Low divergence laser
US5197077A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 1992 |
| Grant date | Mar 23, 1993 |
| Priority date | — |
| Expiry date | Feb 28, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S2301/18
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A semiconductor ridge diode laser, capable of providing a single mode, high power laser output having a low divergence in the far field, comprised of a plurality of semiconductor layers having three quantum wells therein. The layers of the diode laser are doped such that the PN junction occurs in or near the center quantum well. A pair of graded index layers surround each quantum well to provide transverse optical confinement. In addition to linear grading of the index of refraction in the graded index layers, stepped changes in the index of refracton or other profile types changes such as a parabolic grading may also be used. The P-side of the diode laser is etched to form a ridge with which electrical contact may be maintained to confine the optical signals laterally. Such semiconductor laser structures with the depth of the PN junction an appropriate transverse distance from the bottom surface of the ridge such that current supplied may spread have an increase in emission spot size in the near field and a decrease in the far field divergence in both the transverse and the lateral direction. The spacing and the width of the quantum wells must be such that the emission spot size i…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.