Midinfrared scattering and absorption in Ge powder close to the Anderson localization transition

Using a free electron laser we have performed midinfrared transmission and reflection measurements in strongly scattering Ge powder. We have studied the wavelength dependence of the scattering properties and the optical absorption. Results indicate that our samples are close ${(kl}_s\simeq 3)$ to the Anderson localization transition but still above it. This is in contrast to the recently reported strong localization of light ${(kl}_s<1)$ in a similar powder of lower refractive index particles (GaAs).