Blue and near-infrared up-conversion in double-air-cladding Tm3+-doped silica fiber under 1064 nm excitation

Double-air-cladding Tm3+-doped silica fiber with a large core is fabricated by stacking capillaries method. By the excitation at 1064 nm, the optical properties of this fiber doped with 0.1 mol% Tm3+ are studied. The blue and near-infrared emissions around 473 and 793 nm are experimentally observed. In addition, the up-conversion mechanism of Tm3+ in glass is investigated. The results show that the Tm3+-doped fiber with a large core can be used as the potential optical material for the high power fiber laser which operates at the blue and near-infrared wavelengths.