Abstract: A light source capable of spectral modulation is modulated conventionally to produce a correlogram at the test surface position of an SCI interferometer. The mean wavelength of the light source is changed to obtain multiple corresponding phase-shifted correlograms that can be processed by applying conventional multiple-wavelength interferometric analysis to determine physical attributes of the test surface. One simple way to achieve this result is by splitting the light beam produced by the source into at least three simultaneous beams passed through filters with corresponding different mean-wavelength transmission bands. Because the correlograms are produced simultaneously, they can be used to practice instantaneous phase-shifting interferometry using conventional analysis algorithms.

Abstract: The ROC value of a test surface is measured with a single spectrally-controlled interferometric measurement using a reference source of known ROC. The test surface is placed at the confocal position of the reference surface and the light source is modulated so as to produce localized interference fringes at the location of the test surface. The interference fringes are then processed with conventional interferometric analysis tools to establish the exact position of the test surface in relation to the reference surface, thereby determining the distance between the test surface and the reference surface. The radius of curvature of the test surface is obtained simply by subtracting such distance from the known radius of curvature of the reference surface.

Abstract: Interference fringes in a bullseye pattern are produced by a measurement module by interfering a flat reference beam with a spherical beam reflected by a sphere connected to the tip of a probe in point contact with a test object. The bullseye interferogram is registered at a detector and analyzed conventionally to produce a position measurement of the tip of the probe. A beam correction module is used to align the bullseye interferogram with the illumination axis of the measurement module. By combining at least three such measurement modules in a coordinate measurement machine, the three-dimensional position of the probe and of its point contact with the test object can be obtained from analysis of the bullseye interferograms registered by the detectors with high precision and greatly reduced Abbe error.

Abstract: In order to align the various components of an instrument, the beam produced by a spectrally-controlled light source is aligned with the optical axis of the instrument and the first component is placed at its predetermined position along the optical axis. Then, configuring the spectral modulation of the source such that one surface of the component is used as the reference surface, the spectrum of the source is modulated so as to produce a correlogram formed by reflections from the reference surface and from the other surface of the optical component. The correct alignment of the component is determined by adjusting its position so as to cause the correlogram to conform to the bullseye configuration that meets predetermined design parameters. The procedure is repeated with each other component of the instrument, the alignment of each component being based on interference fringes created independently of other components.

Abstract: Interference fringes in a bullseye pattern are produced by a measurement module by interfering a flat reference beam with a spherical beam reflected by a sphere connected to the tip of a probe in point contact with a test object. The bullseye interferogram is registered at a detector and analyzed conventionally to produce a position measurement of the tip of the probe. A beam correction module is used to align the bullseye interferogram with the illumination axis of the measurement module. By combining at least three such measurement modules in a coordinate measurement machine, the three-dimensional position of the probe and of its point contact with the test object can be obtained from analysis of the bullseye interferograms registered by the detectors with high precision and greatly reduced Abbe error.

Abstract: The ROC value of a test surface is measured with a single spectrally-controlled interferometric measurement using a reference source of known ROC. The test surface is placed at the confocal position of the reference surface and the light source is modulated so as to produce localized interference fringes at the location of the test surface. The interference fringes are then processed with conventional interferometric analysis tools to establish the exact position of the test surface in relation to the reference surface, thereby determining the distance between the test surface and the reference surface. The radius of curvature of the test surface is obtained simply by subtracting such distance from the known radius of curvature of the reference surface.

Abstract: Heterodyne spectrally controlled interferometry is performed by combining a delay line in Twyman-Green configuration with a Fizeau interferometer. By splitting a white-light beam in the delay line and introducing a time delay in one of the resulting beams, the delay line produces a recombined output beam with a sinusoidally modulated spectrum. By introducing a frequency shift in one of the beams in the delay line, the output beam is also continuously phase shifted in the spectral domain in a time-varying fashion, as required for heterodyne SCI.

Abstract: A tunable light source having a temporal coherence length such that interference fringes are detected within the optical path difference of the interferometer is spectrally controlled to produce multiple wavelengths during sequential fractions of the integration time of the detector of the interferometer. The wavelengths are selected so as to produce a visible correlogram at each integration time according to spectrally controlled interferometry (SCI) principles. Such different wavelengths may be produced by stepwise or continuous modulation. The modulation step is repeated sequentially while changing the period of modulation to produce a succession of predetermined spatial patterns of interference fringes, as required for interferometric measurements. The approach enables the practice of SCI with common-path apparatus used for conventional phase shifting, thereby combining the advantages of high-coherence and white-light interferometry.

Abstract: Heterodyne interferometry is combined with spectrally-controlled interferometry (SCI) to achieve the advantages of both. Phase shifts produced by SCI produce phase-shifted correlograms suitable for heterodyne interferometric analysis, thereby enabling interferometric measurements with conventional common-path apparatus free of coherence noise and scanning-related errors, and with the precision of conventional heterodyne interferometry. A spectrum-modulating light source suitable for the invention is obtained by combining a rotating spiral grating with a multi-slit grating placed in the front focal plane of a collimating lens that propagates the light toward a blazed diffraction grating. Another exemplary spectrum-modulating light source is obtained by combining a slit spectrometer with an acousto-optic modulator.

Abstract: A tunable light source having a temporal coherence length such that interference fringes are detected within the optical path difference of the interferometer is spectrally controlled to produce multiple wavelengths during sequential fractions of the integration time of the detector of the interferometer. The wavelengths are selected so as to produce a visible correlogram at each integration time according to spectrally controlled interferometry (SCI) principles. Such different wavelengths may be produced by stepwise or continuous modulation. The modulation step is repeated sequentially while changing the period of modulation to produce a succession of predetermined spatial patterns of interference fringes, as required for interferometric measurements. The approach enables the practice of SCI with common-path apparatus used for conventional phase shifting, thereby combining the advantages of high-coherence and white-light interferometry.

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: Heterodyne interferometry is combined with spectrally-controlled interferometry (SCI) to achieve the advantages of both. Phase shifts produced by SCI produce phase-shifted correlograms suitable for heterodyne interferometric analysis, thereby enabling interferometric measurements with conventional common-path apparatus free of coherence noise and scanning-related errors, and with the precision of conventional heterodyne interferometry. A spectrum-modulating light source suitable for the invention is obtained by combining a rotating spiral grating with a multi-slit grating placed in the front focal plane of a collimating lens that propagates the light toward a blazed diffraction grating. Another exemplary spectrum-modulating light source is obtained by combining a slit spectrometer with an acousto-optic modulator.

Abstract: A tunable light source having a temporal coherence length such that interference fringes are detected within the optical path difference of the interferometer is spectrally controlled to produce multiple wavelengths during sequential fractions of the integration time of the detector of the interferometer. The wavelengths are selected so as to produce a visible correlogram at each integration time according to spectrally controlled interferometry (SCI) principles. Such different wavelengths may be produced by stepwise or continuous modulation. The modulation step is repeated sequentially while changing the period of modulation to produce a succession of predetermined spatial patterns of interference fringes, as required for interferometric measurements. The approach enables the practice of SCI with common-path apparatus used for conventional phase shifting, thereby combining the advantages of high-coherence and white-light interferometry.

Abstract: A tunable light source having a temporal coherence length such that interference fringes are detected within the optical path difference of the interferometer is spectrally controlled to produce multiple wavelengths during sequential fractions of the integration time of the detector of the interferometer. The wavelengths are selected so as to produce a visible correlogram at each integration time according to spectrally controlled interferometry (SCI) principles. Such different wavelengths may be produced by stepwise or continuous modulation. The modulation step is repeated sequentially while changing the period of modulation to produce a succession of predetermined spatial patterns of interference fringes, as required for interferometric measurements. The approach enables the practice of SCI with common-path apparatus used for conventional phase shifting, thereby combining the advantages of high-coherence and white-light interferometry.

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 spectrally controlled light source includes a light source with a spectral distribution repeated with a predetermined spatial period along an input plane so as to produce multiple copies of the spectral distribution separated by the spatial period. All copies are propagated through dispersive optics to produce equally dispersed spectra on an image plane. A periodic modulating element with a given filter period is applied to each of the dispersed spectra to produce corresponding modulated outputs. According to the invention, the spatial period of the light source on the image plane and the filter period of the modulating element are selected so as to produce a resonance effect that greatly enhances the utility of the spectrally modulated source.

Abstract: An imaging apparatus consists of multiple miniaturized microscopes arranged into an array capable of simultaneously imaging respective portions of an object. A continuous linear translation approach is followed to scan the object and generate multiple image swaths of the object. In order to improve the quality of the composite image produced by concatenation of the image swaths, the performance of each microscope is normalized to the same base reference for each relevant optical-system property. Correction factors are developed through calibration to equalize the spectral response measured at each detector, to similarly balance the gains and offsets of the detector/light-source combinations associated with the various objectives, to correct for geometric misalignments between microscopes, and to correct optical and chromatic aberrations in each objective.

Abstract: A method for referencing image data. Preferred methods include methods for linking, characterizing, searching, and navigating the image data, as aids to reviewing the image data.

Abstract: In a scanning microscope, slides are fed automatically from a magazine to the imaging system. Each slide is labeled in some fashion with information for selecting the appropriate modality of operation of the scanner for that slide and the modality is implemented automatically. The information is preferably tied to and defined by a laboratory information system (LIS). For example, the instructions may regard the type of microscopy (i.e., trans- or epi-illumination), multi-spectral imaging with particular spectral bands combined with a particular set of z-positions, alternative filters, settings for the numerical aperture of the condenser, alternative detector operation for different resolutions, and alternative post-scan analyses of the data, as deemed optimal for the scan. The label may also contain the slide's identity, a pathologist's name, desired post-scan handling protocol, etc. The preferred array microscope to carry out the invention is also described.

Abstract: An array microscope scans a slide in rapid sequence at different wavelengths to record multiple spectral images of the sample. Full spatial resolution of the image sensor is realized at each color because pixels are not shared between spectral bands. The object and detector are placed at conjugate distances selected to produce substantially equal magnification with minimum chromatic aberration at all wavelengths to ensure registration of all images. Spectral analysis is carried out by combining the images captured at each wavelength. The greater-than-RGB spectral resolution provided by the combination of images enables the isolation and display of the effects produced by the contemporaneous use of more than two stains on a tissue for improved pathological analysis.