Optical networking is a technology that uses light to transmit data between devices. It offers high bandwidth and low latency, and has been the standard for long-distance data communications for many years. Fiber optics are used for most long-distance voice and data communications around the world.

Optical networking has a long history, and as its services and use cases expand, the trend to make it more flexible, intelligent and efficient will continue to grow.

The technology behind optical networking is based on the principle of total internal reflection. When light hits the surface of a medium such as a fiber optic cable, some of the light is reflected by the surface. The angle at which light is reflected depends on the properties of the medium and the angle of incidence (the angle at which the light hits the surface).

If the angle of incidence is greater than the critical angle, then all light is reflected; this is called total internal reflection. Total internal reflection can be used to make optical fibers, a type of glass or plastic that guides light along its length.

As light travels through an optical fiber, it undergoes multiple total internal reflections, causing it to bounce off the fiber walls. This bouncing effect causes light to travel down the length of the fiber in a zigzag pattern.

By gaining a detailed understanding of the characteristics of optical fibers, engineers can control the amount of reflected light and the distance it travels before being reflected again. This enables them to design optical fibers that can transmit data over long distances without losing any information.

Optical networks consist of several components: optical fibers, transceivers, amplifiers, multiplexers, and optical switches.

Optical Fiber
Optical fiber is the medium that carries optical signals. It is composed of a variety of materials, including:
Core: The center that carries the light.
Cladding: The material that surrounds the core and helps keep the optical signal contained.
Coating: A material that protects an optical fiber from damage.
The core and cladding are usually made of glass, while the coating is usually made of plastic.

Transceivers
Transceivers are devices that convert electrical signals to optical signals and vice versa, usually at the last mile of the connection. It is the interface between an optical network and the electronic devices, such as computers and routers.

Amplifier
An amplifier is a device that amplifies light signals so they can travel long distances without losing strength. Amplifiers are placed at regular intervals along the fiber to boost the signal.

WDM
A WDM(wavelength division multiplexer) is simply a device that takes multiple signals and combines them into a single signal. This is done by assigning each signal a different wavelength of light, allowing a multiplexer to send multiple signals down a single fiber simultaneously without interference.

Optical Switch
An optical switch is a device that routes optical signals from one optical fiber to another. Optical switches are used to control traffic in optical networks and are typically used in high-capacity networks.