9 optical transmitters; lasers, light emitting diodes; optical receivers, detectors and sensors; optical waveguide and waveguide devices; optical switches, modulators, computers and signal processors; optical couplers and connectors; optical amplifiers and attenuators; fibre devices; devices for the processing, logging, storing, transmission, reception or print-out of data; combinations of any of the foregoing; control circuitry for any of the foregoing; parts and fittings for any of the foregoing