What are optical fibres?
Over the last 20 years fibre optic technology have transformed the long distance telephone industry.
Optical fibres is a medium and technology that uses glass or plastic fibres to transmit data in light or infrared signals (heat) over long distances by reflecting (bouncing repeatedly) off the glass or plastic walls. Optical fibres are able to transmit data without any significant loss of energy over long distances at the speed of light (300 000 km/sec)
Optical fibres are arranged in bundles called optical cables. A fibre optic cable consists of 100 or more thin strands of high quality glass coated in two layers of plastic. The glass is very pure that even from kilometres away, it is still visibly clear, with no impurities. Each thread is less than a tenth thick as human hair.
Digital information such as computer data and up to 10 million telephone calls can be converted into visible light signals or infrared signals. Optic fibres can carry information between two places using optical (light-based) technology, with up to 10 million telephone calls.
Today more than 80 percent of the world's long-distance traffic is carried over optical fibre cables.
Optical fibres is a medium and technology that uses glass or plastic fibres to transmit data in light or infrared signals (heat) over long distances by reflecting (bouncing repeatedly) off the glass or plastic walls. Optical fibres are able to transmit data without any significant loss of energy over long distances at the speed of light (300 000 km/sec)
Optical fibres are arranged in bundles called optical cables. A fibre optic cable consists of 100 or more thin strands of high quality glass coated in two layers of plastic. The glass is very pure that even from kilometres away, it is still visibly clear, with no impurities. Each thread is less than a tenth thick as human hair.
Digital information such as computer data and up to 10 million telephone calls can be converted into visible light signals or infrared signals. Optic fibres can carry information between two places using optical (light-based) technology, with up to 10 million telephone calls.
Today more than 80 percent of the world's long-distance traffic is carried over optical fibre cables.
Types of optical fibres
The simplest type of optical fibre is called single-mode. It has a very thin core, about 5-10 microns (millionths of a metre) in diameter. They transmit infrared laser light (wavelength – 1300 to 1550nm). In a single-mode fibre, all signals travel straight down the middle without bouncing off the edges (red line in diagram). Cable TV, Internet, and telephone signals are carried by single-mode fibres which is wrapped together into one huge optical bundle, and can send information of up 100km.
Another type of fibre-optic cable is called multi-mode. Each optical fibre in a multi-mode cable is about 10 times bigger than one in a single-mode cable. This means light beams can travel through the core by following a variety of modes, unlike a single-mode. They transmit infrared light (wavelength – 850 to 1300nm). Multi-mode cables can send information only over short distances. They are used to link computer networks together.
Optical fibres that are made out of plastic have larger cores (1mm in diameter) and transmit visible red light (wavelength – 650nm
Another type of fibre-optic cable is called multi-mode. Each optical fibre in a multi-mode cable is about 10 times bigger than one in a single-mode cable. This means light beams can travel through the core by following a variety of modes, unlike a single-mode. They transmit infrared light (wavelength – 850 to 1300nm). Multi-mode cables can send information only over short distances. They are used to link computer networks together.
Optical fibres that are made out of plastic have larger cores (1mm in diameter) and transmit visible red light (wavelength – 650nm
The above video includes the inside of a fibre optic cable, stripped of its protective outer jacket. The cable is around 3 metres long.