Parabolic approximation analytical model of super-resolution spot generation using nonlinear thin films: Theory and simulation

In this work, we present a theoretical analytical model called the parabolic approximation analytical model that considers the absorption coefficient and refractive index in a parabolic approximation profile along the radial direction. By using this model the generation of a super-resolution spot is analyzed in detail, and a numerical simulation subsequently conducted to verify the analytical model. This work is helpful in understanding the super-resolution effect of nonlinear thin films.