An optical network is a type of data communication network built with optical fibre technology. It uses optical fibre cables as the primary communication medium for converting data and passing data as light pulses between sender and receiver nodes.

An optical network is also known as an optical fibre network, fibre optic network or photonic network. Fibre optic refers to the technology and medium used in the transmission of data as pulses of light through a strand or fibre medium made of glass or plastic (optical fibre), versus being sent as electrical pulses through conductive metal, like copper wires. Optical fibre technology can carry much more data than conventional copper wires and is less prone to electromagnetic interference, simply because data is transmitted in the form of light, rather than electricity.

Through its use of light as a transmission medium, an optical network is one of the fastest communication networks. It works by using an optical transmitter device to convert an electrical signal received from a network node into light pulses, which are then placed on a fibre optic cable for transport to a receiving device.

Unlike copper-based networks, the light pulses of an optical network may be transported quite a distance until the pulses are regenerated through an optical repeater device. After a signal is delivered to a destination network, it is converted into an electrical signal through an optical receiver device and sent to a recipient node.

Moreover, an optical network is less prone to external inference and attenuation and can achieve substantially higher bandwidth speeds than copper networks.