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:
Sep. 26, 2006
Filed:
Apr. 25, 2003
Tsuyoshi Nagatake, Kanagawa, JP;
Shoji Hirata, Kanagawa, JP;
Tsuyoshi Nagatake, Kanagawa, JP;
Shoji Hirata, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
A semiconductor laser device is one of AlGaInAs semiconductor laser devices, and has a multi-layer structure with a n-GaAs substrate on which a n-AlGaAs buffer layer, a n-AlGaAs clad layer, active layer portion, p-AlGaAs clad layer and p-GaAs cap layer are formed. The active layer portion is configured as a multi-layer structure including (AlGa)InAs light guide layer, AlGaAs active layer and (AlGa)InAs light guide layer. By using the AlGaInAs layer to which In is added is used as the light guide layers, the active layer is under compressive strain. Accordingly, the lattice constant of the active layer at the laser emitting edge becomes smaller due to a force from the adjacent light guide layers. The band gap energy of the active layer near the laser emitting edge becomes larger than the inside of laser device, thereby forming the window structure.