Being the method of appraising the effective Raman profit quality of the optical fiber which possesses the evaluation method of Raman profit quality of the optical fiber

摘要

PROBLEM TO BE SOLVED: To provide an evaluation method for the Raman gain characteristics of an optical fiber, an estimation method for its Raman gain characteristic spectrum, and an evaluation device for the Raman gain characteristics, which are simple and very precise.;SOLUTION: The Raman gain characteristics evaluation method is conducted to measure the refractive index n(r,λ) for a light of a wavelength λ at a position r from the center axis of the cross section of an optical fiber which is an object to be measured having an arbitrary refractive index distribution, and an electric field distribution E(r,λ_s) at a position r from the center axis of the cross section of the optical fiber which is an object to be measured at a signal light wavelength λ_s. In this method, the Raman gain coefficient g_R(r,λ_s), at a position r from the center axis of the cross section of the optical fiber at the wavelength λ_s frequency-shifted from an excitation light wavelength λ_p, is found by means of Formula (1); as well as an effective Raman gain rate C_Reff(λ_s) of the optical fiber at the wavelength λ_s is found by Formula (2), and by means of Formula (3) an effective Raman gain coefficient g_Reff(λ_s) at the wavelength λ_s is calculated.;COPYRIGHT: (C)2005,JPO&NCIPI