Study on visible luminescence of the Tm3 +: 1D2 → 3 F4 emission state in lead borate titanate aluminumfluoride glasses

This paper reports the visible luminescence properties of 1D2 state of Tm3 + -doped lead borate titanate aluminumfluoride (LBTAFTm) glasses. The absorption and luminescence was analyzed within the frame work of Judd-Ofelt model. The reliability of J-O intensity parameters obtained from the experimental oscillator strengths have satisfactorily been correlated with the calculated oscillator strengths with small r.m.s deviation of ± 0.12 × 10-6 by the least square fit analysis. Upon 359 nm excitation, the luminescence spectra show only one emission band at 458 nm (blue) corresponding to the 1D2 → 3 F4 transition in the spectral region 400–500 nm. No luminescence quenching has been observed with the increase of Tm3 + concentration. The decay profiles of the 1D2 level have shown single-exponential nature for all the concentrations and the decay times were found to decrease with the increase of concentration. The stimulated emission cross-section (σe) for the observed emission transition has also been computed. The large quantum efficiency (η) of the 1D2 level suggests the utility of LBTAFTm glass as a potential host for optical device applications at 458 nm emission wavelength.