Pulse propagation along glass fibres

Mode-locked helium-neon lasers have been used to propagate pulses of ~1 ns duration along multimode cladded glass fibres. Any pulse spreading due to dispersion in a 33 m length of fibre is less than 0.5 ns which is the limit of resolution of the measuring equipment. This result indicates that a pulse transmission rate of at least 33 MHz may be possible over a distance of 1 km.