Liquid Crystal Spatial Light Modulators for Optical Image Preprocessing

Abstract

Spatial light modulators (SLM) are considered as the main elements of optical data processing systems. Liquid crystal SLMs (LCSLM) having high performance parameters are normally used in optical systems as image transducers and optical filters. The value of LCSLM for optical data processing is increased by combining image transducing and image preprocessing functions in the same sample. Such a combination improves the flexibility and productivity of optical data processing methods, and simplifies optical setup. Among realized preprocessing functions of LCSLM are the edge enhancement, the selection of nonstationary objects, the optical analog of lock-in-amplifier, image subtraction, and spatial selection of the image details corresponding to their intensity. Most of mentioned preprocessing functions and new features like IR-sensitivity, IR-modulation are primarily realized in LC SLM at P.N.Lebedev Institute. The physical mechanisms for these opportunities are discussed together with possible improvements in parameters and features. Recently observed new electro-optical effects in ferroelectric liquid crystals are reported as ones giving new opportunity to combine image preprocessing and fast response.