光电导太赫兹天线效率参数的讨论

Discussions on the Efficiency Parameters of THz Photoconductive Antennas

光电导天线是产生太赫兹波最常用的器件之一,但是目前它面临的主要问题是天线效率很低,难以获得高功率的太赫兹波。为了提高其输出功率和效率,介绍了计算光电导天线效率的公式,讨论了影响光电导天线光-太赫兹转换效率的参数:与激光源相关的参数如激光强度、脉冲宽度、激励光斑尺寸及位置;与光电导天线相关的参数如偏压电场、天线材料和几何结构、天线暗电阻率、基底材料等。这对光电导太赫兹天线的分析与设计也是大有裨益的。

Terahertz(THz) photoconductive antennas are one of the most common devices for the generation of THz waves.One of the major problems of the current photoconductive antennas is that the antenna efficiency is very low.This paper introduced a new photoconductive antenna efficiency expression and various parameters of photoconductive antennas are discussed with the aim to improve its optical-THz conversion efficiency factor.Several parameters which are related to optical sources like laser intensity,pulse duration,excitation spot size,location and factors which are connected to photoconductive antennas such as bias field,antenna material and geometry,dark resistivity of antenna and substrate martial have been discussed.The information presented in this paper should be very useful for design and analysis of the performance of photoconductive antennas.