Experimental apparatus for measurement of the angular, polarization, and wavelength dependence of light scattering from the visible to the infrared in bulk glass samples

Previous measurements of light scattering on bulk glass samples were made primarily at visible wavelengths. The scattering loss at longer wavelengths was then estimated by extrapolating the visible results, assuming a lambda(-4) (Rayleigh) dependence. This method can lead to a substantial uncertainty in the scattering loss at long wavelengths (> 2 mum). We have therefore constructed an experimental apparatus that measures the angular dependence of light scattered in both the Rayleigh and the Mie regimes from bulk glass samples at wavelengths between 0.6 and 2.6 microm. We have also developed a method of analysis of the angular scattering of both vertically and horizontally polarized beams to determine the Rayleigh ratios and dissymmetry factors as a function of wavelength. The average size of the scattering sites can be estimated in the range of 0.02 to 2.0 mum.