Burst-mode Yb-doped fiber amplifier system optimized for low-repetition-rate operation

We report on the burst-mode operation of a polarization-maintaining Yb-doped multi-stage all-fiber amplifier capable of generating 10-pulse 100 ns long bursts of 400 mu J total energy. The corresponding average energy per pulse is 40 mu J, with a standard deviation of 16%. The 40 mu J pulses are compressible to a full width at half-maximum of 500 fs. The burst repetition rate is set to 1 kHz and the amplifier is synchronously pulse pumped to minimize amplified spontaneous emission (ASE) between the bursts. A special amplifier design has been developed to suppress ASE further at the cost of lower power efficiency. A detailed investigation of gain and ASE suppression performance of the amplifier in relation to pulsed pumping is presented. (C) 2015 Optical Society of America