A specific experimental Laser Scattering Tomography (LST) acquisition
procedure is presented. It is adapted to the characterization of materials
containing scattering defects ranging from 1 to 102/mm3. The technique
makes it possible to obtain good resolution within a volume chosen to contain
a statistically significant defect density. This method is used to show that
the gas levitation technique makes it possible to significantly decrease
scattering defects in glasses. In parallel, individual study of defects in
such glasses is also presented.