Introduction to Optical Fiber

What is Optical Fiber

Introduction to Optical Fiber

The optical fiber is a type of wire that is transparent fiber and also very flexible made up from silica or can be made of plastic that is just thick compare to human hair. The major use of it is for transmitting the light and also used to establish the fiber-optic communication. It is capable of transmitting the signals for long distance but the cost of fiber is little expensive compare to other type of cable. The optical fiber is capable of handling all type of external interference and signals quality is not compromised.

Different Types of Optical Fiber

Given below are the different types mentioned:

1. Single-mode

In the single-mode optical fiber there is only one mode that is used to transmit light. The cable is capable of transmitting only one type of wavelength of light in the cable. The transmission wavelength for the single-mode is around 1310 nm- 1550nm. As there is limitation of transmitting only one mode of light but the single-mode is capable of transmitting with less loss compared to multi-mode optical cable. The bandwidth is much higher in this mode compared to other types of optical fiber. The development of single mode fibers is latest compared to multimode type of optical fiber cable.

The core size in single-mode optical fiber is very small that is nearly equal to wavelength size. The light pass in this mode does not come under visible spectrum. As the direction of transmission is straight the chance of signal loss is very few and quality of transmission is very high. The single-mode optical fiber is mostly beneficial where there is requirement of sending signals for long-distance and speed of transmission needs to be high. The only disadvantage in this mode is that the single-mode is not easy to couple.

2. Multi-mode

In the multi-mode optical fiber there can be multiple mode that can be used for transmit the light. In multimode different mode of light can be easily transmitted. The size of core is thick in multi-mode compare to single-mode optical fiber. The wavelength of light transmitted in this cable is nearly around 850-1300 nm. As in this type multiple modes of light are transmitted every light has different angle of reflection and on basis of this total reflection number varies. There can be also a mode of light in which light did not get strike with core for one single time. The main principle used in it is transmission is total internal reflection so there can be some mode of light that has some angle of reflection that do not cause internal reflection hence it gets absorbed by cladding layer of it.

And because of this loss are occurred while transmission of light. As there are multiple modes of light that get transmitted in cable which have different angle of reflection and due to higher number of reflections the signal can be completely lost inside the cable only and will not reach to destination end. The lower wavelength light mode gets transmitted in straight line so that quality of signal is not compromised. The multimode optical fiber can be further categorized into stepped index multimode and graded index multimode cable.

3. Micro structured

The micro structured is new category of optical fiber cables. The micro structured type uses different concept for transmission of light from one end to another end. In the micro-structured optical fibers the light get transmitted because of reflective indices and total internal reflections. All this transmission is done inside the core part and cladding part of it. The micro structured cable is of multiple type like photonic crystals, fresnel fibers and air-clad fibers or double-clad fibers. Popular Course in this categoryAll in One Software Development Bundle (600+ Courses, 50+ projects)600+ Online Courses | 3000+ Hours | Verifiable Certificates | Lifetime Access
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4. Plenum

The development of optical fibers can also be based on the industrial requirement so that they can directly installed in the air plenums. The major application of this type is in buildings and complex. This type of optical fiber cables is even fire-proof that make this cable popular.

5. Simplex

In this type of optical fiber there is only one glass strand. This type of cable is mostly prefer when there is requirement of transmitting single mode of light from one end to another end. It can also be used when there is requirement of sending multiplex data signals that means both direction communication.

6. Duplex

In this type of optical fiber there can be multiple glass strand. The duplex mode communication is possible between the devices in which one line can be for transmission and one line for receive.

How Optical Fiber work?

In the optical fiber, the lights are transmitted very fast as they get reflected inside the optical fiber and get transmitted from one end to another end. The reflection of light take place continuously in it. In it there is one core part in which actual transmission of light take place. The core is glass like structure that present exactly in middle of optical cable. And a=outside the core layer there is another glass like layer known as cladding.

The cladding layer is used to sustain light signals inside core layer only. They are bundled up to form the optical cables. There is one outing layer named as jacket that protects the bundles. In it the data is send in form of light that is encoded at sender end and at the receiving end the light is decoded as data that can be processed at receiving end. The transmission of signals in it is very fast compared to other type of cable.


The optical fibers are the transmission medium of light that is very fast medium so that signal can be transmitted from sender end to receiver end. There are multiple modes of optical fibers that are used for the transmission and selection of right mode of it is completely dependent on user requirement.

Recommended Articles

This is a guide to What is Optical Fiber? Here we discuss the introduction to optical fiber with 6 different types and how this fiber works. You may also have a look at the following articles to learn more –

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