High-energy noise-like pulses generated by an erbium-doped fiber laser incorporating a PbS quantum-dot polystyrene composite film

We demonstrate a high-energy noise-like pulse (NLP) generated by an Er-doped fiber (EDF) laser incorporating a PbS quantum dot (QD) polystyrene (PS) composite film as a saturable absorber (SA). Benefitting from the intrinsic properties of NLPs and the high damage threshold of the PbS QD PS composite film, a stable NLP train can be obtained with an output power of 96.3 mW at a pump power of 660 mW, corresponding to a pulse energy of 9.68 nJ. This represents the highest pulse energy ever reported in an NLP EDF laser incorporating material-based SAs. The slope efficiency reached 17.37% and the steady NLP operation was able to be maintained for several hours under laboratory conditions. Our experimental results prove that the PbS QD PS composite film can serve as an effective SA to realize high-energy pulses in a mode-locked fiber laser.