交叉耦合效应对M-Z调制器谐波抑制比的影响

Influence of Cross Coupling Effect on Harmonic Suppression Ratio of M-Z Modulator

摘要:

针对微波光子链路低噪声高线性度的应用需求,研究了Mach-Zehnder (M-Z)型电光调制器波导交叉耦合效应对谐波抑制比的影响。首先通过OptiBPM和MATLAB联合仿真发现波导间交叉耦合效应会导致调制器射频电极与偏置电极工作点的偏移,进而降低谐波抑制比；其次利用特制的窄波导间距铌酸锂调制器实测验证了该现象,最后提出了一种能快速检测M-Z型电光调制器交叉耦合效应的方法。文章不仅探索了波导结构对谐波抑制比的影响,还为用于微波光子技术的脊波导及光子晶体薄膜铌酸锂调制器的研制提供了一定参考。

Abstract:

For the application of low noise and high linearity in microwave photonic link, the influence of waveguide cross coupling effect of M-Z electro-optic modulator on harmonic suppression ratio was studied. Firstly, through the joint simulation of OptiBPM and MATLAB, it was found that the cross coupling effect between waveguides led to a shift of the modulator RF electrode and bias electrode operating point, and then reduced the harmonic suppression ratio. Secondly, the phenomenon was verified by a special lithium niobate modulator. At last, a method to detect the cross coupling effect of M-Z electro-optic modulator was proposed. This discovery not only breaks the blind area of the influence of waveguide structure on harmonic suppression ratio, but also provides a certain reference for the development of ridge waveguide and photonic crystal thin film lithium niobate modulator for microwave photonic technology.