中文摘要：

针对传统马赫-曾德尔调制器（MZM）在光载正交频分复用（OFDM）系统中的非线性失真问题,提出了一种新的并行MZM结构,该结构由主调制器和起补偿作用的子调制器组成。理论分析与仿真表明：通过设计调制器电极长度与输入光功率,使得相位误差衰减因子小于1,此时并行MZM的非线性失真小于传统MZM。在相同调制指数下,并行MZM对应的星座图更加收敛,但随着调制指数的增加而逐渐发散。

英文摘要：

A new dual-parallel Mach-Zehnder modulator（MZM） consisting of a primary modulator and a compensative sub-modulator was applied to reduce the signal nonlinear distortion in Coherent Optical OFDM（CO-OFDM） systems.Analysis and simulation results show that the signal nonlinear distortion of dual-parallel MZM is less than that of conventional MZM when phase error attenuation factor is less than 1 by designing modulator electrode length and input optical power.With the same modulation index,the constellation diagram of dual-parallel MZM is much more convergent than that of conventional MZM.While with the increase of modulation index,the constellation diagram gradually becomes divergent.