Dynamics of nanosecond pulsed pump ytterbium-doped double-clad fiber amplifier

Pulsed pump is an effective method to suppress the amplified spontaneous emission (ASE) between pulses of high power pulsed fiber lasers. For the pulsed pump, the most important factors need to be determined during amplifier design are the pump power (PP) and pump duration (tp). In this paper, the high power ytterbium-doped double-clad fiber amplifier with pulsed pump is numerically studied. The relationship between pulse energy, efficiency and ASE with pump power and duration is investigated and experimental results are provided. The conclusions are valuable for the design of pulsed pump fiber amplifiers.