Dependence of surface plasmon-phonon-polariton in 4 H-SiC on free carrier concentration

Abstract

In this paper, we present a thorough study of the characteristics of the surface modes that result from coupling between plasmon electronic oscillation modes, phonon modes, and electromagnetic modes. The Fourier transform of p-polarized reflectivity measurements were carried out on different 4 H-SiC epilayers differing in their free carrier concentration. The reflectivity measurements were performed with appropriate care to record reflectivity spectra averaged over a wide range of incidence angles. The complex infrared dielectric functions of the measured samples were determined by correcting the values obtained from the conventional Kramers-Kronig conversion technique with reference to Fresnel equations for reflectivity. The obtained dielectric functions were used to compute the effect of the free carrier concentration and the resulting plasmon electronic oscillation on the dispersion spectrum, lifetime, mean propagation length of the bulk, and surface plasmon-phonon-polariton modes. The effect of the free carrier concentration on the temporal coherence of surface plasmon-phonon-polariton is investigated, showing a potential practical method for enhancing the temporal coherence of SiC based thermal sources. © 2017 Author(s).