Abstract: Some embodiments are directed to a dermoscope and a method for forming an image of a part of a skin having one or more at least partly transparent structures, such as at least partly transparent hair. The dermoscope has a light source, a light shaping unit, and an image forming lens. The light source is arranged to provide light to the light shaping unit. The light shaping unit is arranged to direct at least part of the light via an immersion fluid to the part of the skin having the one or more at least partly transparent structures to be imaged at incident angles in the immersion fluid larger than 70 degrees relative to the optical axis of the dermoscope. The image forming lens is arranged to receive at least light refracted from the one or more at least partly transparent structures.

Abstract: The present disclosure provides a structured light projection module comprising: a Vertical-Cavity Surface-Emitting Laser (VCSEL) array light source that includes a semiconductor substrate and at least two VCSEL sub-arrays arranged thereon. The at least two VCSEL sub-arrays include VCSEL light sources. The structured light projection module further includes a diffractive optical element (DOE) that includes at least two DOE sub-units. The DOE sub-units are respectively corresponding to the VCSEL sub-arrays and configured to project multiple copies of light beams emitted by the corresponding at least two VCSEL sub-arrays.

Abstract: System and methods are provided for characterizing an internal surface of a lens using interferometry measurements. Sphere-fitting a distorted radius determines distorted pathlengths. Ray-tracing simulates refraction at all upstream surfaces to determine a cumulative path length. A residual pathlength is scaled by the group-index and rays are propagated based on the phase-index. After aspheric surface fitting, a corrected radius is determined. To estimate a glass type for the lens, a thickness between focal planes of the lens surfaces is determined using RCM measurements. Then, for both surfaces, the surface is positioned into focus, interferometer path length matching is performed, a reference arm is translated to stationary phase point positions for three wavelengths to determine three per-color optical thicknesses, and ray-tracing is performed. A glass type is identified by minimizing an error function based on optical parameters of the lens and parameters determined from known glass types from a database.

Abstract: A dynamic focusing system (DFS) for an optical device for observing an object. The dynamic focusing system (DFS) has an objective housing (OBH) including a circumferential housing part (CIH) and a light-transmitting window (LTW); a chamber (ICH) filled with an immersion medium having a refractive index substantially equal to the refractive index of the object to be observed; a movable immersed objective (MIO) configured to move along at least one direction so as to vary the focusing depth and being at least partially immersed in the immersion medium. The immersion medium is confined in the chamber (ICH) by a deformable sealing member (DSM) attached to the movable immersed objective (MIO) and to the objective housing (OBH). The deformable sealing member (DSM) is configured to ensure that the volume of the chamber (ICH) remains substantially constant upon displacement of the movable immersed objective (MIO) relative to the objective housing (OBH).

Abstract: Single-shot, adaptive metrology of rotationally variant optical surfaces, such as toroids, off-axis conies and freeform surfaces. An adaptive interferometric null test uses a high definition liquid crystal phase-only spatial light modulator (SLM) as the reconfigurable null element, on which a simulated nulling phase function is encoded, based on the specifications of the surface under test to generate a null interferogram. The power component of the surface sag is nulled by system design, not the SLM, enabling the SLM to fully compensate the residual departure without the need to tilt the optic or use a custom Offner-null. By wrapping the phase function at multiples of 2*pi radian, the upper limit in sag of the optic under test is theoretically removed.

Abstract: The present invention provides a multi-degree-of-freedom error measurement system for rotary axes and the method thereof. By producing a first ray, a second ray, and a third ray, the multi-facet reflector and the axicon disposed on an axis average line can receive the first, the second, and the third rays, respectively, for producing a reflective ray, a refractive ray, a first emitted ray, and a second emitted ray. Thereby, errors of the axicon in a plurality of degrees of freedom caused by shift or vibration of the axis average line, such as the x-axis radial error, the y-axis radial error, the axial error, the x-axis tilt error, the tilt error for the y-axis, and the angular alignment error for rotation can be measured.

Abstract: A wafer holding device (200, 415) is configured to hold a wafer (205, 416) during operation of a microlithographic projection exposure apparatus and includes at least one sensor that is positionable in different rotational positions.

Abstract: An illustrative example detection device includes a source of radiation, at least one mirror that reflects radiation from the source along a field of view having a first width, at least one optic component that is configured to refract radiation reflected from the at least one mirror, and at least one actuator that selectively moves the optic component between a first position and a second position. In the first position the optic component is outside of the field of view and does not refract any of the radiation reflected from the at least one mirror. In the second position the optic component is in the field of view and refracts at least some of the radiation reflected from the at least one mirror. The field of view has a second, larger width when the at least one optic component is in the second position.

Abstract: An apparatus and system for determining a movement of a mobile platform and methods for making and using same are provided. The method includes obtaining an error contribution value for a measurement of the movement of the mobile platform and estimate an error of the measurement based upon the obtained error contribution value.

Abstract: Synthetic quartz glass substrates are prepared by furnishing a synthetic quartz glass block, coating two opposed surfaces of the glass block with a liquid having a transmittance of at least 99.0%/mm at a birefringence measuring wavelength, measuring a birefringence of the glass block by directing light thereacross, determining a slice thickness on the basis of the birefringence measurement and the dimensions of the substrate, and slicing the glass block at the determined slice thickness.

Abstract: Microlithographic projection exposure apparatus (100) has a projection lens (150) configured to image an object plane (155) onto an image plane (156), wherein an immersion liquid is at least temporarily provided during operation of the projection exposure apparatus between the projection lens and the image plane, wherein a measurement structure (121) is arranged in the immersion liquid, and wherein the measurement structure is configured to generate a measurement pattern. The projection exposure apparatus also has a measurement device (130, 160) configured to measure the measurement pattern. The measurement structure has an absorption layer (125) including silicon oxide and/or silicon oxynitride and/or nitride.

Abstract: An embodiment of a method and system for inspecting clear and printed contact lenses is provided. A contact lens is inspected by illuminating the contact lens using bright-field illumination and low-angle dark-field illumination simultaneously, when the contact lens is disposed in a cavity between a male mold and a female mold. Further, the light emerging from the contact lens is received by an imaging optical system, and a camera uses the light received by the imaging optical system to capture an image of the contact lens. Further, a data processing system is configured to identify dark defects in the image that are in a first portion of a dynamic range of brightness, and to identify bright defects in the image that are in a second portion of the dynamic range of brightness.

Abstract: A point diffraction interferometric wavefront aberration measuring device comprising an optical source, an optical splitter, a first light intensity and polarization regulator, a phase shifter, a second light intensity and polarization regulator, an ideal wavefront generator, an object precision adjusting stage, a measured optical system, an image wavefront detection unit, an image precision adjusting stage, and a data processing unit. The center distance between the first output port and the second output port of the ideal wavefront generator is smaller than the diameter of the isoplanatic region of the measured optical system and is greater than the ratio of the diameter of the image point dispersion speckle of the measured optical system over the amplification factor thereof. A method for detecting wavefront aberration of the optical system is also provided by using the device.

Abstract: A multi field point aberration parallel detection device for a lithographic projection lens and a detection method therefor, having a spatial light modulator that is respectively arranged on the object plane and the image plane of the projection lens under test, wherein the object plane spatial light modulator and the image plane spatial light modulator are respectively disposed as an object plane grating set comprising multiple one-dimensional gratings and an image plane grating set comprising multiple two-dimensional gratings via computer programming. The gratings in the object plane grating set and the image plane grating set are conjugate one to another in respect of the projection lens under test, with each pair of conjugate grating being measured for the wave aberration of a field point.

Abstract: A device for measuring point diffraction interferometric wavefront aberration having an optical source, an optical splitter, a first light intensity and polarization regulator, a phase shifter, a second light intensity and polarization regulator, an ideal wavefront generator, an object precision adjusting stage, a measured optical system, an image wavefront detection unit, an image precision adjusting stage, and a data processing unit. A method for detecting wavefront aberration of the optical system by using the device is also disclosed.

Abstract: An method for producing an optical assembly includes a first assembling step of assembling lenses from a first lens to an (n?1)-th lens (where n is an integer of 1<n?N) to a lens-holding member to assemble a pre-assembly; an optical property-measuring step of measuring optical properties of a first optical system in the pre-assembly; an optical parameter correction value-calculating step of obtaining displacement amounts from design values of the optical properties of the first optical system based on measurement results of the optical properties, and changing the optical parameters of at least the n-th lens itself from design values thereof, thereby calculating correction values of the optical parameters of the n-th lens; a lens-producing step of producing the n-th lens based on the correction values; and a second assembling step of assembling the n-th lens produced in the lens-producing step to the pre-assembly.

Abstract: A phase distribution measurement method inside a biological sample includes taking in an optical image of the sample formed by a microscope to form a plurality of images with different image contrasts; calculating a component corresponding to phase distribution of the sample and a component corresponding to other than the phase distribution, and dividing the component corresponding to the phase distribution by the component corresponding to other than the phase distribution to forma normalized phase component image; breaking down the phase component image into a plurality of frequency components; performing a deconvolution process to each of the frequency components using an optical response character corresponding to each, and calculating phase distribution of a refraction component and phase distribution of a structure component; and calculating phase distribution of the sample by compounding the phase distribution of the refraction component and the phase distribution of the structure component.

Abstract: The present invention provides a novel simple, portable, compact and inexpensive approach for interferometric optical thickness measurements that can be easily incorporated into an existing microscope (or other imaging systems) with existing cameras. According to the invention, the interferometric device provides a substantially stable, easy to align common path interferometric geometry, while eliminating a need for controllably changing the optical path of the beam. To this end, the inexpensive and easy to align interferometric device of the invention is configured such that it applies the principles of the interferometric measurements to a sample beam only, being a single input into the interferometric device.

Abstract: Methods and systems for splitting an initiated signal are disclosed. An exemplary system may include a transmitter configured to selectively transmit an initiated signal, and a signal splitter in communication with the transmitter. The signal splitter may be configured to selectively split the initiated signal into a plurality of recipient signals for a plurality of recipient lines in communication with the transmitter. The signal splitter may be configured to selectively modify a number of recipient signals, e.g., by adjusting a spot size of the initiated signal on the signal splitter.

Abstract: An apparatus for testing an optical test piece comprising an interferometer for emitting an incident light beam. The apparatus includes a first reflective optic that receives the incident beam and produces a first reflected beam by focusing and expanding the received incident beam. The apparatus also includes a second reflective optic that receives and collimates the first reflected beam and outputs the collimated beam toward the optical test piece. Both the first and the second reflective optics are fixed to their respective positions relative to a thermally insensitive platform and the optical test piece is docked to the thermally insensitive platform and can be removed.

Abstract: An aspheric face form measuring method calculates phase information of interference light from light intensity of a fringe pattern image obtained by detecting interference light that is formed by measurement light and reference light reflected off a subject aspheric face being overlaid. The method changes a relative distance between an optical system and the subject aspheric face and transitions a position of a null region. The method performs calculation of form data for a vertical incident region where measurement light is vertically incident to the subject aspheric face, using phase information and a scanning amount. The method performs calculations of form data, of the null regions, a non-vertical incident region that is outside of the vertical incident region. The method also composites a plurality of partial form data of the subject aspheric face previously calculated, using each of a plurality of the phase information and scanning amounts.

Abstract: Methods and apparatus for pixel multiplication in optical imaging systems. In one example, an expanded optical point spread function, referred to as a code spread function, is used to phase modulate an incident electromagnetic wavefront, and digital processing, including correlation techniques, are used to filter and process the modulated wavefront to recover sub-pixel information from an image produced by the wavefront on a pixilated detector array.

Abstract: Disclosed is a system and method for characterizing optical materials, using steps and equipment for generating a coherent laser light, filtering the light to remove high order spatial components, collecting the filtered light and forming a parallel light beam, splitting the parallel beam into a first direction and a second direction wherein the parallel beam travelling in the second direction travels toward the material sample so that the parallel beam passes through the sample, applying various physical quantities to the sample, reflecting the beam travelling in the first direction to produce a first reflected beam, reflecting the beam that passes through the sample to produce a second reflected beam that travels back through the sample, combining the second reflected beam after it travels back though the sample with the first reflected beam, sensing the light beam produced by combining the first and second reflected beams, and processing the sensed beam to determine sample characteristics and properties.

Abstract: A wavefront measurement method includes the steps of causing object light to be incident on a Shack-Hartmann sensor, capturing a first spot image under an image pickup condition, calculating data of first spot positions that correspond to the first spot image, calculating second spot positions by simulating a second spot image on the basis of the image pickup condition and information of a travelling direction of diffracted light generated when the object light passes through the microlenses, and reducing detection errors of the spot positions by correcting the data of the first spot positions on the basis of data of the second spot positions including data of a detection error due to the diffracted light.

Abstract: A method for zero-contact measurement of the topography of a spherically or aspherically curved air-glass surface of an optical lens or lens combination, distinguished in that the surface (S1) to be measured is sampled on its glass rear side with an optical measurement beam through the air-glass surface (S2) lying before it in the measurement direction.

Abstract: Apparatus and methods for detecting optical profile are disclosed herein. In one embodiment, an apparatus includes a laser, a beam splitter, a collimation optical unit, first and second holders respectively holding a first test flat mirror and a second test flat mirror, a phase shifter connected with the first holder, and an angular measurement unit for measuring an angular error of the first test flat mirror and the second test flat mirror on the two holders. The first test flat mirror has a first test flat and the second test flat mirror has a second test flat. The apparatus further includes a planar imaging unit for generating the interfered test light having a direction generally along an x-axis direction of the first test flat and an x-axis direction of the second test flat and a convergence optical unit for projecting the interfered test light onto a detector.

Abstract: Methods for measuring the image quality of a projection objective include providing a measuring structure on an image-side of the projection objective, providing an immersion fluid between the projection objective and the measuring structure, directing light through the projection objective and the immersion fluid to the measuring structure while shielding the measuring structure from the immersion fluid, detecting light transmitted by the measuring structure, and determining an image quality of the projection objective based on the detected light.

Abstract: A transmitted wavefront measuring method comprises the steps of emitting light 101 from a light source 100 onto an object to be measured 120 to receive interfering light transmitted through the object and a diffraction grating 130 on a light receiving portion 140 disposed at a predetermined distance from the diffraction grating to measure an intensity distribution of the interfering light T10, performing a Fourier transform of the intensity distribution to calculate a frequency distribution T20, and obtaining a transmitted wavefront of the object based on a primary frequency spectrum in the frequency distribution T30 to T90. The step of obtaining the transmitted wavefront comprises the steps of performing an inverse Fourier transform of the primary frequency spectrum with reference to a grating frequency of the diffraction grating to calculate a complex amplitude of the interfering light T60, and obtaining the transmitted wavefront based on the complex amplitude T90.

Abstract: A circular common-path point diffraction interference wavefront sensor includes an optical matching system, a beam-splitter, a first reflection mirror, a second reflection mirror, a first Fourier lens, a second Fourier lens, a charge-coupled device (CCD) detector, a computer system, and a two-pinhole mask having a reference pinhole and a testing window and placed at a confocal plane of the first Fourier lens and the second Fourier lens. A testing beam is divided into two beams through the beam-splitter. One beam makes the pinhole diffraction by the reference pinhole, thereby producing the approximately ideal plane wave as the reference wave. Another beam passes through the testing window almost without any attenuation as the signal wave. The spatially linear carrier frequency is introduced by adjusting the tilt angle of the beam-splitter. The present invention is adapted for all kinds of dynamic and static detection field of wavefront phase.

Abstract: A method for measuring spacings between optical surfaces of a multi-lens optical system includes detecting the centring state of the optical system by taking into consideration all optical surfaces of the optical system. Then the optical system is adjusted in such a way, taking the centring state into consideration, that the optical axis of the optical system is aligned as far as possible with a reference axis. In a next step the spacings between the optical surfaces are determined with the aid of a short-coherence interferometer. The measuring-light ray directed onto the optical system for this purpose runs likewise along the reference axis.

Abstract: Provided is a measurement method or apparatus that can reduce the time for measuring the shape of an entire test surface. Each of a plurality of measurement ranges is set so that one measurement range overlaps a portion of at least another measurement range to form an overlap region, each measurement range being a portion of the test surface. Then, the shape of the test surface is measured at a first resolution in a first measurement range among the plurality of measurement ranges, and is measured at a second resolution in a second measurement range. Pieces of data of the shapes of the test surface in the plurality of measurement ranges are stitched together using the resulting measurement data to calculate the shape of the test surface.

Abstract: Disclosed are an ambient light reflection determination apparatus and an ambient light reflection determination method enabling to determine reflection without using an edge and even in a case where luminance of a reflection generating part in eyeglasses is low. In a reflection determination apparatus (100), a luminance histogram calculation section (102) calculates a luminance histogram representing a luminance distribution of an eye area image, a difference calculation section (104) calculates a difference histogram by finding a difference between the two luminance histograms calculated from the two eye area images having different photographing timings, an evaluation value calculation section (105) calculates an evaluation value regarding reflection of ambient light based on the difference histogram and a weight in accordance with luminance, and a reflection determination section (107) determines the reflection of ambient light based on the calculated evaluation value.

Abstract: Immersion objective arrangement including an objective, an immersion medium and an optical scattering disk, and associated method. The optical scattering disk includes a transparent substrate (1) and a light scattering layer (2) adjoining a surface of the substrate and having light-scattering-active particles (3). The light scattering layer has an embedding medium (4) which is optically denser than air and directly adjoins the facing surface of the substrate without intervening air gaps and by which the light-scattering-active particles are surrounded. Such optical scattering disks may be used, e.g., in apparatuses for wavefront measurement of high-aperture microlithography projection objectives employing lateral shearing interferometry.

Abstract: Measuring a shape of an optical surface (14) of a test object (12) includes: providing an interferometric measuring device (16) generating a measurement wave (18); arranging the measuring device (16) and the test object (12) consecutively at different measurement positions relative to each other, such that different regions (20) of the optical surface (14) are illuminated by the measurement wave (18); measuring positional coordinates of the measuring device (16) at the different measurement positions in relation to the test object (12); obtaining surface region measurements by interferometrically measuring the wavefront of the measurement wave (18) after interaction with the respective region (20) of the optical surface (14) using the measuring device (16) in each of the measurement positions; and determining the actual shape of the optical surface (14) by computationally combining the surface region measurements based on the measured positional coordinates of the measuring device (16) at each of the measurem

Abstract: Methods for measuring the image quality of a projection objective include providing a measuring structure on an image-side of the projection objective, providing an immersion fluid between the projection objective and the measuring structure, directing light through the projection objective and the immersion fluid to the measuring structure while shielding the measuring structure from the immersion fluid, detecting light transmitted by the measuring structure, and determining an image quality of the projection objective based on the detected light.

Abstract: A method of testing figure quality of a convex mirror in which an optical quality substrate material is used. Three separate interferometric null tests are carried out to produce three independent sets of optical path difference (OPD) data. Null lenses, or nulling computer generated holograms (CGHs), are designed and used as needed in each test setup so that spherical aberration is corrected. From the three sets of OPD data, surface figure errors on the rear and front surfaces of the test optic are calculated as well as the OPD error introduced by refractive index inhomogeneity in the substrate material. The rear surface is then corrected, generally using a computer-controlled polishing machine, to reduce rear surface errors to a manageably small level. The front convex surface of the test optic is then corrected to reduce surface figure error to within some specified amount.

Abstract: A Talbot interferometer includes a diffraction grating, an image pickup device, a moving unit configured to move at least one of the diffraction grating and the image pickup device in an optical axis direction of the test object, and a computer configured to adjust a position of the at least one of the diffraction grating and the image pickup device using the moving unit so that a Talbot condition can be met, based on a spatial frequency spectrum obtained from a plurality of interference fringes captured by the image pickup device while moving the at least one of the diffraction grating and the image pickup device using the moving unit.

Abstract: A measuring system for the optical measurement of an optical imaging system, which is provided to image a pattern arranged in an object surface of the imaging system in an image surface of the imaging system, comprises an object-side structure carrier having an object-side measuring structure, to be arranged on the object side of the imaging system; an image-side structure carrier having an image-side measuring structure, to be arranged on the image side of the imaging system; the object-side measuring structure and the image-side measuring structure being matched to each other in such a way that, when the object-side measuring structure is imaged onto the image-side measuring structure with the aid of the imaging system, a superposition pattern is produced; and a detector for the locally resolving acquisition of the superposition pattern. The imaging system is designed as an immersion system for imaging with the aid of an immersion liquid.

Abstract: A surface profile measuring apparatus includes a first image pickup device that obtains an interference pattern, an optical system that guides a measuring beam and a reference beam to the first image pickup device, a second image pickup device with which a distribution of light quantity of a beam from a light source traveling thereto avoiding the optical system is measured, and an arithmetic unit that calculates a profile of a target surface from the interference pattern. A distribution of light quantity of a beam from the light source transmitted through the optical system is measured with the first image pickup device. The profile of the target surface calculated by the arithmetic unit is corrected on the basis of the distributions of light quantity measured with the first and second image pickup devices.

Abstract: The present invention provides a measurement apparatus including a reflector configured to reflect a light traveling from an optical system, a detector configured to detect a light incident thereon via the reflector and a measurement optical system including one of a reference surface and a wavefront conversion element, and a load application device configured to apply a load to the reflector in an application direction perpendicular to the optical axis, the load application device applying a compression load to a first portion of the reflector below the optical axis, at a magnitude corresponding to an angle and a position of the first portion, in the application direction thereat, and applying a tension load to a second portion of the reflector above the optical axis, at a magnitude corresponding to an angle and a position of the second portion, in the application direction thereat.

Abstract: A measurement apparatus, which measures a wavefront aberration of an optical system to be measured, comprises: a calculation unit configured to calculate the wavefront aberration based on an interference fringe generated by light which passed through the optical system to be measured; and a determination unit configured to calculate an evaluation value indicating a wavefront state based on the wavefront aberration calculated by the calculation unit, and determine the calculated wavefront aberration as the wavefront aberration of the optical system if the evaluation value falls within an allowable range.

Abstract: An apparatus measuring wavefront aberration of an optical system includes a first mask in an object plane and having plural openings, an illumination optical system illuminating the openings of the first mask by using light from a light source, a second mask in an image plane and having an opening allowing passage of light containing aberration of the optical system and a pinhole/slit. The apparatus takes an image of interference fringe generated by light having passed through the optical system and the pinhole/slit and the light having passed through the optical system and the opening of the second mask, calculates an evaluation value to evaluate a state of the interference fringe by using image data of the image, determines, based on the evaluation value, whether the wavefront aberration of the inspected optical system is to be calculated, and calculates the wavefront aberration of the optical system from the image data.

Abstract: A wavefront-aberration-measuring device measures wavefront aberration of a to-be-tested optical system and includes a diffraction grating that splits light transmitted through the optical system, a detecting unit that detects interference fringes produced by beams of the split light, an arithmetic unit that calculates the wavefront aberration from the detected interference fringes, an image-side mask insertable into and retractable from an image plane of the optical system, and an illuminating unit that incoherently illuminates the image-side mask. The image-side mask has an aperture with a diameter larger than ?/2NA, where ? denotes a wavelength of the illuminating unit and NA denotes a numerical aperture of the to-be-tested optical system. The arithmetic unit calculates the wavefront aberration of the optical system from the interference fringes detected with the image-side mask being retracted from the image plane and the interference fringes detected with the image-side mask being in the image plane.

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: Embodiments of the present invention relate to techniques for improving optofluidic microscope (OFM) devices. One technique that may be used employs surface tension at a hydrophobic surface to passively pump the fluid sample through the fluid channel. Another technique uses electrodes to adjust the position of objects in the fluid channel. Another technique computationally adjusts the focal plane of an image wavefront measured using differential interference contrast (DIC) based on Young's interference by back propagating the image wavefront from the detection focal plane to a different focal plane. These techniques can be employed separately or in combination to improve the capabilities of OFM devices.

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: The present invention provides an exposure apparatus comprising a projection optical system configured to project a pattern of a reticle onto a substrate, a stage configured to move the substrate; and a sensor unit which is arranged on the stage and configured to receive light having passed through the projection optical system, the sensor unit including an aperture plate which is configured to be used in measuring different optical performances, and on which a plurality of aperture patterns with different shapes or different sizes are formed, and a photoelectric conversion device configured to photoelectrically convert the light beams from the plurality of aperture patterns.

Abstract: An imaging system for obtaining interferometric measurements from a sample spherical surface has a light source for providing an incident light beam, a beamsplitter disposed to direct the incident light beam toward the sample spherical surface and to direct a test light reflected from the sample spherical surface and a reference light reflected from a reference spherical surface toward an interferometric imaging apparatus. There is a lens assembly in the path of the incident light beam, with at least one lens element, wherein one of the at least one lens elements has an aspheric surface and wherein one of the at least one lens elements further provides the reference spherical surface facing the sample spherical surface. A reference plate is temporarily disposed in the path of the incident light beam for measuring the aspheric surface itself and is removable from the path of the incident light beam for obtaining interferometric measurements from the sample spherical surface.

Abstract: An apparatus and associated method for testing a non-symmetric (e.g., phi-polynomial) surface. The apparatus uses several simple (singlet) optical elements (e.g., an Offner null configuration) and a tilted optic under test in combination with an active optical element (e.g., actuated, deformable membrane mirror, optical phase modulator, etc.) that together form a null or quasi-null that allows for conventional null-based interferometry. This solution solves the problem of exceeding the dynamic range of a conventional interferometer when trying to test non-symmetric optical surfaces.

Abstract: A method comprises determining a first processing center position to calculate a wavefront aberration of an optical system, determining a second processing center position to calculate a wavefront aberration, correcting the first processing center position in a first direction using the second processing center position in the first direction and correcting the second processing center position in a second direction using the first processing center position in the second direction.