Spectroscopic, thermal and laser characteristics of Nd:LiLuF4 for 1314 nm laser

Nd-doped LiLuF4 crystal was grown by the traditional Czochralski method. Room-temperature polarized spectroscopic characteristics of Nd3+ ions in LiLuF4 crystal were investigated. The maximum emission cross-sections are 5.45 × 10−20 cm2 at 1320 nm and 2.34 × 10−20 cm2 at 1313 nm for π-polarization and σ-polarization, respectively. The thermal expansion coefficient, specific heat, thermal diffusion coefficient and the thermal conductivity of Nd:LiLuF4 crystal were systematically studied, which, to the best of our knowledge, is the first time for this crystal thus far. Laser operation in an Nd:LiLuF4 single crystal at 1314 nm with laser-diode pumping was demonstrated. We obtained 3.7 W output power at 1314 nm with a slope efficiency of near 32%. The results of our study indicate that Nd:LiLuF4 crystal is a very promising crystal for application as a high-peak power laser.