This book concerns one of the most important developments of the last years in laser physcis, vertical cavity surface emitting lasers. They have a high potential for useful applications, ijn fact. vertical-cavity surface-emitting lasers (VCSELs) are one of the most promising new developments in laser physics. The basics, theory, design, fabrication and operation of such lasers are explained in detail. this book is the first of its kind to provide readers with a comprehensive account of the latest technological developments in VCSEL devices. In fact, all the chapters are written by pioneers and key experts who have exclusive access to the most up-to-date innovations in their respective fields. Thus, readers not only learn of the crucial aspects of VCSEL devices, including simulations and experiments, but also the underlying theory.