A large-mode-area（LMA） ytterbium-doped photonic crystal fiber（PCF） with core NA of 0.034 and core diameter of 50 μm was made by the stack-and-draw technique. The core is formed by Yb3+/Al3+/F-/P5+ co-doped silica...A large-mode-area（LMA） ytterbium-doped photonic crystal fiber（PCF） with core NA of 0.034 and core diameter of 50 μm was made by the stack-and-draw technique. The core is formed by Yb3+/Al3+/F-/P5+ co-doped silica glass containing 0.09 mol% Yb2O3 with an absorption coefficient at 976 nm up to 3.2 d B/m. The core glass with homogeneous distribution of Yb3+ ions and refractive index difference of 4 × 10-4 compared with pure silica was prepared by the sol-gel method and heat homogenization at 2000°C. Laser power amplification of this LMA PCF was studied using a seed source of 21 ps pulse duration and 48.7 MHz repetition rate at 1030 nm wavelength. With pump power of 520 W, a maximum 272 W（266 k W peak power） quasi-single-mode laser output with M2 of 2.2 was achieved in a 4.7 m fiber length bent at a diameter of 47 cm with slope efficiency of 52%, and no obvious mode instability, stimulated Raman scattering, or thermal damage on the end facet of the fiber were observed.展开更多
基金financially supported by the National High Technology Research and Development Program of China(No.2016YFB0402201)
文摘A large-mode-area（LMA） ytterbium-doped photonic crystal fiber（PCF） with core NA of 0.034 and core diameter of 50 μm was made by the stack-and-draw technique. The core is formed by Yb3+/Al3+/F-/P5+ co-doped silica glass containing 0.09 mol% Yb2O3 with an absorption coefficient at 976 nm up to 3.2 d B/m. The core glass with homogeneous distribution of Yb3+ ions and refractive index difference of 4 × 10-4 compared with pure silica was prepared by the sol-gel method and heat homogenization at 2000°C. Laser power amplification of this LMA PCF was studied using a seed source of 21 ps pulse duration and 48.7 MHz repetition rate at 1030 nm wavelength. With pump power of 520 W, a maximum 272 W（266 k W peak power） quasi-single-mode laser output with M2 of 2.2 was achieved in a 4.7 m fiber length bent at a diameter of 47 cm with slope efficiency of 52%, and no obvious mode instability, stimulated Raman scattering, or thermal damage on the end facet of the fiber were observed.
