Spectroscopic properties and energy transfer in Ga2O3– Bi2O3–PbO–GeO2 glasses codoped with Tm3+ and Ho3+

Abstract This paper reports on the spectroscopic properties and energy transfer in Ga 2 O 3 –Bi 2 O 3 –PbO–GeO 2 glasses doped with Tm 3+ and/or Ho 3+ . From the optical absorption spectra of Tm 3+ , Judd–Ofelt intensity parameters, radiative transitions probabilities, fluorescence branching ratios, and radiative lifetimes have been calculated using Judd–Ofelt theory. The measured differential scanning calorimetry result shows that the glass exhibits excellent stability against devitrification with Δ T = 129 °C. The measured luminescence spectra show that the 3 H 4 → 3 F 4 transition of Tm 3+ upon 808 nm laser diode excitation possess a broad full width at half-maximum of ∼126 nm. The maximum value calculated stimulated emission cross-section and the measured lifetime of 3 H 4 level from the 1.47-μm transition are ∼4.73 × 10 −21 cm 2 and ∼0.239 ms, respectively. It is noticed that codoping of Ho 3+ could significantly enhanced the ratio of the intensity of 1.47–1.80 μm by energy transfer via Tm 3+ : 3 F 4 → Ho 3+ : 5 I 7 .