Abstract: A shape measuring device includes a light source unit, a light splitting unit, a reference mirror, a light receiving unit and a processing unit. The light source unit generates light and can change the wavelength of the light. The light splitting unit splits the light generated from the light source unit into at least a reference light and a measurement light. The light receiving unit receives the reference light which is reflected by the reference mirror so as to form a reference light path, and the measurement light which is reflected by a light-transmitting target object formed on a substrate so as to form a measurement light path. The processing unit calculates the shape of the measurement argent object based on an interference change resulting from a wavelength change of the light between the reference light and the measurement light received by the light receiving unit.

Abstract: The present disclosure provides apparatus and methods for overlay measurement. An exemplary overlay measurement apparatus includes an illuminating unit configured to generate illuminating light to illuminate a first overlay marker formed on a wafer to generate reflected light; and a first measuring unit configured to receive the reflected light from the first overlay marker to cause the reflected light to laterally shift and shear to generate interference light, to receive the interference light to form a first image, and to determine existence of an overlay offset and an exact value of the overlay offset, according to the first image.

Abstract: A method and system to measure misalignment error between two overlying or interlaced periodic structures are proposed. The overlying or interlaced periodic structures are illuminated by incident radiation, and the diffracted radiation of the incident radiation by the overlying or interlaced periodic structures are detected to provide an output signal. The misalignment between the overlying or interlaced periodic structures may then be determined from the output signal.

Abstract: The present disclosure provides a method for improving capability of resisting image noise of a co-phasing system of a dispersed fringe sensor. The method comprises the following steps: carrying out a coarse co-phasing adjustment by utilizing the dispersed fringe sensor until the coarse co-phasing is stabilized in a closed loop; collecting a two dimensional dispersed fringe image by the dispersed fringe sensor; superposing the dispersed fringe image along a dispersed direction so as to convert the two dimensional dispersed fringe image to a one dimensional image along an interferential direction; extracting peak values of the main peak, a left side lobe and a right side lobe of the one dimensional image along the interferential direction, and calculating corresponding piston error value of the image by carrying out a Left-subtracting-right LSR algorithm on these peak values.

Abstract: A transmission spectroscopy device can direct light into a sample, and determine properties of the sample based on how much light emerges from the sample. The device can use a cell to contain the sample, so that the size of the cell defines the optical path length traversed by light in the sample. To ensure accuracy in the measurements, it is beneficial to calibrate the device by measuring the size of the cell periodically or as needed. To measure the size of the cell, the device can perform a transmission spectroscopy measurement of a known substance, such as pure water, to produce a measured absorbance spectrum of the known substance. The device can subtract a known absorbance spectrum of the known substance from the measured absorbance spectrum to form an oscillatory fringe pattern. The device can determine the size of the cell from a period of the fringe pattern.

Abstract: An interferometric measurement method precisely determines parallelism and 3D position of guide pin holes and fiber holes in multi-fiber ferrules used in connectors. The parallelism and position are measured for the ferrule with inserted reference guide pins and reference fibers by scanning the ferrule from side in an interferometric system. Fiber hole deviations from designated locations on the ferrule end face and distance between the fiber holes and the guide pin holes are calculated as well.

Abstract: Techniques and devices for optical sensing of rotation based on measurements and sensing of optical polarization or changes in optical polarization due to rotation without using optical interferometry. In implementations, a device for optical sensing of rotation can include a detection device that includes: (1) a beam splitter that splits the optical output into four optical beams; (2) four detection modules that receive the four optical beams, respectively, to obtain measurements of four different optical Stokes parameters from the four optical beams, respectively, and (3) a processing unit that processes the measurements of four different optical Stokes parameters to determine a rotation angle of a state of polarization of the optical output and a differential phase shift between the first and the second optical beams caused by a rotation experienced by the optical loop.

Abstract: Apparatus and method for obtaining a plurality of spectral images of a source object in a snapshot using comprising two-dimensional compressed sensing data cube reconstruction (2D CS-SCR) applied to a dispersed-diffused snapshot image. In some embodiments, the snapshot image is obtained through a RIP diffuser. In some embodiments, a randomizer is used to further randomized the dispersed-diffused snapshot image. The 2D CS-SCR includes applying a 2D framelet transform separately to arrays representing different wavebands of spectral cube data derived from the snapshot image. The application of the 2D framelet transform separately to the arrays representing the different wavebands includes application of direct and inverse 2D framelet transforms to the arrays. In some embodiments, the direct and inverse framelet transforms are included in a split Bregman iteration.

Abstract: The invention provides an illuminance measuring system, which comprises an illuminance measuring instrument which comprises a first communication unit and is moved by a moving vehicle, a position measuring means which comprises a second communication unit and is capable of measuring a three-dimensional position of the illuminance measuring instrument and a data collector which comprises a third communication unit and a storage unit for storing positional information data of a predetermined measuring point, wherein the data collector moves the moving vehicle to the measuring point based on a position of the illuminance measuring instrument as measured by the position measuring means and the positional information data, an illuminance is measured by the illuminance measuring instrument and a position of the illuminance measuring instrument at the time of illuminance measurement is measured by the position measuring means, and wherein the data collector obtains an illuminance measurement result from the illumina

Abstract: The machine includes a rotational mounting bracket, upon which an agricultural disc is supported and held. A hold-down plate that can rotate freely is arranged above the mounting bracket. A linear actuator displaces the hold-down plate vertically in a downwards direction to press the agricultural disc. A laser measurement device is coupled to a linear guide where the hold-down plate forms part of a rotational head-piece fixed to a rod of the linear actuator. A method includes determining a central reference height on a model disc, determining the height of points in the periphery of the disc to be measured, calculating the average of the measured heights and comparing with the central reference height to determine whether the disc is valid or not.

Abstract: A system and method of characterizing through-focus visual performance of an IOL using metrics based on an area under the modulation transfer function for different spatial frequencies at different defocus positions of the IOL. Also disclosed is a system and method of characterizing through-focus visual performance of an IOL using a metric based on an area under a cross-correlation coefficient for an image of a target acquired by the IOL at different defocus positions of the IOL.

Abstract: The invention relates to a measuring frame (106) for optically ascertaining a perforation position of a projectile (134) through a target surface (102) in a contactless manner. In addition, the invention relates to a corresponding measurement and analysis method. The invention further relates to a display system which uses at least one such measuring frame (106). The measuring frame comprises at least one first (120) radiation source for emitting a first diverging radiation field, at least one second radiation source for emitting a second diverging radiation field, said first and second radiation fields intersecting at an angle on a plane transverse to a perforation direction, and at least one first (126) and at least one second (126?) optical receiving device, which are paired with the at least one first and second radiation source, respectively.

Abstract: A method for measuring a position of an object, the method includes probing a sensing mark arranged in a first plane on a substrate to determine the position of the object, a portion of the substrate connecting the sensing mark to the object. An edge of the object can be sufficiently close to an edge of the sensing mark to reduce measurement errors in the position of the object caused by a deformation of the substrate.

Abstract: A device for position determination includes a light source and a planar measurement reflector movable along a measurement direction oriented perpendicular to the measurement reflector. A detector device is disposed such that a beam emitted by the light source strikes the detector device after impinging on the measurement reflector so that, in an event of a movement of the measurement reflector along the measurement direction, a signal results which is dependent on a position of the measurement reflector and from which a reference signal is generatable at a defined reference position. A deflection unit is disposed so as to deflect the beam such that the beam strikes the measurement reflector twice and therebetween passes through the deflection unit. The deflection unit is arranged so that a deviation in beam direction, resulting after the first reflection from a tilt of the measurement reflector, is compensated after the second reflection.

Abstract: The invention discloses a technique that estimates micro roughness from a total sum of detection signals from plural detection systems and signal ratios, using a light scattering method. The technique rotates and translates a wafer at high speed to measure the entire surface of the wafer with high throughput. The relationship between the micro roughness and the intensity of scattered light varies according to a material of the wafer and a film thickness thereof. Moreover, calibration of an apparatus is also necessary. Thus, for instance, the invention provides a technique that has a function of correcting an optically acquired detection result using a sample which is substantially the same as a measurement target and makes the optically acquired detection result come close to a result measured by an apparatus, such as an AFM, using a different measurement principle.

Abstract: Apparatus for measuring the distribution of strain and temperature along an optical fibre (34) by analysing the distribution of the Rayleigh scattering and stimulated Brillouin scattering wavelength shifts along the length of a sensing fibre (34) using a Wavelength-Scanning Optical Frequency-Domain Analysis (WS-BOFDA) technique in which a wavelength-swept laser (12) sources a Brillouin “pump” radiation and excites a Brillouin ring laser (14) that sources a Brillouin “stimulus” radiation with wavelength shifted with respect to the excitation of a tuneable quantity. One optical Mach Zehnder or Michelson interferometer (27) is excited by the “stimulus” radiation on both the measurement arm, that comprises the sensing fibre (34), and the reference arm (38) while the “pump” radiation is injected only in the measurement arm by a controllable inhibition system (57).

Abstract: A tool for detecting deformation of a nominally straight element includes a first body element having first straight edge, means for biasing the first straight edge against the straight element, and a light source arranged to illuminate any space present between the straight element and the first straight edge of the first body element.

Abstract: A device for assisting the aligning of a patient support dockable onto an operating table is provided A sensing unit is configured to be arranged on the patient support or the operating table and configured to sense a feature of the patient support and/or of the operating table, said feature lying opposite the sensing unit. The sensing unit configured to sense a position-dependent physical interaction and herefrom to generate a signal that depends on the spatial relative position between the patient support and the operating table. An evaluating unit is configured to receive the signal from the sensing unit and to generate an output that characterizes the relative position between the operating table and the patient support.

Abstract: A method for determining receiver coupling efficiency includes varying optical power inputted into a half active optical cable to determine a maximum optical power at which the TIA squelches and determining a receiver coupling efficiency by calculating a ratio of a threshold optical power to the maximum optical power at which the TIA squelches. A method of determining link loss in a channel includes varying optical power of a light source to determine the maximum optical power at which the TIA squelches and determining the link loss in the channel by subtracting the maximum optical power from the threshold optical power. A method of determining link topology includes selecting a pattern of optical powers and matching a pattern of squelched and non-squelched outputs with the pattern of optical power. An active optical cable includes memory storing a value related to an initial link loss of the active optical cable.

Abstract: The present invention provides a meter and method of use for measuring an optical attenuation coefficient in a liquid medium. In operation, a collimated beam, produced by a laser of the attenuation meter apparatus, propagates thru the liquid medium with filtered back-scattered light arriving at a camera of the meter. A light image is formed at a focal plane of the camera. The light image is recorded and analyzed by a microcomputer to provide optical beam attenuations coefficients.