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:
Oct. 04, 1988
Filed:
Jul. 26, 1985
Naoki Chinone, Hachioji, JP;
Shinji Tsuji, Hachioji, JP;
Yoshihisa Fujisaki, Setagaya, JP;
Yasutoshi Kashiwada, Nishitama, JP;
Motohisa Hirao, Suginami, JP;
Hitoshi Nakamura, Hachioji, JP;
Akio Oishi, Kokubunji, JP;
Kenji Hiruma, Koganei, JP;
Tadashi Fukuzawa, Setagaya, JP;
Hiroyoshi Matumura, Iruma, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A distributed feedback semiconductor laser provided with a grating which effects optical feedback by means of periodic corrugation disposed inside an optical resonator. The optical resonator has at least two regions having different Bragg wavelengths, and these regions are arranged longitudinally in the direction of an optical axis. The laser device can realize stable single longitudinal mode oscillation through variation of the refractive indexes of the regions nonuniformly around an average value.