设计了一种基于绝缘上层硅的硅-有机物材料混合马赫-曾德干涉型高速电光调制器.利用光束传播法对顶层硅为220 nm的绝缘上层硅基片上的3 dB分束器/合束器的结构参数进行模拟,优化后附加损耗仅为0.106 dB.为提高模式转换效率, 在条形波导和slot波导之间设计了模式转换器, 光耦合效率高达98.8%, 实现了光模式高效转化.利用时域有限差分法模拟了slot波导平板区掺杂浓度对波导内光学损耗的影响, 在几乎不产生光学损耗的情况下, 得到平板区轻掺杂浓度为71017/cm3, 调制器设计总损耗为0.493 dB.利用薄膜模式匹配法对slot波导结构进行仿真分析, 考虑slot区等效电容及平板区等效电阻对带宽的影响, 优化后得到slot波导结构的限制因子为0.199.采用slot波导与强非线性有机材料LXM1结合的绝缘上层硅平台实现了强普克尔效应, 得到电光调制器半波电压长度积为1.544 V·mm, 电学响应3 dB带宽为137 GHz.

A push-pull high-speed silicon-organic hybird Mach-Zahnder interference electro-optic modulator was designed based on silicon on insulator. By using beam propagation method, the structure of 3 dB beam splitter/beam combiner on the silicon on insulator (top silicon thickness is 220 nm) has been simulated optimally whose insertion loss is 0.106 dB. Mode converter was designed between stripe waveguide and slot waveguide to realize an efficient transformation of optical transmission mode, and the coupling efficiency is as high as 98.8% . Also, the influence of doping concentration of slot waveguide slab area on optical loss of slot waveguide was analyzed by using finite-difference time domain method when the doping concentration is 7×1017/cm3, the optical loss is nearly zero. The total loss of the modulator is 0.493 dB. Considering the effect of slot waveguide equivalent capacitance and slab area equivalent resistance on the bandwidths, the waveguide structure was simulated by film mode matching solver and the optical field confinement factor can be optimized to 0.199. The ultrafast pockels effect was exploited by using the silicon-organic hybird platform, which combines highly nonlinear organic materials with slot waveguides, and realizes a voltage-length of 1.544 V·mm and a bandwidth of 137 GHz.