Modelling of one-dimensional magnetoplasmonic periodic structures by the effective refractive index method

An external DC magnetic field may change the dispersion diagram of periodic structures, so that tunable reciprocal and non-reciprocal plamonic components may be constructed. In this study, the effect of an external DC magnetic field on the dispersion diagram of plasmonic periodic structures will be investigated by the effective refractive index method. Investigations are focused on the Voigt and Faraday configurations, although it can be extended to other configurations. In this regard, the wave equation for both structures is solved, eigenpropagation constants and eigenpolarisation are derived. Then, the effective propagation constant and finally, the dispersion diagram for the Voigt and Faraday structures will be derived. The effect of the bias field is investigated on the aforementioned structures. It is seen that tunable periodic structures can be achieved by the magnetoplasmonic configurations. Different dispersion diagrams can be obtained for different modal waves. For both structures, there is a transmission band for frequencies below the plasma frequency, especially for extremely low frequencies, where in the absence of a magnetic field, wave transmission is impossible. There is no limit on the period of structure, the period of structure in the simulation varies from zero to 1.6λ_p.