Abstract
Fluorescence transitions in LiNdP4O12: 4 F3/2→4I9/2 (0·90μm), 4F3/2→4I11/2 (1·05μm), 4F3/2→4I13/2 (1·32μm), 4F3/2→4I15/2 (1·77μm), and in LiErYP4O12: 4S3/2→4I11/2 (1·3μm), 4I13/2→4I15/2 (1·53μm), have been obtained at room temperature. The positions of the energy levels related to the excitation, nonradiative and radiative processes have been established from complementary absorption measurements. The fluorescence lifetimes of the above-mentioned transitions have been determined from single exponential decays.