强电场和磁场中H^—的光剥离截面——半经典闭合轨道理论

应用Du和Delos等人的半经典闭合轨道理论,将研究范围由二维空间推广到三维。通过这一理论推导出了当电场和磁场成任意夹角时H^-的光剥离截面的计算公式,并且计算了几种不同夹角的光剥离截面,结果表明出很大的振荡特性。     

Photodetachment of negative hydrogen ion in circularly polarized monochromatic and bichromatic laser fields

We theoretically have investigated the detachment of negative hydrogen ion in circularly polarized monochromatic and bichromatic laser fields by calculating the photoelectron momentum distributions (PMDs). We find that the PMDs are controlled by the electric field of laser pulse. For circularly polarized monochromatic laser fields, the PMDs are perfect and isotropic rings, and the photodetachment rates in random direction are same. For this case, the photoelectron momentum spectra directly reflect the electronic distributions of negative hydrogen ion. For circularly polarized bichromatic laser field, the PMDs are inversion asymmetric, but symmetric about a certain axis. The emission directions of the photoelectrons vary with the electric field shape, that is to say that the emission directions of the photoelectrons vary with the carrier-envelope (CE) phases, which decide the electric field of laser pulse. The maximal photodetachment rates and the spectra shape, however, are same for the different CE phases.     

超快强激光场中离子的光离解：光电离标度规律的一个验证

在量子电动力学框架下,采用全量子非微扰散射理论,研究了超快强激光场中离子的光离解。发现在保持周期数与载波-包络相位不变时,对相同的阈上离解峰,当用频率为 γ倍,强度为γ ³倍的激光激发结合能为γ倍的离子时,光电子的角分布不变,  γ为任意正实数。这一研究验证了周期量级超短激光脉冲中光电离的标度规律。