<title>Photonic add-drop multiplexing perspective for next-generation optical networks</title>

Abstract

An add/drop multiplexer (ADM) is recognized as one of the basic building blocks to extend DWDM networks from a static point-to-point system into a next generation, dynamic, re-configurable, programmable optical network. The objective of this paper is twofold: (1) provide an extensive overview tutorial of the numerous existing implementations of ADM, (2) categorize these different ADM implementations, and (3) assess their respective limitations and impacts on an evolving optical network. Toward this goal, a clear distinction between an OADM and a WADM node is made in terms of add/drop port configuration using a functional black box approach, and the types of component and device technologies that support these structures. Our second objective is to use this classification scheme to project, what we believe, is the functional form of the next generation ADM module. This is accomplished by taking into account major trends and developments in the optical networking arena. Lastly, some technical perspectives and directions toward the form of the next generation ADM are presented.

Tunable flat-top polarization interleaver filters based on cascaded film cavity structure

“…In recent years, as optical networks become more complicated, interleavers with asymmetrical output spectra have received much attention [2][3] . Several techniques have been proposed to implement asymmetrical interleavers.…”