Optical Switching is the most comprehensive and up to date reference book on its subject. After three decades of research and development efforts, optical switching has started to be deployed in cutting-edge networking initiatives. The optical devices, optical networks, and telecommunications/data networking communities are in need of a reference book that compiles diverse optical switching research, from device technologies to system and network architectures, into one properly structured volume. This book provides such a service to these communities. The book is structured into three parts. The first part provides the foundation for understanding the potential role of optical switching in communication networks. The second part is focused on optical switching technologies and on devices based upon them. Theories, operation principles, and fabrication techniques are discussed. The third part covers optical-switching fabrics, systems, and networks. Applications of optical switching in communication networks are discussed, involving optical circuit, packet, and burst switching. The chapters are self-contained with minimum overlap. They bring together academic and industrial contributions, analytical and descriptive treatments, and cover theories, experimentation, and practice. The material has been carefully coordinated to form a homogeneous manuscript having a progressive and logical development of ideas and concepts. The book embraces a number of distinctive innovations. Old and new terminologies are investigated, clarified, redefined where necessary, and used consistently throughout the entire volume. The treatment of the subject is original, not only in terms of comprehensive coverage, but also in terms of structure and organization. Twenty-four authors contributed the fourteen chapters of this book, including the Editor Tarek S. El-Bawab who authored four chapters.