Liquid Crystal Cells for Blazed Grating Steering Devices

摘要

Two types of non-mechanical liquid crystal laser beam steering devices were developed. The first is a prismatic refractive device with a smectic liquid crystal wedge as a passive light deflector and twisted nematic flat cell as an optical switch. The prismatic device has constant deflected beam intensity for all deflection angles (several degrees) and works in the (1-10) ms range of the response times. The other type is based on electrically controlled cholesteric diffraction gratings. The cholesteric grating is a phase grating capable of both Bragg and Raman-Nath diffraction and two modes of operation: simple electric switching between non-diffractive and diffractive regimes; continuous beam steering up to 20 degrees. This devices works in the (10-100) ms range of the response times.