Growth, structure and spectral properties of Yb3+-doped KY(WO4)2 laser crystal

Yb3+-doped KY(WO4)2 (Yb:KYW) laser crystal was grown by top seeded solution growth (TSSG) method. The solute and solvent calcined at 920℃ and 600℃ respectively for 8h formed a single phase as shown by XRD analysis, which suppressed the volatilization in the growth process. The as-grown crystal was identified as β-Yb:KYW by XRD, and the cell parameters of Yb:KYW were calculated to be a=1.063nm, b=1.034nm, c=0.755nm and β=130.75°. Absorption spectrum of samples with different thickness (E//c) were obtained, in which two intensive peaks at 933nm and 981nm were observed, and the absorption cross section is 5.34×10-20cm2 at the main peak of 981nm. Fluorescence spectrum of the sample was measured and there exist three intensive emission peaks at 990, 1010 and 1030nm. It was calculated that the peak emission cross section is 3.1×10-20cm2 at 1030nm and the lifetime is 0.56ms which is closed to the measured value. The pumping parameter (β), saturated pump intensity (Isat) and minimum pump intensity (Imin) were calculated, and the parameter Imin (24kW/cm2) of Yb:KYW is very low compared to other Yb3+ doped crystals.