Phosphor for the near-IR and short-wave IR ranges based on a garnet structured cubic modification of lithium–lanthanum niobate

Cubic garnets activated by neodymium and holmium, Li$_{6}$CaLa$_{2}$Nb$_{2}$O$_{12}$ : Nd$^{3+}$, Ho$^{3+}$, were obtained by solid-state method. The main regularities of changes in the luminescence properties of Li$_{6}$CaLa$_{2}$Nb$_{2}$O$_{12}$ : Nd$^{3+}$, Ho$^{3+}$ solid solutions in the visible, near-IR, and short-wave IR ranges under 808 nm laser diode radiation are determined. The energy transfer mechanism between active centers, involving the participation of Nd$^{3+}$ ions as sensitizers for the luminescence of Ho$^{3+}$ ions, is proposed. Low phonon energy, high luminescence intensity in the range of 2.0–3.0 $\mu$m, and weak up-conversion luminescence in the region of 450–780 nm make it possible to consider the cubic lithium–lanthanum niobates Li$_{6}$CaLa$_{2}$Nb$_{2}$O$_{12}$ : Nd$^{3+}$, Ho$^{3+}$ as promising phosphors of the short-wave IR range.