| Square nickel mesh perforated with micron scale holes exhibits extraordinary transmission due to propagating surface plasmon polaritions (PSPP) combined with cavity modes. Propagating surface plasmon resonances are known to disperse with the angle of incident light and such experiments yield rich information regarding the plasmonics of the material. More accurate polarized Gamma X dispersion is presented within, as well as the first polarized Gamma M dispersion of square nickel mesh. Calculation of resonance positions within these experiments predicts an effective index of refraction for the asymmetric coupled surface plasmon polaritons to have a value of n'eff = 1.043. Gamma P and Gamma Q dispersion of hexagonal mesh is presented and the coupling of asymmetric plasmonic surfaces examined. Calculations allowing interactions between PSPP states of square mesh are compared with experimental results and traditional predictions of mesh, PSPP transmission maxima; explaining variation from experimental results and traditional predictions and illustrating the polariton, or mixed state, nature of PSPPs. Lastly, scatter free infrared spectra of sixty-three individual micron scale dust particles are presented by placement of each particle in a hole of plasmonic square nickel mesh. The constituents of each particle and the process of quantification of materials is examined by use of Mie scattering, Lorentz dispersion, and Bruggeman effective medium theories. The propagation lengths for PSPP resonances on such mesh are poor (∼1--2 hole-to-hole spacings), compared to smooth metal predictions or less absorbing metals, making this mesh ideal for studying individual particles. The PSPPs funnel light through the particles, but they are effectively isolated so long as the neighboring holes are empty. Saturation of absorption peaks at this scale are demonstrated. |
