Photon Correlation Measurements at Large Lag Times: Improving Statistical Accuracy

Dynamic light scattering and photon correlation spectroscopy are able to resolve large ranges of coherence times, and hence of scattering particle size or constant of diffusion, in a single measurement if a modern multiple-tau correlator is used. However, particular problems like bias and unsatisfactory statistical accuracy typically arise at very large lag-times. A novel normalization scheme is presented which cures the accuracy problem and provides reliable photon correlation data at large lag-times within significantly reduced total measurement times.