ac liquid-crystal light valve

Abstract

An ac-operated liquid-crystal light valve has been constructed and operated. The multilayer structure, consisting of a photoconductor, light-absorbing layer, dielectric mirror, and liquid crystal, is capable of efficiently modulating a high-intensity light beam with a comparatively weak light source. The dielectric mirror and absorbing layer provide high reflectance and optical isolation without the use of a metal mosaic reflector. The use of ac and insulated electrodes promises long lifetime. The light valve is applicable to television projection display and optical data processing.

Photoaddressing Of High Speed Liquid Crystal Spatial Light Modulators

“…Optical addressing of spatial light modulators is advantageous because it is a direct addressing techniquea camera, frame grabber, and computer are not required to write a data pattern onto the SLM. Existing photoaddressed liquid crystal SLMs are limited to millisecond response times [1][2][3][4][5]. In this paper we present two methods for fabricating SLMs with microsecond response times by photoaddressing ferroelectric liquid crystals with hydrogenated amorphous silicon.…”

“…Since the switching speeds of most of these devices is limited by the modulator to moderate values (milliseconds), the response -time demands placed upon the photosensors have been modest. The Hughes liquid crystal light valve, for example, uses a CdS photosensor [1,2]. In this device a nematic liquid crystal is switched with a 30 msec cycle time.…”

Using dichromated gelatin as a diffractive optical storage medium and illustration of multiple applications

“…The light is collimated using a 50-mm diam, 250-mmfocal-length lens. After deflection by the polarizing beamsplitter to the Hughes liquid-crystal light valve ͑LCLV͒, 19 which is a spatial light modulator 20 having pixel size of about 50 m and serves as a transducer to encode the incoherent input scene onto the coherent laser light, the object beam is reflected off the dielectric mirror of the LCLV, passes through the beamsplitter, and is Fourier transformed by a 750-mm-focal-length lens. The plateholder in the near Fourier plane is mounted on two MicroControl micropositioners.…”

Grayscale-Memory Spatial Light Modulator with Polymer-Dispersed Phase-Transition Liquid Crystal

“…V0= VB Zpc+ZLCll[ZLcl , (1) where VB is obtained from the electrooptic property of the PDPTLC film shown in Fig. 4.…”