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:
Jul. 19, 2011
Filed:
Sep. 04, 2009
Akinori Hayakawa, Kawasaki, JP;
Akinori Hayakawa, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
An optical semiconductor device includes a semiconductor laser, a first optical waveguide, an optical coupler for branching light guided from the semiconductor laser through the first optical waveguide into two lights, two second optical waveguides, diffraction gratings provided individually on the two second optical waveguides, and an optical detector for detecting light guided through one of the two diffraction gratings, and the components are provided on the same substrate. The optical semiconductor device is configured such that reflection returning lights from the diffraction gratings side to the semiconductor laser side interfere with each other and thereby extinguish each other at the optical coupler and the phases of the reflection returning lights from the diffraction gratings side are displaced from each other by π at the optical coupler portion.