Fabry-Perot bistability with nonlinear absorption and dispersion

Calculations of light interaction with medium exhibiting both nonlinear absorption and dispersion based on one plane-wave and slowly varying envelope approximations are presented. A two level model of atoms (molecules) has been assumed as a basis for the nonlinear susceptibility which was then determined without expanding it in a series of the electric field. General formulae for the intensity of the transmitted wave are derived and some numerical calculations are performed. It has been shown that under this model the optical bistability is possible and some conditions for its onset have been established.