Initial Phase-Sensitivity Of Spatial Characteristics In The Tightly And Non-Tightly Focused Linearly Polarized Few-Cycle Region

Within the frame of electrodynamic and nonlinearly Thomson scattering, we study the initial phase-sensitivity with respect to spatial characteristics of a static electron irradiated by Guassian linearly polarized few-cycle laser pulse for different beam waists. With the combination and comparison of the electron's real-time motion and radiation conditions, the initial phase-sensitivity turns out with inverse proportional relation to the beam waist where the radiation's transverse shift of varied initial phases is irregular in the non-tightly focused case. Furthermore, by changing the initial phases, the petal-like full spatial radiation pattern changes from 4 unstable pieces to 2 constant pieces and the radiated energy shift slows down with the beam waist evolving from b(0) = 1 to b(0) = 10. Finally, with initial phase phi increasing from 0 to pi we discover an interesting phenomenon for the first time, where the normalized maximal radiated power and corresponding azimuth angle fluctuate in the form of ripples and ladders in tightly-focused case b(0) = 1, in contrast to the perfectly symmetry with respect to b(0) = 0.5 pi for the maximal radiated power in non-tightly focused case b(0) = 10.