Abstract: The interferometer 10 according to this disclosure includes: a first optical component 12 that splits each of the P polarization component and the S polarization component of the light to be measured into the first optical path R1 and the second optical path R2 and combines the light to be measured; a second optical component 13 placed in the first optical path; a third optical component 14 that splits the light to be measured into the P polarization component and the S polarization component; and a P polarization detector 11a and an S polarization detector 11b that respectively detect the P polarization component and the S polarization component split by the third optical component, wherein the second optical component has an optical surface that changes the propagation direction of the light to be measured and gives a phase difference between the P polarization component and the S polarization component.

Abstract: In some examples, a method may include receiving retroreflected light that indicates at least one retroreflective property of a retroreflective article, wherein retroreflected light is captured at a first distance. The method may include determining a first set of information based at least in part on the at least one retroreflective property of the retroreflective article. The method may include receiving, from the light capture device, an image that includes at least one object, wherein the image is captured at a second distance. The method may include determining, based at least in part on the spatially resolvable property, a second set of information that corresponds to the object in the image. The method may include performing, by a computing device, at least one operation based at least in part on the second set of information.

Abstract: The disclosure discloses a differential sinusoidal phase modulation laser interferometric nanometer displacement measuring apparatus and method. The beam output from the single-frequency laser is converted into a 45° linearly polarized beam after passing through the polarizer, then projected onto two sets of sinusoidal phase modulation interferometers consisting of the beam splitter, the electro-optic phase modulator, the half wave plate, three pyramid prisms, two polarization beam splitters, thereby forming measurement and reference interference signals which are received by two photodetectors. A high-frequency sinusoidal voltage signal is applied to the electro-optic phase modulator placed in the common reference arm of the two interferometers, thereby modulating the interference signal into a high-frequency AC signal. By detecting the difference between the phase change amounts of the two interference signals when the measured object moves, the measured displacement can be obtained.

Abstract: A heterodyne optical interferometer incorporates error correction elements to correct a cyclic error that may be present in an interferometric measurement. The cyclic error can be caused by various factors such as an imperfect polarization relationship between two wavelength components, deficiencies in optical propagation paths (such as light leakage), imperfect optical coatings, and/or imperfect components. The cyclic error, which typically manifests itself as erroneous displacement information characterized by a low velocity sinusoidal frequency component, can be reduced or eliminated by using birefringent optical elements and other optical elements to alter certain characteristics of one or both wavelength components and reduce light leakage components in one or more light propagation paths in the heterodyne optical interferometer.

Abstract: A defect detection device 10 is provided with: a laser light source 11 for irradiating laser light to a measurement region R of a surface of an inspection object S; a laser light source control unit 15 for controlling the laser light source so as to cause laser light to be outputted continuously or quasi-continuously for a time longer than a period of vibration generated in the inspection object; an interferometer (speckle shearing interferometer 14) for generating interference light in which reflected light of the laser light reflected in the measurement region and reference laser light emitted from the laser light source 11 interfere; a detector (image sensor 145) for detecting the intensity of the interference light for each point in the measurement region R; a phase shifter 143 for shifting the phase of the reflected laser light or the reference laser light; an integrated intensity pattern determination unit 16 for obtaining an integrated intensity obtained by integrating the intensity for each point over

Abstract: Devices and methods employing stationary homodyne interferometry to aid in the determination of the magnitude and polarity of electrophoretic mobility and zeta potential of particles are provided. The devices use an optical quadrature interferometer having a sample holder loadable with an electrophoresis sample chamber that may contain sample particles undergoing electrophoresis, the optical quadrature interferometer being configured to perform optical velocimetry on the particles and to generate a quadrature signal comprising characteristics related to the speeds and directions of the particles. The quadrature signal may be used to determine the speeds and directions of particles. The speeds and directions of particles may be used, together with other information, for the determination of the magnitudes and polarities of the electrophoretic mobility and zeta potential of the particles. Constraints on vibration, light source coherence length, and measurement resolution may be relaxed.

Abstract: Disclosed is a heterodyne laser interferometer based on an integrated secondary beam splitting component, which belongs to the technical field of laser application; the disclosure inputs two beams that are spatially separated and have different frequencies to the heterodyne laser interferometer based on the integrated secondary beam splitting component, wherein the integrated secondary beam splitting component includes two beam splitting surfaces that are spatially perpendicular to each other; and the two beam splitting surfaces are plated with a polarizing beam splitting film or a non-polarizing beam splitting film, and a measurement beam and a reference beam are the same in travel path length in the integrated secondary beam splitting component.

Abstract: A thickness measuring apparatus has a thickness measuring unit including a white light source, a diffracting mechanism that diffracts white light emitted from the white light source into diffracted light at time differences corresponding to the wavelengths of light components of the white light, a two-dimensional image sensor having a photodetection area that include a plurality of pixels for detecting return light reflected from upper and lower surfaces of a plate-shaped workpiece, a storage unit that stores, as a spectral interference waveform, intensities of the return light corresponding to the wavelengths of the light components successively received at the time differences by the pixels, and a waveform table recording therein a plurality of kinds of sample spectral interference waveforms corresponding to plate-shaped workpiece thicknesses.

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: Various balanced detection systems which reduce alignment requirements of free space optics based balanced detection configurations are discussed. One example system includes a light source, a beam divider, sample optics, return optics, and a processor. The light source generates a light beam. The beam divider separates the light beam into reference and sample arms. The sample optics deliver the light beam in the sample arm to a light scattering object to be imaged. The return optics direct light to a balanced detection system, which has a balanced detection beam divider for combining light scattered from the object and light from the reference arm and directing the combined light into two detection channels and two detectors for collecting the combined light in the two detection channels and generating signals in response thereto. The processor processes the signals and generates image data of the object based on the processed signals.

Abstract: An optics arrangement includes a polarized beam splitter arranged along an collection axis, a first quarter waveplate arranged along the collection axis, and a second quarter waveplate. The second quarter waveplate is arranged along the collection axis and is optically coupled to the first quarter waveplate by the polarized beam splitter to limit return of polarized illumination originating in a scene being illuminated for retroreflector detection. Retroreflector detectors and methods of imaging a scene are also described.

Abstract: A three-dimensional measurement device includes a light source unit that emits distance measurement light, a projection light optical system that causes the distance measurement light, emitted by the light source unit, to be emitted along a distance measurement light axis, a light receiving optical unit that receives the reflected distance measurement light, a light receiving and splitting unit that splits the reflected distance measurement light that has transmitted through the light receiving optical unit into first reflected split light and second reflected split light, attenuates intensity of the second reflected split light to be lower than intensity of the first reflected split light, and converts the first reflected split light and the second reflected split light into electrical signals, and angle detection units that detect a light emitting direction of the distance measurement light.

Abstract: A system for detecting pressure, acoustic or ultrasound waves within an entity having a surface including the steps of attaching a signal converting material to the surface. The waves are generated by direct ejection from the surface, generation via energy deposition on the surface, generated spontaneously or, generated by directing light energy to the light absorbing target. The absorbing target subsequently generates acoustic pressure waves. The acoustic waves propagate to the surface of the entity and the signal converting material, wherein the acoustic pressure waves create vibrations in the signal converting material; and detecting the waves in the signal converting material with an optical detection system. Information about the absorbing target is obtained by the absorbing target reflecting the waves. The signal converting material can be a gel-like material containing optical elements, a multi-layer patch, or other material.

Abstract: Technologies for detecting absorption of electromagnetic radiation traveling through a measurement volume of interest are described herein. In a general embodiment, a laser is used to emit electromagnetic radiation through the measurement volume where absorption is desirably detected. An optical collector receives a portion of the radiation and directs a first fraction of the portion back to a gain medium of the laser, where the radiation is amplified and emitted again, and directs a second fraction to an optical sensor that can detect absorption in the measurement volume based upon attenuation of energy of the radiation. As the radiation feeds back to the gain medium and is emitted again, energy at attenuated wavelengths is amplified less than at other wavelengths. Thus, attenuation of energy of the radiation due to absorption in the measurement volume is cumulative, and relatively small absorptions are amplified, allowing smaller absorptions to be detected more easily.

Abstract: An interference observation apparatus includes a light source, a splitting beam splitter, a combining beam splitter, a beam splitter, a mirror, a beam splitter, a mirror, a piezo element, a stage, an imaging unit, an image acquisition unit, and a control unit. An interference optical system from the splitting beam splitter to the combining beam splitter forms a Mach-Zehnder interferometer. The mirror freely moves in a direction perpendicular to a reflecting surface of the mirror. The total number of times of respective reflections of first split light and second split light in the interference optical system is an even number.

Abstract: The present invention discloses a dual-homodyne laser interferometric nanometer displacement measuring apparatus and method based on phase modulation. The linearly polarized beam with single wavelength emitted from a single frequency laser is projected onto a dual-homodyne laser interferometer consisting of four beam splitters and two retroreflectors to respectively form a measurement interference signal and a reference interference signal received by two photodetectors, respectively; an electro-optic phase modulator is placed in the optical path and a periodic sawtooth-wave voltage signal is applied to modulate the measurement and reference DC interference signals into AC interference signals; the measured displacement is obtained by detecting the variation of the phase difference between the two interference signals caused by the movement of the measured object.

Abstract: Described herein is an apparatus for non-destructive testing that includes a cavity. The apparatus also includes an input element coupled with the cavity and configured to receive a laser beam and to direct the laser beam into the cavity. The apparatus additionally includes multiple output elements formed in the cavity and spaced apart along the cavity. Each output element of the multiple output elements is configured to direct a portion of the laser beam out of the cavity such that each portion of the laser beam directed out of a respective one of the multiple output elements has a substantially similar intensity.

Abstract: Methods and related apparatus (SP) to correct phase shift image data for phase wrapping artifacts. The data is detected at a detector (D) of an imaging system (IM) including interferometric equipment (G0, G1, G2). In a phase unwrapping method that involves optimizing an objective function with regularization, a two-sage approach is proposed. The measured data is processed in one stage with regularization and in the other stage without regularization. This allows improving the accuracy of the corrected (phase unwrapped) phase shift data because an undesirable bias caused by the regularization can be avoided.

Abstract: A real-time wavelength correction system for visible light is co-operated with an optical system to make a parallel light beam split into a zero-order diffractive parallel light beam and a first-order diffractive parallel light beam. The zero-order diffractive parallel light beam focuses on a first back focal plane to form a first light spot. A drift of the first light spot is applied to determine an angular drift of the parallel light beam. The first-order diffractive parallel light beam is focused on a second back focal plane to form a second light spot. A drift of the second light spot is applied to determine an angular drift of the first-order diffractive parallel light beam. The angular drifts of the parallel light beam and the first-order diffractive parallel light beam, which are changed with real time temperature variation, are applied to correct the wavelength of the parallel light beam.

Abstract: A method for detecting an alignment film coated on a substrate of a liquid crystal panel comprises: obtaining an image of an alignment film test region of a substrate; and analyzing continuity of the alignment film along an internal boundary of the alignment film test region in the image obtained. since the alignment film test region is located outside an active display area of the substrate, when the alignment film along the internal boundary of the alignment film test region is determined as continuous, it can be determined that all the edges of the alignment film are outside the active display area, then a Haro region which might appear on the edge of the alignment film may also be located outside the active display area, so as to ensure uniform thickness of the alignment film in the active display area of the substrate.

Abstract: Apparatus and method for curvature and thin film stress measurement are disclosed. The apparatus comprises two light sources and a detector. Two light beams from the two light sources with an angle are not parallel. The two light beams are collimated and projected onto a specimen with a pitch. The detector receives the light beams reflected from the specimen. The curvature of the specimen is calculated via a distance between spots of the light beams on the detector or a size variation of one of the spots.

Abstract: [Problem] To provide a low-cost, high-precision three-dimensional shape measuring device using vibration-resistant phase shift digital holography.

Abstract: The invention relates to an optical system for a microlithographic projection exposure apparatus, and to a microlithographic exposure method. An optical system for a microlithographic projection exposure apparatus comprises at least one mirror arrangement having a plurality of mirror elements, wherein these mirror elements can be adjusted independently of one another for changing an angular distribution of the light reflected by the mirror arrangement, and a polarization-influencing optical arrangement which is arranged downstream of the mirror arrangement in the light propagation direction, wherein the polarization-influencing optical arrangement reflects a light beam incident on the arrangement in at least two reflections, which do not occur in a common plane, for at least one angular distribution of the light reflected by the mirror arrangement.

Abstract: A property measurement system for a metal material includes: a laser oscillator that emits a pulse laser beam; a lens array that has small lenses with a same shape, the small lenses being laid in a matrix on a plane perpendicular to an optical axis of the pulse laser beam, and arranged so that a part of a cross section of the pulse laser beam can be made incident onto each of small lenses; a condensing lens that overlaps and condenses emitted beams coming from the small lenses on a same region of a surface of a metal material as a measurement target; a laser interferometer that detects, as an electric signal, a pulse ultrasonic wave that is excited by the pulse laser beam condensed and propagates through an inside of the metal material; and a signal processing device that processes the electric signal.

Abstract: The invention relates to an optical system for a microlithographic projection exposure apparatus, and to a microlithographic exposure method. An optical system for a microlithographic projection exposure apparatus comprises at least one mirror arrangement having a plurality of mirror elements, wherein these mirror elements can be adjusted independently of one another for changing an angular distribution of the light reflected by the mirror arrangement, and a polarization-influencing optical arrangement which is arranged downstream of the mirror arrangement in the light propagation direction, wherein the polarization-influencing optical arrangement reflects a light beam incident on the arrangement in at least two reflections, which do not occur in a common plane, for at least one angular distribution of the light reflected by the mirror arrangement.

Abstract: Apparatus, method and storage medium which can provide at least one first electro-magnetic radiation to a sample and at least one second electromagnetic radiation to a reference, such that the first and/or second electromagnetic radiations have a spectrum which changes over time. In addition, a first polarization component of at least one third radiation associated with the first radiation can be combined with a second polarization component of at least one fourth radiation associated with the second radiation with one another. The first and second polarizations may be specifically controlled to be at least approximately orthogonal to one another.

Abstract: An interferometer apparatus for an optical fiber system and method of use is described. The interferometer comprises an optical coupler and optical fibers which define first and second optical paths. Light propagating in the first and second optical paths is reflected back to the optical coupler to generate an interference signal. First, second and third interference signal components are directed towards respective first, second and third photodetectors. The third photodetector is connected to the coupler via a non-reciprocal optical device and is configured to measure the intensity of the third interference signal component directed back towards the input fiber. Methods of use in applications to monitoring acoustic perturbations and a calibration method are described.

Abstract: Swing-style demodulation device for measuring displacement information, including (1) a broadband light source, (2) an optical circulator, (3) GRIN lens, (4) a fixed mirror on an object under test, (5) a collimating device, (6) a rotating mirror, (7) f-? lens, (8) a polarizer, (9) a narrow strip shaped birefringent wedge, (10) a polarization analyzer, and (11) a signal acquisition system.

Abstract: In measuring the displacement of an object using the phase-shifting light interference, since three beam splitters were used for generating the four phase-shifting optical paths, an interferometer was increased in size, whereby the application objects were limited.

Abstract: A system for sensing the position of a movable object includes a polarization maintaining fiber configured to receive light from a light source; an optical system configured to rotate an angle of polarization of the light by a first predetermined angle; a low birefringence fiber connected to the optical system at a first end and having a mirror connected to a second end configured to reflect the light and rotate the angle of polarization at a second predetermined angle, the second end being configured to overlap a magnetic field of the a magnet attached to the object. The angle of polarization is rotated to a third predetermined angle proportional to at least one of the strength of the magnetic field and an amount of the overlap. The optical system is configured to decompose the third predetermined angle into a first component and a second component. A detector is configured to detect a differential between the first and second components indicative of the amount of the overlap.

Abstract: This invention provides a swing-style and high signal-to-noise ratio low coherence interference demodulation devices and the corresponding demodulation method for the measurement of displacement. In the displacement sensing method, the optical path difference, which is built by the light reflections from the reference surface and the test object, varies with the displacement of the test object. When the reflected signal lights is sent to a low coherence polarization interference system, the birefringent wedge formulates a spatial distribution of optical path difference, from which the optical path difference of the reflection signals thus can be demodulated. In the displacement scanning method, the reflected signal lights are collimated and transferred to a time scanner consisting of a rotating mirror and a f-? lens, to perform thin light beam scanning along the longitudinal direction of a birefringent wedge.

Abstract: A distance measuring method for measuring surfaces uses a laser source having a frequency that can be modulated to tune a wavelength of a laser beam in a wavelength range. The laser beam is generated with a coherence length to provide a measuring beam and is emitted at the surface, located within a specified distance range, as a measuring beam. The measuring beam is back-scattered by the surface and is received again and used to interferometrically measure the distance from a reference point to the surface. The specified distance range lies at least partly outside of the coherence length. One portion of the laser beam is temporally delayed with respect to another portion, such that the one optical path difference caused by the delay matches the optical path difference that corresponds to a distance in the specified distance range plus or minus the coherence length of the laser.

Abstract: Measurement of motion errors of a linear stage is performed to enable accurate measurement of motion errors in linear directions and a rotational direction in the linear stage using a diffraction grating. A first beam splitter splits a laser beam emitted from a light emitting unit. A first measurement unit measures a unidirectional linear motion error of the linear stage using one laser beam component split by the first beam splitter and a second measurement unit measures an angular motion error and another unidirectional linear motion of the linear stage error using a diffracted beam component obtained by diffracting another laser beam component split by the first beam splitter through the diffraction grating. A third measurement unit circularly polarizes the beam component diffracted through the diffraction grating to measure a third unidirectional linear motion error of the linear stage.

Abstract: The invention relates to an optical sensor arrangement comprising a measuring optical fiber demonstrating birefringence modifiable as a function of a measurement variable, and to an optical analysis unit having two optical branches implemented as optical fibers forming a Mach-Zehnder interferometer and an optical coupler for bringing together light guided in the two branches, wherein at least one output of the coupler is optically connected to at least one light-sensitive element, and wherein the analysis unit comprises a polarizing beam splitter from which the optical branches originate, wherein the measurement optical fiber is connected upstream of an optical input of the polarizing beam splitter, and wherein a polarization converter is disposed in a course of one of the optical branches. The invention further relates to a detection method that can be performed using said sensor arrangement.

Abstract: In a displacement measurement apparatus using light interference, a probe light path is spatially separated from a reference light path. Therefore, when a temperature or refractive index distribution by a fluctuation of air or the like, or a mechanical vibration is generated, an optical path difference fluctuates between both of the optical paths, and a measurement error is generated. In the solution, an optical axis of probe light is brought close to that of reference light by a distance which is not influenced by any disturbance, a sample is irradiated with the probe light, a reference surface is irradiated with the reference light, reflected light beams are allowed to interfere with each other, and a displacement of the sample is obtained from the resultant interference light to thereby prevent the measurement error from being generated by the fluctuation of the optical path difference.

Abstract: A laser interferometer (10) comprises: a first beam splitter (22) which splits a laser beam emitted from a light source (3) into a first beam (L2) and a second beam; a second beam splitter (24) which splits the second beam into a third beam (L1) and a fourth beam (L3), and which causes reflected beams, produced by reflection of the split beams (L1, L3) and incident from reverse directions to the directions of the split beams, to exit in a reverse direction to the direction of the second beam; and a beam selecting unit (50, 51, 60, 66, 68) which, from among the reflected beams produced by reflection of the third and fourth beams (L1, L3) and caused to exit the second beam splitter (24) in the reverse direction to the direction of the second beam, selects a beam to be combined in the first beam splitter (22) with a reflected beam produced by reflection of the first beam (L2) and incident on the first beam splitter from a reverse direction to the direction of the first beam (L2).

Abstract: A displacement measurement method, an apparatus thereof, and a probe microscope. which enable stable measure an amount of displacement and a moving distance of an object under measurement with an accuracy of the sub-nanometer order or below without being affected by disturbances such as fluctuations of air and mechanical vibration. A pulsed beam is split into two; one beam is reflected by an object under measurement and then inputted to a delay optical path equivalent to one pulse period; and the other beam is sent through the same delay optical path in the opposite direction up to the object under measurement with a delay of one pulse period, and then reflected by the object under measurement. An optical phase variation caused by the movement of the object under measurement is obtained by subjecting the two pulsed beams to interference.

Abstract: A distance measuring apparatus and method that enable high-precision and high-speed measurement by canceling variations of a delay circuit in the apparatus are provided. Pulsed light is branched into first and second reference light, and transmitted measurement light, and the difference in detection time among the first reference light along a first path with no optical variations, the second reference light along a second path with an optical delay, and received measurement light from an object to be measured is measured. The received measurement light and the first reference light are temporally separate, distance is calculated from the difference in detection time between the received measurement light and the first reference light.

Abstract: The present invention provides a measuring apparatus for measuring an absolute distance between a reference surface an d a test surface, including a phase detection unit configured to detect an interference signal between light reflected by the reference surface and light reflected by the test surface, and detect, from the interference signal, a phase corresponding to an optical path length between the reference surface and the test surface, and a processing unit configured to perform processing of obtaining the absolute distance by controlling the phase detection unit so as to detect the phase corresponding to the optical path length between the reference surface and the test surface for each of a first reference wavelength and a second reference wavelength while changing the wavelength of light to be emitted by a first light source continuously from the first reference wavelength to the second reference wavelength.

Abstract: A tracking type laser gauge interferometer includes: a first recursive reflector configured to reflect light parallel to incident light; a second recursive reflector attached to a measurement object; a main body part configured to guide light emitted from a laser light source to the first recursive reflector; a rotating mechanism configured to rotate the main body part; and a control unit configured to control the rotating mechanism based on the light emergent from the main body part and reflected at the second recursive reflector, wherein: the main body part includes a light receiving element configured to receive the light reflected at the first recursive reflector and detect a position of the received light; and the control device includes: an angle acquisition unit configured to acquire a rotational angle of the rotating mechanism; and an correction unit configured to correct a motion error of the rotating mechanism.

Abstract: A dynamic probe detection system (29,32) is for use with a scanning probe microscope of the type that includes a probe (18) that is moved repeatedly towards and away from a sample surface. As a sample surface is scanned, an interferometer (88) generates an output height signal indicative of a path difference between light reflected from the probe (80a,80b,80c) and a height reference beam. Signal processing apparatus monitors the height signal and derives a measurement for each oscillation cycle that is indicative of the height of the probe. This enables extraction of a measurement that represents the height of the sample, without recourse to averaging or filtering, that may be used to form an image of the sample. The detection system may also include a feedback mechanism that is operable to maintain the average value of a feedback parameter at a set level.

Abstract: A multi-beam interferometer displacement measuring system has a light source module, a resonator module and a detecting device. The light source module has an emitter and a polaroid sheet. The emitter emits a non-polarizing beam. The polaroid sheet receives and transforms the non-polarizing beam into a polarizing beam. The resonator module receives the polarizing beam and has a coated glass panel, a corner cube prism and a wave-delay plate. The coated glass panel receives and reflects the polarizing beam. The corner cube prism receives and reflects the polarizing beam to the coated glass panel to form a resonant cavity. The wave-delay plate is mounted between the coated glass panel and the corner cube prism to receive the polarizing beam. The detecting device faces the coated glass panel to receive the interferential stripes formed in the resonator module and has a polarizing beam splitter, two power detectors and a signal processor.

Abstract: In a method for processing a workpiece in a tool machine, a first step (Step S4) for continuously measuring a position of a tip portion of a tool attached to a main axis, a second step (Step S5) for computing a displacement amount of the position of the tip point of the tool based on a result of the measurement, a third step (Step S8) for observing a time period while the displace amount is belonged in arrange of allowable displace amount previously determined, a fourth step (Step S9) for keeping an idling operation in case that the time for which the displace amount is belonged in the range of the allowable displacement amount is shorter than a time period previously determined and intermitting the idling operation in the case that the time for which the displace amount is belonged in the range of the allowable displacement amount become the time period previously determined and a fifth step (Step S10) for starting a process with respect to the workpiece in the case that the idling operation is finished are

Abstract: An accelerometer instrument is provided for measuring acceleration. The instrument includes a laser, a Mach-Zender interferometer (MZI), a mechanical spring, a detector, a camera, and an analyzer. The laser emits a coherent light beam of photons. The MZI includes first and second beam-splitters along with first and second mirrors. The first mirror has an established mass m and connects to the spring for vibrating substantially perpendicular to its reflection plane. The mechanical spring has an established spring constant k. The MZI has an established weak measurement Nw based on a known offset ? for the beam-splitters. The detector detects the beam beyond the second beam-splitter. The camera provides a pointer measurement shift ?q of the photons. The camera is disposed after the detector. The analyzer determines the acceleration ? based on a = ( k mN w ) ? ? ? ? q .

Abstract: Measurement of motion errors of a linear stage is performed to enable accurate measurement of motion errors in linear directions and a rotational direction in the linear stage using a diffraction grating. A first beam splitter splits a laser beam emitted from a light emitting unit. A first measurement unit measures a unidirectional linear motion error of the linear stage using one laser beam component split by the first beam splitter and a second measurement unit measures an angular motion error and another unidirectional linear motion of the linear stage error using a diffracted beam component obtained by diffracting another laser beam component split by the first beam splitter through the diffraction grating. A third measurement unit circularly polarizes the beam component diffracted through the diffraction grating to measure a third unidirectional linear motion error of the linear stage.

Abstract: The present invention provides a displacement measurement method, an apparatus thereof, a probe microscope. which make it possible to stably measure an amount of displacement and a moving distance of an object under measurement with an accuracy of the sub-nanometer order or below without being affected by disturbances such as fluctuations of air, mechanical vibration. Specifically, with the present invention, a pulsed beam is split into two; one beam is reflected by an object under measurement and then inputted to a delay optical path equivalent to one pulse period; and the other beam is sent through the same delay optical path in the opposite direction up to the object under measurement with a delay of one pulse period, and then reflected by the object under measurement. Then, an optical phase variation caused by the movement of the object under measurement is obtained by subjecting the two pulsed beams to interference.

Abstract: Systems and methods are disclosed for an interferometer system. An interferometer system may comprise a plurality of light sources, wherein each light source of the plurality is configured to transmit a source beam. The interferometer system may also include an interferometer including a polarizing beam splitter and a reference reflector. The interferometer is configured to receive the source beam and transmit a measurement beam to a target reflector and a reference beam to the reference reflector. Additionally, the interferometer system may include a plurality of receivers, wherein each receiver of the plurality is associated with a light source and configured to receive a mixed beam comprising a reflected measurement beam and a reflected reference beam. Moreover, the interferometer is configured to receive at least one source beam at an angle with respect to an axis perpendicular to a side of the interferometer configured to receive the source beam.

Abstract: A The local probe microscopy apparatus (1) comprises a probe (3) with translation stages (5a, 5b) for controlling the position of the probe (3) relative to a sample surface. The probe (3) has a feedback mechanism (6, 5 7) for maintaining the deflection of the probe and a height measuring system (9) which includes means for compensating for environmental noise. The local probe microscopy apparatus is particularly suitable for use as a wafer inspection tool in a wafer fabrication plant where the inspection tool is liable to be exposed to significant mechanical vibration.

Abstract: A method and a device for dynamic measurement of the radial deformation of a bearing ring (12) of a rolling bearing (10) for a rotating element (16), a glass fiber segment (22) of a fiber optic sensor (24) that is fixed in or to the periphery of the bearing ring, a light signal which has been generated by the light source (30) being injected into the glass fiber segment, and the light signal passing through the glass fiber segment being detected by a detector (34), the longitudinal deformation of the glass fiber segment being determined from the change of at least one parameter of the light signal, when the light signal passes through the glass fiber segment, in order to determine the corresponding radial deformation of the bearing ring.

Abstract: In a displacement measurement apparatus using light interference, a probe light path is spatially separated from a reference light path. Therefore, when a temperature or refractive index distribution by a fluctuation of air or the like, or a mechanical vibration is generated, an optical path difference fluctuates between both of the optical paths, and a measurement error is generated. In the solution, an optical axis of probe light is brought close to that of reference light by a distance which is not influenced by any disturbance, a sample is irradiated with the probe light, a reference surface is irradiated with the reference light, reflected light beams are allowed to interfere with each other, and a displacement of the sample is obtained from the resultant interference light to thereby prevent the measurement error from being generated by the fluctuation of the optical path difference.