Abstract: A system and method for dispersion-force-based actuation are disclosed. In some embodiments, a light beam is used to change the dispersion force between two spaced apart surfaces. The change in the dispersion force causes a change in the gap between the surfaces. The actuation system can be used in conjunction with a deformable mirror to provide an improved adaptive optics system.

Abstract: The present invention relates to a vibration-insensitive interferometer using a high-speed camera and a continuous phase scanning method. The interferometer measures a measurement target by completely isolating influences of externally occurring vibrations from a frequency domain. The interferometer includes a light source unit for emitting light. A light transmission unit radiates the light emitted from the light source unit to the measurement target, splits light reflected from the measurement target into reference light and measurement light, and allows the reference light and the measurement light to interfere with each other, thus generating an interference fringe. A continuous phase scanning unit for radiates the reference light split by the light transmission unit through continuous phase scanning.

Abstract: A holographic data storage system that includes a write head that includes a pixellated spatial light modulator and a separate or integral phase mask that varies the phase depending on the location in the phase mask that light passes through. The phase variation can be changed over time in a random, pseudo-random, or predetermined fashion. The spatial light modulator and phase mask can be implemented in a liquid crystal SLM (nematic, ferroeleletric, or other), in a DMD SLM, in a magneto-optical SLM, or in any other suitable manner.

Abstract: A method includes comparing a scanning interferometry signal obtained for a location of a test object to each of multiple model signals corresponding to different model parameters for modeling the test object, wherein for each model signal the comparing includes calculating a correlation function between the scanning interferometry signal and the model signal to identify a surface-height offset between the scanning interferometry signal and the model signal and, based on the identified surface-height offset, calculating a height-offset compensated merit value indicative of a similarity between the scanning interferometry signal and the model signal for a common surface height. The method further includes, based on the respective merit values for the different model signals, determining a test object parameter at the location of the test object.

Abstract: An observation device 1 comprises a light source unit 10, a biaxial scanning system 20, a wavefront modulation unit 30, an optical branching unit 40, a light detection unit 50, a wavefront detection unit 60, a control unit 70, and the like. The wavefront modulation unit 30 presents a compensating phase pattern for compensating for an aberration of input light and a branching phase pattern for splitting the input light into first and second beams. The wavefront detection unit 60 receives inputted light and detects a wavefront of the inputted light. The compensating phase pattern for compensating for the wavefront aberration is feedback-controlled in loop processing that includes the detection of a wavefront distortion of the light by the wavefront detection unit 60, the adjustment of the phase pattern by the control unit 70 according to the result of detection, and the presentation of the phase pattern by the wavefront modulation unit 30.

Abstract: A label-free interferometric biosensor is disclosed which is based on the self-mixing optical interferometer. Inside the biosensor, an incoming beam is divided into two beam portions which pass through a channel and bio materials, respectively. Interference of the portions is realized by the self-mixing effect and used to detect existence of an analyte, such as DNA or protein molecules. The label-free biosensor is compact and can be made on a chip using the semiconductor technology. It is also convenient to use due to moderate alignment requirement. Furthermore, an array of the interferometers fabricated on a chip enables high-throughput and highly parallel measurements.

Abstract: A system and method forming near diffraction limited size beacon for adaptive optical system using a temporally partially coherent laser source. Comprises projection of laser beams through turbulent medium having non-cooperative target using combination of adaptive optical system and short temporal coherence length laser source forming controllable focused laser target beacon. Combines adaptive optical system technology using any wavefront sensing technique making complex field measurements with short coherence length and associated broad spectral bandwidth. The partially coherent laser source forms narrow (near diffraction limited) size region of coherent laser light at target. The coherent region of return dominates signal for any measurement technique computing average of field over wavelength bandpass and can be used to pre-compensate either the partially coherent laser beam, a long coherence length beam of different wavelength or wavelength in bandpass, or both.

Abstract: Systems and methods are provided for multi-function coherent imaging comprising directing a first coherent radiation beam and a second coherent radiation beam towards a detector, where the second coherent radiation beam is spatially offset, angularly offset, or spatially and angularly offset from the first coherent radiation beam. A portion of the first coherent radiation beam and a portion of the second coherent radiation beam may be combined to form a composite beam. An object may be radiated with the composite beam. A first intensity pattern may be formed by interfering with return radiation from the radiated object with the first coherent radiation beam and a second intensity pattern is formed with the return radiation from the radiated object and the second coherent radiation beam. A detector may simultaneously record a superposition of the first intensity pattern and the second intensity pattern.

Abstract: According to various embodiments, provided herein is an optical system and method that can be configured to perform image analysis. The optical system can comprise a telescope assembly and one or more hybrid instruments. The one or more hybrid instruments can be configured to receive image data from the telescope assembly and perform a fine guidance operation and a wavefront sensing operation, simultaneously, on the image data received from the telescope assembly.

Abstract: A wavefront is measured with superior precision even if the density of scatterers in the vicinity of a focal plane is low. Provided is a wavefront measurement method including a contrast measuring step of measuring the contrast of an interference pattern corresponding to each part of a specimen containing a scatterer, generated by interfering reference light and return light from a focal plane in the specimen; a region extracting step of extracting a high-contrast region in which the contrast measured in the contrast measuring step is greater than or equal to a prescribed threshold; and a wavefront calculating step of converting an interference pattern corresponding to the high-contrast region to wavefront data, for the high-contrast region extracted in the region extracting step.

Abstract: An adaptive optics system comprises a spatial light modulator, a beamsplitter, a pixelated spatial phase shifter, a beam combiner, an imaging device, and a processor. The spatial light modulator can modulate an incoming beam with an aberrated wavefront. The beamsplitter can receive the modulated beam and divide the modulated beam into a first beam and a second beam. The pixelated spatial phase shifter can spatially phase shift the second beam by at least two phases. The beam combiner can interfere the spatially phase shifted second beam with the first beam to form at least two interferograms on the imaging device, which can capture an image of the at least two interferograms in a single frame. The processor can determine the aberrated wavefront based on the at least two interferograms and provide one or more control signals to the spatial light modulator to mitigate aberrations in the aberrated wavefront.

Abstract: Disclosed herein is an interferometry device and associated method and computerized media for testing optical components including those with high aberrations, comprising: situating an optical component under test between a source of a spherical test wavefront and a reference mirror; propagating a spherical test wavefront, whereby an axial line is defined by a direction of propagation of said wavefront; deriving a substantially complete first-tilt-alignment wavefront metrology of the optical component under test from a plurality of first-tilt-alignment interferograms obtained with the optical component under test held fixed at a first predetermined tilt angle relative to a direction of propagation of said wavefront; and varying an axial displacement between the optical component under test and the spherical reference mirror to obtain each first-tilt-alignment interferogram. By varying the tilt angle, one can also derive a substantially complete surface metrology of the optical component under test.

Abstract: Apparatus, techniques and systems for implementing an optical interferometer to measure surfaces, including mapping of instantaneous curvature or in-plane and out-of-plane displacement field gradients of a sample surface based on obtaining and processing four optical interferograms from a common optical reflected beam from the sample surface that are relatively separated in phase by ?/2.

Abstract: A method of aligning at least two wave shaping elements, a method of measuring a deviation of an optical surface from a target shape and a measuring apparatus for interferometrically measuring a deviation of an optical surface from a target shape.

Abstract: A Fizeau interferometer includes: a reference spherical surface; and a measuring apparatus including an intensity obtaining section and a form calculating section, wherein: a focal point of the reference spherical surface is aligned with a center of curvature of the spherical surface in order to set the center of curvature as a center position, and two positions equidistant from the center position are set as a start position and an end position, the intensity obtaining section obtains the intensity maps of the interferograms at n positions at equal intervals; and the form calculating section measures the form of the spherical surface using a phase analysis method in which a coefficient of the intensity maps of the interferograms at an i-th position and a coefficient of the intensity maps of the interferograms at an (n?i+1)th position have a same value.

Abstract: Methods and devices are disclosed for acquiring depth resolved aberration information using principles of low coherence interferometry and perform coherence gated wavefront sensing (CG-WFS). The wavefront aberrations is collected using spectral domain low coherence interferometry (SD-LCI) or time domain low coherence interferometry (TD-LCI) principles. When using SD-LCI, chromatic aberrations can also be evaluated. Methods and devices are disclosed in using a wavefront corrector to compensate for the aberration information provided by CG-WFS, in a combined imaging system, that can use one or more channels from the class of (i) optical coherence tomography (OCT), (ii) scanning laser ophthalmoscopy, (iii) microscopy, such as confocal or phase microscopy, (iv) multiphoton microscopy, such as harmonic generation and multiphoton absorption.

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

Abstract: In certain aspects, disclosed methods include combining reference light reflected from a reference surface with test light reflected from a test surface to form combined light, the test and reference light being derived from a common source, sinusoidally varying a phase between the test light and reference light, where the sinusoidal phase variation has an amplitude u, recording at least one interference signal related to changes in an intensity of the combined light in response to the sinusoidal variation of the phase, determining information related to the phase using a phase shifting algorithm that has a sensitivity that varies as a function of the sinusoidal phase shift amplitude, where the sensitivity of the algorithm at 2 u is 10% or less of the sensitivity of the algorithm at u.

Abstract: System and method for estimating and correcting an aberration of an optical system. The method includes capturing a first plurality of images on a first plurality of planes. The first plurality of images is formed by at least the optical system. Additionally, the method includes processing at least information associated with the first plurality of images, and determining a first auxiliary function based upon at least the information associated with the first plurality of images. The first auxiliary function represents a first aberration of the optical system. Moreover, the method includes adjusting the optical system based upon at least information associated with the first auxiliary function.

Abstract: A method for investigating and ascertaining pulse or heartbeat includes directing illuminating radiation to illuminate a body part such as a finger. The illuminating radiation is of a wavelength or wavelength band substantially in the blue light region of the light spectrum. Then, an optical speckle pattern of the illuminated body part resulting from the illumination of the body part is obtained and imaged. The optical speckle pattern is representative of the heartbeat and by correlation of frames extracted from the speckle pattern, the pulse or beat extent of the body part may be ascertained.

Abstract: An apparatus for measuring a shape of a surface, comprises a measurement head which measures at least one of a distance between a reference point and the surface and a direction of a normal from the surface to the reference point, a scanning mechanism which scans the measurement head, and a processor which calculates the shape of the surface based on a measurement result measured using the measurement head and coordinates of the reference point, wherein the coordinates of the reference point are calibrated using a measurement result measured by scanning the measurement head along a scanning path in association with a first surface to be measured, and a shape of a second surface to be measured is calculated based on a measurement result measured by scanning the measurement head along the same scanning path in association with the second surface, and the calibrated coordinates of the reference point.

Abstract: Disclosed herein are methods and apparatus for testing interferometric modulators. The interferometric modulators may be tested by applying a time-varying voltage stimulus and measuring the resulting reflectivity from the modulators.

Abstract: A grazing incidence interferometer includes: a beam splitting section configured to split a beam from a beam source section into a measuring beam emergent to a measurement surface and a reference beam serving as a measurement reference, and configured to cause the measuring beam to emerge obliquely to the measurement surface; a beam combining part configured to combine the reference beam and the measuring beam reflected at the measurement surface, to obtain a combined beam; a detecting section configured to detect a profile of the measurement surface based on an interference fringe formed by the combined beam; and an image inverting part configured to invert an orientation of a wave front of the measuring beam or the reference beam, the image inverting part being provided in an optical path of the measuring beam or the reference beam leading from the beam splitting section to the beam combining section.

Abstract: Disclosed herein is an apparatus for measuring the shape of a 3D object using an interferometer. The apparatus includes a light source unit, a beam splitter, a reference mirror, an actuator, an image pickup device, and a control unit. The light source unit emits light. The beam splitter divides the light from the light source unit. The reference mirror reflects light as a reference beam. The actuator moves the reference mirror. The image pickup device acquires a plurality of interference patterns by causing the reflected beam and the reference beam to interfere with each other. The control unit measures the shape of the object from the acquired interference patterns, outputs reference mirror drive signals to the actuator, and issues an image capture command at the end of image capture time that is shorter than settling time.

Abstract: A system with two unequal path interferometers, with a first flat, a second flat, and a cavity between the first and second flats, a holder to receive an object in the cavity such that an optical path remains open between the first and second flats, and a motor coupled to the holder such that the object may be tilted in the cavity to allow for measurements of, and a radiation assembly to direct collimated radiation to the interferometer assembly, a collecting assembly to collect radiation received from the interferometer assembly, and a controller comprising logic to; vary a wavelength of the radiation, record interferograms, extract phases of the interferograms to produce phase maps, determine from each map areas with high slopes, tilt the holder to allow measurement of the high slope areas, and process measurement that covers the entire surface of the object.

Abstract: A measurement method for measuring a shape of a target using an interference pattern includes the steps of converting a first interference pattern into a first shape of the target (S103 to S105), obtaining a second interference pattern at a position where the target moves in an optical axis direction of the reference surface (S107, S108), unwrapping the second interference pattern after aligning a phase of the first interference pattern with a phase of the second interference pattern (S109), converting the unwrapped second interference pattern into a second shape of the target (S110), determining whether or not the first shape of the target coincides with the second shape (S111), and calculating the shape of the target by adding the integral multiple of a wavelength of the light source to the unwrapped second interference pattern if the first shape does not coincide with the second shape (S112).

Abstract: Systems and methods for facilitating focusing of an image scanner, such as a confocal microscope, are disclosed. Measurement of optical characteristics in certain areas of a test sample are compared to stored or baseline optical characteristic profiles to determine an appropriate correction to properly focus the scanner. In one aspect, the method includes obtaining a dynamic profile at a current detection region of a test sample and associating the dynamic profile to a profile selected from a set of stored baseline profiles. Each of the stored baseline profiles is associated with a correction.

Abstract: In certain aspects, disclosed methods include combining reference light reflected from a reference surface with test light reflected from a test surface to form combined light, the test and reference light being derived from a common source, sinusoidally varying a phase between the test light and reference light, where the sinusoidal phase variation has an amplitude u, recording at least one interference signal related to changes in an intensity of the combined light in response to the sinusoidal variation of the phase, determining information related to the phase using a phase shifting algorithm that has a sensitivity that varies as a function of the sinusoidal phase shift amplitude, where the sensitivity of the algorithm at 2 u is 10% or less of the sensitivity of the algorithm at u.

Abstract: Electromagnetic illumination radiation is produced and provided as an input wave. The input wave passes through a diffractive optical element and leaves as an incoming measuring wave, the wave front of the input wave being transformed such that the wave front of the incoming measuring wave is adapted to the desired shape of the effective reflection surface. Furthermore, the test object is disposed in a test position in which the incoming measuring wave is reflected back to the diffractive optical element as a reflected measuring wave, the reflected measuring wave passing through the diffractive optical element and leaving as an outgoing measuring wave, the propagation direction of the outgoing measuring wave being deviated in relation to the opposite propagation direction of the input wave. A reference wave branched off from the illumination radiation interferes with the outgoing measuring wave this interference being recorded by detector.

Abstract: A segmented array, perfectly aligned except for piston wraps, will have perfect imaging at wavelength ? but will have degraded imaging at other wavelengths. The present method detects and corrects piston wraps by making image-based measurements at a wavelength ? and a second wavelength ?1. These measurements will produce an image of the piston-wrapped segments and the intensities of these segments in the image at wavelength ?1 are linearly related to the sizes of the piston wraps at wavelength ?. The method needs no additional equipment like inter-segment apertures, lenslets, and detectors. It needs only a narrowband filter to change the measurement wavelength from ? to ?1.

Abstract: An interferometer system and method may be used to measure substrate thickness or shape. The system may include two spaced apart reference flats having that form an optical cavity between two parallel reference surfaces. A substrate holder may be configured to place the substrate in the cavity with first and second substrate surfaces substantially parallel with corresponding first and second reference surfaces such that a space between the first or second substrate surface is three millimeters or less from a corresponding one of the reference surfaces or a damping surface. Interferometer devices may be located on diametrically opposite sides of the cavity and optically coupled thereto. The interferometers can map variations in spacing between the substrate surfaces and the reference surfaces, respectively, through interference of light optically coupled to and from to the cavity via the interferometer devices.

Abstract: A method for measuring the optical properties of multifocal ophthalmic lenses. Collimated light is passed through an ophthalmic lens and onto an array of lenslets. Light exiting the array of lenslets is detected by a sensor. Blurred spots and/or double spots may represent diffractive zones of the wavefront. A centroid of the spot or a brighter of two spots may be used to determine the lateral position of the spot. Theoretical calculations, laboratory measurements, clinical measurements and experimental image spots may be generated, compared and cross-checked to determine a monofocal equivalent lens. A Modulation Transfer Function (MTF) may be used to evaluate and compare a diffractive lens and a monofocal equivalent lens.

Abstract: A noncontact form measuring apparatus emits a laser beam L. In the apparatus, a prism bends the laser beam into an X-axis direction, so that a Z-axis displacement of an objective optical system is converted by the prism into an X-axis displacement on a measurement coordinate system. A movement of an X-axis stage is converted into a Z-axis displacement on the measurement coordinate system. The apparatus moves an internal gear as a measurement object and the prism, reads X, Y, and Z coordinates at each focal point, and measures a three-dimensional form of inner teeth of the internal gear. The apparatus may translate the internal gear in a Y-axis direction, to measure a partial form of the inner teeth. The apparatus may turn the internal gear in an angular ?-direction, to measure a whole circumferential form of the inner teeth.

Abstract: An apparatus includes an evaluating unit and a peak detection unit. The peak detection unit is configured to determine at least one peak parameter of a peak in a Fourier transformed reflection spectrum of infrared radiation reflected off a sample that may comprise trench structures. The evaluation unit is configured to determine from the at least one peak parameter and from a correction value containing information about an effective refractive index of the sample, a trench parameter of the trench structures.

Abstract: Optical element having an optical surface, which optical surface is adapted to a non-spherical target shape, such that a long wave variation of the actual shape of the optical surface with respect to the target shape is limited to a maximum value of 0.2 nm, wherein the long wave variation includes only oscillations having a spatial wavelength equal to or larger than a minimum spatial wavelength of 10 mm.

Abstract: A method of aligning at least two wave shaping elements, a method of measuring a deviation of an optical surface from a target shape and a measuring apparatus for interferometrically measuring a deviation of an optical surface from a target shape.

Abstract: The present invention provides a measurement apparatus that illuminates a surface to be tested having an aspheric surface using light beams that form spherical waves to measure a figure of the surface to be tested, including a detection unit configured to detect interference patterns between light beams from the surface to be tested and light beams from a reference surface, and a controller configured to control processing for obtaining a figure of the surface to be tested based on the interference patterns detected by the detection unit.

Abstract: An apparatus including: an interferometric objective comprising a beam splitter surface configured to separate input light into test light and reference light, and a reference surface configured to receive the reference light and direct it back to the beam splitter surface, which is configured to recombine the reference light with test light reflected from a test surface, the interferometric objective further comprising one or more optical elements positioned in the path of the input light and having positive or negative optical power, wherein the reference surface is curved and defines a window to pass the input light towards the beam splitter surface.

Abstract: The invention relates to a method for interferometrically measuring large optics. A combination of a method known as stitching technique, during which the sub-interferograms are determined on partial surfaces of measuring area and are joined in a software-controlled manner and which, as a result, enables the use of small, more cost-effective interferometers, however polished surfaces of the test piece being assumed, together with an immersion method, during which, in fact, lower demands for the surface quality of the test piece exist that, however, is accompanied by edge faults. In order to make this combination possible, a modification of the stitching technique is developed, during which the measuring area (CA) is completely covered by a film consisting of an immersion liquid.

Abstract: In a wavefront sensor, an optical wavefront to be measured is split into a first optical path and a second optical path. A wavefront W1 in the first optical path is transmitted through a first compensation member 7, and a wavefront W2 in the second optical path is transmitted through a second compensation member 8. Wavefronts W1 and W2 are mixed together by a semi-transparent mirror 6 with the wavefronts being displaced from each other by a shearing quantity S to form an interference fringe. An optical path difference that occurs between two wavefronts W1? and W2? which reach the interference measurement plane M in a state where the wavefronts are inclined due to the arrival direction of the optical wavefront to be measured is compensated when the wavefronts W1? and W2? are transmitted through the first and second optical path difference compensation members 7 and 8, respectively.

Abstract: According to one aspect, a part has two reflective surfaces, one being a conic surface portion having an axis with a focus thereon, and the other being part of a spherical surface with a centerpoint at the focus. According to a different aspect, a method includes fabricating a part with first and second reflective surfaces, the first being a conic surface portion with an axis and a focus on the axis, and the second being a spherical surface portion with a centerpoint at the focus. The second surface is used to position the part so that the focus coincides with the centerpoint of a spherical wave from an interferometer. Then, a reflective further spherical surface portion on a member is used with the interferometer to position a centerpoint of the further surface at the focus. The interferometer then evaluates the first surface for accuracy.

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: A method of making a layered component with an improved surface finish by a shape metal deposition process is provided. The method comprises the steps of discriminating a first set of vectors on an exterior portion of the component from a second set of vectors on an interior portion of the component, and depositing a layer of metal material based on the vectors discriminated at different rates, wherein the material is deposited on the exterior portion at a high resolution and a slow rate, and the material is deposited on the interior portion at a low resolution and a fast rate.

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

Abstract: A method for sensing a wave-front of specimen light scattered from an illuminated area in a specimen (10) includes the steps of focusing illumination light into the specimen (10), directing specimen light scattered in the specimen (10) to a detector device (50) having a plurality of detector elements (51) and being capable to sense light with local resolution, detecting sample light contained in the specimen light with the detector device (50), said sample light being scattered in a predetermined sample plane (11) of the specimen (10) and being selected by a time-based gating of the specimen light, locally resolved measuring phase information of the sample light, and reconstructing the wave-front of the sample light on the basis of the phase information. Furthermore, a method of microscopic imaging with adapted illumination light is described.

Abstract: An oblique incidence interferometer enlarges a measurement range without increasing a size of the apparatus. The oblique incidence interferometer includes a light source for emitting coherent light in an oblique direction to a measurement object; a light collimating unit for collimating the coherent light from the light source; a beam dividing unit for dividing the collimated beam from the light collimating unit into a measurement beam and a reference beam; a beam combining unit for combining the measurement beam reflected by the measurement object with the reference beam; and an image pickup device for picking up images of interference fringes representing a surface shape of the measurement object. The oblique incidence interferometer also includes a measurement range expanding device for enlarging a light measurement range on the measurement object in a lateral direction of the measurement range.

Abstract: The present invention relates to an adaptive optics sensor intended for simultaneous detection of several wavefronts on a common camera target. The sensor is intended for use in connection with multi-conjugate adaptive optics (MCAO), where several wavefront measurements are needed at the same time. The sensor includes a spatial filter taking out signals resulting from parasitic reflections of the reference sources and from unwanted parts of the object.

Abstract: In general, in one aspect, the disclosure features a method that includes directing measurement light to reflect from a measurement surface and combining the reflected measurement light with reference light, where the measurement light and reference light are derived from a common source, and there is a non-zero optical path length difference between the measurement light and reference light that is greater than a coherence length of the measurement light. The method further includes spectrally dispersing the combined light onto a multi-element detector to detect a spatially-varying intensity pattern, determining spatial information about the measurement surface based on the spatially-varying intensity pattern, and outputting the spatial information.

Abstract: A measurement method of the present invention is a measurement method for measuring a shape of a target T from an interference pattern generated by interference between a reflected light of the target and a reference spherical surface. The measurement method includes a first measurement step which positions the target T in a first region 30a at a light source side with respect to a focal position 20 of the reference spherical surface to measure the interference pattern, and a second measurement step which positions the target T in a second region 30b opposite to the first region with respect to the focal position 20 of the reference spherical surface to measure the interference pattern.

Abstract: An optical coherence tomography device includes: a light source 1; a light splitting section 2a that splits light-source light emitted from the light source 1 into reference light and measurement light; an interfering section 2a that allows backscattered light of the measurement light backscattered by a measurement object T to interfere with the reference light reflected from a reference mirror so as to generate interference light; a photodetecting section 4 that measures the interference light; an oscillator 91 that modulates the backscattered light and the interference light by applying an ultrasonic wave, a sonic wave or an oscillation to the measurement object T; a demodulating section 53 that demodulates the interference light measured at the photodetecting section 4; and an analyzing section 52 that generates property data showing the optical backscattering property of the measurement object T on the basis of the demodulated interference light and generates image data of the measurement object T.