Resolution scaling in STED microscopy

• DOI: 10.1364/oe.16.004154
• Publication Date: 2008-03-18T14:00:31Z
• Authors: Benjamin Harke; Jan Keller; Chaitanya K. Ullal; Volker Westphal; Andreas Schönle; Stefan W. Hell
• Keywords: 0303 health sciences; 03 medical and health sciences; Microscopy, Fluorescence; Image Interpretation, Computer-Assisted; Computer Simulation; Models, Theoretical; Image Enhancement; Algorithms

We undertake a comprehensive study of the inverse square root dependence of spatial resolution on the saturation factor in stimulated emission depletion (STED) microscopy and generalize it to account for various focal depletion patterns. We used an experimental platform featuring a high quality depletion pattern which results in operation close to the optimal optical performance. Its superior image brightness and uniform effective resolution <25 nm are evidenced by imaging both isolated and self-organized convectively assembled fluorescent beads. For relevant saturation values, the generalized square-root law is shown to predict the practical resolution with high accuracy.