CLEO®/Europe — IQEC 2013: NIR to visible upconversion in double-clad optical fiber co-doped with Yb3+/Ho3+

Summary form only given. In the paper the spectroscopic properties of antimony-silicate-germanate glass and optical fiber co-doped with Yb³⁺/Ho³⁺ has been investigated. Upconversion luminescence at the wavelengths of 547 nm (⁵S2 (⁵F₄) → ⁵I₈) and 659 nm (⁵F₅ → ⁵I₈) in holmium ion was obtained as a result of phonon assisted energy transfer between Yb³⁺ and Ho³⁺ ions . Elaborated glass characterized by highest intensity of upconversion luminescence (1mol% Yb₂O₃/0.5mol% Ho₂O₃) was used as core of double-clad, off-set core optical fiber. In conventional double-clad optical fibers, only the meridional rays can be absorbed in inner cladding. Offset the core from the center of the inner cladding enables to improve efficiency of optical pumping of the double-clad optical fiber. Basic parameters of the manufactured optical fiber were as follows: outer cladding diameter=400 μm, core diameter=15μm, NA_cladding=0.58, NA_core=0.4.