Dispersion characteristics of surface plasmon polariton modes in a metallic slab waveguide with nonlinear magnetic cladding

We investigate the propagation characteristics of surface plasmon polaritons along a slab waveguide with a nonlinear magnetic cladding characterized by permeability mu = mu(l) + mu H-nl(2) and a linear substrate. The dispersion relation for the surface plasmon polariton modes supported by the structure was derived and numerically solved. The dependance of mode behavior on input power was studied. As the input power increases, the propagation constant of the modes increases. The effect of self focussed peak on the mode confinement near the interface and the resulting propagation characteristics of the plasmon modes were investigated. Increase in metal film thickness lifts the degeneracy of nonlinear plasmon modes supported by the waveguide. It has been observed that the propagation length is not a single valued function of input power which is crucial in understanding optical nano-switches. (C) 2013 AIP Publishing LLC.