Spectroscopic properties of heavily Ho3+-doped barium yttrium fluoride crystals**Project supported by the National Natural Science Foundation of China (Grant No. 61275146), the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20120002110066), and the Special Program of the Co-construction with Beijing Municipal Government of China (Grant No. 20121000302).

Abstract

The 30 at.% Ho: BaY2F8 crystals were grown by the Czochralski method, and their spectroscopic properties are analyzed systematically by standard Judd–Ofelt theory. The Judd–Ofelt intensity parameters are estimated to be Ω2 = 6.74 × 10−20 cm2, Ω4 = 1.20 × 10−20 cm2, and Ω6 = 0.66 × 10−20 cm2, and the fluorescence branching ratios and radiative lifetimes for a series of excited state manifolds are also determined. The emission cross sections with our measured infrared luminescence spectra, especially important for 4.1 μm, are calculated to be about 4.37 × 10−21 cm2. The crystal quality is preliminarily tested through a mid-infrared laser emission experiment.