A spectral method based on surface plasmon resonance (SPR) in air is used to measure the dielectric function of a thin metal film. The method utilizes the spectral dependence of the ratio of the reflectances of p- and s-polarized waves measured in the Kretschmann configuration at different angles of incidence. By processing these dependences in the vicinity of a dip. or equivalently n... https://www.roneverhart.com/Roland-Blues-Cube-Stage-1x12-60-Watt-Combo-Amp-p24291/