Synchronously pumped 3.5μm mode-locked fiber laser

In this paper, we demonstrate a synchronously pumped 3.5 μm mode-locked fiber laser based on the cross-phase modulation effect. The fiber laser delivered pulses with a central wavelength of 3541.8 nm, 3 dB spectral bandwidth of 5.1 nm, pulse repetition rate of 18.63 MHz, average output power of 50 mW, and signal-to-noise ratio of 68 dB. The Fourier transform limit pulse width is 2.6 ps, estimated by the hyperbolic secant curve.