Shangqian Sun

Characterization of Disordered Melilite

A disordered Nd:SrLaGa₃O₇ (Nd:SLGM) laser crystal was grown by the Czochralski method. The thermal properties, including the average linear thermal expansion coefficient, thermal diffusivity, specific heat, and thermal conductivity were measured. Thermal conductivity values along the - and -axes were found to be 1.95 and 1.70 W m^-1 K^-1, respectively, near 30°C, neither of which are as high as the previously reported value of 11 W m^-1 K^-1. It was found that the thermal conductivity increases with increasing temperature, which is similar to the behavior of glass. The polarized absorption and emission spectra were measured at room temperature, and Judd-Ofelt analysis was carried out to calculate the fluorescence branching ratios and the fluorescence lifetime. The stimulated emission cross-section for the ⁴F_3/2 → ⁴I_11/2 transition was calculated to be 1.0×10^-19 cm². Finally, a diode-pumped laser experiment at 1.06 μm was performed. The highest peak power achieved was 1.16 W with an optical slope efficiency of 11%. The results indicate that Nd:SLGM is a promising material for use as disordered laser medium.