Birefringence-free semiconductor waveguide
US5732179A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 30, 1995 |
| Grant date | Mar 24, 1998 |
| Priority date | — |
| Expiry date | Mar 30, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/3404
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A birefringence-free semiconductor waveguide comprising on a substrate a plurality of layers some of which are in tensile strain with respect to the substrate and others of which are in compressive strain. Birefringent-free behavior with respect to a guided light signal traveling in the waveguiding structure and possessing a photon energy lower than the bandgap of the constituent waveguide layers is obtained when birefringence introduced into the individual layers of the waveguiding structure by the strain is sufficient to compensate for the intrinsic geometric modal birefringence of the waveguiding structure that exists in the case where all layers are not strained. This is achieved through the introduction of a predetermined amount of tensile strain into one of more layers possessing a bandgap energy relatively close to the photon energy of the guided light and the introduction of a predetermined amount of compressive strain into one or more layers possessing a bandgap energy that is relatively further from the photon energy of the guided light signal. In this manner, waveguiding structures that are substantially free of modal birefringence may be obtained with partial or complet…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.