Vortrag im Rahmen der Chemisch Physikalischen Gesellschaft
Colloids are systems in which a material is finely dispersed in another one. Examples are: paint, toothpaste, smoke, drinking water, sewage, cell cultures and blood. The dispersed objects interact via various forces, such as van der Waals attractions and charge interactions and may be actively swimming: all this leads to collective phenomena such as rapid phase transitions. We look at that with in-line holographic microscopy. Here, monochromatic light is scattered by dispersed particles or microorganisms. The scattered light interferes with the ballistic part of the illumination, forming holograms. We introduce a family of interference contrasts and a thresholding scheme that boost both the signal-to-noise ratio and resolution allowing the swift detection and characterization of thousands of individual objects in large volumes of liquid. This gives access to colloidal interactions in great detail and enables the monitoring of real world problems such as food hygiene and processes in bioreactors. To make the latter possible at scale we founded a startup company.
