Photon correlation spectroscopy (PCS) is routinely used to investigate the dynamics of colloidal particles undergoing Brownian motion. This technique is applicable to low-density colloidal suspensions in which the effects of multiple light scattering are minimal. We introduce a new low-coherence heterodyne PCS technique that allows direct investigation of colloidal suspensions of higher concentration than previously accessible with standard PCS. In this technique, low-coherence optical heterodyne interferometry is used tosuppress multiple light scattering, allowing preferential detection of single-scattering events.
© 1998 Optical Society of America
Joshua H. Johnson, Shannon L. Siefken, Aaron Schmidt, Robert Corey, and Paul Saulnier, "Low-Coherence Heterodyne Photon Correlation Spectroscopy," Appl. Opt. 37, 1913-1916 (1998)