Suppression of non-dipole effects in strong-field ionization

In this paper, we propose a simple and experimentally feasible method to suppress non-dipole effects in strong-field ionization by introducing a weak bichromatic control field polarized along the laser-field propagation direction. Within the framework of the non-dipole strong-field approximation, we derive the form of this control field and demonstrate that it compensates the leading magnetic-field-induced drift in the photoelectron momentum distribution. Numerical simulations for helium atom show that the control field restores the dipole-like photoelectron spectrum and electron trajectories for both direct and rescattered electrons. While residual non-dipole contributions remain in the ionization matrix element and rescattering action, their influence on the observables is minor. The proposed approach provides a transparent means of isolating and controlling non-dipole effects and offers new opportunities for exploring their role in complex field configurations as well as in strong-field electron dynamics.