Study on DSR Square Wave Pulse Compression in Er-doped NALM Mode-Locked Fiber Laser

We first demonstrate the compression of square wave dissipative soliton resonance pulse in Er-doped NALM mode-locked fiber laser. The pulse width can be tuned from 0.712 ns to 1.881 ns by adjusting the polarization controller in the cavity, and different pulse width corresponds to different operating power from 25.02 mW to 27.99 mW in the cavity. It is found that there is an optimal operating power 26.82 mW for the square wave pulse to obtain the maximum compression ratio 18.98% of pulse width.