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:
Jun. 18, 1996
Filed:
Jan. 24, 1995
NEC Corporation, Tokyo, JP;
Abstract
A semiconductor laser having improved reliability. The laser contains an AlGaInP first cladding layer of a first conductivity type, an AlGaInP second cladding layer of a second conductivity type that forms a mesa stripe, an active layer made of an undoped GaInP layer, an undoped AlGaInP layer, or a quantum well layer of an undoped GaInP sublayer and an undoped AlGaInP sublayer. The laser further contains a burying layer made of an Al.sub.x In.sub.1-x P or (Al.sub.y Ga.sub.1-y).sub.x In.sub.1-x P layer, which is placed at both sides of the mesa stripe to bury the stripe. The burying layer is larger in energy band gap than the active layer and smaller in refractive index than the second cladding layer. The burying layer has first regions that are contacted with and extend along respective side faces of the mesa stripe. An Al composition x of the first regions is set so that the first regions are lattice-matched to GaAs. The burying layer has second regions that are joined with respective bottom ends of the first regions and extend along the active layer. An Al composition x of the second regions is set so that the second regions are lattice-matched or are not lattice-matched to GaAs.