Add-drop multiplexers and cross-connects for multiwavelength optical networking

Summary form only given. Wavelength add-drop multiplexers (WADM) and cross-connects are being constructed at Lucent Technologies for the MONET (multiwavelength optical networking) Washington D.C. network. Add-drop multiplexers and cross-connects enable single wavelength signals to be added and dropped at various nodes, thus providing an efficient means of access to the optical layer. Further, they allow flexible routing of wavelengths to effectively accommodate changing traffic demands.