Accuracy preserving methods for faster measurements with Dynamic Light Scattering and Diffusing Wave Spectroscopy

摘要

Dynamic Light Scattering together with Diffusing Wave Spectroscopy are common and well acknowledged techniques to study micro and macro dynamics of a complex media. In the past these methods were successfully applied for the characterization of colloidal panicles of different kind, foam, sand, interfacial boundaries, blood cells etc. The shape and decay of auto-correlation function (ACF) of scattered light intensity fluctuations are used to study the type and time scale of scatters dynamics. This is usually done by collecting the light by a point-like detector for a time period much larger than the correlation time. But in case of slow or arrested scatter motion the obtained time-averaged ACF may depend on the detector position (non-ergodicity problem). Special averaging techniques required for this case are presented in the current paper.