中文摘要：

传统的光学差频产生的太赫兹辐射转换效率低,不能获得高功率太赫兹辐射。本文对周期极化GaAs晶体中差频产生太赫兹辐射进行了理论计算,通过温度调谐实现了周期极化GaAs晶体中差频获得可调谐太赫兹波的输出。为了提高差频过程的增益和量子效率,在准相位匹配基础上引进了级联差频机理,并对最佳晶体长度和最佳泵浦频率进行了计算。结果表明,利用周期极化的GaAs晶体可以获得更高能量更高效率的太赫兹波辐射。

英文摘要：

The traditional method of optical difference frequency THz radiation with low conversion efficiency can not get high power THz output.In this paper,DFG THz radiation is calculated in quasi-phase-matched（QPM）GaAs.Tunable THz wave is obtained from QPM GaAs crystals using the temperature tuning method.In order to improve the gain of DFG and quantum efficiency,the mechanism of cascaded difference frequency is introduced,and the optimum crystal length and the pump frequency are calculated.It is obviously seen from the results that the terahertz conversion efficiency and the intensity can be greatly enhanced in QPM GaAs.