Pr3+-doped heavy metal germanium tellurite glasses for irradiative light source in minimally invasive photodynamic therapy surgery

Pr3+-doped medium-low phonon energy heavy metal germanium tellurite (NZPGT) glasses have been fabricated and the intense multi-peak red fluorescence emissions of Pr3+ are exhibited. Judd-Ofelt parameters ω2 = 3.14 × 10?20cm2, ω4 = 10.67 × 10?20cm2 and ω6 = 3.95 × 10?20cm2 indicate a high asymmetrical and covalent environment in the optical glasses. The spontaneous emission probabilities Aij corresponding to the 1D2→3H4, 3P0→3H6, and 3P0→3F2 transitions are derived to be 1859.6, 6270.1 and 17276.3s?1, respectively, and the relevant stimulated emission cross-sections ?em are 5.20 10?21, 14.14 × 10?21 and 126.77 × 10?21cm2, confirming that the effectiveness of the red luminescence in Pr3+-doped NZPGT glasses. Under the commercial blue LED excitation, the radiant flux and the quantum yield for the red fluorescence of Pr3+ are solved to be 219?W and 11.80%, respectively. 85.24% photons of the fluorescence in the visible region are demonstrated to be located in 600?720nm wavelength range, which matches the excitation band of the most photosensitizers (PS), holding great promise for photodynamic therapy (PDT) treatment and clinical trials.