Semiconductor laser device
US4176325A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 19, 1977 |
| Grant date | Nov 27, 1979 |
| Priority date | — |
| Expiry date | Oct 19, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/2275
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A semiconductor laser device capable of emitting highly collimated beams, especially of a narrow beam divergence, is disclosed. A striped hetero-junction is formed on a predetermined semiconductor substrate by a first semiconductor layer (refractive index: n.sub.1, band gap: Eg.sub.1, thickness: d), a second semiconductor layer (n.sub.2) and a third semiconductor layer (n.sub.3), and the hetero-junction is sandwiched between portions of a fourth semiconductor layer (n.sub.4, Eg.sub.4) into a buried structure. At this time, the various materials are selected to follow the relations of d.ltoreq..lambda. (where .lambda. denotes the oscillation wavelength of the semiconductor laser), n.sub.2, n.sub.3 <n.sub.4 <n.sub.1, and Eg.sub.1 <Eg.sub.4, and the effective refractive index of the first semiconductor layer (n.sub.1eq) is made smaller than n.sub.4.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.