Fabrication, spectroscopic characteristics, and lasing performance of Nd,La:CaF₂ transparent ceramics

In this study, Nd,La:CaF 2 transparent ceramics were fabricated from powders synthesized in the liquid phase. The light scattering in the ceramics was significantly reduced because of the homogeneous doping of Nd 3+ and La 3+ ions, realizing the laser-grade transparency. To suppress the fluorescence quenching of Nd caused by [Nd 3+ –Nd 3+ ] clustering, the required concentration of La 3+ was approximately eight times that of Nd 3+ . The experimentally measured optical properties of the fabricated ceramics, including the emission cross-section, fluorescence lifetime, and branching ratios, were closely aligned with predictions from a Judd-Ofelt analysis. These well-characterized Nd,La:CaF 2 transparent ceramics were evaluated with respect to their laser performance, showing a maximum slope efficiency of 20%. To the best of our knowledge, this efficiency was remarkably superior to previously reported results. Nd,La:CaF 2 transparent ceramics are among the most promising materials for next-generation high-power ultrashort-pulse lasers operable with LD pumping at room temperature.