Semiconductor saturable absorber mirror
US6538298B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 2001 |
| Grant date | Mar 25, 2003 |
| Priority date | — |
| Expiry date | Dec 10, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/3523
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A “low field enhancement” (LFR) semiconductor saturable absorber device design in which the structure is changed such that it has a resonant condition. Consequently, the field strength is substantially higher in the spacer layer, resulting in a smaller saturation fluence and in a higher modulation depth. However, the field in the spacer layer is still lower than the free space field or only moderately enhanced compared to the field in the free space. According to one embodiment, the absorber device is a Semiconductor Saturable Absorber Mirror (SESAM) device. In contrast with SESAMs according to the state of the art, a structure including the absorber and being placed on top of a Bragg reflector is provided, which essentially fulfills a resonance condition whereby a standing electromagnetic wave is present in the structure. In other words, the design is such that the field intensity reaches a local maximum in the vicinity of the device surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.