Thermal-induced luminescence enhancement of BAC-P in bismuth-doped phosphogermanosilicate fibers

The thermal quenching effect has been systematically investigated in bismuth (Bi)-doped phosphogermanosilicate fiber with varying thermal conditions. For the first time, to the best of our knowledge, the activation of phosphorrelated Bi active center (BAC-P) is achieved by thermal quenching at 400°C with a heating time of 10 min, evidenced by the enhanced luminescence of BAC-P (∼1.3 times) at 1300 nm. The experimental results reveal that a relatively low heating temperature with prolonged heating time stimulates the growth of BAC-P, whereas higher operating temperatures (≥500°C) result in the irreversible destruction of BAC-P. The underlying mechanism for the thermally stimulated BAC-P process is also analyzed and discussed.