Fiber Optics Network: We may come across the word fiber-optics when people speak about the telephone systems, cable TV systems or relating to the Internet.

1.1 What is Fiber-optics?

They are the strands, and the manufacturers made them with optically pure glass which is thin same as human hair. It will carry the digital information for the long distances. We can use it in the medical imaging and the mechanical engineering inspection.

Here is the information regarding how these glass strands which are tiny transmit light and how they are made.

1.2 Optical Cables

The correct definition of the fiber optics is that they are long and thin strands which are made up of very pure glass. Manufacturers will arrange them in the bundles, and we will call them as the Optical cables. We can use them to transmit the light signals throughout the long distances.

The parts of the Fiber Optics are:

Core: It is the thin glass, and it is present at the centre of the fiber, and from it, the light travels.

Cladding: The material that surrounds the core at the outside region reflects the light, and it will enter the core.

Buffer Coating:

It is the plastic coating which saves the fiber from getting damage and moisture.

They arranged the thousands of the optical fibers to form a bundle and places them in the optical cables. The cable’s outer covering will protect the bundles, and we will call it as the jacket.

There are two types of optical fibers. They are single-mode fibers and multi-mode fibers.

Single Mode Fibers:

It contains small cores whose diameter is about 3.5 x 10-4 inches or 9 microns. These cores can transmit the infrared laser light which has the wavelength of 1,300 to 1,550 nanometer.

Multi-mode Fibers:

It features the large cores, and their diameter is about 2.5 x 10-3inches or 62.5 microns. They can transmit the infrared light whose wavelength is about 850 to 1,300 nm, and they can pass through the light-emitting diodes.

1.3 Working of Optical Fiber: Fiber Optic Network

If we desire to make the flashlight beam to shine down a long and straight hallway, then it is enough if we point the beam straight down the hall. Then there will be no problem; the light travels in the straight line.

What happens if the hallway is in bend stage?

Then the solution for this places the mirror in the bend region. It will reflect the light beam.

What happens if the hallway has many bends?

If it is the condition, then we have to line the walls with mirrors, and we have to angle the beam. Then the light gets bounces from all the sides and travels along the hallway. It is the scenario which takes place in the fiber optics.

Total Internal Reflection:

People will call this principle of always bouncing from the cladding as the Total Internal Reflection. As the cladding did not observe the light, it can travel over the long distances.

Sometimes due to the presence of impurities, the light get degrades in the fiber.

The extent of degradation of the signal relies mainly on the glass purity, transmitted light wavelength (for example, 850 nm = 60 to 75 percent/km). Some optical fibers which are premium will produce the signal degradation less than 10 percent/km at 1,550 nm.

2.0 Fiber-Optic Relay System

How to use the Optical fibers in Communication Systems

If there are radio silence and two ships travelling on the stormy seas and they are trying to communicate then one ship pulls up than the other one.

Fiber Optic Network

The captain of one ship will send the message to the sailor and sailor will translate it into the Morse code. This code contains the dots and dashes, and he will send it to the other ship using the signal light.

The sailor on the other ship will decode the Morse code message into English, and he will send it to the captain.

Then imagine the same situation when the boats are on either side of the ocean. Here, they will communicate using the fiber-optic communication system (Fiber Optic Network).

Here are the components that are present in the fiber-optic relay system.

Fiber Optic Network

  • Transmitter – like the sailor on the sending ship, it will decode and sends the message.
  • Optical fiber – carries the light signal.
  • Optical regenerator – essential to boost the signals after travelling over the long distance
  • Optical receiver – finally receives and sends the real information to the captain (to another computer)


Here the sailor is the transmitter on the sending ship deck. The transmitter will receive and directs the signals in the correct sequence. Hence, it will generate the light signal.

Manufacturers will place the transmitter close to the optical fiber and contain the lens to concentrate the light and to make it the fiber. LEDs have less capacity than the lasers, and this rule may vary with the temperature, and the Lasers are very costly. The 850 nm, 1,300 nm, and 1,550 nm are the light signals regarding the standard wavelengths.

Optical Regenerator

Sometimes the signals may cause a loss when the light is made to travel through the fiber for the vast distances like the with undersea cables. Keeping it in mind, makers will splice one or more optical regenerators to activate the light signals which are deactivated.

The optical regenerator contains the optical fiber and they have special coatings (doping). They will pump the coating region with the laser. When the degraded signals reach the doped layer region, then the energy generated by the laser will make the doped molecules to mould themselves as the lasers. The doped molecules will release a new, stronger light signal and they resemble the same characteristics as that of the incoming weak light signal. The regenerator is a laser amplifier for the incoming signal.

As they will change like the new and stronger light signals and they are similar with the weak light signals characteristics. It works like the laser amplifier for the ingoing signals.

Optical Receiver

It resembles the sailor who is the receiving the signals on the other ship. This optical receiver will gather the incoming digital signals, and decodes them. It then sends the electrical signals, and they will reach the other user’s computer, telephone and TV (like a captain on the same ship). To detect the light, it will make use of the photocell or photodiode.

3.0 Advantages of Fiber Optics:

Fiber Optic Network

Less expensive:

We can get them cheaper than the copper wires. They will save our money.

Thinner: They are thinner as makers will draw it and made them at a smaller diameter. Optical fibers are smaller than the copper wires.

Higher carrying capacity:

As they are thinner than the copper cables, we can bundle some fibers into the cable. It will permit the phone lines to enter through the same cable, and they will come out with the same cable.

Less Signal Degradation:

Fiber optics degradation is less when we compare them with the copper wire.

Light Signals:

The light signals from one fiber will not connect with the other fiber light signals. So, we can get real phone conversations or TV signals.

Low Power:

As the less number of signals degrades, it is enough if we use the lower-power transmitters. It has the low power transmitter than the one in the copper wires. Copper wires require the high-power transmitters. Again this aspect will save money for us.

Digital signals:

We can use them for carrying the digital information. At present, we are using them in the computer networks.


As no electricity will pass through the optical fibers, there is no change to have the fire hazards.


Optical cable has less weight when we compare the weight with the copper wire cable. Hence, they will take less space when we equip them in the ground.


Due to the flexible nature, we are using them to transmit and receive the light. So, we are using them in the flexible digital cameras.

In addition to these, we can use them in medical imaging, mechanical imaging and in plumbing.

4.0 Conclusion:

Due to the above advantages, we are using the fiber optics in many industries mainly in the telecommunications and computer networks.

Fiber Optic Network

For Example, if you are in the Europe and wanted to speak with the people in the United States then we will hear the echo if the signal gets a bounce. But by introducing the transatlantic fiber optic cables, we can escape from the echoes. We can enjoy by having the direct connection with the one whom we want to speak.


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