Fig. 1. Rare earth ion-doped glass ceramic fibers fabricated by double crucible method, rod-in-tube method, and melt-in-tube method^[10-11,13]. (a) Schematic of double crucible method; (b)(c) photos of a glass rod before and after drawing process by rod-in-tube method; (d) schematic of melt-in-tube method; (e)(f) cross section of a glass fiber made by melt-in-tube method and cor

Fig. 2. Optical performance of rare earth ion-doped oxyfluoride glass ceramic fibers^[14,17-18]. (a)-(d) TEM images of the glass ceramic fibers heat-treated at different temperatures; (e) 1.53 μm near-infrared (NIR) emission spectra of Er³⁺ singly and Er³⁺/Yb³⁺ co-doped samples; (f) cutback measurement of the precursor glass fibers and glass cera

Fig. 3. Research progress in whispering gallery mode lasers with rare earth ions-doped oxyfluoride glass ceramic microcavities^[33-35]. (a) Lasing spectra of the microcavity with a bottle-like geometry, the insets show the images of the microcavity under different excitation power; (b) scanning electron micrograph of a polystyrene bead coated with Tm³⁺ doped fluoride nanocrystals;(c)(d) the corresponding r

Fig. 4. Research progress in random lasers with rare earth ions-doped oxyfluoride glass ceramics^[45-47]. (a) (b) TEM image of the glass ceramic film with Ag nanoparticles and the corresponding random lasers emission spectrum pumped by a pulsed laser; (c) XRD patterns of the glass ceramic with Ba₂LaF₇ nanocrystals heat-treated at different temperatures; (d)(e) random lasing spectra of the glass