Peculiarities of localization of excitations near the interlayer between nonlinear focusing media under conditions of nonlinear interactions with layer interfaces

Localized states exist in a three-layer structure comprised of the two nonlinear crystals with positive nonlinearity, between which a linear plate with a finite thickness is clamped, whereas the layer interfaces are characterized by a nonlinear response. The frequencies of such localized states that exist only at different values of the intensity of interaction of the layer interfaces with excitations are obtained. The conditions for the existence of such states are figured out and estimates of the characteristic scale of field localization are given.