Above-threshold ionization of hydrogen atom in chirped laser fields<xref rid="cpb_27_7_073203fn1" ref-type="fn">*</xref> <fn id="cpb_27_7_073203fn1"> <label>*</label> <p>Project supported by the National Natural Science Foundation of China (Grant Nos. 11664035, 11465016, 11764038, 11364038, and 11564033).</p> </fn>

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).

Ni Yuan-Yuan¹, Zhao Song-Feng^{1, †}, Li Xiao-Yong², Wang Guo-Li¹, Zhou Xiao-Xin¹

(color online) Low-energy photoelectron 2D momentum distributions from single-photon ionization by the laser pulses for three different chirp rates: (a) ξ = −1.73, (b) ξ = 0, and (c) ξ = 1.73. To make both ATI peaks (i.e., S = 1 and 2) visible, we renormalize the S = 2 with another normalization factor. The laser parameters are the same as those in Fig. 5.