With the continuous improvement of the optical fiber communication rate, polarization mode dispersion (PMD: Polarization mode dispersion) is gradually depth. PMD will cause the light pulse signal wide during transmission, and in the signal transmission process continuous accumulation, damage to the transmission performance of the system, limit the system's transmission rate and transmission distance, PMD began to be the main obstacle which constrained optical fiber communication system upgrade and further development. PMD is a random value and difficult to calculate and test in the actual optical fiber communication systems. Poincare method is intuitive, easy to understand, easy measurement to study the characteristics of the PMD, and avoid a lot of tedious calculations. In the paper, analysis the single-mode fiber and its PMD, and the polarization state transmission process of polarization maintaining fiber and its nonlinear effects using the Poincare method, and simulate PMD characteristics by using Matlab software. Based on these, introduce the measurement principle of an improved Poincare method. Analysis showed that the Poincare sphere is a unique method in the analysis of fiber-optic polarization state transmission. Poincare method for the study of polarization mode dispersion has become an important direction of today's communications field.
Receiver Model for Depolarized Signal Due to Polarization-Mode Dispersion and Partially Polarized Noise Due to Polarization-Dependent Loss in an Optical Fiber Communication System