Understanding types of Fibre optic cable

Fibre optics, which is the science of light transmission through very fine glass or plastic fibers, continues to be used in more and more applications due to its inherent advantages over copper conductors. The purpose of this article is to provide the non-technical reader with an overview of these advantages, and the differences between multimode and single mode fiber optic cables.

Fiber Types

Fiber types can be single mode or multimode. Modes simply describe the distribution of light energy across the fiber. Light rays can travel through the wire as long as they hit the core-cladding interface at an angle less than that of the critical angle.

Multimode
Multimode cable has a large-diameter core that allows multiple pathways of light to propagate. It is most commonly available in two core sizes: 50-micron and 62.5-micron.

Multimode fiber optic cable can be used for most general data and voice fiber applications such as adding segments to an existing network, and in smaller applications such as alarm systems and bringing fiber to the desktop. Both multimode cable cores use either LED or laser light sources.

Multimode 50-micron cable is recommended for premise applications? (backbone, horizontal, and intrabuilding connections). It should be considered for any new construction and for installations because it provides longer link lengths and/or higher speeds, particularly in the 850-nm wavelength, than 62.5-micron cable does.

Multimode cable commonly has an orange or aqua jacket; single-mode has yellow. Other colours are available for various applications and for identification purposes.

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single-mode

Is a Single stand of glass fiber cable usually with a diameter (8–10-micron) glass core and through which only one modewill propagate typically 1310 or 1550nm. Because of this, the number of light reflections created as the light passes through the core decreases, lowering attenuation and creating the ability for the signal to travel further. With only a single wavelength of light passing through its core, single-mode cable realigns the light toward the center of the core instead of simply bouncing it off the edge of the core as multimode does.

Single-mode cable provides 50 times more distance than multimode cable does. Consequently, single-mode cable is typically used in high-bandwidth applications and in long-haul network connections spread out over extended areas, including cable television and campus backbone applications. Telcos use it for connections between switching offices. Single-mode cable also provides higher bandwidth, so you can use a pair of single-mode fiber strands full-duplex at more than twice the throughput of multimode fiber.