OPTICAL FIBRE COMMUNICATION AND OPTICAL FIBRES

Jun 17 • Notes • 1790 Views • 4 Comments on OPTICAL FIBRE COMMUNICATION AND OPTICAL FIBRES

OPTICAL FIBRE COMMUNICATION AND OPTICAL FIBRES

MOTIVATION:-

-The use of optical fibres as transmission unit provided high capacity data transfer because of the characteristics of these fibres. The use of these fibres was much more beneficial than using the traditional copper wires for transmission.

Some of the key feature of these fibres were:-

-The data could not be transmitted to large distance without losses and congestion of traffic.

-The bandwidth of these fibres were much more and thus could carry much more traffic.

-The optical fibres were much smaller in size and less heavier.

-The security of data was much more as it provided immunity to interference and and noise.

KEY ELEMENTS OF OPTICAL FIBRE SYSTEM:-

The key elements of an optical fibre are-
-Transmitter:It contains the source.The source can be a LED or a diode.

-Optical fibre: The fibre is chosen according to the use and it acts as a channel for the transmission of data.

-Receiver-It contains the filter required to remove unwanted signals and amplifier.

-Active and passive devices for other performance purposes.

OPTICAL LAW:-

Total Internal Reflection –The principle of operation in optical fibres is total internal refection.In this case the light is reflected again and again as it strikes the boundary of the medium.

MODES OF OPTICAL FIBRE:-
1) MULTI MODE FIBRE:-
-These are fibres which have less core diameter and allow the propagation of large number of rays.

– they are cheap and used for communication at short distance.

2) SINGLE MODE FIBRE:-
– It has a narrow daimeter and thus allow only one light ray to pass through them.

STEP INDEX FIBRE:-

-In a step index fibre the refractive index is constant at core and changes  at the cladding.

GRADED INDEX FIBRE:-

-In a graded index fibre the refrative index changes as we move away from the center of the fibre.

 

PHOTONIC CRYSTAL FIBRE:-

-These are also called as micro-structured fibres because of a cross section of glass and air spaces.

-They have a pattern of voids or air holes that run parallel to its axis.The core and the cladding is made up of same material and the wave guiding is provided with the help of voids.

FIBRE FABRICATION:-
–  It includes modified  lathes, a glass working lathe, a 6m high double sided fibre drawing tower for silica optical fibre.

FIBRE OPTIC CABLES:-
There are two cables:-
Tight Buffer Tube Cable
Loose Buffer Tube Cable

Tight-Buffered Cable:-
– These are used for home applications.

– It is more robust than loose buffered cable and has a plastic layer coating and waterproof acrylate. These prevent the core from moisture.

– They are used as jumpers.

– They are used for alternative routing.

Loose-Tube Cable:-
– It helps to identify fibers in the system.
– They are used to protect optical fibers.
– They are used for plant installation and direct-buried applications.

FREQUENTLY ASKED QUESTIONS WITH ANSWERS

1) WHAT ARE THE KEY ELEMENTS OF OPTICAL FIBRE SYSTEM?
Ans:T
he key elements of an optical fibre are-

-Transmitter:It contains the source.The source can be a LED or a diode.

-Optical fibre: The fibre is chosen according to the use and it acts as a channel for the transmission of data.

-Receiver-It contains the filter required to remove unwanted signals and amplifier.

-Active and passive devices for other performance purposes.

2) WHAT ARE THE MODES OF OPTICAL FIBRES?

Ans:1) MULTI MODE FIBRE:-

-These are fibres which have less core diameter and allow the propagation of large number of rays.
– they are cheap and used for communication at short distance.

2) SINGLE MODE FIBRE:-
– It has a narrow daimeter and thus allow only one light ray to pass through them.

 

3) WHAT ARE STEP INDEX AND GRADED INDEX MODE FIBRE?
Ans:-

STEP INDEX FIBRE:-

-In a step index fibre the refractive index is constant at core and changes abruptly at the cladding.

GRADED INDEX FIBRE:-

-In a graded index fibre the refrative index changes as we move away from the center of the fibre.

4) WHAT ARE PHOTONIC CRYSTAL FIBRE AND FIBRE FABRICATION?

Ans:– PHOTONIC CRYSTAL FIBRE:-
-These are also called as micro-structured fibres because of a cross section of glass and air spaces.

-They have a pattern of voids or air holes that run parallel to its axis.The core and the cladding is made up of same material and the wave guiding is provided with the help of voids.

FIBRE FABRICATION:-
-It includes modified lathes, a glass working lathe, a 6m high double sided fibre drawing tower for silica optical fibre.

5) WHAT ARE FIBRE OPTIC CABLES?
Ans:- There are two cableS:-
Tight Buffer Tube Cable
Loose Buffer Tube Cable
Tight-Buffered Cable:-
– These are used for home applications.
– It is more robust than loose buffered cable and has a plastic layer coating and waterproof acrylate. These prevent the core from moisture.

– They are used as jumpers.

– They are used for alternative routing.

Loose-Tube Cable:-
– It helps to identify fibers in the system.
– They are used to protect optical fibers.
– They are used for plant installation and direct-buried applications.

GATE Syllabus

1.Gate syllabus for Electronics and Communication Engineering

2. Gate syllabus for Computer Science and Information Technology

IES Syllabus

1. IES Syllabus for Electronics and Telecomm

2. IES Syllabus for Electrical Engineering

 

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4 Responses to OPTICAL FIBRE COMMUNICATION AND OPTICAL FIBRES

  1. KITUNDU ORGENES says:

    explanation of procedures to follow on transmission of signal in optical fibres in digital communication

  2. Dinesh says:

    These optical fiber are playing very important role in wired communication,,, because of the speed this cable are still in use, so details about cable are very useful

  3. Mrityunjay Kumar Singh says:

    A good composed note on optical fibre. It provides all the basic concepts of the Optical Fibre.

  4. Amit Kumar says:

    Opticle fibre is a very good medium for communication with minimum delay and minimun data loss. This article is a good collection about basic of Optical fibre

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