Fibre Optics Explained

Fibre Optics Data Cabling Explained

General Fibre Optic Cabling Terms & Definitions

Absorption: The amount of light lost in transmission through the optical
fibre over distance

Adaptor: Can be simplex or duplex, connecting two different optical fibre
connectors together

Attenuation: Measured as the amount of power lost in dB across a known
length of optical fibre

Attenuator: Reduces the amount of power in dB across between devices

Back Reflection: The amount of light reflected at the faces of two fibre
optic connectors in -dB

Bandwidth: The operating frequency achievable across a fibre optic link in
nM

Fibre Connector: The junction device between two optical fibre and/or device

Coupler: Can be simplex or duplex, connecting two similar types of connector

Crossed Cable: Provides ODD Polarity of the optical fibre link

Duplex Cable: Two separate optical fibres joined along the length with the
outer jacket material

Duplex Fibre Connector: Two fibre connectors joined together

Fusion Splice: The method of permanently connecting (glass fusion) two
separate optical fibres

Gelly Filled Cables: Silicon Gelly Filled fibre, used to prevent moisture
penetration

GBIC: Gigabit Interface Converter

Insertion Loss: The attenuation caused by the insertion of a device or cable


Loose Tube Cable: A hollow sleeve containing multiple single optical fibres

Loss Budget: The amount of power that can be lost in dB before connectivity
is lost

Low Smoke Zero Halogen: European Standard for Smoke Emission of Optical
Fibre

Jack: The female receptacle - usually found on equipment.

Mandrel: A fibre wrapping device used to cause attenuation within a fibre
cable.

Mechanical Splice: A mechanical means of connecting two fibres.

Multimode Fibre: A type of fibre optic cable where the core diameter is much
larger than the wavelength of light transmitted. Two common multimode fibre
types are 50/125 and 62.5/125.

Plenum Cable: American Standard for Smoke Emission of Optical fibre

Premise Distribution Riser: Indoor multiple 4 or more core tight buffered
optical fibre

Return Loss: Launched Power lost across the length of cable and returned.
Measured in +dB

Scattering: Internal glass characteristic such as glass molecules can cause
light dispersal

Simplex Cable: A single core fibre optic cable in multimode or single mode

Straight cable: Provides EVEN Polarity of the optical fibre link

Trunk cable: Cable constructed with more than four optical fibres

Tight Buffered Cable: Kevlar is used to protect the fibre and provide end to
end tensile strength

Single mode Fibre: A type of fibre with a small core that allows only one mode of
light to propagate.

Splice: The mechanical or welded together fusion of two optical fibres

Termination: The means to place an optical connector onto a fibre

Dispersion: Separation of a wavelength into spectral components with
different wave lengths.

Wavelength: The wavelength is the distance between repeating units of a wave
pattern in nM

Differential Mode Delay: When the multiple modes of light become
unsynchronised causing dispersion of the light due to molecular
interference, thus segregating the signal..

Dark Fibre: Fibre which has been laid but has not active optical fibre
device attached

Wavelength-division multiplexing (WDM): Multiplexes multiple carrier optical
signals across a single optical fibre link using different wavelengths and
colour spectrum light to carry multiple signals

Zip Cord: Another name for duplex fibre, can be separated to form two
simplex cables