Optical device having thin film formed over optical waveguide
US6400881B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 20, 1998 |
| Grant date | Jun 4, 2002 |
| Priority date | — |
| Expiry date | Jul 20, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F2203/055
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical device has a substrate, a polarization beam splitter, first and second pairs of optical waveguides, a transducer and a thin film. The polarization beam splitter is formed on the substrate and has input and output sides. The first and second pairs of optical waveguides are formed on the substrate to guide polarized optical signals. The first pair of optical waveguides meets at the input side of the polarization beam splitter, and the second pair of optical waveguides meets at the output side of the polarization beam splitter. The transducer is formed of a comb-tooth electrode on the substrate to excite a surface acoustic wave on the substrate and rotate the polarization of the optical signal. The thin film covers a portion of each waveguide of either the first or second pairs of optical waveguides. The thin film may be formed of silicon dioxide or indium dioxide, either with a metal oxide optionally added thereto. The speed of sound in the thin film is less than that in the substrate. The thin film is formed of a material which is transparent to the optical signal. The thin film has a refractive index smaller than that of the optical waveguides.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.