Berlin 2014 – wissenschaftliches Programm
Q 30: Poster: Photonics, laser development and applications, ultrashort laser pulses, quantum effects
Q 30.30: Poster
Dienstag, 18. März 2014, 16:30–18:30, Spree-Palais
Nanoparticle characterization by laser transmission microscopy — •Irene Neugebauer, Markus Selmke, and Frank Cichos — Fakultät für Physik und Geowissenschaften, Universität Leipzig, Deutschland
Optical transmission microscopy setups have been used to study small particles under tightly focused illumination. Detailed works about sensitive techniques like photothermal single particle microscopy and spatial modulation spectroscopy are available. The self-interference of the incidence beam with the scattered field here provides a contrast. The signal contains detailed information about the scatterer itself and the illuminating focused field point-spread-function. So far, there is no convenient framework for the precise description of such transmission signals of nanoparticles other than Rayleigh scatterers. We introduce a concise extension of the generalized Lorenz-Mie theory which allows us to characterize nanoparticles and focus fields by means of such transmission signals. We demonstrate the capability to robustly map out the illuminating point-spread-function and analyze the change of transmission while we use different apertures in the detection path.