  We demonstrate a monolayer graphene based passively Q-switched fiber laser
with three-stage amplifiers that can deliver over 80 W average power at 1064
nm. The highest average power achieved is 84.1 W, with pulse energy of 1.67 mJ.
To the best of our knowledge, this is the first time for a high power passively
Q-switched fiber laser in the 1 um range reported so far. More importantly, the
Q-switched fiber laser operates stably during a week few-hours-per-a-day tests,
which proves the stability and practical application value of graphene in high
power pulsed fiber lasers.
