低半波电压铌酸锂薄膜电光调制器仿真与分析  

Simulation and analysis of low half-wave voltage lithium niobate thin film electro-optical modulator

作　　者：王生水 魏朝阳[2] 姜晨[1] 高睿 万欣 WANG Shengshui;WEI Chaoyang;JIANG Chen;GAO Rui;WAN Xin(School of Mechanical Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China)

机构地区：[1]上海理工大学机械工程学院,上海200093 [2]中国科学院上海光学精密机械研究所,上海201800

出　　处：《上海理工大学学报》2021年第5期452-459,共8页Journal of University of Shanghai For Science and Technology

摘　　要：针对铌酸锂薄膜Mach-Zehnder电光调制器存在半波电压较大的问题,采用有限元法对方向耦合器耦合模理论进行分析,并对电光调制器的关键结构参数进行优化设计。结果表明:两干涉臂光功率差与波导耦合长度呈正弦函数分布,最小波导耦合长度随耦合间距的增大而增大。在调制臂长度为2 cm,光波长为1550 nm时,仿真计算的半波电压值Vπ为0.9 V,半波电压长度积为1.8 V·cm,消光比达到26 dB。通过调制臂截面分析,得到静电场分量Ex,电位移矢量Dx,以及光模分布,并计算出电光重叠积分因子Γ为0.586。基于上述仿真结果,与以往现有的电光调制器的半波电压(1.4~10.2 V)相比,经优化后的电光调制器的半波电压更低,进而使器件的功耗更低,有利于大规模光电集成。In view of the large half-wave voltage of the lithium niobate thin film Mach-Zehnder electro-optical modulator,the finite element method was used to analyze the coupled mode theory of the directional coupler in detail,and the key structural parameters of the electro-optical modulator were optimized.The results show that the optical power difference between the two interference arms and the coupling length of the waveguide present a sine function distribution,and the minimum coupling length of the waveguide increases as the coupling distance increases.When the modulation arm length is 2 cm and the light wavelength is 1550 nm,the half-wave voltage Vπcalculated by the simulation is 0.9 V.The half-wave voltage length product is 1.8 V·cm,and the extinction ratio reaches 26 dB.Through the cross-section analysis of the modulation arm,the electrostatic field component Ex,the electric displacement vector Dx,and the optical mode distribution are obtained,and the electro-optical overlap integral factorΓis calculated to be 0.586.Based on the above simulation results,compared with the half-wave voltage(1.4~10.2 V)of the existing electro-optical modulator,the optimized electro-optical modulator has a lower half-wave voltage.This in turn makes the device power consumption lower,conducive to large-scale optoelectronic integration.

关 键 词：半波电压 铌酸锂薄膜 电光调制器 有限元法 方向耦合器 光波导 

分 类 号：TN256[电子电信—物理电子学]