I don’t know if you have ever seen such warning signs or road posts. They often have serious warnings written on them: "It is strictly prohibited to dig national defense optical cables", "Sentences for damage to national defense optical cables", "One million yuan will be lost if the optical cable is broken"...
Warning posts on the roadside
However, such straightforward words still cannot stop some people from "committing crimes against the wind". On November 6, 2020, the owner of a liquefied gas station insisted on construction without notifying maintenance personnel even though he knew there was a national defense optical cable nearby. As a result, he dug out a secondary trunk national defense optical cable, interrupting communications for more than 5 hours. , the direct economic loss was 113,600.
The optical cable that was violently dug up
What is even more ridiculous is that just 11 days later, he "confidently" arranged the excavator operation again, and ended up digging out a first-class trunk line defense optical cable, this time interrupting 3 and a half hours of communication, a loss of 155,700.
The optical cable after the break
Later, even though he had an excellent attitude of admitting his mistake and made compensation, the boss was sentenced to to to one year in prison and one year of probation. There are many similar news, which may make people a little confused, what is optical cable used for? Why are the consequences of digging out so serious? How to repair it after it breaks?
The development history of optical cable
Although the optical cable looks thick on the outside, it is actually wrapped with one or more thin "optical fibers" .
Internal structure of optical cable
In the 1960s, the original communication technology could no longer meet people's needs, so scientists turned their attention to laser carriers. However, many subsequent experiments proved that transparent materials absorb a large amount of light and are not suitable for communication.
"Total reflection" of laser in transparent materials
Just when most people had given up, in July 1966, Chinese engineer Kao Kun published a paper. He believes that the main cause of loss caused by is the impure material, not the glass itself.
Unfortunately at that time, glass manufacturers were basically producing decorations and utensils, and no one was willing to try to make fiberglass . Fortunately, hard work paid off. In 1970, Corning Corporation of the United States produced the world's first "low-loss optical fiber." Later, with the rapid growth of optical fiber systems, many optical cables were also laid under the sea.
The "undersea optical cable" that connects the world
It can be said that the convenient communication of the entire world and people's happy surfing on the Internet are inseparable from Kao Kun's contribution. It is precisely because of this achievement that in 2009, Kao Kun won the " Nobel Prize in Physics ".
Gao Kun and his wife
The value of optical cables
Having said that, glass fiber itself is not worth much, but the function of optical fiber is to transmit information, which is worth too much money, not to mention it is a national defense optical cable related to military communications. Woolen cloth!
In addition, the repair of optical cable is also quite troublesome for . Imagine trying to reconnect optical fibers that are thinner than a human hair one by one. Would it be time-consuming?
An optical fiber as thin as a hair
Nowadays, the commonly used method is- spliced fiber . First, the outer skin must be removed to expose a section of the inner core; then it must be fixed and cleaned; next, it must be cut with a special cutter. The purpose of this step is to obtain two optical fibers with flat sections; Next, the processed glass fiber is put into the machine, and the high-voltage arc released will melt the cross section. At the same time, both ends of the machine are also advancing smoothly, and finally the two optical fibers are fused into one. Doesn’t this picture look quite decompressing~
Remove the skin
Cut the optical fiber
Put it into the "fiber melting machine"
The melting process of optical fiber
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