  We describe an efficient laser emission from a directly grown Er3+:YAG
single-crystal fiber that is resonantly pumped using a continuous-wave (CW)
laser diode at 1532 nm. In a longitudinal pumping, it emits 12.5 W at 1645 nm
with a slope efficiency of 32%, which is the highest ever reported for a
directly grown Er:YAG single-crystal fiber laser. Using an off-axis pumping
scheme, CW output powers up to 7.3 W can be reached and in Q-switched
operation, the laser produces 2 mJ pulses with a duration of 38 ns at the
repetition rate of 1 kHz with an M^{2} factor below 1.8. To our knowledge this
is the first directly grown Er3+:YAG single-crystal fiber Q-switched laser. In
dual-side pumping scheme a laser emission at 1617 nm is achieved with output
powers up to 5.7 W representing the highest output power ever achieved by a
diode-pumped Er:YAG laser at this wavelength.
