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:
Nov. 07, 2006
Filed:
Jul. 30, 2004
Yuji Tamura, Yokohama, JP;
Yuji Tamura, Yokohama, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
In an optical amplifier of the present invention, a part of an input light output from a transmission path fiber is branched as a monitor light, a frequency component corresponding to a period at which a header area of a framed signal light appears, is extracted, and when a voltage level of a direct-current signal obtained by direct-current converting the frequency component becomes lower than a reference voltage, the input interruption of the signal light is detected, to perform a shut-down control of a pumping light source. Thus, an optical amplifier of low cost capable of suppressing an influence of a noise light while ensuring the immediacy, is provided.