Single-mode and multi-mode fibre
Single-mode fibre optics have a small diameter core, which allows only one mode of light to propagate. Multi-mode optical fibres are about 10 times bigger than single-mode fibres.
Single-mode fibres have a very thin core, with a diameter of 8-10 microns for the optical signal to move through. The light signal follows the principal of total internal reflection, and passes through the fibre core throughout the fibre length at the speed of light. Due to lowered attenuation, the signal can travel faster and farther. A single-mode fibre cable is suited to long distace networks, such as from one city to another, one state to another, or even one continent to another.
Multi-mode optical fibres are about 10 times bigger than single-mode fibres. They allow light beams to travel in a variety of paths (hence the name multiple modes). Multi-mode fibre optic cables have a large core diameter to allow multiple modes of light. Due to multiple modes of light travelling within the fibre, dispersion and attenuation is higher than in single mode fibres. A multi-mode fibre cable is suitable for small distance applications such as local area networks, transmission from one complex to another, one machine to another, and for indoor use.
| Application | Single-mode fibres are meant for long distance data transmission networks (100 kms and above) due to their enormous bandwidth and low losses. They are generally used by telcos, CATV companies, railways, power grids and oil and gas companies. Multi-mode fibres are typically meant for short distances (maximum 2 kms) and are generally used in data and audio/video applications in local area networks. |
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| Characteristics | Large fibre counts with small cable diameter. These cables are highly adaptable to mass splicing and are suitable for installation in pipelines. |
| Applicable standards | IEC 60793, IEC 60794, Telcordia GR -20, TIA/EIA 598 |
| Product range | APAR offers single-mode optical fibre cables using G652D/G655 & G 657 fibres from 2F to 512 F, in armoured, unarmoured and aerial appliications. Multi-mode optical fibre cables using OM1/OM2/OM3 & OM4 fibres from 2F to 24F, in armoured, unarmoured and aerial applications. |
| Advantages | Single-mode fibre optic transmissions are faster than multi mode over long distances, because fewer switches or routers are needed mid span. They have virtually unlimited bandwidth, and are capable of transmitting data at up to 40 GB over hundreds of kilometers, with little integrity loss. Multi-mode cables are less expensive to install, operate, and maintain. Multi-mode cables have high speed and high bandwidth over short distances. They allow several mode optical signals to be transmitted at once. |
Published On: January 20, 2021