Fibre Optic

It is a communication technology to carry data and information along a glass fibre by use of light. What is fiber optics? Fibre optic is a long, thin strands of pure glass and diameter of fibre optics is so small as about the diameter of human hair. Fibre optics is used to transmit the light signal along a long distance .Fibre optical communication system revolutionized the telecommunication. Optical fibre have replace copper wire communication in core networks in the developed world because of its advantage over  electrical transmissions. Optical fibre uses in telecommunication companies to transmit telephone signal, cable television signal, internet communication. Fibre optic has the 3 parts, the name of these parts is

Core - Thin glass centre of the fibre, the part where the travels light.

Cladding – An outer optical material that surround the core.  It reflects the light back into the core.

Buffer coating –A plastic coating that protects the fibre from damage and also protect from moisture.

Optical fibres come into two types.

1: Single mode fibre

2: multi - mode fibre

Single mode fibre:-

Single mode fibre optic cable has a core of small diameter in which only one mode of light propagate. As light passes through the core, creation of number of light reflection is  decreases lowering the attenuation and increasing the ability for the signal to travel faster and for long distances .This is used in telecommunication companies , colleges and universities.

Multi-mode fibre

Multi – mode fibre optic cable has a core of large diameter in which multi mode of light propagate.

As light passes through the core, creation of number of light reflection is increases. The ability for more data to pass through at a given time increases. Because of a high dispersion and attenuation, the ability for the signals to travel over a long distances decreases. This is used in audio or video application in LANs.

How optical fibre transmit light???  The light in fibre optic cable travels by uses of principle of total internal reflection that is light travel through the core by constantly bouncing from cladding. Purity of glass and wavelength of light determine the extent of the signal degraded.

Fibre optics transmission system:

It consists of following:

1 -transmitter: It produces and encodes the light signal

2 -optical fibre: conduct the light signal

3 -optical regenerator: necessary to boost the light signal for long distance

4 -optical receiver: receives the light signal and decode it.

Advantages of fibre optics:

1-Less expensive

2-Thinner

3-Higher carrying capacity  

4-Less signal degradation

5-Light signal

6-Low power

7-Digital signal

8-Non-flammable

9-Lightweight

10-Flexible

Disadvantages of Fibre optics:

1-Expensive

2-Require more protection

3-Fragile

4-Transmission requires repeating at distance intervals.