Patent ID: 6285810
Filing Date: 2001-09-04
Classification: G02F

Abstract:
Tunable add/drop optical device adapted to handle wavelength division multiplexed (WDM) signals, for injecting or extracting (add/drop) at least a selected optical channel or carrier wavelength in or from a set of multiplexed channels or carriers of different wavelength, comprising a plurality of directional couplers and a plurality of phase-shift stages, alternately connected in cascade, wherein each phase-shift stage defines a certain optical path length difference between two distinct optical paths of the stage, causing a periodic response characteristic with a spectral separation between two adjacent peaks of said periodic response characteristic sufficient to contain all deselected wavelengths of said multiplexed channels when a peak of the periodic response characteristic is centered on a selected wavelength, characterized in thatthe optical medium constituting one of said two distinct optical paths of each of said phase-shift stages has a refraction index dependent from a physical parameter belonging to the group composed of temperature and electric field intensity and the device includes bias means for controllably varying said parameter.