256X256 LIQUID-CRYSTAL-ON-SILICON SPATIAL LIGHT-MODULATOR

A 256 x 256 pixel spatial light modulator (SLM) is designed and constr ucted by the use of liquid-crystal-on-silicon technology. The device i s a binary electrically addressed SLM with a measured zero-order contr ast ratio of 70:1 and an imaged contrast ratio of 10:1. The pixel pitc h is 21.6 mum, which gives an array size of 5.53 mm. The electronic lo ad time is 43 mus, and the 10%-90% switching time of the liquid crysta l is approximately 75-80 ps at room temperature, which implies a maxim um frame rate of approximately 8.3 kHz. We discuss the design trade-of fs that are intrinsic to this type of device and describe how the prim ary application for the device in an optical correlator influenced the final design.