We consider the properties of surface plasmon polaritons (SPPs) in planar dispersive structures, in two particular cases: (1) a semi-bounded degenerate plasma (e.g., a metal), and (2) a heterogeneous structure consisting of a double-negative (DNG) and a single-negative (SNG) metamaterials separated by a dielectric slab.
For case 1, we obtain the dispersion and damping of SPPs, taking into account the spatial dispersion of a metal (due to quantum degeneracy of electrons) and electron-lattice collisions. We show that the spatial dispersion significantly affects the properties of SPPs: the collisionless damping of SPPs (due to spatial dispersion) is comparable to, or dominates over, the purely collisional (Ohmic) damping of SPPs (due to electron-lattice collisions) in a wide range of wavelengths, e.g., from infrared to extreme ultraviolet for SPPs in gold at room temperature. The spatial dispersion is also shown to affect the dispersion of SPPs, especially at short wavelengths (less than the collisionless skin depth, $\lambda\lesssim c/\omega_{p}$).
For case 2, we analyze the dispersion of TM and TE SPPs, accounting for temporal dispersion of the DNG and SNG metamaterials, and ignoring the dissipation and spatial dispersion. We obtain and solve numerically the dispersion equations for TM and TE SPPs for different dielectric slab thickness, obtaining a variety of "fast" and "slow" SPP modes supported by the considered heterogeneous metamaterial structure. In particular, we point out such potentially interesting features as mode splitting for finite slab thickness and regions of negative dispersion. Given the importance of the spatial dispersion for properties of SPPs in a semi-bounded metal (case 1), it would be interesting to also study the effect of spatial dispersion of metamaterials (ignored in case 2) on dispersion and damping of TM and TE SPPs in such structure.
For case 1, we obtain the dispersion and damping of SPPs, taking into account the spatial dispersion of a metal (due to quantum degeneracy of electrons) and electron-lattice collisions. We show that the spatial dispersion significantly affects the properties of SPPs: the collisionless damping of SPPs (due to spatial dispersion) is comparable to, or dominates over, the purely collisional (Ohmic) damping of SPPs (due to electron-lattice collisions) in a wide range of wavelengths, e.g., from infrared to extreme ultraviolet for SPPs in gold at room temperature. The spatial dispersion is also shown to affect the dispersion of SPPs, especially at short wavelengths (less than the collisionless skin depth, $\lambda\lesssim c/\omega_{p}$).
For case 2, we analyze the dispersion of TM and TE SPPs, accounting for temporal dispersion of the DNG and SNG metamaterials, and ignoring the dissipation and spatial dispersion. We obtain and solve numerically the dispersion equations for TM and TE SPPs for different dielectric slab thickness, obtaining a variety of "fast" and "slow" SPP modes supported by the considered heterogeneous metamaterial structure. In particular, we point out such potentially interesting features as mode splitting for finite slab thickness and regions of negative dispersion. Given the importance of the spatial dispersion for properties of SPPs in a semi-bounded metal (case 1), it would be interesting to also study the effect of spatial dispersion of metamaterials (ignored in case 2) on dispersion and damping of TM and TE SPPs in such structure.
Share it
