1.064- and 1.32-µm Nd:YAG single crystal fiber lasers

We report the development of CW 1.06- and 1.32-μm fiber lasers made of short sections of Nd:YAG single crystal fibers optically end-pumped either with an Argon-ion laser (
\lambda = 0.5145\mu
m) or a single laser diode (
\lambda = 0.817\mu
m). High conversion efficiencies, a few milliwatt thresholds and 10-20 mW output powers are reported, as well as a good coupling efficiency to a standard single-mode fiber. Loss mechanisms and means of reduction are also investigated for a variety of fiber lasers in either guided or unguided configurations.