Examination of Judd-Ofelt calculation and temperature self-reading for Tm3+ and Tm3+/Yb3+ doped LiYF4 single crystals

To validate the reliability of Judd-Ofelt results and the influence of involving absorption transition number, the Judd-Ofelt calculations, in which various transitions were adopted, were carried out for Tm3+ doped LiYF4 single crystal. It was found that introducing more transitions into the calculation procedure might get more reliable results. In order to clarify the feasibility of temperature self-reading in Tm3+/Yb3+ doped LiYF4 single crystal during laser operation, the temperature sensing properties of the single crystal were studied. It was found that the fluorescence intensity ratio of F-3(2) + F-3(3) -> H-3(6) to H-3(4) -> H-3(6) can be used for achieving better temperature detection, and the temperature sensitivity was found much better than that in other materials.