The operation of a single-clad Ho<sup>3+</sup>, Pr<sup>3+</sup>-fluoride [zirconium, barium, lanthanum, aluminum, and sodium (ZBLAN)] fiber laser pumped by an Nd: yttrium-aluminum-garnet (YAG) solid-state laser operating at 1064 nm has been demonstrated. An output power of more than 600 mW was generated at a slope efficiency of 9% after a threshold of ~ 200 mW was reached. The center wavelength was 2854 nm for low-launched powers of < 2 W and was shifted to 2874 nm for higher launched pump powers. Excitation is predominantly into the Ho<sup>3+</sup> (<sup>5</sup>I<sub>6</sub>) level, with the Pr<sup>3+</sup> acting to deplete the Ho<sup>3+</sup> lower laser level. The relatively small slope efficiency and low output power is attributed to the small absorption coefficient of Ho<sup>3+</sup> at 1064 nm, as well as to the additional loss that was caused by excited-state absorptions (ESAs) at the pump wavelength from both Ho<sup>3+</sup> and Pr<sup>3+</sup> ions.
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