Judd-Ofelt analysis of spectroscopic properties of Tm³⁺, Ho³⁺ doped GdVO₄ crystals

Tm³⁺: GdVO₄ and Ho³⁺: GdVO₄ crystals with good optical quality were grown by Czochralski technique. Polarized absorption and unpolarized fluorescence spectra of Tm³⁺ and Ho³⁺ in GdVO₄ crystals were measured. The Judd-Ofelt (JO) model was applied to obtain the three phenomenological intensity parameters. For Tm³⁺, Ω₂ = 8.16 × 10^-20, Ω₄ = 2.45 × 10^-20, Ω₆ = 0.98 × 10^-20 (with dimension of cm²). For Ho³⁺Ω₂ = 1.51 × 10^-20, Ω₄ = 1.61 × 10^-20, Ω₆ = 1.22 × 10^-20 (with dimension of cm²). The radiative probabilities, radiative lifetimes, and branch ratios of Tm³⁺ and Ho³⁺ in GdVO₄ crystals were then determined. Using the reciprocity method and Fuchtbauer-Ladenberg formula, the stimulated emission cross-sections for some interested transitions, such as (⁵F₄, ⁵S₂) → ⁵I₈ of Ho³⁺ and ¹G₄ → ³H₆, ³H₄ → ³F₄ of Tm³⁺ in GdVO₄, were determined and discussed.