Effects of Light Source Coherence and Offset-Launching Distance on Performance in 49.4 km Power over Multimode Fiber Systems

Based on the offset-launching (OL) scheme, the effects of light source coherence and OL distance on the power performance of the 49.4 km power over fiber (PoF) system using multimode fiber are systematically investigated. We analyzed the effects of light source coherence and OL distance on the maximum output power by constructing PoF experimental systems with four different light sources and 30 μm OL ranges. The experimental results show that the OL scheme can significantly enhance the output power in PoF systems with different light source and OL distance configurations. For coherence, the 20 nm light source with weaker coherence performs best in the 10.8 km–36 km PoF link, the advantage of the 12 nm light source is gradually reflected in the range 41 km–49.4 km, and the 2 nm light source is expected to realize the optimal output power in longer-distance. For OL distance, the 20 nm light source performs best in the range of 0–12.5 μm, and the 12 nm light source shows the best performance after exceeding 15 μm. This paper summarizes the optimal light source and OL distance configurations, the work provides ideas for performance enhancement and optimal design of the PoF system, as well as an experimental basis for energy supply to remote devices.