Power over fiber for undersea applications

This study presents a water-tight laser-based Power over Fiber (PoF) system designed to deliver electrical power to underwater sensors located hundreds of meters away. The optical Power Distribution System (PDS) employs two near-infrared (NIR) laser diodes coupled with telecom-grade fiber optic cables, delivering up to 3 watts of electrical power each to two separate receiver systems that use photovoltaic (PV) cells for optical-to-electrical conversion. The system achieves a 10-15% end-to-end efficiency. The laser transmitter housing, receiver housing, fiber-optic cable, and connectors are rated for depths up to 200 meters and have been tested up to 140 meters. The optical PDS has logged over 5,700 hours of continuous operation in a test tank at room temperature, demonstrating thermal and electrical stability. PoF solutions for undersea applications could significantly enhance power delivery by reducing common issues associated with copper cables, providing neutrally buoyant tethering options, and potentially enabling innovative methods for distributing electricity in underwater environments.