Fig. 1. Vector potential of linearly polarized laser with different polarization directions. (a) Θ=0; (b) Θ=π/6

Fig. 2. PMD as a function of angle Θ between 2p_z state of hydrogen atom and laser polarization direction for (a) Θ=0; (b) Θ=π/6; (c) Θ=π/3; (d) Θ=π/2

Fig. 3. Atomic orbitals of hydrogen in momentum space and cross-sections at different longitudinal momenta. (a), (b) 1s orbital and 2pz orbital; (c), (d) cross-sections at different longitudinal momenta for 1s orbital and 2pz orbital

Fig. 4. Photoelectron yield and asymmetry parameter as a function of angle Θ. (a) PMD and corresponding left and right regions at Θ=π/6; (b) photoelectron yields of left and right regions as a function of angle Θ; (c) asymmetry parameters of PMD and 2pz state as a function of angle Θ

Fig. 5. Dependence of asymmetry parameter on Keldysh parameter. (a) Asymmetry parameter as a function of angle Θ for different Keldysh parameters; (b) asymmetry parameter as a function of Keldysh parameter γ at Θ=π/4

Fig. 6. Pump-probe laser pulse induced PMD of hydrogen atom and analysis of factors influencing asymmetry parameter at Θ=π/3. (a) Electric fields of pump and probe pulses; (b) PMD of hydrogen atom at 1s state ionized by pump-probe laser pulse; (c) asymmetry parameter, normalization of photoelectron yield, and population of 2pz state at end of pump pulse as a function of pump pulse duration; (d) asymmetry parameter as a function of time delay between pump pulse and probe pulse at peak positions