Search

The design of versatile, high-capacity 1 2 N photonic switches based on Ferroelectric Liquid Crystal (FLC) beam deflectors were investigated. Results obtained for a 1 2 14 switch prototype are presented. The extension to a larger capacity switch (1 2 32) is also investigated, with possible improvements in optical bandwidth, and inter-channel crosstalk.

The recent development of wavelength division multiplexing requires novel transparent optical switches with moderate reconfiguration rates (typically the ms) for management and safety requirements at the optical -wavelength- level. One important fonction in such an optical switch is beam steering in the infrared 1.55 μm region. For that purpose, we propose to design a ferroelectric liquid crystal spatial light modulator (FLC SLM) acting as a programmable diffraction grating. Futhermore, a large-tilt angle FLC is used to make the device insensitive to the polarisation of the input wavefront. Prior to the realisation of the optical swich, we present here an experimental characterisation of the FLC beam deflector.

We present a general-purpose three-dimensional interconnection network that models various parallel operations between two data planes. This volume interconnection system exhibits reconfigurable capabilities because of parallel and externally weighted interconnection modules, called nodes. We propose a generic optical implementation based on the cascading of two planar hologram arrays, coupled with a bistable optically addressed spatial light modulator. The role of this component is discussed in terms of energy regeneration and spatial cross-talk limitation. As an example, a binary matrix–matrix multiplier is implemented that uses a ferroelectric liquid-crystal light valve.

We address free-space optical interconnections based on cascaded multifacet holographic elements, including an intermediate regeneration of the optical signals. Particular attention is paid to digital hologram encoding in the case of highly interconnected planes. Degrees of freedom selected in the reconstruction plane are used for satisfying both holographic-encoding and signal constraints. An iterative Fourier-transform algorithm is chosen because of its ability to incorporate constraint considerations.

The capacity of optically addressed bistable ferroelectric liquid-crystal spatial light modulators to be used for recording binary computer-generated holograms is experimentally demonstrated. The recording and reconstruction of cell- and point-oriented holograms are presented.