A method, apparatus, and system are provided to monitor and characterize the dynamics of a phase change region (PCR) created during laser welding, specifically keyhole welding, and other material modification processes, using low-coherence interferometry. By directing a measurement beam to multiple locations within and overlapping with the PCR, the system, apparatus, and method are used to determine, in real time, spatial and temporal characteristics of the weld such as keyhole depth, length, width, shape and whether the keyhole is unstable, closes or collapses. This information is important in determining the quality and material properties of a completed finished weld. It can also be used with feedback to modify the material modification process in real time.

Disclosed is a method and apparatus for determining information about an alignment of one or more optical components of a multi-component assembly involving: detecting an optical interference pattern produced from a combination of at least three optical wave fronts including at least two optical wave fronts caused by reflections from at least two surfaces of the one or more optical components; and computationally processing information derived from the detected optical interference pattern with at least one simulated optical wave front derived from a model of at least one selected optical surface of the at least two surfaces to computationally isolate information corresponding to an alignment of the selected optical surface.

Apparatus include a polarization state generator situated to provide an interferometer source beam with a region of polarized source light with a polarization state that is in-plane as subsequently incident on a sample and a region of polarized source light with a polarization state that is perpendicular to in-plane as subsequently incident on the sample, and an interferometer unit configured to split the interferometer source beam into test and reference arm beams, to direct the test arm beam to the sample and the reference arm beam to a reference surface, and to recombine the test and reference arm beams to produce an interferometer output beam. Methods use a polarization state generator to produce an interferometer source beam with a region of polarized source light with a polarization state that is in-plane as subsequently incident on a sample and a region of polarized source light with a polarization state that is perpendicular to in-plane as subsequently incident on the sample, and use an interferometer unit which splits the interferometer source beam into test and reference arm beams, directs the test arm beam to the sample and the reference arm beam to a reference surface, and recombines the test and reference arm beams to produce an interferometer output beam.

A wafer shape metrology system includes a wafer shape metrology sub-system configured to perform one or more stress-free shape measurements on a bonded pair of wafers, where the bonded pair of wafers are bonded with a bonding tool. The wafer shape metrology sub-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; convert the stress-free shape measurements into an overlay distortion pattern; detect one or more localized deviations in the bonded pair of wafers in order to identify one or more contaminant particles on the bonding tool; and report the one or more localized deviations in the bonded pair of wafers.

A measurement apparatus for interferometric shape measurement of a test object surface. A test optical unit produces from measurement radiation a test wave for irradiating the surface. A reference element with an optically effective surface interacts with a reference wave also produced from the measurement radiation. An interferogram is produced by superimposing the test wave after interaction with the test object's surface. A holding device holds the reference element and moves the reference element relative to the reference wave in at least two rigid body degrees of freedom so that a peripheral point of the reference element's optically effective surface shifts by at least 0.1% of a diameter of the optically effective surface. The at least two degrees of freedom include a translational degree, directed transversely to a propagation direction of the reference wave and a rotational degree, whose rotational axis aligns substantially parallel to the reference wave's propagation direction.

An information processing apparatus that executes processing of obtaining, from an interference fringe image that is a two-dimensional distribution of intensity of interference fringes of object light and reference light, a phase difference image that is a two-dimensional distribution of a phase difference between the object light and the reference light, and obtaining a shape of an object to be observed based on the phase difference image includes at least one processor configured to acquire object-related information regarding the object to be observed, read out, from a storage unit in which the object-related information and a shape profile indicating the shape of the object to be observed are stored in association with each other, the shape profile corresponding to the acquired object-related information, and perform phase connection with respect to the phase difference image with reference to the read-out shape profile.

An optical measuring device includes: a laser light source that emits first light having a first wavelength; an image capturing unit that emits second light having a second wavelength different from the first wavelength; a separating unit that receives the first light and the second light to direct the first light and the second light toward an object to be measured, and receives reflected light from the object to be measured to separate the reflected light into first reflected light based on the first light and second reflected light based on the second light; a light receiving element that receives the first reflected light separated by the separating unit; and a calculating unit that calculates a yawing angle and a pitching angle of the object to be measured based on a light receiving result of the light receiving element, in which the image capturing unit captures an image of the object to be measured by receiving the second reflected light separated by the separating unit, and the calculating unit calculates a rolling angle of the object to be measured based on an image capturing result acquired by the image capturing unit.

An organic light-emitting diode (OLED) deposition system has a workpiece transport system configured to position a workpiece within the OLED deposition system under vacuum conditions, a deposition chamber configured to deposit a first layer of organic material onto the workpiece, a metrology system having one or more sensors measure of the workpiece after deposition in the deposition chamber, and a control system to control a deposition of the layer of organic material onto the workpiece. The metrology system includes a digital holographic microscope positioned to receive light from the workpiece and generate a thickness profile measurement of a layer on the workpiece. The control system is configured to adjust processing of a subsequent workpiece at the deposition chamber or adjust processing of the workpiece at a subsequent deposition chamber based on the thickness profile.

A distance measurement device includes: a signal acquisition unit to acquire an electric signal based on interference light from an optical sensor device that splits sweep light having a periodically changing frequency into reference light and irradiation light to be emitted toward an object to be measured, irradiates the object with the irradiation light, generates interference light by causing the reference light to interfere with reflected light that is the irradiation light reflected by the object, and generates the electric signal based on the generated interference light; a frequency calculation unit to calculate, on the basis of the electric signal based on the interference light, a peak frequency of the electric signal using LASSO regression; a distance measurement unit to measure, on the basis of the peak frequency, a distance from a predetermined reference point to the object; and a distance output unit to output distance information indicating the distance.

A shape of an object is measured with a high degree of accuracy. A shape measurement system comprises: a distance measuring head for irradiating an object with light and receiving light reflected from the object; a distance measuring device for generating a distance detection waveform on the basis of the reflected light; and a control device for analyzing the distance detection waveform and calculating a measured distance value to the object. The shape measurement system is characterized in that the control device calculates a feature amount of the distance detection waveform and performs at least one of a process of correcting an error in the measured distance value by substituting the feature amount into a correction formula and a process of performing a confidence weighting of an error in the measured distance value by substituting the feature amount into a confidence weighting formula.