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. 03, 2017
Filed:
Jan. 27, 2015
Oki Electric Industry Co., Ltd., Tokyo, JP;
Hideaki Okayama, Tokyo, JP;
Oki Electric Industry Co., Ltd., Tokyo, JP;
Abstract
An optical wavelength demultiplexer includes a wavelength demultiplexing device, a first wavelength filter and a first- and second-stage wavelength sub-filters. The wavelength demultiplexing device demultiplexes an input light into a first wavelength band including wavelengths λand λin the vicinity of 1310 nm and a second wavelength band including a wavelength λof 1490 nm and a wavelength λof 1550 nm to output. The first-stage wavelength sub-filter removes the wavelength λlonger than 1310 nm from the second wavelength band and transmits the wavelength λof 1490 nm. The second-stage wavelength sub-filter removes the wavelength λof 1550 nm and outputs the wavelength λof 1490 nm, which is the remainder of the selected lights, with a sufficient wavelength spectral purity.