Book excerpt: This book presents recent and important developments in the field of Photonics and Optoelectronics, with a particular focus on Laser Technology, Optical Communications, Optoelectronic Devices and Image Processing. At present, Photonics and Optoelectronics Technologies are pivotal to the future of laser, displays, sensors and communication technologies, and currently being developed at an extraordinary rate. This book details the theories underlying the mechanisms involved in the relevant Photonics and Optoelectronics. Devices such as laser diodes, photodetectors, and integrated optoelectronic circuits are investigated. The reviews by leading experts are of interest to researchers and engineers as well as advanced students.