Laser emission in the range of $1.88–1.99\mu \mathrm{m}$ from a ${\mathrm{Tm}}^{3+}$ -doped tellurite fiber is demonstrated when pumped with a diode-pumped ${\mathrm{Er}}^{3+}∕{\mathrm{Yb}}^{3+}$ -doped silica fiber laser operating at $1.57–1.61\mu \mathrm{m}$ . This pump source excites the ${\mathrm{Tm}}^{3+}$ ions directly into the ${}^{3}F_4$ upper laser level and yields an output power of $280\mathrm{mW}$ with a slope efficiency of 76% in a 99%–12% laser cavity arrangement and a $32\mathrm{cm}$ long fiber. This result is very close to the Stokes efficiency limit of $\sim 80\%$ . This is, to the authors’ knowledge, the first demonstration of high efficiency lasing in a tellurite fiber at wavelengths longer than $1.56\mu \mathrm{m}$ .