Above-threshold ionization of hydrogen atom in chirped laser fields Project supported by the National Natural Science Foundation of China (Grant Nos. 11664035, 11465016, 11764038, 11364038, and 11564033). |
(color online) Low-energy photoelectron 2D momentum distributions of H in the multiphoton ionization region by the chirped pulse with three different chirp rates: (a) ξ = −1.73, (b) ξ = 0, and (c) ξ = 1.73. The laser parameters are the same as those in Fig. |