Abstract: A wave front sensor having a focusing optical system (1), a perforated diaphragm (2) with a plurality of perforations (21) situated simultaneously in the beam path (3), in an encoded arrangement, in particular according to and a cyclic Hadamard code, a device (22) for advancing the perforated diaphragm (2), so that a multiplicity of different encoded arrangements of perforations (21) are situated successively in the beam path (3).

Abstract: Process and apparatus for testing optical components (12) or systems which are contained in an apparatus consisting of a focusing optical system (1) and a space-resolving light detector (2) close to the focal plane thereof, it being provided that a source (3), containing a collimator (32), for a narrowly delimited precisely parallel light beam with a plane wavefront is moved rectilinearly in a plane parallel to the wavefront, at a plurality of positions of the source (3) the signal of the light detector (2) is determined, tilting movements of the source (3) perpendicular to the line direction are detected by an apparatus with a second collimator (52) and space-sensitive detector (51), and the aperture of the optical system (1) is scanned twice with line directions rotated relative to one another through approximately 90.degree., and in addition an individual line coming close to the axis of rotation is scanned in a position rotated through approximately 45.degree..