In this Letter, we demonstrate an ultrabroadband (1700-1900 nm) tunable Tm-doped fiber laser (TDFL) generating dissipative solitons in the net-normal dispersion regime. The laser delivers pulses with spectral widths ranging from 10 nm to 23 nm and pulse durations from 8.7 ps to 18.3 ps. Stretched-free pulse amplification at the gain edge (1708 nm) and gain peak (1807 nm) is implemented to demonstrate the range of further power scalability of the laser signal. The maximum achieved power in a one-stage Tm-doped amplifier is 140 mW with a compressed pulse duration of 478 fs. Considering the diverse utility of this wavelength band, this laser is highly desirable for applications such as optical sensing, biological imaging, and industrial machining.