基于宽、窄带和频法的超辐射光三倍频仿真  

Numerical Simulation on Third-Harmonic Generation of Super-Luminescent Light by Mixing Broadband and Narrowband Lasers

作　　者：章旭 季来林[2] 刘栋[2] 高妍琦[2] 隋展 赵晓晖 向霞 Zhang Xu;Ji Lailin;Liu Dong;Gao Yanqi;Sui Zhan;Zhao Xiaohui;Xiang Xia(School of Physics,University of Electronic Science and Technology of China,Sichuan 610054,China;Shanghai Institute of Laser Plasma,China Academy of Engineering Physics,Shanghai201800,China)

机构地区：[1]电子科技大学物理学院,四川成都611731 [2]中国工程物理研究院上海激光等离子体研究所,上海201800

出　　处：《中国激光》2021年第21期129-136,共8页Chinese Journal of Lasers

基　　金：国家自然科学基金(11804321,12074353)、科学挑战计划(TZ2016005)。

摘　　要：高效宽带的三次谐波转换是激光惯性约束聚变驱动器的关键技术之一。超辐射光的宽带特性以及宽、窄带和频方案为这一研究提供了新的实现途径。本文基于超辐射光特性,建立了其三倍频过程数值计算模型,并分析了时间高相干基频光与超辐射倍频光和频的效率和光谱特性演化。与超辐射光直接三倍频相比,宽、窄和频方案能够有效地减小群速度失配对超辐射光三倍频效率的影响,可以将超辐射光三倍频效率提升至44%,输出三倍频带宽可达到1.9 THz,该结果可指导超辐射光三倍频系统的设计与相关实验研究。Objective High-efficiency broadband third-harmonic conversion is one of the key technologies of laser inertial confinement fusion driver.In the research of laser-driven inertial confinement fusion(ICF),neodymium glass laser frequency tripling(351 nm)is generally used to target to effectively improve the coupling efficiency of laser and plasma.At the same time,further increase the relative bandwidth(Δν/ν)of the laser to~1%,which can effectively suppress the increase in instability during the interaction between the laser and the plasma,and reduce the generation of backward stimulated scattering and hot electrons.However,on account of high-speed optical field modulation technology,narrow gain during high-gain amplification,and narrow high-efficiency frequency tripling bandwidth,the current output bandwidth of the laser driver is not greater than 0.3 nm(100 GHz).The broadband characteristics of super luminescent light and the wide,narrowband and frequency schemes provide a new way to realize this research.Methods A numerical solution method for the harmonic conversion process under high power conditions is deduced.The necessity of studying super luminescent light is analyzed,and according to literature,a numerical model of super luminescent light is built,and combined with the numerical model of super luminescent light,the coupled wave equation for numerical simulation of the frequency tripling process of super luminescent light is given.The thickness of frequency doubling crystal and frequency tripling crystal is optimized to obtain the optimal solution under corresponding conditions.It also analyzes the evolution of the efficiency and spectral characteristics of the narrow-band light with high time coherence as the sum frequency of the fundamental frequency light and the super luminescent light frequency doubled light.In addition,the direct frequency tripling process of super luminescent light,and the wide,narrowband sum frequency scheme of super luminescent light frequency doubled light and narrowband light in

关 键 词：非线性光学 超辐射光 非线性频率转换 群速度失配 

分 类 号：O437[机械工程—光学工程]