Abstract: An optical method and system for measuring three-dimensional surface topography by providing high resolution contour measurements of an object using interferometric methods. The invention utilizes co-sight detector technology to provide at least three independent images of exactly the same object location, with a known fringe pattern optically introduced to each of the images. Each of the fringe patterns have a known phase difference relative to the phase appearing on each of the other images. Furthermore, the images have the same perspective relative to the object and may be collected simultaneously. This simultaneous collection of multiple phase images allows very high speed 3D data generation. Previous limitations of phase shift technology such as sample motion and vibration can be eliminated. The method may use continuous or strobed illumination.

Abstract: A method is provided for calibrating a tilt inspection system and a reference disk assembly for use therein wherein a mirror disk of the assembly is attached to a rotatable member of the system by a beveled washer so that the mirror disk rotates at a predetermined tilt angle with respect to an axis of rotation of the rotatable member. As the reference disk assembly is rotated by the tilt inspection system at a relatively slow and constant angular velocity, a beam of light is reflected off the mirror disk to a position sensitive detector (i.e., PSD) and subscribes a circle on the face of the PSD. The tilt inspection system samples the channels from the PSD throughout one revolution of the mirror disk. Calibration or reference data is calculated in the form of tilt transformations.

Abstract: A method and system are provided for measuring a two-dimensional deflection angle of a beam of light reflected from a disk having unknown radial and tangential tilt components by first generating reference data relating to known tilt of a reference disk and then processing the reference data with electrical signals from a two-dimensional photodetector to obtain values related to the deflection angle and the unknown radial and tangential tilt components. The photodetector is preferably a semiconductor photodiode having an active area which measures position of radiant energy in a spot of light focused in a detector plane by a focusing lens. A signal processor including a computer system programmed in accordance with a software algorithm compensates for interaction between X and Y axes of the active area of the photodiode to compensate for alignment errors or tolerances, not only up, down, left and right, but also for rotational errors as well.