OPTICAL-PROPERTIES OF MULTILAYER STRUCTURES .4. NONLINEAR ABSORPTION OF LIGHT IN MULTILAYER STRUCTURES

The theory of non-linear response of an electronic subsystem in planar multi-layer structures (including quantum wells) to a strong electrom agnetic field is developed. On the basis of the exact Hamiltonian of t he electron-phonon interaction for such structures a non-linear dielec tric permittivity tensor is obtained by the statistical operator metho d in the path integration representation. In the three-layer structure s with a thin middle semiconducting layer and moderate values of the d ielectric permittivity of the outer dielectric media the contribution to the absorption due to the interaction of electrons with surface pho nons is found to prevail over that of bulk phonons and to ensure a sub stantially more rapid rise in the absorption coefficient with increasi ng intensity in comparison with the case of a semiconductor crystal.