100 μJ single-frequency linear-polarized fiber amplifier at 1550 nm based on 12-μm core diameter Er/Yb co-doped fiber

A 101.3 μJ single-frequency linear-polarized pulsed laser at 1550 nm was demonstrated from a 12-μm core diameter fiber amplifier. The pulse width and repetition rate were 387 ns and 10 kHz, respectively, corresponding to a pulse peak power of 262 W. Narrow linewidth of 780 kHz was measured with a delayed self-heterodyne method and the optical signal-to-noise ratio was over 45 dB without the observation of the ASE around 1 μm.