In the nonperturbative intensity regime exact solutions of the
time-dependent Schrödinger equation of a few-body system interacting
with an ultrashort intense laser pulse
can be obtained by direct numerical integration. Such simulations
distinguish themselves just in the respective Hamiltonian of the Schrödinger
equation. This
is the basis of our program package, which provides an unified basis
for a number of strong-field problems. It consists of routines
for the propagation of the wavefunction on the grid and the
post-processing of the data. The result is a virtual
lab for the analysis and visualization of few-body processes
on an attosecond time scale. Applications for
single-active-electron as well as correlated electron
dynamics have been realized.
The IMST provides a systematic ab-initio approach to
investigate the dynamics of atoms and molecules interacting with
intense laser radiation. Structurally, the usual S-matrix
expansions, as the time-dependent perturbation theory, are based
on a single partition of the total Hamiltonian of the system into
an unperturbed reference Hamiltonian and the interaction potential.
Such an 'one-potential' scheme is not very useful for the analysis
of strong-field processes, in which the internal Coulomb interaction
between the charged particles in the atom or molecule and the
external laser-electron interaction energy are of comparable strength.
Thus, one requires to be able to account simultaneously of
different reference Hamiltonians in the initial, intermediate and
final states. The IMST is such a more general S-matrix
expansion scheme. It provides an effective method for analyses of
direct and rearrangement processes that can occur in the presence
of intense laser fields.