Beam steering using a new class of fast, high-polarization ferroelectric liquid crystals

Period of Performance: 07/09/2003 - 07/09/2004

$99.6K

Phase 1 SBIR

Recipient Firm

Displaytech, Inc.
2200 Central Avenue
Boulder, CO 80301
Principal Investigator

Abstract

It has long been known that optical phased array (OPA) beam steering can be performed by liquid crystal devices, yet available liquid crystals are either too slow for many applications (1 ms - 100's of milliseconds) or they are incapable of producing the necessary range of analog phase modulation. Developments in a new class of ferroelectric liquid crystals (FLCs) during the last couple of years have the potential to overcome these limitations, enabling OPA beam steering devices with speeds in excess of 5 kHz. OPAs consist of two-dimensional arrays of individual FLC phase modulators, they can be made by placing a layer of liquid crystal on the top surface of a specially designed VLSI circuit. The VLSI surface is divided into an array of individual electrodes, one per modulator. However, optimal drive voltages for the new FLC far exceed the capabilities of normal CMOS VLSI circuitry. We have devised a charge-controlled drive scheme to overcome this problem, allowing the new FLCs to be driven by CMOS-compatible voltages. Using the new FLCs and drive scheme, we propose to develop OPA fine steering mirrors capable of the speed and accuracy required for free space optical communications systems. Successful development of the proposed technology will benefit commercial users by enabling higher bandwidth free-space communications between points lacking optical fiber links, by improving the quality of information that can be obtained from LADAR systems, and by making available a novel programmable optics component technology that should be of use in diverse applications such as optical disk drives, holographic data storage, and optical switching. If it can be made cheaply enough, it could also offer a flexible alternative to scanners currently used for warehouse inventory control and supermarket scanners which use conventional opto-mechanical mechanisms.