Gamma irradiation-induced enhancement of Pb-related near-infrared luminescence in PbS/Al co-doped silica fiber

Abstract

The impact of Al co-doping and gamma irradiation (0.3-3 kGy) on the spectral properties of lead-related active centers (PACs) in PbS/Al co-doped silica fiber (PADF) has been studied. Distinct absorption peaks at 700 and 1030 nm, and photoluminescence at 1100 nm, originated from Al-related lead active center (PAC-Al). The luminescence intensity of PACs at 900 and 1150 nm increased with irradiation doses in PADF with 0.01 at% Al co-doping. Notably, after irradiation with a 0.5 kGy dose, over a 16 dB enhancement of luminescence from PAC-Al was observed in PADF doped with 0.1 at% Al under 980 nm pumping. The on-off gain of the PADF at 1100 nm increased ∼12 dB after irradiation with a dose of 0.3 kGy. It was found that PAC-Al was preferentially generated over PAC at 1150 nm in Al co-doped fibers under irradiation. The proposed underlying mechanism for photoluminescence enhancement is the irradiation-induced reduction of Pb ions and Al-related defects. PbS/Al co-doped silica fiber is a promising candidate for active fibers operating at ∼1100 nm.