WDM 系统中先进光纤传输调制格式的调研

Modulation technology is one of the key technique of DWDM system, this paper explained the principle of produce and comparison of some optical modulation technology(including NRZ,RZ,CS-RZ,RZ-DPSK,CSRZ-DPSK).Then we particularly introduced the newest modulation technology and experimentation:6*42.7-Gb/s transmission over ten 200-km EDFA-amplified SSMF spans using polarization-alternating RZ-DPSK; Electronic Signal Processing for Differential Phase Modulation Formats; Low phase noise photonic millimeter-wave generation by using a reciprocating optical modulator; Chromatic dispersion and SPM tolerance of 8-state/symbol (binary ASK and QPSK) modulated signal. Finally this paper provided the model set-up and simulation based on LiNbO3 modulator. The simulation result shows that NRZ is largely used in middle and short distance optical-fiber transmission system for its tighten frequency spectrum structure and easily practiced; CSRZ-DPSK is one of the best choice of long distance and high speed optical-fiber transmission system, because it has better frequency spectrum structure and Chromatic dispersion non-linear tolerance and its cost is lower than others.