中文摘要：

阐述了定向耦合电光开关的基本结构及工作原理，利用耦合模理论和电光调制理论，在1550nm波长下，对器件的结构参量进行了优化，并对其传输光谱、开关电压、插入损耗、串扰等特性进行了分析．模拟过程中，考虑了因金属电极和聚合物材料引起的模式损耗．器件的结构参量优化值为：波导芯截面尺寸为1．7×1．7μm^2，波导芯与电极间的限制层厚度为1．5μm、电极厚度为0．15μm，波导间的耦合间距为2．0μm，相应的耦合长度为2926μm．模拟结果表明，本文所设计的器件在开关转换电压0和17．4V下，在1534到1565nm的波长范围内，器件的插入损耗小于0．16dB，串扰小于-20dB，耦合区在2734～3120μm范围内，器件的插入损耗小于0．22dB，串扰小于-20dB．

英文摘要：

The structure and principle were described for the polymer directional coupler electro-optic switch. In terms of the coupled mode theory and the electro-optic modulation theory, the structural parameters were optimized,and the characteristics were analyzed under the operation wavelength of 1 550 nm,which include the output spectrum, switching voltage, insertion loss and crosstalk. In the simulation, the mode loss caused by the metal electrode and the polymer material were considered. The optimum values of the device as.. the size of the waveguide core is 1.7 × 1.7 μm^2 , the confined layer between the electrode and the core is 1.5μm,the thickness of the electrode is 0.15 μm,the coupling gap between the waveguides is 2.0μm, and the coupling length is 2 926 μm. The simulation results show that under the operation voltage of 0 and 17. 4 V, the insertion loss and the crosstalk are less than 0. 16 dB and -20 dB, respectively,within the range of the wavelength from 1 534 to 1 565 nm;those are less than 0.22 dB and -20 dB,respectively,within the range of the coupling length from 2 734 to 3 120μm. This indicates that the designed device exhibits excellent switching functions.