Professor Andrey Chabanov

University of Texas at San Antonio

Photon Localization in Disordered Media

Abstract: Localization is inherently a wave interference phenomenon and may therefore occur for both classical and quantum mechanical waves. It may be considered for all manner of excitations including electromagnetic, sound and ultrasound, acoustic and optic phonons, surface plasmons, polaritons, electrons and atoms. Signatures of localization are observed in a constellation of transport phenomena which reflect the transition from diffusive to localized waves. For example, the dimensionless conductance and the ratio of the typical spectral width and spacing of quasimodes are key indicators of electronic and classical wave localization when inelastic processes are absent, whereas the statistics of transport are used to determine localization in the presence of absorption. The intertwined effects of localization and absorption can also be disentangled in the time domain since all waves emerging from the sample at a fixed time delay from an exciting pulse are suppressed equally by absorption. In this talk, we will discuss our steady-state and pulsed measurements of electromagnetic localization in low-density collections of disordered dielectric spheres contained in a metal tube (i.e., in quasi-1D geometry), and how the photon localization can be understood in the context of mesoscopic transport theory.