Spectral selectivity of cermets with large metallic inclusions

In order to address the problem of the optical reflectance of cermets beyond the quasistatic dipolar limit, we consider Monte Carlo multiple scattering simulations as well as a radiative transfer study. Slabs of alumina with inclusions of Cu, Au, Co and Cr are studied; reflectance coefficients are calculated as a function of wavelength, considering metal inclusion diameters up to 2.0 mu m. We show that despite the incoherent diffuse propagation of light inside the slab, strong selectivity is achieved by particle diameters around 0.2 mu m, even for very low metal concentrations. (C) 1998 American Institute of Physics.