Nonlinear Surface Waves in a Symmetric Three-Layer Structure That Is Composed of Optical Media with Different Formation Mechanisms of Nonlinear Response

Abstract

We consider the propagation of surface TM waves in a three-layer structure the inner layer of which is formed by a plate of a crystal with a Kerr type focusing nonlinearity, while its outer layers are uniaxial photorefractive crystals with the diffusion nonlinearity formation mechanisms. Nonlinear surface waves that differ in the character of their decay can propagate along the interfaces between the layers. The amplitudes of waves of one type decrease without oscillations with increasing distance from the interface as the waves propagate into the depth of the outer layers of the photorefractive crystals, while the amplitudes of waves of the other type decrease with oscillations. The wave profiles can be either symmetric or antisymmetric with respect to the center of the three-layer structure. The waves with the symmetric profile distribution, the amplitudes of which decrease into the depth of the photorefractive crystals either with or without oscillations, can be of two types, while those with the antisymmetric distribution can be only of one type. For the long-wavelength propagation regime of surface waves, explicit analytical dependences of the propagation constant on the characteristics of the layered structure are found and the conditions for their existence are determined.