Jean-Louis de Bougrenet de la Tocnaye

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We propose to induce a two-dimensional (2D) periodic modulation structure into a planar Grandjean cholesteric liquid crystal (CLC) to demonstrate the intrinsic 2D photonic crystal properties of such materials. The structure combines a thin transmission grating and a Bragg reflective grating. One advantage of using CLC is the intrinsic high quality Bragg(More)
A tunable millimetre-wave generator using optical phase modulators with no DC bias and no filters (neither RF nor optical filters) is proposed in this paper. A 60 GHz RF signal is optically generated by multiplying the frequency of an input RF signal at 7.5 GHz by a factor of 8. The electrical suppression ratio is around 70 dB as shown by simulations.
A photonic circuit design for implementing frequency 8-tupling and 24-tupling is proposed. The front- and back-end of the circuit comprises 4×4 MMI couplers enclosing an array of four pairs of phase modulators and 2×2 MMI couplers. The proposed design for frequency multiplication requires no optical or electrical filters, the operation is not limited to(More)
A new formulation of a multiplex filter for filtering-based optical processors, based on the VanderLugt architecture, is presented. The multireference binary phase-only filter (MBPOF), optimized by regions of support (ROS), constitutes a formal rewriting of some multiplex or composite filters including optimization functions, such as the distribution(More)
Annular linear diffractive axicons are optical devices providing chromatic imaging over an extended depth of focus when illuminated by a white light. To improve their low radiometric performance, multiple annular linear diffractive axicons (MALDAs) have been introduced. Their chromatic properties are well known and constrained by dispersion laws. A first(More)
By using soluble fullerene derivative [60]PCBM, we improved photorefractive efficiency in polymer-liquid crystal composites in comparison to previous works on similar materials. We show the effect of polymer network results in resolution and bandwidth improvements compared to pure liquid crystals. This is explained by the introduction of a charge trapping(More)
In this paper, we discuss various technical options to implement 3D dual-view systems, from four frames generated by two triggered or non-triggered 3D projectors. Such a technique offers 3D free-viewpoint capabilities for two viewers. We compare two different technical implementations based on transmissive video projection and reflective silver screen,(More)
We propose an optical apparatus enabling the measurement of spherical power, cylindrical power, and optical center coordinates of ophthalmic lenses. The main advantage of this new focimeter is to provide a full bidimensional mapping of the characteristics of ophthalmic glasses. This is made possible thanks to the use of a large-area and high-resolution(More)
We report the design and fabrication of a chirped switchable reflective grating (CSRG) recorded in a holographic polymer-dispersed liquid-crystal material. This CSRG is a spatial wavelength-selective flattener in a free-space dynamic gain equalizer for use in wavelength-division multiplexing (WDM) networks. Prelimenary experimental results show that this(More)
PURPOSE We investigated the impact of target properties on vertical fusion amplitude (VFA) using a 3D display platform; the performance of the subjects allowed us to assess how central and peripheral retina regions interact during the fusion process. MATERIAL AND METHODS Fourteen subjects were involved in the test. VFA was recorded by varying the viewing(More)
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