空间非均匀激光场驱动的原子非次序双电离

Nonsequential double ionization of atoms driven by spatially inhomogeneous laser fields

利用三维经典系综模型,研究空间非均匀激光场驱动的氙原子非次序双电离,并对比了空间均匀激光场的情况.结果显示,波长较短时,空间非均匀激光场与空间均匀激光场的非次序双电离的产率较为相近.随着波长的增大,较高激光强度时空间非均匀激光场下非次序双电离受到越来越明显的抑制.相比于空间均匀激光场,空间非均匀激光场下非次序双电离两电子的末态发射角表现出更强烈的关联特性,特别在较大的激光波长下,两电子的末态发射角几乎全部集中在0°附近,这意味着两电子往往是平行发射到相同方向.此外,波长由近红外增大到中红外时,空间非均匀激光场下非次序双电离的有效再碰撞均由第1个电子的第1次返回主导,而空间均匀激光场下则呈现由第1次返回主导到第2次返回主导的转变.进一步,通过反演分析非次序双电离的经典轨迹,揭示了空间非均匀激光场下关联电子超快动力学过程的更多细节.

Using a three-dimensional classical ensemble method,we investigate the nonsequential double ionization(NSDI)of xenon atoms from the near infrared wavelength to the mid-infrared wavelength in spatially inhomogeneous laser fields,and compare the results with those from spatially homogeneous laser fields.The results show that the NSDI probability curves from spatially inhomogeneous laser field and spatially homogeneous laser field at short wavelength are similar to each other.With the laser wavelength increasing,NSDI at the high intensities is more and more suppressed for spatially inhomogeneous laser field.0°Compared with the result from the spatially homogeneous laser field,the final emission angle of two electrons from the NSDI exhibits a very strongly correlated characteristic in the spatially inhomogeneous field,especially at a longer laser wavelength,the final emission angles of two electrons are almost both concentrated around,meaning that the two electrons are always emitted into the same direction parallelly.Moreover,effective recollision of the NSDI is always dominated by first return of the first electron from the near infrared to the mid-infrared inhomogeneous laser fields,however,the transition from the first return dominance to the second return dominance occurs in the spatially homogeneous laser fields.Further,we reveal the more details of the ultrafast dynamics of the correlated electrons in the spatially inhomogeneous laser field by back-tracing the classical trajectories of NSDI.