THERMAL RADIATION REVISITED IN THE NEAR FIELD

摘要

Thermal radiation is the radiation emitted by a body at temperature T. Radiative heat transfer between two bodies is described by emission and absorption of photons. If one studies the electromagnetic field in the close vicinity of a surface, the usual theory for radiative heat transfer breaks down It does not allow to explain the large density of radiative energy within nanometers of the interface. It does not explain the enhancement of the flux between two particles or two interfaces separated by a few nanometers. The purpose of this paper is to give a short review of radiative heat transfer at nanoscale and to serve as a guide in the literature. The first part of the paper is devoted to the description of the energy density close to an interface The second part of the paper describes the possibility of producing so-called coherent thermal sources which are surfaces that emit radiation in a very well-defined direction The third part of the paper addresses the radiative heat transfer at nanometer scale.