Dual square-wave pulse passively mode-locked fiber laser

作者:Su, Qingchao; Wang, Tianshu*; Zhang, Jing; Ma, Wanzhuo; Liu, Peng; Su, Yuwei; Jia, Qingsong
来源:Applied Optics, 2017, 56(17): 4934-4939.
DOI:10.1364/AO.56.004934

摘要

We study a passively mode-locked square-wave pulse (SWP) fiber laser with a nonlinear amplifying loop mirror in the cavity. The net dispersion of the cavity is about 0.68 ps(2) and the SWP mode-locked fiber laser can be realized. The peak power of the SWP hardly varies and the pulse duration gets expanded with the increasing pump power. SWPs breaking in the low nonlinear cavity can be observed and the stable dual SWP can be achieved in the experiment. When the total pump power stays at 800 mW, the interval of dual pulses is 41 ns. The widths of dual SWPs are both 1.5 ns. The output power rises linearly with the increasing of the pump power, while the interval of dual SWPs is almost constant. Then, the physical mechanism of the SWP breaking and vector nature of the pulse are analyzed.