0.5% Holmium (Ho) doped YAG single crystal fiber (SCF) was fabricated using the laser heated pedestal growth
(LHPG) method and amplification properties of the fabricated Ho:YAG SCF were studied. The relatively large lengthto-
diameter ratio provides guiding for both the pump and signal beams propagating in the SCF. The propagation and
gain of signals with different modes were studied. A numerical method based on finite difference (FD) beam
propagation method (BPM) combined with the rate equations was developed for theoretical simulation. The results are
encouraging to demonstrate the advantages of SCF for its fiber-like beam guiding property and solid state material gain
property. The simulation tool provides details about how the fiber shape and launched mode affect the gain and output
beam shape as well as predicts the amplification behavior of such unique specialty fibers.