OM1 Fibre Cable – A Sneak-Peek into the OM1 Secrets you need!

Share post

The first thing that we need to know about OM1 Fibre Cable is that the “OM” prefix stands for Optical Multimode.The variation in cable types we all see on a day to day basis seems ever expanding; for example, Telephone Wires and Copper Cable. However, a cable type that many seem to misunderstand is Fibre Optic Cable.

OM1 Cable is one of five OM Fibre Cable types described by the Telecommunication Industry Association.

These standards define the guaranteed performance of various cables.

Multimode fibre has light travelling in the core in many rays, called modes of light.

An OM1 Duplex Fibre Patch cable typically comes with an orange outer jacket to allow you for easier identification by colour. The other Multimode Fiber Optic Cable types also have designated standard colours; being Aqua for OM3, Erika Violet for OM4 and Lime Green for OM5.




However, with Tight Buffer Indoor Outdoor Fibre Optic Cable being black, and Loose Tube Cable being a blue fibre optic cable you need to reference markings on the cable to identify the fibre type. The individual fibers within either of these cable constructions will not assist in the identification process either.


L-Series Loose Tube Fibre Optic Cable


Should there be no markings on the cable at all you will need to rely on good old visual inspection to identify the Optic Cable. This is made easier because the core size of OM1 Optic Cables is 62.5 microns; whilst the OM3 and OM4 core size measures in at 50. You will be able to see the larger core size easily using the Yamasaki V5000-Wifi Microscope.


Advantages of the larger core size in an OM1 Fibre Cable.

– The larger core size of the OM1 cable enables a greater angle for accepting light when compared to Singlemode cable.

– It Simplifies connections and increases the bend resistance of the cable.

– It allows the use of LED’s instead of VCSEL’s light sources, cutting costs dramatically.



What is the disadvantage of using an LED light source in an OM1 Fibre Cable?

There is a disadvantage to the use of LED light sources.

Mainly the LED’s inability to rapidly switch on and off, which severely limits the bandwidth of the Fibre Optic link.

OM1 Fibre Cable only supports 10Gb Ethernet in Short-Haul Networks, Local Area Networks and Private Networks up to 33 Metres. OM1 is therefore most commonly used for 100 Megabit Ethernet applications in which it can travel up to 2km. Unlike single mode fibre, which is a type of fibre designed for high speed data transmission and much longer cable lengths.
Another thing to note is that OM1 cable has been manufactured with a maximum attenuation value of 3.5 decibels per km at the 850-nanometer wavelength and 1.5 decibels per km at the 1300 nanometer wavelength.


Why is OM1 Cable on the decline?

Since the introduction of the other multi mode cables, OM1 Cable has slowly declined in popularity.

This is due to the lack of upgradeability of the fibre OM1.

OM1 fibre cable types simply cannot keep up with the demand, which results in severe limitations to a network.



With legacy installations of OM1 fibre link cable to Ethernet in abundance, the need for OM1 Optical Cable will remain. Fibre Optic installers are now, however, opting for the other OM cable standards when it comes time to upgrade the network.

The other OM Fibre Cable are more advanced types of fibre optic network cable, offering significantly improved performance such as higher speed, greater bandwidth and long distances of up to 150 meters for 100G thus allowing the installer to future proof the network.