CW DPSS Lasers Make STED Microscopy More Practical

摘要

The diffraction of light has put an upper limit on the resolvability of alike objects in far-field fluorescence microscopy, as described by Abbe's law. In a standard confocal microscope, for example, the diffraction restricts the minimal extent of the excitation laser beam at the sample to about 200 nm in diameter for visible light. Scanning of this laser beam over the sample produces fluorescence images in which details smaller than this minimum spot size appear blurred (Figure la).