Tunable filter for optical add/drop module
US6909549B1 · kind B1 · utility
Inventors
Key dates
| Filing date | Mar 6, 2003 |
| Grant date | Jun 21, 2005 |
| Priority date | — |
| Expiry date | Jun 21, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/2766
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A tunable filter includes a polarizing beam splitter and a half-wave plate that produce two equally polarized beams from an arbitrarily polarized input light. The polarized beams are directed toward a tunable component that consists of an optical substrate coated with a filter and a reflective element on its back and front surface, respectively. The pass and stop beams emerging from the tunable component are retro-reflected by roof structures and passed again through the filter. As a result of this combination of components, the filter's performance is not dependent on polarization and the filter's output channels are not shifted or deviated by tuning.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.