A Beginner’s Guide to Fiber Optic Terminologies

A Beginner’s Guide to Fiber Optic Terminologies

Every expert was once a beginner. Who’s to say you should know everything overnight? So, let’s start small. We start off with the very basic terms used in the field of fiber optics, because how can you understand a discussion when you don’t what they’re talking about? The most important thing every technician or employee should know in fiber optics are the basic terms encountered not only in the internal environment but also when you are working in the field. Here are those important terms to understand in becoming productive and efficient fiber infrastructure professional:

Channel or link loss

The total path loss or attenuation between the transmitter and receiver is the sum of various loss mechanisms: scattering, microbending and macrobending and interconnection is called the channel or link loss. It may cause to limit the numbers of connections allowed as well as the maximum system length.


Rayleigh scattering results from variations in density and composition of the glass that also triggers the loss in intrinsic fibers.

Microbends and Macrobends

Light ray striking the fiber core-cladding interface at an extensive angle, allowing it to escape and increase loss is caused by Microbends. Microbends is defined as the deflection of the optical fiber axis. While on the other hand, Macrobends is bend or loop in the fiber that causes the power to be lost from the core and inducing additional loss.

Interconnection loss

Splices and connectors that is connected to interconnection loss can be divided into intrinsic and extrinsic. Axial, angular and transverse misalignment of the fiber cores may result to connection loss.

Intersymbolic Interference(ISI)

As pulse of light spread, it travels the length of the fiber. Overlapping of pulses may occur that can sometimes result to intersymbolic interference. If there is lesser intersymbolic interference occur there would be greater data transmission. Dispersion is the major cause of intersymbolic interference.

Chromatic dispersion

The tendency for different wavelengths to travel at different speeds in a fiber is called the chromatic dispersion.  If operated at wavelengths where chromatic dispersion is high, optical pulses tend to broaden as a function of time or distance and cause intersymbol interference. Although multimode fiber exhibits relatively high chromatic dispersion at the 850 nm wavelength, the use of controlled launch lasers (VCSELs) in gigabit networks and the distances in the LAN minimize the effects.

Modal dispersion

This kind of dispersion often occur in multimode fiber system that exist because of different light rays (modes) that have different optical path length along the fiber which means those light rays enters at the same time will not arrive at the same time.

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