Advantages & Disadvantages of optical fibre over normal electrical cables

Advantages:

• Information can be carried by radio waves transmitted down coaxial cables at a rate of about 10⁷ bits per second. But this can be increased by several orders of magnitude if information is carried as light pulses down an optical fibre. A typical optical fibre cable can carry about 9000 telephone channels, or over 1000 music channels, or 8 television channels, which is over five times the capacity of the best copper cable.
• Optical fibres can carry information over greater distances without significant attenuation. Coppoer cables require boosters to be spaced much closer together.
• An optical fibre cable is lighter, smaller and easier to handle than a copper cable.
• Optical signals are free from ‘noise’ due to electrical interference.
• ‘Crosstalk’ between adjacent channels is negligible.
• Also, because light waves do not create an external magnetic field (unlike an electric current flowing down a wire), they are far less susceptible to external surveillance.
• Apart from communication, optical fibres can be used as endoscopes in medicine and engineering to ‘see’ inaccessible places. This means that ‘exploratory surgery’ can be avoided.

Disadvantages:

• Limited physical arc of cable. Bend it too much and it will break.
• Difficult to splice.
• Physical vibration will show up as signal noise.
• Loss of light in fibre due to scattering. (Attenuation)

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