Abstract

There is a rich variety of systems in nature which are essentially dense aggregations of particle-like structures whose positions vary randomly in space and time. Unfortunately because the particles often scatter light strongly, progress in our understanding of fluctuating, random media has been limited to very dilute systems. Recently, a number of researchers have developed and applied a new spectroscopy to study the properties of colloidal suspensions which multiply scatter light [1]. This method, called diffusing-wave spectroscopy (DWS), exploits the diffusive nature of light transport in strongly scattering media to relate temporal intensity fluctuations of the scattered light to average particle motion. In contrast to traditional quasi-elastic light scattering methods, DWS probes particle motion in dense, strongly scattering colloids and over length scales much shorter than the wavelength of light (<10Å).

© 1992 Optical Society of America