超宽带聚合物调制器的优化设计

Design and Optimization of the Ultra-Broadband Polymer Optical Modulator

设计了一种以聚合物作为材料的低损耗、宽带宽的Mach-Zehnder光波导调制器。分析了调制器的脊波导的模式特性,设计了脊波导的结构,并使用BPM软件模拟了脊形波导的光场分布;通过对光场分布的分析,优化了脊形波导的宽度W_g,脊高b,芯层高度H。同时对聚合物调制器的电极进行了优化,包括电极宽度W和电极间距D,使得调制器有较小的导体损耗以及较好的阻抗匹配。并结合了脊波导的结构参数和电极的优化参数,给出了优化结果,它能够使微波的有效折射率与光波的有效折射率达到匹配,从而使带宽达到1 77 GHz,导体损耗为0.256 9 dB/cm·GHz^(?)。

A low loss and wide bandwidth Mach Zehnder modulator is designed which is based on the polymer material. The mode characteristic is analyzed and the ridge waveguide is designed. Optical field distribution is simulated by the software of Beam Propagation Method （BPM）. During the analysis, parameters of the ridge waveguide are optimized, including the width Wg, the rib height b, and the total core height H. Aiming at a smaller conductor loss and better impedance match, the structure parameters of electrode are also optimized. Combining with the parameters of the ridge waveguide and the electrode, velocities match between lightwave and microwave can be achieved, an ultra-broadband of 177 GHz and low conductor loss of 0. 256 9 dB/cm ·GHz1/2 are well designed.