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:
Feb. 01, 2011
Filed:
Jun. 23, 2009
Kosuke Komaki, Kawasaki, JP;
Yuji Tamura, Kawasaki, JP;
Kosuke Komaki, Kawasaki, JP;
Yuji Tamura, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
An optical amplifier includes a first optical amplification unit that amplifies input light, a variable optical attenuation unit that attenuates an output of the first optical amplification unit, a second optical amplification unit that amplifies an output of the variable optical attenuation unit, and a loss amount control unit that controls the variable optical attenuation unit, wherein an external attenuating optical medium is inserted between the variable optical attenuation unit and the second optical amplification unit. The optical amplifier includes an abnormality detecting unit that detects abnormality in optical loss based on a light level between the external attenuating optical medium and the second optical amplification unit, and a detection invalidating unit that invalidates any abnormality detected by the abnormality detecting unit when a light level between the variable optical attenuation unit and the external attenuating optical medium is lower than a threshold level.