Abstract

We present the design and characterization of a spatial light modulator (SLM) comprising a ferroelectric liquid crystal (FLC) light modulating layer atop a silicon CMOS VLSI circuit. Our SLM consists of two electrically addressable arrays on the same integrated circuit die. The first, a 1 × 128 linear array with 20-μm center-to-center pixel spacing, used shift register addressing, while the second, a 64 × 64 square array with 60-μm pitch, used static random access memory (SRAM) addressing. In both cases, latching and buffering of the cells states with CMOS circuitry has led to the capability of writing a complete frame in less than the switching time of the FLC material used and has eliminated the need for refresh. The resulting SLM could be addressed at frame rates of up to 4.5 kHz and gave single-element intensity contrast ratios of 12:1. Our light modulator fabrication procedure is independent of the nature of the circuitry on the silicon die. Thus the entire functional repertoire of silicon technology is available for incorporation into high performance SLMs based on FLC materials.

© 1989 Optical Society of America