Multi-focal laser fabrication of nitrogen vacancy centres in a bulk diamond

We demonstrate the multi-focal fabrication of single NV- centres at different depths in a bulk diamond. After performing an annealing process, the optically detected magnetic resonance (ODMR) signal is measured to confirm the generation of NV- centres. These emitters are photo-stable and are imaged by using three different excitations wavelengths at different depths close to the bulk diamond surface. Using two-photon microscopy, the NV- centres are imaged with a resolution down to 0.36 mu m to study the effect of the exposure time of the multi-focal laser writing on the spatial resolution of each fabrication. The Hanbury Brown and Twiss (HBT) test is performed with two-photon excitation to study the number of NV- centres at the location of each multi-focal fabrication. We demonstrate the formation of single NV- centres placed between 100 nm and 3 mu m below the diamond surface. The ability to control the placement of single NV- centres with depth is of paramount importance for applications in quantum information, single spin magnetometry, and optical data storage. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement