Suppression of multiple scattering by photon cross-correlation techniques

The effectiveness of cross-correlation schemes for suppressing multiple sca ttering in light scattering measurements has been demonstrated convincingly . Thus, measurements on turbid samples can be analysed as though the sample s were transparent, i.e. exhibiting only single scattering. The methods are now being used for new research, particularly in the study of concentrated colloidal dispersions. This article reviews the current state of the field with emphasis on the two-colour and three-dimensional dynamic light scatte ring techniques. Although these methods were originally designed to suppres s multiple scattering in dynamic light scattering, it has recently been rec ognised that they are also effective in static light scattering. The cross- correlation schemes are compared briefly with other light-scattering method s for studying turbid and opaque samples such as fibre-optic probes and dif fusing wave spectroscopy. (C) 1999 Elsevier Science Ltd. All rights reserve d.