Low-Noise, Single-Frequency, All-Fiber, 50 W-Class Laser Source at 1844 NM for Quantum Applications

Thulium-doped fiber amplifiers (TDFAs) offer emission across 1600 nm-2100 nm. Conventional systems utilize high-power 793 nm cladding-pumped lasers to span 1900 nm-2000 nm, yet the critical 1800 nm-1900 nm range remains underexplored, despite its importance in quantum technologies, such as generating high-power 840 nm sources through nonlinear sum frequency generation (SFG) with 1550 nm lasers. While Meleshkevich et al. (2005) demonstrated a 10 Wall-fiber system at 1780 nm using 1567 nm core-pumping [1], this approach faces scalability challenges due to the limited availability of high-power, single-mode laser sources near 1570 nm. Burns et al. (2019) achieved 47 W at 1726 nm using an 80 W erbium-doped fiber laser at 1580 nm with free-space injection and non-PM fibers [2], which are unsuitable for demanding quantum computing applications. Here, we present a polarized, all-fiber laser system operating at 1844 nm, delivering up to 47 W.