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:
Aug. 18, 2009
Filed:
Nov. 13, 2007
Kazushige Kawasaki, Tokyo, JP;
Yasuyuki Nakagawa, Tokyo, JP;
Hiromasu Matsuoka, Hyogo, JP;
Mitsubishi Electric Corporation, Tokyo, JP;
Abstract
A semiconductor laser device comprises a GaN substrate having a refractive index of 3.5 or below, a semiconductor layer laminated on the substrate, and a pair of facets forming a resonator and in face-to-face-relation to each other in a direction perpendicular to the direction of the laminated layer. One of the facets of the resonator includes a low reflection film, of a first dielectric film, a second dielectric film, a third dielectric film, and a fourth dielectric film. When the refractive indexes of these films are taken as n, n, n, and n, nand n=n. The following relationship between the first dielectric film and the third dielectric film, and between the second dielectric film and the fourth dielectric film is established, nd+n'd′=pλ/4, where p is an integer, and λ is oscillation wavelength of a laser beam generated by the semiconductor laser device.