FIBER OPTIC DYNAMIC LIGHT-SCATTERING, NEITHER HOMODYNE NOR HETERODYNE

Homodyne and heterodyne fiber-optic dynamic light scattering (FODLS) techniques are studied using concentrated dispersions of monodisperse latices. It is shown that pure homodyne or heterodyne detection cannot be achieved in many situations. Analysis of the data with a singular value decomposition method shows that the results may constitute a homodyne and a heterodyne contribution. The proportion of both contributions can be calculated from the intercept of the autocorrelation function (ACF). If the ratio between both contributions is known, the field ACF can be calculated from the data. This method is used to analyze measurements of monodisperse latices and of binary mixtures of monodisperse latices.