Suppression of Q-switched spikes in an all-fiber acousto-optic oscillator

Multi-spike phenomenon, arising from the periodic intensification of amplified spontaneous emission (ASE), is a characteristic feature of actively Q-switched fiber lasers. This localized high peak power preferentially triggers nonlinear effects such as stimulated Raman scattering (SRS). Here, we demonstrate multi-parameter optimization of multi-spike suppression in an all-fiber acousto-optic Q-switched laser oscillator. By synergistically regulating laser parameters including pump power, modulation duty cycle, and rising time, the temporal dynamics of Q-switched pulses are comprehensively characterized. After elucidating the underlying physical mechanisms, the optimized parameter set enables stable single-peaked pulse operation with minimal leading-edge distortion.