How Fiber Optic Cables Work


Solid State Member
How do fiber optic cables work? Well I will tell you for all that are interested. Fiber optics, or optical fibers, are long, thin strands of very pure glass, as thin as human hair. They are arranged in bundles called optical cables which are used to transmit light signals, or digital information, over long distances.

If you were to look at a single optical fiber, magnified, you would see that it is made up of the following parts:

* Core: Thin glass center of the fiber where the light travels
* Cladding: Outer optical material which surrounds the core and reflects the light back into the core.
* Buffer coating: Plastic Coating that protects the fiber from moisture and damage.

Thousands of these optical fibers are arranged in bundles to make up optical cables. There are two types of optical fibers; Single-mode fibers, which have small cores and transmit infrared laser light and Multi-mode fibers, which have larger cores and transmit infrared light from light-emitting diodes (LEDs).


Golden Master
also, if i may add.

Fiber cables work on the principle of refraction.

when light goes from a less dense (core), to a more dense(cladding), that light bounces, like when u look at a straw in a glass of water. in effect, its almost like water (light) going through a garden hose (fiber).

The glass in fibers are so pure, that if you were to use the same glass in ur clear windows in the house or car, it would give horrible losses to the data/light and would be extremely in inefficient.

Ex. and inch thick pane of glass has the same amount of impurities as a fiber as long as a football field. on average.

Heres something to think of...

if fiber optics are so fast why arnt they EVERY were instead of like, Cat5 or Cat 6 wires?


the fibers limit of transfer rate is boundless....unlimited. BUT what limits it is the electronics that are on the transmitter and receiver end. The fiber only works as fast as the connected electronics can work.

And also Fiber based comm systems arnt as expensive as others make it out to