Effect of two-cutoff structure in laser-induced recollision dynamics

We theoretically identify a two-cutoff structure in the recollision energy distribution of the third-return recollision trajectories whose contribution is dominant in the high-energy part of the above-threshold ionization (ATI) spectrum. The additional second cutoff in the recollision energy distribution, resulted from the acceleration of Coulomb field to specific recollision trajectories, induces an extension of the Two-dimensional (2D) photoelectron momentum spectrum and will affect the differential cross-sections (DCS) extracted in laser-induced electron diffraction (LIED) scheme. Both the position and relative yield of the second cutoff decrease with increasing laser intensity. Therefore, the effect of the second cutoff should be taken into account when the laser intensity is not so high.