Effect of B2O3 addition on luminescent properties and energy transfer in Er3+/Ho3+-codoped tellurite glasses

The B2O3 oxide in different concentration was introduced into Er3+/Ho3+ codoped tellurite glass with conventional composition TeO2ZnONa2O to investigate its effect on the near-infrared band luminescence of doped rare-earth ions under the excitation of 980 nm LD. The UV/Vis/NIR absorption spectrum, Vis/NIR fluorescence emission spectrum, fluorescence decay curve, DSC curve and Raman spectrum of the prepared glass samples were measured and investigated. With the introduction of B2O3 in a certain concentration range, the 1.55 μm band fluorescence of Er3+ improved greatly, whereas the 2.03 μm band one of Ho3+ decreased first and then increased slightly. The Judd-Ofelt intensity parameter, radiative transition probability, quantum efficiency, multi-phonon relaxation rate and energy transfer micro-parameter were calculated to explain the obtained experimental results. The present works indicate that the enhanced multi-phonon relaxation of excited state ions and energy transfer between Er3+ and Ho3+ ions due to the increased phonon energy of glass host with the introduction of B2O3 are responsible for the observed luminescent phenomena, and Er3+/Ho3+ codoped tellurite glass with an appropriate amount of high phonon energy B2O3 is a promising candidate applied for the near-infrared band solid-state lasers and fiber amplifiers.