Growth, nonlinear frequency-doubling and spectral properties of Nd:Ca8.53K1.09La0.95(VO4)7 crystal

The 18.7 at% Nd:Ca8.53K1.09La0.95(VO4)7 crystal with dimensions up to ∅ 22 mm×30 mm was grown by the Czochralski method. The X-ray powder diffraction pattern of Nd:Ca8.53K1.09La0.95(VO4)7 crystal confirms that the as-grown crystal is isostructural with pure Ca9La(VO4)7 crystal. The effective segregation coefficients of Nd3+ and K+ ions in the crystal were measured to be about 1.21 and 0.73, respectively. The hardness of Nd:Ca8.53K1.09La0.95(VO4)7 crystal is about 358.3 VDH. The qualitative frequency-doubling experiment shows that the doping of K+ ion can help reduce the scattering of frequency-doubling light. The spectroscopic study of Nd3+ in Nd:Ca8.53K1.09La0.95(VO4)7 crystal was performed, and the polarized absorption and fluorescence spectra were analyzed based on Judd–Ofelt theory, which exhibits that the π-polarized absorption and stimulated emission cross sections are 4.41×10−20 cm2 with an FWHM 11 nm at 810 nm and 1.61×10−19 cm2 at 1066 nm, respectively. The fluorescence lifetime is 128 μs at room temperature. All the results indicate that the Nd:Ca8.53K1.09La0.95(VO4)7 crystal may be a highly efficient laser material and thus a promising candidate of self-frequency-doubling laser material.