Abstract

DWDM metro rings form standard optical transport topologies for metropolitan area networks. Many of such rings can be scaled together by interconnecting at discrete nodes (fig. 1). When a lightpath¹ is provisioned from ingress to an egress node the data is transmitted and received at either ends by a pair of transponder cards. These optoelectronic converters of data translate the incoming client data-stream onto a suitable ITU-T specification wavelength in the ring network. Each of these transponder cards comes in pairs of a tunable transmitter device (network side) and a wide band receiver over the entire operating-band. The tunable transmitter is desired to have a tuning range to cover the entire operating-band, but the involved cost makes this currently uneconomical, though 44 λ tunable transponder has been reported.²

© 2002 Optical Society of America