Quantitative characterization on multichannel transition emissions originating from 3P0 and 1D2 levels of Pr3+ in fluorotellurite glasses

Multichannel transition emissions in Pr3+-doped fluorotellurite (4BaF2?4AlF3?16BaO?6La2O3?70TeO2, BABLT) glasses have been quantitatively characterized. Broadband ?1.48??m near-infrared (NIR) emission due to 1D2???1G4 transition covering a 1.28?1.68??m wavelength region possesses a full-width at half-maximum of 120?nm, along with the spontaneous emission probability (Aij) and maximum stimulated emission cross-section (?em) are calculated to be 693?s?1 and 8.97???10?21?cm2, respectively. Intense visible fluorescence originating from 3P0 and 1D2 levels has been observed and the radiant flux for the visible fluorescence of Pr3+ is solved to be 299??W under commercial blue LED excitation. Quantitative characterization reveals that Pr3+-doped BABLT glasses exhibit a quantum yield (QY) as high as 14.9%, which is 3.1% higher than that in Pr3+-doped heavy metal germanium tellurite glasses. High QY and broadband ?1.48??m emission illustrate great advantages of Pr3+-doped BABLT glasses as fibre luminescence sources in photodynamic therapy treatment and gain media for tunable lasers and NIR optical amplifiers.