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. 02, 2021
Filed:
Nov. 01, 2019
Furukawa Electric Co., Ltd., Tokyo, JP;
Junji Yoshida, Tokyo, JP;
Hirokazu Itoh, Tokyo, JP;
Satoshi Irino, Tokyo, JP;
Yuichiro Irie, Tokyo, JP;
Taketsugu Sawamura, Tokyo, JP;
Masaki Funabashi, Tokyo, JP;
Nobumasa Tanaka, Tokyo, JP;
FURUKAWA ELECTRIC CO., LTD., Tokyo, JP;
Abstract
A distributed feedback (DFB) laser outputting a predetermined wavelength of laser light includes a quantum well active layer positioned between a p-type cladding layer and an n-type cladding layer in thickness direction. The DFB laser includes a separate confinement heterostructure layer positioned between the quantum well active layer and then-type cladding layer. The DFB laser includes an electric-field-distribution-control layer positioned between the separate confinement heterostructure layer and then-type cladding layer and configured by at least two semiconductor layers having band gap energy greater than band gap energy of a barrier layer constituting the quantum well active layer. The DFB laser has a function to select a specific wavelength by returning a specific wavelength in the wavelength-variable laser.