Stochastic description of the light scattered by a polydisperse colloidal suspension: simulation and experiment

In this work, the stochastic properties of the detected signal in dynamic light scattering experiments are examined in light of Doob's theorem. For Markovian observations of the Brownian particle position, we prove from this theorem that the electric field scattered by a polydisperse suspension can be accounted for by a linear combination of Ornstein-Uhlenbeck processes. A new algorithm for generating the fluctuating field scattered by a polydisperse system is proposed from this alternative formalism. The statistics of our synthetic data is compared satisfactorily with that resulting from the experimental signal scattered by a binary suspension of polystyrene microspheres.