Sub-diffraction imaging of nitrogen-vacancy centers in diamond by stimulated emission depletion and structured illumination

Stimulated emission depletion (STED) and structured illumination (SIM) are two commonly used techniques for super-resolution imaging. However, the performance of these two techniques has never been quantitatively compared side-by-side. Taking advantage of the non-photobleaching characteristic of NV centres in fluorescent nanodiamond (FND), we performed a comparative study for the resolution of these two methods with 35 nm FNDs at the single particle level, as well as with FND grown in bulk diamond material. Results show that STED provides more structural details, whereas SIM provides a larger field of view with a higher imaging speed. SIM may induce deconvolution smooth and orientational artifacts during its post-processing.