Closed-Loop Power-Over-Fiber System With Real-Time Feedback Control for Dynamic Load Adaptation

Power-over-fiber (PoF) systems suffer from energy waste and instability under dynamic conditions due to fixed laser output and time-varying load demands. This study presents a closed-loop feedback control mechanism based on capacitor-voltage monitoring, which effectively filters transient disturbances while accurately reflecting system energy balance. Employing an 808 nm laser with 12 W maximum output, the system uses a GaAs-based photovoltaic power converter (PPC) with high measured MPP efficiency under our test conditions and a Proportional-Integral-Derivative (PID) algorithm to achieve rapid response, automatic compensation for fiber losses up to 1500 m, and 17.9% end-to-end efficiency over 500 m fiber, while ensuring long-term reliability with stable operation exceeding 3000 s. A practical WiFi access scenario with live video streaming is further demonstrated, validating stable closed-loop powering under traffic-driven load dynamics.