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:
Jun. 25, 2019
Filed:
Sep. 29, 2016
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Tohoku University, Miyagi, JP;
Hiroyuki Ishii, Atsugi, JP;
Naoki Fujiwara, Atsugi, JP;
Kei Watanabe, Atsugi, JP;
Mikitaka Itoh, Atsugi, JP;
Keisuke Kasai, Sendai, JP;
Masataka Nakazawa, Sendai, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Tohoku University, Miyagi, JP;
Abstract
A configuration of a DFB laser-based wavelength tunable laser is well known, but long resonators have difficulty in forming uniform resonators due to production variations, thereby inducing limitation in narrowing the spectral linewidth in the DFB laser-based wavelength tunable laser as well. In the semiconductor laser device of the present invention, a semiconductor laser that oscillates in a single mode and a low-loss lightwave circuit using SiOglass are arranged on the common substrate. The lightwave circuit is configured such that part of output light from the semiconductor laser propagates through a certain length of an optical path, and then is reflected by a reflector and is fed back to the semiconductor laser. Output light from the semiconductor laser and an input waveguide of the lightwave circuit can also be configured to be optically connected directly to each other. The present invention can provide a compact laser device with a narrowed spectral linewidth and stable wavelength controllability.