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:
May. 02, 1989
Filed:
Aug. 11, 1986
Tadashi Fukuzawa, Tokyo, JP;
Naoki Chinone, Hachioji, JP;
Shin'ichi Nakatsuka, Kokubunji, JP;
Katsutoshi Saito, Higashiyamato, JP;
Takashi Kajimura, Tokyo, JP;
Yuuichi Ono, Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A semiconductor laser device including at least one of a laser active layer formed of a super lattice and an optical guide layer formed of another super lattice is disclosed in which part of at least one of the super lattices is converted into a mixed crystal by the impurity induced disordering based upon one of impurity diffusion and impurity ion implantation, to divide the super lattice into a first region formed of the mixed crystal and a second region having the super lattice structure, the width of the second region in directions perpendicular to the lengthwise direction of a laser cavity varies along the above lengthwise direction, and the width of a laser excitation region is smaller than the mean value of the width of the second region, to generate laser oscillation having a single transverse mode and a multi longitudinal mode. Thus, the semiconductor laser device emits a laser beam which is small in astigmatism and low in optical feedback noise.