How does fiber optic works?

Fiber optics might appear as a complex subject. Well, it actually is, but it can also be easily explained for the enthusiast. We developed this guide for those studying the basics of fiber optics, as well for those explaining to someone new in the field. 

The simple:

Fiber optics: technology that uses glass or plastic threads to transmit data.

These glass threads are no thicker than a single strand of hair with the capacity to transmit information up to 200,000 km per second.



How does the fiber work?

Fiber optics work thanks to the refractory and reflexive properties of light.

Refraction is the change of direction in which waves incur when going from one medium to another.

Reflection: it is also a change of wave direction but in this case towards the source.

Light pulses travel through the fiber’s core which is protected by a “wall” in order to avoid their loss and constant reflection.

The core and coating glasses have different compositions so that the coating has a lower refractive index and can trap the light beams which are transmitted with a certain inclination index.

A fiber optic cable consists of a single fiber or a group of them each surrounded by a coating, 

Fiber cables need three other components to operate: the light emitting source, a converter that transforms the light beams into electrical pulses and the connectors that are responsible for attaching the cables to these components.

For example, this is how the light would look inside a single-mode fiber cable


And the multimode fiber patch cable looks like this:


Types of fiber optics

There are two basic types of fiber optics: single mode and multimode.

Single-mode fiber:

The core of the single-mode fiber is small that allows only a ray of light to travel in a straight line through it.

The single-mode optical fiber has the denomination 9/125, which means that the radius of the diameter of the core the and the coating is 9 microns and 125 microns.

Used by telecommunication service providers, cable and television companies and large university campuses.

  • Telecommunication service providers
  • Cable and television companies
  • Large university campuses.

Multimode fiber

The core diameter allows multiple beams of light to propagate through the fiber.

The multimode fiber may be 50/125, which means that the radius of the diameter of the core and the coating is 50 microns to 125 microns.

Single-mode fiber is used for short-distance transmissions, such as local area networks (LAN) and the transmission of information in Data Processing Centers.


How to identify fiber types?

You can identify fibers thanks to a color code established by the Telecommunications Industry Association (TIA). Single-mode fiber cables should be yellow, multimode cables OM1 and OM2 must be orange and the multimode OM3 and OM4, blue.

Here's a quick look at our fiber optic color standards guide

January 11, 2017 by
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