500 nJ femtosecond fiber laser at 976 nm

Yb-doped fibers pumped at 976 nm will naturally amplify radiation in the 1020–1080 nm spectral bandwidth. Alternatively, pumping at 915 nm allows producing emission at 976 nm under specific conditions exploiting the three-level operation [1]. Recently, an Yb-doped fiber laser delivering up to 94 W at 976 nm in the continuous-wave regime has been demonstrated [2, 3]. Based on a similar approach, a millijoule-class laser at 976 nm operating in the Q-switch regime with up to 70 W average power has been achieved [4].