Intense field ionization of molecules with ultra-short laser pulses - enhanced ionization and barrier-suppression effects

Abstract

Exact numerical solutions of the time-dependent Schrödinger equation have been performed in order to calculate ionization rates in intense short laser pulses for linear three-dimensional and linear one-dimensional . All molecular ions exhibit unusually large ionization rates at large critical interfragment distances . Expressions are derived for based on quasistatic models of field-induced suppression of electron Coulomb barriers in the molecules. The predicted agree satisfactorily with the exact numerical results. In the symmetric case, laser-induced electron localization can also enhance ionization. The present numerical results show that large or enhanced ionization rates exceeding those of nonionized fragments will dominate for laser pulses which are sufficiently long to allow dissociative ionization fragments to reach such critical distances.