We report on a triple clad large mode area Tm-doped fiber laser with 18 μm core diameter manufactured by an alternative manufacturing process named Repusil. The fiber characterization in a laser configuration provides a slope efficiency of 47.7 % at 20˚C, and 50.4 % at 0˚C with 8 W output power, with a laser peaks emission at 1970 nm. Finally, a beam quality near the diffraction-limit (M²x,y <1.1) is proved.