Study of air-clad large-mode-area ytterbium doped photonic crystal fiber

The Yb3+ doped double clad photonic crystal fiber (PCF) with a large core of around 90 mu m in diameter is prepared from SiO2-Al2O3-P2O5 core glass of an optical fiber preform through a conventional modified chemical-vapor deposition technique, solution doping and gas doping. The double clad PCF has a mode area of about 1330 mu m(2). The core and inner cladding have numerical apertures of about 0.065 and 0.5, respectively. 1 m long photonic crystal fiber laser generates up to 102 W output power with a slope efficiency of 76%. Such lasers are potentially scalable to high power.