Power-efficient Triple-cladding Four-core Fiber Amplifier with Advanced Hybrid Pumping Technique

We propose an advanced hybrid pumping (AHP) technique for multi-core fiber (MCF) amplifiers to improve power efficiency. Unlike conventional hybrid pumping that requires multiple single-mode pump lasers, AHP enables simultaneous core and cladding pumping using a single multimode pump laser. Numerical simulations and experiments confirm that AHP enhances both power conversion efficiency (PCE) and noise figure (NF) by increasing pump density in the cores. Using a triple-cladding four-core erbium-doped fiber, we achieved a PCE of 17.6% and an output signal power exceeding 400 mW per core. These results demonstrate the potential of AHP for energy-efficient MCF optical transmission systems.