Abstract: We describe a LCOS (liquid crystal on silicon) telecommunications light beam routing device, the device comprising: an optical input; a plurality of optical outputs; a LCOS spatial light modulator (SLM) in an optical path between said input and said output, for displaying a kinoform; a data processor, coupled to said SLM, configured to provide kinoform data for displaying said kinoform on said SLM; wherein said kinoform data defines a kinoform which routes a beam from said optical input to a selected said optical output; wherein said data processor is configured to input routing data defining said selected optical output and to calculate said kinoform data for routing said beam responsive to said routing data; and wherein said data processor is configured to calculate said kinoform data by: determining an initial phase pattern for said kinoform; calculating a replay field of said phase pattern; modifying an amplitude component of said replay field to represent a target replay field for said beam routing, reta

Abstract: This invention relates to methods and apparatus for routing light beams in telecommunications devices using holographic techniques, in particular by displaying kinoforms on Liquid Crystal on Silicon devices. At least one optical input to receives an input beam. A plurality of optical outputs and a spatial light modulator (SLM) on an optical path between said optical input and said optical outputs are provided, and a driver for said SLM to display a kinoform on said SLM diffracts said input beam into an output beam comprising a plurality of diffraction orders, wherein a routed one of said diffraction orders is directed to at least one selected said optical output; said apparatus is configured to modify a wavefront of said output beam to reduce a coupling of said output beam into said selected optical output; and said kinoform is adapted to compensate for said wavefront modification to compensate for said reduced coupling.

Abstract: This invention relates to methods and apparatus for routing light beams in telecommunications devices using holographic techniques, in particular by displaying kinoforms on LCOS (Liquid Crystal on Silicon) devices.

Abstract: The invention relates to optical beam steering. There is described an optical beam steering apparatus, comprising: a splitter arranged to split an optical beam into at least a first part having a first polarization and a second part having a second polarization, said first and second polarizations being substantially mutually orthogonal; a first liquid crystal device region arranged to receive said first part and to have director orientation substantially aligned to said first polarization; and a second liquid crystal device region arranged to receive said second part and to have director orientation substantially aligned to said second polarization.

Abstract: The invention provides a process for producing a layer of a semiconductor material, wherein the process comprises: a) disposing on a substrate: i) a plurality of particles of a semiconductor material, ii) a binder, wherein the binder is a molecular compound comprising at least one metal atom or metalloid atom, and iii) a solvent; and b) removing the solvent. The invention also provides a layer of semiconductor material obtainable by this process. In a preferred embodiment, the particles of a semiconductor material comprise mesoporous particles of the semiconductor material or mesoporous single crystals of the semiconductor material.

Abstract: We describe a LCOS (liquid crystal on silicon) telecommunications light beam routing device, the device comprising: an optical input; a plurality of optical outputs; a LCOS spatial light modulator (SLM) in an optical path between said input and said output, for displaying a kinoform; a data processor, coupled to said SLM, configured to provide kinoform data for displaying said kinoform on said SLM; wherein said kinoform data defines a kinoform which routes a beam from said optical input to a selected said optical output; wherein said data processor is configured to input routing data defining said selected optical output and to calculate said kinoform data for routing said beam responsive to said routing data; and wherein said data processor is configured to calculate said kinoform data by: determining an initial phase pattern for said kinoform; calculating a replay field of said phase pattern; modifying an amplitude component of said replay field to represent a target replay field for said beam routing, reta

Abstract: The invention provides an optoelectronic device comprising a photoactive region, which photoactive region comprises: an n-type region comprising at least one n-type layer; a p-type region comprising at least one p-type layer; and, disposed between the n-type region and the p-type region: a layer of a perovskite semiconductor without open porosity. The perovskite semiconductor is generally light-absorbing. In some embodiments, disposed between the n-type region and the p-type region is: (i) a first layer which comprises a scaffold material, which is typically porous, and a perovskite semiconductor, which is typically disposed in pores of the scaffold material; and (ii) a capping layer disposed on said first layer, which capping layer is said layer of a perovskite semiconductor without open porosity, wherein the perovskite semiconductor in the capping layer is in contact with the perovskite semiconductor in the first layer.

Abstract: This invention relates to methods and apparatus for routing light beams in telecommunications devices using holographic techniques, in particular by displaying kinoforms on LCOS (Liquid Crystal on Silicon) devices.

Abstract: A method of displaying a video image comprises receiving sequential image frames at a processor. Each image frame is processed to obtain a kinoform. A programmable diffractive element such as an SLM represents the sequence of kinoforms allowing reproduction of the image using a suitable illumination beam.

Abstract: A method of displaying a video image comprises receiving sequential image frames at a processor. Each image frame is processed to obtain a kinoform. A programmable diffractive element such as an SLM represents the sequence of kinoforms allowing reproduction of the image using a suitable illumination beam.

Abstract: A method of displaying a video image comprises receiving sequential image frames at a processor. Each image frame is processed to obtain a kinoform. A programmable diffractive element such as an SLM represents the sequence of kinoforms allowing reproduction of the image using a suitable illumination beam.

Abstract: This invention generally relates to an optical beam steering apparatus and a method of manufacturing an optical beam steering apparatus, and more particularly to an optical add drop multiplexer (OADM) such as a reconfigurable OADM (ROADM) comprising the optical beam steering apparatus. In one embodiment, the apparatus comprises a slab and a plurality of optical elements in or on a first surface of said slab, the plurality of optical elements including at least one liquid crystal on silicon element, the apparatus being arranged such that at least one optical beam can propagate freely in the slab from one of said plurality of optical elements to another one of said plurality of optical elements via a reflection from a second surface of the optical beam steering apparatus.

Abstract: The invention relates to optical beam steering. There is described an optical beam steering apparatus, comprising: a splitter arranged to split an optical beam into at least a first part having a first polarisation and a second part having a second polarisation, said first and second polarisations being substantially mutually orthogonal; a first liquid crystal device region arranged to receive said first part and to have director orientation substantially aligned to said first polarisation; and a second liquid crystal device region arranged to receive said second part and to have director orientation substantially aligned to said second polarisation.

Abstract: A liquid crystal device including a layer of liquid crystal material, and provided on one side of the liquid crystal material layer an array of conductors for generating electric fields therebetween to change the molecular orientation of pixel portions of the layer of liquid crystal material, wherein each pixel portion of the liquid crystal material layer is associated with a respective group of conductors distributed over the respective pixel area for the application of voltages across distances smaller than the pixel dimensions, wherein the conductors and the spacing therebetween within each group are sufficiently small with respect to the thickness of the liquid crystal material layer that each group can be used to generate an electric field that induces through at least a portion of the thickness of the liquid crystal material layer a different molecular orientation pattern that is substantially uniform across the whole area of the respective pixel portion.

Abstract: In an active semiconductor backplane for a liquid crystal spatial light modulator, spacers (25) which are distributed over the backplane extend above an array of electrical and/or electronic elements and comprise at least two layers essentially of the same material and occuring in the same order as is found in at least one of the electrical or electronic elements, such as an NMOS transistor (52). The latter is formed from a stack of layers on a silicon substrate (51) comprising polysilicon (56), continuous silicon oxide (57) modified to include gate oxide GOX (55), metallic gate electrode (59), continuous silicon oxide (58) and a metallic drain electrode (60) which is coupled to a spaced mirror electrode over the layer (58). Likewise, spacer (25) comprises the layers (57 and 58) with metallic (67, 68) deposited simultaneously with electrodes (59, 60). The foot of layer (57) is differently modified to include field oxide layer (69) and polysilicon layers thin oxide (71).

Abstract: The present invention provides a liquid crystal cell that is bistable in operation and comprises a ferroelectric compound having a smectic C phase, arranged between alignment layers of polyamide or polyester. Said compound has the general formula wherein R represents an alkyl group having from 1 to 10 carbon atoms or the group each R? represents an alkyl group having from 1 to 4 carbon atoms, T is X represents an alkyl or halogen-substituted alkyl group having at least one chiral centre, Y represents a fluorine atom, m has a value of 0, 1 or 2, p has a value of 2, 3 or 4 and n has a value of 10, 11 or 12.

Abstract: An optical switch uses a polarisation insensitive spatial light modulator operating by a double pass through a liquid crystal cell. The switch includes two such modulators in a cross bar arrangement. Different embodiments employing techniques for reducing cross talk are described.

Abstract: A method of displaying a video image comprises receiving sequential image frames at a processor. Each image frame is processed to obtain a kinoform. A programmable diffractive element such as an SLM represents the sequence of kinoforns allowing reproduction of the image using a suitable illumination beam.

Abstract: A packet switch having plural input sectors and output sectors, each input sector being arranged to hold at least one queue per output sector, each output sector having plural output ports and being arranged to hold at least one queue per output port wherein the input sectors are connected to the output sectors via links configured to afford speed-up of data transfer, wherein the links comprise a set of links, and wherein the switch has means for cyclically connecting different subsets of the set of links between the input sectors and the output sectors, and means responsive to statistical variations in traffic applied to input ports of said input sectors to vary the set of links.

Abstract: A display (50) with enhanced image contrast contains an image-producing component (60) and a set of shutter strips (80). The image-producing component, typically a flat-panel device, has multiple imaging lines that provide light to produce an image. Each shutter strip is situated in front of one or more associated imaging lines. By appropriately switching the shutter strips between light-absorptive and light-transmissive states, the image contrast is enhanced. The shutter strips are typically implemented with a liquid-crystal display structure. The switching of the shutter strips is typically performed with a control component (52/76) which utilizes light to control the shutter switching and which is synchronized to signals (90 or/and 100) that control the imaging lines.