2-COLOR DYNAMIC LIGHT-SCATTERING
 
                                      SEGRE PN, VANMEGEN W, PUSEY PN, SCHATZEL K, PETERS W
                                                                   JOURNAL OF MODERN OPTICS
                                                                       42: (9) 1929-1952 SEP 1995
 
                                                                                    Abstract:
The design, alignment and operation of improved two-colour dynamic light scattering equipment which effectively
suppresses multiple scattering and allows the study of the Brownian dynamics of optically turbid samples is
described. The technique operates by cross-correlating scattered light of two different colours. With the
appropriate scattering geometry, only singly scattered light contributes to the time-dependent part of the measured
intensity cross-correlation function thus allowing straightforward interpretation of the data. To demonstrate the
performance of the instrument we have studied various colloidal suspensions. Although dilute enough that free
diffusion of the particles can be assumed, the samples ranged from quite transparent to distinctly turbid. We have
confirmed that the measured cross-correlation functions accurately reflect only single scattering even in the
presence of strong multiple scattering.