Abstract: A computer generated phase map and corresponding set of interference fringes calculated from a theoretical prescription of a measured aspheric surface comprises a Computer Generated Reference (CGR) that is used in an interferometer equipped with a spherical and/or flat reference element. moiré fringes created between real interference fringes and the CGR describe the difference between the measured object and its prescription. The moiré fringes can be nulled making the measurement of the aspheric surface analogous to the measurements of the regular spherical and/or flat surfaces.

Abstract: A simultaneous phase-shifting white light scanning interferometer comprises a white light scanning interferometer, a simultaneous phase-shifting module, and a scanner. Light from a short coherence length light source may be polarized and then split, by a polarization type beam-splitter, into orthogonally polarized reference and test beams. The simultaneous phase-shifting module comprises a plurality of detectors, allows for controlled phase shifts between the reference and test beams, and creates at least three independent interferograms, each with different phase shifts between the reference and test beams. The scanner translates the simultaneous phase-shifting module with respect to an object under measurement.

Abstract: An optical measuring apparatus for measuring 3D surface profiles of an object comprising, in combination: a linear detector array; an imaging system including a light source to image the object onto the detector array; and machine readable software for producing a 3D topology map from a 2D image, wherein the apparatus is calibrated by changing the optical focus distance between the detector array and the object for the purpose of 3D measurement calibration, and changing the relative lateral positions between the detector array and the object for the purpose of scanning the object's surface.

Abstract: An optical measuring apparatus for comprising, in combination, a polarization type interferometer including a polarization type beam splitter in which a polarized beam of light is split into orthogonally polarized reference and test beams, an array of detectors arranged in a line for creating a plurality of phase shifting interferograms, and a scanning device for moving the object in a direction perpendicular to a long axis of the detectors.

Abstract: A lateral-shear interferometer utilizes two relatively thick glass plates bonded together in a single block with a tilted air gap between opposing inner surfaces. The thickness of the glass plates is selected to be sufficiently large to separate the output beams from the light reflected from the top and bottom surfaces of the block, thereby eliminating the need for antireflection coatings. The shear interferometer is combined with an external mirror mounted on a tilt stage actuated by a computer-controlled tilt actuator to perform phase-shifting interferometric analysis in conventional manner.