Multiple-Scattering-Free Light-Scattering: Two-Color Cross-Correlation Light-Scattering Apparatus

Phys. Rev. E 85, 031401 (2012), German Patent DE102012021752-A1

Light-scattering (LS) is one of the most powerful tools in soft matter physics to study single particle properties as well as structure, kinetics and dynamics of the system of interest.

Unfortunately multiple scattering often complicates the data evaluation. A classy way to circumvent multiple scattering effects in LS data is provided by cross-correlation techniques. Here two identical but distinguishable dynamic light scattering experiments are performed simultaneously on the same scattering volume. This is a major challenge to the mechanical and optical design of the setup.

Using a home-made concentric four arm goniometer, combined with fiber optical illumination and detection we realized a small and compact two color cross-correlation light-scattering setup. Multiple scattering is sufficiently suppressed allowing the determination of multiple scattering free dynamic structure factors as well as particle form and structure factors.