Power-Over-Fiber Using Double-Clad Fibers

Power-over-fiber (PWoF) is an attractive technology for transmitting power utilizing optical fibers. Because optical fibers are nonconductive power lines, and can transmit data signals simultaneously, PWoF enables us to provide usages that are not feasible with conventional electric power supply systems using copper wires. This study presents an overview of PWoF using various types of optical fibers, and introduces a practical application for powering remote antenna units (RAUs) in mobile communications. To power a RAU, the author’s group has worked on PWoF using double-clad fibers, which comprise a single-mode core and an inner cladding that surrounds the core. The core structure is more suitable for simultaneous high-speed data signals and high-power feed light transmission than other optical fibers. To demonstrate the feasibility, the experimental demonstrations of the authors’ group are introduced in detail. In addition, the latest performance comparison of PWoF reported so far is presented, and future prospects are described.