Multi-octave-spanning supercontinuum generation through high-energy laser filaments in YAG and ZnSe pumped by a 2.4 μm femtosecond Cr:ZnSe laser
Multi-octave-spanning supercontinuum generation through high-energy laser filaments in YAG and ZnSe pumped by a 2.4 μm femtosecond Cr:ZnSe laser
复制标题
通过 2.4 μm 飞秒 Cr:ZnSe 激光器泵浦的 YAG 和 ZnSe 高能激光灯丝产生多倍频程超连续谱
DOI：
10.1017/hpl.2021.1
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发表时间：
2021
影响因子：
4.8
通讯作者：
Hong, Kyung-Han
中科院分区：
文献类型：
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作者：
Nam, Sang-Hoon;Nagar, Garima C.;Dempsey, Dennis;Novák, Ondřej;Shim, Bonggu;Hong, Kyung-Han
我们提出了由 2.4 μm、250 fs Cr:ZnSe 啁啾脉冲激光放大器泵浦的多倍频程超连续谱产生 (SCG) 的高能中红外丝化的实验和数值研究。 SCG 分别在 YAG 和多晶 ZnSe 的反常和正常色散状态下得到了证明。在 6 毫米长的 YAG 介质中，泵浦能量高达 100 μJ，可形成稳定且坚固的单丝以及可见光到中红外 SCG。据作者所知，这是固体中激光灯丝产生的最高能量的多倍频程 SCG。另一方面，在泵浦能量高达 15 μJ 的 6 毫米长多晶 ZnSe 介质中，从单丝中同时观察到基于随机准相位匹配 (RQPM) 的 SCG 和偶次谐波产生。基于单向脉冲传播方程和 RQPM 的数值模拟与测量的多倍频程 SCG 和偶次谐波产生非常吻合。它们还揭示了中红外细丝的时间结构，例如 YAG 中的类孤子自压缩和 ZnSe 中的脉冲展宽。
We present experimental and numerical investigations of high-energy mid-infrared filamentation with multi-octave-spanning supercontinuum generation (SCG), pumped by a 2.4 μm, 250 fs Cr:ZnSe chirped-pulse laser amplifier. The SCG is demonstrated in both anomalous and normal dispersion regimes with YAG and polycrystalline ZnSe, respectively. The formation of stable and robust single filaments along with the visible-to-mid-infrared SCG is obtained with a pump energy of up to 100 μJ in a 6-mm-long YAG medium. To the best of the authors’ knowledge, this is the highest-energy multi-octave-spanning SCG from a laser filament in a solid. On the other hand, the SCG and even-harmonic generation based on random quasi-phase matching (RQPM) are simultaneously observed from the single filaments in a 6-mm-long polycrystalline ZnSe medium with a pump energy of up to 15 μJ. The numerical simulations based on unidirectional pulse propagation equation and RQPM show excellent agreement with the measured multi-octave-spanning SCG and even-harmonic generation. They also reveal the temporal structure of mid-infrared filaments, such as soliton-like self-compression in YAG and pulse broadening in ZnSe.