太赫兹波段微腔器件的设计及其特性研究  

Design and characterization of a terahertz microcavity structure

作　　者：马凤英[1] 陈明[1] 刘晓莉[2] 刘建立[1] 池泉[1] 杜艳丽[1] 郭茂田[1] 袁斌[1] 

机构地区：[1]郑州大学物理工程学院,郑州450001 [2]焦作大学机电工程学院,焦作454000

出　　处：《物理学报》2012年第11期261-264,共4页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:60907046);河南省教育厅自然科学研究计划(批准号:2009A140008);河南省青年骨干教师计划资助的课题~~

摘　　要：采用磁控溅射法制备了金属Cr膜,并利用太赫兹时域光谱法获得了其光学参数.利用Cr膜的光学参数计算了其相位穿透深度,设计了基于低温GaAs的全金属平面微腔光电导太赫兹辐射器件.模拟结果表明:器件的谐振频率分别为0.32,0.65,0.98,1.31和1.65 THz,与自由空间的光电导太赫兹谱相比,在谐振频率为0.32 THz处的峰值强度提高了25倍,光谱半高全宽压缩了50倍.讨论了辐射偶极子与腔内驻波场之间的耦合强度对器件辐射强度的影响,发现当辐射中心位于驻波场波腹处时,器件辐射最强,位于波节处时辐射被严重抑制.太赫兹波段微腔效应的研究对于实现单色性好,连续调谐,高效高辐射强度的太赫兹源具有一定的理论意义.The complex refractive indices of the Cr film are obtained by terahertz time-domain spectroscopy. The penetration depth the Cr film is calculated based on the complex refractive indices, and then the effective cavity length and the emitted spectrum of the structure Cr/GaAs/Cr are simulated. The resonant frequencies are located at 0.32, 0.65, 0.98, 1.31 and 1.65 THz, respectively. The peak intensity of the cavity photo-conductive resource at 0.32 THz is 25 times higher than that of non-cavity one and the full width at half maximum is greatly narrowed. The relation between the emitting dipoles and the standing wave field in the cavity is also discussed. The results show that the emission intensity is enhanced when the emitting dipoles are located at the nodes of the standing wave field, but greatly suppressed at antinodes.

关 键 词：平面微腔 金属薄膜 辐射偶极子 太赫兹源 

分 类 号：TN629.1[电子电信—电路与系统]