Enhanced microwave and far IR absorption of nanometer thin conductive films in the case of total internal reflection

Abstract

This paper presents a numerical analysis, using the rigorous-coupled-wave-analysis method, of microwave and far-IR radiation scattering on thin conductive films of nanometer thickness under the condition of total internal reflection. Transmittance, reflection, and absorption studies have shown the possibility of overcoming the 50% absorption limit with frequency-independent behavior; the absorption above the critical angle reaches values greater than 90%. In addition, the influence of such thin metal-dielectric structure on the Goos–Hänchen shift is considered. At maximum absorption, calculations showed its absence in both TE and TM polarizations. The numerical analysis was carried out for a plane wave and for a 500 cm diameter beam.