High power mode-locked rod-type fiber femtosecond laser with micro-joule energy

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• To our knowledge, this is the first realization of the highest power of ANDi fiber laser by pure NPE mode-locking technique based on fibers with PM characteristic as gain media.

We report a high power all-normal-dispersion (ANDi) mode-locked laser based on nonlinear polarization evolution (NPE) technique using rod-type fiber with polarization maintaining (PM) characteristic. With 85 μm gain core diameter, 31 W of average power at repetition rates of 57.93 MHz, which corresponds to the pulse energy of 0.53 μJ, is demonstrated under a pump power of 93 W. The pulse duration of 124 fs after compressor is obtained at the central wavelength of 1033 nm as well as the measured power jitter of 0.3% over a period of 2 h.