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:
Jul. 13, 1993
Filed:
Feb. 04, 1992
Akira Takemoto, Itami, JP;
Etsuji Omura, Itami, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A semiconductor laser device includes a p type semiconductor substrate, an active layer having a smaller energy band gap than the p type semiconductor substrate and an n type semiconductor layer having a larger energy band gap than the active layer successively formed on the p type semiconductor substrate, a mesa formed by selectively etching the semiconductor substrate, active layer, and n type semiconductor layer, p-n-p layers having larger energy band gaps than the active layer and disposed at both sides of the mesa, a small energy band gap layer having a smaller energy band gap than the p type semiconductor substrate and disposed on the p-n-p layers, and an n type semiconductor layer disposed on the small energy band gap layer and on the n type semiconductor layer. The small energy band gap layers decrease the current flowing through the thyristor structure and are disposed close to the active region but in a different processing step from the formation of the active layer. A waveguide structure in which the active layer is surrounded by semiconductor layers having larger energy band gaps is realized.