P-polarized nonlinear surface polaritons near the surface of an epsilon-near-zero metamaterial with saturable permittivity: Threshold cases

Abstract

We study p-polarized nonlinear surface polaritons (NLSP) propagating along the interface of an epsilon-near-zero (ENZ) metamaterial with saturable nonlinearity and an optically linear ENZ medium. On the base of the exact solution of Maxwell's equations we investigate the relationship between the NLSP propagation constant and the NLSP energy flux for the systems where surface polaritons can not exist in linear approximation but can exist in nonlinear case. We show that the relationship depends considerably from the saturation level of metamaterial permittivity. The propagation constant variation is limited for the self-focusing and is unlimited for the self-defocusing case. In the both cases effect of saturation of nonlinear permittivity leads to higher values of the NLSP energy flux compared to the energy flux calculated in the frameworks of Kerr model.