Transition intensities and excited state relaxation dynamics of Tm3+ in Tm:PbF2 crystal

High-quality Tm doped β-PbF₂ crystal is grown by the Bridgman method in a nonvacuum atmosphere. Optical absorption spectra were acquired and analysed in the framework of the Judd-Ofelt theory. Values of radiative transition rates and luminescence branching ratios calculated using phenomenological intensity parameters Ω_λ were compared to corresponding experimental values derived from measurement of luminescence spectra and decay curves. The emission cross-sections of the ³ F ₄ → ³ H ₆ transitions of the Tm³⁺ ions at 1.86 μm wavelengths were estimated by the use of the Fuchtbauer-Ladengurg method.