Spectroscopy of Pb/Bi co-doped silica optical fibers fabricated via atom layer deposition with modified chemical vapour deposition

Abstract We fabricated a novel Pb/Bi co-doped silica optical fiber using an atomic layer deposition technique in conjunction with a modified chemical vapour deposition process. The fabricated fiber exhibits distinct absorption peaks at 690, 800, 1000 and 1377 nm. An ultra-broad luminescence band with a 10 dB bandwidth of 600 nm from 1050 nm to 1650 nm was achieved using a dual pumps system. The lifetime of the co-doped fiber at 1150 nm is approximately 740 μs. Additionally, a Pb/Bi co-doped fiber with a length of only 0.2 m, pumped at 980 nm exhibits an optical gain ranging from 1010 to 1190 nm with a maximum peak gain of 12 dB. A theoretical model considering the interaction between Pb and Bi ions is proposed to interpret the observed spectral characteristics. There may be a coupling effect and/or energy transfer between Pb and Bi ions during a deleterious non-radiative quenching process. The Pb/Bi co-doped fiber offers a number of advantages compared to a conventional Bi-doped fiber in terms of broadband luminesce, fluorescence lifetime, and gain. Additionally, it can act as a super fluorescence fiber sources for optical amplifiers and novel fiber lasers in the medical and communication fields.