General theory of light scattering in solids

Abstract

-4 theory of light scattering is dereloped which uses consequent.ly the connection between the scattered light and the fluctuations of the electromagnetic field. -4 general forniuln. is given expressing t,he Scattering cross-section in ternis of the fluctuations of the electrical conduct,ivity operator. and by applying the dissipation-fluctuation theorem in terms of the conductivity operator itself. It is shown how the common representations of the scattering cross-section can be derived from the general theory.Es wird eine allgemeine Theorie dcr Lichtstreuang entaickelt, in der die Beziehurig zwischen dein gestreuten Licht und den Flukt.ua.tionen des elektromagnetischen Feldcs Ironsequent genutzt wird. Mit Hilfe einer allgemeinen Formel kann der Streuquerschnitt durch die Fluktmtionen des elektrischen Leitfahigkeitsoperators ausgedriickt werden und. nach Bnwendang des DissipationsFlaktuibtionstheorems, durch den Leitflhigkeitsoperator selbst. Es wird gezeigt,, wie die iiblichen Darstellungen des Streuquerschnitts aus der allgemeinen Theorie abgeleitet. werden kiinnen.

Theory of photoluminescence in semiconductors

“…According to Enderlein et al, 3 the Poynting vector of the electromagnetic radiation ͗Ê ϫĤ ͘ consists of a coherent part ͗Ê ͘ϫ͗Ĥ ͘ and an incoherent part ͗⌬Ê ϫ⌬Ĥ ͘. While the coherent part describes the propagation of macroscopic electromagnetic fields, the incoherent part contains the secondary emission.…”

“…2 This theory was applied by Enderlein et al to optical processes in semiconductors and the statistical properties of the secondary emission were traced back to correlation functions of the electronic system. 3 During the last fifteen years, the method of Green's functions has been successfully applied to optical properties in semiconductors, including Coulomb interaction. 4 Recent theoretical papers used these concepts for the description of the luminescence properties.…”

Green's Function Approach to Photoluminescence in Semiconductors

“…Following Enderlein et al [9], spontaneous emission is characterized by a Poynting vectorDE Â DĤ, where the operators DÊ and DÊ represent the the fluctuations of the electromagnetic field around the mean value. The measurable part of the Poynting vector must contain the operators in normal order, i.e., S 1 2 hDÊ Â DĤ À h:c:i, where the superscripts AE indicate contributions proportional to exp AEiwt for w > 0 [10].…”

General Theory of Secondary Radiation in Condensed Matter

“…The latter is a comparison of results 11131 to those of other authors. I n particular, the main formula for the scattering cross-section was obtained in [24] with the help of quite different method: by correlating the scattered light intensity to the fluctuations of the electromagnetic field with the requirement that the exciting light interacts with the medium. Generally speaking, the main formulas obtained in [13, 241 differ from each other.…”

“…Considering the state of the electromagnetic field, due to a certain number of quanta N , , we suppose the exciting radiation to be not coherent, because the phase of the electromagnetic wave in the states with certain quanta is indefinite. This approach is equivalent to that of [24], where the phase of the exciting electromagnetic wave was supposed to be definite (the radiation was coherent) but averaging was performed over a time interval larger than the reciprocal frequencies of exciting or scattered radiation. …”