Effect of lead oxide on optical properties of Dy3+ ions in PbO–H3BO3–TiO2–AlF3 glasses

The effect of lead oxide (PbO) on optical properties of Dy3+-doped PbO–H3BO3–TiO2–AlF3 (LBTAFDy) glasses is investigated. The LBTAFDy glasses were prepared with different PbO contents ranging from 30 to 60 mol%. The Judd–Ofelt intensity parameters (Ωλ = 2, 4, 6) are obtained by the least square fit analysis. It is found that the Ω2 parameter and yellow-to-blue intensity ratio (Y/B) of the Dy3+ emission depend on the PbO content in LBTAFDy glass. The structural asymmetry around the Dy3+ ion and the DyO covalency are responsible for the changes in Ω2 parameter and Y/B ratio. The variation of decay time of 4F9/2 emission level with the PbO content also supports the changes in structural asymmetry and DyO covalency in LBTAFDy glass.