Photonics in switching: the next 25 years of optical communications?

Twenty five years ago, modern optical communications was launched in the now famous paper outlining the theory of single mode fibres by Charles Kao and George Hockham. Almost exactly half that time ago, the first fibre systems carried telephone traffic (BTRL and STL) whereas today, fibre is the universal wideband transmission medium. However, having made almost unlimited bandwidth available at low cost, the problems have now moved firmly to the network nodes, the switches, and much interest centres on whether optics can contribute here. The author examines some of the many ways in which this might come about, ranging from `all optical networks´ through to `synchronous digital-optic free-space´ switches