Optical component of the waveguide array spectrograph type, having centered outlet channels

An optical component of the waveguide array spectrograph type, the component comprising an inlet coupler and an outlet coupler between which said array extends, and including inlet and outlet optical channels connected to the inlet and outlet couplers, suitable for multiplexing and/or demultiplexing two optical signals of different wavelengths conveyed by two channels of the same coupler, wherein the waveguides of the array have lengths that are distributed in such a manner that two free spectrum ranges having different center wavelengths both occur in said same coupler, said different wavelengths conveyed by the two channels each belonging to a different free spectrum range, and each of the two wavelengths conveyed by a channel belonging to that one of the free spectrum ranges whose center wavelength is the closer of the two center wavelengths to the wavelength conveyed by the channel.