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:
Mar. 09, 1993
Filed:
Jan. 21, 1992
Takashi Murakami, Itami, JP;
Nobuaki Kaneno, Itami, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A visible light semiconductor laser device has a double heterojunction structure comprising AlGaInP series semiconductors which is produced on a substrate having an electrode on its rear surface. A a p type GaInP buffer layer is provided between a p type GaAs contact layer and a p type AlGaInP cladding layer. The buffer layer has a constant composition ratio and the energy band gap is smaller at the side of the p type GaAs contact layer than at the p type AlGaInP cladding layer. Thus, an energy band discontinuity between the p type GaAs contact layer and the p type AlGaInP cladding layer are relaxed for operation of the laser at low voltage. The laser is produced by varying the growth conditions, such as temperature or V/III ratio during growth, of the buffer layer to vary the energy band gap within the buffer layer.