Chapter 5 - Polarization Effects in Optical Fiber

Abstract

This chapter performs a study on polarization effects from the standpoint of optical orthogonal frequency-division multiplexing (OFDM) systems. Single-mode fiber (SMF) supports two polarization modes. The asymmetry of optical fiber leads to polarization mode coupling or random polarization rotation along a sufficiently long fiber, which is called polarization mode dispersion (PMD). This polarization effect has long been considered a nuisance rather than a benefit to take advantage of in the mainstream of optical communications. Random polarization rotation can be overcome by using a polarization maintain fiber (PMF). The polarization dispersion effect has been studied since the very early stages of optical fiber communications. However, it has only been considered synonymous with PMD since Poole and Wagner's seminal work.1 In the context of optical OFDM, it seems that the channel transfer function of Jones matrix is more convenient for describing the dispersion effect. In this section, one discusses the fundamentals of the polarization dispersion effect, including its origin, the Jones matrix representation, the concept of PMD, the stochastic properties of PMD, the autocorrelation function of the Jones matrix, and polarization dispersion impairment in conventional transmission systems.