Optical fibre communication
No TL;DR found
Abstract
Optical fibres and their associated signal processing of laser pulses are the backbone of modern communications but, without exception, every aspect of their structure, and component items, rely totally on extremely fine and accurate control of impurities, which were once discussed as unwanted dopants and imperfections. The history and techniques to make the fibres are discussed from their initial usage in medical internal probes for visual inspection, their progress from a limited useful range of a metre (because of optical absorption) to networks measured in hundreds of kilometre length transporting, and sorting, millions of signals simultaneously. The challenges are to add dopants to vary their refractive index, remove those that absorb light, and add others to create fibre lasers and amplifiers, and to do all such steps simultaneously is an incredible achievement. Without optical fibres the world as we now know it could not exist.