When you open this article to browse, you may be using optical fiber broadband to carry WIFI signals to continuously transmit image and text information to your mobile phone, or you may be using 5G mobile signals to upload and download data through the signal tower, and the optical fiber that plays an important role in this is what we have heard about daily. Why did the data communication company of China Mobile Unicom begin to remove the original telephone line broadband from the past few years, and instead popularize the construction of optical fiber? To be blunt, of course, it is because the network speed will become faster and the signal will become stronger! Then why does it make the network speed faster and the signal stronger?

First of all, the optical transmission energy fiber transmits data through "total reflection of light". We are most familiar with reflection. When light shines on a plane or surface with low surface roughness, it will change the transmission path, such as when light shines on a mirror. Similarly, when light shines into the optical waveguide at a specified angle, regular reflection will occur. Because this reflection occurs in a closed optical waveguide, no light will leak or be absorbed. This is the total reflection of light.

It is not easy to achieve total reflection of light. Although we have achieved breakthrough results so far, there is still room for progress in light transmission. The optical fiber structure is hollow, and the material of the transmission channel is mostly SiO2 (silicon dioxide - the main component of glass), but also plastic. There is a layer of material outside the channel to prevent light from escaping. Such optical fiber channel has a very low refractive index, This makes the signal transmission weaken more slowly, that is, the transmission distance is longer.

Although the refractive index of optical fiber is extremely low, no product can be so perfect, and it is bound to be weak. Therefore, it is necessary to build repeaters and amplifiers in the optical fiber system. The repeater is used for optical fiber transmission signal attenuation to a certain extent, but it can not be weakened to no extent. The role of the repeater is mainly to convert the weakened light into electrical signals and then into optical signals. Amplifiers have similar functions, both of which are used to make signals travel farther.

Optical fiber has the advantages of price and weight. The cable made of optical fiber is usually integrated. Hundreds of optical fibers are bundled together, and each optical fiber can independently transmit massive data. Therefore, optical fiber has huge advantages.

The application range of optical fiber is extremely wide, not only for data transmission, but also for medical treatment, information processing, energy transmission and image transmission, telemetering and remote control, lighting and other aspects.