title: Hidden black: coherent enhancement of absorption in strongly scattering media.
abstract: We show that a weakly absorbing, strongly scattering (white) medium can be made very strongly absorbing at any frequency within its strong-scattering bandwidth by optimizing the input electromagnetic field. For uniform absorption, results from random matrix theory imply that the reflectivity of the medium can be suppressed by a factor ∼(ℓ(a)/ℓ)N(-2), where N is the number of incident channels and ℓ, ℓ(a) are the elastic and absorption mean free paths, respectively. It is thus possible to increase absorption from a few percent to >99%. For a localized weak absorber buried in a nonabsorbing scattering medium, we find a large but bounded enhancement.
authors: Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA. yidong.chong@yale.edu
authors: Y D
authors: YD
authors: Chong
authors: A D
authors: AD
authors: Stone