基于超短激光脉冲泵浦砷化铝镓多层异质结构的宽带太赫兹辐射产生研究  

Investigation on broadband terahertz generation based on ultrashort laser pumped AlGaAs multilayer heterostructure

作　　者：孙长明 李强爽 杜海伟 吴涛 伏燕军[1,2] SUN Chang-Ming;LI Qiang-Shuang;DU Hai-Wei;WU Tao;FU Yan-Jun(School of Measuring and Optical Engineering,Nanchang Hangkong University,Nanchang 330063,China;Key Laboratory of Nondestructive Testing(Ministry of Education),Nanchang Hangkong University,Nanchang 330063,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：《红外与毫米波学报》2023年第4期497-503,共7页Journal of Infrared and Millimeter Waves

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开放基金(EW202108218)。

摘　　要：半导体异质结构具有良好的束缚载流子的能力与产生大功率太赫兹辐射的潜力。但由于异质结构中等离子体非相干振荡的干扰效应造成了太赫兹辐射强度的大幅度降低,因此能够在基于砷化铝镓(Al_(x)Ga_(1-x)As)多层异质结构并通过调节其中铝的摩尔分数来调节窄带隙层的吸收系数,从而使得异质结构每一个窄带隙层的激发载流子数目大致相同,达到几乎完全消除干扰效应的目标。基于砷化铝镓多层异质结构的太赫兹辐射产生模型,结合数值计算研究了宽带太赫兹辐射的输出特性,获得泵浦激光脉冲宽度与产生的太赫兹脉冲之间的定量关系,并分析了泵浦激光脉冲参数对产生的太赫兹脉冲各项参数的影响。本项研究为开展半导体材料与器件相关的宽带太赫兹辐射源提供了一定的理论参考。Semiconductor heterostructures have great ability to bind carriers and the potential to produce high power terahertz radiation.However,the intensity of terahertz radiation is substantially reduced,due to the interference effects of incoherent oscillations of plasma in the heterostructure.Thus in the AlGaAs(Al_(x)Ga_(1-x)As)multilayer heterostructure,it is able to adjust the absorption coefficient of the narrow band-gap layer by adjusting the aluminum molar fraction,which makes the excitation carriers number in each narrow band-gap layer approximately the same,achieving the goal of almost completely eliminating the interference effects.Based on the AlGaAs multilayer heterostructure terahertz radiation model,the properties of broadband terahertz radiation are studied with the numerical calculations,the quantitative relationships between the pump laser pulse width and the generated terahertz pulse are obtained,and the influence of pump laser pulse parameters on the parameters of generated terahertz pulse is also analyzed.This study provides a reference for the development of broadband terahertz radiation sources based on the semiconductor.

关 键 词：多层异质结构 太赫兹 数值计算 砷化铝镓 

分 类 号：O474[理学—半导体物理]