SafekipediaOptical networking is a way to send information using light. It works by putting signals into light and sending them through special networks. These networks can be small, like those in a school or office, called local-area networks. Or they can cover big areas, like cities or whole countries, called wide area networks.
This kind of networking uses tools such as optical amplifiers, lasers, LEDs, and a method called wavelength-division multiplexing to send lots of data. The data moves through thin glass fibers, called fiber-optic cables. Because optical networking can handle so much information very fast, it helps make the Internet and other communication systems work. Today, most information we send and receive—like video calls, webpages, or data between machines—travels through these quick optical networks.
Types
Fiber-optic networks
Main article: Fiber-optic communication
Fiber-optic networks are a good way to send information over long distances. They use very thin glass or plastic fibers to carry light signals. These networks can be set up in cities, countries, or even around the world. Some fiber-optic networks share one connection with many homes or businesses using special splitters.
Free-space optical networks
Free-space optical networks work like fiber-optic networks but they send signals through the air instead of using fibers. This can be done between satellites in space, like with SpaceX's Starlink, or between high-altitude balloons, such as in Google's Project Loon and Facebook Aquila. These networks can also connect computers over short distances on the ground, like on a school campus.
Components
An optical networking system uses several key parts to send information with light. It needs fiber, which can be multi-mode or single-mode. A light source, like a laser or LED, provides the signal. Other important parts include devices that combine or separate signals, such as multiplexers/demultiplexers, and tools that direct or split the light, like optical switches and splitters. Optical amplifiers help make the light signal stronger as it travels through the fibers.
These parts work together to let lots of data move quickly over long distances through fiber-optic cables.
Main article: Multiplexer/demultiplexer
Main articles: Optical Add/Drop Multiplexer, Reconfigurable Optical Add/Drop Multiplexer
Main article: Optical switch
Main article: Optical splitter
Main article: Circulator
Main article: Optical amplifier
Main article: Wave division multiplexer
Transmission medium
In the past, networks used copper wires to send information. These wires could only carry a limited amount of data and had problems when signals got too close together.
Later, scientists discovered that light could carry much more data without these problems. They developed special glass fibers that could guide light over long distances. These fibers could carry thousands of times more information than old copper wires, making modern communication faster and more efficient.
Optical amplification
Fiber optic networks can send more information thanks to special tools called optical amplifiers. These amplifiers make light signals stronger as they travel through the cables.
One important type is the erbium-doped optical amplifier (EDFA). It was created in 1986 by David Payne at the University of Southampton. This amplifier uses special atoms to boost the light signal.
As networks grew, many kinds of amplifiers were developed. EDFAs became very popular, especially for systems that need to send many signals at once. Today, these amplifiers are important parts of networks that handle lots of data.
Wavelength division multiplexing
Wavelength-division multiplexing (WDM) made it possible for fibers to carry much more information. It uses different colors of light, or wavelengths, to send many signals at the same time through one fiber. At first, systems had only a few channels, but new technology allowed many more.
Companies worked to improve this technology. In 1996, a system with 16 channels was put into use on a big network, showing how strong WDM could be. This helped start the field of optical networking.
Main article: Wavelength-division multiplexing
Capacity
Wavelength-division multiplexing (WDM) made it possible to send many light paths through a single fiber optic. This helped the Internet grow a lot in the 1990s. Since then, WDM systems have gotten better and better.
Some systems can now send huge amounts of data very quickly. For example, in 2018, a system could send enough data to stream over a million 4K Ultra HD videos at once.
Because WDM can carry so much information, it has become very important for most global communication networks and the Internet. People need more and more bandwidth for things like watching videos online, using mobile phones, and cloud computing. By 2022, the amount of data moving over the Internet was growing very fast, with most of it being video content sent through optical networking.
Standards and protocols
Synchronous optical networking (SONET) and synchronous digital hierarchy (SDH) are the main ways optical networks send information. The optical transport network (OTN) protocol, made by the International Telecommunication Union, helps these systems work together. These systems can carry many kinds of data, like ATM, Ethernet, and TCP/IP.
Main article: Synchronous optical networking
This article is a child-friendly adaptation of the Wikipedia article on Optical networking, available under CC BY-SA 4.0.