Fig. 4: wr-PNDs based water-proof two-photon pumped lasers.
From: Water-resistant perovskite nanodots enable robust two-photon lasing in aqueous environment
a Pumping configuration used in two-photon lasing measurements. b Jablonski diagram of the two-photon absorption and emission in wr-PNDs and PQDs. c Relative PLQYs of the laser devices (measured in an integrating sphere under 375 nm laser excitation) based on wr-PNDs (red dots) and pristine PQDs (black dots), which were immersed in water for different periods of time. The insets are the photographs of the wr-PNDs-based laser in water taken at different time under UV light illumination. d Emission spectra and e integrated intensity and emission FWHM for the wr-PNDs-based laser immersed in water for 13 h, as a function of pumping intensity under 800 nm fs laser excitation. The insert in d sketches the capillary-like microcavity laser device. f Emission spectra and g integrated intensity of the wr-PNDs-based random laser device stored in water for 15 days. Source data are provided as a Source Data file.
