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. 24, 1996
Filed:
Aug. 28, 1995
Applicant:
Inventor:
Tetsuya Yagi, Itami, JP;
Assignee:
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01S / ;
U.S. Cl.
CPC ...
372 46 ; 372 45 ;
Abstract
A superlattice layer is introduced in the ridge stripe structure of a buried ridge type semiconductor laser. This superlattice layer captures and redirects the propagation of a dislocation which occurs due to a shearing stress created in the crystalline structure during either an epitaxial growth or a cooling process following the epitaxial growth. This superlative layer eliminates the possibility of a through dislocation penetrating the laser active region under the ridge stripe structure so that optical loss along a waveguide can be avoided. Consequently, a semiconductor laser with a long lifetime and superior characteristics is obtained.