基于强激光与等离子体波导激发高亮度、圆偏振高次谐波理论研究

Theoretical Investigation of High-Brightness and Circularly Polarized HighOrder Harmonics Excited by Intense Laser and Plasma Waveguide

利用强激光与等离子体相互作用产生的频谱特性可调谐的高次谐波辐射(HHG)一直是国内外研究的热点。利用二维粒子模拟程序对超强超短激光脉冲驱动等离子体波导激发的高次谐波的辐射特性与相关电子动力学行为进行了研究,讨论了驱动激光强度、等离子体密度等关键参数对所产生谐波的转换效率与椭偏率的影响与调控规律,并根据Baeve Gordienko Pukhov(BGP)理论分析了其内在物理机制。该研究为开发高亮度、超短超快、圆偏振、深紫外及软X射线波段台面型辐射源提供了新的技术途径,进而有望在超高灵敏度、超快速的物质手性检测手段的研发方面起到积极促进作用。

High harmonic generation(HHG)with tunable spectral characteristics by intense laserplasma interaction has long been a research hotspot both in China and abroad.In this study,a twodimensional particle simulation program is employed to investigate the radiation characteristics of the HHG by the plasma waveguide driven by an ultrashort ultraintense laser pulse and the related dynamic behavior of the electrons.The influences and regulation laws of key parameters,including driving laser intensity and plasma density,on the conversion efficiency and ellipticity of the HHG are discussed,and their underlying physical mechanisms are analyzed by the BaeveGordienkoPukhov(BGP)theory.This study provides a novel technical route for developing highbrightness,ultrashort ultrafast,and circularly polarized mesatype radiation sources in the wavelength range from deep ultraviolet to soft Xray and is thus expected to further facilitate the development of ultrafast ultrahighsensitivity techniques for chirality detection.