Optical device having modified transmission characteristics by localized thermal treatment
US6442311B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 9, 1999 |
| Grant date | Aug 27, 2002 |
| Priority date | — |
| Expiry date | Jul 9, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B2006/12171
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Transmission characteristics of an optical device 200, fabricated from multiple layers 16, 27, 28 of silica-based glass on a silicon substrate 26, are modified by localized thermal treatment. The beam 501 of a carbon-dioxide (CO2) laser 510 is used to selectively soften the core and/or cladding material of a waveguide structure during or after the fabrication process. In one application, softening relieves the strain developed between the waveguide structure and the silicon substrate and substantially reduces or eliminates birefringence. In a second application, the CO2 laser is operated at another power level in order to modify the index of refraction. Changes in the index of refraction change the speed of light through a waveguide thereby changing the phase shift associated with the waveguide. In a third application, the CO2 laser is operated at yet another power level to increase the transmission loss of the waveguide. In all of the embodiments, heat treatment is substantially faster and/or less expensive than known techniques for modifying the transmission characteristics of an optical device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.