The short answer is no - RJ45 connectors are designed for electrical Ethernet signals, while fiber optics transmit light pulses through glass or plastic. However, modern networks often combine both technologies. Fiber to Ethernet Converters use a copper transceiver to transform the signal from a RJ45 Ethernet link to one that can be used by a fiber optic transceiver, and vice versa. This guideline assists the contractors. Ethernet cables are networking cables that connect devices—like computers, routers, and switches—within a Local Area Network (LAN).