Extremely strong-field terahertz (THz) radiation in free space has compelling applications in nonequilibrium condensed matter state regulation, all-optical THz electron acceleration and manipulation, THz biological effects, etc. However, these practical applications are constrained by the absence of high-intensity, high-efficiency, high-beam-quality, and stable solid-state THz light sources. Here, the generation of single-cycle 13.9-mJ extreme THz pulses from cryogenically cooled lithium niobate crystals and a 1.2% energy conversion efficiency from 800 nm to THz are demonstrated experimentally using the tilted pulse-front technique driven by a home-built 30-fs, 1.2-Joule Ti:sapphire laser amplifier. The focused peak electric field strength is estimated to be 7.5 MV cm⁻¹. A record of 1.1-mJ THz single-pulse energy at a 450 mJ pump at room temperature is produced and observed that the self-phase modulation of the optical pump can induce THz saturation behavior from the crystals in the substantially nonlinear pump regime. This study lays the foundation for the generation of sub-Joule THz radiation from lithium niobate crystals and will inspire more innovations in extreme THz science and applications.

中文翻译：

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从铌酸锂材料中产生 13.9-mJ 太赫兹辐射

自由空间中的极强场太赫兹 (THz) 辐射在非平衡态凝聚态调节、全光太赫兹电子加速和操纵、太赫兹生物效应等方面具有引人注目的应用。然而，这些实际应用受到缺乏高强度材料的限制。强度、高效率、高光束质量和稳定的固态太赫兹光源。在这里，使用由自制的 30- fs，1.2-Joule Ti：蓝宝石激光放大器。聚焦峰值电场强度估计为 7.5 MV cm ^-1. 在室温下 450 mJ 泵产生了 1.1-mJ THz 单脉冲能量的记录，并观察到光泵的自相位调制可以在基本非线性泵状态下从晶体引起太赫兹饱和行为。这项研究为铌酸锂晶体产生亚焦耳太赫兹辐射奠定了基础，并将激发极端太赫兹科学和应用的更多创新。