亚微米硅基波导光学相位调制器的优化分析

Optimization and Analysis for Submicrometermeter-Scale Silicon Waveguide Optical Phase Modulator

建立了基于注入式PIN结构的亚微米硅基波导光学相位调制器模型,对该调制器模型的光学特性和电学特性进行了理论分析和仿真,确定了器件的单偏振单模条件。在此条件下,重点分析并讨论了在不同结构参数与掺杂条件下器件调制效率的变化特性。结果表明,通过减小外脊高、增大掺杂浓度、减小波导区到掺杂区的距离、增大掺杂深度等均可有效提高器件的调制效率。在此基础上确定了器件的最优结构参数,结果表明其相位调制效率可达到19rad·V-1·mm-1,3dB带宽大于1GHz,同时该调制器还具有结构紧凑、工作电压低、易于集成的优点。

The theoretical model of a carrier-injection-PIN-based submicrometer-scale silicon waveguide optical phase modulator is built. The optical and electrical properties of the modulator are analyzed theoretically, and the conditions of single-polarization and single-mode for the submicrometer-scale waveguide are determined based on the theoretical model. The effects of structure dimensions and doping conditions on modulation efficiency are discussed emphatically under the single-polarization and single-mode conditions. The analysis shows that modulation efficiency can be improved effectively by reducing slab height, increasing doping concentration, increasing doping depth and reducing distance between the doped regions and the rib edge. The optimized device scheme is presented based on the analysis results. The excellent optical mode overlap with the refractive index change region, together with the submicrometer-scale waveguide, enables the modulation efficiency of 19 rad·V^-1·mm^-1 , the modulation bandwidth beyond 1 GHz, and the advantages of compactness, low voltage and ease of integration.