Far-field fluorescence nanoscopy of diamond color centers by ground state depletionE. Rittweger, D. Wildanger and S. W. Hell
Max Planck Institute for Biophysical Chemistry - Am Fassberg 11, 37077 Göttingen, Germany, EU
received on 14 March 2009; accepted in final form by V. Dose on 17 March 2009; published April 2009
published online 2 April 2009
We report on two modalities of lens-based fluorescence microscopy with diffraction-unlimited resolution relying on the depletion of the fluorophore ground state. The first version utilizes a beam with a deep intensity minimum, such as a doughnut, for intense excitation followed by mathematical deconvolution, whereas in the second version, a regularly focused beam is added for generating the image directly. In agreement with theory, the subdiffraction resolution scales with the square root of the intensity depleting the ground state. Applied to the imaging of color centers in diamond our measurements evidence a resolving power down to 7.6 nm, corresponding to 1/70 of the wavelength of light employed. Our study underscores the key role of exploiting (molecular) states for overcoming the diffraction barrier in far-field optical microscopy.
42.30.-d - Imaging and optical processing.
07.60.Pb - Conventional optical microscopes.
71.55.-i - Impurity and defect levels.
© EPLA 2009