基于金属阵列等离子体共振增强的太赫兹光电导天线设计

针对传统太赫兹光电导天线输出功率较低的问题,设计了一种基于金属阵列等离子体共振增强的太赫兹光电导天线,以提高太赫兹光电导天线的输出功率。通过对电磁波和半导体的物理场进行了理论分析,并建立了太赫兹光电导天线模型,利用COMSOL多物理场有限元软件进行了仿真实验研究。仿真计算了金属阵列等离子体共振增强结构不同周期宽度与高度下半导体基底对800 nm激光的光吸收量,得到了一种优化的金属阵列等离子体共振增强结构,然后计算该结构的太赫兹光电导天线的光电流,同时仿真计算了传统太赫兹光电导天线的光电流。研究结果表明:设计得到的金属阵列等离子体共振增强太赫兹光电导天线比传统太赫兹光电导天线光电流增强了约20倍,为等离子体共振增强的太赫兹光电导天线提供了依据。

Enhanced terahertz photoconductive antenna based on metal-array plasmon resonance

Aiming at the low output power of conventional terahertz photoconductive antenna, a terahertz photoconductive antenna based on metal-array plasmon resonance enhancement was designed to improve the output power of terahertz photoconductive antenna. The physical field of electromagnetic wave and semiconductor were analyzed theoretically and the terahertz photoconductive antenna model was established. The simulation experiment was carried out by COMSOL multiphysics finite element software. The optical absorption of the 800 nm laser at dif-ferent pitches and heights of the metal-array plasmon resonance structure was calculated and the optimized structure of the plasmon resonance enhancement structure was obtained. Then the photocurrent of this designed plasmon resonance terahertz photoconductive antenna was calcu-lated, as well as the conventional terahertz photoconductive antenna. The results indicate that the designed metal-array plasmon resonance enhanced terahertz photoconductive antenna is about 20 times stronger than that of the conventional terahertz photoconductive antenna, which provided the basis for the enhancement of plasmon resonance terahertz photoconductive antenna.