New Liquid Crystal Devices for Adaptive Optics

摘要

The idea of using liquid crystal as adaptive optics components has been proposed by several authors. In recent years a vigorous research effort has been carried out, and it is still flourishing, in several countries. Mainly the research and experimental work has been concentrated in US, U.K. and Russia. There are several reasons why liquid crystal may represent a valid alternative to the traditional deformable mirror technology that has been used for the past two decades or so. The main attractiveness of LC is resides in the cost. Current deformable mirror technology has a range of price going from dollar2K to dollar15K per channel. LC technology promises to be at leas a couple of order of magnitude cheaper. Other reasons are connected with reliability, low power consumption and with a huge technological momentum based on a wide variety of industrial applications. In this paper I present some of the experimental results of a 5 years, on going, research effort at the Air Force Research Lab. Most of the work has been on the development of suitable devices with extremely high optical quality, individually addressable pixels, fast switching time. The bulk of the work has been concentrated in the arena of the untwisted nematic material. However new devices are now under development using dual-frequency nematic material and high tilt angle ferroelectric material.