Dipole emission and coherent transport in random media II. Density of states vs. index of refraction

TL;DR

This paper develops a microscopical approach to dipole emission in random media, relating decay rates to the medium's refractive index and analyzing emission enhancement or inhibition based on scatterer properties.

Contribution

It introduces a relation between decay rate and complex refractive index, and explores criteria for emission control and the nature of emitted power microscopically.

Findings

Decay rate linked to the complex refractive index.

Criteria for spontaneous emission inhibition/enhancement.

Discrepancies with previous interpretations of emission processes.

Abstract

This is the second of a series of papers devoted to develop a microscopical approach to the dipole emission process and its relation to coherent transport in random media. In this Letter, we deduce a relation between the transverse decay rate of an emitter in a virtual cavity and the complex refraction index of the host medium. We argue on the possibility of a criterion for inhibition/enhancement of spontaneous emission in function of the transition frequency and the correlation length of the host scatterers. In addition, we study the radiative/non-radiative nature of the net power emission through a microscopical analysis of the scattering events involved. This study reveals essential discrepancies with previous interpretations.