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:
Nov. 27, 2012
Filed:
Sep. 13, 2010
Tsuyoshi Yamamoto, Kawasaki, JP;
Manabu Matsuda, Kawasaki, JP;
Tsuyoshi Yamamoto, Kawasaki, JP;
Manabu Matsuda, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
An optical semiconductor device is disclosed including an active region including an active layer and a diffraction grating having a λ/4 phase shift; passive waveguide regions each including a passive waveguide and a diffraction grating, disposed on the side of an emission facet and on the side of a rear facet sandwiching the active region between the passive waveguide regions, respectively; and an anti-reflection coating applied on the emission facet, wherein the passive waveguide region on the side of the emission facet has a length shorter than a length of the passive waveguide region on the side of the rear facet side.