砷化镓太赫兹光导天线的制备及性能研究

Terahertz Radiation from SI-GaAs Photoconductive Dipole Antenna

用半绝缘砷化镓(SI-GaAs)材料制备了太赫兹(THz)光导天线和天线阵列,其电极间隙分别为50μm、100μm、150μm。用THz时域光谱系统(THz-Time domain system)测试和比较了三种不同电极间隙天线的THz辐射性能,研究了电极间隙的大小对光导天线辐射THz性能影响。实验表明相同衬底材料、几何结构和制作工艺的天线,辐射出的THz电磁波的频谱基本相同,与电极间隙无关;光导天线THz电磁波远场辐射强度与外加偏置电场和天线的有效辐射面积成正比。光导天线阵列在相同的偏置电场以及相同激光光源的情况下比常规光导天线有更强的辐射THz波的能力。

Terahertz（THz） photoconductive antennas and antennas array are prepared with the semi-insulating GaAs materials,whose electrode gap are 50 μm,100μm and 150μm respectively.THz-Time Domain System used to test and compare THz radiation performances of 3 kinds of antennas with different electrode gap.Also,the effect of electrode gaps upon the photoconductive antennas radiation THz performances are studied in this paper.The experiment indicates that the antenna prepared with the same structure material,geometric structure and preparing technology can emit the spectrum of THz electro-magnetic waves and have no relation with electrode gaps.Remote field radiation intensity of photoconductive antenna THz electro-magnetic waves is in positive proportion with the outside additional bias electric field and the antenna effective radiation area.In this case of the same bias electric filed and the same laser power resources,photoconductive antennas array have the stronger radiation THz wave ability than that of the normal photoconductive antennas.