探测器非线性对三阶交调失真的影响

Influence of photodiode nonlinearity on the third-order inter-modulation distortion

建立了基于双电极马赫-曾德尔调制器和非线性光电探测器的双音调制直接探测链路模型,推导了探测器非线性条件下系统基阶信号和三阶交调信号功率表达式,分析了探测器非线性对链路三阶交调失真的影响。结果表明,探测器非线性在特定参数条件下会更好地抑制三阶交调失真,在其它情况下则会导致系统性能恶化。

A dual-tone modulation model based on dual-electrode Mach-Zehnder Modulator and nonlinear photodiode is presented,the expressions of fundamental and third-order inter-modulation signals with the non- linear photodiode are derived,the effect of photodiode nonlinearity on third-order inter-modulation distortion is analyzed.The results show that,the PD nonlinearity can suppress the third-order inter-modulation better while appropriate parameters are selected, but in other conditions it deteriorates the system performance.