Nonlinear Surface Polaritons near the Interface between a Magneto-Optical Substance and a Nonlinear Metamaterial with a Permittivity Close to Zero

Abstract

Relevance. Considerable attention of researchers is drawn to nonlinear surface optical waves, as they are promising for application in optical information processing systems, ultra-sensitive sensors, and modern telecommunications components. Purpose. To obtain an exact solution of the Maxwell equation system for TM-polarised nonlinear surface polaritons propagating along the interface between an optically linear magnetic medium and an optically nonlinear medium with saturated nonlinearity. Methods. Analysis of the properties of nonlinear surface polaritons (NSP) and mathematical modelling of the dependence of the permittivity of a nonlinear medium on the intensity are used. Results. TM-polarised nanoparticles propagating along the interface of a magneto-optical medium and a nonlinear optical metamaterial with a permittivity close to zero (ENZ-metamaterial) are studied. For NSP in such a structure, an exact solution of the Maxwell equation system is obtained, considering the saturation effect of optical nonlinearity. On this basis, the dependences of constant propagation on the total energy flux of NSP and energy fluxes in contact media in the structure were investigated: magneto-optical ENZ-metamaterial with negative permittivity/nonlinear self-focusing ENZ-metamaterial. Conclusions. The NSP energy flow is positive in a nonlinear medium and negative in a linear one. As the saturation level decreases, the NSP energy fluxes in the contacting media increase modulo, if the value of the NSP propagation constant (NSPPC) is fixed. The lowest NSPPC value for guiding nonlinearity is obtained when the total energy flow of the NSP becomes zero. As the saturation level decreases, the NSP propagation variable (NSPPV) increases. At a fixed NSPPC, with a decrease in the magnetic permeability, the energy fluxes of NSP in the contacting media increase. When the magnetic permeability decreases to zero and the NSP energy flux is positive, the NSPPV change range narrows