拍瓦级光参量啁啾脉冲放大系统中光参量相位演化研究  

Investigation on Optical Parametric Phase Evolution in Petawatt Optical Parametric Chirped Pulse Amplifier System

作　　者：李纲[1] 周凯南[1] 朱斌[1] 谢娜[1] 卢峰[1] 蒋东镔[1] 郭仪[1] 黄征[1] 孙立[1] 杨雷[1] 巫殷忠[1] 刘红杰[1] 粟敬钦[1] Li Gang;Zhou Kainan;Zhu Bin;Xie Na;Lu Feng;Jiang Dongbin;Guo Yi;Huang Zheng;Sun Li;Yang Lei;Wu Yinzhong;Liu Hongjie;Su Jingqin(Science and Technology on Plasma Physics Laboratory,Research Center of Laser Fusion,China Academy of Engineering Physics,Mianyang 621900,Sichuan,China)

机构地区：[1]中国工程物理研究院激光聚变研究中心等离子体物理科学与技术实验室,四川绵阳621900

出　　处：《中国激光》2024年第6期30-38,共9页Chinese Journal of Lasers

基　　金：中国工程物理研究院国防科技等离子体物理重点实验室研究基金(6142A04210104,JCKYS2021212007);中国工程物理研究院创新发展基金(CX20200022)。

摘　　要：在基于光参量啁啾脉冲放大的拍瓦级超短超强飞秒激光装置中,光参量相位是阻碍脉冲时域压缩的关键因素。对中国工程物理研究院的数拍瓦全光参量啁啾脉冲放大装置(SILEX-II)的光参量相位演化进行了详细研究。研究结果表明,通过光参量放大过程累积的群延迟色散高达532 fs2,三阶色散高达5782 fs3,在未补偿光参量相位的情况下,压缩脉冲的时域峰值强度仅为傅里叶变换极限脉冲的43%。通过调节压缩器光栅间距,补偿了光参量相位的群延迟色散,将压缩脉冲的时域峰值强度增加至傅里叶变换极限脉冲的94%。研究结果为SILEX-II激光装置的脉冲时域压缩提供了有效指导,同时也为未来基于全光参量啁啾脉冲放大技术的10~100 PW高峰值功率激光器的设计提供了依据。Objective In contrast to traditional lasers utilizing chirped pulse amplification(CPA),such as Ti∶sapphire,amplified signal pulses from optical parametric chirped pulse amplification(OPCPA)inherently experience excess spectral phase distortions during the parametric amplification process besides the linear phase accumulated from crystal dispersion.These excess spectral phase distortions,also known as optical parametric phases(OPP),represent a significant issue that impedes pulse compression in petawattlevel OPCPA laser systems.With this in mind,the present study seeks to examine the evolution of OPP in the SILEX-II all-OPCPA multi-PW laser facility,developed at the Laser Fusion Research Center of the China Academy of Engineering Physics(CAEP).Analytical and numerical calculations are carried out to determine the total group delay dispersion(GDD)and third-order dispersion(TOD)induced by the OPP,from the high-intensity picosecond pulse-pumped front-end to high-energy nanosecond pulse-pumped power amplifiers.These findings are expected to provide valuable insights for the temporal compression of the SILEX-II laser system and inform the design of high-peak-power laser systems(from 10 PW to 100 PW)utilizing OPCPA technology.Methods The OPCPA process is modeled using the classical coupled-wave equations[Eq.(3)],under the assumption of a slowly varying electric field envelope.This model is numerically solved using the split-step Fourier algorithm.The focus of this study is exclusively on the OPCPA process and evolution of OPP.Consequently,it is assumed that the initial pulse entering the OPCPA only carries a GDD,which stretches the signal in the time domain to match the pump pulse.The evolution of the OPP is deduced by subtracting the initial GDD and the material dispersion of the parametric crystal from the spectral phase of the amplified pulse.The numerical results are compared with the analytical ones,obtained using Eq.(1)for both high-intensity picosecond pulse-pumped frontend and high-energy nanosecond pulse-pump

关 键 词：激光器 光参量啁啾脉冲放大 光参量相位 时域压缩 傅里叶变换极限脉冲 

分 类 号：O437.4[机械工程—光学工程]