Waveform-variable multi-wavelength erbium-doped random fiber laser

A waveform-variable and stable multi-wavelength erbium-doped random fiber laser (EDRFL) based on four-wave mixing has been proposed and demonstrated. The transition from a singlepeak waveform to a double-peak waveform is achieved by adjusting the polarization state, and a stable multi-wavelength output is contributed to the four-wave mixing effect in a highly nonlinear fiber (HNLF). In the case of setting the power of the 980nm pump laser to the same value, it is found that the double-peak waveform has higher output power, better flatness and stability, while the single-peak waveform has a higher signal-to-noise ratio and a lower threshold pump power. Therefore, the EDRFLhas the potential tomeet the requirement for variable waveform output of different systems.