Density of states and extinction mean free path of waves in random media: dispersion relations and sum rules.
We establish a fundamental relationship between the averaged local density of states and the extinction mean free path of waves propagating in random media. From the principle of causality and the Kramers-Kronig relations, we show that both quantities are connected by dispersion relations and are constrained by a frequency sum rule. The results should be helpful in the analysis of wave transport through complex media and in the design of materials with specific transport properties.
Carminati
R
R
Institut Langevin, ESPCI, CNRS UMR 7587, Laboratoire d'Optique Physique, 10 rue Vauquelin, 75231 Paris Cedex 05, France. remi.carminati@espci.fr
Sáenz
J J
JJ