32-nJ 615-fs Stable Dissipative Soliton Ring Cavity Fiber Laser With Raman Scattering

We report on a 32-nJ 615-fs stable dissipative soliton (DS) fiber laser in the presence of stimulated Raman scattering (SRS) in a long ring cavity. We found that a transition from noiselike pulses to dissipate soliton occurred at sufficiently high power in a nonlinear amplified loop mirror (NALM). Accompanied with the transition was a surge of pulse energy and suppression of Raman emission-the residual Raman emission counts only ~1% of energy in the output pulse. We attribute this transition to the shift of the transfer function in the NALM. Our results clearly show that the DS energy can be scaled up further in a long cavity even in the presence of Raman scattering. However, despite the increase of SRS threshold, further DS energy scaling may still be limited by SRS.