Abstract: A method for measuring the contours (30) of a three-dimensional object (4); and a method for calibrating an optical system (2, 8). The object (4) is placed into the field of view of the optical system (2, 8). The optical system (2, 8) is activated to obtain a set of data giving a phase (x.sub.t) at each of a plurality of pixels corresponding to the object (4). The phases (x.sub.t) are unwrapped, e.g., by a method of ordered phase unwrapping. The unwrapped phases are converted into a set of three-dimensional coordinates (x.sub.s, y.sub.s, z.sub.s) of the object (4) for each of the pixels. These coordinates (x.sub.s, y.sub.s, z.sub.s) can be portrayed on a display of a computer (10). The method for calibrating the optical system (2, 8) shares several common steps with the above method. In addition, coordinates of a test calibration fixture (38, 46) are first mechanically measured.

Abstract: A method for measuring the contours (30) of a three-dimensional object (4); and a method for calibrating an optical system (2, 8). The object (4) is placed into the field of view of the optical system (2, 8). The optical system (2, 8) is activated to obtain a set of data giving a phase (x.sub.t) at each of a plurality of pixels corresponding to the object (4). The phases (x.sub.t) are unwrapped, e.g., by a method of ordered phase unwrapping. The unwrapped phases are converted into a set of three-dimensional coordinates (x.sub.s, y.sub.s, z.sub.s) of the object (4) for each of the pixels. These coordinates (x.sub.s, y.sub.s, z.sub.s) can be portrayed on a display of a computer (10). The method for calibrating the optical system (2, 8) shares several common steps with the above method. In addition, coordinates of a test calibration fixture (38, 46) are first mechanically measured.

Abstract: A real-time radial shear interferometer for monitoring the quality of the wavefront of an optical beam comprises (with reference to FIG. 3) a pair of beamsplitters (40, 45) and a pair of beam-folding mirrors (44, 46) arranged in Mach-Zehnder format. An afocal telescope (41) and a diffraction grating (30) cause a transmitted component of the beam to be separated into a plurality of diffraction maxima, and an afocal telescope (47) and a diffraction grating (31) cause a reflected component of the beam to be separated into a plurality of diffraction maxima. Diffraction beams formed from the transmitted component of the beam are combined with corresponding diffraction beams formed from the reflected component of the beam to produce a zeroth-order interferogram and positive and negative first-order interferograms.

Abstract: A real-time diffraction interferometer for analyzing an optical beam comprises converging means (13) for bringing the beam to a focus at focal point (14), and an apertured grating structure (20) positionable adjacent the focal point (14). The apertured grating structure (20) comprises a transparent substrate (10'), an obverse surface of which is coated with a translucent coating (11) except for a pinhole-sized spot (12) that is left uncoated so as to function as an aperture in the coating (11). A reverse surface of the substrate (10') has a lenticulate surface configuration, which functions as a diffraction grating. The beam incident upon the apertured grating structure (20) is separated into a major portion, which is transmitted with attenuated intensity through the translucent coating (11), and a minor portion, which is transmitted with undiminished intensity through the pinhole aperture (12).