OPTICAL FIBRE

 OPTICAL FIBRE

Optical fibre is the technology associated with data transmission using light pulses traveling along with a long fibre which is usually made of plastic or glass. Metal wires are preferred for transmission in optical fibre communication as signals travel with less damage. The fibre optical cable uses the application of total internal reflection of light. Optical fibre is also unaffected by electromagnetic interference. The fibre is designed in such a way that they facilitate the propagation of light along with the optical fibre depending on the requirements of power and distance of transmission.

Types of optical fibre:

The type of optical fibre depends upon the refractive index, the material used, and the mode of propagation of light. The classification based on the mode of propagation of light is as follows:

a) Single-mode fibres : these fibres are used for long-distance transmission of signals.
b)Multimode fibres : these fibres are used for short-distance transmission of signals.

The classification based on the materials used is as follows :

a) Plastic optical fibres : polymethylmethacrylate is used as a core material for the transmission of light.
b) Glass fibre: it consists of extremely fine glass fibres.

The classification based on the refractive index as follows:

a) Step index fibres: it consists of a core Surrounded by the cladding which has a single uniform index of refraction.
b) Graded index fibres : the refractive index of the optical fibre decreases as the radial distance from the fibre axis increase.

Working principle of optical fibre:

The optical fibre works on the principle of total internal reflection. Light rays can be used to transmit a massive amount of data, but the problem arises - that the light rays travel in Straight lines. So unless having a long straight wire without any bends at all, harnessing this advantage will be very tedious. Instead, the optical cables are designed such that they bend all the light rays inward ( using TIR) . Light rays continuously, bounce off the optical fiber walls and transmitting end to end data. Although light signals degrade over progressing distance, depending on the purity of the material used, the loss is much less than using metal cables.A fibre optics relay the system consists of the following components:

a) The transmitter:  produces the light signals and encodes them to fit to transmit.
b) The optical fibre: the medium for transmitting the light pulse( signal).
c) The optical receiver: it receives the transmitted light pulse and decides them to be fit to use.
d) The optical regenerator: necessary for long-distance data transmission.

Advantages of optical fibre communication:

a) Economical and cost-effective.
b) Less power consumption.
c) Flexible and lightweight.
d) Less signal degradation.
e) Thin and nonflammable.
f) Not affected by interference.
g) Data security is excellent.

Disadvantages of optical fibre communication:

a)The cost to produce optical fibre cable is higher than that of copper.
b)They are made of glass, fibre optic cables are more fragile than electrical wires like copper cabling.

Uses of optical fibre :

● Medical Industry
● Communication
● Defence
● Industries
● Broadcasting
● Lighting and decorations
● Mechanical Inspection