优化有效势模型与拟谱法在碱金属高次谐波研究中的应用

摘要/Abstract

摘要： 将参数优化有效势模型与拟谱-分裂算符方法相结合，研究了强激光场下碱金属原子气的高次谐波产生过程。结合参数优化有效势特点对演化矩阵进行了处理，保证了演化过程中含时波函数与闭壳层轨道的正交性。选取波长为3038nm、强度约为1013W/cm2的中红外激光场作为驱动场，计算了锂、钠、钾原子的高次谐波谱。研究了长激光脉宽下里德伯态钠原子束缚态跃迁峰对谐波产生的贡献。结果表明，里德伯态与基态的共振会使低阶谐波的强度增加一个量级。验证了该方法在描述含时演化过程中电子重俘获过程的可靠性。

关键词: 非线性光学, 高次谐波, 有效势, 碱金属, 中红外激光, 里德伯原子, nonlinear optics, high harmonics, effective potential, alkaline atom, mid-infrared laser, Rydberg atom

Abstract: By combining numerical-parameterized optimized effective potential (NPOEP) method and the pseudospectral time-evolution method, the high-harmonics generation (HHG) of alkaline atoms driven by linearly-polarized intense laser fields are investigated. The evolutional matrix is modified according to the features of the NPOEP model, to guarantee that the wave-function of the system is kept being orthogonal to the closed-shell eigenvectors. A mid-infrared laser pulse of 3038nm of wavelength and 1013Wcm-2 of intensity is chosen to be the driven field to investigate the contribution of the Rydberg atoms in HHG process. The results prove that the existing Rydberg state will enhance the power of HHG of specific order more than an order. The reliability of this method in the recombining process of HHG is also proved.

中图分类号:

0437

张硕乔豪学. 优化有效势模型与拟谱法在碱金属高次谐波研究中的应用[J]. J4, 2017, 34(2): 212-219.

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