Abstract: According to examples, a fiber-optic testing source for testing a multi-fiber cable may include a laser source communicatively coupled to a plurality of optical fibers connected to a connector. The fiber-optic testing source may include at least one photodiode communicatively coupled to at least one of the plurality of optical fibers by at least one corresponding splitter to implement a communication channel between the fiber-optic testing source and a fiber-optic testing receiver. The communication channel may be operable independently from a polarity associated with the multi-fiber cable. The fiber-optic testing receiver may include a plurality of photodiodes communicatively coupled to a plurality of optical fibers.

Abstract: A method for calibrating the alignment of a wafer is provided. A plurality of alignment position deviation (APD) simulation results are obtained form a plurality of mark profiles. An alignment analysis is performed on a mark region of the wafer with a light beam. A measured APD of the mark region of the wafer is obtained in response to the light beam. The measured APD is compared with the APD simulation results to obtain alignment calibration data. An exposure process is performed on the wafer with a mask according to the alignment calibration data.

Abstract: An optical detection device and method for detecting temperature changes and/or wavelength changes of an optical probe signal includes transmitting an optical probe signal having a predetermined wavelength to an optical input port of an optical waveguide; detecting first and second optical detection signal at first and second optical output ports via first and second opto-electrical converters which create corresponding first and second electrical signals; measuring values of the first and second electrical signal and determining an absolute temperature or a temperature change of the optical waveguide and/or an absolute wavelength value or a wavelength change of the optical probe signal via values measured of the first and second electrical signals and first and second previously determined wavelengths and temperature dependencies of both first and second power transfer functions.

Abstract: The present invention is a passive receive module for use with an OTDR for determining polarity of a cable under test. Only one position of the module connector of the receive module includes a filling and all other positions are occupied with a reflective component with a reflective characteristic distinct from that of the filling. Only one position at the OTDR end of the cable will receive a distinct reflection from all of the other positions. Polarity may be determined from these positions.

Abstract: An overlay metrology system may scan a sample including inverted Moiré structure pairs along a scan direction, include an illumination sub-system to illuminate first and second Moiré structures of one of an inverted Moiré structure pair with common mutually coherent illumination beam distributions, and include an objective lens to capture at least +/?1 diffraction orders from sample, where a first pupil plane includes overlapping distributions of the collected light with an interference pattern associated with relative wavefront tilt. The system may also include a diffractive element in the first pupil plane, where one diffraction order associated with the first Moiré structure and one diffraction order associated with the second Moiré structure overlap at a common overlap region in a field plane, and a collection field stop located in the field plane to pass light in the common overlap region and block remaining light and remove the relative wavefront tilt.

Abstract: An overlay measurement apparatus that can quickly measure an overlay error between layers with a large height difference is provided. The overlay measurement apparatus measures an error between a first overlay mark and a second overlay mark formed in a pair on different layers of a wafer. The overlay measurement apparatus includes an imaging system configured to acquire alignment images of a pair of first and second overlay marks at a plurality of focus positions, and a controller communicatively coupled to the imaging system. The overlay measurement apparatus can rapidly and accurately measure an overlay error between layers with a large height difference.

Abstract: A multi-core fiber includes multiple optical cores, and for each different core of a set of different cores of the multiple optical cores, a total change in optical length is detected. The total change in optical length represents an accumulation of all changes in optical length for multiple segments of that different core up to a point on the multi-core fiber. A difference is determined between the total changes in optical length for cores of the set of different cores. A twist parameter and/or a bend angle associated with the multi-core fiber at the point on the multi-core fiber is/are determined based on the difference.

Abstract: A wafer shape metrology system includes a wafer shape metrology sub-system configured to perform one or more stress-free shape measurements on a first wafer, a second wafer, and a post-bonding pair of the first and second wafers. The wafer shape metrology system includes a controller communicatively coupled to the wafer shape metrology sub-system. The controller is configured to receive stress-free shape measurements from the wafer shape sub-system; predict overlay between one or more features on the first wafer and the second wafer based on the stress-free shape measurements of the first wafer, the second wafer, and the post-bonding pair of the first wafer and the second wafer; and provide a feedback adjustment to one or more process tools based on the predicted overlay. Additionally, feedforward and feedback adjustments may be provided to one or more process tools.

Abstract: The purpose of this invention is to provide an optical pulse testing method and optical pulse testing device capable of measuring the loss at an end farther than an axially misaligned connection point at which inter-mode crosstalk occurs independently from the crosstalk value at the point. In this optical pulse testing method, a matrix (loss and crosstalk) representing the mode coupling at a near-end connection point is calculated, and an OTDR waveform having the effects of crosstalk eliminated therefrom is obtained by numerical processing using the calculated matrix representing the mode coupling.

Abstract: A defective product determination method for a vehicle wheel includes: locating, as a locating step by a controller, a lowest point on a welding mark due to radiation of a laser beam within a target range from an inner peripheral surface of a wheel rim to a position spaced away by a specified distance inward in a radial direction of the vehicle wheel; and determining, as a determination step by the controller, that the vehicle wheel is a defective product when a defective product determination condition is satisfied. The defective product determination condition includes, as a necessary condition, a condition that a relative distance of the lowest point with respect to the inner peripheral surface of the wheel rim in the radial direction of the vehicle wheel is equal to or smaller than a reference distance.

Abstract: In some examples, parallel optics based optical time domain reflectometer acquisition may include a laser array operatively collimated to an optical fiber array to transmit, in parallel, a plurality of laser beams to optical fibers of the optical fiber array. A photodiode array may receive, in parallel, backscattered and reflected light from the optical fiber array. The photodiode array may determine, based on the backscattered and reflected light, properties of the optical fibers of the optical fiber array.

Abstract: An apparatus includes optical fiber ports into which optical fiber channels are input, the optical fiber channels carrying and outputting light, a mask configured to, while spinning at a frequency, allow a first portion of the light incident on the mask to pass through the mask, and block a remaining portion of the light incident on the mask, based on a pattern on the mask, and a photodetector configured to detect the allowed first portion of the light as input signals. The apparatus further includes a testing device configured to transform the input signals to a frequency domain, to obtain measured signals in frequencies respectively corresponding to the optical fiber channels, and determine whether each of the measured signals is a failure by comparing the obtained measured signals with a threshold signal.

Abstract: The present invention is to provide a backscattered light amplification device, an optical pulse test apparatus, a backscattered light amplification method, and an optical pulse test method for amplifying a desired propagation mode of Rayleigh backscattered light with a desired gain by stimulated Brillouin scattering in a fiber under test having the plurality of propagation modes. The backscattered light amplification device according to the present invention is configured to control individually power, incident timing, and pulse width of a pump pulse for each propagation mode when the pump pulse is incident in a plurality of propagation modes after the probe pulse is input to the fiber under test in any propagation mode.

Abstract: An overlay metrology system may include an illumination source and illumination optics to illuminate an overlay target on a sample with illumination from the illumination source as the sample is in motion with respect to the illumination from the illumination source in accordance with a measurement recipe. The overlay target may include one or more cells, where a single cell is suitable for measurement along a particular direction. Such a cell may include two or more gratings with different pitches. Further, the system may include two or more photodetectors, each configured to capture three diffraction lobes from the two or more grating structures. The system may further include a controller to determine an overlay measurement associated with each cell of the overlay target.

Abstract: A method of testing a photonics die at the wafer level includes providing a sacrificial waveguide and a grating coupler at least partially in a scribe line between dies of a wafer, performing one or more tests on the dies of the wafer via the sacrificial waveguide and grating coupler in the scribe line, and removing the sacrificial waveguide during separation of the dies of the wafer.

Abstract: A method for semiconductor metrology includes depositing a first film layer on a semiconductor substrate and a second film layer overlying the first film layer. The first and second film layers are patterned to define a plurality of overlay targets comprising first target features formed in the first film layer having respective first locations, which are spaced apart by first nominal distances, and second target features formed in the second film layer having respective second locations, which are spaced apart by second nominal distances, which are different from the first nominal distances. An image of the semiconductor substrate is processed to measure respective displacements between the first and second target locations in each of the overlay targets, and to estimate both an actual overlay error between the patterning of the first and second film layers and a measurement error of the imaging assembly.

Abstract: A light table apparatus and inspection methods are provided for detecting fluid-transmitting defects in heat exchanger plates using light. The method includes positioning the heat exchanger plate on top of a support frame of the apparatus, and covering peripheral portions of the heat exchanger plate with at least one light-shielding element. In some examples, the light-shielding element may be edge mats that cover peripheral portions of the plate, or alternatively, may be a gasket-like template that engages a resilient light seal with profiles of the heat exchanger plate surrounding a central portion thereof. The ambient environment is darkened and illumination units in the support frame are activated, and light energy can only be transmitted through defects in the central portion. Thus, a quick manual inspection process is provided for such plates, and defects as small as 15 microns are accurately detected when using the light table apparatus and inspection methods.

Abstract: The present invention relates to a device for measuring an optical element comprising: a. a light source, b. a measurement structure which illuminated by the light of the light source and has areas of different transmissivity, c. an optical imaging system for converting light transmitted by the measurement structure into a collimated measuring beam which is directed onto the optical element, and d. a sensor for detecting a reflection of the measuring beam generated on the optical element for detecting a transmission of the measuring beam passing through the optical element. According to the invention the light source has a plurality of light segments, wherein the device further comprises a control unit which is designed for independently controlling the plurality of light segments. The invention further relates to a corresponding method for measuring an optical element.

Abstract: An assembly includes a base member having a fiducial marker, a vehicle component having a housing mounted to the base member, and an image sensor fixed to the housing and aimed at the fiducial marker. A method includes mounting the vehicle component to the base member of a vehicle, capturing a baseline image of the fiducial marker, capturing a subsequent image of the fiducial marker, comparing the subsequent image to the baseline image, and adjusting operation of the vehicle component in response to the identification of differences between the baseline image and the subsequent image.

Abstract: A control apparatus includes an angle control unit configured to change a tilt angle by tilting an imaging sensor, a first determination unit configured to determine a first area from among a plurality of areas in an image, an evaluation value acquisition unit configured to acquire a contrast evaluation value of each of second areas excluding the first area among the plurality of areas by changing the tilt angle through the angle control unit, and a second determination unit configured to determine the tilt angle for each area based on the contrast evaluation value acquired by the evaluation value acquisition unit, and determining the tilt angle of the image sensor based on the tilt angle determined for each area. The angle control unit tilts the image sensor so as to obtain the tilt angle determined by the second determination unit.