Characterization of fluorescence lifetime of Tm-doped fibers with increased quantum conversion efficiency

In this work we report on the fluorescence lifetime characterization of the experimentally prepared Tm-doped silica optical fibers with increased quantum conversion efficiency (QE). Optical fibers were drawn from preforms prepared by conventional solution-doping of thulium and aluminium chlorides and by deposition of dispersed alumina nanoparticles with thulium chloride. Prepared preforms and optical fibers were characterized by means of thulium and aluminium concentrations, refractive index profiles, optical spectral attenuations (absorptions) and fluorescence lifetimes. Highly aluminium-codoped optical fiber prepared from alumina nanoparticles exhibited fluorescence lifetime of about 690 µs, which is about 40% higher compared to the conventionally prepared Tm-doped silica fiber