Ivan E. Morichev

Spatial light modulators based on chalcogenide glass photoconductor - liquid crystal structure operating in pulse regime

Main characteristics of the SLMs based on the chalcogenide glass photoconductor--liquid crystal structure under different operating conditions and SLM applications as input and real-time holographic devices in the JTC and as integrating/threshold elements in optical neural networks are discussed.

Influence of photoconductor parameters on characteristics of spatial-light-modulators based on photoconductor-liquid crystal structures

The Spatial Light Modulator (SLM) based on photoconductor - liquid crystal structure is one of the key components in optical data processing systems. The performance characteristics of the SLMs often determine the main properties of the input devices and the optical data processing system as a whole including the speed of data processing, volume of input information. Frequently the effectiveness of a data processing system is not determined by the input device speed but by the device resolution and availability of gray scale of input iniages.

Response rate of optically controlled space-time light modulators based on a bismuth-silicate-nematic-liquid-crystal structure

This paper presents an experimental study of the possibility of enhancing the response rate of a photoconductor-nematic-liquid-crystal structure. The contribution introduced by the inertia of the individual layers is analyzed for various structures and under various conditions. It is proven that, when the read-out is done with radiation from the mid-IR region, it is impossible in principle to achieve response rates higher than several hertz. This applies to all space-time light modulators of the given type, since the response rate depends not on the properties of the semiconductor but on the thickness of the liquid-crystal layer, which in turn is entirely determined by the wavelength of the readout radiation.

Optically addressed spatial light modulators based on the photoconductor: liquid crystal structures for real-time optical applications

Main characteristics of the Optically Addressed Spatial Light Modulators based on the chalcogenide glass photoconductor--nematic liquid crystal and the a-Si:H-- ferroelectric liquid crystal structures, advantages of both types of the devices and possible applications are discussed.

Optically addressed spatial light modulators for coherent optical data processing applications

Main characteristics of the Optically Addressed SLMs based on the chalcogenide glass photoconductor--nematic liquid crystal and the a-Si:H--ferroelectric liquid crystal structures, advantages of both types of the SLMs and possible applications are discussed.

Liquid Crystal Modulators with improved laser damage resistance

Experimental results have been given on laser-damage resistance of the liquid crystal modulator with longitudinal operating electrical field. It was shown that laser-damage resistance of the modulator is limited by the ITO transparent electrodes and equals 2.5 - 2.9 J/cm2 at 1.06 nm, (tau) equals 15 ns. To improve this parameter we proposed an liquid crystal structure controlled by a transverse electric field in which the ITO electrodes are removed out of the zone intense laser radiation. The main characteristics of this mode liquid crystal modulator are discussed.

Speed of response analysis of optically controlled transparent photoconductor liquid crystal plates in a holographic correlator

Speed of response is a major characteristic of light space and time modulators (LSM) in coherent optical data processing, notably in holographic correlators. The response of a photoconductor-liquid crystal (PCLC) modulator is a function of the delay in the electro- optical LC response, in the PC photoresponse, and the delay caused by the redistribution of charges in the PCLC structure. In the case of high resistance PCs the redistribution makes the decisive contribution to the response. The typical values of the PCLC structure time constant in the case of high resistance semiconductors amount to tens or hundreds of milliseconds while the delay in the photoresponse is measured in single numbers of milliseconds. With typical values of the control voltage the electro-optical response of usual LCs amounts to single digits of milliseconds while the relaxation time ranges from 10 to 20 milliseconds.