Influence of initial phase on electron motion and spatial emission characteristics from electron driven by tightly focused linearly polarized laser pulse

Based on the knowledge of electrodynamics and the nonlinear Thomson scattering framework, a single-electron motion and radiation model is established and numerical simulation is carried out to study the effect of the initial phase on the electron motion and radiation characteristics under a tightly focused linearly polarized laser pulse. It is demonstrated that when the initial phase of the tightly focused laser pulse varies within 0–π and 2π–π, respectively, the electron motion spectrum and radiation power distribution break the symmetric distribution mode. On this basis, the motion state and radiation distribution of single electron change with the initial phase are described in detail. Further analysis shows that the extreme point where the peak value and peak power angle of the upper and lower parts of the stimulated electron radiated power distribution vary with the initial phase both appears at Δ = 150° when the initial phase changes from 0 to π, and appears around when it changes from 2π to π. The change curves of both show a special antisymmetry phase phenomenon under tight focus. This discovery offers a theoretical and numerical foundation for the investigation of high-energy electron radiation from multiple perspectives and aids in the precise measurement of ultra-intense laser characteristics in practical applications. (author)