Technologies and architectures for scalable dynamic dense WDM networks

Wavelength-division multiplexing has been recognized for a number of years as a promising and applied technology that can be used to increase the aggregate system bit rate. Recently, more attention has been given to devices and technologies that can be exploited to enable WDM to move from being a pure transmission technology into a state where it can be applied in transparent all-optical networks. In particular, devices and technologies such as wavelength routing switches, switched sources, tunable sources, tunable filters, and wavelength converters have all been developed and demonstrated. This article gives a description of the technologies, subsystems, and network architectures that rely on multiple wavelengths to achieve full transparent all-optical connectivity joined in many instances, with features like scalability, modularity, and survivability. Brief exposure is also given to most of the current WDM demonstrators.