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:
Oct. 19, 2004
Filed:
Aug. 21, 2002
Hideyuki Nasu, Tokyo, JP;
Takehiko Nomura, Tokyo, JP;
Tatsuhiko Ueki, Tokyo, JP;
Mamoru Shimada, Tokyo, JP;
Yuji Hiratani, Tokyo, JP;
The Furukawa Electric Co., Ltd., Tokyo, JP;
Abstract
An optical filter is provided on a first thermo-module whose temperature is controlled to be constant, via a base. Accordingly, a wavelength discrimination characteristic of the optical filter and an optical isolator can be stabilized, thereby realizing more accurate wavelength locking. Further, a second thermo-module is provided on the first thermo-module whose temperature is controlled to be constant. Accordingly, the temperature control range of the second thermo-module can be expanded, and hence the wavelength variable range of a semiconductor laser device provided on the second thermo-module via a base and a submount can be expanded.