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:
Sep. 01, 1998
Filed:
Mar. 25, 1996
Tetsuro Okuda, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
The present invention provides a grating structure partially provided in a semiconductor laser device having a first facet of a first reflectivity and a second facet of a second reflectivity which is larger than the first reflectivity. The grating structure extends within a half area near the first facet in the semiconductor laser device. The grating structure has a grating length in a cavity direction of not more than one third of a cavity length defined as a distance between the first and second facets. The grating structure has an integrated coupling coefficient value in the range of 0.4-0.6, the integrated coupling coefficient value is obtained by integrating coupling coefficient of the grating structure with positions in the cavity direction.