Two-photon double ionization of H2 in intense femtosecond laser pulses

Triple-differential cross sections for two-photon double ionization of molecular hydrogen are presented for a central photon energy of 30 eV. The calculations are based on a fully ab initio, nonperturbative approach to the time-dependent Schrodinger equation in prolate spheroidal coordinates, discretized by a finite-element discrete-variable representation. The wave function is propagated in time for a few femtoseconds using the short, iterative Lanczos method to study the correlated response of the two photoelectrons to short, intense laser radiation. The current results often lie in between those of Colgan et al. [J. Phys. B 41, 121002 (2008)] and Morales et al. [J. Phys. B 42, 134013 (2009)]. However, we argue that these individual predictions should not be compared directly with each other, but preferably with experimental data generated under well-defined conditions.