The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 26, 1998
Filed:
Jan. 03, 1997
Kenichi Ono, Tokyo, JP;
Hitoshi Tada, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A semiconductor laser device includes a structure in which a first conductivity AlGaInP first cladding layer, an active layer, a second conductivity type AlGaInP second cladding layer, a second conductivity type AlGaInP intermediate layer, and a second conductivity type AlGaInP third cladding layer are successively epitaxially grown on a first conductivity type GaAs semiconductor substrate. The intermediate layer is within a profile of light produced in the active layer and includes AlGaInP layers having a band gap energy smaller than the band gap energy of the second cladding layer and the third cladding layer and larger than the band gap energy of the active layer. The intermediate layer has a multi-layer structure in which (Al.sub.x Ga.sub.1-x)InP layers (0.ltoreq.x.ltoreq.0.2) and (Al.sub.x Ga.sub.1-x)InP layers (0.5.ltoreq.x.ltoreq.1) are alternatingly laminated. By adding a small amount of Al to the intermediate layer, the band gap energy of the intermediate layer is broadened to control absorption of light emitted from the active layer and an increase in the threshold current of laser oscillation is suppressed. Since the intermediate layer has a multi-layer structure, a semiconductor laser device with sufficient etch stopping effect during etching of an off (100) substrate is realized.