Fig. 1. Preparation flowchart of fluorescent ceramics.

Fig. 2. (a) XRD patterns of SA0, SA25, SA30, SA40, SA35V, and GAGG (PDF#46-0048); (b) Rietveld refinement of the SA35V; inset is the unit cell structure of Gd₃Al₃Ga₂O₁₂ showing coordination environment of Gd, Al, and Ga.

Fig. 3. SEM micrograph and elemental mapping pictures of SA35V.

Fig. 4. PLE and PL spectra of SA0, SA25, SA30, SA35, SA40, and SA35V.

Fig. 5. (a) TL curves of SA25, SA30, SA35, SA40; (b) comparison of TL curves and relative trap densities of SA0, SA35, and SA35V.

Fig. 6. TL curves with different heating rates of SA35V, and the trap depths.

Fig. 7. XPS spectra of the O 1s in SA0, SA35, and SA35V.

Fig. 8. (a) TL curves of SA0 and SA35V before and after air annealing; (b) EPR spectra of SA0 and SA35V after air annealing and SA35.

Fig. 9. Schematic of the optical storage mechanism of the GAGG:Ce³⁺, Yb³⁺.

Fig. 10. (a) Schematic illustration of the information storage and readout in ceramics; (b) and (c) the sample, with written information, is stimulated by 650 nm light and continuously stimulated for 1 min (with a filter); (d) and (e) the sample with written information is heated to 300°C and held at 300°C for 1 min.