Dissipative soliton mode-locked all-fiber laser with a broad spectral bandwidth

We demonstrate an all-fiber dissipative soliton fiber laser (DSFL) with a very broad spectral bandwidth by optimizing the cavity design of the fiber laser. Two different cavity schemes of the DSFL with simple cavity structures were built by employing a hybrid component, and their properties were investigated while varying the net cavity dispersion of the laser. By optimizing the cavity dispersion of the fiber laser, we achieved a DSFL that stably deliver linear chirped pulses with a pulse duration of 912.5 fs at a repetition rate of 52.2 MHz without additional pulse compression. The measured spectral bandwidth of the laser was 68 nm, which is the largest value ever reported for Er-doped DSFL oscillators.