Pulse length effects in long wavelength driven non-sequential double ionization

Abstract

We present a joint experimental and theoretical study of non-sequential double ionization (NSDI) in argon driven by a 3100-nm laser source. The correlated photoelectron momentum distribution (PMD) shows a strong dependence on the pulse duration, and the evolution of the PMD can be explained by an envelope-induced intensity effect. Determined by the time difference between tunneling and rescattering, the laser vector potential at the ionization time of the bound electron will be influenced by the pulse duration, leading to different drift momenta. Such a mechanism is extracted through a classical trajectory Monte Carlo-based model and it can be further confirmed by quantum mechanical simulations. This work sheds light on the importance of the pulse duration in NSDI and improves our understanding of the strong field tunnel-recollision dynamics under mid-IR laser fields.

The modeling non-sequential double ionization of helium atom under high-intensity femtosecond laser pulses with shielding charge approximation

“…This mechanism is called re-collision induced excitation with subsequent ionization (RESI) [12]. Although an alternative theory is known as the shake-off theory [11,13,14]. The shake-off theory attributes the detachment of the second electron from the nucleus to the matching of the electron wave function with abrupt changes that result from the separation of the first electron [15].…”