School of Electronic and Information Engineering, and School of Cyber Science and Technology, Beihang University, Beijing, 100191, China.
Zhangjiang Laboratory, 100 Haike Road, Shanghai, 201210, China.
Adv Mater. 2023 Jun;35(23):e2208947. doi: 10.1002/adma.202208947. Epub 2023 Apr 27.
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 . 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.
在自由空间中，超强太赫兹（THz）辐射在非平衡凝聚态物质状态调控、全光太赫兹电子加速和操控、太赫兹生物效应等方面具有重要的应用。然而，这些实际应用受到缺乏高强度、高效率、高质量光束和稳定的固态太赫兹光源的限制。在这里，我们通过使用倾斜脉冲前沿技术，利用自制的 30 飞秒、1.2 焦耳钛宝石激光放大器，从深制冷的铌酸锂晶体中实验产生了单周期 13.9 毫焦耳的极端太赫兹脉冲，其 800nm 到太赫兹的能量转换效率为 1.2%。聚焦后的峰值电场强度估计为 7.5MV/cm。在室温下，我们产生了 450mJ 泵浦光的 1.1 毫焦耳太赫兹单脉冲能量的记录，并且观察到光泵浦的自相位调制可以在实质上的非线性泵浦状态下诱导太赫兹饱和行为。本研究为从铌酸锂晶体产生亚焦耳太赫兹辐射奠定了基础，并将激发更多的太赫兹极端科学和应用方面的创新。
