Enhanced fluorescence and gain characteristics of PbS doped silica fiber with PbSe nano-semiconductor co-doping

•The local structure models of PbS/PbSe co-doped fiber materials are built based on density functional theory.•PbS/PbSe nano-semiconductor co-doped silica fiber exhibites broadband luminescence enhancement at 1000–1380 nm and achieved a net gain of 14.5 dB at 1160 nm.•PbSe co-doping improves the deposition environment of PbS and increases the density distribution of nanoparticles.