Is fiber optics afraid of water? Come to see the analysis of a god

Optical fiber is short for optical fiber, is a very widely used network transmission medium. Through the data to be transmitted by the electrical signal is converted into an optical signal for transmission of a communication method. The propagation principle of optical fiber is "total reflection of light".

In the actual application of integrated wiring, we can put the optical fiber into the water, it seems that there have been doubts. Some people think that the fiber is made of glass or plastic fiber, that can directly contact the water. In fact, the correct conclusion should be: the fiber is afraid of water.

Although we know a lot of cabling projects in the fiber optic cable can cross rivers and streams, in fact, we see the fiber optic cable, because the fiber optic cable has been in the outer layer of the optical fiber to do adequate waterproofing measures, to maintain a decade or even decades without problems.

We have two requirements for the protection of optical fiber, first, less external forces; second, the fiber to do a good job of waterproofing.

You can see all the fiber optic cables, were made plastic protective layer and metal protective layer, plus a layer of water-blocking layer, and then the optical fiber and grease stick together.

If the fiber optic cable in the water moisture, it will affect the normal transmission of communications, so that the fiber loss increases, but also corrosion of the outer components of the cable, reducing the strength of the cable; on the other hand, the cable into the water, the cold will be formed into ice, which may lead to the pressure of the fiber.

So normal fiber optic cables are filled with grease, just to prevent water from entering.

So we only know that the fiber is afraid of water, but can not get the theoretical basis, some time ago in the network to see a god's analysis is as follows:

If you want to argue why the fiber is afraid of water, fiber optic components are mainly SiO4, the composition of the form of silicon and oxygen tetrahedral interconnections, oxygen atoms in the form of bridging the presence of oxygen.

If you encounter water (H2O), the surface of the fiber adsorption will gradually hydrolysis reaction occurs, so the silicon oxygen bond will be broken, it will cause the fiber to break. This really explains from the source why the fiber is afraid of water!

In fact, fiber optic cables in normal circumstances, waterproof measures to do a better job, but we are in the fiber optic fusion splicing, connector box sealing, bare wire exposure to pay extra attention to, once the water will lead to a sharp decline in the life of the fiber or even direct fiber breakage.