Intensity analysis and crystal-field modeling of HO~(3+) in KPb_2CI_5 host

摘要

Optical absorption and emission intensities are investigated for HO~(3+) doped into single-crystal KPb_2Cl_5. Room temperature absorption spectra of HO~(3+)(4f~(10)), representing transitions from ~5I_8 to excited multiplet manifolds observed between 400 and 2100 nm, have been analyzed using the Judd-Ofelt (JO) model to obtain the phenomenological intensity parameters Ω_2, Ω_4, and Ω_6. The JO intensity parameters are used to calculate the spontaneous emission probabilities, radiative lifetimes, and branching ratios of the HO~(3+) transitions from the upper multiplet manifolds to the corresponding lower-lying multiplet manifolds ~(2S+1)L_J of HO~(3+). The room temperature fluorescence spectrum in the near infrared region is reported between 850 and 1550 nm. The emission cross section for the intermanifold transition, ~5F_5→~5I_7 (0.98 μm) has been determined. The 8 K absorption spectrum was examined as well. The detailed structure observed in the absorption bands ~5I_7,~5S_2,~5F_4, and ~5F_3, was analyzed in terms of the crystal-field splitting of each manifold using a charge-compensation model first developed for Er~(3+) doped into KPb_2Cl_5. The optical and spectroscopic characteristics of HO~(3+):KPb_2Cl_5 demonstrate that this material has potential as a laser host system at various wavelengths.