Advancing from 2000 entries in the second edition to 16,000 entries in this edition, this volume offers a comprehensive, illustrated guide of definitions reflecting the latest trends in the design, development, manufacture, installation, operation, application, and maintenance of optical systems and components. Particular emphasis is placed on fibre optic and lightwave communications systems as well as other optical systems, from optical fibre and laser beam transmission systems to interfaces with electronic systems and imaging systems. Practically every definition carried over from the second edition has not only been recast with improved clarity, style, format, accuracy and precision, but has also been augmented with additional explanations, illustrations, examples, and cross references. This book should be of interest to electrical and electronic engineers, telecommunications and communications specialists and related professionals, practicioners, and academics in communications, computers, multimedia, telephony, control systems, and digital signal processing.