255 W picosecond MOPA laser based on self-made Yb-doped very-large-mode-area photonic crystal fiber

We report on the amplification of high-average-power and high-efficiency picosecond pulses in a self-made verylarge-mode-area Yb-doped photonic crystal fiber (PCF).The PCF with a core diameter of 105 μm and a core numerical aperture of 0.05 is prepared by the sol-gel method combined with the powder sintering technique.The fiber amplification system produces the highest average power of 255 W at a 10 MHz repetition rate with a 21 ps pulse duration corresponding to a peak power of 1.2 MW.This result exemplifies the high-average-power and high-peak-power potential of this specifically designed fiber.