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:
May. 17, 1988
Filed:
Oct. 24, 1986
Ken Hamada, Toyonaka, JP;
Kunio Itoh, Uji, JP;
Masahiro Kume, Takatsuki, JP;
Takao Shibutani, Takatsuki, JP;
Hirokazu Shimizu, Suita, JP;
Matsushita Electric Industrial Co., Ltd., Kadoma, JP;
Abstract
A BTRS (buried Twin-Ridge Substrate) structure laser, wherein an oblong protrusion (10) is provided on a substrate (1) of a first conductivity type and two ridges (9, 9) divided by a groove (31) therebetween are provided on a second layer (2) of a second conductivity type, and thereon plural layers (3, 4, 5, 6) including an active layer (4) are provided is improved to have longer service life such that: the protrusion (10) is shortened so as to have its both ends apart inside cavity facet of the substrate (1), or further by width of each ridge (9, 9) is narrowed at both ends thereof thereby forming narrowed end parts (9', 9'), so that excessive current injection to the active layer near the cavity facet is eliminated.