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. 06, 2004
Filed:
Aug. 17, 2001
Toshihiro Ohtani, Sapporo, JP;
Futoshi Izumi, Kawasaki, JP;
Shota Mori, Kawasaki, JP;
Tsukasa Takahashi, Sapporo, JP;
Hideki Kobayashi, Sapporo, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A Raman excitation control method enabling to reduce the number of couplers and photodetectors (PD) for providing an optical transmission unit with reduced cost. The method is provided for use in optical amplification to amplify an optical signal using Raman excitation light fed into an optical transmission line. A backward light of a laser diode producing the Raman excitation light is monitored by an optical back power monitor. The monitored power value is compared with an initial set value stored in a memory for the laser diode. Based on this comparison result, a feedback control is performed against the light emission power of the laser diode.