Anderson localization of partially-incoherent light

TL;DR

This paper investigates how partial incoherence affects Anderson localization of light in disordered media, revealing that incoherence delays localization but does not prevent eventual exponential localization in low-dimensional systems.

Contribution

It demonstrates that partial incoherence delays but does not inhibit Anderson localization, and shows the asymptotic similarity between incoherent and coherent wave behavior.

Findings

Incoherence delays localization in disordered media.

Partially-incoherent waves eventually localize exponentially.

Asymptotic behavior of incoherent beams resembles coherent realizations.

Abstract

We study Anderson localization and propagation of partially-spatially incoherent wavepackets in linear disordered potentials, motivated by the insight that interference phenomena resulting from multiple scattering are affected by the coherence of the waves. We find that localization is delayed by incoherence: the more incoherent the waves are, the longer they diffusively spread while propagating in the medium. However, if all the eigenmodes of the system are exponentially localized (as in one- and two-dimensional disordered systems), any partially-incoherent wavepacket eventually exhibits localization with exponentially-decaying tails, after sufficiently long propagation distances. Interestingly, we find that the asymptotic behavior of the incoherent beam is similar to that of a single instantaneous coherent realization of the beam.