Abstract

After passing through a nonlinear medium, a laser beam propagates in free space and transmits through an aperture in a screen; this simple device has power limiting action.¹ We carried out a numerical analysis of the refraction of a laser beam by a bounded nonlinear medium and of the diffraction during the beam's subsequent free-space propagation using a 2-D Gaussian input profile. With a slowly varying envelope approximation, the Maxwell wave equation was solved using the definite difference method. Thus no thin-medium approximation is needed. Steady-state transverse profiles in the near and far fields have been calculated. We found that the results are in good qualitative agreement with those of other experiments.²

© 1987 Optical Society of America