We report on the dark pulse emission of an all-normal dispersion erbium-doped fiber laser with a polarizer in cavity. We found experimentally that apart from the bright pulse emission, under appropriate conditions the
fiber laser could also emit single or multiple dark pulses. Based on numerical simulations we interpret the dark pulse formation in the laser as a result of dark soliton shaping.
Han Zhang, Dingyuan Tang, Luming Zhao and Wu Xuan,“Dark pulse emission of a fiber laser’’ Physical Review A, 80, 045803 (2009).