Optical component for monitoring a multi wavelength connection and add drop multiplexer using this component, application to optical networks

The component includes an input optical fibre (68) which carries N different wavelength signals. A diffraction grating is a plane blazed grating (70), preferably in Littrow configuration. It is blazed in the first order and a set of fibres (72,74,76,78) recovers the signals corresponding to the first order diffraction. A set of control fibres (79,80,82,84) recovers the signal from a second or higher order diffraction. A first optical component may be used to separate the wavelengths and to extract one of the signals while a second component mixes the signals except that extracted which is replaced by another signal at that wavelength. Ce composant comprend une fibre (68) transmettant des signaux de longueurs d'onde différentes, un réseau de diffraction (70) dispersant ces signaux sur plusieurs ordres de diffraction, des fibres (72 à 78) récupérant des signaux ainsi dispersés, correspondant à un ordre de diffraction donné, et des fibres (79 à 84) récupérant les mêmes signaux mais correspondant à un autre ordre de diffraction, pour contrôler l'état de ces signaux.