Optical communication is the process of using light as a medium of communication. The communication can be achieved by employing visual techniques or by using an electronic device. An optical communication system comprises of a transmitter, a channel and a receiver. The transmitter encodes a message into an optical signal, which is then carried through a channel and received by a receiver. The most commonly used channel for such communication is optical fiber. It commonly transmits infrared light through either laser diodes or light-emitting diodes. This book traces the progress of optical communication technology and highlights some of its key aspects and applications. It strives to provide a fair idea about this discipline and to help develop a better understanding of the latest advances within this field. Those in search of information to further their knowledge will be greatly assisted by this book.