Spectral, luminescent, and lasing properties of ZrO2—Y2O3—Tm2O3 crystals

The absorption spectra corresponding to the transitions from the ground ³H₆ state to the excited multiplets ¹G₄, ³F₂, ³F₃, ³H₄, ³H₅, ³F₄, as well as the luminescence spectrum of the ³F₄ → ³H₆ laser transition of Tm³⁺ ions excited to the ³H₄ level in ZrO₂ — 12 mol % Y₂O₃ — 2 mol % Tm₂O₃ crystals are studied at a temperature of 300 K. The cross-relaxation (³H₄ → ³F₄, ³H₆ → ³F₄) efficiency of Tm³⁺ ions estimated by the integral characteristics of decay curves of luminescence from the ³H₄ level exceeds 90 %. The spectral dependences of the gain cross section of the ³F₄ → ³H₆ laser transition of Tm³⁺ ions are calculated for different relative population inversions. Lasing at the ³F₄ → ³H₆ transition of Tm³⁺ ions in diode-pumped ZrO₂ — 12 mol % Y₂O₃ — 2 mol % Tm₂O₃ crystals is obtained for the first time. The lasing wavelength is 2046 nm.