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. 21, 2006
Filed:
Mar. 05, 2004
Eisuke Nakamura, Hokkaido, JP;
Makoto Murakami, Hokkaido, JP;
Kiyotoshi Noheji, Kanagawa, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
An optical transmission apparatus that improves optical transmission quality by performing an optical noise correction and optical level detection with great precision. A first optical amplifier performs optical amplification with an optical fiber transmission line as an amplification medium. A second optical amplifier inputs second excitation light into an amplification medium in which an active substance for optical amplification is doped to perform optical amplification. A first optical level detector monitors, before transmitting an optical signal, a level of optical noise scattered by the first optical amplifier by emitting first excitation light in an operating environment and detects an optical level at the time of transmitting the optical signal by subtracting the level of the optical noise from a signal amplified by the first optical amplifier. A second optical level detector monitors, before transmitting an optical signal, a level of optical noise emitted from the second optical amplifier by emitting the second excitation light in the operating environment and detects an optical level at the time of transmitting the optical signal by subtracting the level of the optical noise from a signal amplified by the second optical amplifier.