Simulation of surface plasmon propagation in planar waveguides

Surface plasmon propagation in a multilayer planar waveguide structure was studied. We are proposing an algorithm for solving the characteristic equation in order to determine the complex effective refractive index neff. The absolute minimum of the complex characteristic equation is determined in three steps considering the nodes of an increasingly refined mesh. After each step a new mesh is created around the node of the previous mesh in which the minimum was found. Tests on a 4-layer structure proved that the algorithm is convergent, rapid and accurate.