Bistable spatial light modulators (BSLMs) composed of a liquid crystal (LC) cell and a photoconductor, which have two-dimensional optical nonlinear functions (hysteresis, differential gain and limiting), are useful for optical computing and image processing. This paper reports optical parallel logic operations using a new type of compact transmission-mode BSLM which has the advantages of spatial uniformity and a simple device structure. The BSLM consists of a guest-host (GH) LC layer which contains nematic LC and dichroic dye molecules twisted by 90° between two alignment layers, a Bi12GeO20 (BGO) crystal layer with a thickness of 1.7 mm, which is conductive under blue light illumination, and transparent indium tin oxide electrodes. The bistable properties of the BSLM can be used for various aspects of nonlinear image processing such as logic operations, intensity level thresholding and memory.
|Number of pages
|Proceedings of SPIE - The International Society for Optical Engineering
|Published - 1990
|1990 International Topical Meeting on Optical Computing - OC '90 - Kobe, Jpn
Duration: 1990 Apr 8 → 1990 Apr 12