Prismless excitation of surface plasmons in the infrared spectral region by ATR

Abstract A configuration for the excitation of surface plasmons in the infrared spectral region using ATR but without a coupling prism is presented. The technique is to place between the metal and the air a material which has a lower index of refraction than air so that the standard total internal reflection geometry is recovered. Experiments are performed using an aluminium layer as surface plasmon active material covered by a thin layer of quartz to realize the coupling in the reststrahlen region. The spectra are taken with the help of an ellipsometric Fourier-transform spectrometer. The behavior of the ellipsometric parameters and the degree of polarization around the surface plasmon resonance is discussed.