Determination of back-scatter coefficient from third-order Rayleigh effect in a Raman amplifier

We propose a precise measurement technique for the Rayleigh back-scattering coefficient based on a single-ended optical time-domain reflectometry trace analysis. By comparing the relative strength of the Rayleigh components-Rayleigh scattering and triple Rayleigh scattering-we show that it is possible to avoid the uncertainties associated with previous measurement techniques, achieving less than 0.1-dB error in the determination of the Rayleigh coefficient. Application of this technique to the noise characterization of the fiber Raman amplifiers will be provided at the end.