ZnTe晶体中光学整流产生的THz辐射及其电光探测研究

借助抽运-探测技术研究了ZnTe晶体中光学整流产生的太赫兹(THz)辐射，利用ZnTe晶体的线性电光效应探测THz辐射场分布，观察到了较窄(约为0.2 ps)的THz场分布及相应较宽(响应超过4 THz，半峰宽约为2.4 THz)的THz频谱，并运用琼斯矩阵对实验结果进行了理论拟合. 研究了飞秒激光脉冲波长(750—850 nm)、脉冲宽度(56—225 fs)和晶体旋转与THz辐射产生的关系. 同时改变探测光偏振方向进行偏振调制，并从理论上分析了偏振调制对THz辐射探测的影响. 关键词： THz辐射 光学整流 电光探测 ZnTe

Generation of terahertz radiation via optical rectification and electro-optic detection in ZnTe crystals

We report on the generation of terahertz (THz) radiation via optical rectification and the detection using electro-optic sampling in <110> ZnTe crystal by the pump-probe technique. The pulsewidth of the observed THz radiation is about 0.2 ps, resulting in the wideband THz spectra with a spectral sensitivity beyond 4 THz and the full width at half-maximum of about 2.4 THz. The Jones matrix method has been employed successfully for the calculation of the THz radiation. We study the effects of the optical pulse wavelength, pulsewidth and the ZnTe crystal <001> axis on the generation of THz radiation in the ZnTe crystal. The dependence of the polarization-modulation on the THz detection has also been investigated both experimentally and theoretically by changing the polarization of the probe light.