Abstract: Methods for characterizing the surface shapes of optical elements include the following steps: carrying out, in an interferometric test arrangement, at least a first interferogram measurement on the optical element by superimposing a test wave, which has been generated by diffraction of electromagnetic radiation on a diffractive element and has been reflected at the optical element, carrying out at least one additional interferogram measurement on in each case one calibrating mirror for determining calibration corrections, and determining the deviation from the target shape of the optical element based on the first interferogram measurement carried out on the optical element and the determined calibration corrections. At least two interferogram measurements are carried out for the at least one calibrating mirror, which differ from one another with regard to the polarization state of the electromagnetic radiation.

Abstract: An optical system including a first light source, a first lens, and a light splitting module, wherein the light splitting module has a first splitter, a second lens, a first camera and a second camera, the first lens is configured for receiving a first light beam from the first light source and collimating the first light beam onto a sample, and for receiving and collimating a light beam from the sample, the second lens is configured for focusing the collimated light beam from the first lens to the first camera and the second camera, the first splitter is configured for splitting the focused light beam from the second lens into a second light beam and a third light beam, the first camera is configured for receiving the second light beam, and the second camera is configured for receiving the third light beam.

Abstract: A method, a system, and a non-transitory computer readable medium for Raman spectroscopy. The method may include determining first acquisition parameters of a Raman spectroscope to provide a first acquisition set-up, the determining is based on at least one expected radiation pattern to be detected by a sensor of the Raman spectroscope as a result of an illumination of a first area of a sample, the first area comprises a first nano-scale structure, wherein at least a part of the at least one expected radiation pattern is indicative of at least one property of interest of the first nano-scale structure of the sample; wherein the first acquisition parameters belong to a group of acquisition parameters; setting the Raman spectroscope according to the first acquisition set-up; and acquiring at least one first Raman spectrum of the first nano-scale structure of the sample, while being set according to the first acquisition set-up.

Abstract: An imaging apparatus includes a light source, a spatial light modulator, a Fourier transform optical system, a photodetector, and a control unit. The control unit sets a first region and a second region on a modulation plane of the spatial light modulator, sequentially sets a plurality of light phase modulation patterns in the first region, sequentially sets a plurality of uniform phase shifts in a region other than the first region when setting each light phase modulation pattern in the first region to acquire a light intensity value, and acquires a phase image of a region of an object corresponding to the first region using a phase shift method.

Abstract: A method for calibrating a measuring device (10) for interferometrically determining a shape of an optical surface (12) of an object under test (14). The measuring device includes a module plane (32) for arranging a diffractive optical test module (30) which is configured to generate a test wave (34) that is directed at the optical surface and that has a wavefront at least approximately adapted to a target shape (60) of the optical surface. The method includes: arranging a diffractive optical calibration module (44) in the module plane for generating a calibration wave (80), acquiring a calibration interferogram (88) generated using the calibration wave in a detector plane (43) of the measuring device, and determining a position assignment distribution (46) of points (52) in the module plane to corresponding points (54) in the detector plane from the acquired calibration interferogram.

Abstract: A method and apparatus for microscopic imaging is provided. The method includes: illuminating the sample with illumination radiation to stimulate the detection radiation; capturing the detection radiation from the sample; with the intensity data of the detection radiation from the sample; applying the calibration algorithm to the captured image(s) to acquire the processed second image; the resolution of the processed second image is higher than the acquired first image.

Abstract: A method, a system, and a non-transitory computer readable medium for accurate Raman spectroscopy. The method may include executing at least one iteration of the steps of: (i) performing, by an optical measurement system, a calibration process that comprises (a) finding a misalignment between a region of interest defined by a spatial filter, and an impinging beam of radiation that is emitted from an illuminated area of a sample, the impinging beam impinges on the spatial filter; and (b) determining a compensating path of propagation of the impinging beam that compensates the misalignment; and (ii) performing a measurement process, while the optical measurement system is configured to provide the compensating path of propagation of the impinging beam, to provide one or more Raman spectra.

Abstract: A protective device for a membrane of a sensor that detects a physical parameter acting upon the membrane includes a hollow main body that elongates in a direction along a longitudinal axis. The main body is open at one opposite end of the main body along the longitudinal axis, and at the end of the main body opposite the open end the protective device includes a bottom in which is defined a passage through which the medium is able reach the membrane when the protective device is attached to the sensor. The passage is defined in part by a wall that is configured so that the electromagnetic radiation propagating in the passage cannot reach the membrane without being reflected at least once on the wall.

Abstract: A method and system of nanoscale photoacoustic tomography (nPAT) for non-invasive three-dimensional mapping and characterization of fine cellular structures (such as but not limited to organelles, vesicles, and macromolecules) of biological samples is disclosed.

Abstract: A digital speckle pattern interferometer (DSPI) is provided for long-range measurement of displacement of materials within a hazardous environments. A test arm of a portion of coherent beam from a laser is aimed at a selected angle to traverse a distance to a test surface. An input collimator has a lens wide enough to receive a reflected beam from the test surface and is focused at a corresponding distance. The reflected beam is combined with a reference beam split from the coherent radiation onto a camera for measuring displacement of the test surface based on an electronic speckle pattern interferometer (ESPI).

Abstract: Embodiments of systems and methods for measuring a surface topography of a semiconductor chip are disclosed. In an example, a method for measuring a surface topography of a semiconductor chip is disclosed. A plurality of interference signals each corresponding to a respective one of a plurality of positions on a surface of the semiconductor chip are received by at least one processor. The interference signals are classified by the at least one processor into a plurality of categories using a model. Each of the categories corresponds to a region having a same material on the surface of the semiconductor chip. A surface height offset between a surface baseline and at least one of the categories is determined by the at least one processor based, at least in part, on a calibration signal associated with the region corresponding to the at least one of the categories.

Abstract: An optical inspection apparatus includes an interferometer module, which is configured to direct a beam of coherent light toward an area under inspection and to produce a first image of interference fringes of the area. The apparatus also includes a triangulation module configured to project a pattern of structured light onto the area, and at least one image sensor configured to capture the first image of interference fringes and a second image of the pattern that is reflected from the area. Beam combiner optics are configured to direct the beam of coherent light and the projected pattern to impinge on the same location on the area. A processor is configured to process the first and second images in order to generate a 3D map of the area.

Abstract: A film thickness measuring apparatus including: a measurement light path for irradiating a measurement target object with light from a light source; a correction light path for irradiating a reference member with light from the light source; and a light switching unit that selectively guides reflected light from the measurement target object or reflected light from the reference member, to a spectroscope.

Abstract: Embodiments of systems and methods for measuring a surface topography of a semiconductor chip are disclosed. In an example, a method for measuring a surface topography of a semiconductor chip is disclosed. A plurality of interference signals each corresponding to a respective one of a plurality of positions on a surface of the semiconductor chip are received by at least one processor. The plurality of interference signals are transformed by the at least one processor into a plurality of spectrum signals each corresponding to the respective one of the positions on the surface of the semiconductor chip. The spectrum signals are classified by the at least one processor into a plurality of categories using a model. Each of the categories corresponds to a region having a same material on the surface of the semiconductor chip.

Abstract: Methods of and apparatus for inspecting composite layers of a first material formed on a second material are provided including providing an illumination source, illuminating at least a portion of the composite at the layer, receiving light reflected from the sample, determining a spectral response from the received light, and comparing the received spectral response to an expected spectral response.

Abstract: A device and method for expediting spectral measurement in metrological activities during semiconductor device fabrication through interferometric spectroscopy of white light illumination during calibration, overlay, and recipe creation.

Abstract: A compensation optical unit (30) for a measurement system (10) for determining a shape of an optical surface (12) of a test object (14) by interferometry generates a measuring wave (44), directed at the test object, with a wavefront that is at least partly adapted to a target shape of the optical surface from an input wave (18). The unit includes first (32) and second (34) optical elements disposed in a beam path of the input wave. The second optical element is a diffractive optical element configured to split the input wave into the measuring wave and a reference wave (42) following an interaction with the first optical element. At least 20% of a refractive power of the entire compensation optical unit is allotted to the first optical element, and this allotted refractive power has the same sign as the refractive power of the entire compensation optical unit.

Abstract: A surface generation device includes: a profile curve setting unit 2 configured to set a profile curve fitted to a part of shape data, a profile curve movement unit 3 configured to move the profile curve so as to satisfy a predetermined condition, and a surface generation unit 4 configured to generate a surface defined by a locus obtained by moving the profile curve satisfying the predetermined conditions. The predetermined conditions include a condition in which a locus of one point (for example, midpoint) on the profile curve becomes a line of curvature of the surface to be generated. Using such a condition, it is possible to efficiently obtain the high quality surface by setting the line of curvature indicating a flow of the surface as a guide line of a sweep method without repeating trial and error many times.

Abstract: The wavefront measurement device performs: generating a first pupil function at a reference wavelength based on input data of a wavefront aberration; calculating a first image plane amplitude at a reference wavelength based on the first pupil function; generating a second pupil function at a multi-wavelength region; calculating a second image plane amplitude at the multi-wavelength region based on the second pupil function; correcting a measured point spread function using the first and second image plane amplitudes; applying a constraint condition using the corrected point spread function to the first image plane amplitude to correct the first image plane amplitude; generating a third pupil function based on the corrected first image plane amplitude; and calculating a wavefront aberration on a pupil plane based on the third pupil function.

Abstract: Disclosed are systems and methods to extract information about the size and shape of an object by observing variations of the radiation pattern caused by illuminating the object with coherent radiation sources and changing the wavelengths of the source. Sensing and image-reconstruction systems and methods are described for recovering the image of an object utilizing projected and transparent reference points and radiation sources such as tunable lasers. Sensing and image-reconstruction systems and methods are also described for rapid sensing of such radiation patterns. A computational system and method is also described for sensing and reconstructing the image from its autocorrelation. This computational approach uses the fact that the autocorrelation is the weighted sum of shifted copies of an image, where the shifts are obtained by sequentially placing each individual scattering cell of the object at the origin of the autocorrelation space.

Abstract: A method for adjusting a measuring device having an interferometer unit with an optical axis, an optical distance measuring device with a measuring axis and a support slide that is moveable along a slide axis. The measuring axis is first aligned parallel to the slide axis. An adjustment body with a first spherical reflection and/or diffraction surface and a retro reflector at the back side is arranged at the support slide. It is brought into a first confocal position, in which a first center point of the first spherical reflection/diffraction surface coincides with the focus of the spherical wavefront that is emitted from the interferometer unit. The retro reflector defines a vertex that is located close to the first center point, such that the measuring axis of the distance measuring device extends close to the focus of the emitted spherical wavefront. In doing so, Abbe-faults can be reduced or eliminated.

Abstract: Methods, devices and systems for up to three-dimensional scanning of target regions at high magnification are disclosed.

Abstract: A measurement system is presented for use in metrology measurements on patterned samples. The system comprises: at least one light source device configured to generate broadband light, at least one detection device configured to provide spectral information of detected light, and an optical system. The optical system comprises at least an oblique channel system for directing incident light generated by the light source(s) along an oblique illumination channel onto a measurement plane, on which a sample is to be located, and directing broadband light specularly reflected from the sample along a collection channel to the detection device(s). The optical system further comprises an interferometric unit comprising a beam splitting/combining device and a reference reflector device.

Abstract: An image capturing apparatus includes an image sensing device, a first acquisition unit, a second acquisition unit, and a display control unit. The first acquisition unit acquires an image acquired by using the image sensing device and three-dimensional information regarding a subject in the image. The three-dimensional information includes depth information regarding the image. The second acquisition unit acquires a shaping resolution indicating a resolution used by a shaping device to shape an object in a three-dimensional shape of the subject. The display control unit displays, based on the shaping resolution and the three-dimensional information regarding the subject, a relationship between a size of the subject and magnitude of the shaping resolution.

Abstract: A three-dimensional measurement device includes an optical system that: splits an incident light into two lights; radiates one light to a measurement object and the other light to a reference surface; and emits the combined light; a first irradiator that emits a first light that comprises a polarized light of a first wavelength and enters a first element of the optical system; a second irradiator that emits a second light that comprises a polarized light of a second wavelength and enters a second element of the optical system; a first camera that takes an image of the first light emitted from the second element when the first light enters the first element; a second camera that takes an image of the second light emitted from the first element when the second light enters the second element; and an image processor that performs measurement based on the images.

Abstract: Systems and methods are provided for performing phase-sensitive optical coherence tomographic (PS-OCT) measurements involving the vibrographic response of an acoustic stimulus. Detected signals are processed to provide sampled time-dependent vibrographic data characterizing a vibratory amplitude and phase response over one or more periods of the acoustic stimulus. The sampled time-dependent vibrographic data is processed to suppress the sinusoidal signal component associated with the acoustic stimulus, thereby providing a residual data associated with noise. The residual data is processed to obtain an estimate of the motion noise, and the motion noise is subtracted from the sampled time-dependent vibrographic data in order to provide noise-corrected vibrographic data. The noise-corrected vibrographic data can be processed to obtain one or more vibrographic measures and/or one or more images.

Abstract: A substrate having a plurality of features for use in measuring a parameter of a device manufacturing process and associated methods and apparatus. The measurement is by illumination of the features with measurement radiation from an optical apparatus and detecting a signal arising from interaction between the measurement radiation and the features. The plurality of features include first features distributed in a periodic fashion at a first pitch, and second features distributed in a periodic fashion at a second pitch, wherein the first pitch and second pitch are such that a combined pitch of the first and second features is constant irrespective of the presence of pitch walk in the plurality of features.

Abstract: A method for use in optical measurements on patterned structures, the method including performing a number of optical measurements on a structure with a measurement spot configured to provide detection of light reflected from an illuminating spot at least partially covering at least two different regions of the structure, the measurements including detecting light reflected from the at least part of the at least two different regions within the measurement spot, the detected light including interference of at least two complex electric fields reflected from the at least part of the at least two different regions, and being therefore indicative of a phase response of the structure, carrying information about properties of the structure.

Abstract: In a conventional moiré method, achieving both measurement accuracy and dynamic measurement and balancing field of view and measurement accuracy have been difficult. The present invention makes it possible to handle conventional moiré fringes as a grating for generating phase-shifted second-order moiré fringes, use a spatial phase shift method algorithm to accurately analyze the phases of the second-order moiré fringes before and after deformation, and determine shape from the phase differences between gratings projected onto the surface of an object of measurement and a reference surface and determine deformation and strain from the phase differences between the second-order moiré fringes, before and after deformation, of a repeating pattern on the object surface or a produced grating. As a result, it is possible to measure the three-dimensional shape and deformation distribution of an object accurately and with a wide field of view or dynamically and with a high degree of accuracy.

Abstract: An interferometer for areally measuring an optically smooth surface is presented, including means for illuminating a surface region with a plurality of discrete object waves from different directions and comprising means which, on a detector, superimpose object waves reflected at the surface onto a reference wave that is coherent with a plurality of object waves in order to form an interferogram. The interferometer is distinguished by virtue of it being configured to illuminate the surface with a plurality of object waves at the same time and produce the reference wave by way of a Fizeau beam splitter plate or a Fizeau objective, and by virtue of the interferometer including an interferometer stop that is arranged in the beam path upstream of the detector, and imaging optics, wherein the interferometer stop is situated within, or slightly outside of, the Fourier plane of the imaging optics and said interferometer stop filters the object waves reflected by the surface.

Abstract: According to an aspect of one or more embodiments, the present subject matter describes an apparatus for inspecting a slab of a material. The apparatus comprises a first and second low-coherence sensor configured to irradiate a first and second side of a slab of material with first light having a first polarization and second light having a second polarization, and thereafter configured to detect a reflection. A first polarizer is configured to allow reflected first light having the first polarization to pass through, and reject a second-light cross-talk portion having the second polarization. A second polarizer is configured to allow reflected second light having the second polarization to pass through, and reject a first-light cross-talk portion having the first polarization. Further, a computing-system is configured to receive signals representing the reflected first light and the reflected second light; and analyze the reflected first light and the reflected second light.

Abstract: The present disclosure provides an optical coherence tomography (OCT) system for characterising first and second areas of interest of a material. The OCT system comprises first and second optical elements in use positioned at the first and second areas of interest of the material. The first and second optical elements are at least partially transmissive for electromagnetic radiation. The system further comprises first and second scanning heads in use positioned at the first and second optical elements, respectively, to receive electromagnetic radiation that has interacted with the material at the first and second areas of interest. In addition, the system comprises at least one detector optically coupled to the first and second scanning heads.

Abstract: Exemplary embodiments of systems and methods can be provided which can generate data associated with at least one portion of a sample. For example, at least one first radiation can be forwarded to the portion through at least one optical arrangement. At least one second radiation can be received from the portion which is based on the first radiation. Based on an interaction between the optical arrangement and the first radiation and/or the second radiation, the optical arrangement can have a first transfer function. Further, it is possible to forward at least one third radiation to the portion through such optical arrangement (or through another optical arrangement), and receive at least one fourth radiation from the portion which is based on the third radiation. Based on an interaction between the optical arrangement (or the other optical arrangement) and the third radiation and/or the fourth radiation, the optical arrangement (or the other optical arrangement) can have a second transfer function.

Abstract: Provided herein are systems and methods for an active sensing instrument actively utilizing the Christiansen effect to sense and adapt to suspended scatterers such as dust. The instrument enhances detection of remote surfaces that are partially or fully obscured at visual wavelengths due to those suspended scatterers. The system also may be used to measure properties and spatial distributions of the suspended scatterers themselves. Though the system is broadly applicable to remote detection through scattering media, it is particularly drawn to remote sensing through dust particles in the atmosphere as may be produced from helicopter fly-overs, dust storms, or other events that draw up substantial concentrations of mineral-based dust particles into the air.

Abstract: Object: An object is to quantify the roughness of a test surface by scattering and diffraction of illumination light and to evaluate the matching degree of surface roughness separately from color based on a difference in roughness. Solution to Problem A surface roughness determination apparatus 1 using a white light source includes an arithmetic processing unit 3 configured to convert 3-band visual sensitivity images S1i, S2i and S3i, which respectively have three spectral sensitivities (S1(?), S2(?) and S3(?)) subjected to linear transformation so as to be equivalent to a CIE XYZ color matching function and are obtained from a surface 5 by a two-dimensional colorimeter 2 using the three spectral sensitivities (S1(?), S2(?) and S3(?)), into tristimulus values X, Y and Z in a CIE XYZ color system and perform arithmetic operations.

Abstract: An interference fringe projection apparatus includes light source units that selectively emit light from a coherent light source from one of a plurality of optical emitters, a polarization-maintaining waveguide unit with a plurality of PANDA fibers (polarization-maintaining waveguides) that each guide light emitted from one of the plurality of optical emitters, polarization splitters that split an optical path of light emitted from each of the PANDA fibers by polarization direction, and a polarizing film that transmits only a linear polarization component in a particular direction of light split by the polarization splitter. The light source unit only emits linearly polarized light in one polarization-maintaining direction for at least one of the PANDA fibers, and the polarization-maintaining waveguide unit causes retardation of light emitted from the PANDA fibers to vary.

Abstract: The laser processing device includes: a measuring device configured to measure a change in a height of an object and including a first light source configured to emit probe light, a first light focusing unit configured to focus the probe light on the object, a light sensing unit configured to detect a change in the probe light reflected from a reflective surface of the object and including a Shack-Hartmann sensor, and a calculation unit configured to calculate the change in the height of the object by using the change in the reflected light detected by the light sensing unit; a second light source configured to emit laser light for processing to the object; and a focus adjusting device configured to adjust a focus of the laser light emitted to the object by using the change in the height of the object to be processed measured by the measuring device.

Abstract: The system includes a dual interferometer sub-system configured to measure flatness across a substrate. The system includes a mass sensor configured to measure the mass of the substrate. The system includes a controller communicatively coupled to the dual interferometer sub-system and the mass sensor. The controller includes one or more processors. The one or more processors are configured to execute a set of program instructions stored in memory, the set of program instructions configured to cause the one or more processors to determine a thickness distribution of at least one of the substrate or a film deposited on the substrate as a function of position across the substrate based on one or more flatness measurements from the dual interferometer sub-system and one or more mass measurements from the mass sensor.

Abstract: A method for determining characteristics of a test cavity, the method includes for each of a plurality of optical frequencies within a bandwidth of a tunable laser, measuring interference signals from the test cavity and a reference cavity having a known characteristic. The method includes determining values for the plurality of optical frequencies from the measured interference signals from the reference cavity and the known characteristic of the reference cavity, and determining the characteristic of the test cavity using the determined values of the plurality of optical frequencies.

Abstract: Embodiments described herein relate to systems and methods for specular surface inspection, and particularly to systems and methods for surface inspection comprising inverse synthetic aperture imaging (“ISAI”) and specular surface geometry imaging (“SSGI”). Embodiments may allow an object under inspection, to be observed, imaged and processed while continuing to be in motion. Further, multiple optical input sources may be provided, such that the object does not have to be in full view of all optical sensors at once. Further, multi-stage surface inspection may be provided, wherein an object under inspection may be inspected at multiple stages of an inspection system, such as, for an automotive painting process, inspection at primer, inspection at paint, inspection at final assembly. SSGI imaging modules are also described for carrying out micro-deflectometry.

Abstract: A system and methods for quantitative optical phase imaging of a sample. First second replica field of an image field are generated, characterized by a respective optical phase, cross-polarized and shifted in a shift direction transverse to a normal to the surface of the sample. The replica fields are Fourier transformed, the second replica field is retarded by four successive phase shifts, and, after inverse Fourier transforming, the first and second replica fields pass through an analyzer polarizer and superposing the first and second replica fields on a detector array to create four successive detector signals. The four successive detector signals are solved to derive a gradient of the optical phase of the image field, which may be integrated to obtain a quantitative phase image.

Abstract: In one embodiment, a color holographic image is created by generating a separate complex hologram for each of multiple different colors of an object field illuminated with incoherent light, combining the separate complex holograms to obtain a color complex hologram, and generating a reconstructed color holographic image of the object field.

Abstract: An image measurement device according to the present invention comprises: a stage on which a measurement object is mounted; an imaging device imaging the measurement object for a certain imaging range and outputting image information; a position control device that moves the imaging device to a plurality of measurement positions and scans in a scanning direction; and an arithmetic processing device that calculates a displacement of the measurement object. The imaging device is configured capable of imaging a preliminary measurement range broader than the certain imaging range. The arithmetic processing device, prior to a main measurement that measures the displacement of the measurement object at each measurement position, makes a preliminary measurement based on the image information corresponding to the preliminary measurement range, and sets a scanning range of the imaging device at each measurement position during the main measurement based on a result of this preliminary measurement.

Abstract: Methods and systems are provided for using optical interferometry in the context of material modification processes such as surgical laser or welding applications. An imaging optical source that produces imaging light. A feedback controller controls at least one processing parameter of the material modification process based on an interferometry output generated using the imaging light. A method of processing interferograms is provided based on homodyne filtering. A method of generating a record of a material modification process using an interferometry output is provided.

Abstract: Provided is an optical measurement system. The optical measurement system includes: an optical module which includes an optical system and which is configured to illuminate a sample and register a defocused image of a nanostructured surface of the sample, an optical system parameter control module configured to set optical parameters of the optical system, an optical transfer function (OTF) measurement module configured to measure an OTF, a defocused image calculation module configured to calculate the defocused image based on the measured OTF and the optical parameters, and a critical dimension (CD) evaluation module configured to compare the registered defocused image with the calculated defocused image of the nanostructured surface of the sample and to output a CD value of the nanostructured surface.

Abstract: The phase modulation device (3) includes a first phase modulation element (11) which modulates a phase of a light flux in accordance with a voltage applied to each of a plurality of first electrodes in accordance with a first ratio of a second aberration component to a first aberration component of a wave front aberration generated by an optical system including an objective lens (4); a second phase modulation element (12) which modulates a phase of a light flux in accordance with a voltage applied to each of a plurality of second electrodes in accordance with a second ratio of the second aberration component to the first aberration component; and a control circuit (3) which controls voltages applied to each of first electrodes and each of second electrodes in accordance with a distance from the objective lens to a light focusing position of the light flux.

Abstract: Hybrid sensors comprising Shack-Hartmann Wavefront Sensor (S-HWFS) and Zernike Wavefront Sensor (Z-WFS) capabilities are presented. The hybrid sensor includes a Z-WFS optically arranged in-line with a S-HWFS such that the combined wavefront sensor operates across a wide dynamic range and noise conditions. The Z-WFS may include the ability to introduce a dynamic phase shift in both transmissive and reflective modes.

Abstract: An apparatus for measuring the optical performance characteristics and dimensions of an optical element comprising a low coherence interferometer and a Shack-Hartmann wavefront sensor comprising a light source, a plurality of lenslets, and a sensor array is disclosed. The low coherence interferometer is configured to direct a measurement beam along a central axis of the optical element, and to measure the thickness of the center of the optical element. The light source of the Shack-Hartmann wavefront sensor is configured to emit a waveform directed parallel to and surrounding the measurement beam of the interferometer, through the plurality of lenslets, and to the sensor array. A method for measuring the optical performance characteristics and dimensions of a lens using the apparatus is also disclosed.

Abstract: A semiconductor measuring tool has a folding mirror configuration that directs a light beam to pass the same space multiple times to reduce the size and footprint. Furthermore, the folding mirrors may reflect the light beam at less than forty-five degrees; thereby allowing for smaller folding mirrors as compared to the prior art.

Abstract: A displacement measuring device includes an optical module for refracting or reflecting light; a beam splitting module including a polarizing beam splitting layer for allowing light with a first polarization direction to pass through and reflecting light with a second polarization direction; a light source for generating a first light beam with the first polarization direction and a second light beam with the second polarization direction, wherein the first light beam is reflected by a measured object after passing through the optical module and the beam splitting module, and the second light beam is reflected by the polarizing beam splitting layer after passing through the optical module; an image sensor for sensing an interference pattern generated by the reflected first and second light beams; and a processing unit for calculating a displacement value of the measured object according to the interference pattern.