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:
Jan. 27, 2004
Filed:
Jul. 11, 2002
Tomoto Tanaka, Sapporo, JP;
Miki Onaka, Kawasaki, JP;
Etsuko Hayashi, Kawasaki, JP;
Yasushi Sugaya, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
An object of the invention is to provide an optical amplification apparatus using Raman amplification, which can reliably judge an input interruption of signal light and can shut down the supply of excitation light in accordance with a judged input interruption of the signal light. To this end, the optical amplification apparatus of the present invention comprises an input interruption detection means for detecting a noise light component due to the Raman amplification, and judging an input interruption of the signal light based on the detection result, and further comprises a shut down control means for shutting down supply of the excitation light when an input interruption of the signal light is judged by the input interruption detection means. The input interruption detection means computes the noise light power due to the Raman amplification in accordance with monitored excitation light power, and corrects a threshold value as a judgment reference for an input interruption using the calculation result, and judges an input interruption of the signal light when a monitored value of the input light power to a second optical amplifying means is less than the post-correction threshold value.