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:
Jun. 26, 2001
Filed:
Mar. 05, 1999
Katsunobu Sasanuma, Tokyo, JP;
Shinji Saito, Yokohama, JP;
Genichi Hatakoshi, Yokohama, JP;
Kazuhiko Itaya, Yokohama, JP;
Masaaki Onomura, Kawasaki, JP;
Risa Sugiura, Kawasaki, JP;
Mikio Nakasuji, Kawasaki, JP;
Hidetoshi Fujimoto, Kawasaki, JP;
Masahiro Yamamoto, Kawasaki, JP;
Shinya Nunoue, Ichikawa, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A semiconductor laser is formed of gallium nitride series compound semiconductor and has a double hetero structure including an MQW (multiple quantum well) active layer held between p-type and n-type AlGaN clad layers. The double hetero structure is held between p-type and n-type contact layers. An InGaN optical absorption layer having an optical absorption coefficient larger than the clad layer which has the same conductivity type as the contact layer and is formed adjacent to the contact layer is formed in at least one of the contact layers and an InAlGaN optical guided mode control layer (layer of small refractive index) having an refractive index smaller than the clad layer is formed on the exterior of the optical absorption layer.