Fibre optics are quite rapidly taking over as the most common means of communication signal transmission. Everyone is using fibre optic cabling even if they are unaware of it. These long strands of covered glass span great distances and are used by commercial business, governments, the military and many other industries for a great number of applications involving the transmission of voice, video and data.
What is fibre optic cabling?
A fibre optic cable incorporates highly flexible glass threads as thin as human hair, each of which is able to transmit messages modified into light waves. It may seem absurd to create cables out of glass, but each one is highly durable and coated in a protective cladding that not only binds the fibres together but also reflects light back into the core of the cable. A further protective layer is then placed on top.
The types of fibre optic cabling available
There are two main types of fibre optic cables: single mode and multimode.
Single-mode
Single mode cable has a single light path (or one to two glass fibres) with a diameter of 8.3-10 microns. With a narrow diameter, single mode cable is able to carry a higher bandwidth but requires a light source with a narrow spectral width. Thanks to its small core and single mode of transmission, there is no risk of overlapping light pulses, meaning it provides the least signal attenuation and the highest transmission speeds of any fibre optic cable type. It also means it can guarantee 50x more distance than multimode.
These require more expensive electronics which operate in the 1310 and 1550nm windows and are most often used outside between buildings, so typically longer distance LAN’s, Cable TV telephony applications.
Multi-mode
Multimode fibre cables are slightly larger in diameter than their single-mode counterparts, and have core diameters of either 50, 62.5, or 85 microns. This is because the core consists of numerous concentric layers of glass rather than one single light path. This type of cable is typically used to carry signals in short runs within buildings, and in particular in applications that require a wide range of wavelengths, such as telecommunication, scanning, imaging, and data processing systems. Although they can experience higher losses compared to single-mode, optical amplifiers can be used to boost the signals to the required power.
Multimode OM4 fibre optic cable is often used in data centres aiming to receive high speeds of 10G or even 100G and are ideal for Local Area Networks (LAN) backbones, Storage Area Networks (SAN), Data centres and central offices.