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. 11, 2003
Filed:
Jun. 21, 2001
Takayuki Miyakawa, Kamifukuoka, JP;
Noboru Edagawa, Kamifukuoka, JP;
Masatoshi Suzuki, Kamifukuoka, JP;
KDD Submarine Cable Systems, Inc., Tokyo, JP;
Abstract
The object of this invention is to improve SNR in the Raman amplification. An optical fiber ( ) consists of a dispersion shift fiber in which a zero dispersion wavelength is shifted to the 1.55 &mgr;m band, and an optical fiber ( ) consists of a single mode optical fiber having the effective core area of 100 &mgr;m which is larger than that of the optical fiber ( ). An optical coupler is disposed at the optical signal emission end of the optical fiber ( ). A laser diode ( ) outputs the laser light of 1455 nm as a Raman pumping light source. The output light from the laser diode ( ) is introduced into the optical fiber ( ) from the back, namely in the opposite direction to that of the optical signal propagation. The ratio of the Raman gain coefficient of the optical fiber ( ) to that of the optical fiber ( ) should be 1/1.08 or less, preferably 1/1.1 or less.