Apparatus and method for controlling extinction ratio in a liquid crystal polarization controller optical switch
US7245328B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 17, 2002 |
| Grant date | Jul 17, 2007 |
| Priority date | — |
| Expiry date | Jun 17, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/133382
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A polarization controller includes: a liquid crystal cell; a mechanism for determining a compensation voltage; and a voltage driving circuit for applying the compensation voltage to the liquid crystal cell, where the application of the compensation voltage optimizes an extinction ratio of the liquid crystal cell. The controller controls the extinction ratio using an applied voltage to compensate for temperature changes, liquid crystal cell gap variations, and other errors of the liquid crystal cell. This controller is aimed at liquid crystal devices used in a wide ambient temperature range and is also useful to compensate for the fabrication errors of the liquid crystal switches.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.