Abstract

Liquid crystal-on-silicon (LCOS) spatial light modulators (SLMs) have many applications, including microdisplays, optical beamsteering, and optical information processing. In these devices, a thin liquid-crystal layer is sandwiched between a silicon substrate with VLSI circuitry and a piece of glass coated with a transparent conductive electrode. Voltages applied to metal mirrors on the silicon back-plane result in a local optic-axis rotation of chiral smectic liquid crystals such as the surface-stabilized ferroelectric liquid crystal (FLC), the electroclinic SmA* liquid crystal, or the distorted-helix FLC. A uniform polarized optical beam incident upon the device from the liquid crystal (LC) side is reflected from the mirrors, resulting in a spatial modulation of the input light’s optical polarization. A polarizer placed at the output of the SLM can convert this polarization modulation to intensity or phase modulation.

© 1995 IEEE