Outage Statistics in a Waveplate Hinge Model of Polarization-Mode Dispersion

The properties of the waveplate hinge model of polarization-mode dispersion (PMD) are studied in detail, and its statistics are compared to those of the traditional hinge model based on the assumption of an isotropic output after each hinge. In particular, the probability density function of the differential group delay for each individual frequency band is computed using a combination of importance sampling and the cross-entropy method. The outage probability is then obtained combining these results with the outage map method, allowing the fraction of bands with unacceptable outage probabilities to be quantified by the noncompliant capacity ratio (NCR). The results show that the traditional hinge model significantly overestimates the NCR compared to the waveplate hinge model.

I. Introduction

Polarization-Mode Dispersion (PMD) is one of the obstacles facing the next generation of optical fiber communication systems [1]. Since the birefringence of installed optical fiber varies randomly with respect to both time and wavelength, the effect of PMD on a system is stochastic in nature. This problem is dealt with by allotting a power penalty to PMD. The outage probability (i.e., the probability of the PMD-induced penalty exceeding this allowed value), then becomes a key measure of the reliability of a system.