Single optical fibre line multichannel transmission system - uses superposition of different wavelengths or bands for subsequent separation by filtering

摘要

The system utilises a red (1) and a green (2) light emitting diode which are coupled to a fibre optic cable (6) through a coupler (5). The diodes are biassed so that one is energised by positive pulses (2) while the other is energised by negative pulses (4). At a receiver, the cable is split into two, each part communicating respectively with a red filter (8) and green filter (9). The positive and negative signals are then recovered from the red and green light pulses using photoelectric generators suitably biassed. A wide band light source with a large number of colour or interference filters may be used to provide a large number of channels.