Abstract: A scanning, self-referencing interferometer may include a scanning mechanism to scan a path length of a test beam portion of a laser beam. The scanning, self-referencing interferometer may also include a beam adjustment mechanism to control positioning of a centroid of a reference beam portion of the laser beam in the interferometer.

Abstract: Methods, systems, and computer program products for performing real-time quadrature projection based FDOCT are disclosed. According to one method, a plurality of interferogram signals is phase shifted. A Fourier transform is applied to each of the plurality of interferogram signals. Depth dependence of the plurality of transformed interferogram signals is then removed. A real quadrature component and an imaginary quadrature component for each of the plurality of transformed interferogram signals are subsequently calculated. The real quadrature components of the transformed interferogram signals are combined to obtain a derived real component and the imaginary quadrature components of the transformed interferogram signals are combined to obtain a derived imaginary component. A full-range depth profile of the object is constructed by adding the derived real component to the product of the derived imaginary component and a scaling factor.

Abstract: An optical image measurement device comprises: a light source configured to emit a low-coherence light; an interference-light generator configured to generate an interference light, by splitting the low-coherence light into a signal light and a reference light, and superimposing the signal light passed through a measurement object and the reference light passed through a reference object; a changer configured to change a difference in optical path length; a detector configured to detect the interference light; an image forming part configured to form an image of the measurement object within a predetermined frame based on the result of the detection; an analyzer configured to analyze the image, and specify a position of the image within the frame; and a controller configured to control the changer based on the specified position to change the difference so that an image newly formed is placed in a predetermined position within the frame.

Abstract: The present invention provides a three-dimensional shape measurement method and a three-dimensional shape measurement apparatus. Color luminance data I (x, y) is separated by an arithmetic processing unit into R, G and B which are color components of a color image. Then, maximum amplitude values are calculated, and the maximum values are composed to obtain an in-focus color omnifocal image. Further, a Z-position corresponding to the maximum amplitude value in an interferogram is calculated in at least one color component, and this processing is performed for all pixels (x, y) to calculate height information for a sample. The height information is provided to the color omnifocal image, such that the three-dimensional shape of the sample can be measured.

Abstract: Included in this disclosure is a quantum positioning system (QPS) that includes a corner cube reflector and a plurality of baselines. Each baseline may include an interferometer, which may include a photon source, a beam splitter, and a photon detector. The interferometer is configured for creating a bi-photon pair and initiating communication of the bi-photon pair with the corner cube reflector. Also included in the QPS is a positioning device configured to calculate a user's position.

Abstract: An optical tomograph obtains tomographic images by administering frequency analysis on an interference light beam formed by interference between a reflected light beam, which is a measuring light beam reflected by a measurement target, and a reference light beam. A tomographic data obtaining section obtains tomographic data to be used for optical path length adjustment each time that the position, onto which the measuring light beam is irradiated, is changed. An optical path length adjusting section adjusts the optical path length of one of the measuring light beam, the reflected light beam, and the reference light beam, based on the obtained tomographic data.

Abstract: Interferometric scanning method(s) and apparatus for measuring test optics having aspherical surfaces including those with large departures from spherical. A reference wavefront is generated from a known origin along a scanning axis. A test optic is aligned on the scanning axis and selectively moved along it relative to the known origin so that the reference wavefront intersects the test optic at the apex of the aspherical surface and at one or more radial positions where the reference wavefront and the aspheric surface intersect at points of common tangency (“zones”) to generate interferograms containing phase information about the differences in optical path length between the center of the test optic and the one or more radial positions. The interferograms are imaged onto a detector to provide an electronic signal carrying the phase information.

Abstract: Methods and apparatus are disclosed for measurement of critical dimensions (CD) of features and detection of defects in reflecting UV, VUV, and EUV lithography masks and in transmitting UV and VUV lithography masks. The measured CD's may be used in the determination of optical proximity corrections (OPC) and/or in mask fabrication process control. The transmitting masks may comprise binary and various types of phase shift masks.

Abstract: Apparatus and method can be provided, whereas a particular radiation which includes at least one first electro-magnetic radiation can be directed to at least one sample and at least one second electro-magnetic radiation can be directed to a reference. The first electro-magnetic radiation having a particular cross-sectional width may be applied to at least one portion of the sample to generate at least one third electro-magnetic radiation. The first electro-magnetic radiation can be provided in the portion along a particular axis for a distance between a multiplier of 0.5 and 100 of the particular cross-sectional width. An interference can be detected between the third electro-magnetic radiation associated with the first electro-magnetic radiation and at least one fourth electro-magnetic radiation associated with the second electro-magnetic radiation. Further, an asymmetrical cross-sectional area of the first electro-magnetic radiation can be provided.

Abstract: A surface texture measuring instrument provided with a near-field measuring unit (30) including a near-field probe (33) that forms a near-field light at a tip end thereof when a laser beam is irradiated, a laser source (35) that generates the laser beam to be irradiated on the near-field probe (33), a detection element (38) that detects scattering effect of the near-field light generated when the near-field probe (33) is moved close to a workpiece (1), and an actuator (32) that displaces the near-field probe (33) and the workpiece (1) in a direction moving close to/away from each other, includes: a laser length-measuring unit (20) that measures a relative distance between a reference position and the workpiece (1) in the vicinity of the tip end of the near-field probe (33) or a relative distance between the reference position and the near-field probe (33).

Abstract: A method for measuring a thickness of a coating of a constructional unit, in particular a heat-compatible coating on a component of a gas turbine, includes measuring coordinates of the constructional unit three-dimensionally with a measuring device, in particular an optical scanner, before and after the coating, a thermal distortion of the constructional unit being recorded during the coating and the thickness of the coating being determined from a comparison of the measured constructional unit coordinates before and after the coating. The thermal distortion of the constructional unit is taken into account in the thickness determination of the coating by a comparison with at least one reference point at an uncoated location.

Abstract: Air gap variation in an interferometric modulator over a two-dimensional spatial map of the modulator is determined by acquiring a digital photograph of the modulator. Color parameters of individual pixels in the photograph are determined and compared to a model of color parameters as a function of air gap distance. The model and individual pixel color parameters may be plotted on a color space plot for comparison. The determined distances may be plotted over a two-dimensional spatial map of the interferometric modulator to visualize the mirror curvature and air gap variation.

Abstract: A method of measuring properties of a substrate, the method involving: illuminating a spot on the substrate with a standing wave measurement beam to generate a return measurement beam, the standing wave measurement beam characterized by a standing wave pattern; generating an electrical signal from the return measurement beam; causing the standing wave pattern to be at a succession of different positions on the surface of the substrate; and for each of the succession of different positions of the standing wave pattern, acquiring measurement data from the electrical signal.

Abstract: An optical system includes a photolithography system, a low coherence interferometer, and a detector. The photolithography system is configured to illuminate a portion of an object with a light pattern and has a reference surface. The low coherence interferometer has a reference optical path and a measurement optical path. Light that passes along the reference optical path reflects at least once from the reference surface and light that passes along the measurement optical path reflects at least once from the object. The detector is configured to detect a low coherence interference signal including light that has passed along the reference optical path and light that has passed along the measurement optical path. The low coherence interference signal is indicative of a spatial relationship between the reference surface and the object.

Abstract: Two common-path interferometers share a measuring cavity for measuring opposite sides of opaque test parts. Interference patterns are formed between one side of the test parts and the reference surface of a first of the two interferometers, between the other side of the test parts and the reference surface of a second of the two interferometers, and between the first and second reference surfaces. The latter measurement between the reference surfaces of the two interferometers enables the measurements of the opposite sides of the test parts to be related to each other.

Abstract: There is described a method for waking up an optical sensing device from a sleep mode to a motion detection mode, the optical motion sensing device comprising a light source, a photodetector device, a motion sensing unit and a control unit, the motion detection mode being defined as a mode during which motion is detected between the optical motion sensing device and a portion of a surface illuminated by the light source at a defined flash rate being set between minimum and maximum flash rate values, the motion sensing unit sending motion reports to the control unit, the sleep mode being defined as a mode during which the flash rate is set to a low flash rate value being lower than the minimum flash rate value and no motion report being reported from the sensing unit to the control unit, wherein the method comprises during the sleep mode the steps of (i) illuminating said surface portion with radiation by means of the light source at the low flash rate value; (ii) detecting a radiation pattern reflected from t

Abstract: An apparatus for use in rotational measurement. A rotational assembly is provided that is rotationally movable about a rotational axis. At least two interferometers are provided that are each able to receive a respective light beam, separate it into both reference and measuring beams and direct their respective measuring beam to and receive it back from the rotational assembly. The said rotational assembly includes a plurality of cube corners mounted so that at least one is able to receive from and reflect back to one of the interferometers its measuring beam as the rotational assembly rotates. The interferometers combine their reference and measuring beams into respective detection beams, wherein at least one such detection beam includes an interference signal that is process able to determine any rotational measurement of the rotational assembly and any work piece target attached to it.

Abstract: The invention relates to an interferometer arrangement (1000) having at least one measuring beam path for providing light in an object area, at least one reference beam path and at least one unit for superposing light of the measuring beam path with light of the reference beam path and a unit for detecting an interference phenomenon caused by light from the object area and light from the reference beam path. The invention further relates to a method for measuring the velocity of an object with an interferometer arrangement. In the interferometer arrangement, the unit for detecting has a spatial resolution which corresponds to the characteristic spatial period of the interference phenomenon. In evaluating the time change of the interference signal, the movement of stray centers can be measured. Use of such an interferometer arrangement in a surgical microscope allows to visualize areas of a field of surgery which cannot be accessed with light in the visible spectrum.

Abstract: The invention concerns an apparatus for parallel detection of the behaviour of mechanical micro-oscillators interacting with the sample (21). The amplitude and the phase of resonance of micro-oscillators (12) are measured with optical means. The invention is characterised in that a source (1) is active during a fraction 1/n of the period (n being an integer) and of variable phase p/n of the period (p being an integer). Interferences are produced between light beams generated by reflection of incident light beams (7) and (8) on the micro-oscillators (12). Periodically the micro-oscillators (12) are displaced by means. The value of the parameter p (p being an integer) is varied and N elementary measurements are integrated to obtain a measurement representing each of the values of p. The phase and amplitude of each micro-oscillator (12) are calculated on the basis of the representative data obtained for each value of p and this for a large number of accumulations.

Abstract: A coefficient of linear expansion measuring apparatus includes: two reflection plates between which a sample is put, a container to house them, which is filled with a gas having known rate of a refractive index variation, a temperature regulating member to set a temperature in the container variably, a light source to irradiate an irradiating light to reflecting surfaces of the reflection plates, a light receiving element to receive reflected lights in which the lights interferes each other and detecting a light intensity thereof, and a calculating member to calculate a coefficient of linear expansion of the sample, wherein: the calculating member calculates an optical path length variation between the reflecting surfaces from an output variation of the light receiving element, and calculates a length variation of the sample by correcting a part of the optical path length variation derived from the refractive index variation of the gas caused by the temperature variation.

Abstract: A data input device for use with a tracking surface having light-scattering properties with respect to the device. The device comprising a single laser having a modulated light beam. A beam splitter splits the modulated light beam into two light beams projected along separate paths toward the tracking surface. A portion of the light striking the tracking surface reflects back into a cavity of the single laser for self-mixing with the projected light, thereby altering first and second characteristics of the projected modulated light beam according to first and second directions associated with the tracking surface. A detector associated with the laser detects the altered first and second characteristics of the modulated light beam projected by the laser, and a controller responsive to the detector determines the relative movement of the tracking surface and data input device relative to one another as a function of the altered first and second characteristics detected by the detector.

Abstract: Two different phase components obtained by splitting interference light of light from an object by a diffraction grating are guided to first and second PD's by a second optical system. A first signal is outputted from a first signal processing circuit section that receives light reception signal from first PD, and a second signal is outputted from a second signal processing circuit section that receives a light reception signal from the second PD. A third signal of an interference light signal whose noise component is removed is outputted by a third signal processing circuit section using the first signal and the second signal. Then, the frequency of the third signal is detected, and the movement velocity of the object is detected by a movement velocity detection section on the basis of the frequency.

Abstract: A method of using an interferometric confocal microscope to measure features of a trench or via in a substrate, wherein the interferometric confocal microscope produces a measurement beam, the method involving: focusing the measurement beam at a selected location at or near the bottom of the trench or via to excite one or more guided-wave modes within the trench or via; measuring properties of a return measurement beam that is produced when the measurement beam is focused at the selected location, wherein the return measurement beam includes a component corresponding to a radiated field from the one or more guided-wave modes that are excited within the trench; and determining the features of the trench or via from the measured properties of the return measurement beam.

Abstract: An apparatus and method may be used for welding a first panel to a second panel, the first panel having an inboard side partially contacting the second panel and an opposite outboard side. The apparatus has a welding beam generator. The apparatus reduces a pressure along the inboard side of the panel relative to an adjacent pressure along the outboard side so as to produce inward deflection of the first panel along a first portion of the first panel not contacting the second panel relative to a second portion. The apparatus has locates, based on said deflection, at least one of said first portion or said second portion.

Abstract: Interferometric apparatus and methods for assembling and measuring highly precise optical assemblies such as triple corner cubes, and the like. The apparatus and methods use one or more interferometers that can simultaneously measure the shape, orientation, and distance to one or more surfaces.

Abstract: A system and method for obtaining metrics of a semiconductor chip are provided. A first surface of a chip is positioned on a substantially flat receiving surface. A topography of the receiving surface is measured. A topography of a second surface of the chip is also measured. A relative angle between the receiving surface and the second surface of the chip are determined using the measurements of the receiving surface and the second surface of the chip.

Abstract: A Method for measuring vibrations in small and microscopic objects is disclosed. The method includes the steps of vibrating the object at a frequency, illuminating the object with a light source which is phase modulated at the same frequency, collecting data from a detector array, operating an algorithm to calculate the size of interference modulation between the light waves, operating an algorithm based on multiple calculation of the modulation at different vibration phases between the excitation of the object on one hand, and the reference phase modulation on the other, and operating an algorithm based on use of the result from the calculation of the second modulation, calculating amplitude values and phase values for the vibration of the surface of the object.

Abstract: The invention provides a method for a method for determining a best initial focal position estimate for a current sample location on a substrate comprising multiple sample locations, comprising determining the best initial focal position estimate by using a result from one or more techniques selected from the group consisting of linear regression analysis of focal positions determined for at least two other sample locations on the substrate and quadratic regression analysis of focal positions determined for at least three other sample locations on the substrate.

Abstract: Provided is a displacement sensor which allows at least part of the data used from the time of obtaining an image until the time of computing the displacement can be readily verified. In a displacement sensor for automatically extracting a coordinate of a measuring point from an image obtained by using an imaging device according to a prescribed measuring point extraction algorithm, and computing a desired displacement from the automatically extracted measuring point coordinate, the sensor is further provided with the function to edit data used from the time of obtaining the image until the time of computing the displacement for use as display data for an image monitor.

Abstract: A displacement information detector in which a coherent luminous flux from a light source is applied to a diffraction grating scale adapted to be relatively moved to generate two diffracted rays of light having different orders, and the two diffracted rays of light are diffracted and deflected in a diffraction grating in which circular or toric curves are arranged in lattice at unequal pitches to be irradiated to the diffraction grating scale again to be rediffracted, and the diffracted rays of light are combined with each other to be made interfere each other, and the resultant interference light is introduced into a light receiving element to thereby detect a periodic signal due to the relative movement of the diffraction grating scale.

Abstract: A system for determining at least one condition of a substrate includes an optical waveguide for transmitting light from a light source. The optical waveguide can be embedded in the substrate and operatively coupled to an interferometric system. The interferometric system is operatively coupled to a processor. The interferometric system provides the processor with information relating to transmissions through the wave guide, which are indicative of substrate conditions and/or operations being performed relative to the substrate.

Abstract: While a ferrule held by a clamping apparatus is rotated by a predetermined angle, respective interference fringe images of a spherical leading end part of the ferrule are obtained at three or more rotational positions. Respective interference fringe center positions are obtained in thus obtained three or more interference fringe images. The center position of a circle passing near each of the interference fringe center positions is calculated and defined as a measured center position. Relative distance information between the measured center position and a position corresponding to the rotational center position of the spherical leading end part of the ferrule or the relative distance information and relative directional information thereof are outputted as an inclination error adjustment value for the axis of the ferrule.

Abstract: An optoelectronic component has a carrier body as well as an optoelectronic transmitter for emitting a coherent light beam and an optoelectronic receiver, which are applied on the carrier body. An optical device splits the light beam emitted by the optoelectronic transmitter into a reference beam and a measurement beam. The measurement beam reflected at the measurement object is received and superposed with the reference beam to form an interference beam. The interference beam is directed onto the optoelectronic receiver. The optoelectronic component furthermore contains a spacer, which is applied on the carrier body and on which the optical device is applied. The optical device is disposed parallel to and at a distance from the carrier body defined by the spacer.

Abstract: Embodiments of the present invention are directed to reducing cyclic error in the beam launcher of an interferometer. In one embodiment, an interferometry apparatus comprises a reference beam directed along a reference path, and a measurement beam spatially separated from the reference beam and being directed along a measurement path contacting a measurement object. The reference beam and the measurement beam have a single frequency. At least a portion of the reference beam and at least a portion of the measurement beam overlapping along a common path. One or more masks are disposed in the common path or in the reference path and the measurement path to spatially isolate the reference beam and the measurement beam from one another.

Abstract: A method and system using spectral interference of light from plasma emissions collected at near grazing incidence to in-situ monitor and control the film thickness of a non-opaque film. Embodiments of this invention are particularly useful to all substrate processing chambers equipped to form an in-situ plasma within the chamber and which are used to deposit or etch non-opaque films. One embodiment of the method of the present invention forms a plasma within a substrate processing chamber to deposit a non-opaque film on a wafer substrate within the chamber. During the plasma deposition process, a plurality of wavelengths of radiation including those reflected from the top and bottom layer of the film being deposited upon a wafer surface are collected through an existing viewport, and conveyed to a spectrometer for measurements via an optical fiber attached near this viewport. These measurements are analyzed to determine the film's thickness.

Abstract: Spatial filtering of beams in interferometry systems is used to reduce a displacement of the beams from an optical path corresponding to the path of the beams in an optimally-aligned system. By reducing beam displacement from the optical path, the system reduces the magnitude of beam shears and associated non-cyclic errors in linear and angular displacements measured by the interferometry systems.

Abstract: The present invention teaches a method and apparatus for making measurement of an object on a machine, such as a machine tool, using an optical measuring apparatus which includes a light source for generating a beam of light which is incident on a detector. A detection signal is generated within the detector each time the beam is interrupted. The duration and/or frequency of the detection signals are evaluated and an output signal is emitted from the detection only if a further detection signal is present within the detector in a specified time interval from the generation of an earlier detection signal.

Abstract: A method for optically detecting a trench depth includes detecting a first maxima in an intensity of multi-wavelength light. A portion of the multi-wavelength light is reflected from a top trench surface. A second maxima in an intensity of multi-wavelength light is also detected. A portion of the multi-wavelength light is reflected from a bottom trench surface. A maxima peak separation between the first maxima and the second maxima is determined. The trench depth corresponds to the maxima peak separation.

Abstract: The present invention is directed to a scanning system that uses uniform rotary motion of an optical reflector to create reciprocal linear scanning. The system converts uniform rotation into uniform longitudinal scanning. The system thereby creates mechanical reciprocal linear scanning free of reciprocally moving mechanical parts common in conventional scanning systems. In a preferred embodiment of the invention, the scanning system is incorporated within an imaging catheter for medical scanning. The optical reflector is rotatable and includes a spiral reflecting portion. The spiral reflecting portion may be a single uniform reflecting surface or may include several reflection surfaces arranged in a spiral configuration.

Abstract: An optical system, in particular an exposure lens for semiconductor lithography, with a plurality of optical elements has at least one load-dissipating structure. The load-dissipating structure diverts the forces originating from the optical elements. The optical system also has a measuring structure constructed independently of the at least one load-dissipating structure.

Abstract: Disclosed herein is an apparatus for measuring sub-resonance, which is capable of simultaneously measuring the fundamental frequency characteristics and displacements of an optical pickup actuator through the use of a very simple interferometer. The sub-resonance measuring apparatus of the present invention includes a laser light source, a beam splitter, and an optical detection element. The beam splitter splits light emitted from the laser light source into two light beams. The beam splitter has a reference surface that allows a part of a first beam of the two light beams to be reflected inside of the reference surface and allows the remaining part thereof to pass through the reference surface, and a diffused surface that allows a second beam of the two light beams to be dispersed thereon.

Abstract: An alignment measuring system includes a focusing diode, a light source, an image sensor, first and second splitters, a focusing diode, and a controller. The first splitter directs a portion of light from the light source toward a wafer, and directs light returned by the wafer to the second splitter. The second splitter directs a first portion of the light toward the image sensor, and a second portion of the light toward the focusing diode, and control the ratio of the first and second portions in response to a control signal from the controller. The image sensor receives the first portion of light and produces a detection signal. The controller receives the detection signal, determines an alignment state of the wafer, and controls a stage to align and position the wafer.

Abstract: The invention features a method for determining a geometric property of a test object, the method including: interferometrically profiling a first surface of the test object in a first coordinate system; interferometrically profiling a second surface of the test object in a second coordinate system different from the first coordinate system; providing a relationship between the first and second coordinate system; and calculating the geometric property based on the interferometrically profiled surfaces and the relationship between the first and second coordinate system. In some embodiments, the relationship may be determined by using calibrated gage blocks or by using a displacement measuring interferometer. Corresponding system are also described.

Abstract: A system for inspecting a component is provided. The system includes an interferometer having a coated mirror, such as a coating that allows only a fraction of light to pass, where the coating has a predetermined thickness. An interference inspection system receives reflected light from the component through the interferometer and determines whether interference is occurring at each of two or more predetermined areas, such as at point corresponding to a bump contact and at a second point corresponding to a substrate. The thickness of the coating is related to a height difference between two or more of the predetermined areas, such as by creating interference at both areas by changing the reflection path length by an amount required to cause simultaneous interference fringing for a designed height difference.

Abstract: A test reticle having a pad and antenna structures with varying critical dimensions is provided to measure sidewall angles developing in the resist sidewalls of clear lines. These sidewall angles originate from resist flow due to the occurrence of excessively high temperatures in a resist process on a lithographic track after the exposure of a semiconductor wafer. A scanning electron microscope is used to perform the measurement. A sequence of temperatures is applied in each postbake step to process a wafer, and the sidewall angle is determined afterwards from e.g. a critical dimension measurement with a known resist thickness. An error signal is issued, if a threshold value of a sidewall angle is exceeded. The temperature of the resist process, e.g. the postbake, is then adjusted to a temperature below the temperature causing the warning signal.

Abstract: Aspects of the present invention provide novel methods and devices for sampling gas, exciting the sampled gas to emit radiation and detecting in real time from the emitted radiation a plurality of wave bands of an emission spectrum. Energy used to excite the sampled gas may be adjusted based on the detected wave bands. A process may be controlled in real time based on the detected wave bands. Novel interfaces may be used to display portions of the detected wave bands. A known flow of a reference gas may be included in the flow of sampled gases and an unknown flow of an unknown flow gas determined.

Abstract: The present invention is directed to a fiber optic media thickness sensor used in a print media or document processing device. The invention is further directed to a method for measuring media thickness in a media processing device using a fiber optic sensor.

Abstract: A length measuring apparatus is provided that combines upper data with lower data and then outputs the composite data. The apparatus monitors taking down or up a digit of upper data or lower data and synchronization of lower data, thus preventing an occurrence of reading error. When an A/D area showing an area of lower data matches with an upper area quadrant showing an area of upper data (R2, R3), the upper count value outputting the upper data is output without any change. When the quadrant (0, 1, 2, 3) of the A/D area does not match with the quadrant (0, 1, 2, 3) of upper area because of an erroneous timing of a digit-taking-up of upper data (R1, R4), +1 or −1 is added to the upper count value. Thus, the continuity of a measured value can be obtained when the scale is being moved.

Abstract: A measurement device for oscillation measurement, as well as a corresponding method, is proposed, wherein the oscillation measurement is performed by at least one laser interferometer (2, 3), whose measurement beam is directed onto various measurement points (5) of the object (1) for generating a scanning movement, and the obtained oscillation data is correlated with the position data of the respective measurement point (5) and evaluated or displayed. In particular, for three-dimensional measurements, the invention reduces the measurement complexity because the scanning device is a robot arm, which moves a measurement head of the laser interferometer to the desired measurement points on the object.

Abstract: A system and method for non-linearity compensating interferometer position data includes receiving a plurality of groups of digital position values. A first group of the digital position values are digitally processed to generate a plurality of data values. The plurality of data values are digitally processed to generate at least one quasi-static non-linearity parameter. A second group of the digital position values are compensated based on the at least one non-linearity parameter.