Cross-correlation laser scattering

Cross-correlation between two detectors was applied to analyze laser light-scattering fluctuations. Laser scattering from random concentration fluctuations is spatially coherent over small angular areas that are inversely proportional in size to the dimension of the scattering volume. By cross-correlating scattering intensity fluctuations in different angles, the correlation due to relaxation of concentration fluctuations is practically eliminated, and correlations reflecting changes in the scattering from the individual particles can be enhanced. Rotational diffusion of assymetric particles, conformational relaxation of random coils, and association-dissociation dynamics are determined here using the above approach.