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. 03, 1992
Filed:
Apr. 18, 1990
Akira Takemoto, Itami, JP;
Hitoshi Watanabe, Itami, JP;
Masatoshi Fujiwara, Itami, JP;
Syoichi Kakimoto, Itami, JP;
Abstract
A semiconductor laser device having an active layer sandwiched by semiconductor layers having larger energy band gaps than that of the active layer, includes a semiconductor absorption layer having an energy band gap no larger than that of the active layer and having a thickness periodically changing in the cavity length direction of the resonator close to the active layer so that light which is generated at the active layer reaches the absorption layer, and a semiconductor refractive index matching layer having a larger energy band gap than that of the active layer and a higher refractive index than those of the semiconductor layers sandwiching the active layer to make the equivalent refractive indices in layer thickness direction substantially equal along the resonator direction.