A device is provided for processing a light/optical radiation including at least two reflective optical elements defining a multi-pass cavity so that at least one of the optical elements reflects the light radiation at least twice, at at least two different reflection positions, and including at least one element, called a corrective element, having at least one position, called a corrective position, producing a reflection or a transmission of the optical radiation, and the surface of which is irregular so that the spatial phase profile of the corrective position has a different phase shift for several different reflection/transmission points of the corrective position.