Research of DOP and SOP for Feed-Forward PMD Compensation

摘要

PMD vectors can be described by Stokes vectors pointing to the direction of slow PSP with a length equal to DGD. Measuring DOP is a way of obtaining DGD information and the direction of PSP can be characterized by scrambling at the transmitter. When totally polarized optical signals (DOP=1) transmit a distance, DOP decreases due to the influence of PMD. However, if the input SOP is aligned to the direction of the PSP, DOP of optical signals remains unchanged. Placing a scrambler at the transmitter, SOP of input signals covers Poincare sphere at a certain frequency. The effect of PMD on SOPs in different directions changes with transmission, and the output DOP is described and shown. SOPs of two extreme points in the main axis are just two PSPs After one time scrambling, 3500 SOPs are distributed equally in the Poincare sphere The DOP of all SOPs can be calculated under the condition that splitting ratio is 0.5, with two SOPs at maximum DOP being two PSPs and two SOPs at minimum DOP being the SOP. Since the whole information of first-order PMD vector can be acquired, feed-forward PMD compensation will be feasible and fast.