Host-dependent optical transitions of Er3+ ions in lead–germanate and lead-tellurium-germanate glasses

Abstract

Differential scanning calorimetry, Raman scattering, optical absorption, and upconversion of infrared to green luminescence have been studied for Er³⁺‐doped lead‐germanate glass 55GeO₂⋅20PbO⋅10BaO⋅10ZnO⋅5K₂O (GPBZK) and lead‐tellurium‐germanate glass 30GeO₂⋅30PbO⋅30TeO₂⋅10CaO (GPTC). Judd–Ofelt intensity parameters of Er³⁺ in the two host glasses were determined and used to calculate radiative transition rates and lifetimes. Values of the radiative quantum yield of the ⁴S_3/2→⁴I_15/2 transition and the infrared (797 nm) to green (547 nm) upconversion efficiency of Er³⁺ were obtained. It has been found that the ⁴S_3/2→⁴I_15/2 radiative transition rate of Er³⁺ in GPTC glass is about twice that in the GPBZK glass and the upconversion efficiency in the GPTC glass is about four times larger than that in the GPBZK glass. These host‐dependent properties are mainly attributed to the enhanced local field and the reduced multiphonon rate in lead‐tellurium‐germanate glass compared to lead‐germanate glass.