QED in arbitrary linear media: Amplifying mediaC. Raabe and D.-G. Welsch
Theoretisch-Physikalisches Institut, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
Published online: 18 June 2008
Recently, we have developed a unified approach to QED in arbitrary linearly responding media in equilibrium-media that give rise to absorption [Phys. Rev. A 75, 053813 (2007)]. In the present paper we show that, under appropriate conditions, the theory can be quite naturally generalized to amplifying media the effect of which is described within the framework of linear response theory. We discuss the limits of validity of the generalized theory and make contact with earlier quantization schemes suggested for the case of linearly and locally responding amplifying dielectric-type media. To illustrate the theory, we present the electromagnetic-field correlation functions that determine the Casimir force in the presence of amplifying media.
© EDP Sciences, Springer-Verlag 2008