High-power lasing at 900 nm in Nd³⁺-doped fiber: a direct coordination engineering approach to enhance fluorescence

Lasers at similar to 900 nm have been of vital importance in various fields, including material processing, underwater communications, and strong-field physics. Although Nd3+-doped materials have been employed for the similar to 900 nm laser, the similar to 900 nm emission is in strong competition with the often more dominating similar to 1060 nm emission, which strongly limits the output power and applications. This paper proposes a direct coordination engineering approach, which introduces halogen to the nearest coordination of Nd3+ in glass for increasing the bond covalency, leading to stronger emissions at similar to 900 nm than at similar to 1060 nm. Iodide-incorporated Nd3+-doped silica fibers show prevailing similar to 900 nm emission rarely observed in Nd3+-doped materials. Using the created fibers, a power (113.5W) 50 times higher than the current record is accomplished based on an all-fiber structure. Our approach holds the potential for regulating the spectroscopic properties of other rare-earth-doped laser materials. (c) 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement