Judd-Ofelt analysis of Ho3+ doped in ceramic CaSc2O4

A Judd-Ofelt analysis was performed on a calcium scandate (CaSc2O4) ceramic sample doped with 2 at% Ho3+. Using the measured lifetime of 5I7 level to calibrate the absorption spectrum, the Judd-Ofelt parameters were obtained: Ω2 = 3.78×10−20 cm2, Ω4 = 5.17×10−20 cm2, and Ω6 = 1.92×10−20 cm2. The electric-dipole and magnetic-dipole transition probabilities, radiative lifetimes and luminescence branching ratios were calculated. The quantum efficiency of the green emitting levels (5F4, 5S2) was found: 54%. The calibration method also allowed the estimation of the 'effective' thickness of the ceramic sample: approximately eight times greater than the geometric thickness.