Single-mode Vs Multi-mode fibre

Single-mode vs Multi-mode fibre
Performance of fibre Andover
Single-mode vs Multi-mode fibre London

What is fibre Optic Cabling?

Fibre optics technology has revolutionized how we communicate. The ability to transmit large amounts of data with minimum loss is a huge advantage in today’s world. Fibre optic cabling is a type of cabling that uses optical fibres to carry signals. These signals can be in the form of data, voice, or video. Fibre optic cabling comes in two modes. In this article we will be discussing Single-mode vs Multi-mode Fibre, What are the differences?

Fibre optic cabling offers many advantages over traditional copper cabling.  These advantages include:

  • Fibre optic cabling can carry more data than traditional copper cabling.
  • Fibre optic cabling is less susceptible to interference than traditional copper cabling. This makes it a better choice for environments where there is a lot of electrical noise.
  • Fibre optic cabling is lighter and smaller than traditional copper cabling. As a result, it’s easier to install and takes up less space.
  • Fibre optic cabling is more durable than traditional copper cabling. It can withstand higher temperatures and is less likely to be damaged by corrosion.

Single-Mode Fibre

Single-mode fibre is designed for transmitting a single-mode of light. This is done with a laser from the transmitting device. The single-mode of light travels directly down the core with minimal reflection within. The inner core is smaller than its counterpart which is why it’s called 9/125. This means that the core is 9 microns in diameter while the cladding is 125 microns. The transmission properties reduce dispersion of light as it travels along the core, which results in less loss of the original signal. This makes single-mode fibre more suited for higher bandwidth requirements and longer transmission distance applications.

Single-mode cables are categorised into 2 sub sections, OS1 and OS2.

It’s important to understand the differences between OS1 and OS2 cables before deciding which one to use. In addition, knowing the right cable for the right job can make a big difference in terms of performance and reliability.

There are several key differences between OS1 and OS2 cables. OS1 cables are usually tight buffered and designed for internal use. OS2 cables are loose tube and better suited for external applications. Both have similar transmission characteristics, but OS2 cables have less attenuation and can transmit data over longer distances. As a result, this makes them a better choice for certain applications. Such as, 10GBE transmission. However, the overall cost of a single-mode system is typically higher than that of a multi-mode system. One potential downside is that OS2 cables can be more expensive to purchase, but they are the same cost to install.

Multimode Fibre

Multimode fibre is a type of fibre optic cable that can transmit multiple modes of light, all of which travel down the core at different wavelengths. The light source is usually an LED source. The light is much like shining a torch into the core. Because of this, multimode fibre has a greater modal dispersion (loss) than single-mode fibre. However, multimode fibre still has a shorter transmission distance capability than single-mode.

Multi-mode fibre comes in a few different categories, each with a different core size. The 50/125 and OM1 Legacy are two of the most common, while the OM4 and OM5 are the newest grades. They all have the same cladding, but the internal core size changes depending on the grade. As a result, this allows for a better ability to transmit greater bandwidth.

The 5 categories of multi -mode fibre are OM1, OM2, OM3, OM4, OM5. The higher grades can transmit the same speeds as the previous grade, but over longer distances.

Below is a chart comparing the different cables and their transmission capabilities

Single-mode vs Multi-mode Fibre Summary

Core sizes

Single-mode = 9/125 microns

Multi-mode =50/125 microns. OM1 category 62.5/125


Single-mode uses a singular mode of light which is transmitted via a laser light source

Multi mode uses various modes of light via a LED light source

Distance Limitations

Single-mode is generally used up to 2km and often beyond 10km

Multi-mode is restricted to 550m performance. It’s co0mmonly used internally or on small campus plots.

For further articles about fibre optic cables, please use the link below.

For our article on How fibre optic cables work, follow this link

Send us mail