Tunable dual-wavelength laser in the 2 μm region, based on a polarization-maintaining large mode area thulium-doped fiber

We present the development of a tunable dual-wavelength fiber laser, based on a thulium-doped fiber and Volume Bragg Gratings (VBG). Dual-wavelength difference is continuously tunable from 1 nm to 144 nm (0.08-11.47 THz).