Abstract: In a method of determining the focus of a lithographic apparatus used in a lithographic process on a substrate, the lithographic process is used to form a structure on the substrate, the structure having at least one feature which has an asymmetry in the printed profile which varies as a function of the focus of the lithographic apparatus on the substrate. A first image of the periodic structure is formed and detected while illuminating the structure with a first beam of radiation. The first image is formed using a first part of non-zero order diffracted radiation. A second image of the periodic structure is formed and detected while illuminating the structure with a second beam of radiation. The second image is formed using a second part of the non-zero order diffracted radiation which is symmetrically opposite to the first part in a diffraction spectrum.

Abstract: A fragmented lens system for creating an invisible light pattern useful to computer vision systems is disclosed. Random or semi-random dot patterns generated by the present system allow a computer to uniquely identify each patch of a pattern projected by a corresponding illuminator or light source. The computer may determine the position and distance of an object by identifying the illumination pattern on the object.

Abstract: Provided is an alignment mark having a plurality of sub-resolution elements. The sub-resolution elements each have a dimension that is less than a minimum resolution that can be detected by an alignment signal used in an alignment process. Also provided is a semiconductor wafer having first, second, and third patterns formed thereon. The first and second patterns extend in a first direction, and the third pattern extend in a second direction perpendicular to the first direction. The second pattern is separated from the first pattern by a first distance measured in the second direction. The third pattern is separated from the first pattern by a second distance measured in the first direction. The third pattern is separated from the second pattern by a third distance measured in the first direction. The first distance is approximately equal to the third distance. The second distance is less than twice the first distance.

Abstract: A long-distance fiber optic monitoring system having a sensing unit and an analyzer that is remotely located from the sensing unit is provided. The sensing unit comprises a source of optical energy for injecting optical energy into the fiber optical cable and an optical detector configured to detect an optical return signal from the optical fiber. The detected optical return signal is associated with an acoustic signal impinging on the optical fiber. The analyzer receives a signal from the remote sensing unit via the optical fiber that is representative of the optical return signal, and determines a location of a disturbance based at least on the received signal. The representative signal can be transmitted from the remote sensing unit to the analyzer as an optical signal or via a metallic wired included with the optical fiber.

Abstract: Light from a light source device (4) is polarized through a polarizer (5) and is caused to impinge obliquely on an object (W) to be inspected. The resulting scattered light (SB) is received by a CCD imaging device (7) having an element (9) for separating scattered light disposed in a dark field. Component light intensities are worked out for an obtained P-polarized component image and an obtained S-polarized component image and a polarization direction is determined as a ratio of them. The component light intensities and the polarization directions are determined from images obtained by imaging of the light scattering entities in a state where stress is applied to the object to be inspected and in a state where stress is not applied thereto. The component light intensities and the polarization directions are compared with predetermined threshold values.

Abstract: A method of obtaining high dynamic range, spectrally, spatially and angularly resolved radiance of a sample surface of a sample by an electromagnetic irradiator irradiating electromagnetic radiation of controlled spectral distribution onto the sample surface and, using an electromagnetic sensitive sensor to register the reflected spectral distribution. The spectral distribution of the intensity of the electromagnetic field is modeled to have been reflected by a plurality of spatially well defined part-surfaces of the sample surface.

Abstract: For testing whether an optical fiber is properly connected to a device, a beam of light is output to the optical fiber. An intensity is detected of light reflected by the device back through the optical fiber in response to the beam of light. In response to the detected intensity, a determination is made of whether the optical fiber is properly connected to the device.

Abstract: An optical-component fabricating method includes arranging a mask that has both an optical component pattern and an alignment mark pattern and a wafer that is developed through the mask at predetermined positions; exposing the optical component pattern and the alignment mark pattern onto the wafer; developing the alignment mark pattern that is exposed on the wafer; observing a position of the developed alignment mark pattern and moving the wafer in accordance with the position; repeating the exposing, the developing, and the moving a predetermined number of times; developing all the optical component patterns on the wafer; and etching the developed optical component patterns.

Abstract: A method of error compensation in a chromatic point sensor (CPS) reduces errors associated with varying workpiece spectral reflectivity. The errors are associated with a distance-independent profile component of the CPS measurement signals. Workpiece spectral reflectivity may be characterized using known spectral reflectivity for a workpiece material, or by measuring the workpiece spectral reflectivity using the CPS system. CPS spectral reflectivity measurement may comprise scanning the CPS optical pen to a plurality of distances relative to a workpiece surface and determining a distance-independent composite spectral profile from a plurality of resulting wavelength peaks.

Abstract: In the component position measurement method, the position B of the component 1 when the laser beam is blocked (the laser beam blocking position) is measured with respect to the chuck position A of the component 1. Since the component 1 generates a large vibration (inclination) during the chuck is used, the position of the leading end (front end) C of the component 1 is computed using the inclination angle ? with respect to the measurement value of the deviation amount H of the laser beam blocking position B of the component 1 based on a similarity relationship of a triangle.

Abstract: A method for discrimination between a first (308) and a second surface (304) type based on reflectivity has a light source (416) that illuminates on a media surface. A photosensor (420) receives and measures the reflection value from the surface. A first gain element adjusts a voltage from the photosensor and a second gain element adjusts a current measurement supplied to the light source. A subtractor (530) for subtracting the first adjusted voltage (534) and the adjusted measurement (538) are subtracted to provide an output value close to zero with respect to the second surface and near a maximum with respect to the first surface. The adjusted reflection value and a threshold reference value (428) are compared (124) and indicates whether the first surface or the second surface is present.

Abstract: This blood examination apparatus examines cancer cells mixed in an examination object which is flowing blood, and includes: a flow cell through which the examination object is made to flow; an imaging optical system which light output from the examination object in an examination region in the flow cell enters, the imaging optical system forming an image of the light on a first image plane; a first Fourier transformation optical system which optically two-dimensionally Fourier-transforms the image formed on the first image plane by the imaging optical system to form the Fourier-transformed image on a second image plane; a spatial light filter which selectively allows a portion in a certain range around an optical axis of the first Fourier transformation optical system of the image formed on the second image plane by the first Fourier transformation optical system to pass through; and a second Fourier transformation optical system which optically two-dimensionally Fourier-transforms the portion which has passe

Abstract: To the end of three-dimensionally localizing light emitting marker entities of unknown orientation and unknown position in a sample, the light emitted by each single marker entity is imaged in at least two different ways onto at least one detection plane which corresponds to a focal plane (13) in the sample resulting in at least two images of the marker entity. Virtual x- and y-positions of the marker entity in parallel to the focal plane (13) are separately determined from the emitted light intensity distribution over each image of the marker entity. Further, the z-position of the marker entity normal to the focal plane is determined from the emitted light intensity distributions over the images of the marker entity. The real x- and y-positions of the marker entity in parallel to the focal plane (13) are determined based on its virtual x- and y-positions and on its z-position.

Abstract: A defect inspection device comprises an inspection optical system including a light source, a half mirror for reflecting illumination light emitted from the light source, a catadioptric objective lens for collecting reflected light from the sample by illumination light reflected by the half mirror, an imaging lens for focusing the reflected light transmitted through the catadioptric objective lens, a relay lens having a blocking member provided at a position at which specularly reflected light from the sample is focused by the imaging lens, and a detector for detecting specularly reflected light not blocked by the blocking member; and a computation processing unit for detecting defects of the sample on the basis of the signals detected by the detector.

Abstract: A position detector detecting an object's position includes: first, second and third light sources emitting first, second and third position detection light beams to form first, second and third intensity distributions in a detection area, a highest intensity portion of the second intensity distribution being shifted from that of the first intensity distribution, a highest intensity portion of the third intensity distribution being shifted from a straight line connecting the highest intensity portions of the first and second intensity distributions; a light detector detecting the first, second and third position detection light beams reflected by the object; and a position detection section detecting a two-dimensional coordinate of the object in a detection plane set in the detection area by comparing the intensities of the first and second position detection light beams, and comparing the intensities of the second and third position detection light beams.

Abstract: Apparatus and methods are described for determining particulate concentrations in an exhaust gas. One embodiment provides a method of analyzing particles in a gas using an apparatus including a probe and an analyzer. The method includes obtaining a sample of particle laden gas through the probe; obtaining ambient air through the probe; diluting the sample with the ambient air; and providing the diluted sample to the analyzer. Another embodiment provides an apparatus for analyzing particles in a gas. The apparatus includes a probe adapted to accept a gas or ambient air; a volume to dilute the gas with the ambient air; an analyzer responsive to particles in the gas; and electronics to operate the apparatus. The electronics instructs a user to first provide a sample and then provide ambient air into the volume, and then analyzes substantially all of the sample and ambient air for particles.

Abstract: A method may include injecting a test signal having a first optical launch power into a device under test via an optical splitter. The optical splitter includes at least two upstream ports and a downstream port and the test signal is injected in a first upstream port of the optical splitter. The device under test is coupled to the downstream port. Return loss associated with the device under test is measured at a second upstream input of the optical splitter. The RL measurement in stored a database. The injecting, measuring, and storing are repeated for a number of different optical launch powers.

Abstract: A system for controlling a light beam in an optical setup includes a light source that directs a collimated light beam along a path, through a sample, and toward the active area of a stationary detector. A lens is selectively movable into the path of the light beam for spreading the beam in instances where the path of the beam is altered by the sample between the source and the stationary detector. The detector, therefore, is held stationary. Adjustment mechanisms are provided for increasing the intensity characteristic of the light that reaches the detector to account for a decrease in intensity that occurs when the lens is in the path of the light beam to spread the beam.

Abstract: A surface position detecting apparatus according to an aspect of the present invention has a light-sending optical system which makes first light and second light from first and second patterns incident at different incidence angles to a predetermined surface to project an intermediate image of the first pattern and an intermediate image of the second pattern onto the predetermined surface; a light-receiving optical system which guides the first light and the second light reflected by the predetermined surface, to a first observation surface and to a second observation surface, respectively, to form an observation image of the first pattern and an observation image of the second pattern on the first and second observation surfaces; and a detecting section which detects a piece of position information of the observation image of the first pattern and a piece of position information of the observation image of the second pattern and calculates a surface position of the predetermined surface, based on the pieces

Abstract: An optical measurement apparatus using an optical fiber to measure the characteristic of an object to be measured arranged along the circumference of a circle includes a first pulley, a second pulley which is turnable on its own axis at a second angular velocity while revolving about the first pulley at a first angular velocity, and the optical fiber which is held by the second pulley and projects detection light on the object to be measured and receives reflected light from the object to be measured. The first angular velocity and the second angular velocity are the same in magnitude and opposite in the direction. Occurrence of a twist in the optical fiber is suppressed, and therefore, the optical measurement apparatus is capable of measuring the characteristics of the object to be measured with high accuracy.