An overview of very high capacity transmission technology for NTT networks

This paper describes very high capacity optical transmission system technology, which is useful for long-haul trunk lines, and has led to the feasibility of NTT´s first gigabit-per-second range transmission system. It also describes various devices and circuits, such as high performance lasers, photodetectors, very wide-band amplifiers, and high speed logic circuits required for the development of such systems. It then discusses future research areas and trends in advanced lightwave communication systems.