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:
Feb. 01, 2005
Filed:
Mar. 14, 2001
Hirohiko Kobayashi, Kawasaki, JP;
Tsutomu Ishikawa, Kawasaki, JP;
Hajime Shoji, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A method of manufacturing a distributed feedback semiconductor laser, has the steps of: growing on a semiconductor substrate a lamination of alternately stacked lower barrier layer and lower well layer having a band gap narrower than the lower barrier layer, to form a lower quantum well structure; growing an intermediate layer on an uppermost lower well layer, the intermediate layer having a band gap broader than the lower well and a thickness thicker than the lower barrier layer; growing on the intermediate layer a lamination of alternately stacked upper well layer and upper barrier layer having a band gap broader than the upper well layer and a thickness thinner than the intermediate layer, to form an upper quantum well structure; forming a mask on the upper quantum well structure, the mask having periodical pattern; by using the mask as an etching mask, etching the upper quantum well structure in a periodical shape by using the intermediate layer as an etching margin layer; and removing the mask. Complex coupling DFB lasers with a small variation in characteristics can be provided.