NONLINEAR-OPTICAL VIBRATIONS IN ORGANIC SUPERLATTICES WITH INTERFACE FERMI RESONANCE

We discuss the nonlinear dynamics of organic superlattices in the case of interface Fermi resonance, which occurs when the energy h omega(c) of excitation on one side of each interface is approximately equal to 2 ($) over bar h omega(b), where ($) over bar h omega(b) is the excitation energy on the other side of the interface. We demonstrate that the Fermi resonance interaction across each interface gives rise in the classical limit to nonlinear plane waves propagating through the superlattice. A general form of the dispersion law has been found. The peculiarities of this dispersion law are discussed in several particular cases.