This device is a small transceiver you plug into a switch, router, or server. It can also turn optical signals back into electrical signals for copper cables. This lets you. Optical switching represents a fundamental technological evolution, shifting data routing from the domain of electrons to the realm of photons, or light. They're a core component in fiber-optic networks, where data travels as pulses of light through glass fibers. This lets you send data far away. SFP modules work in many network. An SFP (Small Form-factor Pluggable) is a compact, hot-pluggable transceiver module that allows networking equipment — including switches, routers, servers, and media converters — to support different physical media, such as optical fiber or copper, without replacing the host hardware.