摘要
椭偏阿秒脉冲作为融合超短时间尺度(阿秒)与椭圆偏振特性的光场,在探究物质超快手性动力学过程及X射线磁圆二色性等前沿方向具有重要应用价值.本研究基于含时薛定谔方程的数值求解,通过设计非均匀线偏振驱动激光场与Ne相互作用,系统地研究了驱动激光场的非均匀度以及初始轨道的轨道角动量对孤立椭偏阿秒脉冲产生的调控规律.本文计算了不同非均匀度的驱动激光场作用下的氖原子的高次谐波谱,结果表明非均匀度参数的调节显著影响了高次谐波谱平滑程度以及频谱展宽程度,进一步影响了辐射的阿秒脉冲的性质.此外,研究结果表明初始轨道的轨道角动量特性对脉冲偏振态起决定性作用,当初始轨道角动量为零(如1s轨道)时,辐射的阿秒脉冲是线偏振,而当初始轨道角动量不为零(如环流态2p_-轨道)时,辐射的脉冲则为椭圆偏振.该研究结果为非均匀线偏激光场驱动下原子孤立椭偏阿秒脉冲的实现及偏振特性调控提供了理论依据.
Elliptically polarized attosecond pulse has significant applications in studying the ultrafast chiral dynamics and X-ray magnetic circular dichroism(XMCD)due to its ultrashort time-scale(attosecond)and elliptical polarization characteristics.In this work,the interaction between the non-uniform linearly polarized laser field and the Ne atoms is simulated by numerically solving the time-dependent Schrödinger equation.Specifically,the influences of the non-uniformity of the driving field and the orbital angular momentum(OAM)of the initial orbital on high-order harmonics(HHs)and attosecond pulses are revealed.HHs generated by the linearly polarized laser fields with different non-uniformities are calculated.The results indicate that the non-uniformity significantly influences the smoothness and spectral broadening of the harmonic spectra,consequently affecting the properties of the attosecond pulses.Moreover,our findings also reveal that the OAM of the initial orbital plays a significant role in the polarization state of the attosecond pulses.When the OAM is zero(e.g.,1s orbital),the radiated attosecond pulses are linearly polarized,whereas non-zero OAM(e.g.,current carrying state 2p-orbital)leads to elliptically polarized emission.This study provides a theoretical foundation for generating and controlling elliptically polarized isolated attosecond pulses by using non-uniform linearly polarized laser fields,and offers new possibilities for ultrafast spectroscopy and magnetic material characterization.
作者
涂乔舒
张晓凡
占诗羽
秦梅艳
柯少林
廖青
TU Qiaoshu;ZHANG Xiaofan;ZHAN Shiyu;QIN Meiyan;KE Shaolin;LIAO Qing(Hubei Key Laboratory of Optical Information and Pattern Recognition,Wuhan Institute of Technology,Wuhan 430200,China)
出处
《物理学报》
北大核心
2025年第19期153-163,共11页
Acta Physica Sinica
基金
国家自然科学基金(批准号:11904269,12174295)
湖北省自然科学基金(批准号:2021CFB300)资助的课题。
关键词
高次谐波
椭偏孤立阿秒脉冲
环流态
非均匀场
high order harmonic
elliptically polarized isolated attosecond pulse
current carrying state
nonunifom laser field
