This article takes you to understand what is an optical network?

Optical networking is a technology that uses light to transmit data between devices. It offers high bandwidth and low latency and has been the de facto standard for long-distance data communications for many years. Optical fiber is used for most long-distance voice and data communications worldwide.

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

Optical networking is important because it allows high-speed data transmission over long distances. For example, the optical network ensures that users in New York can access servers in Nairobi as fast as the laws of physics allow.

The technology behind optical networking is based on the principle of total internal reflection. When light hits the surface of a medium such as 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 the fiber, it undergoes multiple total internal reflections, causing it to bounce off the fiber wall. This bounce effect causes the light to travel down the length of the fiber in a zigzag pattern.

By carefully controlling the properties of the fiber, engineers can control how much light is reflected and how far it travels before being reflected again. This allowed them to design optical fibers that could 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 the optical signal. It is composed of a variety of materials, including:

• Core: The center that carries light.
• Cladding: A material that surrounds the core and helps keep the optical signal contained.
• Buffer Coating: A material that protects the fiber from damage.

The core and cladding are usually made of glass, while the buffer coating is usually made of plastic.

transceiver

Transceivers are devices that convert electrical signals into optical signals and vice versa, usually implemented in the last mile of a connection. It is the interface between an optical network and the electronic devices that use it, such as computers and routers.

amplifier

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

multiplexer

A multiplexer is just 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 the multiplexer to send multiple signals simultaneously along a single fiber without interference.

light switch

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

History of Optical Networking

The history of optical networking began in the 1790s when French inventor Claude Chappe invented the optical signal telegraph, one of the earliest examples of an optical communication system.

Nearly a century later, in 1880, Alexander Graham Bell patented the electro-optical telephone, an optical telephone system. While the Photophone was groundbreaking, Bell's earlier invention of the telephone was more practical and took a tangible form. Therefore, Photophone never left the experimental stage.

It wasn't until the 1920s that John Logie Baird in England and Clarence W. Hansell in the United States patented the idea of ​​using an array of hollow tubes or transparent rods to transmit images for television or fax systems.

In 1954, Dutch scientist Abraham Van Heel and British scientist Harold H. Hopkins each published scientific papers on tractography. Hopkins focused on unclad fibers, while Van Heel focused only on simple clad fiber bundles—a transparent cladding with a lower index of refraction around the bare fiber.

This protects the fiber reflective surface from external deformations and significantly reduces interference between fibers. The development of imaging beams was an important step in the development of optical fibers. Protecting the fiber surface from external interference allows for more accurate transmission of optical signals through the fiber.

By 1960, glass-clad fibers had losses of about 1 decibel (dB) per meter, suitable for medical imaging, but too high for communications. In 1961, Elias Snitzer of the Optical Company of America published a theoretical description of an optical fiber with a tiny core that could transmit light through only one waveguide mode.

In 1964, Dr. Kao proposed a light loss of 10 or 20 dB per kilometer. This standard helps to improve the range and reliability of telecommunication systems. In addition to his work on loss rates, Dr. Gao demonstrated the need for a purer glass to help reduce light loss.

In the summer of 1970, a group of researchers at Corning Glass Works began experimenting with a new material called fused silica. This substance is known for its extremely high purity, high melting point and low refractive index.

The team, consisting of Robert Maurer, Donald Keck and Peter Schultz, quickly realized that fused silica could be used to make a new type of wire called "optical waveguide fiber." This fiber optic wire can carry 65,000 times more information than traditional copper wire. Furthermore, the light waves used to carry information can be decoded at destinations even a thousand miles away.

This invention revolutionized long-distance communication and paved the way for today's fiber-optic technology. The team solved the decibel loss problem defined by Dr. Gao, and in 1973 John MacChesney at Bell Laboratories improved the chemical vapor deposition process for fiber production. As a result, commercial production of optical fiber cables has become possible.

In April 1977, General Telephone and Electronics Corporation used the fiber-optic network for the first time in Long Beach, California, for real-time telephone communication. In May 1977, Bell Labs soon followed suit, building an optical telephone communication system spanning 1.5 miles in downtown Chicago. Each pair of fibers can transmit 672 voice channels, equivalent to a DS3 circuit.

In the early 1980s, the second generation of fiber-optic communications was designed for commercial use, using a 1.3-micron InGaAsP semiconductor laser. These systems operated at bit rates as high as 1.7 Gbps in 1987 with repeater spacings of up to 50 kilometers.

The systems used in third-generation fiber optic networks operate at 1.55 microns and have a loss of about 0.2 dB per kilometer.

Fourth-generation fiber optic communication systems rely on optical amplification to reduce the number of repeaters required and wavelength division multiplexing (WDM) to increase data capacity.

In 2006, a bit rate of 14 terabits (Tb) per second was achieved on a 160-kilometer line using optical amplifiers. By 2021, Japanese scientists will be able to transmit 319 Tbps over 3,000 kilometers using a four-core fiber optic cable.

While these fourth-generation fiber-optic communication systems have a lot more capacity than previous generations, the basic principle is the same: convert electrical signals into optical pulses, send them over fiber optics, and then convert them back to electrical signals at the receiving end.

However, the components of each generation have become smaller, more reliable, and less expensive. As a result, fiber optic communications have become an increasingly important part of our global telecommunications infrastructure.

Key Trends in Optical Networking

Focus on the network edge

The optical network edge is where traffic flows in and out of the network. To meet the demands of cloud-based applications, optical networks are moving closer to end users. This allows for lower latency and more consistent performance.

Layer encryption

As cyber attacks become more common, data protection in motion will continue to be a major concern. SASE (Secure Access Service Edge), the use of cloud-native security features at service endpoints, has been gaining traction recently. Endpoint protection can make security controls on connected networks unnecessary.

While this may not eliminate the need for encryption, it will protect sensitive data and applications. Without a single security control, layer 1 protection becomes increasingly tricky.

We can better protect our resources by encrypting control, management, and user traffic. This makes it nearly impossible for hackers to break into the system, greatly reducing the chances of a successful cyber attack. As businesses become more reliant on data and connectivity, robust security solutions will only become more apparent.

Open Optical Network

An open optical network is an optical network that uses standard, open interfaces to allow integration of equipment from different vendors. This provides more choice and flexibility for optical network components. Plus, it makes it easier to add new features and services as they become available.

Growth of Spectrum Services

As data traffic continues to grow, so does the need for higher bandwidth and capacity. Spectral services provide this by using spectrum to increase the capacity of existing fiber optic networks. These services are growing in popularity because they provide a cost-effective way to meet growing data demands.

More outdoor deployments

Outdoor deployments in street cabinets are becoming more common as the demand for higher bandwidth and capacity grows. Outdoor fiber can run directly to the customer location, providing a more direct connection and lower latency.

compact and modular

As optical networks continue to evolve, the need for smaller, more compact components becomes increasingly apparent. This is because space in a data center environment is often limited. Compact modular optics offer a space-saving approach while still delivering high performance.

The Future of Optical Networking

Intelligent Optical Network

Intelligent optical networks are optical networks that use artificial intelligence (AI) to optimize performance. Artificial intelligence can be used to automatically identify and correct problems in the network. This allows for a more efficient and reliable network.

Additionally, AI can be used to predict future traffic patterns and demands. This information can be used to provision capacity in advance, ensuring that the network can meet future demands.

Flexible grid architecture

Flexible mesh architectures are becoming more popular because they provide a way to increase the capacity of existing fibers. The flexible grid allows multiplexing of different wavelengths of light on a single fiber. This allows more data to be carried on each fiber, increasing network capacity.

On-demand wavelength division multiplexing

Wavelength division multiplexing is a technique that allows multiple wavelengths of light to be transmitted on a single fiber. On-demand WDM is a type of WDM that allows capacity to be provided on demand. This means that capacity can be added as needed without installing new fibre.

Optical Networking in an Increasingly Digital World

Optical networking has come a long way in its relatively short history. From humble beginnings, it is now an essential part of many large network infrastructures. It is a key pillar of the Internet, revolutionizing the way we communicate and ushering in an era of unprecedented technological advancement.

As trends such as 5G mature, it appears that optical networks are poised to continue to play an important role in our increasingly digitized world