Photon-Weight-Reallocated Stimulated Emission Depletion Nanoscopy

A novel optimization concept called “photon weight reallocation” is proposed to evaluate the significance of individual photons in an image, filtering out useless photons while preserving effective ones. This process aims to minimize background noise and enhance the resolution of the image. By leveraging a honeycomb array detector and fluorescence lifetime detection, photon weight reallocation is implemented in stimulated emission depletion (STED) nanoscopy through the fusion of the spatial and temporal photon weights. This approach yields exceptional results in terms of background and noise suppression and resolution enhancement. The experimental results demonstrate significant improvements in both the signal-to-background ratio and peak signal-to-background ratio within dense sample areas of STED after applying the photon-weight-reallocation process, achieving maximum improvements by factors of 8.9 and 37.3, respectively. Besides, the axial and lateral resolutions of STED are improved by factors of 1.55 and 1.36, respectively, following this process.