Abstract
In the visible range at blue 455 nm, 482 nm, and red 670 nm under upconversion pumping at a wavelength of 1064 nm, spectroscopic characteristics, and transition rates in Tm3+ doped 0.53 ZrF4, 0.2 BaF2, 0.04 LaF3, and 0.03 AlF3 and 0.2 NaF (ZBLAN) glass matrix are described. The Judd-Ofelt theory is applied to calculate the contributions from electric and magnetic dipoles to the optical intensity parameters (omega(t)), which are found to be as follows: omega(2) = 1.4703 +/- 0.0675, omega(4) = 0.7477 +/- 0.0536, omega(6) = 0.6202 +/- 0.0212. For transitions originating from the D-1(2), (1)G(4), F-2(2), F-3(3), and F-3(4) levels, branching ratios (beta), radiative lifetimes (tau (rad) in ms units), and transition probabilities (in s(-1)) have been calculated. Additionally, we evaluated the optical gain at 455 nm, 467 nm, and 670 nm, as well as the absorption/emission cross sections for the three visible transitions. According to the obtained results, the transition at 455 nm (D-1(2) -> F-3(4)) had the largest emission cross section values compared to transitions at 482 nm ((1)G(4) -> H-3(6)) and 670 nm (F-3(2) -> H-3(6)). Furthermore, the transition probability.is theoretically calculated for the ultraviolet (UV) range 172-283.8 nm. A good agreement is found between the calculations and the measurements for the visible range.