Xu Bingfeng, Wang Yuye, Sun Yue, Zhang Jingxi, Zhang Feng, Xu Degang, Yao Jianquan
Opt Express. 2025 Feb 10;33(3):6331-6342. doi: 10.1364/OE.544277.
A high-repetition-rate and high-peak-power terahertz parametric source based on the stimulated polariton scattering in MgO: LiNbO crystal has been demonstrated using an electro-optic Q-switched nanosecond Nd: YAG laser. The high-repetition-rate 1064 nm pump laser under 1 kHz was built with a L-shape cavity, where the maximum average power reaches 7.26 W with the pulse width of 12 ns. By optimizing the diameters and position of pump beam waist in MgO: LiNbO crystal, the maximum average THz-wave output power reaching 29.69 µW has been obtained at 1.78 THz, corresponding to the THz-wave peak power of 4.2 W. The tunable THz-wave frequency was in the range of 1.06-3.18 THz. The THz-wave beam quality factor M was estimated to be 1.81 × 4.32 in the and directions, respectively. Furthermore, this THz parametric source is used to characterize KDP and its deuterated counterpart DKDP crystals. A clear fingerprint peak was observed at 2.3 THz in DKDP but not in KDP. This work demonstrates the potential of this THz parametric source's potential in characterizing and imaging crystalline materials with subtle structural variation.
基于MgO:LiNbO晶体中受激极化激元散射的高重复率、高峰值功率太赫兹参量源已通过电光调Q纳秒Nd:YAG激光器得到验证。采用L型腔体构建了1kHz以下的高重复率1064nm泵浦激光器，其最大平均功率达到7.26W，脉冲宽度为12ns。通过优化MgO:LiNbO晶体中泵浦光束腰斑的直径和位置，在1.78THz处获得了最大平均太赫兹波输出功率29.69µW，对应太赫兹波峰值功率4.2W。太赫兹波频率可调范围为1.06 - 3.18THz。太赫兹波束质量因子M在x和y方向上分别估计为1.81×4.32。此外，该太赫兹参量源用于表征KDP及其氘代对应物DKDP晶体。在DKDP中于2.3THz处观察到清晰的指纹峰，而在KDP中未观察到。这项工作展示了该太赫兹参量源在表征和成像具有细微结构变化的晶体材料方面的潜力。
