2.5 mJ Narrow-Linewidth, Linearly-Polarized Pulse-Burst High-Power Yb-Doped Fiber Amplifier System

Fiber sources for high-energy bursts of pulses are attractive for use in coherent pulse stacking (CPS) [1,2], and can avoid damage and excessive nonlinearities even at extracted energy of several times the saturation energy. CPS has so far been used with chirped pulse amplification, but it can also be used for narrow-linewidth pulses, which can be severely limited by the potentially low threshold of stimulated Brillouin scattering. Here, we present a high-energy narrow-linewidth linearly-polarized pulse-burst Yb-doped fiber MOPA system, which can be used for CPS when combined with appropriate amplitude and phase control. A long coiled booster fiber mitigates thermal effects even at high power and maintains polarization by virtue of a low birefringence.