FIBER OPTIC DYNAMIC LIGHT-SCATTERING, NEITHER HOMODYNE NOR HETERODYNE

Homodyne and heterodyne fiber-optic dynamic light scattering (FODLS) t echniques are studied using concentrated dispersions of monodisperse l atices. It is shown that pure homodyne or heterodyne detection cannot be achieved in many situations. Analysis of the data with a singular v alue decomposition method shows that the results may constitute a homo dyne and a heterodyne contribution. The proportion of both contributio ns can be calculated from the intercept of the autocorrelation functio n (ACF). If the ratio between both contributions is known, the field A CF can be calculated from the data. This method is used to analyze mea surements of monodisperse latices and of binary mixtures of monodisper se latices.