Semiconductor laser
US4366568A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 18, 1980 |
| Grant date | Dec 28, 1982 |
| Priority date | — |
| Expiry date | Dec 18, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/223
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a semiconductor laser, an n-type first clad layer, an undoped active layer, and a p-type second clad layer are formed on an n-type semiconductor substrate by liquid phase sequential epitaxial growth. The second clad layer is photo-etched to form a stripe-shaped thicker part at the center and thinner parts on both sides thereof. Thereafter, an n-type isolation layer is further epitaxially formed, and a Zn impurity is diffused in a thinner part of the isolation layer in a stripe-shaped pattern at the position above the thicker part, thereby forming a p+-type conduction region in the central part of the thinner part of the n-type isolation layer. By forming the stripe-shaped ridge part in the clad layer, light lased in the active layer is effectively confined in a stripe-shaped part thereof which is underneath the ridge part. Therefore, a stable transverse mode of lasing results. By forming the thicker part, the n-type isolation layer, very closely above the thinner side parts of the active layer, injected current is effectively confined to the lasing region which is underneath the ridge part. Therefore, the threshold current is decreased.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.