Double ionization of helium in an elliptically polarized laser field

In this letter we discuss the double ionization of helium in intense, elliptically polarized laser fields. We extend a model previously used for linear polarizations to the case of a two-dimensional model atom subject to a laser field of arbitrary ellipticity. Our results show a decrease in the efficiency of the non-sequential double ionization as the ellipticity of the driving field is increased, consistent with the recollision picture of double ionization. Our results are in qualitative agreement with previous experimental measurements.