Repeater spacings of digital communication systems using optical waveguides

The repeater spacing of digital communication systems using optical waveguides is calculated according to the available optical power. The theoretical results are valid for all types of optical waveguides of sufficiently broad bandwidth using any type of optical power diode. Experiments using an l.e.d. demonstrated the possibility of transmitting at 80 Mbit/s along a graded-index fibre of 4 km length. Transmission at 34 Mbit/s is also possible over a distance of 5 or more km. For transmission at 8.5 Mbit/s, a step-profile fibre of the same length, is sufficient.