Near-field effect in an ultrathin nonlinear film of resonant atoms

In nonlinear resonance optics, the boundary-value problem of the interaction of steady quasiresonant optical radiation with an ultrathin film is solved within the framework of a model of a discretely continuous film of atoms in which the point of observation is surrounded by discretely distributed atoms forming a truncated Lorentz sphere. Outside the sphere the distribution of atoms is continuous. A closed system, formed by an integral field equation and modified Bloch equations, is used to calculate the microscopic field inside the film and thus the dynamic detuning from a resonance, which takes account of the near-field effect, i.e. of the discretely continuous distribution of atoms in the film. A significant dependence of the effect on the nature of the symmetry of the distribution of atoms in the film is demonstrated.