Black phosphorus saturable absorber for dual-wavelength polarization-locked vector soliton generation

Abstract

We report the usage of few-layered black phosphorus (BP) as saturable absorbers (SAs) to achieve dual-wavelength vector solitons mode locking in an erbium-doped fiber laser for the first time, to our knowledge. The SA is fabricated based on liquid exfoliation method by incorporating BP nanosheets with polyvinyl alcohol. We have demonstrated that the saturable absorption of BP is polarization independent. The laser is capable of generating dual-wavelength polarization-locked vector solitons centered at ~1533 and ~1558 nm with the bandwidths of ~3.7 and ~6.9 nm simultaneously. The results indicate the potential applications of few-layered BP as broadband SAs in vector soliton pulses generation.