Far-field optical nanoscopy of diamond color centers

This article shows the capability of imaging nitrogen vacancy (NV) centres with nanoscale resolution and Angstrom precision using focused visible light, through stimulated emission depletion (STED) microscopy. The optical control of the population of their excited state at the nanoscale using conventional lenses expands the versatility of these centres and demonstrates the suitability of STED to image dense color centers in crystals. NV defects show great potential as tags for far-field optical nanoscopy as they exhibit nearly ideal STED without bleaching. Measured point spread functions of 5.8 nm lateral FWHM demonstrate an all-physics-based far-field optical resolving power exceeding the wavelength of light by about 100-fold.