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8 results on '"K. Fedus"'

2. Image formation and applications to third order nonlinear optical measurement techniques

Author

Coulombier, Q., Sergent, M., Trolès, J., Canat, G., Vasseur, O., Bourdon, P., Cathelinaud, M., Zhang, X.H., M. Cathelinaud, M. Cathelinaud, Nazabal, Virginie, F. Charpentier, F. Charpentier, J. L. Adam, J., K. Fedus, K. Fedus, G. Boudebs, G. Boudebs, M. Chauvet, M. Chauvet, G. Fanjou, G. Fanjou, K. P. Huy, K., T. Billeton, T Billeton, S. P. Gorza, S., W. D. Shen, W., Manzani, Danilo, Napoli, Mariana, Ribeiro, Sidney J.L., de Araújo, Cid, Besse, Valentin, Leblond, Hervé, Boudebs, Georges, Fedus, K., Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Moléculaires de Marseille (ISM2), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institute of Chemistry, São Paulo State University, Departamento de Fisica, Universidade Federal de Pernambuco, Universidade Federal de Pernambuco [Recife] (UFPE), Laboratoire de Photonique d'Angers (LPHIA), Université d'Angers (UA), Propriétés Optiques des Matériaux et Applications (POMA), Université d'Angers (UA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Institut de Chimie du CNRS (INC), and Centre National de la Recherche Scientifique (CNRS)-Université d'Angers (UA)

Subjects
Diffraction, Physics, Image formation, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Helmholtz equation, business.industry, Acoustics, Nonlinear optics, 01 natural sciences, Signal, 010309 optics, Optics, Simple (abstract algebra), 0103 physical sciences, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Sensitivity (control systems), 010306 general physics, business, Diffraction grating, ComputingMilieux_MISCELLANEOUS
Abstract

We perform third order nonlinear optical characterizations using I-scan or Z-scan techniques inside a 4-f system. Simulation is performed based on Helmholtz equation to provide simple expressions relating the signal to the phase shift (in different wave-mixing configurations). Optimization of the measurement is performed.

Published
2012
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3. Second-order susceptibility χ(2) in Si waveguides

Author

Alessandro Pitanti, B. Dierre, Lorenzo Pavesi, E. Borga, A. Yeremian, Mher Ghulinyan, Paolo Bettotti, K. Fedus, R. Pierobon, Massimo Cazzanelli, G. Pucker, and Federica Bianco

Subjects
Silicon photonics, Materials science, Silicon, business.industry, Hybrid silicon laser, Analytical chemistry, chemistry.chemical_element, Nonlinear optics, Nanosecond, Waveguide (optics), Overlayer, chemistry, Femtosecond, Optoelectronics, business
Abstract

Tensile strained-silicon waveguides were produced by LPCVD (780 °C) by depositing a 150 nm-thick Si 3 N 4 overlayer. Nonlinear nanosecond and femtosecond transmission experiments indicated the presence of a significant χ(2) in the bulk silicon.

Published
2011
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4. Properties and limitations of chalcogenide films

Author

M. Cathelinaud, M. Cathelinaud, primary, V. Nazabal, V. Nazabal, additional, F. Charpentier, F. Charpentier, additional, J. L. Adam, J. L. Adam, additional, K. Fedus, K. Fedus, additional, G. Boudebs, G. Boudebs, additional, M. Chauvet, M. Chauvet, additional, G. Fanjou, G. Fanjou, additional, K. P. Huy, K. P Huy, additional, T. Billeton, T Billeton, additional, S. P. Gorza, S. P Gorza, additional, and W. D. Shen, W. D Shen, additional

Published
2010
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5. Excitation mechanism and thermal emission quenching of Tb ions in silicon rich silicon oxide thin films grown by plasma-enhanced chemical vapour deposition—Do we need silicon nanoclusters?

Author

K. Fedus, P. R. J. Wilson, G. Zatryb, Jacek Wojcik, Artur Podhorodecki, Peter Mascher, J. Wang, Jan Misiewicz, L W Golacki, and Wojciech M. Jadwisienczak

Subjects
Materials science, Photoluminescence, Silicon, chemistry, Analytical chemistry, General Physics and Astronomy, chemistry.chemical_element, Cathodoluminescence, Chemical vapor deposition, Thin film, Fourier transform infrared spectroscopy, Silicon oxide, Rutherford backscattering spectrometry
Abstract

In this work, we will discuss the excitation and emission properties of Tb ions in a Silicon Rich Silicon Oxide (SRSO) matrix obtained at different technological conditions. By means of electron cyclotron resonance plasma-enhanced chemical vapour deposition, undoped and doped SRSO films have been obtained with different Si content (33, 35, 39, 50 at. %) and were annealed at different temperatures (600, 900, 1100 °C). The samples were characterized optically and structurally using photoluminescence (PL), PL excitation, time resolved PL, absorption, cathodoluminescence, temperature dependent PL, Rutherford backscattering spectrometry, Fourier transform infrared spectroscopy and positron annihilation lifetime spectroscopy. Based on the obtained results, we discuss how the matrix modifications influence excitation and emission properties of Tb ions.

Published
2014
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6. Two-dimensional micro-Raman mapping of stress and strain distributions in strained silicon waveguides

Author

Massimo Cazzanelli, Mher Ghulinyan, R. Pierobon, K. Fedus, Francesco Enrichi, Federica Bianco, Georg Pucker, and Lorenzo Pavesi

Subjects
inorganic chemicals, Silicon, Materials science, Raman mapping, chemistry.chemical_element, law.invention, stress, symbols.namesake, chemistry.chemical_compound, strain, Optics, law, Materials Chemistry, Electrical and Electronic Engineering, business.industry, Scattering, Stress–strain curve, technology, industry, and agriculture, Strained silicon, waveguides, Condensed Matter Physics, Cladding (fiber optics), Electronic, Optical and Magnetic Materials, Raman mapping, Silicon, stress, strain, waveguides, Silicon nitride, chemistry, symbols, Optoelectronics, business, Raman spectroscopy, Waveguide
Abstract

Micro-Raman scattering experiments were performed on strained silicon waveguides designed for nonlinear optical experiments. Thin stressing silicon nitride (Si3N4 or SiNx) cladding layers, deposited on a light-guiding silicon core layer, strain silicon to enable χ(2), the second-order nonlinear susceptibility. Different deposition treatments allow varying the applied stress. The resulting strained waveguides are investigated by micro-Raman confocal spectroscopy performed on the waveguide facet. By modelling the measured Raman shifts, the local stress and strain are extracted. Thus, two-dimensional maps of the stress distribution as a function of the SiNx deposition parameters are drawn. A comparison of different samples allows underlying the non-uniformity of resulting strain.

Published
2012
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7. Photo-stability of pulsed laser deposited Ge(x)As(y)Se(100-x-y) amorphous thin films.

Author

Němec P, Zhang S, Nazabal V, Fedus K, Boudebs G, Moreac A, Cathelinaud M, and Zhang XH

Abstract

Quest for photo-stable amorphous thin films in ternary Ge(x)As(y)Se(100-x-y) chalcogenide system is reported. Studied layers were fabricated using pulsed laser deposition technique. Scanning electron microscope with energy dispersive X-ray analyzer, Raman scattering spectroscopy, transmittance measurements, variable angle spectroscopic ellipsometry, and non-linear imaging technique with phase object inside the 4f imaging system were employed to characterize prepared thin films. Their photo-stability/photo-induced phenomena in as-deposited and relaxed states were also investigated, respectively. In linear regime, we found intrinsically photo-stable relaxed layers within Ge(20)As(20)Se(60) composition. This composition presents also the highest optical damage threshold under non-linear optical conditions.

Published
2010
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8. Linear optical characterization of transparent thin films by the Z-scan technique.

Author

Boudebs G and Fedus K

Abstract

We report experimental characterization of a very small rectangular phase shift (<0.3 rad) obtained from the far-field diffraction patterns using a closed aperture Z-scan technique. The numerical simulations as well as the experimental results reveal a peak-valley configuration in the far-field normalized transmittance, allowing us to determine the sign of the dephasing. The conditions necessary to obtain useful Z-scan traces are discussed. We provide simple linear expressions relating the measured signal to the phase shift. A very good agreement between calculated and experimental Z-scan profiles validates our approach. We show that a very well known nonlinear characterization technique can be extended for linear optical parameter estimation (as refractive index or thickness).

Published
2009
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