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:
Jan. 31, 1995
Filed:
Mar. 31, 1993
Hiroki Naito, Suita, JP;
Masahiro Kume, Ohtsu, JP;
Hideyuki Sugiura, Takatsuki, JP;
Toru Takayama, Nara, JP;
Kunio Itoh, Uji, JP;
Issei Ohta, Fujiidera, JP;
Hirokazu Shimizu, Suita, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A semiconductor laser device suitable as a light source for an optical disk may be operated at a low operating current with low noise for the 780 nm band. The device comprises: a certain conduction type Ga.sub.1-Y1 Al.sub.Y1 As first light guide layer, a Ga.sub.1-Y2 Al.sub.Y2 As second light guide layer of said certain conduction type, or an In.sub.0.5 Ga.sub.0.5 P or an In.sub.0.5 (GaAl).sub.0.5 P or an InGaAsP second light guide layer, successively formed one upon another at least in one side of the principal plane of an active layer; an opposite conduction type Ga.sub.1-Z Al.sub.Z As current blocking layer formed on the second light guide layer and provided with a stripe-like window; and a Ga.sub.1-Y3 Al.sub.Y3 As cladding layer of the same conduction type as the light guide layers formed on the stripe-like window. The relations of Z>Y3>Y2 and Y1>Y2 define the AlAs mole fractions.