Method of improving selectivity in a tunable waveguide filter
US6665474B2 · kind B2 · utility
2Cited by
12References
11Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Feb 22, 2002 |
| Grant date | Dec 16, 2003 |
| Priority date | — |
| Expiry date | Feb 22, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S3/2308
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A tunable waveguide filter, formed from two waveguides, has an improved selectivity. The filter is tuned by passing a current through the filter. One of the waveguides is a semi-active waveguide. The increased absorption of charge carriers that occurs when current is injected into the semi-active waveguide is compensated by gain enhancement in the waveguide, because the material used for the semi-active waveguide is selected to provide an appropriate amount of gain. Therefore, the gain compensates for the losses that arise from free carrier absorption when the tuning current is applied to the filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.