A continuously tunable, energy-enhanced injection, pulse-seeded THz parametric generator based on a KTP crystal (KTP ips-TPG) has been demonstrated in this paper. Theoretical analysis denotes that improving the initial Stokes intensity is favorable to achieve a continuously tunable, high-energy THz generation in a KTP crystal, which is clarified to originate from the enhancement of stimulated polariton scattering (SPS) process in the photon-like region of polariton and parametric amplification process in the phonon-like region of polariton. In the experiment, the THz continuously tunable range was from 2.93 to 6.21 THz, and the THz energies were 6.27, 2.62, 5.43, 4.59, and 5.88 μJ at the output peaks of 3.33, 3.83, 4.41, 4.85, and 5.69 THz, respectively. Compared with the traditional KTP THz parametric oscillator (KTP TPO) with discontinuous frequency tuning, the KTP ips-TPG has great improvement in terms of continuous frequency tuning range and THz output energy, where the enhancement ratios of THz output energy were 6.88× at 3.36 THz, 5.25× at 4.35 THz, 18.21× at 4.79 THz, and 1.82× at 5.69 THz. This injection pulse-seeded THz parametric source based on a KTP crystal is not only suitable to the practical applications in THz high frequency range, but also provides a technical solution for the KTP-family crystals to achieve a continuously tunable and high energy THz generation in a wide THz region.

中文翻译：

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基于KTP晶体的连续可调能量增强注入脉冲种子太赫兹参量发生器

本文展示了一种基于 KTP 晶体 (KTP ips-TPG) 的连续可调、能量增强注入、脉冲种子太赫兹参量发生器。理论分析表明，提高初始斯托克斯强度有利于在 KTP 晶体中实现连续可调的高能太赫兹产生，这被澄清源于类光子区域中受激极化子散射（SPS）过程的增强。极化子的类声子区域中的极化子和参数放大过程。实验中，太赫兹连续可调范围为2.93～6.21 THz，输出峰值分别为3.33、3.83、4.41、4.56 THz、5.89 THz、THz能量分别为6.27、2.62、5.43、4.59、5.88 μJ。 . 与传统的非连续频率调谐的KTP THz参量振荡器（KTP TPO）相比，KTP ips-TPG在连续频率调谐范围和太赫兹输出能量方面都有很大的改进，其中太赫兹输出能量的增强比为6.88×3.36太赫兹，4.35 太赫兹时为 5.25 倍，4.79 太赫兹时为 18.21 倍，5.69 太赫兹时为 1.82 倍。这种基于KTP晶体的注入脉冲种子太赫兹参量源不仅适用于太赫兹高频范围的实际应用，而且为KTP系列晶体实现连续可调和高能太赫兹产生提供了技术解决方案。宽的太赫兹区域。4.35 THz 时为 25×，4.79 THz 时为 18.21×，5.69 THz 时为 1.82×。这种基于KTP晶体的注入脉冲种子太赫兹参量源不仅适用于太赫兹高频范围的实际应用，而且为KTP系列晶体实现连续可调和高能太赫兹产生提供了技术解决方案。宽的太赫兹区域。4.35 THz 时为 25×，4.79 THz 时为 18.21×，5.69 THz 时为 1.82×。这种基于KTP晶体的注入脉冲种子太赫兹参量源不仅适用于太赫兹高频范围的实际应用，而且为KTP系列晶体实现连续可调和高能太赫兹产生提供了技术解决方案。宽的太赫兹区域。