Abstract: The present invention provides a band-pass filter, being capable of fitting a frequency spectrum area having phase information in a frequency spectrum image, to obtain a spectrum information corresponding to the phase information during the process of obtaining the phase information from the frequency spectrum image with respect to an object's surface profile. In another embodiment, the present invention further provides a method to optimize the spectrum range of the band-pass filter so as to enhance measuring accuracy and efficiency while restoring the surface of the object. In addition, by employing the foregoing method, the present invention further provides a measurement system for measuring three-dimensional surface shapes in which a deformed fringe pattern with respect to the measured object's surface is acquired and the phase information is obtained from the fringe pattern according to the foregoing method so as to restore the surface profile of the measured object.

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: 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: A method for combining shape data from multiple views in a common co-ordinate system to define the 3-D shape and/or colour of an object, the method comprising: projecting one or more optical datum(s)/markers onto the object surface; projecting light over an area of the object surface; capturing light reflected from the surface; using the optical datum(s)/markers as reference points in multiple views of the object, and using the multiple views and the reference points to determine the shape of the object.

Abstract: Described is a multiple channel interferometric surface contour measurement system. The measurement system includes a multiple channel interferometer projector, a digital camera and a processor. The projector includes two or more interferometer channels. Each channel has an optical axis spatially separate from the optical axes of the other channels. Each channel projects a fringe pattern onto the surface of an object to be measured. Image data for the fringe patterns projected on the object surface are acquired by the digital camera. The processor controls the projection of the fringe patterns of different spatial frequencies, adjusts the phase of each fringe pattern and generates surface contour data in response to the camera image data. The multiple channel interferometric surface contour measurement system provides numerous advantages over conventional single channel interferometric systems, including reduced sensitivity to optical noise, improved stability and increased measurement accuracy.

Abstract: A coherence scanning interferometer (2) carries out: a coherence scanning measurement operation on a surface area (81) carrying a structure using a low numeric aperture objective so that the pitch of the surface structure elements (82) is much less that the spread of the point spread function at the surface (7) to obtain structure surface intensity data; and a coherence scanning measurement operation on a non-structure surface area (83), which may be part of the same sample or a different sample, to obtain non-structure surface intensity data. A frequency transform ratio determiner (105) determines a frequency transform ratio (the HCF function) related to the ratio between the structure surface intensity data and the non-structure surface intensity data.

Abstract: The invention relates to a method of reconstructing a surface topology of a surface (1) of an object (2). Conventional methods such as interferometry, or methods which acquire measurement values which represent slopes of the surface profile (slope values), show only a limited height resolution in the case of large flat objects such as wafers. In order to overcome this problem the surface of the object is sub-divided into smaller areas, and from each area slope values are obtained at optimum apparatus parameters. Then the areas are stitched together and the 3D topography is reconstructed.

Abstract: An optical object measurement apparatus includes a light source for generating a low-coherent light beam, which is swept via an array of pinholes on a Nipkow disk that rotates about an axis. A beam splitter splits the swept light beam into a probe light beam toward an object to be measured and a reference light beam toward a reference optical path. The probe light beam from the object and the reference light that has traveled along the reference optical path are combined in the beam splitter to produce interference light. A two-dimensional image-capturing device detects the interference light and produces a video signal to provide reflection intensity information of the interior of the object. This allows an interference optical system to be readily realized and tomographic images of an object to be observed at high levels of resolution and contrast.

Abstract: The invention refers to an apparatus for mapping a surface profile of a surface of an object, by which the apparatus yields slope data. The slope data of the apparatus may comprise measurement errors, which according to the invention shall be detected and corrected for. It is suggested that a computational entity calculates for all measurement values the curl of the slope data for determining surface locations at which the measurement values exhibit measurement errors. In a second step the proposal is given with which the measurement values can be corrected.

Abstract: A method of manufacturing an optical element involves an interferometric test of the optical element using an interferometer system of a Fizeau type combined with principles of white-light interferometry. The optical element is disposed in a cavity between a Fizeau surface and a mirror, and an optical path difference between a back surface of the optical element and the mirror is determined for determining parameters of the optical element, such as a thickness thereof. Measuring light from an optical delay apparatus can be supplied to the Fizeau interferometer through an optical fiber.

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: A device and method for detecting the presence or absence of an object which has repetitive motion are disclosed comprising, a receiver for receiving a signal from the object, and circuitry for determining the presence or absence of the object to be detected, wherein the circuitry records the signal from the receiver as a pattern of data during at least part of the repetitive motion of the object, compares the data with a previously recorded data pattern and, produces an output signal based on the comparison. The signal may be received during discrete time intervals, and may be light which can be transmitted with varying intensity. The circuitry may determine the value of signal received at a receiver and produce a binary value. The signal received at the receiver can be reflected from the object to be detected.

Abstract: A method of manufacturing an optical element includes testing the optical element by using an interferometer optics generating a beam of measuring light illuminating only a sub-aperture of the tested optical element. The interferometer optics comprises a hologram. Results of the sub-aperture measurement are stitched together to obtain a measuring result with respect to the full surface of the optical element. Further, a method of calibrating the interferometer optics includes performing an interferometric measurement using a calibrating optics having a hologram covering only a sub-aperture of the full cross section of the beam of measuring light generated by the interferometer optics and stitching together the sub-aperture measurements to obtain a result indicative for the full cross section of the interferometer optics.

Abstract: In certain aspects, interferometry methods are disclosed that include providing one or more interferometry signals for a test object, wherein the interferometry signals correspond to a sequence of optical path difference (OPD) values which are not all equally spaced from one another because of noise, providing information about the unequal spacing of the sequence of OPD values, decomposing each of the interferometry signals into a contribution from a plurality of basis functions each corresponding to a different frequency and sampled at the unequally spaced OPD values, and using information about the contribution from each of the multiple basis functions to each of the interferometry signals to determine information about the test object.

Abstract: A stroboscopic imaging interferometer system includes an environmental chamber having a novel viewing window equipped with a rigidly integrated beam splitter and piezo actuated reference mirror for illuminating a device providing an object beam and reference mirror for providing a reference beam, upon the reflection of both beams, produces interference of the object beam by the reference beam for providing absolute phase observations of the device, that may be a MEMS device under test.

Abstract: A phase-shifting interferometry (PSI) method and corresponding system including: (i) recording an interferogram for each phase in a sequence of phases between test light reflected from a test surface and reference light reflected from a reference surface, the test and reference light being derived from a common source, each interferogram corresponding to an intensity pattern produced by interfering the reflected test light with the reflected reference light, the interferograms defining an interferometry signal for each of different transverse locations of a cavity defined by the test and reference surfaces, each interferometry signal including a series of intensity values corresponding to the sequence of phases, with the difference between each pair of phases in the sequence defining a corresponding phase shift increment; (ii) calculating an initial phase map for the cavity based on at least some of the recorded interferograms; (iii) calculating an estimate for each of at least some of the phase shift increme

Abstract: In general, in one aspect, the invention features a method including providing scanning interferometry data for a test object using phase shifting interferometry, the data including intensity values for each of multiple scan positions for different spatial locations of the test object, the intensity values for each spatial location defining an interference signal for the spatial location, the intensity values for a common scan position defining a data set for that scan position. The method also includes temporally transforming at least some of the interference signals into a first frequency domain signal, determining an estimated phase profile of the test object based on the first frequency domain signal, determining phase shifts at multiple scan positions based on the estimated phase profile, and determining a more accurate phase profile of the test object based on the estimated phase profile and the phase shifts.

Abstract: A method of measuring topology of functional liquid in a pixel, in which thickness or volume of the functional liquid in the pixel is measured by a surface topology measuring apparatus comprising: measuring surface topologies in which surface topology of the functional liquid in the pixel and surface topology of the bank are measured by the surface topology measuring apparatus, and measurement parameters regarding the surface topologies are generated; adding a bank height in which a height parameter of a height of the bank is added to the measurement parameter of a surface of the functional liquid in the pixel of the measurement parameter generated; and calculating topology in which the thickness or the volume of the functional liquid in the pixel is calculated based on the added measurement parameter of the surface of the functional liquid in the pixel and the measurement parameter of the surface of the bank.

Abstract: The relative position of a test surface is sequentially changed from a reference position where a surface central axis is aligned with a measurement optical axis such that the measurement optical axis is sequentially moved to a plurality of annular regions obtained by dividing the test surface in a diametric direction. The test surface is rotated on a rotation axis whenever the relative position is changed. Measurement light that travels while being converged by a Mirau objective interference optical system is radiated to the rotating test surface, and a one-dimensional image sensor captures interference fringes at each of a plurality of rotational positions. The shape information of each annular region is calculated on the basis of the captured interference fringes at each rotational position, and the shape information is connected to calculate the shape information of the entire measurement region.

Abstract: Three-dimensional shape measuring instrument (white interferometer) for measuring the three-dimensional shape of an object to be measured by using white interference fringes, which detects the position where the amplitude of the white interference fringes takes on a maximum value with high accuracy in a short calculation processing time. An envelope distribution of the amplitude of the white interference fringes produced by the interference between the returning light from a reference mirror (6) and the returning light from an object (7) to be measured is determined, and an approximate position where the contrast of the white interference fringes is the highest is determined using this envelope distribution.

Abstract: The system and the method of the present invention differ from the prior art in that radii of curvature of any length of spherical and cylindrical test surfaces can be optically measured, with only a supplementary dual-focus lens being required in addition to an interferometer or an autocollimator. The supplementary dual-focus lens has a first focal plane, into which the surface vertex of the test surface is positioned, which establishes the cat's eye position (P(cat)), and a second focal plane into which the center of curvature of the test surface is moved, which establishes the autocollimation position (P(aut)) for the test surface. The radius of curvature of the test surface is determined from the distance between the focal planes (D(foc)) and the path of movement which can be reduced to zero.

Abstract: The relative position of a test surface is sequentially changed from a reference position where a surface central axis is aligned with a measurement optical axis such that the measurement optical axis is sequentially moved to a plurality of annular regions obtained by dividing the test surface in a diametric direction. The test surface is rotated on a rotation axis whenever the relative position is changed. Measurement light composed of a plane wave is radiated to the rotating test surface, and a one-dimensional image sensor captures interference fringes at each of a plurality of rotational positions. The shape information of each annular region is calculated on the basis of the captured interference fringes at each rotational position, and the shape information is connected to calculate the shape information of the entire measurement region.

Abstract: A fiber optic sensor head for detecting the shape or the distance of a test object has an optical fiber, in particular a glass fiber, for conducting and returning partial beams to and from the test object, and an injection/extraction lens on the test object side. For conducting partial beams, injected on the sensor head side and having an optical path length difference, to the test object and returning partial beams injected on the test object side without an optical path length difference, a Fizeau interferometer having a nondiscrete design is associated with the optical fiber and compensates for the optical path length difference between the partial beams.

Abstract: Disclosed is an interferometry analysis method that includes comparing information derivable from multiple interferometry signals corresponding to different surface locations of a test object to information corresponding to multiple models of the test object, wherein the multiple models are parameterized by a series of characteristics that relate to one or more under-resolved lateral features of the test object; and outputting information about the under-resolved surface feature based on the comparison.

Abstract: Apparatus for imaging a surface, including scanning optics, which are configured to scan and focus one or more traveling beams onto the surface so as to form one or more traveling spots thereon. The apparatus also includes collection optics, which are arranged to collect radiation scattered from the one or more traveling spots and to focus the radiation to form one or more image spots traveling along a line. The apparatus also has a detecting assembly, which consists of a detector which is configured to generate a signal in response to the one or more traveling image spots, and a detector entry port interposed between the collection optics and the detector, which is coincident with the line. The apparatus also includes phase and/or polarization altering elements for the traveling beams.

Abstract: An intra-oral laser digitizer system provides a three-dimensional visual image of a real-world object such as a dental item through a laser digitization. The laser digitizer captures an image of the object by scanning multiple portions of the object in an exposure period. The intra-oral digitizer may be inserted into an oral cavity (in vivo) to capture an image of a dental item such as a tooth, multiple teeth or dentition. The captured image is processed to generate the three-dimension visual image.

Abstract: An acoustic field in a body of water is monitored using a coherent light field emitter applying a distributed light field across the surface of the water to be reflected, and a sensor is used to sense reflected components of the light field above the surface and to provide a signal representing information in the reflected light and related to movements in the water and caused by the acoustic field. The signal is provided from an interferometry technique and useable to derive information on the underwater acoustic field in a useful form.

Abstract: A method for determining a spatial property of an object includes obtaining a scanning low coherence interference signal from a measurement object that includes two or more interfaces. The scanning low coherence interference signal includes two or more overlapping low coherence interference signals, each of which results from a respective interface. Based on the low coherence interference signal, a spatial property of at least one of the interfaces is determined. In some cases, the determination is based on a subset of the low coherence interference signal rather than on the entirety of the signal. Alternatively, or in addition, the determination can be based on a template, which may be indicative of an instrument response of the interferometer used to obtain the low coherence interference signal.

Abstract: A scatterometer-interferometer and method for detecting and distinguishing characteristics of surface artifacts provides improved artifact detection and increased scanning speed in interferometric measurement systems. A scatterometer and interferometer are combined in a single measurement head and may have overlapping, concentric or separate measurement spots. Interferometric sampling of a surface under measurement may be initiated in response to detection of a surface artifact by the scatterometer, so that continuous scanning of the surface under measurement can be performed until further information about the size and/or height of the artifact is needed.

Abstract: In one embodiment, an interferometer system comprises an unequal path interferometer assemble comprising; a first reference flat having a first length L1 in a first dimension, a second reference flat having a second length L2 in the first dimension, a cavity D1 defined by a distance between the first reference flat and the second reference flat, and a receptacle to receive an object in the cavity such that an optical path remains open between the first reference flat and the second reference flat, and a radiation targeting assembly to direct a collimated radiation beam to the interferometer assembly, a radiation collecting assembly to collect radiation received from the interferometer assembly, and a controller comprising logic to; vary a wavelength of the collimated radiation beam, record interferograms formed by a plurality of surfaces, extract phases of each of the interferograms for each of the plurality of surfaces to produce multiple phase maps, and determine each phase map from its corresponding interf

Abstract: A fundus oculi observation device 1 divides a low-coherence light L0 into a signal light LS and a reference light LR, superimposes the signal light LS propagated through a a fundus oculi Ef and the reference light LR propagated through a reference mirror 174 to generate and detect an interference light LC, and forms an OCT image of the fundus oculi Ef based on the result of the detection. The fundus oculi observation device 1 scans with the signal light LS while changing a scan interval when performing a series of scans with the signal light LS. Thus, it is possible to acquire a highly accurate image at small scan intervals from an attention site, and it is possible to reduce a scanning time by scanning at large intervals in other sites. Accordingly, it is possible to rapidly acquire a highly accurate image of an attention site.

Abstract: A vibration-resistant interferometric scanning system and method are provided in the present invention. In the present invention, the brightness distribution in a high-coherence interference pattern is analyzed so as to perform a compensation action to lock the brightness distribution of a high-coherence interference pattern and consequently locking the fringe distribution of a low-coherence interference pattern or to perform a scanning operation composed of plural shifting actions with specified scanning distances in sequence and plural compensation actions to lock the fringe distribution in a low-coherence interference pattern corresponding to the surface profile of a measured object. Consequently, with the system and method of the present invention, the surface profile of a measured object disturbed by external or internal vibrations can be measured accurately and precisely.

Abstract: A calibrating jig comprises a reference sphere, and a reflecting plate configured to support the reference sphere from a lower side thereof and mirror-reflect light in a case that the reference sphere is illuminated from an upper side thereof.

Abstract: A test object including: an arrangement of optical elements defining a first partially reflecting surface and a second partially reflecting surface, at least one of the first and second partially reflecting surfaces being curved, wherein the first partially reflecting surface is arranged to receive a substantially collimated input beam and produce therefrom a first transmitted beam that passes on to the second partially reflecting surface, wherein the second partially reflecting surface is arranged to receive the first transmitted beam from the first partially reflecting surface and produce a collimated second transmitted beam and a first reflected beam therefrom, wherein the first partially reflecting surface is arranged to receive the first reflected beam and produce a second reflected beam therefrom, and wherein the first and second reflecting surfaces are configured to cause the second reflecting beam to converge onto a spot on a back surface to produce a diverging beam traveling in the same direction as

Abstract: An optical coherence tomographic imaging apparatus which has a light intensity varying portion provided on a first optical path for guiding a measuring beam to an object for varying an intensity of the measuring beam; an illumination condition varying portion for varying an illumination condition of the measuring beam that has passed through the light intensity varying portion for the object between a first illumination condition in which a center part of the measuring beam is not blocked and a second illumination condition in which the center part of the measuring beam is blocked; and an image forming portion for weighting a first tomographic image acquired in the first illumination condition and a second tomographic image acquired in the second illumination condition and composing the weighted first second tomographic images to form a third tomographic image.

Abstract: Methods and apparatus to perform wavefront analysis, including phase and amplitude information, and 3D measurements in optical systems, and in particular those based on analyzing the output of an intermediate plane, such as an image plane, of an optical system. Measurement of surface topography in the presence of thin film coatings, or of the individual layers of a multilayered structure is described. Multi-wavelength analysis in combination with phase and amplitude mapping is utilized. Methods of improving phase and surface topography measurements by wavefront propagation and refocusing, using virtual wavefront propagation based on solutions of Maxwell's equations are described. Reduction of coherence noise in optical imaging systems is achieved by such phase manipulation methods, or by methods utilizing a combination of wideband and coherent sources.

Abstract: In an optical tomographic imaging apparatus, a wavelength of a light beam emitted from the light source is selected by a light source section filter, and the light beam emitted from the light source is split into a measurement light beam and a reference light beam. The measurement light beam is reflected from a measurement subject when the measurement light beam is irradiated, is amplified. A specific wavelength from the amplified reflected light beam is selected by an amplifying section filtering mechanism having a filter characteristic identical to a time variation characteristic of the light source section filter, and then the reflected light beam is multiplexed with the reference light beam. A tomographic image of the measurement subject is acquired from detection result of an interference light beam between the reflected light beam and the reference light beam which have been multiplexed.

Abstract: The device comprises a light source (LED), beam splitters, illumination pattern generating mechanism and interchangeable microscope lenses that are lenses that may be used to obtain confocal images and lenses that may be used to obtain interferometric images. The generating mechanism can generate a sequence of illumination patterns to obtain confocal images, or total opening of all the illumination pixels to obtain interferometric images.

Abstract: Light emitted from the light source unit is divided into measuring light and reference light. An optical path length of the measuring light or the reference light which has been divided by the light dividing means is adjusted. Interference light of the reflected light and the reference light is detected and a tomographic image of the object is obtained on the basis of the detected interference light. The optical path length is adjusted by a reflecting mirror which reflects the measuring light or the reference light radiated from the optical fiber, a first lens which is disposed between the reflecting mirror and the optical fiber and a second lens which collects the measuring light or the reference light made parallel by the first lens on the reflecting mirror and makes parallel the measuring light or the reference light reflected by the reflecting mirror.

Abstract: The invention is directed to a method for controlling a critical dimension of a patterned photoresist layer. The method comprises steps of measuring a critical dimension of a raised pattern in a patterned photoresist layer after a photolithography process is performed on the photoresist layer. A determining process is performed to determine whether the critical dimension is within a critical dimension control limit range, wherein the critical dimension control limit range has a upper control limit and a lower control limit. An adjusting process is performed when the critical dimension is not within the critical dimension control limit range. When the critical dimension is smaller than the lower control limit, a photoresist reflow process is performed. When the critical dimension is larger than the upper control limit a photoresist trimming process is performed.

Abstract: A microscope which has a high three-dimensional resolution, does not require specimens to be stained and is easy to operate, is presented. The three-dimensional microscope includes a first optical system for illuminating an object with lights in a plurality of illuminating directions, one direction after another; an imaging section; a second optical system for guiding diffracted lights generated by the object and reference lights to the imaging section that obtains interference images of the diffracted lights and the reference lights; and a processor for generating a three-dimensional image using the interference images for respective illuminating directions, obtained by the imaging section. The processor obtains complex amplitudes of the diffracted lights from the interference images for respective illuminating directions and generates the three-dimensional image of the object from the complex amplitudes.

Abstract: A method is disclosed which includes: using a scanning interferometry system, generating a sequence of phase-shifted interferometry images at different scan positions of an object comprising a buried surface, identifying a scan position corresponding to a position of best focus for the buried surface based on the sequence of phase-shifted interferometry images of the object, and generating a final image based on the phase-shifted interferometry images and the scan position, where the interferometric fringes in the final image are reduced relative to the interferometric fringes in the phase-shifted interferometry images.

Abstract: A surface shape measurement apparatus is configured to measure a surface shape of an object to be measured, and includes a beam splitter configured to split white light from a light source into two light beams, a pair of prisms each configured to increase an incident angle of each light beam that has been split by the beam splitter and directed to the object or a reference surface, each prism having an antireflection part that is formed at a period of a wavelength of the white light or smaller and has a moth-eye shape, a superimposition unit configured to superimpose object light from the object with reference light from the reference surface and has passed the second prism, and to generate white interference light, and a Lyot filter configured to discretely separate the white interference light for each of a plurality of wavelengths.

Abstract: A method is disclosed which includes, for each of multiple areas of a test surface on a test object having different reflectivities, using an interferometry system to measure each area in a first mode of operation that measures information about the reflectivity of the area over a range of angles and wavelengths; using the same interferometry-system to measure the test surface in a second mode of operation that interferometrically profiles a topography of the test surface over a range including at least some of the multiple areas; and correcting the profile based on the information about the reflectivity of the multiple areas to reduce errors.

Abstract: Disclosed is a system including: (i) an interferometer configured to direct test electromagnetic radiation to a test surface and reference electromagnetic radiation to a reference surface and subsequently combine the electromagnetic radiation to form an interference pattern, the electromagnetic radiation being derived from a common source; (ii) a multi-element detector; and (iii) one or more optics configured to image the interference pattern onto the detector so that different elements of the detector correspond to different illumination angles of the test surface by the test electromagnetic radiation.

Abstract: To provide a method for measuring a plane mirror or a curved surface mirror close to plane mirror for condensing hard X-rays or soft X-rays used in a radiation light facility, especially an elliptical or tubular object having a steep profile exceeding 1×10?4 rad, ultra precisely with a precision on nano order or sub-nano order. Overall profile is measured by using overall profile data obtained from a Fizeau interferometer and stitching a plurality of micromeasurement data from a Michelson microinterferometer.

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: A new and useful imaging concept is provided that is designed to improve the manner in which control information for an imaging optical system such as a lithographic imaging optical system can be generated. An imaging optical system comprises imaging optics defining a primary optical path along which a primary image is imaged, and a measurement optical path is established and includes at least part of the primary optical path. The imaging optical system is configured to obtain information from the measurement optical path for use in providing control information for the imaging optical system. Such a system is particularly useful for measuring the topography of a large region of the surface under investigation, like the entire instantaneous field of a wafer, instead being limited to a small patch or set of patches.

Abstract: Disclosed herein is a moiré shape measurement apparatus using a Liquid Crystal Display (LCD) panel. The moiré shape measurement apparatus includes a light source, a variable grating, a viewing lens, a light receiving unit, a computation unit, and a driving device. The light source emits light. The variable grating passes the emitted light therethrough, and creates a projection grating pattern. The viewing lens focuses a reflected grating pattern that is obtained when the projection grating pattern is reflected from the object. The light receiving unit receives the light of the reflected grating pattern passed through the viewing lens. The computation unit previously stores the viewing grating pattern, forms the moiré pattern by overlaying the reflected grating pattern, received from the light receiving unit, on the stored viewing grating pattern, and computes the shape of the object using the moiré pattern. The driving device adjusts a direction and a pitch in order to form a grating of the variable grating.

Abstract: A structured light sensor system for measuring contour of a surface includes an imaging lens system, an image capturing device, a first set of micro electromechanical system (MEMS) mirrors, and a control module. The imaging lens system focuses light reflected from the surface, wherein the imaging lens system has a corresponding lens plane. The image capturing device captures the focused light and generates data corresponding to the captured light, wherein the image capturing device has a corresponding image plane that is not parallel to the lens plane. The first set of MEMS mirrors direct the focused light to the image capturing device. The control module receives the data, determines a quality of focus of the captured light based on the received data, and controls the first set of MEMS mirrors based on the quality of focus to maintain a Scheimpflug tilt condition between the lens plane and the image plane.