Hybrid surface emitting laser and detector
US4906839A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 30, 1988 |
| Grant date | Mar 6, 1990 |
| Priority date | — |
| Expiry date | Jun 30, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/0683
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The present invention is a combined surface emitting semiconductor laser and photodetector in a single housing with the photodetector positioned to detect light emitted from the surface emitting laser and reflected off of a medium. The surface emitting laser is mounted on the top surface of a chip which includes at least one set of two photodetectors for detecting a reflected beam. At least two photodetectors are used so that spacial variations in the reflected beam can be detected for focusing and tracking when the device is used in an optical head. Photodetectors are arranged to intersect a diffracted beam from a hologram lens used in an optical head. A rear emission photodetector for monitoring the power of the surface emitting laser is positioned so that it will not receive diffracted light which will interfere with its operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.