers, Alloys, Optoelectronic devices, Thermal effects
Abstract: International audience; GeSn alloys are promising materials for light emitters monolithically grown on silicon. In this work, we demonstrate room temperature (RT) lasing in a GeSn hetero-structure with 17.2% of Sn. We report a threshold of 3:27MWcm2 at 305K with peak emission at 353meV. We ascribe these improvements to a higher tin concentration in the GeSn active layer with lower Sn content barriers on each side and to a better thermal dissipation provided by an adapted pedestal architecture beneath the GeSn micro-disk. This outcome is a major milestone for a fully integrated group-IV semiconductor laser on Si.
Published: 2022
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24. Optical phase modulation by natural eye movements: application to time-domain FF-OCT image retrieval

Author: Viacheslav Mazlin, Peng Xiao, Kristina Irsch, Jules Scholler, Kassandra Groux, Kate Grieve, Mathias Fink, A. Claude Boccara, Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), ICN2 - Institut Catala de Nanociencia i Nanotecnologia (ICN2), Universitat Autònoma de Barcelona (UAB), Institut de la Vision, Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts (CHNO), and Gestionnaire, HAL Sorbonne Université 5
Subjects: genetic structures, [SDV.MHEP.OS] Life Sciences [q-bio]/Human health and pathology/Sensory Organs, FOS: Physical sciences, Medical Physics (physics.med-ph), sense organs, [SDV.MHEP.OS]Life Sciences [q-bio]/Human health and pathology/Sensory Organs, Physics - Medical Physics, Atomic and Molecular Physics, and Optics, Article, eye diseases, Biotechnology
Abstract: International audience; Eye movements are commonly seen as an obstacle to high-resolution ophthalmic imaging. In this context we study the natural axial movements of the in vivo human eye and show that they can be used to modulate the optical phase and retrieve tomographic images via time-domain full-field optical coherence tomography (TD-FF-OCT). This approach opens a path to a simplified ophthalmic TD-FF-OCT device, operating without the usual piezo motor-camera synchronization. The device demonstrates in vivo human corneal images under the different image retrieval schemes (2-phase and 4-phase) and different exposure times (3.5 ms, 10 ms, 20 ms). Data on eye movements, acquired with a spectral-domain OCT with axial eye tracking (180 B-scans/s), are used to study the influence of ocular motion on the probability of capturing high-signal tomographic images without phase washout. The optimal combinations of camera acquisition speed and amplitude of piezo modulation are proposed and discussed.
Published: 2022
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25. Weight of single and recurrent scattering in the reflection matrix of complex media

Author: Cécile Brütt, Alexandre Aubry, Benoît Gérardin, Arnaud Derode, Claire Prada, Safran Tech, Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), The PhD thesis of Cécile Brütt was funded by Safran Tech, ANR-10-LABX-0024,WIFI,Institut Langevin : Ondes et Images, du Fondamental à l'Innovation(2010), and European Project: 819261,REMINISCENCE
Subjects: [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], FOS: Physical sciences, [PHYS.COND.CM-DS-NN]Physics [physics]/Condensed Matter [cond-mat]/Disordered Systems and Neural Networks [cond-mat.dis-nn], Physics - Applied Physics, Applied Physics (physics.app-ph), Disordered Systems and Neural Networks (cond-mat.dis-nn), Condensed Matter - Disordered Systems and Neural Networks, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, [PHYS.PHYS.PHYS-DATA-AN]Physics [physics]/Physics [physics]/Data Analysis, Statistics and Probability [physics.data-an]
Abstract: In a heterogeneous medium, the wavefield can be decomposed as an infinite series known as the Born expansion. Each term of the Born expansion corresponds to a scattering order, it is thus theoretically possible to discriminate single and multiple scattering field components. Experimentally, what is actually measured is the total field in which all scattering orders interfere. Conventional imaging methods usually rely on the assumption that the multiple scattering contribution can be disregarded. In a back-scattering configuration, this assumption is valid for small depths, and begins to fail for depths larger than the scattering mean-free path $\ell_s$. It is therefore a key issue to estimate the relative amount of single and multiple scattering in experimental data. To this end, a single scattering estimator $\hat{\rho}$ computed from the reflection matrix has been introduced in order to assess the weight of single scattering in the backscattered wavefield. In this article, the meaning of this estimator is investigated and a particular attention is given to recurrent scattering. In a diffraction-limited experiment, a multiple scattering sequence is said to be recurrent if the first and last scattering events occur in the same resolution cell. Recurrent scattering is shown to be responsible for correlations between single scattering and higher scattering orders of the Born expansion, inducing a bias to the estimator $\hat{\rho}$ that should rather be termed confocal scattering ratio. Interestingly, a more robust estimator is built by projecting the reflection matrix in a focused basis. The argument is sustained by numerical simulations as well as ultrasonic data obtained around 1.5~MHz in a model medium made of nylon rods immersed in water. From a more general perspective, this work raises fundamental questions about the impact of recurrent scattering on wave imaging., Comment: 17 pages, 11 figures
Published: 2022
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26. Dynamic Cell Imaging: application to the diatom Phaeodactylum tricornutum under environmental stresses

Author: H. Bey, S. Liu, R. G. Dorrell, F. Charton, Chris Bowler, C. Boccara, m. Boccara, H. Cruz de Carvalho, Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de biologie de l'ENS Paris (IBENS), Département de Biologie - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), ANR-21-CE02-0014,PanArctica,Caractérisation phylogénétique, écologique et physiologique de le pan-génome des algues Arctiques(2021), Dorrell, Richard, and Caractérisation phylogénétique, écologique et physiologique de le pan-génome des algues Arctiques - - PanArctica2021 - ANR-21-CE02-0014 - AAPG2021 - VALID
Subjects: iron limitation, Materials science, biology, lipid droplets, Plant Science, [SDV.BC.BC]Life Sciences [q-bio]/Cellular Biology/Subcellular Processes [q-bio.SC], Aquatic Science, biology.organism_classification, Chloroplast membrane, Chloroplast, light scattering, Light scattering, phosphate limitation, Wavelength, endoplasmic reticulum, Diatom, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, Lipid droplet, Organelle, [SDV.BC.BC] Life Sciences [q-bio]/Cellular Biology/Subcellular Processes [q-bio.SC], Phaeodactylum tricornutum, Biological system, [SDV.MP] Life Sciences [q-bio]/Microbiology and Parasitology, Brownian motion, organelle movement
Abstract: The dynamic movement of cell organelles is an important and poorly understood component of cellular organisation and metabolism. In this work we present a non-invasive non-destructive method (Dynamic Cell Imaging, DCI) based on light scattering and interferometry to monitor dynamic events within photosynthetic cells using the diatom Phaeodactylum tricornutum as a model system. For this monitoring we acquire few seconds movies of the signals that are related to the motion of dynamic structures within the cell (denoted scatterers), followed by a statistical analysis of each pixel time series. Illuminating P.tricornutum with LEDs of different wavelengths associated to short pulsed or continuous-wave modes of illumination revealed that dynamic movements depend on chloroplast activity, in agreement with the reduction in the number of pixels with dynamic behaviour after addition of photosystemII inhibitors. We studied P. tricornutum under two environmentally relevant stresses, iron and phosphate deficiency. The major dynamic sites were located within lipid droplets and chloroplast envelope membranes. By comparing standard deviation and cumulative sum analysis of the time series, we showed that within the droplets two types of scatterer movement could be observed: random motions (Brownian type) but also anomalous movements corresponding to a drift which may relate to molecular fluxes within a cell. The method appears valuable for studying the effects of various environments on a large variety of microalgae in the laboratory as well as in natural aquatic environments.HIGHLIGHTsLight scattering an alternative to fluorescence to rapidly evidence dynamic processes.Lipid droplets the major metabolic active sites under stressA non-destructive visualisation method for laboratory microalgae and aquatic samples..SIGNIFICANCE STATEMENTLight scattering could be an alternative to fluorescence techniques to study dynamic processes within photosynthetic cells. We used a method combining light scattering and interferometry to analyse movements of intracellular scatterers in the marine diatom Phaedactylum tricornutum under two environmentally relevant stresses, iron and phosphate deficiency. Lipid droplets were the major active sites under stress. The method which is rapid and non destructive can be broadly expanded to study other microalgae and their stress responses, in the laboratory and in aquatic environments.
Published: 2022
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27. Time Reversal Precoding at SubTHz Frequencies: Experimental Results on Spatiotemporal Focusing

Author: Ali Mokh, Julien De Rosny, George C. Alexandropoulos, Ramin Khayatzadeh, Abdelwaheb Ourir, Mohamed Kamoun, Arnaud Tourin, Mathias Fink, Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL), Institut Langevin - Ondes et Images (UMR7587) (IL), Sorbonne Université (SU)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Paris (UP)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS), National and Kapodistrian University of Athens (NKUA), HUAWEI Technologies France (HUAWEI), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)
Subjects: receive spatial modulation, Computer Science - Information Theory, Time reversal, terahertz communications, Electrical Engineering and Systems Science - Signal Processing, spatiotemporal focusing, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing
Abstract: Due to availability of large spectrum chunks, the sub-TeraHertz (subTHz) frequency band can support Ultra-WideBand (UWB) wireless communications, paving the way for unprecedented increase in the wireless network capacity. This fact is expected to be the next breakthrough for the upcoming sixth Generation (6G) standards. However, the technology of subTHz transceivers is not yet mature enough to apply the advanced signal processing currently being implemented for millimeter wave wireless communications. In this paper, we consider the Time Reversal (TR) precoding technique, which provides simple and robust processing capable to offer highly focalized in time and space UWB waveforms, exploiting the spatial diversity of wireless channels. We first investigate experimentally the performance of subTHz TR focusing in complex media inside a leaking reverberation cavity. We then combine TR with received spatial modulation to realize data communication using a simple non-coherent receiver with two antennas. Our results showcase the capability of TR to offer focusing in time in the order of few nanoseconds and in space in the order of less than 1 mm., Comment: 5 pages, 5 figures, presented at IEEE Conference on Standards for Communications and Networking 2021
Published: 2021

28. Ultrasound scattering from cell-pellet biophantoms and ex vivo tumors provides insight into the cellular structure involved in scattering

Author: Muleki Seya, Pauline, Muleki-Seya, Pauline, O'Brien, William, Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Application des ultrasons à la thérapie (LabTAU), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre Léon Bérard [Lyon]-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Bioacoustics Research Laboratory, Bioacoustics Research Laboratory, Dept Elect. and Comp. Engineering, Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA), Imagerie Ultrasonore, Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), University of Illinois at Urbana-Champaign [Urbana], University of Illinois System, and MULEKI SEYA, PAULINE
Subjects: Materials science, Acoustics and Ultrasonics, Quantitative Biology::Tissues and Organs, Physics::Medical Physics, Normal Distribution, Article, Quantitative Biology::Cell Behavior, symbols.namesake, Nuclear magnetic resonance, Neoplasms, medicine, Scattering parameters, Humans, Electrical and Electronic Engineering, Instrumentation, ComputingMilieux_MISCELLANEOUS, Ultrasonography, Scattering, Histological Techniques, Cellular Structures, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], Cell Pellet, medicine.anatomical_structure, Volume fraction, symbols, [PHYS.MECA.ACOU] Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], Structure factor, Nucleus, Gaussian network model, Ex vivo
Abstract: International audience; The histologically identifiable cellular structure(s) involved in ultrasonic scattering is(are) yet to be uniquely identified. The study quantifies six possible cellular scattering parameters, namely, cell and nucleus radii and their respective cell and nucleus volume fractions as well as a combination of cell and nucleus radii and their volume fraction. The six cellular parameters are each derived from four cell lines (4T1, JC, LMTK, and MAT) and two tissue types (cell-pellet biophantom and ex vivo tumor). Optical histology and quantitative ultrasound (QUS), both independent approaches, are used to yield these cellular parameters. QUS scatterer parameters are experimentally determined using two ultrasonic scattering models: the spherical Gaussian model (GM) and the structure factor model (SFM) to yield insight about scattering from nuclei only and cells only. GM is a classical ultrasonic scattering model to evaluate QUS parameters and is well adapted for diluted media. SFM is adapted for dense media to estimate reasonably well scatterer parameters of cellular structures from ex vivo tissue. Nucleus and cell radii and volume fractions are measured optically from histology. They were used as inputs to calculate BSC for scattering from cells, nuclei, and both cells and nuclei. The QUS-derived scatterers (radii and volume fractions) distributions were then compared to the optical histology scatterer parameters derived from these calculated BSCs. The results suggest scattering from cells only (LMTK and MAT) or both cells and nuclei (4T1 and JC) for cell-pellet biophantoms and scattering from nuclei only for tumors.
Published: 2021
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29. Partial-field illumination ophthalmoscope: improving the contrast of a camera-based retinal imager

Author: Serge Meimon, Léa Krafft, Michel Paques, Laurent M. Mugnier, Yann Lai-Tim, Pedro Mecê, Elena Gofas-Salas, Olivier Thouvenin, DOTA, ONERA, Université Paris Saclay [Châtillon], ONERA-Université Paris-Saclay, Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts (CHNO), Institut de la Vision, Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), ANR-18-CE19-0010,EyeWin,L'oeil, une fenêtre ouverte sur le couplage neuro-vasculaire(2018), ANR-15-RHUS-0001,LIGHT4DEAF,ECLAIRER LA SURDITÉ : UNE APPROCHE HOLISTIQUE DU SYNDROME D'USHER(2015), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPC)
Subjects: Optics and Photonics, Microscope, Laser scanning, Computer science, media_common.quotation_subject, FOS: Physical sciences, Signal-To-Noise Ratio, 01 natural sciences, Signal, Retina, law.invention, 010309 optics, Contrast Sensitivity, 03 medical and health sciences, [SPI]Engineering Sciences [physics], 0302 clinical medicine, Optics, law, 0103 physical sciences, Photography, Contrast (vision), Humans, Electrical and Electronic Engineering, Adaptive optics, Engineering (miscellaneous), Lighting, media_common, [PHYS]Physics [physics], Spatial filter, Pixel, business.industry, Ophthalmoscopes, Equipment Design, Physics - Medical Physics, Atomic and Molecular Physics, and Optics, 030221 ophthalmology & optometry, Medical Physics (physics.med-ph), business, Optics (physics.optics), Physics - Optics
Abstract: Effective and accurate in-vivo diagnosis of retinal pathologies requires high performance imaging devices, combining a large field of view and the ability to discriminate the ballistic signal from the diffuse background in order to provide a highly contrasted image of the retinal structures. Here, we have implemented the Partial-Field Illumination Ophthalmoscope, a patterned illumination modality, integrated on a high pixel rate adaptive optics full-field microscope. This non-invasive technique enables us to mitigate the low signal-to-noise ratio, intrinsic of full-field ophthalmoscopes, by partially illuminating the retina with complementary patterns to reconstruct a wide field image. This new modality provides an image contrast spanning from the full-field to the confocal contrast, depending on the pattern size. As a result, it offers various trade-offs in terms of contrast and acquisition speed, guiding the users towards the most efficient system for a particular clinical application., 6 pages, 5 figures
Published: 2021

30. Monitoring saltwater corrosion of steel using ultrasonic coda wave interferometry with temperature control

Author: Maxime Farin, Emmanuel Moulin, Lynda Chehami, Farouk Benmeddour, Cyril Nicard, Pierre Campistron, Olivier Bréhault, Lucie Dupont, Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-JUNIA (JUNIA), Université catholique de Lille (UCL)-Université catholique de Lille (UCL), Transduction, Propagation et Imagerie Acoustique - IEMN (TPIA - IEMN), INSA Institut National des Sciences Appliquées Hauts-de-France (INSA Hauts-De-France), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Université catholique de Lille (UCL)-Université catholique de Lille (UCL)-Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-JUNIA (JUNIA), Institut National des Sciences Appliquées (INSA), Unité Matériaux et Transformations - UMR 8207 (UMET), Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Matériaux et Acoustiques pour MIcro et NAno systèmes intégrés - IEMN (MAMINA - IEMN), and This work was supported by the European project Interreg 2 Seas, Antwerp Maritime Academy, SOCORRO . The authors thank Ingrid Proriol-Serre, David Balloy, Guillaume Delaplace and Simon Khelissa (Univ. Lille, CNRS, INRAE, Centrale Lille, UMR 8207 - UMET - Unité Matériaux et Transformations, F-59000 Lille, France) for helpful discussions.
Subjects: Corrosion, Non destructive testing, [SPI]Engineering Sciences [physics], Acoustics and Ultrasonics, Coda wave interferometry
Abstract: International audience; Assessing corrosion is crucial in the petrochemical and marine industries. Usual ultrasonic methods based on pulse-echo and guided waves to detect corrosion lack of precision and struggle in structures with a complex shape. In this paper, a complementary and sensitive ultrasonic method based on coda wave interferometry is presented to detect and quantify thickness loss caused by saltwater corrosion of a steel sample. The method consists in exciting the sample and measuring periodically the scattered coda signal. Correlation of the coda signal with a reference taken for the sample initial state permits the monitoring of corrosion spread with a high accuracy. A laboratory experiment is conducted with two steel samples immersed in saltwater with coda and temperature measured simultaneously. One of the samples is protected from corrosion and is used as a control sample to determine the influence of temperature on the coda signals. It is shown that the coda signals on the corroded sample can be temperature-corrected using the temperature measurement only. A control sample is not needed. A good correlation is found between a parameter quantifying the stretching of the coda over time and the corrosion surface, which is monitored with a camera. Finally, a simple theoretical model of coda signal is proposed to quantify the real-time average corrosion rate during the experiment with a sub-micrometric precision. The estimated final average corrosion depth is validated by independent depth profile measurements. The uncertainties and sensitivity of the presented method are investigated.
Published: 2021
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31. Partial-Field Illumination Ophthalmoscope: improving the contrast of a camera-based retinal imager

Author: Krafft, Léa, Gofas-Salas, Elena, Lai-Tim, Yann, Paques, Michel, Mugnier, Laurent, Thouvenin, Olivier, Mecê, Pedro, Meimon, Serge, DOTA, ONERA, Université Paris Saclay [Châtillon], ONERA-Université Paris-Saclay, Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts (CHNO), Institut de la Vision, Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), ANR-18-CE19-0010,EyeWin,L'oeil, une fenêtre ouverte sur le couplage neuro-vasculaire(2018), ANR-15-RHUS-0001,LIGHT4DEAF,ECLAIRER LA SURDITÉ : UNE APPROCHE HOLISTIQUE DU SYNDROME D'USHER(2015), WIBAUX, Laurine, APPEL À PROJETS GÉNÉRIQUE 2018 - L'oeil, une fenêtre ouverte sur le couplage neuro-vasculaire - - EyeWin2018 - ANR-18-CE19-0010 - AAPG2018 - VALID, and ECLAIRER LA SURDITÉ : UNE APPROCHE HOLISTIQUE DU SYNDROME D'USHER - - LIGHT4DEAF2015 - ANR-15-RHUS-0001 - RHUS - VALID
Subjects: Applications cliniques, [PHYS]Physics [physics], Spatial filtering, Balayage laser, Spatial light modulators, [SPI] Engineering Sciences [physics], Systèmes d'imagerie, Clinical applications, [PHYS] Physics [physics], Filtrage spatial, [SPI]Engineering Sciences [physics], Tomographie par cohérence optique plein champ, Imaging systems, Modulateurs de lumière spatiaux, Laser scanning, Full field optical coherence tomography
Abstract: Effective and accurate in vivo diagnosis of retinal pathologies requires high performance imaging devices, combining a large field of view and the ability to discriminate the ballistic signal from the diffuse background in order to provide a highly contrasted image of the retinal structures. Here, we have implemented the partial-field illumination ophthalmoscope, a patterned illumination modality, integrated to a high pixel rate adaptive optics full-field microscope. This non-invasive technique enables us to mitigate the low signal-to-noise ratio, intrinsic of full-field ophthalmoscopes, by partially illuminating the retina with complementary patterns to reconstruct a wide-field image. This new, to the best of our knowledge, modality provides an image contrast spanning from the full-field to the confocal contrast, depending on the pattern size. As a result, it offers various trade-offs in terms of contrast and acquisition speed, guiding the users towards the most efficient system for a particular clinical application., Le diagnostic efficace et précis des pathologies rétiniennes, in-vivo, requière l’utilisation de systèmes d’imagerie haute performance, qui allient un grand champ d’imagerie et la capacité à discriminer le signal balistique du fond diffus afin d’obtenir des images des structures rétiniennes hautement contrastées. Dans cette étude, nous avons implémenté l'ophtalmoscope à illumination partielle du champ (Partial-Field Illumination Ophtalmoscope), une modalité d’illumination basée sur la projection de motifs, intégrée à un ophtalmoscope plein champ à haut débit de pixels. Cette technique non-invasive permet de pallier le faible rapport signal sur bruit, intrinsèque à l’ophtalmoscope plein champ, en illuminant partiellement la rétine avec des motifs complémentaires afin de reconstruire une image grand champ. Cette nouvelle modalité d’imagerie offre différents contrastes d’imagerie s’étendant entre le contraste du plein champ et le contraste du confocal, en fonction de la nature du motif projeté. Ainsi, elle propose différents compromis en terme de contraste d'imagerie et de vitesse d’acquisition et oriente l’utilisateur vers le système le plus efficace pour une application clinique particulière.
Published: 2021

32. Optomechanical backaction processes in a bulk rare-earth doped crystal

Author: Louchet-Chauvet, Anne, Verlot, Pierre, Poizat, Jean-Philippe, Chanelière, Thierry, Laboratoire Aimé Cotton (LAC), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan), Institut Langevin - Ondes et Images (UMR7587) (IL), Sorbonne Université (SU)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Paris (UP)-Centre National de la Recherche Scientifique (CNRS), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon, Nanophysique et Semiconducteurs (NPSC), Institut Néel (NEEL), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), and Université Grenoble Alpes (UGA)
Subjects: Condensed Matter - Materials Science, Quantum Physics, [PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], Atomic Physics (physics.atom-ph), Materials Science (cond-mat.mtrl-sci), FOS: Physical sciences, Physics::Optics, Quantum Physics (quant-ph), Physics - Atomic Physics, Physics - Optics, Optics (physics.optics)
Abstract: We investigate a novel hybrid system composed of an ensemble of room temperature rare-earth ions embedded in a bulk crystal, intrinsically coupled to internal strain via the surrounding crystal field. We evidence the generation of a mechanical response under resonant light excitation. Thanks to an ultra-sensitive time- and space-resolved photodeflection setup, we interpret this motion as the sum of two resonant optomechanical backaction processes: a conservative, piezoscopic process induced by the optical excitation of a well-defined electronic configuration, and a dissipative, non-radiative photothermal process related to the phonons generated throughout the atomic population relaxation. Parasitic heating processes, namely off-resonant dissipative contributions, are absent. This work demonstrates an unprecedented level of control of the conservative and dissipative relative parts of the optomechanical backaction, confirming the potential of rare-earth-based systems as promising hybrid mechanical systems.
Published: 2021

33. Hidden statistics in speckle patterns

Author: Rémi Carminati, Institut Langevin - Ondes et Images (UMR7587) (IL), Sorbonne Université (SU)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Paris (UP)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Speckle pattern, [SPI]Engineering Sciences [physics], Optics, Scattering, business.industry, business, Intensity (physics)
Abstract: International audience; Scattering of coherent light from a disordered material produces a complex distribution of intensity known as a speckle pattern. Speckle patterns are not as random as they appear at first glance. Their statistical properties exhibit universal features, as already recognized in the first paper on laser speckle. The existence of short-range and long-range spatial correlations in speckles has been shown to be fundamental in wave physics. It has also led to the emergence of novel approaches for imaging through scattering media.
Published: 2021
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34. Open birdcage coil for head imaging at 7T

Author: Nikolai I. Avdievich, A. Nikulin, Abdelwaheb Ourir, Alexandre Vignaud, D. Berrahou, Julien de Rosny, Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Service NEUROSPIN (NEUROSPIN), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), High-Field MR Center, Max Planck Institute for Biological Cybernetics, and Multiwave Imaging
Subjects: ultra-high-field MRI, Acoustics, brain imaging, Tracking (particle physics), Imaging phantom, 030218 nuclear medicine & medical imaging, head coil, 03 medical and health sciences, 0302 clinical medicine, Humans, Radiology, Nuclear Medicine and imaging, [PHYS.COND.CM-MSQHE]Physics [physics]/Condensed Matter [cond-mat]/Mesoscopic Systems and Quantum Hall Effect [cond-mat.mes-hall], Physics, open coil, Phantoms, Imaging, Homogeneity (statistics), Brain, Specific absorption rate, Equipment Design, Magnetic Resonance Imaging, Transfer matrix, Symmetry (physics), Magnetic field, birdcage coil, Electromagnetic coil, Head, 030217 neurology & neurosurgery
Abstract: Purpose: To theoretically describe, design, and test the new geometry of the birdcage coil for 7 Tesla anatomical brain imaging, which includes a large window on top, without deliberately jeopardizing its homogeneity and efficiency. This opencage will not only improve patient comfort but also enable the volunteer to follow functional MRI stimuli. This design could also facilitate the tracking of patient compliance and enable better correction of the movement. Methods: Via the transfer matrix approach, a birdcage-like coil with a nonperiodic distribution of rungs is constructed with optimized currents in the coil rungs. Subsequently, the coil is adjusted in full-wave simulations. Then, the coil is assembled, fine-tuned, and matched on the bench. Finally, these results are confirmed experimentally on a phantom and in vivo. Results: Indeed, the computed isolation of -14.9 dB between the feeding ports of the coil and the symmetry of the circular polarized mode pattern transmit RF magnetic field ( B+1 ) showed that the coil was properly optimized. An experimental assessment of the developed coil showed competitive transmit efficiency and coverage compared with the conventional birdcage coil of similar size. Conclusion: The proposed opencage coil can be designed and work without a dramatic drop of performance in terms of the B+1 field homogeneity, transmit efficiency ( (B+1) / √Pref ), peak local specific absorption rate ( SAR10g ) and SAR efficiency ( (B+1) / √SAR10g ).
Published: 2021
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35. Few-Molecule Strong Coupling with Dimers of Plasmonic Nanoparticles Assembled on DNA

Author: Elise Y Gayet, Sébastien Bidault, Nemanja Markešević, Nicolas Bonod, Jeanne Heintz, Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut FRESNEL (FRESNEL), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Sorbonne Université (SU)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Paris (UP)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU)
Subjects: Materials science, Nanostructure, General Physics and Astronomy, Ionic bonding, Metal Nanoparticles, Physics::Optics, 02 engineering and technology, 01 natural sciences, Molecular physics, plasmonics, 0103 physical sciences, strong coupling, General Materials Science, DNA nanotechnology, 010306 general physics, Spectroscopy, Plasmon, Plasmonic nanoparticles, dye molecules, Scattering, General Engineering, DNA, self-assembly, 021001 nanoscience & nanotechnology, scattering spectroscopy, Colloidal gold, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Self-assembly, Gold, 0210 nano-technology
Abstract: International audience; Hybrid nanostructures, in which a known number of quantum emitters are strongly coupled to a plasmonic resonator, should feature optical properties at room temperature such as few-photon nonlinearities or coherent superradiant emission. We demonstrate here that this coupling regime can only be reached with dimers of gold nanoparticles in stringent experimental conditions, when the interparticle spacing falls below 2 nm. Using a short transverse DNA double-strand, we introduce 5 dye molecules in the gap between two 40 nm gold particles and actively decrease its length down to sub-2 nm values by screening electrostatic repulsion between the particles at high ionic strengths. Single-nanostructure scattering spectroscopy then evidences the observation of a strong-coupling regime in excellent agreement with electrodynamic simulations. Furthermore, we highlight the influence of the planar facets of polycrystalline gold nanoparticles on the probability of observing strongly coupled hybrid nanostructures.
Published: 2021
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36. Transient critical regime for light near the three-dimensional Anderson transition

Author: Cobus, Laura A., Maret, Georg, Aubry, Alexandre, Institut Langevin - Ondes et Images (UMR7587) (IL), Sorbonne Université (SU)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Paris (UP)-Centre National de la Recherche Scientifique (CNRS), Dodd-Walls Centre for Photonic and Quantum Technologies and Department of Physics, University of Auckland [Auckland], Fachbereich Physik [Konstanz], and University of Konstanz
Subjects: [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat]
Abstract: 13 pages, 9 figures; We report on anomalous light transport in the strong scattering regime. Using low-coherence interferometry, we measure the reflection matrix of titanium dioxide powders, revealing crucial features of strong optical scattering which can not be observed with transmission measurements: (i) a subdiffusive regime of transport at early times of flight that is a direct consequence of predominant recurrent scattering loops, and (ii) a transition to a conventional, but extremely slow, diffusive regime at long times. These observations support previous predictions that near-field coupling between scatterers prohibits Anderson localization of light in three-dimensional disordered media.
Published: 2021

37. Effective model for elastic waves in a substrate supporting a array of plates/beams with flexural and longitudinal resonances

Author: Agnès Maurel, Jean-Jacques Marigo, Kim Pham, Sébastien Guenneau, Institut Jean Le Rond d'Alembert (DALEMBERT), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut Polytechnique de Paris (IP Paris), Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut FRESNEL (FRESNEL), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), and ANR-19-CE08-0006,METARESO,Propagation d'ondes dans des Métamatériaux Résonants(2019)
Subjects: Asymptotic analysis, 02 engineering and technology, 01 natural sciences, Homogenization (chemistry), Displacement (vector), Flexural strength, 0103 physical sciences, General Materials Science, 2010 MSC: 00-01, 99-00, Boundary value problem, 010306 general physics, Physics, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Scattering, Mechanical Engineering, elastic waves, Metamaterial, Mechanics, 021001 nanoscience & nanotechnology, metasurfaces, asymptotic analysis, metamaterials, Mechanics of Materials, multimodal methods, Reflection (physics), 0210 nano-technology
Abstract: In a previous study (Marigo et al. in J. Mech. Phys. Solids 143:104029, 2020) we have studied the effect of a periodic array of subwavelength plates or beams over a semi-infinite elastic ground on the propagation of waves hitting the interface. The study was restricted to the low frequency regime where only flexural resonances take place. Here, we present a generalization to higher frequencies which allows us to account for both flexural and longitudinal resonances and to evaluate their interplay. An effective model is obtained using asymptotic analysis and homogenization techniques, which can be expressed in terms of the ground alone with an effective dynamic (frequency-dependent) boundary conditions of the Robin’s type. For an in-plane wave at oblique incidence, the scattered displacement fields and the reflection coefficients are obtained in closed forms and their effectiveness to reproduce the actual scattering is inspected by comparison with direct numerics in a two-dimensional setting.
Published: 2021
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38. Retinal blood flow reversal quantitatively monitored in out-of-plane vessels with laser Doppler holography

Author: Michel Paques, Michael Atlan, Leo Puyo, Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts (CHNO), Institut de la Vision, Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut Langevin - Ondes et Images (UMR7587) (IL), Sorbonne Université (SU)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Paris (UP)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Gestionnaire, HAL Sorbonne Université 5
Subjects: Science, Holography, FOS: Physical sciences, 01 natural sciences, Grayscale, Article, law.invention, 010309 optics, 03 medical and health sciences, symbols.namesake, 0302 clinical medicine, Optics, law, 0103 physical sciences, FOS: Electrical engineering, electronic engineering, information engineering, Laser-Doppler Flowmetry, Humans, [SDV.MHEP.OS]Life Sciences [q-bio]/Human health and pathology/Sensory Organs, Eye diseases, Physics, Multidisciplinary, business.industry, Choroid, Image and Video Processing (eess.IV), Imaging and sensing, Retinal Vessels, Blood flow, Laser Doppler velocimetry, Electrical Engineering and Systems Science - Image and Video Processing, Physics - Medical Physics, Optical axis, Cardiovascular diseases, Flow (mathematics), [SDV.MHEP.OS] Life Sciences [q-bio]/Human health and pathology/Sensory Organs, Temporal resolution, 030221 ophthalmology & optometry, symbols, Medicine, Medical Physics (physics.med-ph), business, Doppler effect, Blood Flow Velocity
Abstract: Laser Doppler holography is a planar blood flow imaging technique recently introduced in ophthalmology to image human retinal and choroidal blood flow non-invasively. Here we present a digital method based on the Doppler spectrum asymmetry that reveals the local direction of blood flow with respect to the optical axis in out-of-plane vessels. This directional information is overlaid on standard grayscale blood flow images to depict flow moving towards the camera in red and flow moving away from the camera in blue, as in ultrasound color Doppler imaging. We show that thanks to the strong contribution of backscattering to the Doppler spectrum in out-of-plane vessels, the local axial direction of blood flow can be revealed with a high temporal resolution, which enables us to evidence pathological blood flow reversals. We also demonstrate the use of optical Doppler spectrograms to quantitatively monitor retinal blood flow reversals.
Published: 2021
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39. Multimodal method for the scattering by an array of plates connected to an elastic half-space

Author: Kim Pham, Agnès Maurel, Institut Langevin - Ondes et Images, Université Paris Diderot - Paris 7 (UPD7)-ESPCI ParisTech-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Ecole Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris-Sciences-et-Lettres (https://www.psl.eu/), Institut des Sciences de la mécanique et Applications industrielles (IMSIA - UMR 9219), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-EDF R&D (EDF R&D), EDF (EDF)-EDF (EDF), École Nationale Supérieure de Techniques Avancées (ENSTA Paris), Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Université Paris sciences et lettres (PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-EDF R&D (EDF R&D)
Subjects: Physics, Surface (mathematics), Acoustics and Ultrasonics, Scattering, Mathematical analysis, Resonance, [PHYS.MECA]Physics [physics]/Mechanics [physics], 02 engineering and technology, Half-space, 021001 nanoscience & nanotechnology, 01 natural sciences, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], 010305 fluids & plasmas, Matrix (mathematics), Arts and Humanities (miscellaneous), Free surface, 0103 physical sciences, Reflection (physics), Boundary value problem, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS
Abstract: An accurate and numerically inexpensive method is presented to calculate the reflection of in-plane waves at the free surface of an elastic substrate supporting a periodic array of plates. The method is based on the expansions of the elastic fields on the pseudo-periodic modes in the substrate and on the Lamb modes in the plates. These expansions involve unknown amplitudes which are determined by simple matrix inversion when accounting for the boundary conditions at the surface of the substrate and at the free edges of the plates. Exemplifying results are reported in a wide range of frequency covering two resonances of the plates which are analyzed: a flexural resonance of slender bodies and the quasi-resonance of the so-called edge mode. The convergence of the method is inspected quantitatively; it is shown that it is good in view of the fact that the stress is singular at the corners of the plates in contact with the substrate. In particular, the scattering coefficients converge as 1 / N s 3 / 2 with N s the truncation of the expansions.
Published: 2019
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40. Selective remote excitation of complex structures using time reversal in audible frequency range

Author: Maxime Farin, Julien de Rosny, Claire Prada, Institut de Physique du Globe de Paris (IPGP), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS), Institut Langevin - Ondes et Images, Université Paris Diderot - Paris 7 (UPD7)-ESPCI ParisTech-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire ondes et acoustique (LOA), Université Paris Diderot - Paris 7 (UPD7)-ESPCI ParisTech-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Institut Langevin - Ondes et Images (UMR7587) (IL), Sorbonne Université (SU)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Paris (UP)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Ondes et Acoustique (UMR 7587) (LOA), Université Paris Diderot - Paris 7 (UPD7)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], Physics, Coupling, Acoustics and Ultrasonics, business.industry, Acoustics, Operator (physics), [PHYS.MECA.SOLID]Physics [physics]/Mechanics [physics]/Mechanics of the solides [physics.class-ph], [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], Quality (physics), Arts and Humanities (miscellaneous), Nondestructive testing, [PHYS.MECA.SOLID]Physics [physics]/Mechanics [physics]/Solid mechanics [physics.class-ph], [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Loudspeaker, Structural health monitoring, business, ComputingMilieux_MISCELLANEOUS, Excitation, Audio frequency
Abstract: Generation of elastic waves is a major issue in nondestructive testing. Structural health monitoring of a thin element can be achieved through the analysis of its resonance spectrum. A time reversal mirror (TRM) operating in the audible frequency range (1-10 kHz) is used to remotely excite thin resonant elastic elements. The generation of elastic waves is studied with respect to the geometry of the TRM. It is observed that the quality of focusing only weakly depends on the number of loudspeakers (LS) in the TRM. When the air/plate coupling is at its maximum, the energetic efficiency of the TRM is estimated to be about 0.02%. The TRM is shown to efficiently and selectively excite a small structure embedded in a complex environment such as a hollow cylinder. Finally, the results are discussed in light of the DORT method (French acronym for "decomposition of the time reversal operator"). In particular, the optimal LS placement and emission signals in this configuration to excite individual eigenmodes of a plate is determined.
Published: 2019
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41. Depth Migration of Seismovolcanic Tremor Sources Below the Klyuchevskoy Volcanic Group (Kamchatka) Determined From a Network‐Based Analysis

Author: J. de Rosny, Jean Soubestre, Evgenii Gordeev, D. V. Droznin, N. M. Shapiro, Léonard Seydoux, Sergey Senyukov, S. Ya. Droznina, Instituto Volcanológico de Canarias (INVOLCAN), INVOLCAN, Institut des Sciences de la Terre (ISTerre), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Institut Langevin - Ondes et Images (UMR7587) (IL), Sorbonne Université (SU)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Paris (UP)-Centre National de la Recherche Scientifique (CNRS), Kamchatka Branch of the Geophysical Survey RAS, Institute of Volcanology and Seismology of the RAS, Far Eastern Branch of the Russian Academy of Sciences (FEB RAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: geography, geography.geographical_feature_category, 010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Covariance matrix, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, 010502 geochemistry & geophysics, 01 natural sciences, Spatial coherence, Geophysics, Volcano, [SDU]Sciences of the Universe [physics], 13. Climate action, Group (stratigraphy), [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, General Earth and Planetary Sciences, Geology, Seismology, 0105 earth and related environmental sciences
Abstract: International audience; We present a method for automatic location of dominant sources of seismovolcanic tremor in 3-D, based on the spatial coherence of the continuously recorded wavefield at a seismic network. We analyze 4.5 years of records from the seismic network at the Klyuchevskoy volcanic group in Kamchatka, Russia, when four volcanoes experienced tremor episodes. After enhancing the tremor signal with spectral whitening, we compute the daily cross-correlation functions related to the dominant tremor sources from the first eigenvector of the spectral covariance matrix and infer their daily positions in 3-D. We apply our technique to the tremors beneath Shiveluch, Klyuchevskoy, Tolbachik, and Kizimen volcanoes and observe the yearlong preeruptive volcanic tremor beneath Klyuchevskoy from deep to shallow partsof the plumbing system. This observation of deep volcanic tremor sources demonstrates that the cross-correlation-based method is a very powerful tool for volcano monitoring.
Published: 2019
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42. Subwavelength resonant dielectric nanoparticles with high refractive indices

Author: Mourad Sini, Pierre Millien, Alexander Dabrowski, Habib Ammari, Brian Fitzpatrick, Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Stadius Centre for Dynamical Systems, Signal Processing and Data Analytics, Partenaires INRAE, Institut Langevin - Ondes et Images (UMR7587) (IL), Sorbonne Université (SU)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Paris (UP)-Centre National de la Recherche Scientifique (CNRS), Johann Radon Institute for Computational and Applied Mathematics (RICAM), and Austrian Academy of Sciences (OeAW)
Subjects: [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], business.industry, High-refractive-index polymer, General Mathematics, 010102 general mathematics, General Engineering, Physics::Optics, high refractive index, Nanoparticle, Dielectric, asymptotic expansions, 01 natural sciences, subwavelength resonances, 010101 applied mathematics, dielectric nanoparticles, [MATH.MATH-MP]Mathematics [math]/Mathematical Physics [math-ph], MSC 2000: 35R30, 35C20, Optoelectronics, 0101 mathematics, business, Refractive index, Mathematics
Abstract: International audience; This paper aims at understanding the nature of the subwavelength resonant frequencies of dielectric particles with high refractive indices. It is proved that for an arbitrary shaped particle, these subwavelength resonant frequencies can be expressed in terms of the eigenvalues of the Newtonian potential associated with its shape. The enhancement of the scattered field at the resonant frequencies is shown. The hybridization of the subwavelength resonant frequencies of a dimer consisting of high refractive index dielectric nanoparticles is also characterized.
Published: 2019
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43. Combining 3D single molecule localization strategies for reproducible bioimaging

Author: Emmanuel Fort, Boris Vauzeilles, Nicolas Bourg, Christophe Leterrier, Sandrine Lévêque-Fort, Clément Cabriel, Pierre Jouchet, Guillaume Dupuis, Marie-Ange Badet-Denisot, Aurélie Baron, Institut des Sciences Moléculaires d'Orsay (ISMO), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Centre de Photonique Biomédicale (CPBM), Centre Laser Université Paris Sud, Institut de neurophysiopathologie (INP), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie des Substances Naturelles (ICSN), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), ANR-10-IDEX-0001,PSL,Paris Sciences et Lettres(2010), ANR-11-IDEX-0003,IPS,Idex Paris-Saclay(2011), European Project: 654148,H2020,H2020-INFRAIA-2014-2015,LASERLAB-EUROPE(2015), Centre Laser de l'Université Paris Sud (CLUPS), Université Paris-Sud - Paris 11 (UP11)-Université Paris-Sud - Paris 11 (UP11), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS), Institut Langevin - Ondes et Images, Université Paris Diderot - Paris 7 (UPD7)-ESPCI ParisTech-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), ANR-10-IDEX-0001-02/10-LABX-0024,WIFI,Institut Langevin : Ondes et Images, du Fondamental à l'Innovation(2010), and ANR-11-IDEX-0003-02/10-LABX-0032,LaSIPS,LABORATORY FOR SYSTEMS AND ENGINEERING OF PARIS SACLAY(2011)
Subjects: Single molecule localization, 0301 basic medicine, Point spread function, Fluorescence-lifetime imaging microscopy, Materials science, [SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology, Science, General Physics and Astronomy, 02 engineering and technology, Article, Fluorescence imaging, General Biochemistry, Genetics and Molecular Biology, law.invention, 03 medical and health sciences, Imaging, Three-Dimensional, Optics, law, Microscopy, Nanotechnology, Super-resolution microscopy, lcsh:Science, Anisotropy, 030304 developmental biology, 0303 health sciences, Multidisciplinary, business.industry, Resolution (electron density), General Chemistry, 021001 nanoscience & nanotechnology, Fluorescence, 3. Good health, 030104 developmental biology, Achromatic lens, lcsh:Q, 0210 nano-technology, business, Algorithms, 3d localization
Abstract: Here, we present a 3D localization-based super-resolution technique providing a slowly varying localization precision over a 1 μm range with precisions down to 15 nm. The axial localization is performed through a combination of point spread function (PSF) shaping and supercritical angle fluorescence (SAF), which yields absolute axial information. Using a dual-view scheme, the axial detection is decoupled from the lateral detection and optimized independently to provide a weakly anisotropic 3D resolution over the imaging range. This method can be readily implemented on most homemade PSF shaping setups and provides drift-free, tilt-insensitive and achromatic results. Its insensitivity to these unavoidable experimental biases is especially adapted for multicolor 3D super-resolution microscopy, as we demonstrate by imaging cell cytoskeleton, living bacteria membranes and axon periodic submembrane scaffolds. We further illustrate the interest of the technique for biological multicolor imaging over a several-μm range by direct merging of multiple acquisitions at different depths., 3D single molecule localization microscopy suffers from several experimental biases that degrade the resolution or localization precision. Here the authors present a dual-view detection scheme combining supercritical angle fluorescence and astigmatic imaging to obtain precise and unbiased 3D super resolution images.
Published: 2019
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44. Terahertz and Visible Probing of Particles Suspended in Air

Author: Julien de Rosny, Herve Sik, Clotilde Prophete, Rémi Carminati, Emmanuel Kling, Institut Langevin - Ondes et Images (UMR7587) (IL), Sorbonne Université (SU)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Paris (UP)-Centre National de la Recherche Scientifique (CNRS), SAFRAN Electronics & Defense, and SAGEM
Subjects: Radiation, Materials science, Laser diode, Spectrometer, business.industry, Scattering, Terahertz radiation, Attenuation, Mie scattering, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, law.invention, 010309 optics, Wavelength, Optics, law, 0103 physical sciences, Electrical and Electronic Engineering, 0210 nano-technology, business, Refractive index, ComputingMilieux_MISCELLANEOUS, [PHYS.COND.CM-MSQHE]Physics [physics]/Condensed Matter [cond-mat]/Mesoscopic Systems and Quantum Hall Effect [cond-mat.mes-hall]
Abstract: The attenuation of air suspended particles is measured with a terahertz (THz) time-domain spectrometer. Simultaneously, the attenuation at a wavelength of 650 nm is probed with a laser diode. On the one hand, this dual measurement allows a direct assessment of the visibility evolution in the THz range compared to the visible range. On the other hand, this setup provides an estimation of the scattering strength and the density of particles. Using the Mie theory, the method is successfully applied to experimentally characterize the refractive index of sand grains and glass beads. The refractive indexes of sand grains and glass beads, average over the acquisitions, are 1.67 and 2.54, respectively. The estimation of the scattering properties of sand grains is crucial to evaluate the performance of THz systems to image through brownout clouds that are created by helicopter rotors when landing in arid areas.
Published: 2019
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45. Infrared phase imaging using complex scattering media

Author: Pascal Berto, Anwesh Bhattacharya, Ignacio Izeddin, Gilles Tessier, Valentina Krachmalnicoff, Yannick De Wilde, Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)
Subjects: 010302 applied physics, Wavefront, Materials science, Opacity, business.industry, Infrared, Scattering, Infrared imaging, Phase (waves), Physics::Optics, Context (language use), 01 natural sciences, 010309 optics, Speckle pattern, Optics, Phase imaging, Complex media, 0103 physical sciences, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Speckle imaging, Surface scattering, business, Wavefront sensing, Broadband imaging
Abstract: International audience; Infrared imaging finds numerous applications in airborne measurements, structural monitoring, medical diagnostics, and spectroscopy. Long wave infrared (LWIR) radiation (λ = 8-14 µm) enables self-illuminated thermal imaging, and can uniquely identify different chemical species. The investigation of thermal emission control using plasmonic antenna devices, 1 and the study of tunable free-form planar optics 2 has motivated our development of a novel high-resolution thermal imaging technique. Speckle imaging has been successfully used to image optical intensity or phase through complex inhomogeneous scattering media-particularly at visible wavelengths, 3 and recently in the infrared. 4 Single-shot high-resolution images of the scattered light capture sufficient information to reconstruct images through opaque media and around corners with diffraction-limited resolution. In this context, we have developed a high-resolution broadband speckle imaging setup in the LWIR for phase reconstruction, using a thin scattering medium in front of an uncooled microbolometric camera. Our method utilizes the large angular memory effect of a thin scattering medium. Local phase gradients within the incoming beam produce distorted speckle images after scattering by the scatterer's surface. Local translation shifts between the speckle patterns are estimated by a fast diffeomorphic image registration algorithm to obtain a phase gradient map. Integrating this gradient map in 2-D finally yields the wavefront profile. We demonstrate infrared phase image reconstruction using our broadband LWIR speckle imaging methodology, which promises future applications in imaging through visually opaque objects like semiconductor circuits, solid-state nanoelectronics, and infrared optical components, for defect monitoring.
Published: 2021
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46. Probing thermal radiation of single or a small number of plasmonic nano-antennas

Author: Riad Haïdar, Valentina Krachmalnicoff, Yannick De Wilde, Patrick Bouchon, Loubnan Abou Hamdan, Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Université Paris sciences et lettres (PSL), DOTA, ONERA, Université Paris Saclay [Châtillon], and ONERA-Université Paris-Saclay
Subjects: Materials science, Infrared, business.industry, Nanophotonics, Thermal fluctuations, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, law.invention, 010309 optics, Thermal radiation, law, 0103 physical sciences, Thermal, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Optoelectronics, Scanning tunneling microscope, Antenna (radio), [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, 0210 nano-technology, business, Plasmon, ComputingMilieux_MISCELLANEOUS
Abstract: The electromagnetic modes of a sub-wavelength sized antenna can be excited both optically and through thermal fluctuations. When dealing with individual or a small number of nano-antennas, highly sensitive techniques, such as thermal radiation scanning tunneling microscopy, and infrared spatial modulation spectroscopy, are required in order to extract the very weak emitted thermal radiation. Using these techniques, we have been able to characterize the thermal emission of a single pair of sub-λ metal-insulator-metal antennas separated by a nanometric gap. It is found that the various hybrid modes of a single antenna pair can be simultaneously excited by thermal fluctuations, an essentially incoherent process arising from fluctuating thermal currents. The effect of hybrid plasmonic modes on the resonant behavior of the considered antenna system may guide future efforts for realizing tunable optical and thermal structures made up of a small number of antennas, for various applications.
Published: 2021
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47. Image Transmission Through a Dynamically Perturbed Multimode Fiber by Deep Learning

Author: Yaron Bromberg, Sebastien M. Popoff, Shachar Resisi, Université Paris sciences et lettres (PSL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Centre National de la Recherche Scientifique (CNRS), Institut Langevin - Ondes et Images (UMR7587) (IL), Sorbonne Université (SU)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Paris (UP)-Centre National de la Recherche Scientifique (CNRS), ANR-16-CE25-0008,MOLOTOF,Multiplexage Multimode de la Lumière pour les Télécommunications Optiques Fibrées(2016), ANR-10-LABX-0024,WIFI,Institut Langevin : Ondes et Images, du Fondamental à l'Innovation(2010), and ANR-10-IDEX-0001,PSL,Paris Sciences et Lettres(2010)
Subjects: Materials science, Physics::Optics, 02 engineering and technology, Iterative reconstruction, 01 natural sciences, multimode fiber, Image (mathematics), 010309 optics, Speckle pattern, Optics, 0103 physical sciences, [PHYS]Physics [physics], [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Multi-mode optical fiber, business.industry, Deep learning, imaging, deep learning, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Transmission (telecommunications), Artificial intelligence, 0210 nano-technology, business
Abstract: International audience; When multimode optical fibers are perturbed, the data that is transmitted through them is scrambled. This presents a major difficulty for many possible applications, such as multimode fiber based telecommunication and endoscopy. To overcome this challenge, a deep learning approach that generalizes over mechanical perturbations is presented. Using this approach, successful reconstruction of the input images from intensity-only measurements of speckle patterns at the output of a 1.5 m-long randomly perturbed multimode fiber is demonstrated. The model's success is explained by hidden correlations in the speckle of random fiber conformations.
Published: 2021

48. Epigenetic rewriting at centromeric DNA repeats leads to increased chromatin accessibility and chromosomal instability

Author: Decombe, Sheldon, Loll, François, Caccianini, Laura, Affannoukoué, Kévin, Izeddin, Ignacio, Mozziconacci, Julien, Escudé, Christophe, Lopes, Judith, Structure et Instabilité des Génomes (STRING), Muséum national d'Histoire naturelle (MNHN)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Physico-Chimie Curie [Institut Curie] (PCC), Institut Curie [Paris]-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), HAL-SU, Gestionnaire, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)
Subjects: Jumonji Domain-Containing Histone Demethylases, [SDV.MHEP] Life Sciences [q-bio]/Human health and pathology, Research, Centromere, DNA, QH426-470, Chromatin, Histone methylation, Epigenesis, Genetic, Chromosomal instability, Heterochromatin, Genetics, Humans, Epigenetics, [SDV.MHEP]Life Sciences [q-bio]/Human health and pathology
Abstract: Background Centromeric regions of human chromosomes contain large numbers of tandemly repeated α-satellite sequences. These sequences are covered with constitutive heterochromatin which is enriched in trimethylation of histone H3 on lysine 9 (H3K9me3). Although well studied using artificial chromosomes and global perturbations, the contribution of this epigenetic mark to chromatin structure and genome stability remains poorly known in a more natural context. Results Using transcriptional activator-like effectors (TALEs) fused to a histone lysine demethylase (KDM4B), we were able to reduce the level of H3K9me3 on the α-satellites repeats of human chromosome 7. We show that the removal of H3K9me3 affects chromatin structure by increasing the accessibility of DNA repeats to the TALE protein. Tethering TALE-demethylase to centromeric repeats impairs the recruitment of HP1α and proteins of Chromosomal Passenger Complex (CPC) on this specific centromere without affecting CENP-A loading. Finally, the epigenetic re-writing by the TALE-KDM4B affects specifically the stability of chromosome 7 upon mitosis, highlighting the importance of H3K9me3 in centromere integrity and chromosome stability, mediated by the recruitment of HP1α and the CPC. Conclusion Our cellular model allows to demonstrate the direct role of pericentromeric H3K9me3 epigenetic mark on centromere integrity and function in a natural context and opens interesting possibilities for further studies regarding the role of the H3K9me3 mark. Supplementary Information The online version contains supplementary material available at 10.1186/s13072-021-00410-x.
Published: 2021
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49. Stability for finite element discretization of some elliptic inverse parameter problems from internal data -- application to elastography

Author: Bretin, Elie, Millien, Pierre, Seppecher, Laurent, Université Claude Bernard Lyon 1 (UCBL), Université de Lyon, Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA), Institut Camille Jordan [Villeurbanne] (ICJ), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Modélisation mathématique, calcul scientifique (MMCS), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), Centre National de la Recherche Scientifique (CNRS), Institut Langevin - Ondes et Images (UMR7587) (IL), Sorbonne Université (SU)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Paris (UP)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Mathematics Subject Classification (MSC2000). 65J22, 65M60 Inverse problems, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, 65N21, Numerical Analysis (math.NA), [MATH.MATH-FA]Mathematics [math]/Functional Analysis [math.FA], Functional Analysis (math.FA), Linear Elastography, Mathematics - Functional Analysis, Reverse Weak Formulation, 35R30, Finite Element Method, FOS: Mathematics, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], Inf-Sup constant, Mathematics - Numerical Analysis, [MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA]
Abstract: In this article, we provide stability estimates for the finite element discretization of a class of inverse parameter problems of the form $-\nabla\cdot(\mu S) = \g f$ in a domain $\Omega$ of $\R^d$. Here $\mu$ is the unknown parameter to recover, the matrix valued function $S$ and the vector valued distribution $\g f$ are known. As uniqueness is not guaranteed in general for this problem, we prove a Lipschitz-type stability estimate in an hyperplane of $L^2(\Omega)$. This stability is obtained through an adaptation of the so-called discrete \emph{inf-sup} constant or LBB constant to a large class of first-order differential operators. We then provide a simple and original discretization based on hexagonal finite element that satisfies the discrete stability condition and shows corresponding numerical reconstructions. The obtained algebraic inversion method is efficient as it does not require any iterative solving of the forward problem and is very general as it does not require any smoothness hypothesis for the data nor any additional information at the boundary.
Published: 2021

50. Dynamic full-field optical coherence tomography allows live imaging of retinal pigment epithelium stress model

Author: Kassandra Groux, Anna Verschueren, Céline Nanteau, Marilou Clémençon, Mathias Fink, José-Alain Sahel, Claude Boccara, Michel Paques, Sacha Reichman, Kate Grieve, Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts (CHNO), Centre d'investigation clinique Quinze-Vingts [CHNO] (CIC1423 - CIC QUINZE-VINGTS), Institut Hospitalo-Universitaire FOReSIGHT, Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts (CHNO)-Sorbonne Université (SU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts (CHNO)-Sorbonne Université (SU), Institut de la Vision, Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Fondation Ophtalmologique Adolphe de Rotschild, University of Pittsburgh School of Medicine, Pennsylvania Commonwealth System of Higher Education (PCSHE), and Grieve, Kate
Subjects: Macular Degeneration, Swine, [SDV.BC.BC] Life Sciences [q-bio]/Cellular Biology/Subcellular Processes [q-bio.SC], Medicine (miscellaneous), Animals, Humans, [SDV.BC.BC]Life Sciences [q-bio]/Cellular Biology/Subcellular Processes [q-bio.SC], Retinal Pigment Epithelium, Fluorescein Angiography, General Agricultural and Biological Sciences, General Biochemistry, Genetics and Molecular Biology, Tomography, Optical Coherence, Mitochondria
Abstract: Retinal degenerative diseases lead to the blindness of millions of people around the world. In case of age-related macular degeneration (AMD), the atrophy of retinal pigment epithelium (RPE) precedes neural dystrophy. But as crucial as understanding both healthy and pathological RPE cell physiology is for those diseases, no current technique allows subcellular in vivo or in vitro live observation of this critical cell layer. To fill this gap, we propose dynamic full-field OCT (D-FFOCT) as a candidate for live observation of in vitro RPE phenotype. In this way, we monitored primary porcine and human stem cell-derived RPE cells in stress model conditions by performing scratch assays. In this study, we quantified wound healing parameters on the stressed RPE, and observed different cell phenotypes, displayed by the D-FFOCT signal. In order to decipher the subcellular contributions to these dynamic profiles, we performed immunohistochemistry to identify which organelles generate the signal and found mitochondria to be the main contributor to D-FFOCT contrast. Altogether, D-FFOCT appears to be an innovative method to follow degenerative disease evolution and could be an appreciated method in the future for live patient diagnostics and to direct treatment choice.
Published: 2021
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