Abstract: A method and system is disclosed for utilizing two single-shot phase shift interferometers to simultaneously measure wafer shape and thickness variation of two sides of a wafer. This system is able to extract the front height, the back height, and the thickness variation of a wafer in a single data acquisition. This system, when utilized with a fast shutter speed, decreases the insensitivity to vibration. Algorithms are introduced that extract the true thickness variation of a wafer even when the wafer is vibrating. The effects of air turbulence can be reduced by a phase averaging technique.

Abstract: The present invention provides a measurement apparatus which measures a measurement surface based on an interference signal obtained by causing measurement light reflected by the measurement surface and reference light reflected by a reference surface to interfere with each other, the apparatus including an interference optical system including a lens for focusing the measurement light to be incident on the measurement surface, and configured to cause the measurement light and the reference light to interfere with each other, and an adjusting device configured to adjust a focusing state of the measurement light focused by the lens such that a measurement point on the measurement surface positions within a range of a depth of focus of the lens, wherein the interference signal is obtained with the focusing state adjusted by the adjusting device.

Abstract: A frequency-shifting interferometer is arranged for measuring an optical profile of a test object with a continuously tunable light source. A succession of the interference images of the test object are captured together with a measure of the beam frequencies at which interference images are formed. A limited number of the captured interference images of the test object are selected so that the monitored beam frequencies approximately match a predetermined beam frequency spacing pattern. Further processing proceeds based on the selected interference images.

Abstract: A measurement apparatus includes: a vibration detection surface which has a set relative position with respect to a test surface, and is irradiated with a part of the measurement light; an image sensor configured to sense, together with a first interference fringe generated by interference between reference light from a reference surface and measurement light from the test surface, a second interference fringe generated by interference between light from the vibration detection surface and the reference light; and a processor configured to obtain a relative vibration between the reference surface and the test surface by using data of the sensed second interference fringe, and obtain the shape of the test surface by using the obtained relative vibration and data of the sensed first interference fringe.

Abstract: A Fizeau interferometer incorporates an off-axis paraboloidal reflector that forms virtual images of reference and test surfaces and a camera lens that converts the virtual images into real images on a camera detector surface. The camera detector surface is arranged together with the camera lens to accommodate tilting of the virtual images by the off-axis paraboloidal reflector.

Abstract: A shape measuring apparatus includes: an optical system configured to guide a light from a light source having a wideband spectrum to an object to be measured and a reference face; an imaging unit configured to image the interfering light intensity distribution image output from the optical system; an optical path length difference changing unit configured to change the optical path length difference; and an arithmetic processing unit configured to obtain the peak value of an interfering light intensity sequence indicating the change in the interfering light intensity due to the change in the optical path length difference at each measurement position of the interfering light intensity distribution images stored in the image storing unit, and configured to obtain the peak value as the position in the direction of the optical axis at each measurement position of the object to be measured.

Abstract: The present invention provides a measurement apparatus which measures a surface shape of a measurement target surface, the apparatus including an optical system configured to split light from a light source into measurement light and reference light, guide the measurement light onto the measurement target surface, and guide the reference light onto a reference surface, a detection unit configured to detect an intensity of the measurement light reflected by the measurement target surface, an intensity of the reference light reflected by the reference surface, and an interference pattern formed between the measurement light reflected by the measurement target surface and the reference light reflected by the reference surface, and a processing unit configured to obtain a surface shape of the measurement target surface based on an interference signal of the interference pattern detected by the detection unit.

Abstract: An optical inspection system can include an optical coherent tomography (OCT) tool having an optical column with a beam splitter optically coupled to an objective. Illumination optics are coupled to the beam splitter. An OCT focusing system is optically coupled to the objective via the beam splitter. The OCT focusing system includes a broadband light source, a reflector, a photo-detector, all of which are connected by optical fiber to a fiber coupler in an interferometer configuration. The objective is optically coupled to the fiber coupler in the OCT focusing system by an optical fiber.

Abstract: An aspheric face form measuring method calculates phase information of interference light from light intensity of a fringe pattern image obtained by detecting interference light that is formed by measurement light and reference light reflected off a subject aspheric face being overlaid. The method changes a relative distance between an optical system and the subject aspheric face and transitions a position of a null region. The method performs calculation of form data for a vertical incident region where measurement light is vertically incident to the subject aspheric face, using phase information and a scanning amount. The method performs calculations of form data, of the null regions, a non-vertical incident region that is outside of the vertical incident region. The method also composites a plurality of partial form data of the subject aspheric face previously calculated, using each of a plurality of the phase information and scanning amounts.

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: Correction factors for the ALR and PTR parameters of magnetic-head sliders are determined by calculating an effective reflectivity and a corresponding PCOR at each pixel of the air-bearing surface. The absolute value of reflectivity at each pixel of the AlTiC air-bearing surface is obtained from an empirical equation relating it to modulation. The ratio of Al2O3 and TiC in the AlTiC surface is then calculated at every pixel assuming a linear relationship between the absolute value of AlTiC reflectivity and the theoretical reflectivity of each constituent. The linear relationship is then also used to calculate the effective (complex) reflectivity for the AlTiC material from the relative concentrations of Al2O3 and TiC at each pixel.

Abstract: Described are an imaging device and method for determining three-dimensional position information of a surface of an object. The device includes a pair of optical fibers, a phase shifter, a detector array and a processor. The phase shifter is coupled to one of the optical fibers and is used to change a phase of optical radiation emitted from the optical fiber relative to a phase of optical radiation emitted from the other optical fiber. The detector array receives optical radiation scattered by the surface of the object. The processor communicates with the detector array and the phase shifter. Signals generated by the detector array are received by the processor and three-dimensional position information for the surface is calculated in response to the received optical radiation scattered by the surface of the object and the change in the relative phase of optical radiation emitted by the optical fibers.

Abstract: Phase differences associated with a defocused wavefront can be determined from a single color image. The color image, which is a measurement of intensity as a function of wavelength, is used to calculate the change in intensity with respect to wavelength over the image plane. The change in intensity can then be used to estimate a phase difference associated with the defocused wavefront using two-dimensional fast Fourier transform solvers. The phase difference can be used to infer information about objects in the path of the defocused wavefront. For example, it can be used to determine an object's shape, surface profile, or refractive index profile. It can also be used to calculate path length differences for actuating adaptive optical systems. Compared to other techniques, deriving phase from defocused color images is faster, simpler, and can be implemented using standard color filters.

Abstract: The present invention relates to a scanning microscope using an I/Q-interferometer. The scanning microscope includes an I/Q-interferometer which demodulates the phase change and amplitude change induced on the probe beam to provide the I- and Q-signals, an XY scanner, a scanner driver, a precision motion stage controlling the displacement of the sample along the direction parallel to the direction of the probe beam, a motion stage driver, a focusing/collimating device, and a computer. The computer transfers control commands to the scanner driver for scanning the XY scanner, receives I- and Q-signal provided from the I/Q-interferometer, processes the I- and Q-signal to obtain the corresponding phase and amplitude values at each scanning point, calculates error signal for maintaining constant phase during the scanning, and transfers commands to the motion stage driver for the precision motion stage to compensate for phase changes caused by surface morphology during the scanning.

Abstract: The present invention may include acquiring a wafer shape value at a plurality of points of a wafer surface at a first and second process level, generating a wafer shape change value at each of the points, generating a set of slope of shape change values at each of the points, calculating a set of process tool correctables utilizing the generated set of slope of shape change values, generating a set of slope shape change residuals (SSCRs) by calculating a slope of shape change residual value at each of the points utilizing the set of process tool correctables, defining a plurality of metric analysis regions distributed across the surface, and then generating one or more residual slope shape change metrics for each metric analysis region based on one or more SSCRs within each metric analysis region.

Abstract: A method for determining the surface topography of a coated object and for the simultaneous spatially resolved determination of the thickness of the layer on the coated object. It is provided that the surface topography is measured with the aid of white-light interferometry, the thickness of the layer is measured by the principle of reflectometry, and by using, for both measurements, a shared radiation source having an electromagnetic radiation spectrum, which is reflected from the layer surface in a first wavelength range contained in the radiation spectrum and which penetrates into the layer in a second wavelength range contained in the radiation spectrum. Also described is a corresponding optical measuring instrument. The method and the optical measuring instrument make simultaneous highly accurate surface measurement of the surface topography and of the layer thickness of coated objects possible.

Abstract: Correction factors for the ALR and PTR parameters of magnetic-head sliders are determined by calculating an effective reflectivity and a corresponding PCOR at each pixel of the air-bearing surface. The absolute value of reflectivity at each pixel of the AlTiC air-bearing surface is obtained from an empirical equation relating it to modulation. The ratio of Al2O3 and TiC in the AlTiC surface is then calculated at every pixel assuming a linear relationship between the absolute value of AlTiC reflectivity and the theoretical reflectivity of each constituent. The linear relationship is then also used to calculate the effective (complex) reflectivity for the AlTiC material from the relative concentrations of Al2O3 and TiC at each pixel.

Abstract: The present surface shape measurement method includes: splitting white light that includes different wavelengths into reference light and measurement light; causing the measurement light to enter a measurement target plane; causing the reference light to enter a first diffraction grating; combining the reference light having passed through a first optical path from the first diffraction grating to enter a second diffraction grating and thereafter having passed through the first optical path from the second diffraction grating to enter the first diffraction grating to be output from the first diffraction grating and the measurement light reflected from the measurement target plane, to form interfering light, to thereby measure a surface shape of the measurement target plane.

Abstract: An interferometer that measures a shape of a surface of an inspection object includes an interference optical system that splits light from a light source into inspection light and reference light and causes the inspection light reflected by the surface of the inspection object and the reference light to interfere with each other, and a photoelectric conversion element that detects interference fringes produced by interference between the inspection light and the reference light. The interference optical system includes a first optical element that transmits and reflects the inspection light, a second optical element that reflects the inspection light, and a moving unit configured to move the second optical element. The inspection light passes through the first optical element, is reflected by the second optical element, is reflected by the first optical element, and is then incident on the surface of the inspection object.

Abstract: In-situ calibration of an interferometer includes making a sequence of phase measurements of a test object using the interferometer, each of the measurements having a same carrier fringe frequency, where at least some of the measurements are made at three or more different orientations of carrier fringes, and determining information about the test object based on at least some of the phase measurements, in which determining the information includes reducing errors in the measurements arising from imperfections in the interferometer based on the measurements made at the three or more different orientations.

Abstract: Described are a method and device for determining three-dimensional position information of a surface of a translucent object having a wavelength-dependent transmittance and reflectance characteristics. The method includes illuminating the surface of the translucent object with optical radiation at a predetermined wavelength emitted from a pair of optical sources. Radiation scattered from the surface and below the surface is detected, and a phase of the optical radiation from one of the optical sources relative to a phase of the optical radiation from the other optical source is changed before again detecting the scattered radiation. The predetermined wavelength is selected so that the optical radiation scattered from below the surface and detected provides a substantially constant background intensity with respect to the optical radiation scattered from the surface and detected. Three-dimensional position information of the surface is calculated in response to the detected radiation.

Abstract: A non-energy dissipating, curvature sensing device senses curvature variation of a sample and comprises an outer layer, an inner layer and at least one spacer. The outer layer is flexible, transparent material and has a shape. The inner layer is flexible, transparent material, has a shape corresponding to the shape of the outer layer, is positioned under the outer layer and is thicker and harder than the outer layer. At least one spacer is positioned between the outer layer and the inner layer and creates space between the outer layer and the inner layer. A non-energy dissipating, curvature sensing method is also disclosed.

Abstract: A landed dot measuring method in which a topology measuring apparatus having an interferometer measures topology of a landed dot which is a functional liquid droplet landed on an inspection sheet when an inspection ejection for a functional liquid droplet ejection head is performed including: inspection-ejecting in which multiple ejection nozzles of a functional liquid droplet ejection head inspection-eject one by one at a time interval while the functional liquid droplet ejection head is moved in a main scanning direction relatively with respect to the inspection sheet and; and measuring in which respective topologies of multiple landed dots are measured while the topology measuring apparatus follows the functional liquid droplet ejection head and moves in the main scanning direction at a same speed as the functional liquid droplet ejection head relatively with respect to the inspection sheet.

Abstract: There is a situation in that, although a speckle interference optical system is effective for clarification of a process of deformation of a specimen, resolution is insufficient, and execution of a phase shift method for improving the resolution involves a costly apparatus. A phase shift image for an initial fringe pattern is acquired, and a phase variation between phase information on an initial image and a next image is derived by a phase shift method. After that, a phase shift image for the next image is computed by calculation based on the acquired information.

Abstract: Provided is an optical tomographic imaging apparatus which enables simplification and cost reduction without reducing accuracy when moving part of an object is moved in an optical axis direction of measuring beam. The apparatus using return beam of measuring beam reflected or scattered by an object and reference beam reflected by a reference mirror to image the tomographic image, includes: a reflecting position controlling device for controlling the reflecting position of the reference mirror; a detecting device for a position in a moving part having an optical system for observing the moving part illuminated by an optical system imaging the same on an area sensor based on the Scheimpflug principle and detects position information that the moving part is moved in the direction; and a device for driving the reflecting position controlling device to control the optical path length of the reference beam based on the position information.

Abstract: The present invention provides a method of measuring a shape of a target surface, including a step of obtaining shape data by causing a stage which holds the target surface to rotate the target surface about a rotation axis, positioning each of a plurality of partial regions of the target surface in a field of view of a measurement apparatus, and causing the measurement apparatus to measure each of the plurality of partial regions, a step of obtaining, for each of a plurality of partial contour regions, a central position of the target surface using data of a contour included in the shape data, and a step of obtaining, based on the obtained plurality of central positions, a position of the rotation axis of the target surface in positioning each of the plurality of partial regions.

Abstract: Systems configured to generate output corresponding to defects on a specimen and systems configured to generate phase information about defects on a specimen are provided. One system includes an optical subsystem that is configured to create interference between a test beam and a reference beam. The test beam and the reference beam are reflected from the specimen. The system also includes a detector that is configured to generate output representative of the interference between the test and reference beams. The interference increases contrast between the output corresponding to the defects and output corresponding to non-defective portions of the specimen.

Abstract: A digitized image of an object may include representations of portions of the object that are obscured, occluded or otherwise unobservable. The image may be a multi-dimensional visual representation of dentition. Characteristics of the dentition and its surfaces, contours, and shape may be determined and/or analyzed. A light may be directed toward and reflected from the dentition. The reflected light may be combined with a reference to determine characteristics of the dentition, including obscured areas such as subgingival tissue.

Abstract: A method of measuring a deviation of an optical surface from a target shape and a method of manufacturing an optical element. The method of measuring the deviation includes:—performing a first interferometric measurement using a first diffractive measurement structure, which is arranged to cover a first area of the optical surface, to provide a first interferometric measurement result,—performing a second interferometric measurement using a second diffractive measurement structure, which is arranged to cover a second area of the optical surface different from the first area, to provide a second interferometric measurement result, and—determining a deviation of the optical surface from the target shape.

Abstract: A method for measuring a surface profile of an object, the method includes, acquiring information about a first direction where a step of a surface of the object extends relative to a scanning direction, setting phase distribution applied to the irradiation beam according to the information, and scanning the object in the scanning direction with the irradiation beam.

Abstract: The present invention provides a measurement apparatus which measures a height of a surface to be measured, including a detection unit configured by two-dimensionally arraying a plurality of regions where an intensity of interference light between reference light and measurement light is detected, a first optical system configured to split light emitted by a light source into first light and second light, a generation unit configured to receive the first light, and generate, from the first light, the reference light including a plurality of reference beams having optical path length differences in two directions perpendicular to each other in cross section surface, and a second optical system configured to cause the reference light to reach the detection unit so as to cause the respective reference beams generated by the generation unit to reach the corresponding regions.

Abstract: The present invention provides a reference standard used to calibrate measurement data of a measuring device for measuring the shape of a measurement surface utilizing interference between light from the measurement surface and light from the reference surface. A measurement surface of the reference standard has at least one protruding mark and one recessed mark, and an integrated value of the dimension of the protruding mark in the direction normal to the measurement surface of the reference standard, on the circumference of an assumed circle on the measurement surface centered at a point on an optical axis of the reference standard, is equal to an integrated value of the dimension of the recessed mark in the direction normal to the measurement surface of the reference standard on the circumference of the assumed circle.

Abstract: The measurement accuracy of an apparatus for measuring the surface shape of an object utilizing a two-wavelength phase-shift interferometry is improved. A low-coherence light source, a plurality of wavelength filters with different transmission wavelengths, an angle control unit and an analysis unit are provided. When performing a two-wavelength phase shift method, the analysis unit detects the wavelength difference between two wavelengths, and corrects a calculated wavelength value and a calculated phase value of one of the wavelengths for preventing a fringe-order calculation error. Next, the angle of the wavelength filters is controlled for making the actual wavelength difference coincident with a designed value. Thus, the wavelength difference between the two wavelengths is continuously controlled to be constant, which enables measurements of surface shapes with high accuracy, even when there are wavelength fluctuations due to the temperature change or the time elapse.

Abstract: Correction factors for the ALR and PTR parameters of magnetic-head sliders are determined by calculating an effective reflectivity and a corresponding PCOR at each pixel of the air-bearing surface. The absolute value of reflectivity at each pixel of the AlTiC air-bearing surface is obtained from an empirical equation relating it to modulation. The ratio of Al2O3 and TiC in the AlTiC surface is then calculated at every pixel assuming a linear relationship between the absolute value of AlTiC reflectivity and the theoretical reflectivity of each constituent. The linear relationship is then also used to calculate the effective (complex) reflectivity for the AlTiC material from the relative concentrations of Al2O3 and TiC at each pixel.

Abstract: Correction factors for the ALR and PTR parameters of magnetic-head sliders are determined by calculating an effective reflectivity and a corresponding PCOR at each pixel of the air-bearing surface. The absolute value of reflectivity at each pixel of the AlTiC air-bearing surface is obtained from an empirical equation relating it to modulation. The ratio of Al2O3 and TiC in the AlTiC surface is then calculated at every pixel assuming a linear relationship between the absolute value of AlTiC reflectivity and the theoretical reflectivity of each constituent. The linear relationship is then also used to calculate the effective (complex) reflectivity for the AlTiC material from the relative concentrations of Al2O3 and TiC at each pixel.

Abstract: A shape measurement apparatus and method using a laser interferometer are disclosed. The shape measurement apparatus includes a plurality of laser devices, which generate beams, emit a beam of a specific frequency from among the generated beams, and output interference signals for detecting wavelengths of the generated beams, and a controller for detecting the wavelengths of the generated beams from the outputted interference signals, and controlling the laser devices on the basis of the detected wavelengths. The optical unit projects the beam of the laser device on a target object, and generates an interference pattern of the object. Several shutters are closed and opened. If the shutters are closed, they prevent the beam of each laser device to be projected on the optical unit. An image pickup unit captures the interference pattern.

Abstract: A method for calculating a shape includes dividing an aspherical test surface into a plurality of measurement regions configured to overlap with one another, receiving, at a light receiving unit, interference fringes which occur due to interference light generated by light reflected on a reference surface serving as a reference for calculating a shape of the test surface and light reflected by each of the measurement regions, and calculating surface shapes of the measurement regions, and calculating a shape of the test surface by joining the calculated surface shapes, wherein the calculation of surface shapes includes adjusting relative positions of the test surface and the reference surface and adjusting a position of the light receiving unit so that the test surface and the light receiving unit have a conjugate relationship with each other in a state in which the position of the test surface is adjusted.

Abstract: An adaptive algorithm is tailored to fit the local fringe frequency of single-frame spatial-carrier data under analysis. Each set of data points used sequentially by the algorithm is first processed with a Fourier Transform to find the local frequency of the fringes being analyzed. That information is then used to adapt the algorithm to the correct phase step thus calculated, thereby optimizing the efficiency and precision with which the algorithm profiles the local surface area. As a result, defects are identified and measured with precision even when the slope of the surface varies locally to the point where the algorithm without adaptive modification would not be effective to measure them. Once so identified, the defects may be measured again locally with greater accuracy by conventional temporal PSI.

Abstract: The surface shape measuring system includes an illumination unit including a main light source, a focusing lens, and a projection lens; a beam splitter to split illumination light emitted respectively irradiated onto a reference surface and a measurement surface; a light detecting element to capture an interference pattern; and a control computer to obtain surface shape data through white-light interference pattern analysis from an image captured and detect whether or not the measurement surface is defective from the obtained data, wherein a subsidiary light source to provide falling illumination to the target object; and two-dimensional data and three-dimensional data regarding the surface shape of the target object are obtained by selectively intermitting the turning-on of the main light source and the subsidiary light source and the irradiation of the illumination light onto the reference surface.

Abstract: An apparatus for measuring a shape of a surface comprises: a measurement head including a division unit that divides light into reference light and test light, a reference surface, a light-condensing unit that condenses the test light onto the surface, and a first detector that detects interfering light between the test light Cat's Eye-reflected by the surface and the reference light reflected by the reference surface; a driving unit that drives the measurement head along the surface; a second detector that detects a position of the measurement head; and a processor that obtains a Gouy phase generated by diffraction of the test light on the surface, calculates a phase difference between the test light and the reference light based on information of the detected interfering light, and calculates the shape of the surface from the detected position of the measurement head, the obtained Gouy phase, and the calculated phase difference.

Abstract: Methods and systems for measuring a surface of an object are provided, wherein portions of the surface of the object are interferometrically measured and data representing a shape of the surface of the object are obtained by stitching the measurement data corresponding to each portion together. For measuring the individual portions of the surface of the object a variable light shaping member is utilized preferably constructed by arranging two diffraction gratings in a beam path of measuring light and appropriately displacing the two diffraction gratings relative to each other depending on a target shape of a particular portion of the surface of the object.

Abstract: A coherence scanning interferometer carries out: a coherence scanning measurement operation on a surface area using a low numeric aperture objective so that the pitch of the surface structure elements is less that the spread of the point spread function at the surface to obtain structure surface intensity data; and a coherence scanning measurement operation on a non-structure surface area to obtain non-structure surface intensity data. A frequency transform ratio determiner determines a frequency transform ratio related to the ratio between the structure surface intensity data and the non-structure surface intensity data. A structure provider sets that frequency transform ratio equal to an expression representing the electric field at the image plane of the interferometer in terms of surface structure element size (height or depth) and width-to-pitch ratio and derives the surface structure element size and width-to-pitch ratio using the frequency transform ratio.

Abstract: Interferometric path length measurements using frequency-domain interferometry form the basis of several measurement techniques, including optical frequency domain reflectometry (OFDR), optical coherence tomography (OCT), and frequency-modulated continuous wave (FMCW) radar and lidar. A phase-sensitive and self-referenced approach to frequency-domain interferometry yields absolute and relative path length measurements with axial precision orders of magnitude better than the transform-limited axial resolution of the system.

Abstract: The present invention provides a measuring apparatus which measures a shape of a surface of a measurement target object, comprising a light projecting optical system configured to split light from a light source into measurement light and reference light so that the measurement light enters the surface of the measurement target object and the reference light enters a reference mirror, a light receiving optical system configured to guide the measurement light reflected by the surface of the measurement target object and the reference light reflected by the reference mirror to a photoelectric conversion device, and a processing unit configured to calculate the shape of the surface of the measurement target object based on an interference pattern which is detected by the photoelectric conversion device and formed by the measurement light and the reference light.

Abstract: The invention concerns a confocal microscope for imaging a sample comprising at least a light source, said microscope comprising at least an objective and a tube lens with an image focus, said microscope comprising interference means constructed to generate interference figures from said light source, characterized in that said interference means comprising first image generation means constructed to generate a first image of said light source, second image generation means constructed to generate a second image of said light source symmetrical to the first image relative to the image focus, image interference means constructed to make said first image and said second image interfere.

Abstract: Light reflected by a sample surface region and a reference surface interfere. A detector senses light intensity at intervals during relative movement along a scan path between the sample surface and the reference surface to provide a series of intensity values representing interference fringes. A data processor receives first intensity data comprising a first series of intensity values resulting from a measurement operation on a surface area of a substrate and second intensity data comprising a second series of intensity values resulting from a measurement operation on a surface area of a thin film structure. A gain is determined for each thin film of the thin film structure. Substrate and apparent thin film structure surface characteristics are determined on the basis of the first and second intensity data, respectively. The apparent thin film structure surface characteristic is modified using the substrate surface characteristic and the determined gain or gains.

Abstract: An apparatus for the absolute measurement of a two dimensional optical path distribution comprising: a light source (4) for illuminating an object (26) with light having a plurality of wavelengths: an interferometer (12) for forming an image of at least part of the object, which image comprises a broad band interferogram; a hyperspectral imager (30) in optical communication with the interferometer for spectrally separating the broad band interferogram into a plurality of narrow band two dimensional interferograms (72, 74, 76); a register (38) for spatially registering the narrow band interferograms; an extractor for extracting one dimensional intensity signals from corresponding pixels in each narrow band interferogram; and a calculator (100) for calculating the frequency for each point on the object from a one dimensional intensity signal associated with that point.

Abstract: A digitized image of an object may include representations of portions of the object that are obscured, occluded or otherwise unobservable. The image may be a multi-dimensional visual representation of dentition. Characteristics of the dentition and its surfaces, contours, and shape may be determined and/or analyzed. A light may be directed toward and reflected from the dentition. The reflected light may be combined with a reference to determine characteristics of the dentition, including obscured areas such as subgingival tissue.

Abstract: Correction factors for the ALR and PTR parameters of magnetic-head sliders are determined by calculating an effective reflectivity and a corresponding PCOR at each pixel of the air-bearing surface. The absolute value of reflectivity at each pixel of the AlTiC air-bearing surface is obtained from an empirical equation relating it to modulation. The ratio of Al2O3 and TiC in the AlTiC surface is then calculated at every pixel assuming a linear relationship between the absolute value of AlTiC reflectivity and the theoretical reflectivity of each constituent. The linear relationship is then also used to calculate the effective (complex) reflectivity for the AlTiC material from the relative concentrations of Al2O3 and TiC at each pixel.

Abstract: A method and systems for reticle inspection. The method includes coherently illuminating surfaces of an inspection reticle and a reference reticle, applying a Fourier transform to scattered light from the illuminated surfaces, shifting the phase of the transformed light from the reference reticle such that a phase difference between the transformed light from the inspection reticle and the transformed light from the reference reticle is 180 degrees, combining the transformed light as an image subtraction, applying an inverse Fourier transform to the combined light, and detecting the combined light at a detector. An optical path length difference between two optical paths from the illumination source to the detector is less than a coherence length of the illumination source. The image detected by the detector represents a difference in amplitude and phase distributions of the reticles allowing foreign particles, defects, or the like, to be easily distinguished.