加载方形开口谐振环的太赫兹光电导天线性能仿真分析  

Simulation and Analysis of Performance of Terahertz Photoconductive Antenna with Square Split-Ring Resonators

作　　者：熊中刚 尚丽平[2] 邓琥[2] 陈林宇 杨洁萍 郭进[2] 李桂琳 Xiong Zhonggang;Shang Liping;Deng Hu;Chen Linyu;Yang Jieping;Guo Jin;Li Guilin(School of Mechanical Engineering,Guilin University of Aerospace Technology,Guilin,Guangxi 541004,China;School of Science,Southwest University of Science,Mianyang,Sichuan 621010,China)

机构地区：[1]桂林航天工业学院机械工程学院,广西桂林541004 [2]西南科技大学信息工程学院,四川绵阳621010

出　　处：《中国激光》2021年第16期224-233,共10页Chinese Journal of Lasers

基　　金：国防基础科研项目(JCKY2018404C007);四川省科技厅重点研发项目(2019YFG0114);广西科技厅自然科学基金(2019GXNSFBA185013);广西教育厅科研项目(2019KY0812)。

摘　　要：对偶极子天线加载方形开口谐振环所构成的太赫兹微结构光电导天线性能展开分析研究。在偶极子天线的基础模型上,基于耦合波理论描述微结构共振模式在入射光和微结构相互作用下振幅的动力学过程;通过调整结构参数模拟分析太赫兹波与结构间的局域耦合特性关系,仿真对比偶极子和微结构光电导天线参数与太赫兹辐射时域脉冲波形和频谱特性关系,以及偶极子天线与微结构天线辐射方向的仿真结果。研究结果表明,随着天线结构参数,如极间间隙的增大,结构间的耦合系数逐步增大,耦合强度逐渐增加,产生的局域电磁共振模式使共振频率处的电磁能量得到极大增强。调整长度、宽度和极间间隙获得最佳结构参数,使最大辐射强度提高了340%,共振峰值逐步发生频移,频率移动范围为0.2~0.8 THz。Objective With the rapid development of terahertz(THz)technology,requirements for THz radiation sources and detectors have increased.Currently,the high refractive index of photoconductive materials decreases the photoelectric conversion efficiency and the shielding effect of the field leads to the saturation of the radiated power,thereby limiting further improvement of the radiated power of THz sources.Therefore,the study on high-power broadband THz radiation sources is an active field in THz-related technology.Many researchers have conducted several studies on the photoconductive antenna(PCA)optimization design because PCA is one of the most widely used THz radiation sources.The THz radiation performance of PCA can be effectively adjusted by improving the antenna structure,which can further promote the wide application of THz devices.Methods Herein,the performance of a THz-microstructured PCA based on the dipole PCA with embedded square split-ring resonators is analyzed and investigated.Based on the model of dipole PCA,the dynamic process of the amplitude of the designed microstructure resonance mode under the interaction of incident light and structure is described using the coupling wave theory.The local coupling characteristics between the THz wave and structures are simulated and analyzed by adjusting the structural parameters.Furthermore,the relationships of the time domain pulse waveform and frequency spectrum characteristics of THz radiation between the parameters of the dipole and microstructured PCAs are simulated and compared.Finally,the simulation results of the radiation direction of the dipole and microstructured PCAs are compared.Results and Discussions In this design,the square split-ring resonator(Fig.1(b))is embedded in the dipole PCA electrode(Fig.1(a))to investigate the interaction between the microstructured PCA and pumped laser,which is incident vertically on the surface gap of the structure.In the simulation,three resonance frequency curves under different effects of local electromagnetic m

关 键 词：物理光学 太赫兹 光电导天线 时域耦合波模型 辐射性能 方形开口谐振环 

分 类 号：TN201[电子电信—物理电子学]