Stimulated Brillouin scattering threshold dependent on temporal characteristics in a kilowatt-peak-power, single-frequency nanosecond pulsed fiber amplifier

The stimulated Brillouin scattering(SBS) threshold affected by repetition rate and pulse duration in a singlefrequency nanosecond pulsed fiber amplifier is studied. The experimental results demonstrate that the SBS threshold can be improved either by reducing the repetition rate or by narrowing the pulse duration; however,the average power may be limited in some cases. Otherwise, two evaluation methods for the SBS threshold in the fiber amplifier are compared and discussed, aiming to obtain a more accurate description for the SBS threshold in our single-frequency amplifier system.