Optical Fibre Communication

TECH FACTOptical Fibre Communication SystemJune 2, 2018 - by Admin - Leave a Comment

In recent times transparent dielectric fibres have been developed to eficiently optical signals from one place to another. These are optical fibres. The study of the properties of such optical fibres as fibre optics. Usually, the diameter of these fibres is large ared to the small wavelength of optical signals. So the inherent eve nature of light may be neglected and we can apply the known Tears of geometrical optics to study the properties of optical fibres.Click here for other information

Optical Fibre

The importance of fibre optics arises from the fact that an optical fibre can worry a huge amount of information by using a light beam as a carrier wave. Moreover, because of low cost, high reliability and extremely low losses optical fibres are gradually being used more and more.

If the diameter of the fibre becomes of the order of wavelength, the wave nature of light cannot be neglected (e.g., in fibres of thin variety). In this case light travels as an electromagnetic wave along the fibre in a manner similar to that of microwave propagation along a waveguide. In order to have an idea of such mode of propagation we present at the end of this chapter a brief discussion on microwave propagation along a waveguide 16.2

CLASSIFICATION OF OPTICAL FIBRES :

Optical fibres or fibre guides are hair thin flexible structures that can guide optical signal from one place to another. An optical fibre consists of an inner cylinder made of glass or plastic, called the core. The core is surrounded by a glass or plastic coating of lower refractive index called the cladding. The function of the cladding is to add mechanical strength to protect the core from environment and to reduce scattering losses at the core surface. Optical fibres can be classified on the basis of refractive index profile of the core and the number of modes propagating in the fibre.If the core has a uniform refractive index then it is called a step-index fibre. On the other hand, if the core has a non-uniform refractive index that gradually decreases from the centre toward the core-cladding interface, the fibre is classified as graded-index fibre.

It shows a step-index fibre with relatively large core. depending on the launch angle of the incident light into the fibre, there be large number of different zig-zag ray paths or modes by which Tgy can travel down the core. Then it is called a step-index multimode.

Some of the common applications are mentioned below.

Optical fibres are nowadays being used in various fields.

1. Communication:

Most important application of optical fibres is communication. Because of high bandwidth, low loss, small size, light weight and certain other attractive features optical fibres are being extensively used in both long-distance communication and local area networks that include telephone, television, computers etc.

(ii) Transmission of light :

Optical fibres are used for transmission of light to illuminate hard-to-reach places or to conduct light out of such places.

(iii) Transmission of images:

A flexible bundle of optical fibres is called a fibrescope. It is extensibly used in carrying images. Light is passed down the outer fibres from the source and the reflected light is piped along the inner fibres.It is used in medicine to look into internal organs of human body and in non-destructive testing in industry. For full Article Click Here