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:
Sep. 29, 2009
Filed:
Jun. 02, 2004
Koji Otsubo, Kawasaki, JP;
Yoshiaki Nakata, Kawasaki, JP;
Koji Otsubo, Kawasaki, JP;
Yoshiaki Nakata, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
The optical semiconductor device comprises an active layer including a plurality of quantum dot stackseach of which is formed of a plurality of quantum dot layersand a plurality of first layersalternately stacked, and a plurality of second barrier layersthicker than the first barrier layersstacked alternately with the quantum dot stacks. Thus, the quantum dot layers can be stacked with the generation of dislocations due to lattice mismatching between the substrate and the quantum dots suppressed. A number of quantum dot layers can be stacked with a desired light confinement coefficient ensured. The optical semiconductor device can have the characteristics easily improved.