Highly efficient, high energy pulse-burst Yb-doped fiber laser with transform limited linewidth

A 1um fiber laser outputting high energy (>1mJ) pulse-bursts with high peak powers (>15kW) and narrow linewidth (<300MHz) is an attractive pump source for tunable periodically poled crystal (PPx) based OPA's which are used in gas sensing, imaging and communication applications. Here a turn-key 1064nm PM Yb-doped fiber amplifier capable of generating high pulse burst energies with transform limited linewidth is presented. The similar to 20W average power capable laser is optimized for high energy (0.5-2mJ) and high peak power (>10kW) operation at low duty cycles (<0.1%). The laser is capable of operating at >10x the saturation energy level of the final stage gain fiber and achieves a high level of pulse-to-pulse peak power uniformity within pulse-burst. Stimulated Brillion Scattering (SBS) limited micro pulse energy up to 40uJ is achieved and SBS dependence on micro pulse width and separation are characterized. High wall plug efficiency (>20%) for the FPGA controlled system is maintained by temporal and spectral ASE suppression and by spreading the necessary pulse pre-shaping losses (similar to 12dB) to three different amplitude modulation points in the amplifier chain.