Optical fibres, glass structures with slightly larger diameter than a human hair, are unequivocally one of the mainstays of the global communications network. These fibres transmit light in great quantities over long distances, with a very superior bandwidth and capacity to those of the coaxial copper cables that were previously used.
The truth is that their geometric simplicity conceals their sophistication in managing light. Half a century ago, Charles Kao suggested the viability of optical fibre communications, in work that won a Nobel Prize and, since then, the domination of glass over light has done nothing but increase. The millions of kilometres of fibre installed since then are proof of this.