Introduction to Thermal Radiation and Surface Polaritons

Aiming at understanding and quantifying planar thermal radiation along surfaces and films, we contextualize this mechanism within the broader frame of radiative heat transfer and resonant surface waves. The intrinsic link between these domains lies in the electromagnetic waves governed by Maxwell’s equations. However, accurately defining thermal radiation using Maxwell’s equations necessitates tackling the complexities of the Fluctuation Dissipation Theorem, particularly challenging in complex and multipolar geometries. Our approach involves simplifying the intricate three-dimensional problem posed by stochastic thermal emission of electromagnetic waves in confined systems. We achieve this clarification by reducing the problem to the kinetic propagation of photon packets, described by the two-dimensional Radiative Transfer Equation.