Abstract

Optical Add-Drop Multiplexers (OADM) are key devices for the development of Wavelength Division Multiplexing (WDM) fibre optic networks [1]. The OADM allows, in the optical domain, to extract one channel (Drop function) from a WDM transmission link and to insert another one (Add function), at the same wavelength, carrying new information. A critical feature of an OADM is the isolation between Add and Drop ports since even a low level of leakage (< -25 dB) of the inserted channel into the Drop port generates homo-wavelength interference with the extracted channel, leading to unacceptable degradations of the transmission performance [2]. In this paper we report the proposal and realisation of a new structure of OADM [3] optimised with respect to the isolation features and the tuneability.

© 1996 IEEE