Abstract: A measurement method of measuring a wavefront aberration of an optical system to be measured, comprising a first measurement step of measuring wavefronts of the optical system to be measured with respect to linearly polarized light beams along at least three different azimuths, a first calculation step of calculating a wavefront of the optical system to be measured with respect to non-polarized light and a birefringent characteristic of the optical system to be measured, based on the wavefronts of the optical system to be measured, which are measured in the first measurement step, and a second calculation step of calculating a wavefront of the optical system to be measured with respect to arbitrary polarized light, based on the wavefront and the birefringent characteristic of the optical system to be measured, which are calculated in the first calculation step.

Abstract: One embodiment of the present invention is a method to not limit the device's manipulation of the data to that of the manufacturer, but to allow greater freedom for customization by the individual user for their preference.

Abstract: An optical tomograph which irradiates and scans a measuring light beam onto a measurement target at a predetermined scanning frequency, to obtain a tomographic image of the measurement target is provided. A depolarizing unit, for varying the polarization state of light beams input thereto at a frequency equivalent to or higher than the scanning frequency, such that the light beam output therefrom becomes depolarized when averaged over time, is provided in the optical path of at least one of the measuring light beam, a reference light beam, and a reflected light beam between a light source unit and a combining unit.

Abstract: Optical coherence tomography (OCT) is an imaging method which can image with micrometer-scale resolution up to a few millimeters deep into, for example, living biological tissues and preserved tissue samples. An improved apparatus and image reconstruction algorithm for parallel Fourier Domain OCT which greatly eases requirements for interferometer stability and also allows for more efficient parallel image acquisition is provided. The apparatuses and algorithms reconstruct images from interfered, low-coherence, multiwave length signals having a ? radian phase difference relative to one another. Other numbers of signals and other phase differences may be alternatively used, with some combinations resulting in higher resolution and image stability. The apparatus also eliminates a need for bulk optics to modulate a phase delay in a reference arm of the optical path. Images may be reconstructed using two spectrometers, where each is coupled to a detector array such as a photodiode array.

Abstract: An optical characteristic measuring apparatus includes: a light source section which sweeps wavelengths of a first input light and a second input light respectively, frequencies of the first and second input lights being different from each other and polarized states of the first and second input lights being perpendicular to each other, and outputs the first and second input light; an interference section which inputs one branched light of the first and second input lights to a measuring object, makes output light from the measuring object interfere with other branched light of the first and second input lights, and outputs a plurality of interference lights; a plurality of light receiving sections which are respectively provided for the interference lights, receives the interference lights respectively, and outputs signals in accordance with optical powers of the interference lights respectively; and a low-pass filter for filtering the outputted signals.

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 exposure apparatus including an illumination system which illuminates an original, and projection optics which project a pattern of the original illuminated by the illumination system onto a substrate. The apparatus includes an interferometer which forms an interference pattern including aberration information on the projection optics using a polarized light beam emitted from the illumination system, in which the interferometer is a common path interferometer in which two light beams forming interference pattern pass along a path in the projection optics, and a processor which calculates optical characteristics of the projection optics on the basis of the interference pattern formed by the interferometer. The illumination system including a polarization controller which sequentially generates at least three difference polarized light beams with respective polarization states different from each other.

Abstract: A refractive-index measurement system includes a light source, a first beam splitter, a first reflective mirror, a second reflective mirror, a second beam splitter, a container, a first polarizer, and a second polarizer. The first beam splitter splits light emitted from the light source into first and second light beams. The first light beam and the second light beam are reflected by the first reflective mirror and the second reflective mirror, respectively, incident into the second light beam splitter. The container is positioned along an optical pathway of first light beam. The container accommodates a lens and is filled with a medium having a refractive index substantially the same as a theoretical refractive index of the lens. The first polarizer is positioned along the optical pathway of the first light beam. The second polarizer is positioned along an optical pathway of the second light beam.

Abstract: An oblique incidence interferometer has favorable measurement accuracy while achieving miniaturization. The oblique incidence interferometer includes a light source that emits coherent light; a beam dividing unit that divides the coherent light from the light source into a measurement beam and a reference beam, polarizing directions of both beams being perpendicular to each other; a first beam folding unit that folds the measurement beam divided by the beam dividing unit to cause the folded measurement beam to be incident on the measurement object surface at a predetermined angle relative to the measurement object surface; a second beam folding unit that folds the measurement beam reflected by the measurement object surface; and a beam combining unit that combines the measurement beam folded by the second beam folding unit with the reference beam.

Abstract: The present invention relates to a polarization interference microscope (1) for imaging objects (5). The polarization interference microscope (1) comprises a light source (2), an illumination beam path (6), an imaging beam path (7) and an objective (4). The illumination beam path (6) extends from the light source (2) to the object (5). The imaging beam path (7) extends from the object (5) to a detector or a tube (3). At least one polarization means (9) is provided in the illumination beam path (6) and/or in the imaging beam path (7), by which at least one polarization means the light of the respective beam path (6, 7) can be converted into a predeterminable polarization state. An analyzer means (10) is provided in the imaging beam path (7). A birefringent component is provided between the polarization means (9) and the analyzer means (10), by which birefringent component the light polarized by the polarization means (9) can be divided into two partial beams (13, 14) having different polarization directions.

Abstract: The present invention provides an OCT technique that permits tomographic observation of a biological body parts that is difficult to restrain and also provides a tomographic observation technique for the observation of a constrainable part that does not require constraint and remove the burden from biological body. A wavelength-tunable light generator (wavelength-tunable light source) is employed as the light source of the optical coherence tomography device. The wavelength-tunable light generator has a wave number tunable range width of at least 4.7×10?2 ?m?1 and an emitted-light frequency width of no more than 13 GHz, for example, and includes means capable of changing the wave number stepwise at wave number intervals of no more than 3.1×10?4 ?m?1 and time intervals of no more than 530 ?s.

Abstract: A surface shape measuring apparatus includes an illumination system and a light receiving system. The illumination system splits wide-band light from a light source into measurement light and reference light, illuminates the measurement light to obliquely enter a surface of the film, and illuminates the reference light to obliquely enter a reference mirror. The light receiving system combines the measurement light reflected by the surface of the film and the reference light reflected by the reference mirror with each other and introduces the combined light to a photoelectric conversion element. An incident angle of the measurement light upon the surface of the film and an incident angle of the reference light upon the reference mirror are each larger than the Brewster's angle. S-polarized light and p-polarized light included in the measurement light entering a surface of the substrate have equal intensity on the photoelectric conversion element.

Abstract: An apparatus for measuring surface topography of an object includes an optical arrangement capable of directing a first light beam at a surface of the object, providing a second light beam coherent with and spatially phase-shifted relative to the first light beam, and generating an interference beam from the second light beam and a reflection of the first light beam from the surface of the object. The apparatus further includes at least one line scan sensor for detecting and measuring the interference beam.

Abstract: In an optical tomography system, an interference light obtained by multiplexing the reflected light from the object and the reference light is guided to an interference light detecting means by a waveguide means. The interference light detecting means has a spectrometer spectrally dividing the interference light. A polarization setting means which causes the interference light guided by the waveguide means to enter the spectrometer after setting the state of polarization of the interference light guided by the waveguide means to a predetermined state of polarization is provided between the waveguide means and the spectrometer.

Abstract: An optical measuring apparatus for comprising, in combination, a polarization type interferometer including a polarization type beam splitter in which a polarized beam of light is split into orthogonally polarized reference and test beams, an array of detectors arranged in a line for creating a plurality of phase shifting interferograms, and a scanning device for moving the object in a direction perpendicular to a long axis of the detectors.

Abstract: The invention relates to an interferometric method for measuring a height of a first region on a first surface, the first surface having first areas having first optical properties and second areas having second optical properties, the method comprising the steps of generating of first and second coherent light beams, reflecting at least the first coherent light beam from the first region into a first return beam and reflecting the second coherent light beam from a second region into a second return beam, measuring at least a first reflectivity of the first region, determining a topography-dependent phase shift of the first and second return beams for the height measurement based on the first reflectivity.

Abstract: The invention relates to an interferometric method for measuring a height of a first region on a first surface, the first surface having first areas having first optical properties and second areas having second optical properties, the method comprising the steps of generating of first and second coherent light beams, reflecting at least the first coherent light beam from the first region into a first return beam and reflecting the second coherent light beam from a second region into a second return beam, measuring at least a first reflectivity of the first region, determining a topography-dependent phase shift of the first and second return beams for the height measurement based on the first reflectivity.

Abstract: Provided is an optical image measuring apparatus capable of obtaining a high-accuracy image without being influenced by a movement of an object to be measured. Flash light is emitted from a xenon lamp (2) and converted into broad band light by an optical filter (2A). A polarization characteristic of the flash light is converted into linear polarization by a polarizing plate (3). Then, the flash light is divided into signal light (S) and reference light (R) by a half mirror (6). A polarization characteristic of the reference light (R) is converted into circular polarization by a wavelength plate (7). The signal light (S) and the reference light (R) are superimposed on each other by the half mirror (6) to produce interference light (L). A CCD (23) detects interference light having the same characteristic as that of the produced interference light (L).

Abstract: Optical imaging systems are provided including a light source and a depolarizer. The light source is provided in a source arm of the optical imaging system. A depolarizer is coupled to the light source in the source arm of the optical imaging system and is configured to substantially depolarize the light from the light source. Related methods and controllers are also provided.

Abstract: A system for selectively blocking electromagnetic energy. The system includes a first mechanism for employing a perforated component to pass a beam characterized by a first property and reject a beam characterized by a second property. A second mechanism selectively alters a beam passed by the first mechanism so that upon reflection, the beam exhibits the second property. In a specific embodiment, the first property corresponds to a first polarization, and the second property corresponds to a second polarization. In the specific embodiment, the perforated component includes a beamsplitter having a first perforated metallic plate. The second mechanism includes a quarter-wave plate having a second perforated metallic plate.

Abstract: In one aspect, the disclosure features methods that include using a microscope to direct light to a test object and to direct the light reflected from the test object to a detector, where the light includes components having orthogonal polarization states, varying an optical path length difference (OPD) between the components of the light, acquiring an interference signal from the detector while varying the OPD between the components, and determining information about the test object based on the acquired interference signal.

Abstract: An oblique incidence interferometer is provided for applying a light at a certain angle from the normal to a measurement surface of a target to be measured and measuring a light reflected from the target. A beam splitter element and beam synthesizer element splits the light from a light source into a measurement light to be applied to the target and a reference light serving as the measurement reference. It also orthogonalizes the polarization directions of the measurement light reflected from the target and the reference light and synthesizes the lights. A three-way split prism splits the synthesized light into a plurality of split lights. Imaging units are provided to capture a plurality of interference fringe images formed in accordance with the plurality of split lights. A ¼-waveplate is provided on either one of an entry side and an exit side of the three-way split prism. Polarizers are provided on imaging surfaces of the imaging units.

Abstract: An optical image measuring apparatus including a light emitting portion outputting light having different wavelengths intensity-modulating the light periodically, a polarizing plate converting a light to linearly polarized light, a half mirror dividing the light into signal light and reference light, a wavelength plate converting a polarization characteristic of the reference light, a frequency shifter shifting a frequency of the reference light, the half mirror superimposing the signal light and the reference light on each other to produce interference light, a polarization beam splitter extracting a polarized light from the interference light, CCDs detecting the extracted polarized interference light, and a signal processing portion forming an image of an object to be measured based on the polarized interference light related to each of the lights, detected by the CCDs.

Abstract: Disclosed herein is an apparatus and method for measuring the thickness and profile of a transparent thin film using a white-light interferometer. The apparatus and method separate coherent light according to frequency, obtain a first interference pattern at each frequency, separate composite coherent light according to frequency, and obtain a second interference pattern at each frequency. Further, the apparatus and method obtain a phase, generated by the thickness of the thin film, from the first interference pattern, and acquire only information about the thickness of the thin film. Further, the apparatus and method obtain a phase from the second interference pattern, and acquires information about the profile of the thin film, including information about the thickness of the thin film. Further, by using the thin film thickness information, information about the profile of the thin film is acquired from the thin film profile information including the thin film thickness information.

Abstract: A method for irradiating onto a target optical system plural linearly polarized rays having different polarization directions, and for measuring a polarization characteristic of the target optical system including a birefringence amount R and a fast axis ? includes the steps of irradiating linearly polarized ray having a polarization direction ? onto the target optical system and obtaining a centroid amount P of the ray that has transmitted through the target optical system, and obtaining the birefringence amount R and the fast axis ? from P=?R·cos(2???) or P=R·cos(2???).

Abstract: A phase shifting imaging module in a handheld imager is provided. The phase shifting imaging module includes a first beam splitter configured to split an image radiation beam into first and second image radiation beams. It also includes a first prism configured to align the first and second image radiation beams, and a second beam splitter configured to split the first and second image radiation beams into four image radiation beams. A second prism aligns the four image radiation beams. A phase mask introduces phase retardation between the four image radiation beams, resulting in four phase shifted image radiation beams. A pixilated sensor generates image data based upon each of the four phase shifted image radiation beams.

Abstract: A tissue imaging system (200) for examining the medical condition of tissue (290) has an illumination optical system (205), which comprises a light source (220), having one or more light emitters, beam shaping optics, and polarizing optics. An optical beamsplitter (260) directs illumination light to an imaging sub-system, containing a spatial light modulator array (300). An objective lens (325) images illumination light from the spatial light modulator array to the tissue. An optical detection system (210) images the spatial light modulator to an optical detector array. A controller (360) drives the spatial light modulator to provide time variable arrangements of on-state pixels. The objective lens operates in a nominally telecentric manner relative to both the spatial light modulator and the tissue. The polarizing optics are independently and iteratively rotated to define variable polarization states relative to the tissue.

Abstract: An inspection apparatus is disclosed having an radiation system configured to provide an radiation beam, a beamnsplitter configured to create, from the radiation beam, a first illumination beam and a second illumination beam directed to a planar reference part of a sample and a patterned part of the sample, respectively, and a beam detector configured to detect a detection beam, the detection beam comprising a recombination of radiation scattered from the planar reference part and the patterned part.

Abstract: A method and an apparatus for shape measurement that is able to observe the deep portion under a skin with high spatial resolution by using a frequency COMB light generator is provided. A frequency COMB light generator for generating multiple frequency COMBs with variable frequency pitch at high operation stability is provided. This apparatus for shape measurement comprises a frequency COMB light generator and an optical interferometer for measuring the distance. The frequency COMB light generator includes a laser light source 11, an optical resonator 13, a COMB pitch regulator 14 and an output port OUT. The optical resonator 13 includes an optical modulator 131, a first mirror M11, an optical fiber F13 which is drawn out from alight waveguide of the optical modulator. The COMB pitch regulator 14 is a modulation signal generator for varying the modulation signal. The optical fiber F13 is equipped with an apparatus (Faraday rotation mirror) for compensating a change in the polarization condition.

Abstract: The present invention relates to vibration-insensitive point-diffraction interferometry. For the purpose of obtaining high immunity to vibration, a single-mode optical fiber is used to generate the reference wave, by means of point diffraction, directly from a measurement wave reflected from test objects. The capability of vibration desensitization is further strengthened by adding a spatial phase-shift device that enables four interferograms of different amounts of phase shift to be obtained simultaneously with no time delay between interferograms. The present invention may be effectively used in the design of measuring systems for in-line applications where measurements need to be performed in the presence of significant levels of vibration.

Abstract: A system and method for interferometric height measurement. A first coherent light beam and a second coherent light beam is generated. At least the first coherent light beam is reflected from a first region into a first return beam and the second coherent light beam is reflected from a second region into a second return beam. At least a first reflectivity of the first region is measured. A topography-dependent phase shift of the first return beam and the second return beam is determined with reference to a curve relating the first reflectivity to a material-dependent phase shift. A height based on the topography-dependent phase shift is measured.

Abstract: A phase shift interferometer (100) has an illuminating optical system (200) that emits a P-wave and an S-wave, a collimator lens (110), a reference half mirror (120), a pinhole plate (130) having a pinhole (131), and a phase shift interference fringe acquiring section (300) that allows an object light and a reference light contained in the light beam passed through the pinhole (131) interfere with each other in four different phases to acquire interference fringes with different phases. In the S-wave, only the reference light (SR) reflected by the reference half mirror (120) is passed through the pinhole (131), and the object light (SM) reflected by a surface-to-be-measured is blocked by the pinhole plate (130). In the P-wave, only the object light (PM) reflected by the surface-to-be-measured is passed through the pinhole (131), and the reference light (PR) reflected by the reference half mirror (120) is blocked by the pinhole plate (130).

Abstract: Provided is an optical image measuring apparatus capable of effectively receiving interference light, particularly an alternating current component thereof using a smaller number of photo sensors. The optical image measuring apparatus includes a polarizing plate for converting a light beam from a broad-band light source to linearly polarized light, a half mirror for dividing the light beam into signal light and reference light, a piezoelectric element for vibrating a reference mirror, a wavelength plate for converting the reference light to circularly polarized light, a polarization beam splitter for extracting two different polarized light components from interference light produced from the signal light and the reference light which are superimposed on each other by the half mirror, CCDs for detecting the two different polarized light components, and a signal processing portion for producing an image of an object to be measured based on the detected polarized light components.

Abstract: A system and method for coherent optical inspection are described. In one embodiment, an illuminating beam illuminates a sample, such as a semiconductor wafer, to generate a reflected beam. A reference beam then interferes with the reflected beam to generate an interference pattern at a detector, which records the interference pattern. The interference pattern may then be compared with a comparison image to determine differences between the interference pattern and the comparison image. According to another aspect, the phase difference between the reference beam and the reflected beam may be adjusted to enhance signal contrast. Another embodiment provides for using differential interference techniques to suppress a regular pattern in the sample.

Abstract: A method of detecting non-uniform ellipsometric properties of a substrate surface involving: directing a measurement beam onto a spot at a selected location on or in the substrate; for each orientation of a plurality of different orientations of the reference beam relative to the scattered measurement beam, interfering the scattered measurement beam with the reference beam to produce a corresponding interference beam, wherein each of the different orientations of the reference beam is selected to produce a peak sensitivity for a portion of the scattered measurement beam that emanates from the object at a corresponding different diffraction angle of a plurality of diffraction angles; for each orientation of the reference beam, converting the interference beam into an interference signal; and using the interference signals to determine whether any non-uniform ellipsometric properties are present anywhere within a region on or in the substrate.

Abstract: Scanning interferometry data for a test object is provided, the data typically including intensity values for each of multiple scan positions for each of different spatial locations of the test object. The intensity values for each spatial location define an interference signal for the spatial location, and the intensity values for a common scan position define a data set for that scan position. Scan values are provided for each scan position, in which scan value increments between various scan values can be non-uniform. Information is determined about the test object based on the scanning interferometry data and scan values. The determination includes transforming at least some of the interference signals into a frequency domain with respect to the scan values.

Abstract: A compact monolithic quadrature detector generates four signals from an input beam including orthogonally polarized object and reference beam components provided by an interferometer. The single input beam may be split into four output beams using a first beam splitting interface between two prisms, reflections at two air interface surfaces of the prisms, and a second beam splitting element. Different respective predetermined phase shifts may be imposed on the respective output beams by coatings on the beam splitting surfaces, which impart a different phase shift to the components of a transmitted beam as compared to a reflected beam. The four relatively phase shifted output beams may be directed through polarizers onto respective detectors to provide four signals usable to eliminate many common mode errors and determine the phase difference between the components of the original input beam with high accuracy.

Abstract: An optical image measuring apparatus capable of measuring an object to be measured which includes a birefringent layer in a short time is provided. The optical image measuring apparatus includes a broad-band light source, lenses for increasing a diameter of the light beam, a polarizing plate, a half mirror, a wavelength plate for converting the reference light to circularly polarized light, a wavelength plate for converting the signal light to circularly polarized light and converting the signal light to linearly polarized light, a frequency shifter, a polarization beam splitter for separating an S-polarized light component and a P-polarized light component from interference light, CCDs for receiving the respective polarized light components and outputting detection signals each including intensity change information, and a signal processing portion for forming an image reflecting a birefringent property, of an object to be measured based on the intensity change information.

Abstract: A common-path, point-diffraction, phase-shifting interferometer uses a half wave plate having a diffractive element, such as pin hole. A coherent, polarized light source simultaneously generates a reference beam from the diffractive element and an object beam from remaining portions of the light going through the half wave plate. The reference beam has a nearly spherical wavefront. Each of the two beams possesses a different polarization state. The object and reference beams are then independently phase modulated by a polarization sensitive phase modulator that shifts phase an amount depending on applied voltage and depending on polarization state of the incident light. A polarizer is then used to provide the object and reference beams in the same polarization state with equal intensities so they can interfere to create an interferogram with near unity contrast.

Abstract: A method of processing a substrate having an optical surface includes using an interferometer which includes optics for providing a beam of measuring light. The optics polarize the beam of measuring light such that a tangential polarization component continuously increases relative to a radial polarization component with increasing distance from an optical axis. The substrate is positioned in the beam of measuring light. Using the system, the interferometer determines a surface map of the optical surface, and determines deviations of the optical surface from a target shape.

Abstract: A method and an apparatus for the spatially resolved polarimetric examination of an imaging beam pencil (1) generated by an associated pulsed radiation source (9). A first and a second photoelastic modulator (6a, 6b) and a polarization element (5) are introduced serially into the beam path of the beam pencil. A control unit (8) activates a first modulation oscillation of the first photoelastic modulator and a second modulation oscillation of the second photoelastic modulator and drives the radiation source for outputting a respective radiation pulse in a manner dependent on the oscillation state of the first photoelastic modulator and/or the second photoelastic modulator. A detector (4) detects the beam pencil coming from the polarization element in a spatially resolved manner.

Abstract: A method for optical evaluation of a sample includes scanning a beam of coherent radiation over the sample, whereby the radiation is scattered from the sample, while directing a portion of the scanning beam toward a diffraction grating so that the portion of the beam is scanned over the grating, whereby a frequency-shifted reference beam is diffracted from the grating. The scattered radiation and the frequency-shifted reference beam are combined at a detector to generate an optical heterodyne signal.

Abstract: An interferometric profiler is used to measure object motion by modifying the motion of the scanner so that the phase variation at each scanning step is kept within the acceptable limits of the algorithm used to calculate phase changes. The scanner motion is so manipulated on the basis of prior knowledge about the nature of the object motion, or knowledge obtained by pre-calibration, or by real-time feedback based on current measurements. The object motion is recovered from the scanning information by subtracting the scanner position from the object position as it evolves during the scan.

Abstract: In accordance with the present invention, embodiments of interferometers are presented that improves both the polarization dependency problem and helps prevents light from being reflected back into the light source, among other things. Interferometer embodiments can include an isolator coupled to a light source and polarization dependent optics coupled with the isolator to provide light to a reference arm and a sample arm, wherein reflected light provided to optical detectors is such that a polarization independent optical signal can be formed in an optical signal processor coupled to the optical detectors, and the isolator blocks reflected light from the reference arm and the sample arm from entering the light source. In some embodiments, a balanced detection system can be utilized to reduce noise.

Abstract: A method for irradiating onto a target optical system plural linearly polarized rays having different polarization directions, and for measuring a polarization characteristic of the target optical system including a birefringence amount R and a fast axis ? includes the steps of irradiating linearly polarized ray having a polarization direction ? onto the target optical system and obtaining a centroid amount P of the ray that has transmitted through the target optical system, and obtaining the birefringence amount R and the fast axis ? from P=?R·cos(2???) or P=R·cos(2???).

Abstract: The tilted relationship between the reference and test mirrors (24,26) of a Fizeau interferometer is used to spatially separate the reflections (R,T) from the two surfaces. The separate beams (R,T) are filtered through a spatial polarization element (32) that provides different states of polarization to the beams. The beams (R,T) are subsequently recombined to form a substantially collinear beam that is processed using a spatial-phase-shift interferometer (44) that permits quantitative phase measurement in a single video frame. Alternatively, two beams (104,106) with orthogonal polarization are injected into the Fizeau cavity (20) at different angles, such that after reflection from the reference and test optics (24,26) they are substantially collinear. Unwanted reflections are blocked at the focal plane through the use of a circular aperture (112).

Abstract: A phase-difference sensor measures the spatially resolved difference in phase between orthogonally polarized reference and test wavefronts. The sensor is constructed as a pixelated phase-mask aligned to and imaged on a pixelated detector array. Each adjacent pixel of the phase-mask measures a predetermined relative phase shift between the orthogonally polarized reference and test beams. Thus, multiple phase-shifted interferograms can be synthesized at the same time by combining pixels with identical phase-shifts. The multiple phase-shifted interferograms can be combined to calculate standard parameters such as modulation index or average phase step. Any configuration of interferometer that produces orthogonally polarized reference and object beams may be combined with the phase-difference sensor of the invention to provide, single-shot, simultaneous phase-shifting measurements.

Abstract: Method of optical measuring the microrelief of an object using a modulation interference microscope. An input coherent monochromatic polarized light flux is split into an object light beam exposing the object and a reference beam. The light flux intensity is redistributed between the object and reference beams. Thereafter, polarization modulation is performed separately for the object beam and the reference beam. The polarized object beam is reflected onto the object plane to expose the object field. Amplitude modulation is performed by changing the intensity ratio between the object beam and the reference beam. A fraction of the light at a pixel caused by the object beam with respect to the total light falling on the pixel is determined.

Abstract: The invention relates to an interferometric method for measuring a height of a first region on a first surface, the first surface having first areas having first optical properties and second areas having second optical properties, the method comprising the steps of generating of first and second coherent light beams, reflecting at least the first coherent light beam from the first region into a first return beam and reflecting the second coherent light beam from a second region into a second return beam, measuring at least a first reflectivity of the first region, determining a topography-dependent phase shift of the first and second return beams for the height measurement based on the first reflectivity.

Abstract: An interferometer system includes a rhomboid assembly having a first optical stack and a second optical stack mounted on the first stack. The first stack includes a first prism having an angled face mounted to an angled face of a second prism. The interface between these angled faces includes a first polarizing beam-splitter. The second stack includes a third prism having an angled face mounted to an angled face of the fourth prism. The interface between these angled faces includes a second polarizing beam-splitter. First, second, third, and fourth wave plate elements are located in beam paths between the rhomboid assembly and at least one of a measurement optic and a reference optic. A redirecting optic is located at least adjacent to the vertical faces of the first and the third prisms.