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:
Apr. 12, 1994
Filed:
Jun. 29, 1993
Hiroaki Kudo, Nara, JP;
Haruhisa Takiguchi, Nara, JP;
Kazuhiko Inoguchi, Nara, JP;
Chitose Nakanishi, Nara, JP;
Satoshi Sugahara, Nara, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A distributed feedback semiconductor laser device comprising a current blocking structure having a stripe groove, and a diffraction grating formed in the bottom of the stripe groove. The current blocking structure is formed over an active layer for laser oscillation, and it includes an etch stop layer against a groove etching in a lower potion of the current blocking structure. The refractive index distribution in transverse directions inside the stripe groove is controlled by the thickness of the optical guiding layer, enabling oscillation of the fundamental transverse mode.