Nanoscale Imaging with Focussed Visible Light
Dr. Volker Westphal (Max-Planck-Institut für Biophysikalische Chemie, Abteilung NanoBiophotonik)

Stimulated emission depletion (STED) microscopy is a recently developed method to break the diffraction resolution barrier in far-field fluorescence microscopy.
Single molecules can serve as point-like probes to quantify the resolution.
Here, we demonstrate sub-diffraction resolution of better than 20 nm in STED microscopy. Measurement of the optical transfer function in the focal plane reveals an about 10-fold enlargement of the spatial bandwidth over Abbe’s limit. The attained resolution represents a new benchmark in far-field microscopy and underscores the viability of fluorescence nanoscopy with visible light and conventional optics.

Furthermore we present a simple all-laser-diode STED microscope that shows a five-fold increase in resolution.

We will conclude with the application of this technique in biology and lithography.