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. 24, 2004
Filed:
Jun. 05, 2001
Saeid Seydnejad, Ottawa, CA;
Zhuhong P. Zhang, Ottawa, CA;
Nortel Networks Limited, St. Laurent, CA;
Abstract
In a method and apparatus for measuring and controlling signal gain of a backward Raman amplifier having multiple pump lasers as used in optical communications networks, Raman pump power levels required to provide a uniform gain across a range of wavelengths in an optical fiber are determined by a combination of theoretical calculations and empirical measurement. A system of non-linear differential equations is solved for various pump powers and used to build a look-up table relating desired average Raman gain to the normalized power required to provide a uniform gain across a range of wavelengths. The linear relationship between Raman pump power and average Raman gain is determined by measuring data signal power levels at specific Raman pump powers. A desired average Raman gain is first applied to the linear relationship to determine total power required, and then applied to the look-up table to determine the required relative pump powers.