What Is Fiber Optic Cable and How Does It Work?

What Is Fibre Optic Cable and How Does It Work

“Fiber Optics” is one of the most used terms when it comes to information technology and the transmission of data. However, only a few of us really understand how the technology actually works. If you have been asking yourself: “What Is fiber Optic Cable, and How Does It Work?” then please read on as we will give you a better understanding of both hardware and the technology.

What Is Fiber Optic Cable?

Simply put, optical fibers are long, thin strands of drawn glass with a diameter of less than a human hair. These strands are then bundled together in what is called a fiber optic cable.

Fiber optic technology was originally developed in the 1950s to create endoscopes, medical instruments used to examine the inside of a human patient without having to perform surgery to do so. In the 1960s, the technology was adapted by telephone engineers to send and receive telephone calls at the speed of light. To illustrate, this speed is almost 300,000 kilometers per second in a vacuum, but within a cable, this slows down to about two-thirds of this speed.

So, the main applications of fiber optic technology are signal transmissions and communication, be it data, video or audio. You can find fiber optic technology in computer networking, medical scanning, broadcasting, military equipment and more, and its use is far more widespread than many people think.

How Does Fiber Optic Cable Work?

A fiber optic cable consists of two basic components, the core and the cladding. Basically, light travels down a fiber optic cable, bouncing off its walls as it goes. The core, which is the main part in the center, is the part that the light travels through. Now you might expect that when a beam of light is traveling down a clear glass pipe, the photons (particles of light) will escape along the way. The phenomenon preventing this is called total internal reflection. If light hits the glass at a very shallow angle (i.e. less than 42 degrees), it will reflect back in as if hitting a mirror.

The cladding is another layer of glass that is wrapped around the core. Because it is made from a different type of glass compared to the core, it also keeps the light signals inside the core.

Now a cable can contain anywhere from two to several hundred of these strands, with each strand capable of carrying about 25,000 phone calls.

So how do fiber optics transmit data? The secret is a series of light pulses, which contain the converted electrical information from a computer. These light beams travel through the fiber optic cables to the destination, where a photoelectric cell turns the pulses of light back into electrical information that the computer can then process. 

There are three main advantages of fiber optic cable technology over the old technology using copper cables:

  • Less signal and, with that, data loss: The high efficiency of fiber optic cables allows information to travel about ten times further before it will need amplification. This means that fiber networks are simpler and cheaper to operate and maintain.
  • No interference: Where copper cables are susceptible to electromagnetic interference (commonly referred to as “crosstalk”), optical fibers are not affected by it, so information is being transmitted more reliably and with better signal quality.
  • Higher bandwidth: Due to the advanced technology, fiber optic cables are capable of carrying far more data than copper cables of the same diameter.

Also Read: Top 5 Benefits of Custom Cable Assemblies & Its Application

Different Types of Fiber Optic Cables

There are several different types of fiber optic cables. The two most used types are single- and multi-mode fibers. A mode is a path that the light beam follows down the strand.

The simplest type of optical fiber is called single mode. It consists of a very thin core in which all signals travel straight down the center without any bouncing. Single-mode fibers are often used for cable TV, telephone signals and the internet and are wrapped together in a giant bundle. 

The other main type is called multi-mode. Here the optical fiber is about ten times bigger than the one in a single-mode cable. This allows light beams to travel along multiple paths, meaning multiple modes. These kinds of cables can only send information over comparatively short distances and, among other uses, are often used to link different computer networks together.

What is fiber Optic Cable Used For?

Fiber optic cables have four main uses:

Computer Networks

Most people know about fiber optic technology being used for the internet, having replaced copper cables as the main connection for their surfing needs. It has brought higher bandwidths, less signal loss and far higher speeds together and forms the new standard, linking together computers, cities, countries, and even continents, with fiber optic cables running along the bottom of the oceans, bringing the world together.

The advanced technology, with the speed and bandwidth exponentially increasing, also gave birth to things such as cloud computing, where users store and process their data in the “cloud”, accessing it remotely instead of having it saved on their computer. It also has paved the way for streaming music, video and movies online.

fiber cables also have replaced the old copper Ethernet cables in private computer networks, increasing efficiency and speed.


Similar to the introduction of broadband fiber optic internet, the radio and TV industry also has greatly benefited from fiber optic networks. Replacing coaxial cables, which were copper cables wrapped in a metal sheath to avoid crosstalk interference, cable TV networks introduced fiber optic cables to carry data for hundreds of TV channels in one single optical fiber cable. And the far higher capacity is not the only advantage because they also suffer from less interference leading to a better picture and sound quality, and are more cost-effective as they do not require as much amplification to travel over long distances. A lot of TV stations are now offering their own streaming services with TV programs and movies either as an addition to their regular broadcasts or on demand.


Originally optic fibers were developed for endoscopes, helping medical professionals to examine the inside of patients without having to perform invasive surgery. While gastroscopes are still as relevant as ever, fiber optics have allowed for new forms of medical scanning and diagnosis.

Fiber optic cables are now also used for other applications in patients’ bodies, such as gathering information through the reaction of the body to the light signals in the way it alters them. The instruments attached to these fibers can record the patient’s temperature, blood pressure, cell pH and many other things, which is an exciting development in how medicine is performed.

Military Equipment

It may come as a surprise that the military also is a heavy user of fiber optics, but its advantages are clear. They are inexpensive, thin, lightweight, have a very high capacity and are also extremely secure as they are robust against attacks and cannot be disrupted by electromagnetic interference. The lighter weight and smaller size also are an advantage within vehicles, such as tanks, helicopters or airplanes, where they also improve security and reliability.

So as you can see, fiber optic cables have a lot of different uses and have revolutionized the way data is transferred. Tevelec is a leading wire and cables distributor that offers different fiber optic cables to help you bring your home or office up to date and enjoy the speed, bandwidth and security of a fiber optic network. 

Contact Tevelec today at +1 877-838-3532 to find out how we can help you with your fiber optic cable needs!

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