MXene and PtSe2 saturable absorbers for all-fibre ultrafast mid-infrared lasers

We report on the feasibility of MXene and platinum diselenide (PtSe2) as novel saturable absorbers for the development of wavelength stabilized passively mode-locked mid-infrared fibre laser systems. After evaluating the performance of individual absorbers in a test cavity, we demonstrate a linear all-fibre laser cavity that utilizes a high reflective chirped fibre Bragg grating for wavelength selective feedback. The observed mode-locked pulse train from this Er3+:ZBLAN fibre laser has a 37 MHz repetition rate with an average power of 603 mW and a spectral width of 721 pm. Our results show that MXene and PtSe2 are promising nonlinear materials for all-integrated ultrafast fibre laser cavities for the important mid-infrared spectral region.