Optical communication is very much useful part in our advanced fibre-based telecommunication systems, data processing and networking. It consists of a transmitter that encodes a message into an optical signal, a channel that carries the signal to its desired destination, and a receiver that reproduces the message from the received optical signal. It presents up to date results on communication systems, along with the explanations of their relevance, from leading researchers in this field. The chapters cover general concepts of optical communication, components for optical communication, optical communication systems and networks, signal processing and MIMO systems. In recent years, optical components and other enhanced signal processing functions are also considered in depth for optical communications systems. The researcher has also concentrated on optical devices, networking, signal processing, and MIMO systems and other enhanced functions for optical communication. This book is targeted at research, development and design engineers from the teams in manufacturing industry, academia and telecommunication industries. This book presents a high level technical overview of the emerging technologies of optical communication and networking systems. It is intended as an introduction to the field for optical communication and network professionals, such as higher degree research students, academics and design engineers. Although it is intended for professionals who already have some technical background, it is nevertheless relevant to anyone wishing to understand optical communication or networking.