Tutorial: optical cross-connect and add-drop multiplexers: technologies and applications

One of the most significant changes in telecommunications networks over the last decade has been a movement towards management at the wavelength level, rather than in smaller units of bandwidth. Optical crossconnects and add-drop multiplexers are the network elements that enable this wavelength-by-wavelength network management. This tutorial will begin by reviewing the likely evolution of long-haul optical telecommunications networks, and the role of optical crossconnects and optical add-drop multiplexers in this evolution. We will examine several broad classes of optical crossconnects and add-drop multiplexers, and the types of networks they enable. We will then focus on technologies for the switch fabrics in these elements.