title: Easy-use and low-cost fiber-based two-color dynamic light-scattering apparatus.
abstract: We present a small and compact two-color cross-correlation light-scattering setup designed to study the structure and dynamics of colloidal suspensions in the regime of considerable turbidity. Using a homemade concentric four-arm goniometer, combined with fiber-optical illumination and detection devices, allows an easy and long time stable alignment-even under a temperature variation of ∼5 °C. Tests with a nearly multiple scattering free suspension of small Rayleigh scatterers show intercepts in cross correlation near 0.4 over a wide range of scattering angles from 20° to 150°. Measuring slightly turbid samples in cross-correlation mode multiple scattering is sufficiently suppressed allowing the determination of multiple scattering free dynamic structure factors as well as particle form factors.
authors.affiliation: Institut für Physik, Johannes Gutenberg-Universität Mainz, Mainz, Germany.
authors.forename: Achim
authors.initials: A
authors.lastname: Lederer
authors.forename: Hans Joachim
authors.initials: HJ
authors.lastname: Schöpe
mesh_terms: D003116:Color; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008027:Light; D008029:Lighting / Q000295:instrumentation*; D009391:Nephelometry and Turbidimetry / Q000295:instrumentation*; D012031:Refractometry / Q000295:instrumentation*; D012542:Scattering, Radiation