  In the context of nonlinear scattering, a continuous wave incident onto a
nonlinear discrete molecular chain of coupled oscillators can be partially
absorbed as a result of a 3-wave resonant interaction that couples two HF-waves
of frequencies close to the edge of the Brillouin zone. Hence both nonlinearity
and discreteness are necessary for generating this new absorption process which
manisfests itself by soliton generation in the medium. As a paradigm of this
nonlinear absorption we consider here the Davydov model that describes
exciton-phonon coupling in hydrogen bonded molecular chains.
