$\mathrm{Ca}{\mathrm{F}}_2–\mathrm{Sr}{\mathrm{F}}_2–\mathrm{Yb}{\mathrm{F}}_3$ fluoride ceramics of high optical quality was prepared, and its absorption, fluorescence, and laser oscillation properties were investigated. Oscillation slope efficiency that was only a few percent lower than that for a single crystal of similar composition was demonstrated under diode pumping.

We present the excitation power and doping concentration dependent upconversion properties of SrF₂:Yb³⁺,Er³⁺ single crystals. The determined optical properties of this bulk material can serve as benchmark values for cubic-phase nanomaterials.

Herein, we report near-infrared-to-visible up-conversion (UC) in SrF ₂ :Yb ³⁺ ,Er ³⁺ sub-micron crystals prepared via a facile route in an aqueous solution.