Optical networks have long played a central role in telecommunication networks, forming the fiber backbone of the Internet. Over time fiber optic systems have evolved and found deployment increasingly closer to the network edge. Today, optical systems extend to the server network interface cards and home access networks. New application areas have emerged such as the use of free space communications using LiFi technologies, space communication networks between satellites and ground stations. Looking ahead, optical systems in many areas will continue to be driven by the need for higher speeds and capacity in order to keep up with traffic demands. In addition to faster interfaces speeds, parallel fiber or spatial division multiplexing will be...