European XFEL Seminar

Dynamic speckle techniques: new algorithms and applications

by Marcelo Trivi (Centro de Investigaciones Opticas, La Plata Argentina)

E2.096 (Campus Schenefeld, Main Building(XHQ))


Campus Schenefeld, Main Building(XHQ)

Dynamic laser speckle (DLS) is an optical technique that has been used for several applications in biology, medicine and industry. It is based on a scattering phenomenon occurring when coherent laser light illuminates an active surface. The surface appears to be covered by tiny bright and dark dots that fluctuate in a seemingly random way as for a boiling liquid, according with the surface fluctuation. Thus, the study of the temporary evolution of the speckle patterns may provide an interesting tool to characterize the parameters involved in the sample dynamic processes. Many new applications have been recently developed. In this seminar, Marcelo Trivi will show a brief account of the basic concepts of the (DLS) technique, with focus on developments both with new algorithms for characterization of the phenomenon as well as new applications: vortex and island analysis for low dynamic speckles activity, studies of spatial-temporal patterns using principal component analysis, image segmentation using Self-Organizing Maps among the others. About applications: studies of chemotaxis towards hydrocarbons and maize hardness, for the characterization of electrotechnical-porcelain, hydro-adsorption processes in clay surfaces for catalysis applications and measurements of shrinkage during photopolymerization of methacrylate resins used in dentistry. A short discussion about the usage of such algorithms in case of European XFEL experiments will be proposed.