Polarization independent tunable acousto-optical filter and the method of the same
US6404536B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 8, 2001 |
| Grant date | Jun 11, 2002 |
| Priority date | — |
| Expiry date | Mar 8, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F2203/06
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The present invention pertains to a polarization independent tunable acousto-optical filter and the corresponding method. The filter diffracts an input light beam into a first input light beam unaffected by acoustic waves and a second input light beam affected by acoustic waves. A polarization beam displacer/combiner is employed to separate the input light beam into two orthogonal beams. Several polarized rotators are used to rotate the polarization of light by 90 degrees. An acousto-optical device makes the polarization of light with a particular wavelength rotate by 90 degrees. The two beams are then properly combined to form orthogonal beams. The filtering method has nothing to do with the polarization of the incident light. The filter has such advantages as a high extinction ratio, a small volume and a lower cost.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.