This book focuses on areas of integrated optics which is an emerging technology. This book includes the basic concept of a micro ring resonator and its characteristics. The generalised approach of the device design is described, and some cases of applications are provided. The non-linear aspect of the micro ring resonator is also analysed; there are some cases of applications provided. Evolving technologies in communications, quantum communication, non-linear communication, ultra-fast switching and soliton switching, quantum chaotic and solitons are discussed.