ANALYSIS OF DYNAMIC LIGHT-SCATTERING SIGNALS WITH DISCRETE WAVELET TRANSFORMATION

The analysis of non-stationary signals calls for specific tools which go beyond classical Fourier analysis. Here we present the discrete wav elet transform as a quantitative method to analyse the scaling propert ies of non-stationary and chaotic signals obtained by light scattering . The analysis is performed directly on the time-resolved scattered in tensity. The result is the scaling exponent of the underlying power sp ectrum and the frequency window where the scaling can be observed. The se properties are obtained with a higher accuracy and in a fraction of the time compared with the classical method of intensity correlation functions. As a test we applied the new method to the sol-gel transiti on of a suspension of disc-shaped colloidal particles in water.