Definition: communication systems consisting of fiber-optic links
A fiber-optic network is a system for optical fiber communications which consists of a number of fiber-optic links and additional components which make it possible to send data from any node of the network to any other one. This technology heavily builds on fiber optics. It mostly works with glass fibers, but for short-distance transmission it may also contain plastic optical fibers.
Figure 1: Schematic of a fiber-optic link for a point-to-point connection. More complicated networks can be made, e.g. with a ring or star topology.
Optical networks are grouped according to the area covered:
A local area network (LAN) links two or more points within a small area, e.g. within a building or between a few buildings.
A metropolitan area network (MAN) covers a larger area, e.g. that of a city.
A wide area network (WAN) extends over a larger area, e.g. a whole country or even more.
Typically, larger-scale networks are built by connecting smaller-scale networks. For example, metropolitan networks can be connected to form a wide area network.
Another distinction is that of active optical networks, containing active components such as fiber amplifiers, and passive optical networks (PON), using only passive components such as optical filters and splitters (apart from the always required transmitters and receivers).
According to the data rate, additional attributes can be given. For example, GPON means gigabit PON, which is a passive optical network with a downstream data rate of 2.5 Gbit/s and an upstream rate of 1.25 Gbit/s.
