Optical Performance Monitoring On Mode Division Multiplexing Signal By Asynchronous Amplitude Sampling

Over the years,in order to break through the limit of transmission capacity of single mode fiber,few-mode fiber improve the communication capacity greatly,but the increase of capacity,rate made a dramatic increase in transport damage.CD,PMD,and OSNR are significant.urgently needs a kind of online monitoring scheme to carry on the effective monitoring to the mode division multiplexing signal,so as to provide theory support for the optimization of channel.In this thesis,performance monitoring of multiplexing signal can be expanded into the following several aspects.Firstly this thesis studied the existing OPM technical scheme,analyzed the characteristics of directly monitoring system and the digital coherent system monitoring,studied a new type of asynchronous sampling?AAH?monitoring scheme to monitor for QAM signal in digital coherent system,and the theory deduced the mathematical relationship among one to three order origin moment of asynchronous amplitude sampling,noise and the dispersion,put forward the dimensionless factor dispersion parameters C_d,the parameter factor has high sensitivity to dispersion.Other damage factors such as noise has less effect on C_d.It reduces the influence of OSNR and other damages on monitoring results and greatly improves the monitoring effect.The second,the 6-by-6 mode multiplexing system based on photonic lanterns designed in this thesis can realize the 6-by-6 mode exchange,the monitoring of any node and the mode balance.The last,this thesis used Optisystem built 400 Gb/s 1024-QAM transmission platform.In the case of different gaussian filter bandwidth,signal-to-noise ratio and duty ratio,we completed the simulation experiment of dispersion monitoring.we can draw that within 0²00 ps/nm the system has high sensitivity,in 0⁶00 ps/nm range that can realize the basic monitoring results.This monitoring system has high precision,large monitoring range and little influence from noise.Without demodulating the received signals,the OPM technique proposed in this paper based on AAH can detect the quality of signals.The received signal is sampled asynchronously,resulting in low cost and highly reliable,therefore,the OPM techniques can be applied to monitoring the residual chromatic dispersion of a transmission link in the next-generation optical networks.