Advanced Optical Modulation Formats

High-speed optical transmission systems are increasingly building on digital signal processing and digital communication techniques that are well established in radio-frequency communication systems, including efficient forward error correction, advanced modulation, line coding, polarization multiplexing, digital signal processing at both transmitter and receiver, and coherent detection. 

Nevertheless, an optically- routed network exhibits important fundamental as well as technological differences from a radio-frequency system, and not all techniques that have proven successful in radio-frequency communication should be expected to work well for optical networks. 

This book chapter discusses the peculiarities of advanced optical modulation formats in the context of optically-routed networks, with an attempt to bridge the gap between digital signal processing and optical physics, both of which are essential to the understanding of modern optical communication systems.