Spectroscopic and laser properties of Tm3+ ions in Ca3(VO4)2 crystal

The spectroscopic properties of Tm³⁺ ions in Ca₃(VO₄)₂ crystal were investigated and diode pumped tunable lasing was demonstrated. The maximum absorption and emission cross-sections for E⊥c at ³F₄-³H₆ 2 µm transition were calculated to be ~1 × 10^–20 cm² and ~1.3 × 10^–20 cm² respectively. Noticeable ³H₄-³F₄ ³H₆-³F₄ cross-relaxation was observed resulting in a slope laser efficiency up to 15% at ~1960 nm under 792 nm laser diode pumping. Broadband tuning of the oscillation wavelength within the 1850–2070 nm spectral range was realized.