Switchable and tunable dual-wavelength passively mode-locked fiber laser

We demonstrate a switchable and tunable dual-wavelength passively mode-locked fiber laser in a compact linear cavity. Two cascaded polarization-maintaining fiber Bragg gratings (PM-FBGs) are used as wavelength-selective components, and a semiconductor saturable absorber mirror (SESAM) is used as a mode-locked component. Four kinds of switchable single-wavelength and two kinds of switchable dual-wavelength mode-locked operations are achieved in 1.0-μm band under lower pump power condition. Through temperature control, we obtain the tunable single-wavelength and dual-wavelength mode-locked operations, and the tunable wavelength range is about 0.5 nm when increase the temperature from 25 °C to 80 °C.