Abstract: A non-contact optical probe utilizes an optical reference surface that projects a curved test wavefront toward the test surface and detects it by creating curved interferometric fringes localized in space in front of the reference surface. When a point to be measured on the test surface intersects the location of the fringes, the condition is detected by the probe. Because the fringes are localized at a known position in space with respect to a reference system, the precise coordinate of the surface point can be established. Such localized fringes are preferably produced by a spectrally controllable light source. The curvature of the fringes ensures a sufficiently large angle of acceptance for the probe to capture light reflected from points of high surface slope. The probe is particularly suitable for coordinate measurement machines.

Abstract: A non-contact optical probe utilizes an optical reference surface that projects a curved test wavefront toward the test surface and detects it by creating curved interferometric fringes localized in space in front of the reference surface. When a point to be measured on the test surface intersects the location of the fringes, the condition is detected by the probe. Because the fringes are localized at a known position in space with respect to a reference system, the precise coordinate of the surface point can be established. Such localized fringes are preferably produced by a spectrally controllable light source. The curvature of the fringes ensures a sufficiently large angle of acceptance for the probe to capture light reflected from points of high surface slope. The probe is particularly suitable for coordinate measurement machines.

Abstract: A non-contact metrology system utilizes a display that can be programmed with a plurality of targets. The display targets shine on a specular surface and the reflected targets are detected by an imaging device. Based on the display pattern and the expected location of the reflected pattern, it is possible to characterize the reflective surface. The displayed pattern can be a regular array of targets and the reflected pattern detected by the imaging device is an irregular display of targets whose locations are based on the particular display pattern, the location of the display system and imaging device and the nature of the surface. Deviations of the actual location of targets from the expected location of targets is indicative of unexpected variations in the surface. Alternatively, the display has an irregular pattern of targets such that the reflected signals result in a regularly spaced array detected by the imaging device.

Abstract: A non-contact metrology system utilizes a display that can be programmed with a plurality of targets. The display targets shine on a specular surface and the reflected targets are detected by an imaging device. Based on the display pattern and the expected location of the reflected pattern, it is possible to characterize the reflective surface. The displayed pattern can be a regular array of targets and the reflected pattern detected by the imaging device is an irregular display of targets whose locations are based on the particular display pattern, the location of the display system and imaging device and the nature of the surface. Deviations of the actual location of targets from the expected location of targets is indicative of unexpected variations in the surface. Alternatively, the display has an irregular pattern of targets such that the reflected signals result in a regularly spaced array detected by the imaging device.

Abstract: Apparatus and methods for generating an empirically determined mathematical model of wavefront error in an interferometer as a function of aperture misalignment and then applying the model to correct subsequent measurements. The methods are useful in Fizeau and other types of interferometers in which carrier fringe analysis may be used for reducing errors caused by environmental and vibration effects.

Abstract: A device for destroying microbes in a fluid medium utilizing a housing. The housing possesses an exterior and a fluid passageway formed by an inner wall portion. The housing also includes a plurality of chambers positioned radially outwardly from the fluid passageway. The chambers and enclose magnets which surround the passageway. First and second electrodes extend along the fluid passageway and lie flush with the inner wall portion. The electrodes include terminals that are available on the exterior of the housing to receive power from a source.

Abstract: Apparatus and methods for generating an empirically determined mathematical model of wavefront error in an interferometer as a function of aperture misalignment and then applying the model to correct subsequent measurements. The methods are useful in Fizeau and other types of interferometers in which carrier fringe analysis may be used for reducing errors caused by environmental and vibration effects.

Abstract: Apparatus and means for calibrating optical gap-measuring instruments, including a preferred calibration standard (100) comprised of a substantially flat, transparent element (10) held in contact with the convex spherical surface (25) of a substantially opaque element (20) to provide an obvious and unambiguous region over which the gap is zero. The optical gap measuring tool that is to be calibrated is oriented so as to illuminate the interface. The calibration standard (100) is translated in position with respect the gap measuring tool in such a way as to vary the measured gap, while at the same time data storage means record the gap measurement as a function of relative position. This data is then compared to the predicted variation from the geometry of the calibration standard (100). Provided that the elements (10, 20) are of high optical quality, deviations of the measured data from an ideal parabolic curve are indicative of calibration errors.

Abstract: A linear measurement interferometer 10 with a measurement axis directed toward a surface of a work piece 17 has a light source 11, a detection system 12, and a beam splitter 13 arranged to divide light from the source into test beams 21, 22, and 34 and reference beams 23, 24, and 33 that travel test and reference paths and recombine for detection by the detection system. Beam splitter 13 is arranged on the measurement axis with the work piece surface on one side of the beam splitter and the test beam path straddling the measurement axis on the opposite side of the beam splitter. A test beam retroreflector 25 mounted in the test path on the measurement axis reflects back the test beam from beam splitter 13 and is movable along the measurement axis without causing abbe error.