  We report on a long wavelength emitting rare earth doped fiber laser with
emission centered at 3.5 {\mu}m and tunable across 450 nm. The longest
wavelength emission was 3.78 {\mu}m, which is the longest emission from a fiber
laser operating at room temperature. In a simple optical arrangement employing
dielectric mirrors for feedback, the laser was capable of emitting 1.45 W of
near diffraction limited output power at 3.47 {\mu}m. These emission
characteristics compliment the emission from quantum cascade lasers and
demonstrate how all infrared dual wavelength pumping can be used to access high
lying rare earth ion transitions that have previously relied on visible
wavelength pumping.
