Liquid crystal cell window
US4882235A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 2, 1988 |
| Grant date | Nov 21, 1989 |
| Priority date | — |
| Expiry date | Mar 2, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12681
- WIPO fieldOptics
- WIPO sectorInstruments
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 config…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.