砷化镓p-i-n结构中的干扰效应对太赫兹波产生的影响与优化  

Influence and Optimization of Interference Effect in GaAs p-i-n Structure on Terahertz Wave Generation

作　　者：孙长明 李强爽 王婧仪 杜海伟 Sun Changming;Li Qiangshuang;Wang Jingyi;Du Haiwei(School of Measuring and Optical Engineering,Nanchang Hangkong University,Nanchang 330063,Jiangxi,China;Key Laboratory of Nondestructive Testing(Ministry of Education),Nanchang Hangkong University,Nanchang 330063,Jiangxi,China)

机构地区：[1]南昌航空大学测试与光电工程学院,江西南昌330063 [2]南昌航空大学无损检测技术教育部重点实验室,江西南昌330063

出　　处：《中国激光》2023年第22期197-203,共7页Chinese Journal of Lasers

基　　金：国家自然科学基金(12064028);南昌航空大学无损检测技术教育部重点实验室开放基金(EW202108218)。

摘　　要：基于超短激光脉冲泵浦砷化镓(GaAs)p-i-n异质结结构产生太赫兹辐射模型,通过数值模拟和理论分析,研究了干扰效应对产生太赫兹辐射的影响,以及i层厚度与干扰效应之间的相关性。结果显示,干扰效应会降低太赫兹脉冲的强度并使其频谱展宽,而且随着i层厚度的增加干扰效应的影响也在增加,该结果与已有的蒙特卡罗模拟结果相近。数值实验表明,超短激光泵浦GaAs p-i-n结构产生太赫兹脉冲源自于该结构中i层内的载流子振荡,且太赫兹脉冲特性依赖于载流子的浓度分布,干扰效应的影响以及载流子浓度分布依赖于i层厚度。Objective Terahertz wave refers to the electromagnetic wave whose frequency is in the range of 0.1-10 THz(1 THz=1012 Hz)and the wavelength range is 30-3000μm.The terahertz band is located in the transition region between the electronic and optical bands in the entire electromagnetic spectrum,and is also known as the terahertz gap because the research on the terahertz band develops more slowly than those on the electronic and optical bands.Because of its special frequency range,terahertz wave has the characteristics of low photon energy,wide band and high penetration.These excellent characteristics make the terahertz wave have huge applications in the fields of nondestructive testing,communication,spectroscopy,and biomedical imaging.High power broadband terahertz radiation source is the important basis of the practical applications of terahertz wave,so it is of great practical significance to improve the power and bandwidth of terahertz radiation source.At present,photoconductor antenna based on the GaAs semiconductor has been a mature terahertz radiation source.Moreover,some materials pumped by ultrashort laser pulses also can generate broadband terahertz radiation from their surface without the biased electric field.The heterojunction of the semiconductor also can generate broadband terahertz radiation from the surface,such as GaAs p-i-n heterojunction structure.In this paper,the mechanism of terahertz generation from the GaAs p-i-n structure pumped by ultrashort laser pulses is studied.The influence of the interference effect in this process on the terahertz yield and its optimization are discussed based on numerical calculations.Methods Based on the physical model of terahertz radiation generated by the ultrashort laser pumped GaAs p-i-n heterojunction structure,the influence of the interference effect on the terahertz generation is investigated with numerical calculations,and the mechanism of the interference effect is revealed.The influence of the interference effect on terahertz radiation with different th

关 键 词：太赫兹技术 砷化镓 p-i-n异质结结构 干扰效应 

分 类 号：O474[理学—半导体物理]