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Terahertz (THz) technology has attracted great attention in the past few decades for its unique applications in various fields, including spectroscopy, noninvasive detection, wireless communications, and imaging. In parallel to this, the practical, fast, and broadband modulation of THz waves is becoming indispensable. Two‐dimensional (2D) materials exhibit unusual optical and electrical properties, which has prompted tremendous interest and significant advances in THz modulation. This review provides the recent progress in 2D materials‐based THz modulators, outlining the operating principles, including all‐optical, electro‐optic, magneto‐optic, and other exotic mechanisms. We focus on the recent advances in THz modulation by the designed photonic structures, such as heterostructure, metamaterial, capacitor, optical cavity, and waveguide integration. Lastly, we discussed the challenges and opportunities for 2D materials‐based THz modulators and presented our prospects for the future development.

We investigated emission properties of photonic structures with InAs/InGaAlAs/InP quantum dashes grown by molecular beam epitaxy on a distributed Bragg reflector. In high-spatial-resolution photoluminescence experiment, well-resolved sharp spectral lines are observed and single-photon emission is detected in the third telecommunication window characterized by very low multiphoton events probabilities. The photoluminescence spectra measured on simple photonic structures in the form of cylindrical mesas reveal significant intensity enhancement by a factor of 4 when compared to a planar sample. These results are supported by simulations of the electromagnetic field distribution, which show emission extraction efficiencies even above 18% for optimized designs. When combined with relatively simple and undemanding fabrication approach, it makes this kind of structures competitive with the existing solutions in that spectral range and prospective in the context of efficient and practical single-photon sources for fiber-based quantum networks applications.

In this article, a multifunctional and multiscale device which can realize the functions of the magnetic-controlled AND logical operation and detection based on the one-dimensional magnetized InSb photonic structure is proposed and theoretically investigated. Properly modulating the target resonant absorption peak by the external magnetic field, and employing the peak to determine the logical operation, the accurate AND logical operation is fulfilled. Since the target absorption peak holds a superior quality factor value, the designed structure can be considered for detecting the crucial physical quantities, magnetic field, and refractive index. Especially, owing to the magneto-optical effect, time-reversal symmetry and space-reversal symmetry are broken, and the nonreciprocity is generated, which further makes the logical operations and detection of the forward and backward scales can be simultaneously acquired. Numerical analysis gains the optimal sensitivity, the quality value and detection limit. For the detection of magnetic field, and refractive index are 3.13 × 1012 T−1, 9341, 8.4 × 10−5 T, and 1.13 × 1011 RIU−1, 10537, 5.6 × 10−4 RIU, respectively. Surpassing the conventional electromagnetic devices, the designed photonic structure in this work with the combination of magnetic-controlled AND logical operation and detection functions plays a significant constructive role in information communication and photonic computing.

International audience; Natural photonic structures have been extensively studied and have shown their interest as a source of inspiration for new bio-inspired devices in many areas. After these initial studies and characterization phases, we have now to reproduce these structures, mainly in inorganic materials, to exacerbate interesting effects or generate new ones. If we want to preserve the best of their multi-scale and more or less ordered structures, producing a molding seems more appropriate. Such prints can be achieved by physical or chemical means, the latter being a priori particularly suitable for three-dimensional structures.

We present our recent results on the fabrication of photonic devices such as single-mode and few-mode waveguides, Ycouplers as well as integrated interferometric sensor devices. The devices were created by means of a fabrication method based on maskless lithography, which allows for fabricating embedded integrated polymer elements on a scale of several square centimeters with a resolution down to one micron. We demonstrate the versatility of our approach by presenting first results on photonic structures created by maskless lithography. © 2016 SPIE. DFG/SFB/TRR 123

The planar orientation of Nematic Liquid crystal (NLC) molecules on the surface of (111) plane of silica photonic structure has been investigated. Nano voids of silica photonic crystal has been obtained by vertical deposition technique on indium tin oxide-coated substrate. NLC was infiltrated into the channels of voids in the photonic structures. Optical texture studies under with and without electric field were applied to investigate the NLC orientation. It is observed that NLC molecules in the nano voids of silica photonic structure exhibit an excellent planar alignment. This obtained hybrid composite structure on infiltration of NLC will be a promising candidate for electro optic applications.

In this report we present an investigation of the optical properties and band structure calculations for the photonic structures based on the functional materials- ferroelectrics. A theoretical approach to the optical properties of the 2D and 3D photonic crystals which yields further insight in the phenomenon of the reflection from different families of lattice planes in relation to the presence of photonic gaps or photonic bands. We calculate the photonic bands and optical properties of LiNbO3 based photonic crystals. Calculations of reflection and transmission spectra show the features correspond to the onset of diffraction, as well as to additional reflectance structures at large values of the angle of incidence., 10 pages, 4 figures, 1 table, This paper were presented at 21 st International Symposium on Applications of Ferroelectrics (ISAF ECAPD PFM 2012 Averio, Portugal) and accepted for publication in Ferroelectrics (2013)

It is shown that strong diffractions and related dual-beam splitting can be obtained at transmission through the nonsymmetric structures that represent two slabs of photonic crystal (PhC) separated by a single coupled-cavity type defect layer, while there are no grating-like corrugations at the interfaces. The basic operation regimes include unidirectional and bidirectional splitting that occur due to the dominant contribution of the first positive and first negative diffraction orders to the transmission, which is typically connected with different manifestations of the asymmetric transmission phenomenon. Being the main component of the resulting transmission mechanism, diffractions appear owing to the effect exerted by the defect layer that works like an embedded diffractive element. Two mechanisms can co-exist in one structure, which differ, among others, in that whether dispersion allows coupling of zero order to a wave propagating in the regular, i.e., defect-free PhC segments or not. The possibility of strong diffractions and efficient splitting related to it strongly depend on the dispersion properties of the Floquet-Bloch modes of the PhC. Existence of one of the studied transmission scenarios is not affected by location of the defect layer. Published by AIP Publishing.

International audience; This report presents the Apertureless Scanning Optical Near‐Field Microscope as a powerful tool for the characterization of modern optoelectronic and photonic components with sub‐wavelength resolution. We present an overview of the results we obtained in our laboratory over the past few years. By significant examples, it is shown that this specific probe microscopy allows for in situ local quantitative study of semiconductor lasers in operation, integrated optical waveguides produced by ion exchange (single channel or Y junction), and photonic structures.