A method for generating M demodulation signals is disclosed. In one aspect, the method includes: providing M input signals, injecting each input signal into at least one first interferometer, and detecting M demodulation signals. The method also includes choosing M positive integers that are not all equal to zero and computing M demodulation signals. The ith demodulation signal being the product of Ri+1 functions, Ri being the chosen integer that corresponds to the first delay of the ith first interferometer, and the pth function being equal to St,p(t)=S(t=pτi), where p is an integer between 0 and Ri, τi is the first delay introduced by the delay line of the ith first interferometer, and S is a transform of the signal at the output of the ith first interferometer.