Spectroscopic investigation of Er3+ doped BaF2 single crystal

We report on the spectroscopic investigation of Er3+ doped BaF2 single crystals. High-quality crystals have been gown by the Bridgman-Stockbarger pulling technique. The room temperature absorption, excitation, emission and fluorescence decay spectra of the luminescent Er3+ ions inserted in BaF2 fluoride single crystals have been investigated. Using the Judd-Ofelt (JO) theory, the intensity parameters of Er3+ ions have been calculated to be Ω2 = 0.949 × 10−20 cm2, Ω4 = 0.975 × 10−20 cm2 and Ω6 = 1.258 × 10−20 cm2. These parameters were then used to calculate the radiative transition probabilities (AJJ′), branching ratios (βJJ′) and radiative lifetimes (τrad) of the main laser emitting levels of Er3+ ions. The obtained spectroscopic properties are compared to those of Er3+ transitions in other fluoride and oxide hosts. The excitation spectrum in the UV-Visible spectral range is very close to the absorption spectrum indicating that all observed absorption levels can excite the Erbium green emission. The emission spectrum is mainly dominated by the green emission alongside a weak red emission. For the main transitions, there is a good agreement between the emission spectrum and the spontaneous emission probabilities given by the JO analysis. Using the Fuchtbauer-Ladenburg method, the emission cross-section of the three main visible emission were determined in addition to other important laser parameters such radiative quantum efficiency and optical gain.