Full spatial characteristics of emission from electron oscillation driven by linearly polarized laser pulses

Driven by the electromagnetic field produced by linearly polarized femtosecond laser pulse, the electron's relativistic oscillation and the corresponding full spatial radiation have been studied theoretically and numerically. The new finding is electron's radiated power per solid angle by laser pulse with low intensities is almost the same as that produced by a dipole antenna (four-fold rotational symmetry), whereas for the radiation generated by high laser intensities, the radiation takes on two-fold rotational symmetry pattern with further increase of laser intensity. Therefore, this method is of great use in determining the intensity of linearly polarized laser pulses indirectly in real experiment.