Fiber Optic, what it is and how it works

The fiber is interesting because it takes a very old concept that is the manipulation of light, is nothing more than that, the controlled manipulation of light. If we go back to history, the Egyptians themselves controlled the light through mirrors to illuminate inside the incredible pyramids ... Precursors of fiber optics?

Today the manipulation of light is controlled within a cable, with special terminations and on special plates that make transmission possible and that I will detail throughout this humble note.

By seeing in detail how fiber optics is composed, we will understand its advantages and disadvantages, as well as, we will have a global vision of this medium. This example is about a cable made up of many parts, you have to understand that there are many types of cables that adapt to different occasions (interior, exterior, etc.), but I took this as a reference because you can see in detail what elements can contain a cable. This will serve them because commonly in the fiber optic cable catalogs, it is specified what they are made of, therefore, knowing the components and for what they work, we will be able to choose the best cable for what we are assembling.

Structure of an optical fiber

1- Dielectric central element : this central element that is not available in all types of optical fiber, is a filament that does not conduct electricity (dielectric), which helps the consistency of the cable, among other things.

2- Moisture drainage thread : its purpose is for moisture to come out through it, leaving the rest of the filaments free of moisture.

3- Fibers : this is the most important part of the cable, since it is the medium through which the information is transmitted. It can be made of silicon (glass) or highly processed plastic. Here the physical phenomena of reflection and refraction occur. The purity of this material is what makes the difference to know if it is good to transmit or not. A simple impurity can deflect the light beam, causing it to be lost or not to reach its destination. As for the manufacturing process, it is very interesting and there are many videos and material on the network, but basically the strands (microns wide) are obtained by exposing glass tubes to extreme heat and through the dripping that occurs when melting, it is they get each one of them.

4- Loose Buffers : it is a small tube that covers the fiber and sometimes contains a gel that serves the same purpose, also making it a dark layer so that the light rays do not scatter out of the fiber.

5- Mylar tape : it is a thin polyester layer that many years ago was used to transmit programs to PC, but in this case it only fulfills the role of insulator.

6- Flameproof tape : it is a cover that serves to protect the cable from heat and flames.

7- Synthetic Kevlar threads: these threads help a lot to the consistency and protection of the cable, taking into account that Kevlar is a very good fire retardant, in addition to supporting the stretching of its threads how do fiber optics work.

8- Tear thread : they are threads that help the consistency of the cable.

9- Sheath : the upper layer of the cable that provides insulation and consistency to the set that has inside.

Now that we know how a cable is made up, let's see how it works. I am not going to detail the operation mathematically because it is not the idea, I am only going to talk about the two phenomena of optics that allow transmission and are the icing on the cake. Also on the network there is plenty of information to expand your knowledge.