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 excit ation energy on the other side of the interface. We demonstrate that t he Fermi resonance interaction across each interface gives rise in the classical limit to nonlinear plane waves propagating through the supe rlattice. A general form of the dispersion law has been found. The pec uliarities of this dispersion law are discussed in several particular cases.