基于多边带调制产生全光正交频分复用信号的研究

Study on Generation of All-Optical Orthogonal Frequency Division Multiplexing Signals Based Multi-Tones Modulation

研究了基于双臂马赫-曾德尔调制器(MZM)产生全光正交频分复用信号的原理,讨论了正交光子载波的产生由MZM的射频驱动和直流偏置电压决定的特性;并对基于载波抖动对系统的损伤定义了一个新的参数——载波均衡,以准确地描述产生全光正交频分复用载波的传输性能。根据选择的载波均衡参数,得到了产生2,3,4和5条正交光载波的最佳工作点;在接收端采用改进的马赫-曾德尔延时干涉仪和光门实现全光离散傅里叶变换,并测得了光门的相位取值和接收端滤波器带宽对接收信号误码性能的影响;最后研究了基于5条正交光边带100 Gb/s全光正交频分复用的传输系统性能。

The characterics of the all-optical orthogonal frequency division multiplexing（OFDM） generation based on a dual-arm Mach-Zehnder molulator（MZM） is investigated.It was found that the all optical OFDM subcarriers generation greatly depend on radio frequency（RF） and DC bias voltage of the dual-arm MZM.The system degradation induced by carrier fluctuation on the OFDM transmission performance was studied.A new parameter,namely carrier equalization was defined,and it can accurately describe the quality of the all-optical OFDM carrier generation.Different best working points have been selected to generate 2,3,4 and 5 orthogonal optical sidebands by adjust the parameters.At the receiver end,OFDM demodulation based on optical discrete Fourier transform was realized by using the Mach-Zehnder time delay interferometer and the optical gate.The bit error performance versus the phase of optical gate and bandwidth of optical filter was measured and at last,the performance of a 5×20 Gb/s transmission system based on all optical OFDM was studied.