Optical wavelength filter
US4273411A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 24, 1980 |
| Grant date | Jun 16, 1981 |
| Priority date | — |
| Expiry date | Jan 24, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F2203/055
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical TE.revreaction.TM mode converter, using highly birefringent materials such as lithium niobate, is wavelength sensitive and, as such, can be used as a wavelength filter. However, to extract the filtered (i.e., the mode converted) signal, a separate, high quality polarization selective element is required. This application discloses means for eliminating the need for a separate polarization sensing element by using mode conversion as a means for spatially separating the filtered signal. The filter comprises a pair of mismatched waveguides (11, 12), and phase matching means (14, 15) for producing selective coupling between TE mode wave energy in one of the guides and TM mode wave energy on the other guide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.