Dependence of nonsequential double ionization of He on intensity ratio of orthogonal two-color field
氦原子非次序双电离对正交双色场强度比的依赖关系

Using classical ensemble model,the dependence of nonsequential double ionization of He on intensity ratio of orthogonal two-color field is investigated.It is shown that this dependence is related to the relative phase(φ) of two-color pulse.Whenφ= 0.25π,with intensity ratio increasing,correlated momentum distribution along the polarization of long wavelength field changes from correlation to anticorrelation pattern;whenφ= 0.35π,0.45π,correlated momenta are mainly distributed in the first and third quadrants,correlation pattern is nearly unchanged with the variation of intensity ratio.Back analyses of recollision time,recollision angle,recollision momentum of double ionization trajectories are responsible for the above results,and reveal the control of recollision time and the recollision angle in NSDI by orthogonally polarized two-color field.