As the bare hair-thin fibre is typically only 125 microns in diameter, the challenge was to increase the working diameter while maintaining concentricity. Modern connectors are factory made, and spliced into the cable, eliminating the need to work on connectors in the field.
The Jewel Ferrule, the basis of all the early connectors, was developed at ITT Components Group at Edinburgh Way in Harlow, by Audrey Crick & Mike Phillips
Early splicing techniques often employed adhesives, or precision fibre alignment tubes. Soon the technique of fusion splicing fibres was developed, initially using a gas flame, later using a tiny electric arc. Modern splicing is achieved almost completely automatically and with incredible accuracy, and hence negligible loss.