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. 23, 2004
Filed:
Apr. 11, 2002
Sony Corporation, Tokyo, JP;
Abstract
Disclosed is a nitride based III-V group compound semiconductor laser device of ridge waveguide type with an oscillation wavelength of about 410 nm which has a low driving voltage, a high half-width value &thgr; of a FFP in a direction horizontal to a hetero interface, and a high kink level (i.e., good light output-injected current characteristics over the high-output range). This laser device is similar in structure to the related-art semiconductor laser device except for the current constricting layer formed in a ridge. It has a stacked film composed of an SiO film (600 Å thick) and an amorphous Si film (300 Å thick) which are formed on the SiO film by vapor deposition. The stacked film covers both sides of the ridge and a p-AlGaN cladding layer extending sideward from the base of the ridge. The SiO film and Si film have respective thicknesses which are established such that the absorption coefficient of fundamental horizontal lateral mode is larger than the absorption coefficient of primary horizontal lateral mode. This structure results in a higher kink level, while suppressing the high-order horizontal lateral mode, a larger effective refractive index difference &Dgr;n, and a larger value of &thgr; without the necessity for reducing the ridge width.