Tunable and switchable dual-wavelength mode-locked Tm3+-doped fiber laser based on a fiber taper

We demonstrate a self-starting dual-wavelength mode-locked fiber laser at a 2 mu m spectral region by using a fiber taper in a Tm3+-doped ring fiber cavity. The fiber taper fabricated with a flame brushing technique was used as a periodic filter with a modulation depth of similar to 3.61 dB and a modulation period of similar to 7.3 nm, respectively. Diverse dual-wavelength regimes including continuous wave (CW)/multi-soliton, soliton/multi-soliton, and soliton/soliton regimes were obtained by adjusting pump power. Wavelength tuning for the dual-wavelength was also precisely controllable through stretching the fiber taper carefully. The tuning range was similar to 7 nm which was limited by the modulation period of the taper. By inserting a 10.0 m dispersion compensation fiber (DCF) into the fiber cavity, a stable dual-wavelength dissipative-soliton operation was obtained at 2 mu m spectral region for the first time. (C) 2016 Optical Society of America