Abstract: To detect whether a substrate is in a focal plane of a scatterometer, a cross-sectional area of radiation above a certain intensity value is detected both in front of and behind a back focal plane of the optical system of the scatterometer. The detection positions in front of and behind the back focal plane should desirably be equidistant from the back focal plane along the path of the radiation redirected from the substrate so that a simple comparison may determine whether the substrate is in the focal plane of the scatterometer.

Abstract: Measurement of a profile of a scatterometry object on top of one or more product layers on a substrate is disclosed. To prevent an unknown parameters of one or more product layers having an effect on the measurement of the object profile, the thickness of the one or more product layers is measured prior to measuring the profile of the scatterometry object on the layer(s). In an embodiment, each of a plurality of product layers is measured as it is exposed so that only the degree of freedom of the most recently exposed product layer is unknown at each measurement step. When each of a plurality of product layers has been measured, and a scatterometry object is placed at the top of the layers, only the degrees of freedom of that scatterometry object should be unknown and only the profile of the object should need to be measured.

Abstract: A crystal optical material is illuminated at a wavelength of light that does not ionize the crystal optical material. Birefringence is measured between a plurality of voxels within the crystal optical material having spatial dimensions small enough to distinguish optical propagations of the light encountering boundary regions between subgrains of the crystal mosaic from optical propagations of the light through the subgrains themselves. The measured birefringence is evaluated for quantifying a characteristic of the crystal matrix. Metrics describing the crystal matrix are associated with performance of the crystal optical material.

Abstract: To effectively reduce a measurement error in a parameter indicating a state of spectroscopic polarization generated by variations in retardation of a retarder due to a temperature change or other factors, while holding a variety of properties of a channeled spectroscopic polarimeter. By noting that reference phase functions ?1(?) and ?2(?) are obtained by solving an equation from each vibration component contained in a channeled spectrum P(?), the reference phase functions ?1(?) and ?2(?) are calibrated concurrently with measurement of spectrometric Stokes parameters S0(?), S1(?), S2(?), and S3(?).

Abstract: A method of measuring dimensions for an optical system to measure the critical dimension of a sample object according to this aspect of the present invention includes the steps of preparing a plurality of standard objects, selecting a predetermined focus metric algorithm, performing an analyzing process on each standard object to generate a plurality of focus metric distributions using the predetermined focus metric algorithm, analyzing the focus metric distributions to determine a target order, generating a reference relation, acquiring a measured characteristic value from the sample object, and determining the critical dimension of the sample object based on the measured characteristic value and the reference relation. Each standard object has a grating-shaped standard pattern with a predetermined pitch and line width. The focus metric algorithm is a gradient energy method, a Laplacian method, a standard deviation method, or a contrast method.

Abstract: A method, apparatus, and computer program product for identifying features in a sample by analyzing Mueller matrices to calculate an average degree of polarization, a weighted average degree of polarization, a degree of polarization map, a degree of polarization surface. Also, a method, apparatus, and computer program product for identifying features in a sample by analyzing Mueller matrices to calculate depolarization relative to a retardance axis and/or a diattentuation axis, and to calculate a ratio of diattenuation to polarizance or ratios of row and column magnitudes. Also, a method for retinal polarimetry, including a non-depolarizing light tube configured for insertion into the eye.

Abstract: The present invention provides a method of determining certain propeller parameters for a boat propeller that has a hub, a central axis and a plurality of propeller blades attached to the hub. The method includes providing a laser displacement sensor in proximity to the propeller. The laser displacement sensor has a laser head that generates a laser beam. The laser displacement sensor is used to measure the distance from the laser head to the propeller. The laser head is moved and the laser again measures the distance from the laser head to the propeller after the laser head is moved in relation to the propeller. The movement can be along either or both of the two axes including a first axis that is a linear axis and a second axis that is curved. The method includes computing a selected parameter or parameters by using the measurements that are obtained, the parameters being selected from a group that includes pitch, rake and squareness.

Abstract: Apparatus and techniques for automated optical inspection (AOI) utilizing image scanning modules with multiple objectives for each camera are provided. A scanning mechanism includes optical components to sequentially steer optical signals from each of the multiple objectives to the corresponding camera.

Abstract: A localized plasmon resonance sensor for detecting a change in optical constant uses a structure including metal. In a response spectrum with respect to light incident on the structure, there are at least two resonance peaks including at least one resonance peak shifted to a longer wavelength side and at least another peak shifted to a shorter wavelength side, by the change in optical constant.

Abstract: A system for measuring light absorption levels includes a light source providing a light beam and a container for a liquid. The container includes an opening to provide access to the liquid. A prism is disposed over the opening and is operable to direct at least a first portion of the light beam toward the opening to the liquid such that the at least a portion of the first portion of the light beam is reflected back from the liquid forming an attenuated beam. A detector is operable to measure at least one of a portion of the attenuated beam and a second portion of the light beam. The detector is operable to produce at least one of a liquid measurement signal and a reference signal. A device is operable to compute a ratio of the liquid measurement signal to the reference signal to determine a signal ratio.

Abstract: Apparatus for inspecting a surface of a sample, including a detector and folding optics. The folding optics are configured to receive radiation arising from a first region of the surface and from a second region of the surface. The first region and the second region have a first spatial relationship with respect to each other. The folding optics form from the radiation a first image of the first region and a second image of the second region on the detector, wherein the first image is a linear transformation of the first region and the second image is the linear transformation of the second region. The first image and the second image have a second spatial relationship, different from the linear transformation of the first spatial relationship, with respect to each other.

Abstract: A system and method for inspection a substrate for various defects is herein disclosed. Polarizing filters are used to improve the contrast of polarization dependent defects such as defocus and exposure defects, while retaining the same sensitivity to polarization independent defects, such as pits, voids, cracks, chips and particles.

Abstract: A method for testing a polarization state of polarized light includes forming a test photosensitive film on a test wafer, the test wafer having a flat surface and a grid pattern in which reflectance changes depending on a polarization direction of the polarized light, exposing the test photosensitive film to the polarized light, measuring a change of a property of the test photosensitive film caused by the polarized light, and determining a polarization state of the polarized light, based on the change.

Abstract: The profile of a single feature formed on a wafer can be determined by obtaining an optical signature of the single feature using a beam of light focused on the single feature. The obtained optical signature can then be compared to a set of simulated optical signatures, where each simulated optical signature corresponds to a hypothetical profile of the single feature and is modeled based on the hypothetical profile.

Abstract: It is possible to detect with high precision a plurality of types of nonuniformity defects that occur in patterns formed on the surface of an examination object. A device (10) for examination of nonuniformity defects that has a light source (12) for emitting light to a photomask 50 whose surface is provided with a repeating pattern (51) in which unit patterns (53) are arrayed in a regular fashion, and a photodetector (13) for photodetecting and converting into photodetection data scattered light from the photomask, so that the photodetection data is observed to detect nonuniformity defects that have occurred in the repeating pattern, in the device further having a wavelength filter (14) for selecting and extracting one or a plurality of desired wavelength bands from the light of a plurality of wavelength bands, wherein nonuniformity defects of the repeating pattern are detected using the selected and extracted light of the wavelength band.

Abstract: The present invention relates to a random type recognition object for an identification apparatus wherein identification particles are distributed irregularly within a 3D shape and a positional value and a characteristic value of the identification particles distributed within the 3D shape in one or plural directions are recognized by separate recognition means, and an identification apparatus and method using a random type recognition object whose reproduction is impossible.

Abstract: An optical sensor device includes a photoconductor structure having first and second partial members (16, 18) and a coupling surface (20) for coupling the optical sensor device to an opposing counter surface of a pane (22), particularly a windscreen of a motor vehicle. The optical sensor device further includes an optical transmitter (10) coupling a beam of rays into the first partial member (16), an optical receiver (12) receiveing a beam of rays emerging from the second partial member (18), and a printed circuit board (14) arranged parallel to the coupling surface (20). The transmitter (10) and the receiver (12) are arranged on the printed circuit board (14). The photoconductor structure is designed so that the central ray (28) of the transmitter (10) enters into the first partial member (16) perpendicularly to the coupling surface (20) and emerges from the second partial member (18) perpendicularly to the coupling surface (20).

Abstract: An apparatus and method for detecting defects in a transparent substrate by simultaneously using a combination of bright field and dark field light sources for illuminating the substrate. The apparatus is capable of detecting both inclusions and surface defects simultaneously while the substrate is in motion, simplifying the characterization of substrates in a manufacturing setting.

Abstract: A surface inspection system, as well as related components and methods, are provided. The surface inspection system includes a beam source subsystem, a beam scanning subsystem, a workpiece movement subsystem, an optical collection and detection subsystem, and a processing subsystem. The system features a variable scan speed beam scanning subsystem, preferably using an acousto-optic deflector, with beam compensation, so that variable scanning speeds can be achieved. Also included are methods and systems for improving the signal to noise ratio by use of scatter reducing complements, and a system and method for selectively and repeatedly scanning a region of interest on the surface in order to provide additional observations of the region of interest.

Abstract: Methods are provided for detecting compression wood, blue stain, or pitch in lumber. A light beam is projected towards the wood sample. Line or area cameras acquire images of light that is reflected from the wood sample. Based on the intensity of the reflected light at one or more locations on the wood sample, compression wood, blue stain, or pitch may be detected.