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. 18, 2001
Filed:
Mar. 18, 1999
Yoshiaki Watanabe, Tsurugashima, JP;
Kiyoshi Takei, Tsurugashima, JP;
Nong Chen, Tsurugashima, JP;
Kiyofumi Chikuma, Tsurugashima, JP;
Pioneer Electronic Corporation, Tokyo, JP;
Abstract
There is provided a method of manufacturing a ridge type LC-DFB semiconductor laser in which a laser substrate having a cladding layer made of a material for a ridge stripe formed on an active layer made of semiconductor. A stripe mask is formed on the cladding layer to form two lateral flat portions from the cladding layer, by a selective wet etching, so as to form a ridge stripe protruding therefrom and having a flat top portion at which the stripe mask capped. A grating mask is formed on the two lateral flat portions, side walls of the ridge stripe and the stripe mask. The grating mask has a periodic structure in the direction in which the ridge stripe extends. The two lateral flat portions and the side walls of the ridge stripe are dry-etched through the grating mask and then the two lateral flat portions and the side walls of the ridge stripe are wet-etched to form a grating of the material for the ridge stripe on the two lateral flat portions, the side walls of the ridge stripe and the active layer, so as to define a bracket grating portion adjacent to the ridge stripe.