  We consider the propagation of extremely short pulses through a dielectric
thin film containing resonant atoms (two level atoms) with permanent dipole.
Assuming that the film width is less than the field wave length, we can solve
the wave equation and reduce the problem to a system of generalized Bloch
equations describing the resonant atoms. We compute the stationary solutions
for a constant irradiation of the film. Superimposing a small amplitude linear
wave we compute the reflection and transmission coefficients. From these, one
can then deduce the different parameters of the model. We believe this
technique could be used in experiments to obtain the medium atomic and
relaxation parameters.
