Engineering Physics

11.8 Optical fibres in communication

Fibre optics essentially deals with the communication [including voice signals, video signals or digital data] by transmission of light through optical fibres. Optical fibre communication system essentially consists of three parts: (a) transmitter (b) optical fibre and (c) receiver (Fig. 11.8). The transmitter includes modulator, encoder, light source, drive circuits and couplers. The light source can be a light emitting diode [LED] or a semiconductor laser diode. Basically, a fibre optic system simply converts an electrical signal [corresponds to analogue information such as voice] to binary data by an encoder and this binary data comes out as a stream of electrical pulses and these electrical pulses are ...