The cable classified as single mode fibre transmits signals over long distances by carrying light. A single fibre strand sends a ray of light (mode) down a line. Compared to multimode fibres, the integrity of the light pulses travelling through single-mode cable can be maintained over longer distance transmissions, up to 100km. Single-mode fibre optic cables are utilised in higher bandwidth applications. They have a small core size of 9 microns. The single-mode fibres in telecommunication cables operate at 1310 or 1550 nm wavelength. OS1 and OS2 are the specifications for single mode optical fibre cable. Maximum bandwidths and corresponding distances for singlemode are: 10 km for 10-gigabit Ethernet at 1310nm and 80-100km at 1550nm. 10km for 1000Base-T at 1310nm, and 80-100km at 1550nm.

OS1 and OS2 Single-mode Cable Specifications

Categories of OS1 and OS2 single-mode cable have specific guidelines. OS1 is constructed for indoor use. The OS2 category is also suited for the outdoors. Single mode fibre is recommended over multimode fibre when planning for Gigabit Ethernet. The multiple light modes found in multimode fibre can create distortion and quality degradation on the receiving end of lengthy data transmission. University and industrial LANs frequently feature single mode fibre optic systems.

Fibre Identification Sheet

Don’t know how to identify fibre connections? Find out more here.

Comparing a Singlemode Fibre System to Multimode

The core of both multimode and single-mode fibre is covered in a material called cladding. When comparing a single mode fibre system to multimode, the single-mode cable has a smaller core and cladding diameter of 9/125 micron. Higher transmission rates are achieved with single-mode systems, and signals travel successfully over longer distances. Higher grade electronic equipment and fibre optic accessories are usually required to support single-mode fibre cable installations.

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