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. 15, 1990
Filed:
Sep. 29, 1989
Hidenori Kawanishi, Higashiosaka, JP;
Hiroshi Hayashi, Kyoto, JP;
Taiji Morimoto, Nara, JP;
Shinji Kaneiwa, Nara, JP;
Masahiro Yamaguchi, Tokai, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A semiconductor laser device comprises a substrate and a multi-layered crystal structure with an active layer for laser-oscillating operation, the multi-layered crystal structure being disposed on the substrate and having a striped channel area through which current is supplied to the active layer and a light-absorbing area positioned outside of the channeled area by which a difference between the amount of light to be absorbed inside of the channeled area and the amount of light to be absorbed outside of the channeled area is created, which causes a difference in the effective refractive index of the active layer, resulting in an optical waveguide in the active layer, wherein the active layer is flat and uniform and the width of the portion of the channel area in the vicinity of at least one facet is wider than that of the remaining portion of the channel area.