Covering all aspects of optical switching, this book focuses in particular on the optical mechanisms at the origin of all-optical switching. To give readers an overall understanding of the topic, the author begins with an introductory section on different types of switching mechanisms before moving on to the topic of all-optical switching by using optical switches controlled with light. Areas covered include all-optical switching in nonlinear interferometers; all-optical bistable devices; optical limiters, and the latest developments in the all-optical switching based on nanophotonics and other principles. The author methodically works through the various switch designs, providing a theoretical analysis and numerical example for each design.