One of the key advances in photonic technology in recent years is the development of vertical-cavity surface-emitting lasers, or VCSELs. These devices have a huge range of potential applications in areas such as communications, printing, and optical switching. This book provides a clear insight into the physics of VCSELs, as well as describing details of their fabrication and applications. All of the book's contributors are at the forefront of VCSEL research and development. Together they provide complete and coherent coverage of the current state-of-the-art. The opening chapters cover VCSEL design, emission from microcavities, growth, fabrication, and characterization. These are followed by chapters on long and short-wavelength VCSELs, optical data links, and free space optical processing. The book will be of great interest to graduate students and researchers in electrical engineering, applied physics, and materials science. It will also be an excellent reference volume for practising engineers in the photonics industry.