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:
May. 25, 2010
Filed:
May. 14, 2009
Tetsuya Uda, Yokohama, JP;
Kenta Noda, Yokohama, JP;
Yasuhiro Uchiyama, Yokohama, JP;
Hiroshi Masuda, Yokohama, JP;
Hiroyuki Nakano, Yokohama, JP;
Tetsuya Uda, Yokohama, JP;
Kenta Noda, Yokohama, JP;
Yasuhiro Uchiyama, Yokohama, JP;
Hiroshi Masuda, Yokohama, JP;
Hiroyuki Nakano, Yokohama, JP;
Hitachi Communication Technologies, Inc., Tokyo, JP;
Abstract
An optical transmission apparatus comprising a first detector for detecting the power of the supervisory signal light separated from received wavelength-division multiplexed signal lights; a second detector for detecting the power of the wavelength-division multiplexed signal lights after the separation of the supervisory signal light; a gain-controlled type optical amplifier for amplifying the wavelength-division multiplexed signal lights; an optical attenuator coupled to the amplifier; and a control unit for controlling the optical amplifier and the optical attenuator so as to keep the output level of the wavelength-division multiplexed signal lights to a predetermined target value, wherein the control unit restrains automatic output level control by the optical attenuator when the supervisory signal light power fluctuates within its permissible range and fluctuations in the signal light power have deviated from its permissible range.