Variable optical attenuator
US7379226B2 · kind B2 · utility
1Cited by
2References
6Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 30, 2007 |
| Grant date | May 27, 2008 |
| Priority date | — |
| Expiry date | Jul 30, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F2203/48
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A variable optical attenuator comprising a separation/combination birefringent element, fixed polarization rotation means, a convex lens, variable polarization rotation means, and a mirror which are arranged in that order. The fixed polarization rotation means has a compensation film Faraday element placed in a cylindrical permanent magnet, and the variable polarization rotation means has a base film Faraday element that is placed outside the cylindrical permanent magnet, and an electromagnet applying a variable magnetic field thereto. Thereby, both the Faraday elements are magnetized in directions different from each other.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.