Beat length characterization based on backscattering analysis in randomly perturbed single-mode fibers

This paper presents analytical and numerical results on the statistical pro perties of the backscattering signal of a randomly perturbed, linearly bire fringent, single-mode fiber. Our theory is based on the study of amplitude evolution of the backscattered field passed through a linear polarizer, ali gned with the state of polarization of the input signal. In particular, we show that the mean value of the beat length can be calculated using two met hods based, respectively, on a level crossing rate analysis of the backscat tered signal and on the evaluation of the standard deviation of its spectra l density.