Definition of Optical Fiber and its Functions

This time I will discuss about Fiber Optic (Fiber Optics). Understanding Fiber is a transmission line or a kind of cable made of glass or plastic that is very smooth and smaller than a hair, and can be used to transmit light signals from one place to another. The light source used is usually a laser beam or LED.

This cable is approximately 120 micrometers in diameter. The light that is in the optical fiber does not come out because the refractive index of glass is greater than the refractive index of air, because the laser has a very narrow spectrum. Fiber optic transmission speed is very high so it is very good to use as a communication channel.

Definition of Optical Fiber and its Functions

The development of fiber optic technology today, has been able to produce attenuation (attenuation) less than 20 decibels (dB)/km. With a line width (bandwidth) is large, so it is capable of transmitting more and faster data compared to the use of conventional cables. Thus, optical fiber is very suitable for use, especially in telecommunications system applications.

About 20 years ago, fiber optic cable has taken over and changed the technological face of the long-distance telephone industry as well as the automation industry with remote control. Optical fiber also plays a big role in making the Internet usable all over the world. In 1997 fiber optics connected the whole world, the Fiber-Optic Link Around the Globe (FLAG) became the longest cable network worldwide providing the infrastructure for the latest generation of internet.

Understanding Fiber Optic

Fiber Optic is a type of cable made of glass or plastic that is very small measuring 120 micrometers like a hair, even thinner than a human hair but with the ability to transmit data up to tens of kilometers away without significant data loss.

As the cable in general serves to deliver electricity or a certain signal, so also the basic function of optical fiber. The difference with copper cables is that the electrical signal is first converted into light and transmitted through glass fibers in the form of strands.

Fiber optic cables commonly planted under the sea can consist of several hundred optical strands, and each optical strand can connect up to 25,000 telephone calls. So with just a few fiber optic cables, you can easily connect up to millions of phone calls. Can be compared with copper cable which is very limited in data transfer capability and transmission range.

For comparison, here is an illustration:

Difference Between Fiber Optic vs Copper Cable

It can be seen not in terms of distance and bandwidth, the capabilities are very far apart so that where the FO can be used up to a distance of 40,000 km and the ability to transfer data up to 69,000 Mbps

Fiber Optic Working Principle

The way optical fiber works is actually very simple, namely data which is in the form of an electrical signal is converted into light and in fiber optic cables this light is reflected and refracted so that it can propagate from one end to the other, the light source itself can come from a laser or LED diode. Because it is made of pure glass fiber, light waves can be transmitted for kilometers.

Now the data that has previously been converted into the form of light is modulated into a fiber light wave to be forwarded to the other end of the optical fiber and then converted back to the original data. In this process, the role of the transmitter and receiver is

Fiber Optic Working Principle

Because basically fiber optic cables conduct light, in the process there will be no electromagnetic problems that may arise from nearby devices or from other fiber optic cables, this is very important for data security which may be done by tapping electromagnetic signals on copper cables.

Fiber Optic Arrangement

The arrangement of fiber optic cables is more complicated than copper cables because there are many protective layers whose function is to protect the core of the fiber optic cable itself. In general, the arrangement of fiber optic cables consists of:

  1. Core / core, is the core of a fiber optic cable that plays a major role in transmitting data. Although it is very small and even thinner than a human hair, its ability to transmit data is much better than copper wires. Usually the material for the core is a transparent filament type material / pure glass that can reflect light
  2. cladding, is the first protective layer that is in direct contact with optical fiber usually made of silicon which is also able to reflect the light that comes out to return to the core so that no light comes out.
  3. Coating, is a layer of plastic that is elastic as a physical protection such as bending of cables etc.
  4. Jacket, is the main layer for protection from the outside to protect against damage. In this jacket is also usually given the color of the cable according to the standard. This layer on the type of underwater fiber optic cable can be very thick because it must last for decades under the pressure of sea water.
Definition of Optical Fiber and its Functions

On the outer sheath of fiber optics we can find several different cable colors, the color of this cable has a standard that indicates the type of fiber optic cable itself, here are the standard fiber optic cable color codes that are currently used:

Fiber Optic Cable Type

Based on the transmission mode, optical fiber consists of 2 types, namely single mode and multi mode, the use of both is different and has advantages and disadvantages of each:

Single Mode Optical Fiber

In the single mode type, it uses laser light to transmit data and is passed to the core / core of the cable in a straight line so that the data transmission range is further. Single FO cables also have a smaller core with a core diameter of only 9 microns, while the wavelength of the light itself is around 1310 to 1550 nanometers.

The light sent does not reflect off the wall cladding and can only send one signal at a time. This cable is used for sending data over long distances such as underwater fiber that can connect between countries.

Single Mode Optical Fiber

Multi Mode Optical Fiber

In Multimode Optics, the core diameter is larger, namely 625 micrometers so that it can reflect several beams of light which actually causes a decrease in the bandwidth ability of the data sent, but the advantage is that it can send different data simultaneously.

Likewise with the range, there is a difference, if in single mode it can transmit data up to hundreds of kilometers, then in multimode it can only reach a distance of 550 meters.

Multi Mode Optical Fiber

Fiber Optic Function

Basically the function of Fiber Optic cable is the same as other types of cables, namely connecting computers or users to each other and within a certain network scope. What makes the difference is the high speed of access and the ability to transfer data faster. For the speed of data transmission can be up to the range of Gigabits per second. In addition, because it does not carry electricity, this type of cable is also not affected by electromagnetic interference so that it is stable in use.

But of course, with the many advantages obtained, of course, you have to pay more, which is why this type of cable is not used by anyone. Usually large-scale companies and telecommunications operators prefer to use this fiber optic cable. Even today, Wi-Fi development companies have started using Fiber Optic because it is faster and more stable.

Advantages and Disadvantages of Fiber Optic

Although it comes with higher capabilities than the previous type of cable, it does not mean that this Fiber Optic cable does not have any drawbacks at all. Below we explain the various advantages and disadvantages that you can get when using Fiber Optics:

Advantages of Fiber Optic

  1. This type of Fiber Optic cable has the ability to deliver data with large capacities and very long transmission distances. With a capacity of Gigabytes per second, it gives internet and telephone companies the freedom to choose high bandwidth.
  2. Despite having great capabilities, the physical form of this cable is smaller when compared to other types because the material is made of glass fiber and plastic. This allows the availability of large enough space.
  3. Because it does not use an electric current, this Fiber Optic cable is free from interference from electromagnetic signals, radio signals, and has a fairly strong resistance, so it is widely used by large companies.
  4. Even though it has a high access speed, the possibility of data loss is very low, so you don’t have to worry about data validity.
  5. Because it does not use electricity, the possibility of a short circuit will also not occur, so in terms of security it is also very guaranteed.

Disadvantages of Fiber Optic

  1. The biggest drawback of Fiber Optic cables is that the price is quite high, this is very reasonable considering the materials used and the installation. Therefore, users of this type of cable are not arbitrary, but companies or communication service providers who really want faster access.
  2. In addition to being expensive at the time of installation, Fiber Optic maintenance also costs a lot of money considering the tools used are also not cheap.
  3. Also pay attention to the placement of Fiber Optic cables, usually installed on paths that turn or have curved angles so that the process of traveling waves can be smoother or not hampered.

How Fiber Optic Works

Previously, it was explained that Fiber Optic cables do not conduct electricity but light. The electricity obtained is converted into light signals and passed between computers connected in a large-scale network. This makes Fiber Optic cables very suitable for use in areas with a lot of electromagnetic interference.

If in Coaxial or Twisted cables, the length of the cable is often an obstacle, but this does not apply to Fiber Optic cables. Raw materials made of pure glass fiber are able to carry light to transmit data continuously regardless of the length of the cable used. The point is in the Fiber Optic cable using a working method by utilizing a mirror to produce a total internal reflection or the general language is a total reflection on the glass fiber part.

That’s the understanding of Fiber Optics that you need to know, especially if you want to install a network. Even though it has a fairly high price, but by looking at the benefits and benefits obtained, it is very natural that some large companies prefer this type of cable.

That was the understanding of fiber optics and their functions, hopefully it will be useful.