The unprecedented proliferation in big data and IP traffic across interlinked data centers (DC) and high‐performance computing systems (HPC) has made ultra‐high link capacity and packet switching rate at network nodes necessary. To meet these very high demands, especially packet routing and forwarding, well‐proven technologies, such as the optical switching and labelling technology, seem to provide appropriate solutions, not only by delivering high‐bit rate data streams, but by achieving cost‐efficiency and energy‐efficient multi‐Tb/s cross‐connection throughputs. Experts predicted that optical switching would serve as the basis for the construction of seamless integrated networks to transmit all traffic via the same fiber line and offer other pathways for traffic to cross if a channel collapses. The net outcome is a quicker, more convenient internet, claim proponents. Therefore, up‐to‐date extensive information of optical switching and its application in modern optical networks is strongly needed for researchers to keep up with the recent technological advancement. Given this scenario, this book is planned to provide a comprehensive source of guidance on optical switching.

This book has several objectives. First of all, we lay the groundwork by offering a brief review of the optical switching and networking and the significant successes of recent decades, highlighting key enabling technologies and techniques that have paved the way for modern optical switching networks. We will next explore the broad overview of the future of optical switching and identify important milestones in the development of optical switches of the next generation. In the first section, a detailed introduction opens the way for the reader to learn the history and principles of the topic. The second section focuses on the switching devices, the concepts and theories of several optical switching technologies, characteristics, and application areas. The third section explores the optical switching applications in communication networks.

Today, optical switching covers a range of technologies and numerous scientific and engineering fields. It is not simple for one to master several areas in this subject, as with many modern domains of study. Thus, an edited book of its kind, with several writers, will give the reader better insight into the subject. We appreciate profoundly the effort, passion and quality of the work of the chapter authors. We are very thankful to many of them, who have not only given their chapters but were also gracious enough to provide important advice and recommendations on the preparation of this book.

Finally, this book is intended to offer readers with an in‐depth overview and an in‐depth grasp of state‐of‐the‐art optical switching as well as recent and substantial advances in the field of optical switching and networks. It also will be a support for researchers, engineers, and experts in developing applications and services in this field. We hope that this book will appear as a one‐volume reference for researchers, senior and postgraduate students, and professionals requiring quick expertise in the most recent technologies.