Observation of spaced pulse burst in MoS₂ film passive Q-switched linear-resonator Yb³⁺-doped fiber laser based on a distributed Bragg reflector

To the best of our knowledge, we propose and present the first fiber laser of a molybdenum sulfide (MoS 2 ) film with passive Q-switched Yb 3+ -doped linear configuration based on a distributed Bragg reflector to generate a spaced pulse burst. A spaced pulse burst with five sub-pulses, a full width at half-maximum (FWHM) of 65.0 ns and an output power of 32.1 mW were achieved from a 2 m length Yb-doped silica fiber and a 36 µ m thickness MoS 2 film saturable absorber. The FWHM of the sub-pulses changes from 10.2 to 25.4 ns. The forming mechanism of the spaced pulse burst is also reported. This research provides a new light source for the development of refinement process steps for material processing.