Investigation of mid-infrared emission characteristics and energy transfer dynamics in Er(3+) doped oxyfluoride tellurite glass

Er(3+) doped oxyfluoride tellurite glasses have been prepared. Three Judd-Ofelt parameters Ω(t) (t = 2, 4, 6) and radiative properties are calculated for prepared glasses. Emission characteristics are analyzed and it is found that prepared glasses possess larger calculated predicted spontaneous transition probability (39.97 s(−1)), emission cross section σ(em) (10.18 × 10(−21) cm(2)) and σ(em) × Δλ(eff) (945.32 × 10(−28) cm(3)), corresponding to the 2.7 μm emission of Er(3+): (4)I(11/2)→ (4)I(13/2) transition. The results suggest that the prepared glasses might be appropriate optical material for mid-infrared laser application. Moreover, rate equation analysis which is rarely used in bulk glass has been carried out to explain the relationship between emission intensity and Er(3+) concentration. The calculation results show that with the increment of Er(3+) concentration, the energy transfer up-conversion rate of (4)I(13/2) state increases while the rate of (4)I(11/2) state reduces, resulting in the change of 2.7 μm emission.