Fabrication and laser behaviors of Yb3+ doped silica large mode area photonic crystal fiber prepared by sol-gel method

Yb3+, Al3+ co-doped silica large mode area photonic crystal fiber (LMA CF) has been prepared by sol-gel method combined with stack-capillary-draw technique. The core glass with composition of 0.3Yb(2)O(3)-3Al(2)O(3)-96.7SiO(2) (mol%) has 927 mu s fluorescence lifetime, 0.82 pm(2) stimulated emission cross section at similar to 1 mu m and 1.4 ppm residual hydroxyl group. 6.8 W continuous-wave fiber laser ranging from 1040 to 1070 nm has been obtained from a piece of 98-cm-long PCF with the Yb3+ concentration of 6.49 x 10(19) ions/cm(3) pumped by a commercial 927-nm laser diode. The laser has a threshold of 1.45 W launched power with a slope efficiency of 48%. The maximum output power of 6.8W is limited by the available pumping power, and the optical loss is 1.2 dB/m at 1053 nm. To the best of our knowledge, this is the highest laser output power report on Yb3+, Al3+ co-doped silica LMA PCF prepared by sol-gel method. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.