Fig. 4: U-STED microscopy of core-shell UCNPs with topology-driven ETNs.
From: Topology-driven energy transfer networks for upconversion stimulated emission depletion microscopy
a Comparison of the theoretical and experimental resolution under dual-beam irradiation. Resolution is measured using a CW Gaussian-shaped excitation laser at 980 nm with an intensity of 0.03 MW cm−2 and an CW donut-shaped depletion laser at 808 nm at increasing intensity levels. Insets: confocal and U-STED microscopy images of 450-nm UCL emission of core-shell Tm@Yb@Y UCNPs with topology-driven ETNs under dual-beam irradiation. b Confocal and U-STED microscopy images of 450-nm UCL emission from core-shell Tm@Yb@Y UCNPs with topology-driven ETNs under dual-beam irradiation using a CW Gaussian-shaped excitation laser at 980 nm and an CW donut-shaped depletion laser at 808 nm. Magnified views are shown (red and blue boxes). The measured intensities of the CW excitation and depletion lasers at 980 nm and 808 nm are 0.03 MW cm−2 and 1 MW cm−2, respectively. Pixel dwell time: 10 ms. Scale bar: 1 μm. c Normalized UCL emission intensity profiles corresponding to the dashed red and blue lines in (b). d Detection of 450-nm UCL emission from core-shell Tm@Yb@Y UCNPs with topology-driven ETNs under dual-beam irradiation for different duration. Inset: confocal and U-STED microscopy images of 450-nm UCL emission after 0 minutes, 30 minutes, and 60 minutes of dual-beam irradiation
