Wavefront sensor based on interference, comprising; - an optical input, intended to receive a light radiation having an initial wavefront (S 0) that extends through said optical input; - a radiation splitter, arranged in order to produce, from light beams (F 1, F 2) that originate respectively from restricted zones within the optical input, at least two sub-beams (F' 1, F" 1, F' 2, F" 2) for each light beam, each sub-beam reproducing characteristics of the initial wavefront (S 0) existing in the corresponding restricted zone; - optical paths, arranged in order to superimpose two sub-beams (F" 1, F' 2) that originate respectively from two different restricted zones within the optical input, and which each pass via a different optical path; - at least one image detector, arranged in order to capture interference patterns that are produced by the superimposed sub-beams (F" 1, F' 2); - a processing module, suitable for determining, from the interference patterns, differences in piston (p) and tilt (i) existing for the initial wavefront (S 0) between the restricted zones from which the superimposed sub-beams originate; and - a mask suitable for selecting, by means of openings in said mask, disjoint zones of interest within the optical input as restricted zones, by at least partially blocking the initial wavefront (S 0) outside said zones of interest, or by at least partially blocking light beams that do not originate from said zones of interest, so that separate portions of the image detector are dedicated respectively to pairs of zones of interest that are neighbouring within the optical input, characterized in that the mask and the radiation splitter are formed together by a spatial light modulator. - an optical input, intended to receive a light radiation having an initial wavefront (S 0) that extends through said optical input; - a radiation splitter, arranged in order to produce, from light beams (F 1, F 2) that originate respectively from restricted zones within the optical input, at least two sub-beams (F' 1, F" 1, F' 2, F" 2) for each light beam, each sub-beam reproducing characteristics of the initial wavefront (S 0) existing in the corresponding restricted zone; - optical paths, arranged in order to superimpose two sub-beams (F" 1, F' 2) that originate respectively from two different restricted zones within the optical input, and which each pass via a different optical path; - at least one image detector, arranged in order to capture interference patterns that are produced by the superimposed sub-beams (F" 1, F' 2); - a processing module, suitable for determining, from the interference patterns, differences in piston (p) and tilt (i) existing for the initial wavefront (S 0) between the restricted zones from which the superimposed sub-beams originate; and - a mask suitable for selecting, by means of openings in said mask, disjoint zones of interest within the optical input as restricted zones, by at least partially blocking the initial wavefront (S 0) outside said zones of interest, or by at least partially blocking light beams that do not originate from said zones of interest, so that separate portions of the image detector are dedicated respectively to pairs of zones of interest that are neighbouring within the optical input,