基于FDTD的偶极子电场传感器幅频特性分析

Analysis on Amplitude-frequency Characteristics of Integrated Optical Waveguide Electric Field Sensor with Dipole Electrodes by FDTD

介绍了时域有限差分(FDTD)法的理论与基本原理。利用该方法,得到了可对集成光波导偶极子电场传感器幅频特性进行理论分析的数学表达式。为优化器件性能,利用仿真,对在低频与高频电磁波入射时,不同电极长度/宽度下的器件幅频特性进行了比较。结果表明,低频电磁波入射时,采用较长或较窄的电极,均可提高器件的响应幅度;改变电极长度与宽度,对器件响应频率几乎没有影响。高频电磁波入射时,采用较长或较窄的电极,器件同样可获得较大的响应幅度;改变电极宽度,对器件响应频率的影响很小,但较长的电极会显著降低器件的响应频率。

The theories and basic principles of Finite Difference Time Domain（FDTD） are described.This method is applied to obtain the expressions,which can be utilized to analyze the amplitude-frequency characteristics of integrated optical waveguide dipole electrodes electric field sensor.The sensor performance at low/high frequencies input electromagnetic waves,with different electrode lengths/widths are compared by simulations.The results reveal that,when input wave is at low frequency,sensor amplitude characteristic can be improved with a large electrode length or a small electrode width;changing electrode length and width almost have no influence on sensor＇s response frequency.When input wave is at high frequency,sensor can also obtain large response amplitude with a long/narrow electrode;changing electrode width causes a little influence on sensor＇s response frequency,however,its response frequency is obviously debased by a long electrode.