Role of PbO substitution by Bi2O3 on 1.47 μm luminescence properties of Tm3+/Tb3+-doped Bi2O3–GeO2–Ga2O3 glass

Spectroscopic properties and energy transfer (ET) in Bi2O3(PbO)–GeO2–Ga2O3 (BPGG) glass doped with Tm3+ and/or Tb3+ have been investigated. It is noted that the Tm3+ single-doped BPGG glass exhibits broad 1.47-μm fluorescence peaked at 1465 nm with a full width at half-maximum (FWHM) of ∼134 nm. The incorporation of Tb3+ into Tm3+-doped BPGG glass could significantly decrease the 1.80 μm emission intensity and enhance the intensity ratio of 1.47-μm to 1.80-μm (I1.47/I1.80), which reveals that Tb3+ ion can be considered to be an effective sensitizer ion on improving the 1.47-μm emission. The products of FWHM×σepeak and τf×σepeak for the 1.47-μm fluorescence are in the range of 5.66–6.63 × 10−26 cm3 and 8.76–10.02 × 10−25 cm2 s. Effects of Bi2O3 substitution for PbO on spectroscopic properties, such as 1.47-μm emission of Tm3+, Judd–Ofelt intensity parameters Ωt (t = 2, 4, 6), and the lifetime of the 3H4 level of Tm3+, have also been investigated.