基于LiNbO3光整流效应的高峰值功率太赫兹源

High-peak-power terahertz pulses generated by optical rectification in LiNbO3

摘要:

基于光整流效应，通过倾斜泵浦光波前(TPFP)在铌酸锂晶体中实现相位匹配，是一种有效的产生太赫兹辐射的方法。建立了一种更完备的基于波面倾斜的产生太赫兹波的理论模型，用于分析不同泵浦光偏振下产生太赫兹波的转换效率。搭建了基于铌酸锂晶体光整流效应的高峰值功率太赫兹源和太赫兹时域光谱系统，并利用太赫兹面阵探测器对获得的太赫兹辐射进行了分析。结果表明，所获得的太赫兹辐射单脉冲峰值功率达到0.56 MW，频谱宽度为0.1 THz~2 THz，转换效率为0.56‰，与理论模拟结果相符。

Abstract:

Optical rectification of laser pulses in LiNbO3 by Tilted-Pulse-Front Pumping(TPFP) to fulfill phase match is a powerful way to generate terahertz pulses. A more detailed theoretical model for TPFP scheme is presented, which then is used to analyze the terahertz generation efficiency under different pump beam polarization states. A setup to generate high-peak-power terahertz pulses by optical rectification in LiNbO3 and a time domain spectroscopy system are established. The property of generated terahertz pulses is analyzed by using terahertz camera, and the results indicate that the peak power of terahertz pulses with 0.1 THz-2 THz frequency is 0.56 MW, and the generation efficiency is 0.56‰, which is consistent with the calculated result.