Amplification at 2.3-µm in 1.9-µm thulium-doped silica fiber laserChangshun Hou, Debasis Pal, Colin C. Baker, Tony Zhou, Daniel Rhonehouse, Jasbinder Sanghera and Johan NilssonEPJ Web Conf., 307 (2024) 02045DOI: https://doi.org/10.1051/epjconf/202430702045