Physicochemical, spectral, luminescence, and stimulated emission properties of phosphate glasses with high neodymium concentrations

Phosphate glasses of the R–Nd (R≡Li, Na, K, Rb, Cs) and Li–Nd–La types were synthesized and investigated. The number of the Nd³⁺ ions in the Li–Nd_1.0 glass was found to be 2.7×10²¹ cm^–3, the luminescence decay constant was 80 μsec, the absolute quantum efficiency was 0.23, and the cross section of the stimulated transition was 3.8×10^–20. Stimulated emission from a sample of Li–Nd_1.0 was obtained when the threshold pump energy was 5 mJ. Spectroscopic measurements indicated that such glasses could be used in microlasers pumped with semiconductor light-emitting diodes.