Wikipedia
Power-over-fiber
Power-over-fiber, or PoF, is a technology in which a fiber optic cable carries optical power, which is used as an energy source rather than, or as well as, carrying data. This allows a device to be remotely powered, while providing electrical isolation between the device and the power supply. Such systems can be used to protect the power supply from dangerous voltages such as from lightning, or to prevent voltage from the supply from igniting explosives.