Fibre Optic Guide

This guide contains an overview of fibre optic technologies. Any further assistance needed can be found by calling our sales team.

Keywords: Broadcast, Fiber Optic, Patching

Multimode Fibre Vs Singlemode Fibre

Multimode Fibre Vs Singlemode Fibre

Multimode fibre has a significantly larger core (approx.50µm) compared to single mode (approx.9µm), this allows for a larger number of simultaneous modes to propagate through the fibre. Modes result from the fact that light can only propagate through the fibre at discrete angles and thus with a larger core more angles are 'acceptable', because multiple paths are being taken by the same signal, and all the paths have a fractionally different distance depending on the angle of reflection, signal dispersion becomes a serious problem over longer distances.

fiber Graded index refers to a type of fibre optic cable whose refractive index decreases relative to the distance from the centre of the core, the increased refraction in towards the center of the fibre slows the speed of some of the light rays, allowing all routes to reach the receiver at approximately the same time, significantly reducing dispersion.

The larger core of multimode fibre reduces its requirement on the wavelength transmitted being consistent so cheaper transmission hardware is needed, even simple LED setups will propagate moderately well at lower data rates, this significantly reduces roll-out and maintained costs compared to singlemode fibre.

Singlemode fibre has a higher potential data rate than multimode fibre because of its ability to retain the fidelity of the lightwave transmitted. The overall attenuation per meter is significantly lower in singlemode fibre but the smaller core diameter makes coupling more difficult and more expensive hardware needs to be used.

Loose Tube vs Tight Buffered

Loose tube cables are intended for harsh environment conditions including outdoors. They protect there Fiber core, cladding and Coating by enclosing everything within a rigid tube.

Most loose tube cables also contain a water resistant Gel around the fiber, making the cables ideal for high humidity environments, where condensation may otherwise be problematic.

Tight buffered cables are intended for indoor applications. They are more hardwareing than loose-tube cable, as such they are well suited for long indoor LAN connections, burial or complete even submersion in water. Tight buffered cables have a special two-layer coating. The first layer is plastic, the other a waterproof acrylate.

Color coding Convention

Jacket Colour







10 gig multi-mode


Polarizing fibre

Connector Colour



Physical Contact Polished Core


Angled Polished Core (8°)


Physical Contact Polished Core


Physical Contact Polished Core


Physical Contact Polished Core


Dangerously High Optical Power (e.g. Optical Amplifier Pumps)

Size Guide


Core Diameter (µm) / Clading Diameter (µm)


An Argosy Fibre Assembly

Singlemode Fibre On A wooden drum

Author: DanielSaunders - Website and Catalogue Administrator at Argosy

Contributor: Neil Burman - Technical Support Supervisor at Argosy

Editor: DanielSaunders - Website and Catalogue Administrator at Argosy

Version: 1.0

Date Added: 2013-07-02

Genre: Non-Fiction, Broadcast Engineering

Expected Reader Proficiency: Beginner

Language: en-GB