Abstract:
L'invention concerne un procédé didentification d'images dune scène (1) qui comprend une étape dillumination de la scène par un faisceau de N longueurs donde, polarisé selon une direction déterminée, N étant un entier supérieur ou égal à 3. Il comprend les étapes suivantes : - acquisition simultanée pour chaque longueur donde dune image polarisée selon ladite direction, soit N images (11) notées X // (λi) avec i variant de 1 à N et dune image polarisée selon une direction perpendiculaire à ladite direction, soit N images (12) notées X ⊥ (λi), ces images X ⊥ (λ) étant spatialement distinctes des images X // (λi), - calcul pour chaque longueur donde dune image dintensité qui est une combinaison linéaire de X // (λi) et de X ⊥ (λi), à ces N images d'intensité correspondant donc pour chaque pixel un spectre dintensité, - calcul pour chaque longueur donde d'une image de contraste de polarisation à partir dun rapport dintensité calculé en fonction de X // (λi) et de X ⊥ (λi), à ces N images de contraste de polarisation correspondant donc pour chaque pixel un spectre de contraste de polarisation,- calcul dune image de la scène dite image de contraste spectro-polarimétrique et notée image CSP, chaque pixel de cette image étant obtenue à partir du spectre dintensité et du spectre de contraste du pixel considéré.
Abstract:
Optically diverse coded aperture imaging (CAI) comprises imaging a scene which is multi-spectrally diverse or polarimetrically diverse. A CAI system (10) allows light rays (12) from a scene to pass to a detector array (14) through a coded aperture mask (16) within an optical stop (18). The mask 16 has multiple apertures 16a, and produces overlapping coded images of the scene on the detector array (14). Detector array pixels receive and sum intensity contributions from each coded image. The detector array (14) provides output data for processing to reconstruct an image. The mask (16) provides for multi- spectral information to become encoded in the data. A linear integral equation incorporating explicit wavelength dependence relates the imaged scene to the data. This equation is solved by Landweber iteration to derive a multi-spectral image. An image with multiple polarisation states (polarimetric diversity) may be derived similarly with a linear integral equation incorporating explicit polarisation dependence.
Abstract:
Methods and apparatus for concentration determination using polarized light. The apparatus includes a first polarized light source having a first light source polarization axis and a second polarized light source having a second light source polarization axis generally perpendicular to the first light source polarization axis. Also, a first polarized light receiver having a first polarized light receiver polarization axis and configured to measure an intensity of light transmitted from the first light receiver polarizer and a second polarized light receiver having a second polarized light receiver polarization axis substantially perpendicular to the first light receiver polarization axis and configured to measure an intensity of light transmitted from the second light receiver polarizer, wherein the first and second light receiver polarization axes are generally +/- 45 degrees relative to the first and second light source polarization axes.
Abstract:
Four separately polarized beams are simultaneously measured upon diffraction from a substrate (W) to determine properties of the substrate. Linearly, circularly or elliptically polarized radiation is transmitted through a first beam splitter (N-PBS) and split into two polarized beams. These two beams are further split into two further beams using two further beam splitters, the further beam splitters (32,34) being rotated by 45° with respect to each other. The plurality of polarizing beam splitters enables the measurement of the intensity of all four beams and thus the measurement of the phase modulation and amplitude of the combined beams to give the features of the substrate. Algorithms are used to compare the four intensities of each of the polarized angles to give rise to the phase difference between the polarization directions and the ratio between the two main polarization direction amplitudes of the original polarized beam.
Abstract:
The present invention relates to a multi-energy system that generates and/or forms images of targets/structures by applying Mueller matrix imaging principles and/or Stokes polarimetric parameter imaging principles to data obtained by the multi-energy system. In one embodiment, the present invention utilizes at least one energy or light source to generate two or more Mueller matrix and/or Stokes polarization parameters images of a target/structure, and evaluates the Mueller matrix/Stokes polarization parameters multi-spectral difference(s) between the two or more images of the target/structure. As a result, high contrast, high specificity images can be obtained. Additional information can be obtained by and/or from the present invention through the application of image, Mueller matrix decomposition, and/or image reconstruction techniques that operate directly on the Mueller matrix and/or Stokes polarization parameters.
Abstract:
This application discloses a new method to record an image. It relates to microscopy and surface analysis in many scientific and technical fields. In particular it relates to the imaging and inspection of surfaces used in microelectronics: non-patterned and patterned wafers and photomasks. In the sense that it records electric amplitude, it relates to holography. Applications include microscopy, defect inspection, scatterometry, and optical metrology.
Abstract:
Die vorliegende Erfindung betrifft Verfahren zur Herstellung polarisationsempfindlicher bzw. polarisierender Filter sowie die Anwendung auf polarisationsempfindliche Photosensoren zur Messung der Polarisation des einfallenden Lichts, Ausgestaltungen von polarisationsempfindlichen Sensoren zur Messung von Drehwinkeln und starken elektrischen oder magnetischen Feldern sowie weiterhin polarisationserzeugende Wiedergabegeräte und Ausgestaltungen von polarisationserzeugenden Wiedergabegeräten zur Reproduktion polarisierter Signale oder zur Wiedergabe unabhängiger Signale.
Abstract:
The present invention relates to a system and method of detecting polarized identification indicia in real-time. A frame of image data is provided (110) having a plurality of pixels, wherein each pixel includes polarized light intensity information. An intensity value is determined for each of the pixels from the polarized light intensity information (120). A first portion of the pixels having intensity values within an intensity range is selected (130, 140). The pixels in the first portion having similar angle of linear polarization values within a tolerance range are analyzed (180), thereby detecting the polarized identification indicia in the image data (190).
Abstract:
A multi-energy polarization imaging method consisting of a multi-fusion, dual-rotating retarder / multiple-energy complete Mueller matrix-based polarimeter and dual-energy capabilities, has been invented. The term multifusion describes the use of several imaging functions altogether such as polarimetric imaging, dual-energy subtraction, multifocal imaging and other. By substracting polarimetric parameters such as degree of polarization, degree of linear polarization, degree of circular polarization, respectively, obtained with interrogation light beams of wavelengths λ 1 and λ 2 , he system, enhanced imaging is obtained. The system includes a light source for illuminating a target with a first quantity of light having a first wavelength and a second quantity of light having a second wavelength, the first and second wavelengths being different. A polarization-state generator generates a polarization state for each of the first and second quantities of light, and includes a first polarizer through which the first and second quantities of light are transmitted before entering a first waveplate. A polarization-state receiver evaluates a resulting polarization state of the first and second quantities of light following illumination of the target, the polarization-state receiver including a second waveplate through which the first and second quantittes of light are transmitted before entering a second polarizer. An optical image-capture device captures a first image of the target illuminated by the first quantity of light and a second image of the target illuminated by the second quantity of light. A processing unit assigns a weighting factor to at least one of the first and second images and evaluates a weighted difference between the first and second images to generate a multi-energy image of the target.