Effects of elliptical polarization on strong-field short-pulse double ionization.

We predict new end-of-pulse behavior in high-field atomic double ionization. Calculations of atomic electron trajectories in short intense laser pulses confirm our analysis of elliptical polarization. We exhibit a four-band structure in ion momentum distributions under various ellipticities, and predict that sequential and nonsequential double ionization can be cleanly distinguished under elliptical polarization.