Optical switch having birefringent element
US4919522A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 25, 1988 |
| Grant date | Apr 24, 1990 |
| Priority date | — |
| Expiry date | Feb 25, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/31
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An electrically controlled optical switch employs an electro-optical crystal of the kind exhibiting birefringence in each of two different light paths when the crystal is disposed in orthogonally oriented electric fields, with each light path being sensitive to a different one of the two electric fields and each path having its own set of fast and slow axes. A crystal of bismuth germanium oxide has those properties. Electrodes are provided for separately establishing each of the two electric fields and control circuitry allows only one field at a time to be established. Polarizers are situated at opposite ends of the electro-optical crystal in alignment with each of the two paths. Adjacent one end of the crystal are disposed a beam splitter and a right angle prism. The prism is arranged to receive some of the light entering the beam splitter and reflect that light along one of the paths of the crystal while another portion of the entering light proceeds through the beam splitter into the other path of the crystal. The polarizers block the light in one path while enabling light to emerge from the other path.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.