Abstract: In some implementations, a Mach-Zehnder interferometer (MZI) includes a delay line arm formed in a chip and a mirrored facet formed in the chip. The delay line arm may be configured to propagate light to the mirrored facet. The mirrored facet may be configured to reflect, to the delay line arm, a percentage of the light propagated to the mirrored facet by the delay line arm.

Abstract: A method for determining a contour of a frame groove in a rim of a spectacle frame includes illuminating the rim, capturing a plurality of images of the illuminated rim from different predetermined perspectives, evaluating the captured images, and determining a spatial curve of the frame groove based on the evaluated images. The rim is illuminated along the entire circumference of the rim by directed illumination. Moreover, the evaluation of the captured images includes assigning each portion contained in the captured images to a respective surface element of the frame groove on the basis of at least one of the following properties: shadowing of the respective portion, brightness of the respective portion and phase angle of the illumination of the respective portion. Moreover, an apparatus, a computer program, a method for grinding a spectacle lens, and a computer-implemented method for determining a geometry of a spectacle lens are disclosed.

Abstract: An analyte in water is quantified by mixing an internal standard with a water sample. The sample is analyzed with a Raman spectrometer. The analysis includes mapping the signal from the Raman spectrometer to the quantity of said analyte. The mapping can include using a calibration curve, for example a multivariate calibration curve, that was previously prepared with the internal standard. In other examples, a sample is measured after addition of a known amount of the analyte.

Abstract: An apparatus and method for aligning two coaxially coupled rotatable shafts. A servo operated multi axis positioning device is movable along a longitudinal axis parallel to the axis of the shafts, and movable vertically to position a laser range (LRF) adjacent to the two shafts, which measures the distance between the LRF and a spot on the shafts. A controller having a processor and memory communicates with the positioning device and the LRF to collect data at two axial positions on each shaft. At each position the LRF measures the distance to the shaft and stores the measurement and location data. The LRF is vertically repositioned and the measurement and storing steps are repeated over a scan distance sufficient to provide enough data to determine the location of the shaft center. The processor then calculates and compares the shafts centerlines and determines the necessary adjustments needed to move the shafts into coaxial alignment.

Abstract: A LiDAR sensor unit is configured to detect information of an outside area of a vehicle with sensing light. A cover covers the LiDAR sensor unit so as to allow passage of the sensing light while forming a part of an outer surface of the vehicle. A strain gage is disposed on the cover and configured to output a strain signal corresponding to strain generated in the cover. A processor is configured to detect a foreign substance adhered to the cover based on the strain signal.

Abstract: An interferometer for use in remote sensing systems includes a beam splitter that separates an input wave into a reflected wave, which travels along a first optical path within an upper interferometer arm, and a transmitted wave, which travels along a second optical path within a lower interferometer arm. The reflected and transmitted waves are subsequently recombined by the beam splitter for imaging onto a sensor. A highly dispersive element is incorporated into at least one of the pair of interferometer arms. Due to anomalous dispersion, a frequency shift in a wave transmitted through a dispersive element changes the optical path length within its corresponding arm. As a result, the recombined wave produces an interference pattern with a measurable phase change that can be utilized to calculate the original frequency shift in the input wave with great precision and potential sub-Hertz sensitivity.

Abstract: According to an example aspect of the present invention, there is provided a sample container for use inside an optically integrating cavity, comprising an enclosing member comprised of fluorocarbon plastic, the enclosing member having diffuse transmittance of at least 80% and the sample container being adapted to contain a solid or liquid sample.

Abstract: A catheter system for optical coherence tomography includes an elongate catheter body, an optical fiber in the elongate catheter body, and an anamorphic lens assembly coupled with a distal end of the optical fiber. The optical fiber and the lens assembly are together configured to provide a common path for optical radiation reflected from a target and from a reference interface between the distal end of the optical fiber and the lens assembly.

Abstract: An optical system including an enclosure including a front end and a rear end, a first pair of apertures configured to be disposed on a front plane on the front end of the enclosure and a single optical lens system disposed between the front end and the rear end of the enclosure, wherein the first pair of apertures are configured to allow sets of light rays into the enclosure through the single optical lens system to be cast on an image plane as first and second spots, the image plane being parallel to the front plane, if the first and second spots are concentrically disposed, the sets of light rays are determined to be parallelly disposed with respect to one another, otherwise the sets of light rays are determined to not be parallelly disposed with one another.

Abstract: A method is useable for determining a thickness of a cover slip or object carrier in a microscope, which has an objective facing toward a sample chamber. Two optical media border two opposing surfaces of the cover slip or object carrier and form two partially reflective interfaces, which are arranged at different distances from the objective. The method includes: deflecting a measurement light beam by the objective with oblique incidence on the cover slip or object carrier; generating two reflection light beams spatially separated from one another by the measurement light beam being partially reflected on each of the two interfaces; receiving the two reflection light beams by the objective and conducting them onto a position-sensitive detector; registering the incidence locations on the position-sensitive detector; and determining the thickness of the cover slip or object carrier based on the registered incidence locations.

Abstract: Disclosed is a method implemented by a computer, for determining the position of an optical lens member having a surface placed on a lens blocking ring, the blocking ring including a bearing zone arranged to bear at least partially a placed known surface of the optical lens member when the known surface of the optical lens member is placed on the lens blocking ring and hold by a force applied on the optical lens member, the method includes finding a trio of points of the bearing zone that forms a triangle including the projection on the main plane of the point of application of the force; and a position of the optical lens having a virtual contact between the placed known surface and the ring at the location of the trios of points.

Abstract: The present application discloses a method and apparatus for compensation of focal errors in laser beam measurement instruments that characterize beam parameters by analyzing images of Rayleigh scatter taken at multiple angles around the beam axis. If the laser beam is not precisely positioned, these images may not be in focus, and the instrument will not report accurate results. This method and apparatus finds the longitudinal axis of the beam by analyzing the beam location in at least two images. All images are subdivided into slices and distances from the beam axis to the focal plane for each slice are calculated and used to find an out-of-focus transfer function for each slice, which is used in combination with the modulation transfer function of the system to deconvolve the slice. Images formed by reassembling the deconvolved slices can then be analyzed to obtain the correct beam parameters.

Abstract: A method for characterising high aspect ratio (“HAR”) structures etched in a substrate includes, for at least one structure, an interferometric measurement step, carried out with a low-coherence interferometer positioned on a top surface of the substrate, for measuring with a measurement beam, at least one depth data relating to a depth of the HAR structure, and a first adjusting step for adjusting a diameter, at the top surface, of the measurement beam according to at least one top critical dimension (“top-CD”) data relating to a width of the HAR structure.

Abstract: A method for determining properties of a sample (12) by ellipsometry includes positioning the sample (12) in an ellipsometer (10) so that a surface normal (n) of a measurement region of the sample surface is tilted relative to a reference axis (z) of the ellipsometer (10) and measuring a Mueller matrix for the measurement region. The method then includes creating an equation system by equating the measured Mueller matrix and a matrix product formed of: a rotation matrix about an input rotation angle (?); an isotropic Mueller matrix in normalized NCS form and a rotation matrix about an output rotation angle (??). The method then solves the equation system for the parameters representing the sample properties to be determined. The input rotation angle (?) and the output rotation angle (??) are set as parameters independent of one another when setting up the equation system.

Abstract: A method and system implementing the method for characterising structures etched in a substrate, such as a wafer, includes at least one structure etched in the substrate, an imaging step including the following steps: capturing, with an imaging device positioned on the top surface of the substrate, at least one image of a top surface of the substrate, and measuring a first data relating to the structure from at least one captured image, at least one interferometric measurement step, carried out with a low-coherence interferometer positioned on the top surface, for measuring with a measurement beam positioned on the structure, at least one depth data relating to a depth of the structure; and a first adjusting step for adjusting the measurement beam according to the first data.

Abstract: A phase sensitive optical time domain reflectometry based distributed acoustic sensing system eliminating a degradation in a sensing performance encountered due to a finite extinction ratio of optical elements used to generate optical pulses is provided. A classical Optical Time Domain Reflectometer (OTDR) concept and a phase-OTDR concept are merged to generate an optic pulse for an interrogation with commercially available optic modulators. Characteristics of a light inside a fiber optic cable carry properties of both classical OTDR and phase-OTDR systems. The proposed solution does not require any modifications in a receiver part of the phase-OTDR systems and the proposed solution is used for any type of phase-OTDR system structure.

Abstract: Stationary devices employing quadrature phase analysis light scattering are provided, to aid in the determination of the magnitude and polarity of electrophoretic mobility and zeta potential of particles in colloids. The devices use an optical quadrature interferometer with an electrophoresis sample chamber containing sample particles undergoing electrophoresis, the optical quadrature interferometer being configured to generate a quadrature signal. The phase of the quadrature signal may be analyzed at the frequency of the sample chamber electric field to estimate displacements and directions of the particles. The estimates can be used to determine a central value of the magnitude of the electrophoretic mobility, as well as its polarity. Particles having low electrophoretic mobility, or that may be adversely affected by high electric fields, can be analyzed, and constraints on vibration and light source coherence length may be relaxed. A phase modulator or frequency shifter is not required.

Abstract: Disclosed are methods and systems correcting bulk-motion artifacts in phase-based functional OCT images. The disclosed methods and systems are based on the use of the standard deviation of the phase shift signal present in phase-based OCT imaging. When applied with functional OCT techniques such as OCT angiography, Doppler OCT, and OCT elastography, the disclosed methods provide improved image quality and decreased computational cost compared to other methods of bulk motion compensation.

Abstract: A measurement system and an inspection method for detecting a defective bonding interface in a sample substrate including at least one element disposed on a support. The method comprises: placing the sample substrate in the measurement system, establishing an inclination map of the exposed surface, analyzing the inclination map and identifying a zone or zones of the exposed surface whose inclinations deviate by more than a given threshold from the inclination of the reference surface; and detecting the presence of a defective bond between the element and the support, depending on the result of the analysis of the inclination map.

Abstract: An optical system may include a light source to provide a beam of light. The optical system may include a reflector to receive and redirect the beam of light. The optical system may include a light gate having an opening to permit the beam of light, from the reflector, to travel through the opening. The optical system may include a light sensor to receive a portion of the beam of light after the beam of light travels through the opening, and convert the portion of the beam of light to a signal. The optical system may include a processing device to determine whether a notch of a wafer is in an allowable position based on the signal.