Liquid crystal cell window

Abstract

Abstract An optical time delay unit for use in an optical phased array beam-steering system includes a switchable polarization rotator in conjunction with Brewster plates and mirrors to form electrically-selectable optical paths of different lengths. The switchable polarization rotator is aligned with the optical beam and is responsive to a control signal for varying the polarization of light passing therethrough. The Brewster plates receive the light passing through the first polarization rotator and are transmissive to a first polarization and reflective of a second. The transmissive and reflective paths are of different lengths, and are recombined at a second Brewster plate. The original polarization may be restored by a second polarization rotator. A plurality of time delay units may be cascaded to permit selection from among many paths of various lengths. In a preferred embodiment, the polarization rotators include liquid crystal cells having nematic phase molecules. Optically-transparent electrodes are formed on the cell windows by an ion implantation process. A planar phased array beamforming system comprises a plurality of time delay units, illustratively arranged in a 2-by-2 configuration, wherein each unit is illuminated by a corresponding sector of a single light beam.

Inventors

• 👤 Daniel P. Resler

Bibliographic Details