Circularly polarized molecular high-order harmonic generation in H2+ with intense laser pulses and static fields
Circularly polarized molecular high-order harmonic generation in H2+ with intense laser pulses and static fields
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DOI：
10.1103/physreva.83.063422
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发表时间：
2011-06-30
影响因子：
2.9
通讯作者：
Bandrauk, Andre D.
中科院分区：
文献类型：
--
作者：
Yuan, Kai-Jun;Bandrauk, Andre D.
从H-2（+）分子离子的适当时相关薛定谔方程（TDSE）出发，研究了强圆极化激光脉冲和静电场联合作用下分子高次谐波的产生。结果表明，在给定的静场强下，圆极化激光脉冲的最大能量为I-p + 9.05U(p)，其中I-p为电离势，U-p = e -0(2)/4m(e) ω(2)(0)为幅值为e -0、频率为ω(0)时的有源能量。静态场控制着电子与母离子的再聚，并由平衡态H-2(+) TDSE的数值解证实。为了产生圆极化MHOHG光谱，发现椭圆极化脉冲和静电场的组合是最有效的。通过Gabor变换获得的时频分析被用来识别产生这些高次谐波的电子回收时间。发现只有单一的再回忆轨迹才会产生圆极化谐波，从而产生高频圆极化阿秒脉冲的新源。
Molecular high-order harmonic generation (MHOHG) by a combined intense circularly polarized laser pulse and static electric field has been studied from the appropriate time-dependent Schrodinger equation (TDSE) for the H-2(+) molecular ion. It is found that for a particular static field strength derived from a classical model, efficient MHOHG spectra are obtained with maximum energy I-p + 9.05U(p), where I-p is the ionization potential and U-p = E-0(2)/4m(e)omega(2)(0) is the ponderomotive energy at amplitude E-0 and frequency omega(0) of the circularly polarized laser pulse. The static field controls recollision of the electron with parent ions and is confirmed by numerical solutions of the H-2(+) TDSE at equilibrium. To produce circularly polarized MHOHG spectra, a combination of an elliptically polarized pulse and a static electric field is found to be most efficient. A time-frequency analysis obtained via Gabor transforms is employed to identify electron recollision times responsible for the generation of these high-order harmonics. It is found that only single recollision trajectories contribute to the circularly polarized harmonics, thus generating new sources for high-frequency circularly polarized attosecond pulses.