Crystal growth and properties characterization of Nd3+:Na5Lu(MoO4)4 for continuous multi-wavelength NIR laser emission

A new Nd3+ ions-doped NIR laser crystal of Na5Lu(MoO4)4 was grown in a 4Na2O–5MoO3 flux through the top-seeded solution growth (TSSG) technique. Thermal analysis indicated that Na5Lu(MoO4)4 melted incongruently and decomposed at 690 °C into NaLu(MoO4)2 and Na2MoO4. The photoluminescence measurements for different Nd3+ dopant concentrations showed that Na5Lu(MoO4)4 can achieve high activator doping, and the saturation concentration for Nd3+ ions can reach 10% without an obvious quenching effect. In addition, the optical absorption spectra for the 1.48% Nd3+:Na5Lu(MoO4)4 single crystal were measured, from which the absorption parameters of Ω2 = 5.288 × 10−20 cm2, Ω4 = 3.802 × 10−20 cm2, and Ω6 = 5.206 × 10−20 cm2 were calculated by the Judd–Ofelt theory. Furthermore, a continuous multi-wavelength NIR laser emission with a 60 mW laser power around 1059 nm and 1065 nm multi-bands and slope efficiency of 6.2% output was achieved in the Nd3+:Na5Lu(MoO4)4 crystal for the first time, showing promising applications as a new kind of laser diode (LD) pumped ultrashort pulse solid-state laser.