Optical Fiber Nonlinear Compensation Based On Phase Conjugation

In recent years,optical fiber communication has developed rapidly,and optical fiber communication systems with high speed and large bandwidth have gradually become the goal pursued by people.However,interference factors such as dispersion and nonlinear effects in optical fiber communication systems make it difficult for people to achieve this goal.Therefore,it is very important to be able to effectively compensate for non-linear effects and dispersion in communication transmission.Theoretically,the optical phase conjugation technology can not only effectively compensate the damage caused by the nonlinear effect of the optical fiber in transmission,but also has a corresponding compensation effect for the even-order dispersion of the optical fiber.And there is no photoelectric conversion in the optical phase conjugation technology,which can reduce the energy loss in the transmission process,so it has become a research hotspot.This thesis uses Maxwell's equation to find the solution of the wave equation,derives the transmission equation of the optical pulse,and explores the influence of factors such as nonlinearity and dispersion on the optical signal.The nonlinear Schrodinger equation is used to describe the principle of optical phase conjugation(OPC)compensation for nonlinear effects in optical fibers,and the conversion efficiency of four-wave mixing(FWM)is analyzed based on the OPC structure.First,from the theoretical basis,the mathematical expression of four-wave mixing conversion efficiency is deduced,and the factors related to the low conversion efficiency of four-wave mixing are analyzed.Then,the corresponding structural model is built using the Optisystem optical software platform,and aimed at Different FWM structures are simulated.This thesis studies the non-linear effect compensation effect of a single-channel optical fiber communication system under the conditions of different transmission rates and with or without OPC modules.The simulation results show that when the transmission rate is high,the OPC module has a significant compensation effect on the nonlinear effect in the optical fiber,which improves the system performance.On this basis,the optical phase conjugation technology combined with a variety of dispersion compensation structures is studied to compensate for nonlinear effects in the transmission system.From the two aspects of the transmission distance and speed of the communication system,the nonlinear effect compensation effect of OPC technology under various dispersion compensation structures is studied.The simulation results show that the effect of compensating nonlinear effects in the fiber is better under the structure of symmetrical compensation + OPC.