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. 27, 2004
Filed:
Nov. 15, 2001
Applicant:
Inventors:
Masaki Funabashi, Tokyo, JP;
Satoshi Arakawa, Tokyo, JP;
Assignee:
The Furukawa Electric Co., Ltd., Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
H01S 5/12 ;
U.S. Cl.
CPC ...
H01S 5/12 ;
Abstract
A distributed feedback (DFB) semiconductor laser device has a multiple-quantum-well (MQW) structure and a diffraction grating formed in the MQW structure. The diffraction grating includes a grating structure formed in QW layers and a barrier layer of the MQW structure and an embedded layer embedded in the grating structure. One of the QW layers and the barrier layers has an etching rate lower than the etching rate of the other layers of the MQW structure and functions as an etching stop layer during etching of the MQW structure for forming the diffraction grating.