Optical far-field super-resolution microscopy using nitrogen vacancy   center ensemble in bulk diamond
  We demonstrate an optical far-field super-resolution microscopy using array of nitrogen vacancy centers in bulk diamond as near-field optical probes. The local optical field, which transmits through the nanostructures on the diamond surface, is measured by detecting the charge state conversion of nitrogen vacancy center. And the locating of nitrogen vacancy center with spatial resolution of 6.1 nm is realized with the charge state depletion nanoscopy. The nanostructures on the surface of diamond are then imaged with resolution below optical diffraction limit. The results offer an approach to built a general-purpose optical super-resolution microscopy and a convenient platform for high spatial resolution quantum sensing with nitrogen vacancy center. 
Shen Li, Xiang-dong Chen, Bo-Wen Zhao, Yang Dong, Chong-Wen Zou,   Guang-Can Guo, and Fang-Wen Sun
physics.optics