Yb:YAG thin-disk regenerative amplifier laser system emitting > 500 W average power and and 800-fs long pulses with 50 mJ pulse energy at 1030 nm.

近几十年来，基于近红外激光脉冲下转换的超短THz脉冲相干源取得了巨大的进展。这一进展使时域太赫兹光谱成为一个强大的工具，为各种各样的应用。从物理学和化学中物质基本成分的时间动力学研究，到更应用的主题，如毒品或爆炸物检测。然而，所有这些应用目前都受到持续缺乏发射具有高平均功率的高能THz脉冲的源的强烈限制，特别是在频率区域[1-10 THz]中。 THz-TDS的有限平均功率意味着需要满足THz脉冲能量和重复率之间的不期望的折衷，这反过来意味着要么放弃需要高能脉冲的研究线路，要么在少数情况下牺牲重复率。这些限制的发生是因为大多数THz-TDS设置现在由近红外Ti：Sapphire激光系统驱动，其平均功率仅限于几瓦。由于从近红外到太赫兹的转换效率通常不超过百分之几，因此在太赫兹范围内达到显著更高的平均功率需要以高得多的平均功率驱动超快激光源。（Yb：YAG，1030 nm）系统，该系统基于薄盘激光器技术，提供了高重复率（5 - 50 kHz）和非常高的脉冲能量（高达50 mJ），因此以比它们的Ti：Sa对应物高两个数量级的平均功率（> 500 W）操作。该激光系统一方面将用于探索高重复率下的双色显示，以产生[1-10 THz]区域的宽带和强场太赫兹脉冲，但也可用于在铌酸锂中使用倾斜脉冲前沿产生<1 THz的mJ级THz脉冲。 由于我们目标购买的源的独特性能，我们希望在[1-10 THz区域]实现瓦特级宽带THz脉冲，脉冲能量>1 μJ-据我们所知，在实验室环境中仍然没有配对的性能-以及在< 1 THz区域中以前所未有的高重复率记录高能单周期THz脉冲。这将通过提供更高的脉冲能量来补充我们正在进行的高功率THz源研究，从而实现非线性THz光谱领域的开创性研究，特别是在生物条件下水和其他样品的非线性THz光谱的未探索领域。

Coherent sources of ultrashort THz pulses based on down-conversion of near-infrared laser pulses have seen enormous progress in the last few decades. This progress has enabled time-domain THz spectroscopy to emerge as a powerful tool for a wide variety of applications. ranging from the study of temporal dynamics of fundamental constituents of matter in physics and chemistry, to more applied topics such as drug or explosives detection. However, all these applications are currently strongly limited by the consistent lack of sources emitting energetic THz pulses with high average power, particularly in the frequency region [1-10 THz]. A limited average power of THz-TDS means that an undesired compromise between THz pulse energy and repetition rate needs to be met, which in turn means either abandoning research lines where energetic pulses are needed, or sacrificing repetition rate in the few cases where this is a possibility. These limitations occur because most THz-TDS setups are nowadays driven by near infrared Ti:Sapphire laser systems, which are limited in average power to only few watts. Since the conversion efficiency from near infrared to THz does typically not exceed a few percent, reaching significantly higher average powers in the THz regime requires driving ultrafast laser sources with much higher average power.We are therefore applying here for a state-of-the-art near-infrared ultrafast regenerative laser amplifier (Yb:YAG, 1030 nm) system based on the thin disk laser technology, which provides a unique combination of high repetition rate (5 – 50 kHz) and very high pulse energy (up to 50 mJ), thus operating with two orders of magnitude higher average power (> 500 W) than their Ti:Sa counterparts. This laser system will be used on the one hand for exploring two-color filamentation at high-repetition rate for the generation of broadband and strong-field Terahertz pulses in the [1-10 THz] region, but also for generating mJ-class THz pulses at <1 THz using titled-pulse fronts in Lithium Niobate. Thanks to the unique performance of the source we target to purchase, we expect to achieve watt-level, broadband THz pulses in the [1-10 THz region] with >1 µJ pulse energy - performance which remains unpaired in a laboratory setting to the best of our knowledge - as well as record high-energy single-cycle THz pulses with unprecedented high repetition rate in the < 1 THz region. This will complement our ongoing research on high-power THz sources by providing significantly higher pulse energy, thus enabling groundbreaking research in the field of nonlinear THz spectroscopy, in particular in the unexplored field of nonlinear THz spectroscopy of water and other samples in biological conditions.