Optically nonlinear s-polarized waves in dielectric superlattices

We study theoretically the s-polarized electromagnetic waves in two-component superlattices, in which one component has a Kerr-type nonlinear dielectric constant. Numerical results are obtained for the effective refractive index (and hence the dispersion relation) of these modes as a function of an effective nonlinear coefficient and the geometric parameters of the structure. Attention is focused on determining both edges of the nonlinear wave subbands, which are shown to form a rich spectrum in these periodic structures. A more than double-valued relation between the effective refractive index and the electric field intensity is obtained in some cases, contrasting with the situation in structures having a single nonlinear layer. This property offers a potential application to non resonant multi stable devices