Generation of periodical pulse bundles in a self-pulse fiber laser

The periodical pulse bundles were presented in a Yb-doped double-clad distributed Bragg reflector all-fiber configuration. With a pumped power of 529.2 mW, the periodical pulse bundles is obtained. Furthermore, a single pulse bundle composes of one main pulse and two sub-pulses. The pulse width of the main pulse and the sub-pulse are 2.2 μs and 7.7 μs, respectively. The separations of between main pulse, right sub-pulse and left are 22.70 μs and 22.15 μs, respectively. The average period of the pulse bundle is approximately 75 μs with repetition rate of 13.3 kHz. The number of sub-pulses between adjacent main pulses decreases to one when the pumped power does to 450.2mW. When the pumped power increases to 594.4 mW, the number goes to three.