Optics and Photonics Society of Iran

In this paper the condition for surface plasmon excitation and also surface plasmon polariton dispersion relation between an isotropic plasmonic medium and a birefringent medium in TM is considered. For simplicity, it is supposed that one of optical axes is laid on the interface and the other two axes are rotated about it by an arbitrary angle θ. Maxwell’s equations are used to derive the relations. It is found that condition for the formation of surface plasmon and the dispersion relation are functions of θ and the dispersion relation has a linear functionality with respect to the frequency and the wavenumber. The slope of dispersion relation is dependent on the optical properties and also orientation of the principal axes. The trend of change of plasmon frequency as a function of θ is related to the positive or negative sign of dielectric constant difference of rotated principal axes.