- 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.
- 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)