Multi-pass optical spectrum analyzer having a polarization-dependent tunable filter
US6819429B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 6, 2001 |
| Grant date | Nov 16, 2004 |
| Priority date | — |
| Expiry date | Mar 22, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B5/3025
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A polarization independent optical spectrum analyzer comprises an inherently polarization sensitive angle-tuned filter element and polarization-maintaining multi-pass optics for directing a light beam to and fro through the tunable filter element while maintaining its linear state of polarization. The optical spectrum analyzer comprises such a tunable optical filter in combination with a polarization control unit for decomposing a light beam for analysis into first and second beams having mutually orthogonal states of polarization (SOPs) and then adjusting one or both SOPs so that they are parallel to each other and to one of the principal axes of the angle-tuned filter which selects different wavelengths of the first and second light beams. The first and second light beams are passed through the filter repeatedly by multi-pass polarization-maintaining optics.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.