  We study the influence of laser radiation on the electron transport through a
molecular wire weakly coupled to two leads. In the absence of a generalized
parity symmetry, the molecule rectifies the laser induced current, resulting in
directed electron transport without any applied voltage. We consider two
generic ways of dynamical symmetry breaking: mixing of different harmonics of
the laser field and molecules consisting of asymmetric groups. For the
evaluation of the nonlinear current, a numerically efficient formalism is
derived which is based upon the Floquet solutions of the driven molecule. This
permits a treatment in the non-adiabatic regime and beyond linear response.
