Fig. 1. Optical paths. (a) Optical path for two-photon fluorescence; (b) optical path for open-aperture Z-scan

Fig. 2. TEM images of G₁₆ under different rulers. (a) 20 nm; (b) 2 nm

Fig. 3. Spectra of samples. (a) Raman spectra of samples under different heat treatment time; (b) absorption spectra of samples under different heat treatment time (inset: physical pictures of samples); (c) normalized fluorescence spectra of samples at 400 nm (inset: fluorescence emission phenomena of samples illuminated by 400 nm monochromatic light and full width at half maximum; (d) fluorescence spectra of sample G₁₆ under different excitation wavelengths

Fig. 4. Fluorescence spectra of samples G₈ and G₁₆ under different situations. Normalized fluorescence spectra of (a) G₈ and (b) G₁₆ pumped by 400 nm monochromatic light and excited by 800 nm femtosecond laser; (c) up-conversion fluorescence spectra of G₁₆ excited by (c) 800 nm and (d) 960 nm lasers with different powers (inset: double loglinear fitting of fluorescence intensity I and pump power P)

Fig. 5. Mechanism of nonlinear absorption of CdTe quantum dots doped glass. (a) Schematic of carrier relaxation processes; (b) open-aperture Z-scan data and fitting results