Optical transmission through strong scattering and highly polydisperse media

We present near infrared total transmission measurements through samples of randomly packed silicon powders. At different wavelengths we analyze in de tail the scattering properties and the effects of residual absorption. The loa est value of kl(s), where k is the wave vector and l(s) is the scatteri ng mean free path is 3.2. We also observe that kl(s) is nearly constant ove r a wide wavelength range. This phenomenon is associated with the high poly dispersity of the particles. We use the energy density coherent potenial ap proximation to explain our measurements.