Switchable generation of rectangular noise-like pulse and dissipative soliton resonance in a fiber laser

We report on the switchable generation of a rectangular noise-like pulse (NLP) and a dissipative soliton resonance (DSR) in a fiber laser with highly nonlinear effect at very low pump power. The NLP centered at 1530.5 nm demonstrates a new characteristic that its profile evolves gradually from rectangular shape to Gaussian-like shape with the increasing pump power. By appropriately manipulating the polarization controller (PC), the laser switches emit a DSR pulse centered at 1551.3 nm. The duration of the DSR could broaden from 17.4 ns to the cavity round trip time with increasing the pump power, while keeping the pulse profile and the intensity unaltered. This type of fiber laser may not only facilitate further investigations of the characteristics of NLP and DSR but also serve as a multi-functional optical source for potential applications.