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:
Jul. 29, 2008
Filed:
Mar. 18, 2005
Goji Nakagawa, Kawasaki, JP;
Hideyuki Miyata, Kawasaki, JP;
Yutaka Kai, Kawasaki, JP;
Hiroshi Onaka, Kawasaki, JP;
Setsuo Yoshida, Yokohama, JP;
Kyosuke Sone, Kawasaki, JP;
Tomohiro Ueno, Yokohama, JP;
Goji Nakagawa, Kawasaki, JP;
Hideyuki Miyata, Kawasaki, JP;
Yutaka Kai, Kawasaki, JP;
Hiroshi Onaka, Kawasaki, JP;
Setsuo Yoshida, Yokohama, JP;
Kyosuke Sone, Kawasaki, JP;
Tomohiro Ueno, Yokohama, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
An optical transmission device improved in quality and reliability of OADM function and permitting configuration of highly-flexible, economical OADM networks. A wavelength tunable filter variably selects a wavelength according to a control frequency. A filter controller applies the control frequency to the filter while scanning wavelength over an entire signal bandwidth, to detect, from a reference wavelength monitor signal supplied thereto, a reference control frequency which permits the filter to select a reference wavelength and according to which wavelength is matched. On receiving a wavelength selection request, the controller obtains a target control frequency from the reference control frequency and the position of a target wavelength relative to the reference wavelength, and applies the obtained frequency to the filter. A reference wavelength filter transmits the reference wavelength therethrough. A light-receiving element monitors the transmitted reference wavelength to generate the monitor signal.