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. When we say “Wired Routers” we mean networking devices which only have wired Ethernet ports for connecting Local Area Network (LAN) devices to them (such as local computers, laptops, gaming consoles, smart TVs etc). Which either needs a fiber optic port, or an SFP port, plus a fiber otpic-to-sfp tranceiver. The good news: you can bridge them easily using the right hardware, such as media. The initial standard for Gigabit Ethernet was produced by the IEEE in June 1998 as IEEE 802. 3z, and required optical fiber. 3z is commonly referred to as 1000BASE-X, where -X refers to either -CX, -SX, -LX, or (non-standard) -ZX.