Abstract: A device and a method for high-speed linear polarization imaging of a scene are disclosed. The device comprises a polarization modulator for modulating the polarization of light emitted from the scene in order to obtain at least three linear polarization states of the light. The polarization modulator comprises a polarizer, a first polarization rotation block comprising a fixed quarter-wave plate and a first liquid crystal operating as a quarter-wave plate, and a second polarization rotation block comprising a second liquid crystal operating as a half-wave plate. Each of the first and second liquid crystals are switchable between two states, thereby providing the at least three polarization states to the polarization modulator. The device further comprises a sensor adapted to capture image frames of the light from the scene at each polarization state of the polarization modulator.

Abstract: Multivariate optical analysis systems employ multivariate optical elements and utilize multivariate optical computing methods to determine information about a product carried by light reflected from or transmitted through the product.

Abstract: Instead of constructing a full multi-dimensional look-up-table as a model to find the critical dimension or other parameters in scatterometry, regression or other optimized estimation methods are employed starting from a “best guess” value of the parameter. Eigenvalues of models that are precalculated may be stored and reused later for other structures having certain common characteristics to save time. The scatterometric data that is used to find the value of the one or more parameter can be limited to those at wavelengths that are less sensitive to the underlying film characteristics. A model for a three-dimensional grating may be constructed by slicing a representative structure into a stack of slabs and creating an array of rectangular blocks to approximate each slab. One dimensional boundary problems may be solved for each block which are then matched to find a two-dimensional solution for the slab.

Abstract: A method for monitoring hydrogen gas and a hydrogen flame wherein an object light having a wavelength of about 309 nm and resulting from two or more laser beams, which have been irradiated to a space to be monitored, is collected and converted to an electronic image, and the electronic image is amplified and converted back to an optical image, thereby imaging a spatial intensity distribution of light at a specific wavelength. A device for monitoring hydrogen gas and a hydrogen flame, which comprises two or more laser beam sources, means for collecting an object light having a wavelength of about 309 nm and resulting from laser beams, which have been irradiated to a space to be monitored, image producing means for converting the object light to an electronic image, amplifying the electronic image, and converting back the amplified electronic image to an optical image, and means for imaging a spatial intensity distribution of light at a specific wavelength.

Abstract: Methods for grading gemstones, apparatus for grading gemstones, and systems that utilize such methods and apparatus are disclosed.

Abstract: Thermally tunable optical sensors are used in sampling tools for analysis of samples from a wellbore. The thermally tunable optical sensors generate a series passbands of wavelength emissions and detect attenuation in a signal thereof. The attenuation detected is processed and used to determine aspects of the samples. Analysis may be completed remotely (outside of the wellbore), within the wellbore (during drilling or otherwise), or as a part of another process such as fluid management, transport and refinement.

Abstract: The present invention discloses a system and method for providing an automated imaging system comprising an illumination source, a phosphorescent imaging target, and an optical imaging sensor for receiving luminance information emitted from the phosphorescent imaging target.

Abstract: It is disclosed a method and an apparatus of determining the distance (D) between a collimator lens (13) and an object. Low-coherence light is emitted from a light source (1) and directed the low-coherence light through a collimator lens (13) to the object. The reflected light from the collimator lens (13) and the object is directed to a beam splitter (4) and split into two beams. Within the reference arm the frequency of the beam is shifted by an acousto-optical modulator (5) to a certain frequency and within the delay arm the time delay of the beam is scanned by a variable delay line (7). After combining both beams in a beam combiner (8), the presence of a frequency component equal to the frequency shift of the acousto-optical modulator (5) is detected and the distance (D) between the collimator lens (13) and the object is calculated.

Abstract: This invention provides a defect inspection method and apparatus that can easily and quickly determine, from among a plurality of inspection conditions, a condition that allows for an inspection with high sensitivity. The inspection apparatus has a variety of optical functions to cover a variety of kinds of defects to be inspected (shape, material, nearby pattern, etc.). For each optical function, grayscale depths of defects that the operator wants detected and of pseudo defects that he or she wants undetected are accumulated for future use, so that conditions conducive to a higher sensitivity and a lower pseudo defect detection rate can be selected efficiently. Conditions that can be selected for optical systems include a bright-field illumination, a dark-field illumination and a bright-/dark-field composite illumination, illumination wavelength bands, polarization filters and spatial filters.

Abstract: A method for determining at least one of distortion and de-focus for an optical imaging system. The method includes determining wavefront aberrations in a pupil plane of the optical imaging system by a wavefront measurement method, determining focus offset measured values in an xy-direction and/or z-direction for one or more different illumination settings by a test pattern measurement method with imaging and comparative evaluation of test patterns for the optical imaging system, and determining values for one or more aberration parameters that relate to the distortion and/or image surface from a prescribed relationship between the determined wavefront aberrations and the determined focus offset measured values.

Abstract: A method, system and apparatus for improving at least one of a) optical interactance measurements, b) optical transmittance measurements and c) optical reflectance measurements. The apparatus has a probe having a body portion and an tip portion. The body portion has a central tubular element having an opening therethrough. The tip portion has a central aperture and a number that is a plurality of ring openings therein. At least some of the plurality of rings are angled with respect to a longitudinal axis of the probe. A plurality of fiber optic bundles corresponds in number at least to the number of ring openings, and at least one fiber optic bundle is arranged at one end of the longitudinal axis for receiving specimen information and at another end of the longitudinal axis connected to a detector for receiving a signal.

Abstract: The present invention features a fiber optic imaging system for generating a customized spectral response comprising (a) an optional optical source for generating optical energy, (b) an optical system for focusing multi spectral optical energy to form a focal surface; (b) a fiber optic element for conveying the optical energy, wherein the fiber optic element has an input end optically coupled to the focal surface to receive the optical energy and an output end to transmit the conveyed optical energy; and (c) a spectral filter optically coupled to at least one of the input and output ends of the fiber optic element, wherein the spectral filter has a filter passband configured to provide the fiber optic element with a pre-determined wavelength transmittance capacity, such that only pre-determined wavelengths of the optical energy are transmitted through the output end, thus achieving a customized spectral response.

Abstract: A hypothetical profile is used to model the profile of a structure formed on a semiconductor wafer to use in determining the profile of the structure using optical metrology. To select a hypothetical profile, sample diffraction signals are obtained from measured diffraction signals of structures formed on the wafer, where the sample diffraction signals are a representative sampling of the measured diffraction signals. A hypothetical profile is defined and evaluated using a sample diffraction signal from the obtained sample diffraction signals.

Abstract: The present invention describes a method and apparatus for the detection and measurement of surface imperfections within a predetermined size range, contained on the surface of a machined cast metal component. The invention provides a novel illumination and image acquisition technique that allows the inspection of large cast machined surfaces without movement of the component, sensor or illumination system during acquisition of an image. The invention allows for the inspection of large surfaces on objects up to 1,000 mm×650 mm in size. The inspection field of view can be divided in multiple regions, defined by computer aided design (CAD) model data. Each of these regions may apply a unique set of inspection criteria used for disposition of the component. Inspection regions generated using CAD drawings indicate exact position of features with respect to the manufacturing datum located on the surface and viewable as part of the acquired image.

Abstract: An automated optical inspection system, comprising at least one camera having a field of view; and at least one image scanning module comprising a plurality of objective modules arranged to have fields of view covering a portion of an article during inspection, and an image selection mirror mechanism, such as a pentaprism movable to sequentially select and transfer images of the fields of view from the objective modules to the at least one camera, and a beam splitter operative to simultaneously direct illumination from at least one illumination source to a portion of the article and to direct an image of the portion of the article to at least one camera, wherein the beam splitter is operative to pivot about at least one axis, thereby to create motion of the image of the article within the field of view of the camera. The objective modules may be arranged in a pair of back-to-back arcs each served by and partially encircling its own optical head.

Abstract: An exposure apparatus performs AGA measurement by using a predetermined sample shot group formed on a wafer, and decides an alignment parameter. The exposure apparatus executes wafer alignment processing and exposure processing by using the alignment parameter. The exposure apparatus notifies a central processing unit of AGA measurement results and the alignment parameter. An overlay inspection apparatus measures an actual exposure position on the exposed wafer, and notifies the central processing unit of the measurement result. The central processing unit optimizes alignment processing on the basis of the AGA measurement results, alignment parameter, and actually measured exposure position.

Abstract: Methods for grading gemstones, apparatus for grading gemstones, and systems that utilize such methods and apparatus are disclosed.

Abstract: The invention relates to methods of assessing one or more geometric properties of a particle of a substance using a Raman spectroscopic property of the substance. The method is useful, for example, for assessing particle sizes and size distributions in mixtures containing both particles of the substance and other materials.

Abstract: A method of measuring a mailpiece includes deflecting a laser beam through an arc, determining an angle at which the laser beam is currently directed, and calculating a dimension of the mailpiece based at least in part on the determined angle.

Abstract: A patterned dielectric layer is evaluated by measuring reflectance of a region which has openings. A heating beam may be chosen for having reflectance from an underlying conductive layer that is several times greater than absorptance, to provide a heightened sensitivity to presence of residue and/or changes in dimension of the openings. Reflectance may be measured by illuminating the region with a heating beam modulated at a preset frequency, and measuring power of a probe beam that reflects from the region at the preset frequency. Openings of many embodiments have sub-wavelength dimensions (i.e. smaller than the wavelength of the heating beam). The underlying conductive layer may be patterned into links of length smaller than the diameter of heating beam, so that the links float to a temperature higher than a corresponding temperature attained by a continuous trace that transfers heat away from the illuminated region by conduction.