Description of optical echo without the given-field approximation
Khadzhi P. I.
The occurrence of optical-echo phenomena in two-level media is analyzed without the approximation of a given field. The polarization of the medium and the intensity of the echo signal depend in a complex way on both the areas under the pulses and on the area under the "material" field and the relation between (on the one hand) the photon densities of each pulse and (on the other) the density of two-level atoms (excitons) of the medium.