What Is A Fibre-Optic Cable?

Date First Published: 8th June 2022

Topic: Computer Networking

Article Type: Computer Terms & Definitions

Subtopic: Data Transmission Technologies

Difficulty Level: 5/10

Learn more about what a fibre-optic cable is in this article.

A fibre-optic cable, also known as an optical-fibre cable, is a network cable that is made up of one or more thin strands of glass fibres, each only slightly thicker than a human hair, where light signals can be sent through with little loss of strength. They are inside an insulated casing and carry communication signals using pulses of light that are generated by light-emitting diodes or small lasers. On the receiving end of the fibre-optic transmission, the light pulses are translated into binary values, which are what computers are able to understand.

Types Of Fibre-Optic Cables

• FTTP (Fibre To The Premises) - One of the fastest types of broadband available, since all of the cables are fibre-optic and are directly connected to a home or office. However, it is only available in a limited area as it requires a company to directly connect a fibre-optic cable to a home or office.
• FTTC (Fibre To The Cabinet) - A broadband technology that involves running fibre-optic cables from the distribution point or telephone exchange to the street cabinets and then copper cables to a home or office. It has a slower speed than FTTP, since FTTC does not use fibre all the way.
• FTTB (Fibre To The Building/Business/Block) - The same as FTTP.
• Direct fibre - Fibre that runs from the central connection point to the home or office. Although it is expensive, it provides the highest amount of bandwidth.
• Shared fibre - As the fibre runs to the premises of nearby customers, it splits up into other optical fibres for those users.

Uses Of Fibre-Optic Cables

Due to their higher bandwidth and capability to transmit data over longer distances, fibre-optic cables are often used as internet, cable television, and telephone cables as well as a larger part of the internet backbone. They are much faster than copper cables because copper uses electrons for data transmission, whilst fibre is lighter and uses photons. Because light is faster than electrical pulses, fibre is capable of providing much higher bandwidth and data transfer rates. Fibre-optic cables actually provide the fastest data transfer rates of any data transmission medium.

Advantages and Disadvantages Of Fibre-Optic Cables

• They provide high bandwidth and data transfer rate - Since they transmit data through light waves, they can transmit information at the speed of light, making them the fastest data transmission medium.
• Since the data is transmitted through light rays, there are no risks of electrical or electromagnetic interference.
• They allow for a much longer cable length than copper twisted-pair cables.
• They are lightweight and small, saving space.

• They are more expensive to install than other data transmission mediums due to special test equipment being required. The costs of producing fibre-optic cabling are higher than copper.
• They are fragile and more vulnerable to damage. If they are twisted or bent too much, they will break and stop working.
• They are difficult to splice. Fibre-optic cable splicing is the joining of two fibre-optic cables.