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:
Aug. 14, 1990
Filed:
Dec. 05, 1988
Yasuo Ohba, Yokohama, JP;
Niyoko Watanabe, Halifax, CA;
Hideto Sugawara, Tokyo, JP;
Masayuki Ishikawa, Tokyo, JP;
Yukio Watanabe, Yokohama, JP;
Motoyuki Yamamoto, Kawasaki, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A double-heterostructure semiconductor laser is disclosed which has a semiconductive substrate of a first conductivity type made of III-V compound semiconductor material, a first semiconductive cladding layer of the first conductivity type disposed above the substrate, an active layer made of a semiconductor film provided on said cladding layer to serve as a light emission layer, and a second semiconductive cladding layer of a second conductivity type provided on the active layer to define a light waveguide channel of the laser. The second cladding layer is made of a compound semiconductor containing indium, phosphorus, and aluminum. A contact layer section is provided on the second cladding layer to cover the light waveguide channel. The contact layer is made of a compound semiconductor material containing gallium and arsenic, and has a band gap discontinuity at a boundary region of the light waveguide channel to form a barrier which serves to effectively seal current carriers in the waveguide channel, while the laser is emitting a laser light. This contact layer may also serve as a current-blocking layer.