In recent decades, cosmetic science has found new high-potency, bioactive ingredients that produce visibly superior skin benefits to the consumer. Light-based devices, including lasers and intense-pulsed light systems, have been used for years in the treatment of cutaneous vascular and pigmented lesions, yet have only recently appeared in cosmetic applications, beauty salons and spas. Meanwhile, ever more research and development is being performed with the intent of bringing them to the home-use market. This book is the first to introduce a range of currently used, or under development, laser- and light-based technologies that will provide greater cosmetic benefits to the consumer. It explains the basic physics of light-based technologies, the bio-physical principles behind their mechanism of action, and their applications in many cosmetic procedures.