Raman Scattering from the Upper Mode of Surface Polaritons in a Layered Structure

Abstract

We report the first observation of the upper mode of surface polaritons in a three component layered structure composed of a GaAs film on a sapphire substrate. By changing the external medium from the air to benzene, we could detect a change in the dispersion relation. The observed dispersion of the upper mode agrees with theoretical predictions within the experimental uncertainty. The observation was made possible through the use of a digital background subtraction technique.