Ho 3+ doped germanate-tellurite glass sensitized by Er 3+ and Yb 3+ for efficient 2.0 μm laser material

Abstract 2.0 μm spectroscopic properties of Ho 3+ /Er 3+ /Yb 3+ tri-doped germanate-tellurite (GT) glasses pumped by 980 nm LD and the energy transfer mechanisms between the three rare earth ions were investigated based on near-infrared and mid-infrared fluorescence spectra. According to the measured absorption spectra, the Judd-Ofelt parameters were calculated and discussed. Mid-infrared transmittance property of glass was investigated by Fourier transform infrared (FTIR) spectrometer. The 2.0 μm radiative transition probability and emission cross section are 69.33 s −1 and 5.77 × 10 −21 cm 2 , respectively, and superior gain performance was also obtained from the prepared glass. Meanwhile, the maximum 2 μm emission lifetime of Ho 3+ /Er 3+ /Yb 3+ tri-doped glass can reach as high as 6.83 ms. In addition, energy transfer microscopic parameters (C DA ) were calculated to evaluate 2 μm fluorescence. Hence, all results reveal that Ho 3+ /Er 3+ /Yb 3+ tri-doped germanate-tellurite glass is a promising material for improving the Ho 3+ 2.0 μm fiber laser performance.