%0 Journal Article
%T STED Nanoscopy with Time-Gated Detection: Theoretical and Experimental Aspects
%A Giuseppe Vicidomini
%A Andreas Sch£¿nle
%A Haisen Ta
%A Kyu Young Han
%A Gael Moneron
%A Christian Eggeling
%A Stefan W. Hell
%J PLOS ONE
%D 2013
%I Public Library of Science (PLoS)
%R 10.1371/journal.pone.0054421
%X In a stimulated emission depletion (STED) microscope the region in which fluorescence markers can emit spontaneously shrinks with continued STED beam action after a singular excitation event. This fact has been recently used to substantially improve the effective spatial resolution in STED nanoscopy using time-gated detection, pulsed excitation and continuous wave (CW) STED beams. We present a theoretical framework and experimental data that characterize the time evolution of the effective point-spread-function of a STED microscope and illustrate the physical basis, the benefits, and the limitations of time-gated detection both for CW and pulsed STED lasers. While gating hardly improves the effective resolution in the all-pulsed modality, in the CW-STED modality gating strongly suppresses low spatial frequencies in the image. Gated CW-STED nanoscopy is in essence limited (only) by the reduction of the signal that is associated with gating. Time-gated detection also reduces/suppresses the influence of local variations of the fluorescence lifetime on STED microscopy resolution.
%U http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0054421