In the following days, the company went out to dig the optical cable trench every day, and set off and returned according to the schedule of optical cable construction. Pen | fun | pavilion www. ｂｉｑｕｇｅ。 ｉｎｆｏ

However, due to the influence of various geological conditions, the progress of the construction has been affected, and the construction period has been delayed again and again. The work that was originally planned to be four days has been done for ten days, and it has not yet been completed.

The veterans, day by day, are counting down the days of leaving.

It doesn't matter to the recruits, they have three years left anyway, and there is no expectation of that.

On the eleventh day, the trench was almost finished, and the rest of the work was to lay the cable.

Today, after getting up in the morning and having breakfast, the company came to the place where the fiber optic cable trench was dug on the first day.

The company commander said: "Today, we started laying fiber optic cables.

According to the technical requirements, the bottom of the ditch should be covered with 30 centimeters of sand, and then, the optical cable should be lowered to the ditch and then buried with fine soil.

After the entire cable trench is filled, a trapezoidal soil about 20 cm high should be raised on top to prevent the ground from becoming concave after the backfill soil becomes solid after rain. ”

After the fiber optic cable was brought by truck in the regiment, the fighters began to lay it.

We first unload the fiber optic cable from the car and then load it on the winch.

Then, starting from the beginning, everyone dragged the optical cable, walked forward along the edge of the optical cable ditch, and when a person in front walked out about eight meters away, another person came up behind him, carrying the optical cable on his shoulders and walking forward.

In this way, fifty people were able to lay four hundred meters, and then the next company would move forward in relay.

According to the technicians, each cable is about one kilometer long, and the cooperation of two companies can just finish laying a fiber optic cable.

After a plate of optical cable is fully opened, everyone shouts a password again, puts the optical cable into the optical cable trench that has been paved with fine soil, and then backfills the fine soil with a thickness of 20 centimeters, and then backfills all the soil taken out when digging the trench, and the excess soil is ridged above the optical ditch.

Anyway, laying fiber optic cables and backfilling the trench is much easier than excavation.

Guiding the missile company was a staff officer of the communications department of the military district, surnamed Gao, who was not yet 30 years old and was also a lieutenant.

After half a day's work, everyone got acquainted.

At this time, Yang Hua, a soldier of the third squad, asked Staff Officer Gao a question that he had been puzzled about for a long time.

"Senior Staff Officer, I see that this fiber optic cable is only finger thick, and it is not much thicker than a wire.

So how does it work, and why does it have such a strong communication capability? ”

Due to boredom at work, Senior Staff Officer and everyone worked while doing a popular science for everyone:

"Optical fiber communication, also known as optical fiber communication.

Optical fiber communication is a communication mode that uses light as the information carrier and optical fiber as the transmission medium, which first converts the electrical signal into 6 optical signals, and then transmits the optical signal through the optical fiber, which belongs to a kind of wired communication. The light can be modulated to carry information.

Since the 1980s, fiber optic communication systems have revolutionized the telecommunications industry and have played a very important role in the digital age.

Optical fiber communication has the advantages of large transmission capacity and strong confidentiality. Fiber optic communication is now the dominant method of wired communication today.

The most basic optical fiber communication system consists of an optical transmitter, an optical receiver, an optical fiber line, a repeater, and a passive component.

Among them, the optical transmitter is responsible for converting the signal into an optical signal suitable for transmission on the optical fiber, the optical fiber line is responsible for transmitting the signal, and the optical receiver is responsible for receiving the optical signal, extracting information from it, and then converting it into an electrical signal, and finally obtaining the corresponding voice, image, data and other information.

Optical transmitter ---- optical transceiver composed of a light source, a driver and a modulator to realize electrical/optical conversion. Its function is to modulate the light wave emitted by the light source from the electrical signal from the electrical terminal to become a dimmed light wave, and then couple the adjusted optical signal to the optical fiber or optical cable for transmission.

Optical receiver ---- optical transceiver composed of an optical detector and an optical amplifier to realize optical/electrical conversion. Its function is to convert the optical signal transmitted by the optical fiber or optical cable into an electrical signal through the optical detector, and then amplify the weak electrical signal to a sufficient level through the amplification circuit and send it to the electrical end of the receiving end to draw it.

The function of the optical fiber line ---- is to couple the dimmed signal sent by the sender to the optical detector at the receiving end after long-distance transmission by the optical fiber or optical cable, so as to complete the task of transmitting information.

The fiber optic cables we are laying now are actually fiber optic lines.

The repeater ---- consists of a light detector, a light source, and a decision regeneration circuit. It serves two purposes: one is to compensate for the attenuation of optical signals when they are transmitted in optical fibers; The other is the near-administrative nature of the pulses with waveform distortion.

Passive components ---- including optical fiber connectors, couplers, etc., to complete the connection between optical fibers, optical fibers and optical transceivers, and coupling.

The principle of optical fiber communication is: at the sending end, the transmitted information, such as voice, should first be turned into an electrical signal, and then modulated to the laser beam emitted by the laser, so that the intensity of the light changes with the amplitude of the electrical signal, and is transmitted through the principle of total reflection of light through the optical fiber; At the receiving end, the detector receives the optical signal and converts it into an electrical signal, which is demodulated and restored to the original information.

Optical communication uses the principle of total reflection, when the injection angle of light meets certain conditions, the light can form total reflection in the optical fiber, so as to achieve the purpose of long-distance transmission. The light-guiding properties of optical fibers are based on the total reflection of light rays at the core and cladding interface, which limits the transmission of light in the core. There are two types of rays in an optical fiber, namely meridian rays and oblique rays, meridian rays are rays that are located on the meridian plane, while oblique rays are rays that are rays that are transmitted without passing through the axis of the fiber.

After a while, you can see the core and cladding in the middle of the optical cable, as well as the outer wrapper. ”

"Oh, that's how it works?" Yang Hua nodded as if he didn't understand, imagining the principle of optical fiber communication.

"That's right! Nowadays, optical fiber can be used in a wide range of applications. However, the means of communication of our troops are too backward, and there are only three communication lines between the entire provincial capital and Bincheng, and if the lines are occupied at the same time, other telephones will not be able to be connected at all.

However, if the fiber optic cable is laid, it will be greatly improved.

Despite such a thin fiber optic cable, it can connect hundreds of phones at the same time, and the phones will not interfere with each other. Staff Officer Gao explained further.

"Huh? So amazing? Yang Hua stared at the optical cable line in his hand, feeling a little incredible, "It seems that the function of this little thing is really powerful!" ”