Abstract: In order to monitor the subsoil of the earth under a target zone, seismic waves coming from an identified mobile noise source are recorded by means of at least one pair of sensors disposed on either side of the target zone, time periods are selected corresponding to the alignments of the pairs of sensors with the noise source, a seismogram of the target zone is reconstructed by interferometry based on the recorded seismic waves and on the selected time periods and an image of the subsoil of the target zone is generated using the seismogram.

Abstract: The application relates to a cleaning system configured for cleaning of cavities filled with a liquid, including fragmentation, debridement, material removal, irrigation, disinfection, and decontamination. The cleaning system includes an electromagnetic radiation system and a liquid. A treatment handpiece irradiates the liquid within a cavity with a radiation beam, producing a first vapor bubble using first pulse, and, at a different location, a second vapor bubble using a second pulse. The pulse repetition time is adjusted to ensure efficacy, for example such that an onset time of the second vapor bubble is within the first contraction phase of the first vapor bubble, when the first vapor bubble has contracted from its maximal volume to a size in a range from about 0.7 to about 0.1 of the maximal volume.

Abstract: A swept-source optical coherence tomography (SS-OCT) apparatus includes a plurality of wavelength-tunable light sources. The SS-OCT apparatus includes a first optical coupler configured to receive an output from each of the plurality of wavelength-tunable light sources. The optical coupler is configured to split the received output from the plurality of wavelength-tunable light sources into a reference optical path and a sample optical path. The sample optical path is configured to illuminate a sample. The SS-OCT apparatus includes a second optical coupler configured to receive return optical signals from the reference optical path and the sample optical path, and to output an optical interference signal. The SS-OCT apparatus includes a detector configured to detect the optical interference signal; and a controller configured to receive an electrical signal based on the detected optical interference signal. The controller is configured to generate a depth profile of the sample using compressed sensing.

Abstract: A module accommodates multiple superluminescent light emitting diodes, SLEDs, 12r, 12g and 12b. The SLEDs are arranged in an enclosure and output respective light beams to propagate into free space within the enclosure. The individual light beams from the SLED sources are combined into a single beam path within the enclosure using beam combiners 40r-g, 40rg-b. Each beam combiner is realized as a planar optical element, the back side of which is arranged to receive a SLED beam and route it through the optical element to the front side where it is combined with another SLED beam that is incident on and reflected by the front side. The free-space propagating combined beam is output from the module via an optical fiber 42 (or through a window).

Abstract: An optical seismic surveying system including, a multibeam laser source including a plurality of laser-sources, a Diffractive-Optical-Element (DOE), an imager and a processor. The laser-sources direct respective laser-beams toward a single common focal point. The DOE is located at a single common focal point and configured to split each laser-beam into a plurality of laser-beams, toward an instantaneous area of interest. The laser-beams impinging on the instantaneous area of interest produce a laser spot assemblage including a plurality of laser spots. The imager acquires a plurality of defocused images of speckle patterns produced by diffused reflections of the laser spots. The speckle pattern correspond to a respective laser spot and thus to a respective sensing point in the instantaneous area of interest.

Abstract: Disclosed is a self-coherent receiver based on polarization-independent delay interferometers, relating to a technical field of optical communication, including a first beam splitter, a first circulator, a second circulator, a first polarization-independent delay interferometer, a second polarization-independent delay interferometer, a first balanced detector, a second balanced detector and an electrical signal processing module.

Abstract: Embodiments of the disclosure are drawn to apparatuses and methods for a rotating optical reflector. Optical systems may have a limited field of view, and so in order to expand the area that the optical system collects data from, the field of view of the optical system may be scanned across a target area. The present disclosure is directed to a rotating optical reflector, which includes a transmissive layer which refracts light onto a reflective layer, which has a normal which is not parallel to the axis about which the optical reflector is rotated. The optical reflector may be both statically and dynamically balanced, which may allow an increased size of the optical reflector, which in turn may increase the aperture of an optical system (e.g., a lidar system) using the rotating optical reflector.

Abstract: A method for treating a treatment site within or adjacent to a vessel wall or a heart valve, includes the steps of (i) generating light energy with a light source; (ii) positioning a balloon substantially adjacent to the treatment site, the balloon having a balloon wall that defines a balloon interior that receives a balloon fluid; (iii) receiving the light energy from the light source with a light guide at a guide proximal end; (iv) guiding the light energy with the light guide in a first direction from the guide proximal end toward a guide distal end that is positioned within the balloon interior; and (v) optically analyzing with an optical analyzer assembly light energy from the light guide, wherein the light energy that is analyzed moves in a second direction that is opposite the first direction.

Abstract: A method and related system for measuring a surface of a substrate including at least one structure using low coherence optical interferometry, the method being implemented with a system having an interferometric device, a light source, an imaging sensor, and a processing module, the method including: - acquiring, with the imaging sensor, an interferometric signal formed by the interferometric device between a reference beam and a measurement beam reflected by the surface at a plurality of measurement points in a field of view; the following steps being carried out by the processing module: classifying, by a learning technique, the acquired interferometric signals according to a plurality of classes, each class being associated with a reference interferometric signal representative of a typical structure; and analysing the interferometric signals to derive information on the structure at the measurement points, as a function of the class of each interferometric signal.

Abstract: A device and a method for determining an ocular aberration of at least one eye of a user are disclosed. The device contains a wavefront sensing unit for measuring at least one optical wavefront with at least one light beam, from which an ocular aberration of the at least one eye of the user is determined. The device further contains at least one diffractive element for generating multiple diffraction orders in the light beam in two meridians in a manner that the multiple diffraction orders are spatially separated on the wavefront sensing unit and in the eye of the user. The device and the method allow generating an ocular defocus map in a one-shot assessment in real-time, especially by employing an automated measurement of the ocular aberrations with regard to different eccentricities of the eye of the user in two meridians.

Abstract: Methods of determining at least one parameter of an irradiation device of an apparatus for additively manufacturing three-dimensional objects may include generating an energy beam and guiding the energy beam across a structured test surface, generating a signal by detecting radiation that is emitted from the test surface, and determining the at least one parameter based on a frequency spectrum of the signal.

Abstract: A measurement system is provided for use in optical metrology measurements. The measurement system comprises a control system which processes raw measured data indicative of spectral interferometric signals measured on a sample in response to illuminating electromagnetic field incident onto a top portion of the sample and comprising at least one spectral range to which said sample is substantially not absorbing.

Abstract: A method for operating an optical modulator includes receiving a narrowband radio frequency (“RF”) signal. The method further including, responsive to receiving the narrowband RF signal, modulating the narrowband RF signal using a double sideband suppressed carrier (“DSBSC”) modulation scheme to generate a DSBSC optical signal. The method further including transmitting the DSBSC optical signal to an optical transmitter.

Abstract: Global and local alignment energies are used in an image contrast metric. The image contrast metric can be used to find optical targets. Some pixels from a gradient magnitude image and a context range image from an optical image can be used to determine the image contrast metric. A heatmap from the image contrast metrics across part of a wafer can then be used to make a list of targets. Upper and lower confidence values can be applied to rank the available targets.

Abstract: Disclosed is a fluorescent fundus camera which is one kind of ophthalmological diagnostic equipment, using a blue excitation light beam when a contrast medium appears in the retinal vessels. When an abnormal blood vessel is present, the contrast medium leaks into the retina or appears as color in tissues surrounding the retina, and the presence of damage to the retina and the appearance of abnormal neovascularization can be found.

Abstract: A microelectromechanical (MEMS) interferometer is provided. The MEMS interferometer includes a pair of movable mirrors that are positioned along perpendicular axes, wherein each of the pair of movable mirrors is coupled to a mechanism. The mechanism includes an electrostatic actuator driving a displacement amplification mechanism, and the displacement amplification mechanism driving each of the pair of the movable mirrors. The MEMS interferometer includes a beam splitter that is positioned at an intersection of the perpendicular axes extending through each movable mirror and the beam splitter. The MEMS interferometer also includes a metasurface microbolometer placed in line with the beam splitter to measure an intensity of a recombined beam from the pair of movable mirrors.

Abstract: A system includes first and second radiation sources, first and second detectors, a signal digitizer, a controller, and an analyzer. The first and second radiation sources generate respective first and second beams of radiation to irradiate a target. The first beam and second beams each include a first wavelength operated at a first modulation frequency and a second wavelength operated at a second modulation frequency. The first and second detectors each include a photo-sensitive element that generate first or second detection signals, a Faraday shielding enclosure, a signal amplifier, and a frequency mixer to frequency-adjust the first or second detection signals. The controller provides timing information to inform an activation scheme of the first and second radiation sources and corresponding radiation detection events at the first and second detectors. The analyzer analyzes the first and second detection signals and determines at least amplitude and phase information of the scattered radiation.

Abstract: Disclosed is a visual imaging device based on PS-OCT for early demineralization and caries of dental hard tissues, comprising a laser light source for emitting a laser light, a coupler for receiving and dividing the laser light emitted by the laser light source into a reference laser light and a detection laser light; wherein the reference laser light backtracking to the coupler and the detection laser light backtracking to the coupler are coupled and then passed through a transmission grating and a convex lens to input as an optical signal into a linear CCD detector for converting the optical signal into an electrical signal which is then input to a computer control system and collected by a built-in capture card; and the computer is configured to perform a three-dimensional reconstruction of an image and perform two-dimensional cross-section image analysis; and the computer control system is connected to the scanning galvanometer to control a vibration of the scanning galvanometer.

Abstract: A fast measurement method for micro-nano deep groove structure based on white light interference, including: establishing a white light interference system, using the white light interference system to measure the structure of the groove, the CCD camera collects and obtains multiple groups of groove interferograms and the serial number corresponding to each groove interferogram in each group; processing each group of groove interferograms of the groove sample to obtain the maximum contrast of each group of groove interferograms and the 3D reconstruction diagram of the local structure; extracting the interface reconstruction diagram in the 3D reconstruction diagram of the local structure according to each group of the groove interferograms; after splicing the interface reconstruction diagrams corresponding to all groups of groove interferograms, obtaining a 3D structural reconstruction diagram of the groove sample, and measuring the depth and width of the groove sample according to the 3D structural reconstruc

Abstract: Automated and objective methods for quantifying a retinal characteristic include segmenting an optical coherence tomography retinal image into a plurality of layered retinal regions, and quantifying the retinal characteristic for each region as normalized to a range defined by the characteristic value in the vitreous region and in the retinal pigment epithelium region. Such methods are useful for detecting occult ocular pathology, diagnosing ocular pathology, reducing age-bias in OCT image analysis, and monitoring efficacy ocular/retinal disease therapies.

Abstract: A method for remediating developmentally delayed plants within a field of crops using at least one work vehicle during a field operation. The method comprises identifying delayed plants within the field with a sensor on the work vehicle and generating, with a processor, location data associated with the location of the delayed plant with the field. Upon arriving at the location of the delayed plant with the work vehicle, the delayed plant is remediated.

Abstract: A method for measuring a surface of an object including at least one structure using low coherence optical interferometry, the method including the steps of acquiring an interferometric signal at a plurality of measurement points in a field of view and, for at least one measurement point, attributing the interferometric signal acquired to a class of interferometric signals from a plurality of classes, each of the classes being associated with a reference interferometric signal representative of a typical structure; and analysing the interferometric signal to derive therefrom an item of information on the structure at the measurement point, as a function of its class.

Abstract: A method for determining geometrical parameters of a soft contact lens comprises the steps of providing an OCT imaging device comprising an OCT light source; providing a soft contact lens arranging the soft contact lens relative to the OCT imaging device so light coming from the OCT light source impinges on the back surface of the soft contact lens; generating a three-dimensional OCT image of the soft contact lens; from the three-dimensional OCT image determining a plurality of edge points located on the edge of the soft contact lens, connecting adjacent ones of the edge points by individual straight lines; summing up the lengths of all individual straight lines to a length U of the approximated circumference of the soft contact lens; from the length U determining a diameter D of the lens according to D=U/?.

Abstract: The present disclosure provides an OCT imaging system to reduce or eliminate frequency-domain aliasing artifacts. The frequency is shifted using a carrier frequency to define a sampling range substantially centered on the carrier frequency. An image of the sample is generated from a displayed imaging range that consists of a subset of the frequencies within the sampling range. Furthermore, the system may be configured to determine the carrier frequency such that a Nyquist frequency corresponding to the shifted frequency is extended beyond either an upper or a lower bound of an OCT quality envelope corresponding to the first portion of light. Additionally, the carrier frequency may be determined such that a lower bound of the OCT quality envelope is greater or less than a zero-frequency DC limit.

Abstract: A microscopic imaging method of phase contrast (PC) and differential interference contrast (DIC) based on the transport of intensity equation (TIE) includes capturing three intensity images along the optical axis; solving the TIE by deconvolution to obtain the quantitative phase; obtaining the intensity image under the DIC imaging mode according to the DIC imaging principle; and obtaining the corresponding phase image of PC imaging mode according to the PC imaging principle. The method can endow the bright-field microscope with the ability to realize PC and DIC imaging without complex modification of the traditional bright-field microscope. In addition, it has the same imaging performance as the phase contrast microscope and differential interference contrast microscope, which are expensive, complex-structure, and has strict environmental conditions.

Abstract: An ophthalmic imaging system including an ocular lens and an optical coherence tomography (OCT) imaging module is provided. The OCT imaging module is able to image both retina and anterior segment of eyes by switching a lens group into and out of the OCT light path. The OCT imaging module includes a retina imaging mode and an anterior segment imaging mode. In the retina imaging mode, there exists an intermediate image plane located between the ocular lens and the OCT imaging module. From the retina imaging mode, anterior segment imaging is achieved by inserting a switching lens group into the optical path inside the OCT imaging module or replacing the whole OCT imaging module of the retina mode, wherein, after the insertion, there exist a new intermediate image plane located inside the OCT imaging module and a conjugate of the entrance pupil of the OCT imaging module located between the ocular lens and the OCT imaging module.

Abstract: A method for non-contact modal analysis uses an optical sensing device such as a video camera. Unlike traditional modal analysis, requiring accelerometers or force sensors to measure the modal characteristics of a structure, the inventive system uses pixel displacement measurements from the optical sensor to characterize the modal properties of the device under test. The input or reference signal is measured by an independent data acquisition system and is synchronized with the response motion captured in video recordings.

Abstract: An OCT imaging system may include an OCT light source operable to emit an OCT light beam, and a beam splitter operable to split the OCT light beam into a sample beam, transferred to a sample arm waveguide, and a reference beam, transferred to a reference arm waveguide. The sample arm waveguide and the reference arm waveguide may be coupled together within a cladding, wherein the cladding improves a calibration of a generated OCT image by fixing axial movement of the sample arm and reference arm waveguides relative to one another. By routing long reference and sample arm waveguide fibers together in the OCT system using a sheath/cladding, OCT image offset due to asymmetrical fiber stretching can be minimized or eliminated.

Abstract: Examples of the disclosure relate to an apparatus (101), a wearable electronic device and an optical arrangement for optical coherence tomography. The apparatus comprises an optical coherence tomography system (103) and an optical arrangement (105). The optical arrangement comprises at least one means for beam shaping (109) configured to shape a beam of light from the optical coherence tomography system. The optical arrangement also comprises at least one mirror (111) positioned so that light from the means for beam shaping is incident on the at least one mirror. The at least one mirror is configured to move in at least one direction relative to the optical coherence tomography system.

Abstract: A target image to be corrected is generated by arranging partial images acquired by scanning a tissue of a living body with light and temporally continuously receiving the light from the tissue. A processor of a medical image processing device performs detecting position shift amounts, acquiring a component, and correcting. In the process of detecting position shift amounts, the processor detects the position shift amounts between the partial images (S3). In the process of acquiring, the processor acquires an assumed result of at least one of a component in the position shift amount caused by movement of the tissue, and a component in the position shift amount caused by a shape of the tissue (S4). In the process of correcting, the processor corrects a position of each of the partial images based on the component in the position shift amount (S7).

Abstract: There is provided an imaging device (100) for imaging a target, the imaging device (100) comprising a Scheimpflug imaging system (102) and an Optical Coherence Tomography, OCT, imaging system (104), where the Scheimpflug imaging system (102) comprises a camera (112) and a lens system (108), and the OCT imaging system (104) comprises an imaging optical element and a detector (122). The imaging device (100) further comprises a light source (106) adapted to provide a light beam suitable for operation of the Scheimpflug imaging system (102) and the OCT imaging system (104). The lens system (108) of the Scheimpflug imaging (102) system is configured to provide an adjustable focal length.

Abstract: Embodiments of systems and methods for measuring a surface topography of a semiconductor chip are disclosed. In an example, a method for measuring a surface topography of a semiconductor chip is disclosed. A plurality of interference signals and a plurality of spectrum signals are received by at least one processor. Each of the interference signals and spectrum signals corresponds to a respective one of a plurality of positions on a surface of the semiconductor chip. The spectrum signals are classified by the at least one processor into a plurality of categories using a model. Each of the categories corresponds to a region having a same material on the surface of the semiconductor chip. A surface height offset between a surface baseline and at least one of the categories is determined by the at least one processor based, at least in part, on a calibration signal associated with the region corresponding to the at least one of the categories.

Abstract: A measuring device determines a distance between a processing head for a laser processing system configured to process a workpiece with a laser beam and the workpiece. The measuring device includes an optical coherence tomograph to measure a distance between the processing head and workpiece. In the optical coherence tomograph, measuring light generated by a measuring light source and reflected by the workpiece interferes with measuring light reflected in a reference arm with two or more reference stages. The stages include a first reference stage configured such that the measuring light reflected therein travels a first optical path length, and a second reference stage configured such that the measuring light reflected therein travels a second optical path length different from the first length, wherein the measuring light reflected by the workpiece interferes with reflected measuring light of the first reference stage and reflected measuring light of the second reference stage.

Abstract: An apparatus for oral imaging has a light source energizable to generate a light frequency signal ranging from a minimum to a maximum frequency. An image acquisition apparatus scans the generated light frequency signal to successive positions on a sample surface and to combine a returned signal from each successive position with the generated light frequency signal. The image acquisition apparatus has a detector that obtains a beat frequency signal from the combined returned signal and the generated light frequency signal. A processor that is in signal communication with the detector generates a processed beat signal from the combined signals, wherein the processed beat signal is indicative of the distance from the tunable laser source to the sample surface at the corresponding position. A display is in signal communication with the processor and is energizable to display distance data according to the processed beat signal for each scanned position.

Abstract: An analysis apparatus includes an acquisition part that acquires a plurality of interference images of the object to be measured from the interference measurement apparatus, a calculation part that calculates a sine wave component and a cosine wave component of an interference signal for each pixel in the plurality of interference images, respectively, an error detection part that detects an error between a first Lissajous figure constructed on the basis of the sine wave component and the cosine wave component for each pixel and an ideal second Lissajous figure, a correction part that corrects the sine wave component and the cosine wave component for each pixel on the basis of the error, and a geometry calculation part that calculates surface geometry of the object to be measured on the basis of the corrected sine wave component and cosine wave component.

Abstract: Fourier Transformation Spectrometer, FT Spectrometer, comprising: A double beam interferometer, comprising: At least one beam splitter unit (622; 623; 624, 625, 626, 627; 636; 673, 674, 675) for splitting an incident light beam (EB) of a spatially expanded object into a first partial beam (TB1) and a second partial beam (TB2); at least a first beam deflection unit (630; 641; 651; 661; 697) designed to deflect the first partial beam (TB1) at least a first and a second time, wherein the second beam deflection unit (630) is designed to also deflect the second partial beam (TB2) at least at first and a second time; or the double beam interferometer comprises a second beam deflection unit (642; 652; 662) designed to deflect the second partial beam (TB2) at least a first and a second time, wherein the beam deflection unit is also designed to at least partially spatially overlay the first partial beam (TB1) and the second partial beam (TB2), and the respectively first and second deflection of the first partial beam

Abstract: An analysis apparatus includes an acquisition part that acquires a plurality of interference images based on lights having a plurality of different wavelengths from an interference measurement apparatus, a removing part that outputs an interference component by removing a non-interference component included in an interference signal for each pixel in the plurality of the interference images, a conversion part that generates an analysis signal by performing a Hilbert transformation on the interference component, and a calculation part that calculates a distance between a reference surface and a surface of an object to be measured by specifying a phase gradient of a wavelength of light radiated onto the reference surface and the surface of the object to be measured on the basis of the interference component and the analysis signal.

Abstract: Aspects relate to reconstructing phase images from brightfield images at multiple focal planes using machine learning techniques. A machine learning model may be trained using a training data set comprised of matched sets of images, each matched set of images comprising a plurality of brightfield images at different focal planes and, optionally, a corresponding ground truth phase image. An initial training data set may include images selected based on image views of a specimen that are substantially free of undesired visual artifacts such as dust. The brightfield images of the training data set can then be modified based on simulating at least one visual artifact, generating an enhanced training data set for use in training the model. Output of the machine learning model may be compared to the ground truth phase images to train the model. The trained model may be used to generate phase images from input data sets.

Abstract: An apparatus includes a wavelength-tunable laser and an electronic controller. The electronic controller is configured to control the wavelength-tunable laser such that an output wavelength of the wavelength-tunable laser performs a zigzag in time. The wavelength-tunable laser is capable of rapidly and densely scanning wavelengths across a broad spectral range.

Abstract: Methods and apparatus are presented for obtaining high-resolution 3-D images of a sample over a range of wavelengths, optionally with polarisation-sensitive detection. In preferred embodiments a spectral domain OCT apparatus is used to sample the complex field of light reflected or scattered from a sample, providing full range imaging. In certain embodiments structured illumination is utilised to provide enhanced lateral resolution. In certain embodiments the resolution or depth of field of images is enhanced by digital refocusing or digital correction of aberrations in the sample. Individual sample volumes are imaged using single shot techniques, and larger volumes can be imaged by stitching together images of adjacent volumes.

Abstract: Retinal imaging systems and related methods employ a user specific approach for controlling the reference arm length in an optical coherence tomography (OCT) imaging device. A method includes restraining a user's head relative to an OCT imaging device. A reference arm length adjustment module is controlled to vary a reference arm length to search a user specific range of reference arm lengths to identify a reference arm length for which the OCT image detector produces an OCT signal corresponding to the retina of the user. The user specific range of reference arm lengths covers a smaller range of reference arm lengths than a reference arm length adjustment range of the reference arm length adjustment module.

Abstract: Embodiments of systems for classifying interference signals are disclosed. In an example, a system for classifying interference signals includes an interferometer including a light source and a detector, and at least one processor. The interferometer is configured to provide a plurality of interference signals each corresponding to a respective one of a plurality of positions on a surface of a semiconductor chip. A spectrum of the light source is greater than a spectrum of white light. The at least one processor is configured to classify the interference signals into a plurality of categories using a model. Each of the categories corresponds to a region having a same material on the surface of the semiconductor chip.

Abstract: A device and method for performing reflectivity measurements at a distance by receiving two or more reflected signals (using two or more different wavelength sweeps) and calculating ratios of the two (or more) received reflected signals, for the purpose of determining the composition of a material or surface at a distance.

Abstract: The present invention relates to a method for the non-invasive optical characterization of a heterogeneous medium, comprising: a step of illuminating, by means of a series of incident light waves, a given field of view of the heterogeneous medium, positioned in a focal plane of a microscope objective (30); a step of determining a first distortion matrix (Dur, Drr) in an observation basis defined between a conjugate plane of the focal plane (FP) and an observation plane, said first distortion matrix corresponding, in a correction basis defined between a conjugate plane of the focal plane and an aberration correction plane, to the term-by-term matrix product of a first reflection matrix (Rur) of the field of view, determined in the correction basis, with the phase conjugate matrix of a reference reflection matrix, defined for a model medium, in said correction basis; and a step of determining, from the first distortion matrix, at least one mapping of a physical parameter of the heterogeneous medium.

Abstract: The invention relates to an OCT system, comprising: an OCT light source for emitting OCT light into an object beam path and a reference beam path; and a detector for capturing an interference signal produced from the object beam path and the reference beam path. A wavelength-dependent beamsplitter is arranged in the OCT beam path such that a first spectral partial beam is guided along a longer path and a second spectral partial beam is guided along a shorter path. The invention further relates to a corresponding OCT method. Two measurement regions separated from each other can be sensed by means of the OCT system according to the invention.

Abstract: Semiconductor device metrology including creating a time-domain representation of wavelength-domain measurement data of light reflected by a patterned structure of a semiconductor device, selecting an earlier-in-time portion of the time-domain representation that excludes a later-in-time portion of the time-domain representation, and determining one or more measurements of one or more parameters of interest of the patterned structure by performing model-based processing using the earlier-in-time portion of the time-domain representation.

Abstract: A method for imaging a sample using a microscope includes recording a first image of the sample, the first image being represented by image data. Sample information is extracted from the first image by analyzing the image data using an analyzer. At least a part of the sample is scanned with a light beam while modulating the light beam based on the extracted sample information. A second image of the sample is recorded during and/or after scanning the sample with the modulated light beam.

Abstract: An adaptive focusing system including an optics module, an optics module height positioner (OMHP), a position sensor operative to generate a position output indicating a height of the optics module, a predictive height estimator operative to generate an estimated height value of a sample at each site of a plurality of sites, and generate a desired optics module height output for each of the sites, a regulator operative to generate, at least partially based on the desired optics module height output and a known height of the optics module, a sequence of optics module height control instructions for the plurality of sites, a driver operative to provide a sequence of control outputs to the OMHP and a model predictive controller (MPC) operative to monitor differences between a reported height of the optics module and an MPC-expected height of the optics module, thereby to generate system amelioration values.

Abstract: A height detection apparatus successively changes the brightness of white light from a first level to a second level in accordance with a position of a Z stage and captures an image of interference light while moving a two-beam interference objective lens relative to a paste film in an optical axis direction, detects, as a focus position, a position of the Z stage where the intensity of interference light is highest in a period during which the brightness of white light is set to the first or second level, for each pixel of the captured image, and obtains the height of the paste film based on a detection result.

Abstract: Method and system for determining separation distance between an object and a processing or measuring tool involve generating a measurement beam of low coherence optical radiation, leading the measurement beam towards the object and the reflected measurement beam towards an optical interferometric sensor assembly in a first direction of incidence, generating a reference beam of low coherence optical radiation, and leading the reference beam towards the optical interferometric sensor assembly in a second direction of incidence, superimposing the measurement and reference beams on a common region of incidence, detecting position of a pattern of interference fringes between the measurement and reference beams on the region of incidence, and determining difference in optical length between a measurement optical path and a reference optical path on position of the pattern of interference fringes along an illumination axis to determine current separation distance between the processing or measuring tool and the obj