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. 03, 1997
Filed:
Dec. 27, 1994
Kentaro Tada, Tokyo, JP;
Hiroyuki Yamazaki, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
It is the object of the invention to provide a semiconductor laser with a low threshold lasing current and a high external differential quantum efficiency. A n-type AlGaInP clad layer 2, a AlGaInP MQW active layer 3, a p-type AlGaInP clad layer 4, p-type GaInP hetero-buffer layer 5 and a-type GaAs layer 6 are successively grown on a n-type GaAs substrate 1, wherein Al contents of a barrier in the MQW layer 3 is so varied that holes are uniformly distributed in each quantum well. Next, a mesa is formed by an etching process, then a n-type GaAs block layer 7 is grown, and electrodes are formed on both p and n-side surfaces. Finally, the processed substrate is cleaved, and laser diodes are obtained therefrom. An Al content of the barrier layer in the MQW active layer 3 is slowly decreased from a p-side to a n-side, and thereby holes are uniformly distributed in each quantum well and few electrons overflow a quantum well. The selected drawing is FIG. 6.
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