Spatial characteristics of emission from electron oscillation driven by femtosecond laser pulses

The characteristics of spatial distribution of emission from electron oscillation are analyzed with a single electron model under femtosecond laser pulses of different intensity and polarizations. It shows that with the increase of laser intensity, for circularly polarized laser pulses, the angular distribution is tipped forward more and more and increase in magnitudes; for linearly polarized laser pulses, the radiation pattern is changed from the fourfold rotational symmetry bifoliate pattern same as that from a dipole antenna to twofold rotational symmetry trefoil pattern.