Interferometric Nanoparticle Tracking

This biophysics-oriented project explores the potential of phase- and amplitude-resolved spectroscopy to study dynamical properties of nanoscale objects in the visible range with sub-wavelength resolution. Heterodyne techniques allow to visualize trajectories of single nano- particles (Au spheres, semiconductor quantum dots) and tagged macromolecules in aqueous solution with low-level light intensities. We work towards a multi-color extension of this minimal invasive linear optical method, with 3-d spatial (< λ/10) and temporal (< 100 μs) resolution.