Liquid crystal modulator and polarization diversity optics for optical communications
US6801310B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 2, 2002 |
| Grant date | Oct 5, 2004 |
| Priority date | — |
| Expiry date | Nov 5, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/2793
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
For systems which disperse individual wavelength components of a DWDM beam into an array of converging beams, the individual wavelength signals are modified for blocking, equalization or other purposes by reflective liquid crystal cells. Thus modulated or modified components are then recombined by the system into an output beam, as by reverse passage through the system. Controlled full extinction or linear attenuation may be introduced by converging asymmetrical beams of separate polarization components for each wavelength into superposed relation on zero twist nematic crystal cells which are voltage controlled so as to retard for extinction of greater than 40 dB or to transform the state of polarization to a selected angle for attenuation. Polarization sensitive elements in the return paths of the reflected beams then filter the rejected components.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.