Observability of acoustical and optical localization

Abstract

A ‘‘pseudosphere’’ approximation is introduced to describe quantitatively the localization of acoustic and optic waves. The localization length ξ is obtained in terms of experimentally accessible parameters (scatterer density and size, speed of sound or light, frequency). For d=3 it is predicted that acoustic Anderson localization will not be observed unless the scatterers are more efficitent than hard spheres. A phase diagram for the optic problem is obtained; it suggests the sudden onset of localization at moderate values of the scatterer density.