Energy transfer between Bi³⁺ and Nd³⁺ in germanate glass

Energy transfer from Bi³⁺ to Nd³⁺ is reported in germanate glass. It was found that the excitation range and intensities of the ⁴F _{3 2} → ⁴I _{9 2}, ⁴I _{11 2} emissions are increased several fold when excited through ¹S₀ → ³P₁ absorption of Bi³⁺. It is shown that the energy transfer is nonradiative. The energy transfer probability and efficiency were calculated from the Bi³⁺ fluorescence decay rates and intensities. The Bi³⁺ → Nd³⁺ energy transfer may be utilized in Nd³⁺ glass laser.