Abstract. We consider a time-dependent Hamiltonian H(t) = 1 2, where the external electric field E(t) and the short-range electric potential V (t, x) are time-periodic with the same period. It is well-known that the short-range notion depends on the mean value E 0 of the external electric field. When E 0 = 0, we show that the high energy limit of the scattering operators determines uniquely V (t, x). When E 0 = 0, the same result holds in dimension n ≥ 3 for generic short-range potentials. In dimension n = 2, one has to assume a stronger decay on the electric potential.