Research On The Nonlinear Effects Of DPSK Optical Fiber Communication Systems

With the continued increase of the requirements of the large capacity, long-distance communication system, the 40Gb/s optical fiber communication system has gradually begun to commercial from the laboratory. With the increase of capacity and distance, the nonlinear effects of the transmission performance of optical fiber communication systems have become increasingly prominent, while the use of DPSK modulation is considered to be an important technical resistance to nonlinear effects. This thesis studies the nonlinear effects of a DPSK optical fiber communication systems.To study the nonlinear effects of DPSK optical fiber communication systems, in the thesis, the method is to compensate the linear effects of system to reduce the impact of the linear effects of the system. OptiSystem is applied to simulate and design the system. The design of single channel DPSK optical fiber communication systems is applied to observe the impact of self phase modulation (SPM) on system performance; The design of multi-channel DWDM system is applied to observe the impact of cross phase modulation (XPM), four wave mixing (FWM) on system performance.First, in the thesis, the theoretical basis of DPSK optical fiber communication system is discussed; Second, the model of DPSK optical fiber communication system is established, the simulation of 40Gb/s system is applied on OptiSystem software platform. The design of single channel DPSK optical fiber communication system, respectively, the input of RZ-DPSK signal and CSRZ-DPSK signal differently into the fiber power of simulation results to determine the appropriate fiber input power and threshold power; Third, in different distance of single channel system, the compare of Q factor, bit error rate and eye diagram conclude that RZ-DPSK and CSRZ-DPSK have the similar resistance of SPM; Finally, the design is based on DWDM DPSK optical fiber communication system model, in different distance, in the 8 channels and 16 channels, the compare of Q factor, bit error rate and eye diagram come to the conclusion that CSRZ-DPSK have a better resistance of XPM and FWM than RZ-DPSK, and CSRZ-DPSK is more suitable for DWDM systems.