2539results about "Light polarisation measurement" patented technology

An apparatus and method to determine a property of a substrate by measuring, in the pupil plane of a high numerical aperture lens, an angle-resolved spectrum as a result of radiation being reflected off the substrate. The property may be angle and wavelength dependent. The radiation that is reflected off the substrate is radially polarized.

An overlay measurement apparatus has a polarized light source for illuminating a sample with a polarized light beam and an optical system to capture light that is scattered by the sample. The optical system includes a polarizer for transmitting an orthogonal polarization component that is orthogonal to a polarization direction of the polarized light beam. A detector measures intensity of the orthogonal polarization component. A processing unitise connected to the detector, and is arranged to process the orthogonal polarization component for overlay metrology measurement using asymmetry data derived from the orthogonal polarization component.

An apparatus includes a first section operable to detect polarization-sensitive radiation emitted by an object, and a second section operable to determine a Jones matrix based on information obtained by the first section from the polarization-sensitive radiation. The second section thereafter transforms the Jones matrix into a Mueller matrix, the Mueller matrix being representative of properties of the object.

A method for detecting and localizing a target tissue within the body in the presence of ambient light in which an optical contrast agent is administered and allowed to become functionally localized within a contrast-labeled target tissue to be diagnosed. A light source is optically coupled to a tissue region potentially containing the contrast-labeled target tissue. A gated light detector is optically coupled to the tissue region and arranged to detect light substantially enriched in target signal as compared to ambient light, where the target signal is light that has passed into the contrast-labeled tissue region and been modified by the contrast agent. A computer receives signals from the detector, and passes these signals to memory for accumulation and storage, and to then to image processing engine for determination of the localization and distribution of the contrast agent. The computer also provides an output signal based upon the localization and distribution of the contrast agent, allowing trace amounts of the target tissue to be detected, located, or imaged. A system for carrying out the method is also described.

The present invention discloses simple and yet highly efficient configurations of optical coherence domain reflectometry systems. The combined use of a polarizing beam splitter with one or two polarization manipulator(s) that rotate the returned light wave polarization to an orthogonal direction, enables one to achieve high optical power delivery efficiency as well as fixed or predetermined output polarization state of the interfering light waves reaching a detector or detector array, which is especially beneficial for spectral domain optical coherence tomography. In addition, the system can be made insensitive to polarization fading resulting from the birefringence change in the sample and reference arms. Dispersion matching can also be easily achieved between the sample and the reference arm for high resolution longitudinal scanning.

Method and apparatus for reflected imaging analysis. Reflected imaging is used to perform non-invasive, in vivo analysis of a subject's vascular system. A raw reflected image (110) is normalized with respect to the background to form a corrected reflected image (120). An analysis image (130) is segmented from the corrected reflected image to include a scene of interest for analysis. The method and apparatus can be used to determine such characteristics as the hemoglobin concentration per unit volume of blood, the number of white blood cells per unit volume of blood, a mean cell volume, the number of platelets per unit volume of blood, and the hematocrit. Cross-polarizers can be used to improve visualization of the reflected image.

In embodiments of the present invention, systems and methods of a non-invasive imaging device may comprise an illumination source comprising an incident light source to direct light upon skin, and a detector for detecting the degree of polarization of light reflected from the skin. A system and method of determining a skin state may be based on an aspect of the polarization of the reflected light.

Methods of detecting one or more parameters of a medium are disclosed. The methods include providing a waveguide grating device, contacting the waveguide grating with a medium, propagating a signal having at least one signal attribute through the waveguide, and comparing the modified signal attribute to a known signal attribute to detect a parameter of the medium.

The present invention is a hand held dermoscopy epiluminescense device with a magnification lens and an associated ring of luminous diodes powered by an on board battery. Every other diode in the ring operates as first and second light sources. The even diodes are filtered by a first polarization ring and the odd diodes are filtered by a second polarization ring. Each polarization ring has an open center for the lens and openings sized and positioned to correspond to the even or odd diodes to only filter one set. A viewing polarizer is provided and is cross-polarized relative to the first polarization ring and is parallel-polarized with the second polarization ring. A three way switch which provides on demand cross-polarized, parallel-polarized and a combination thereof for epiluminescence. A second embodiment provides even diodes of a first color and odd diodes of a second color. A third embodiment employs the alternating colored diodes of the second embodiment as well as the cross and parallel polarization of the light from the diodes as found in the first embodiment.

The present invention discloses simple and yet highly efficient configurations of optical coherence domain reflectometry systems. The combined use of a polarizing beam splitter with one or two polarization manipulator(s) that rotate the returned light wave polarization to an orthogonal direction, enables one to achieve high optical power delivery efficiency as well as fixed or predetermined output polarization state of the interfering light waves reaching a detector or detector array, which is especially beneficial for spectral domain optical coherence tomography. In addition, the system can be made insensitive to polarization fading resulting from the birefringence change in the sample and reference arms. Dispersion matching can also be easily achieved between the sample and the reference arm for high resolution longitudinal scanning.

A system such as for sensing strain or temperature of an aircraft and for transmitting information in communication systems. A sensor array includes a first light responsive Bragg grating sensor having a first operating bandwidth and a second light responsive Bragg grating sensor having a second operating bandwidth. Each sensor modifies light provided to it at a wavelength indicative of changes in strain or temperature. The second sensor operates within a bandwidth which is different from the operating bandwidth of the first sensor. A tunable light source such as an LED and tunable etalon provides light for illuminating the first and second sensors, the provided light having a wavelength which varies within a band including the first and second bandwidths. A detecting circuit provides signals representative of light modified by the first and second sensors. A processor processes the representative signals to determine the strain and / or temperature.

A surface inspection system and method is provided which detects defects such as particles or pits on the surface of a workpiece, such as a silicon wafer, and also distinguishes between pit defects and particle defects. The surface inspection system comprises an inspection station for receiving a workpiece and a scanner positioned and arranged to scan a surface of the workpiece at the inspection station. The scanner includes a light source arranged to project a beam of P-polarized light and a scanner positioned to scan the P-polarized light beam across the surface of the workpiece. The system further provides for detecting differences in the angular distribution of the light scattered from the workpiece and for distinguishing particle defects from pit defects based upon these differences.

A method and device for optical measurements are presented for determining the concentration of a substance in patient's blood. Optical measurement sessions are applied to a measurement location in a blood containing medium during certain time period. The optical measurements include illumination of the measurement location with incident light of at least one selected wavelength, detection, at each measurement session, of at least two light responses of the medium characterized by at least two different polarization states of detected light, respectively, and generation of data representative thereof. Measured data so obtained is in the form of at least two time variations of the light responses of the medium characterized by different polarization states of detected light, respectively, a relation between the time variations being indicative of the concentration of the substance in blood.

The illumination profile of a radiation beam is initially measured using a CCD detector. A reference mirror is then placed in the focal plane of the high aperture lens and the reflected radiation measured. By comparing the illumination profile and the detected radiation it is possible to determine the transmission losses for S and P polarisation which can then be used in scatterometry modeling.

A microscope system for determining optical properties of a specimen includes a source of polarized light, a detector for detecting the intensity of light incident thereon, an optical path extending from the source to the detector, a condenser for providing light from the source to the specimen, an objective for receiving light from the specimen, a support for mounting the specimen, a sectored variable retarder mounted in the optical path, and a polarized light analyzer mounted in the path between the sectored variable retarder and the detector. The variable retarder has a multiple sectors. Each sector is individually addressable by a control signal that affects the light retardation characteristics of the sector.

An in vivo imaging device having an illumination system that creates a virtual source within a tissue region of a subject in a non-invasive manner. The illumination system transforms a maximum amount of illumination energy from a light source into a high contrast illumination pattern. The illumination pattern is projected onto the object plane in a manner that maximizes the depth to which clear images of sub-surface features can be obtained. The high intensity portion of the illumination pattern is directed onto the object plane outside the field of view of an image capturing device that detects the image. In this configuration, scattered light from within the tissue region interacts with the object being imaged. This illumination technique provides for a high contrast image of sub-surface phenomena such as vein structure, blood flow within veins, gland structure, etc.

A method of real-time processing and monitoring comprises the steps of blending a material of interest (e.g., an active pharmaceutical material), with a secondary material, (e.g., an excipient), illuminating the blended materials with light, reflecting light carrying information about the blended materials through at least one multivariate optical element (148) and detecting said light with a first detector (152), detecting a deflected portion of the information carrying light with a second detector (156), and determining in real-time at least one selected property of the blended materials based on the detector outputs.

A large number of properties of nanostructures depend on their size, shape and many other parameters. As the size of a nanostructure decreases, there is a rapid change in many properties. When the nanostructure is completely destroyed, those properties essentially disappear. Systems based on changes in properties of nanostructures due to the destruction of nanostructures are proposed. The systems can be used for monitoring the total exposure to organic, inorganic, organometallic and biological compounds and agents using analytical methods.

A flow cytometer includes an optical flow cell through which particles to be characterized on the basis of at least their respective side-scatter characteristics are caused to flow seriatim. A plane-polarized laser beam produced by a laser diode is used to irradiate the particles as they pass through a focused elliptical spot having its minor axis oriented parallel to the particle flow path. Initially, the plane of polarization of the laser beam extends perpendicular to the path of particles through the flow cell. A half-wave plate or the like is positioned in the laser beam path to rotate the plane of polarization of the laser beam so that it is aligned with the path of particles before it irradiated particles moving along such path.

A rotating compensator spectroscopic ellipsometer or polarimeter system having a source of a polychromatic beam of electromagnetic radiation, a polarizer, a stage for supporting a material system, an analyzer, a dispersive optics and a detector system which comprises a multiplicity of detector elements, the system being functionally present in an environmental control chamber and therefore suitable for application in wide spectral range, (for example, 130-1700 nm). Preferred compensator design involves a substantially achromatic multiple element compensator systems wherein multiple total internal reflections enter retardance into an entered beam of electromagnetic radiation, and the elements thereof are oriented to minimize changes in the net retardance vs. the input beam angle resulting from changes in the position and / or rotation of the system of elements.

An apparatus and method to determine the surface orientation of objects in a field of view is provided by utilizing an array of polarizers and a means for microscanning an image of the objects over the polarizer array. In the preferred embodiment, a sequence of three image frames is captured using a focal plane array of photodetectors. Between frames the image is displaced by a distance equal to a polarizer array element. By combining the signals recorded in the three image frames, the intensity, percent of linear polarization, and angle of the polarization plane can be determined for radiation from each point on the object. The intensity can be used to determine the temperature at a corresponding point on the object. The percent of linear polarization and angle of the polarization plane can be used to determine the surface orientation at a corresponding point on the object. Surface orientation data from different points on the object can be combined to determine the object's shape and pose. Images of the Stokes parameters can be captured and viewed at video frequency. In an alternative embodiment, multi-spectral images can be captured for objects with point source resolution. Potential applications are in robotic vision, machine vision, computer vision, remote sensing, and infrared missile seekers. Other applications are detection and recognition of objects, automatic object recognition, and surveillance. This method of sensing is potentially useful in autonomous navigation and obstacle avoidance systems in automobiles and automated manufacturing and quality control systems.

A rotating compensator spectroscopic ellipsometer or polarimeter system having a source of a polychromatic beam of electromagnetic radiation, a polarizer, a stage for supporting a material system, an analyzer, a dispersive optics and a detector system which comprises a multiplicity of detector elements, the system being functionally present in an environmental control chamber and therefore suitable for application in wide spectral range, (for example, 130-1700 nm). Preferred compensator design involves a substantially achromatic multiple element compensator systems wherein multiple total internal reflections enter retardance into an entered beam of electromagnetic radiation, and the elements thereof are oriented to minimize changes in the net retardance vs. the input beam angle resulting from changes in the position and / or rotation of the system of elements.

To provide a concentration measuring method which enables a stable and highly accurate concentration measurement while avoiding the step of making a background measurement.The concentration measuring apparatus includes: a concentration measuring contact that is brought into contact with a subject of measurement; a light source that emits light and enters the light into the concentration measuring contact; a polarizer that takes out p-polarized and s-polarized light components from the light which is passed through the concentration measuring contact into the subject of measurement, transmitted in the subject of measurement, and returned to the concentration measuring contact; a photodetector that determines at least the quantities of the p-polarized and s-polarized light components taken out by the polarizer; and calculating means that calculates the concentration of a specific component contained in the subject of measurement based on the determined results.

An image data set acquired by an optical coherence tomography (OCT) system is corrected for effects due to motion of the sample. A first set of A-scans is acquired within a time short enough to avoid any significant motion of the sample. A second more extensive set of A-scans is acquired over an overlapping region on the sample. Significant sample motion may occur during acquisition of the second set. A-scans from the first set are matched with A-scans from the second set, based on similarity between the longitudinal optical scattering profiles they contain. Such matched pairs of A-scans are likely to correspond to the same region in the sample. Comparison of the OCT scanner coordinates that produced each A-scan in a matching pair, in conjunction with any shift in the longitudinal scattering profiles between the pair of A-scans, reveals the displacement of the sample between acquisition of the first and second A-scans in the pair. Estimates of the sample displacement are used to correct the transverse and longitudinal coordinates of the A-scans in the second set, to form a motion-corrected OCT data set.

A process control method to monitor ion implantation process conditions by measuring the optical properties of a masking material is provided. A patterned masking material may protect underlying regions of a semiconductor substrate from undergoing a chemical or physical change during an ion implantation process. The patterned masking material, however, may also undergo a chemical or physical change during processing. The chemical or physical changes to the masking material during such processing may also cause the optical properties of the material to change. The optical properties of the masking material may be used to determine the concentration of ions implanted into the semiconductor substrate.

A fiber optic acoustic sensor system including an optical conductor having low reflectivity mirrors is provided. Optical sensors are provided by sections of the optical conductor bounded by pairs of the low reflectivity mirrors. Pulses of light are injected into the optical conductor and reflected by the low reflectivity mirrors. The reflected pulses of light are processed using a compensating interferometer to generate interference patterns representative of the environmental conditions acting upon the optical conductor.

An alignment target includes periodic patterns on two elements. The periodic patterns are aligned when the two elements are properly aligned. By measuring the two periodic patterns with an incident beam having a single polarization state and detecting the intensity of the resulting polarized light, it can be determined if the two elements are aligned. The same polarization state may be detected as is incident or different polarization states may be used. A reference measurement location may be used that includes a third periodic pattern on the first element and a fourth periodic pattern on the second element, which have a designed in offset, i.e., an offset when there is an offset of a known magnitude when the first and second element are properly aligned. The reference measurement location is similarly measured with a single polarization state.

Disclosed are system and method for characterizing a system consisting of a fluid sample on a two sided stage, utilizing data obtained by applying, from both sides thereof, beams of electromagnetic radiation to a fluid coated surface in a containing cell volume. The beams can have the same or different wavelength content and / or polarization state, and can be applied at the same or different magnitude angles-of-incidence, and a third typically unpolarized beam can be applied at a normal angle-of-incidence.

An apparatus and a method of depositing a dielectric material film, including steps of initiating a process of depositing a dielectric material film under at least one controllable initial condition in an apparatus comprising a dielectric material deposition chamber and a spectroscopic ellipsometer; and measuring, by the spectroscopic ellipsometer, at least one ellipsometric parameter of the dielectric material film during the process of depositing the film.

An optical medium having a cavity that defines a variable gap is provided. The optical medium is used in an optical sensor, laser, and variable frequency resonator, by way of example. The cavity is physically altered in response to changes in a measurable parameter like pressure, temperature, force, flow rate, and material composition. The optical medium is characterized in some embodiments by having a cavity disposed near or within a high Q optical resonator. The optical resonator can be formed by various structures of which Bragg reflector cavities, ring resonators, microdiscs, and microspheres are examples. The optical resonator is preferably coupled to a laser source. The altering of the cavity affects the resonance condition within the optical resonator and thereby the laser signal of the system. If the laser source is a mode locked laser, the repetition rate of the pulse train changes in response to changes in the measurable parameter. If the laser source is a CW source the frequency of the laser signal is dependent upon a measurable parameter.