Thermal and optical properties of Tm3+: Li6Gd(BO3)3 crystal: A potential candidate for 1.83 μm lasers

Single crystal of Tm3+: Li6Gd (BO3)3 was grown by the Czochralski method. The heat capacity was measured from 308 to 673 K. The absorption spectra of the crystal in three mutually perpendicular arbitrary directions were measured at room temperature. Based on the Judd-Ofelt theory and the spectra measured in three mutually perpendicular directions, the intensity parameters Ωt (t=2, 4, 6), the line strengths, the oscillator strengths, the radiative rates, radiative lifetimes and fluorescent branching ratios were calculated. We calculated the emission cross-section by the reciprocity method and also obtained the gain cross-section.