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:
Aug. 10, 1993
Filed:
Oct. 18, 1991
Applicant:
Inventors:
Assignee:
Rohm Co., Ltd., Kyoto, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01S / ;
U.S. Cl.
CPC ...
372 46 ;
Abstract
A semiconductor laser device comprises: an active layer; a lower clad layer provided below the active layer; an upper clad layer provided above the active layer; and a current blocking layer, provided above the upper clad layer, for limiting an active region of the active layer in a direction along a width to make the active region of a striped form which has a wide portion and a narrow portion. According to the device, coherence of an oscillated laser beam is reduced, thereby to decrease a feedback induced noise when used for a pickup of an optical information recording/reproducing apparatus.