Evaluation of spectroscopic properties of Er3+/Yb3+ /Pr3+: SrGdGa3O7 crystal for use in mid-infrared lasers

Abstract

Er3+/Yb3+ /Pr3+: SrGdGa3O7 crystal was firstly grown by Czochralski method. Detailed spectroscopic analyses of Er3+/Yb3+ /Pr3+: SrGdGa3O7 were carried out. Besides better absorption characteristic, the spectra of Er3+/Yb3+ /Pr3+: SrGdGa3O7 show weaker up-conversion and near-infrared emissions as well as superior mid-infrared emission in comparison to Er3+: SrGdGa3O7 and Er3+/Yb3+ /Pr3+: SrGdGa3O7 crystals. Furthermore, the self-termination effect for Er3+ 2.7 1/4m laser is suppressed successfully because the fluorescence lifetime of the 4 I13/2 lower level of Er 3+ decreases markedly while that of the upper 4I11/2 level changes slightly in Er3+ /Yb 3+/Pr3+: SrGdGa3O7 crystal. The sensitization effect of Yb3+ and deactivation effect of Pr 3+ ions as well as the energy transfer mechanism in Er3+/Yb3+/Pr3+: SrGdGa3O7 crystal were also studied in this work. The introduction of Yb3+ and Pr 3+ is favorable for achieving an enhanced 2.7 μ4m emission in Er3+/Yb3+/Pr3+: SrGdGa3O7 crystal which can act as a promising candidate for mid-infrared lasers.