Ultrafast erbium doped fiber laser modulated by Nb₄AlC₃ saturable absorber

Conventional soliton mode-locked erbium-doped fiber laser is realized by MAX phases material (MAX-PM) of Nb4AlC3 as saturable absorber. First, Nb4AlC3 nanosheets are prepared by liquid phase exfoliation method, and a piece of taper-fiber is adopted to fabricate Nb4AlC3-SA. The saturation intensity and modulation depth of the Nb4AlC3-SA are 2.02 MW/cm2 and 1.88 %. Based on the Nb4AlC3-SA, conventional soliton (CS) mode-locked EDF laser is achieved. The central wavelength, pulse duration, and pulse repetition rate are 1565.65 nm, 615.37 fs, and 24.63 MHz. The performance are competitive and particularly superior in terms of pulse duration. To the best of our knowledge, this is the first report of Nb4AlC3 material is used as modulator for ultrafast pulse generation. The work fully confirms that Nb4AlC3 possesses marvellous nonlinear saturable absorption property, as well broadens new avenues and opportunities for further research of air-stable ultrafast photonic devices.