Spectral analysis of thulium doped zinc-boro-silicate glass

This paper reports on the results concerning the optical absorption and photoluminescence spectra of Tm3+-doped zinc-boro-silicate (ZBS) glass. Absorption spectrum of this glass has revealed seven absorption bands in the wavelength region of 300–2000 nm. From the measured oscillator strengths of these absorption bands, three phenomenological Judd–Ofelt intensity (Ω2, Ω4, Ω6) parameters have been computed by the application of a least-squares fit analysis. These intensity characteristic factors have successfully been used in evaluating the radiative properties of the emission transitions of the rare earth ion (Tm3+) in zinc borosilicate glass. The measured emission profile of this Tm3+-glass, has displayed three emission bands such as 1D2→3H4 (weak blue), 1G4→3H6 (strong blue) and 1G4→3H4 (weak red), when excited by 356 nm wavelength. Lifetime (τm) of the blue emission (1G4→3H6) at 473 nm has been measured and compared with the radiative lifetime (τR) obtained based on the application of Judd–Ofelt theory. Non-radiative relaxation mechanisms have been attributed to the multiphonon-assisted relaxation on the basis of the high-energy phonon modes that could be found in the glass network.