Abstract: A terahertz ellipsometer, the basic preferred embodiment being a sequential system having a backward wave oscillator (BWO); a first rotatable polarizer that includes a wire grid (WGP1); a rotating polarizer that includes a wire grid (RWGP); a stage (STG) for supporting a sample (S); a rotating retarder (RRET) comprising first (RP), second (RM1), third (RM2) and fourth (RM3) elements; a second rotatable polarizer that includes a wire grid (WGP2); and a Golay cell detector (DET).

Abstract: Photoelectric autocollimation methods and apparatuses based on beam drift compensation are provided. The methods and apparatuses can be used to achieve a high autocollimation angle measurement accuracy. The apparatuses includes an autocollimator, a measurement mirror (12a), a beam drift monitoring and separating unit, a beam steering device (8), and a data processing controller (7). The beam drift monitoring and separating unit generate a reference beam with the same drift as the measurement beam. The measurement beam carries both angular deflection information of the measurement mirror and the angular beam drift information, while the reference beam carries only the angular beam drift information. The data processing controller gives out a signal to the beam steering device in real-time according to the magnitude of drift of the reference beam, to compensate the drift of the measurement beam.

Abstract: A robotic optical sedimentation recorder is described for the recordation of carbon flux in the oceans wherein both POC and PIC particles are captured at the open end of a submersible sampling platform, the captured particles allowed to drift down onto a collection plate where they can be imaged over time. The particles are imaged using three separate light sources, activated in sequence, one source being a back light, a second source being a side light to provide dark field illumination, and a third source comprising a cross polarized light source to illuminate birefringent particles. The recorder in one embodiment is attached to a buoyancy unit which is capable upon command for bringing the sedimentation recorder to a programmed depth below the ocean surface during recordation mode, and on command returning the unit to the ocean surface for transmission of recorded data and receipt of new instructions.

Abstract: The present invention relates to a method of identifying in a fluid by measuring the amount of optical rotation the fluid causes in a beam of polarized light. The invention further provides for the use of an optional optically active marker in the fluids in order the impact the amount of rotation the fluid will cause. The invention provides a convenient and reliable means for identifying the fluid before, during and/or after the fluid's use.

Abstract: Systems and methods for measuring a profile of a glass sample (300) are disclosed. The method includes scanning a polarization-switched light beam (112PS) through the glass sample and a reference block (320) for different depths into the glass sample to define a transmitted polarization-switched light beam. The method also includes measuring an amount of power in the polarization-switched light beam to form a polarization-switched reference signal (SR), and detecting the transmitted polarization-switched light beam to form a polarization-switched detector signal (SD). The method further includes dividing the polarization-switched detector signal by the polarization-switched reference signal to define a normalized polarization-switched detector signal (SN). Processing the normalized polarization-switched detector signal determines the profile characteristic.

Abstract: A heterodyne optical spectrum analyzer (10) is configured for analyzing spectral information of an optical input signal (15). The analyzer (10) comprises a local oscillator source (20) configured for generating an optical local oscillator signal (38). An optical mixer (25) is configured for receiving the input signal (15) and the local oscillator signal (38), and for outputting a plurality of different combined optical signals (50), each combined optical signal (50) being derived from the input signal (15) and the local oscillator signal (38). An opto-electrical receiver (30) having a plurality of inputs (52) is configured for receiving the combined optical signals (50) and for providing an opto-electrical conversion thereof, and an output (54) for outputting electrical signals representing the received combined optical signals (50). A signal processor (35) is configured for deriving spectral information of the input signal (15) by analyzing the electrical signals.

Abstract: The present invention relates to ellipsometer and polarimeter systems, and more particularly is an ellipsometer or polarimeter or the like system which operates in a frequency range between 300 GHz or lower and extending to higher than at least 1 Tera-hertz (THz), and preferably through the Infra-red (IR) range up to, and higher than 100 THz, including: a source such as a backward wave oscillator; a Smith-Purcell cell; a free electron laser, or an FTIR source and a solid state device; and a detector such as a Golay cell; a bolometer or a solid state detector; and preferably including a polarization state generator comprising: an odd bounce image rotating system and a polarizer, or two polarizers; and optionally including least one compensator and/or modulator, in addition to an analyzer.

Abstract: A portable token and systems and methods for identification and authentication of the same are disclosed. The portable token may be utilized for a variety of purposes and uses a thin section of rock as a unique identifying element, which is extremely resistant to forgery or duplication. Identification and authorization of tokens is achieved by a system that uses optical examination of the microstructure and the refractive properties of crystalline minerals within the identifying element, by transmitted polarized light techniques. Comparison between stored reference data and acquired examination data is the basis for verifying authenticity. The naturally-occurring three-dimensional orientations of the optical axes of mineral crystals contribute to the identification information by their effects.

Abstract: An embodiment of the present invention provides a method for aligning a phase retardation plate with a display panel comprising the following steps: S1: determining the positions of a first reference line on the phase retardation plate and a second reference line on the display panel, wherein the first reference line is the central line between the first and second ends of the phase retardation area, and the second reference line is the central line between the third and fourth ends of the display area; S2: obtaining a positional deviation between the first reference line and the second reference line by calculation; S3: adjusting the relative position between the phase retardation plate and the display panel according to the positional deviation.

Abstract: An examination kit allows for discovery of the axis of direction and stress areas of polarized lenses. The kit comprises a lower light box with a transparent work surface, two polarized film sheets, a dial gauge with notches defining allowable variation of axis direction and an upper polarized lens for viewing the tested polarized lens in various states and positions.

Abstract: A detector for detecting a birefringent object near a skin surface of a human body part or an animal body part includes a source for emitting optical radiation having first and second wavelengths and an incident polarization state. An imaging unit is configured to image the birefringent object near the surface includes a detection unit for detecting optical radiation scattered and/or reflected by the birefringent object and/or the surface at the first and second wavelengths. A control unit is configured to process a signal from the detection unit for discrimination between the birefringent object and the surface. The detection unit is configured to detect scattered and/or reflected optical radiation coming from the birefringent object and/or the surface, having a first polarization state corresponding to the incident polarization state and a second polarization state being different from the first polarization state.

Abstract: A system and method for the in-line analysis of protein-containing compositions for protein denaturation. The system and method employ providing a protein-containing composition in a container that can be directly used in an analytical method for evaluating the denaturation of a protein. The container can be directly employed in an analytical technique such as UV spectroscopy, circular dichroism, etc.

Abstract: Systems and methods of for measuring birefringence and stress in a sample made of ion-exchanged glass or a ceramic are disclosed, wherein the method includes digitally capturing TE and TM angular spectra of intensity versus pixel number for the sample. The TE and TM angular spectra are processed to minimize differences between respective regions of the TE and TM angular spectra. The amount of shift in pixels that best overlaps the processed TE and TM spectra is determined. The birefringence B is calculated by multiplying the pixel shift by the index resolution. The stress is calculated by multiplying the birefringence by the stress-optic coefficient.

Abstract: A device and method for detecting a liquid crystal display panel (100) can perform loaded electrical signal detection on an FFS-type liquid crystal display panel (100), thereby increasing the yield of products.

Abstract: An apparatus and associated method for characterizing a near field transducer (NFT) is provided that has computer instructions stored in memory and executable to perform computational logic that, in response to a selected electromagnetic radiation excitation of resonant collective oscillations on a surface of the NFT, compares a magnitude of a depolarization field associated with the excited resonant collective oscillations to a predetermined threshold to characterize the NFT in terms of demonstrated radiant efficiency performance.

Abstract: Polarization based channeled images are optically demodulated to produce directly viewable images. A channeled image flux is converted to an unpolarized flux by a phosphor or other sensor, and the resulting converted flux is demodulated by modulating at a spatial frequency corresponding to a modulating frequency of the channeled image flux. After modulation, the converted flux is spatially filtered to remove or attenuate portions associated with the modulation frequency and harmonics thereof. The resulting baseband flux is then imaged by direct viewing, projection, or using an image sensor and a display.

Abstract: Optical detection of molecules using a biochip having at least one reagent immobilizing area designed to receive one or more reagents and at least one calibration structure with a predetermined height to provide a height reference for optical measurement is disclosed. When the calibration structure is illuminated by a probe beam of light, a first reflected beam of light is reflected off the calibration structure, and a second reflected beam of light is reflected off the reagent immobilizing area. The first reflected beam and the second reflected beam are compared to determine a height at the reagent immobilizing area.

Abstract: This invention relates to a near real time optical compensation verification system for verifying a fiber or fiber component through internal or external compensation to achieve equivalently free space propagation of a broadband light when coupled into fiber. Preferably, no component is added to the fiber or fiber component, and the compensation method is realized through real time fiber bending, twisting or other means at either or both ends of a fiber or fiber component. The output optical characteristics of the compensated fiber or fiber component are measured by a polarimeter through changing the input light properties. The required multi-variable compensation to achieve Unitary Matrix free space condition is computed in near real time, and as the feedback to formulate the required compensation. The disclosed invention not only enhances yield in the fiber and fiber component, but also accelerates the optimization of optical fiber sensors employed free space fiber coil.

Abstract: Described are methods and systems for vicarious polarimetric calibration and performance validation of a remote sensor. The system includes a plurality of reflective mirrors configured and arranged to reflect radiation from a source of radiation onto the remote sensor with accurately known polarimetric properties. Each of the reflective mirrors are located so that the target images do not overlap. The remote sensor is configured to receive the radiation reflected from the plurality of reflective mirrors and store the received radiation as image data (e.g., the image of each mirror appears as a point target). The system includes a processor configured to process the received data to provide direct calibration and performance validation for each polarimetric or spectral channel of the remote sensor. In addition, the calibration method removes all atmospheric effects except for transmittance and provides reference targets that have high polarimetric contrast, full spectrum performance and easy to deploy.

Abstract: There is provided an electromagnetic field measurement apparatus capable of achieving correct and timely circuit operation detection in an area where electronic devices are mounted at high density. An electromagnetic field measurement apparatus includes: a laser light source; a polarized wave controller that linearly polarizes laser light; an optical fiber probe that has an electrooptic material or a magnetooptic material at its leading end and in which the laser light reflected at the leading end is subjected to polarization modulation in accordance with an electric field intensity or a magnetic field intensity; and an analyzer that converts the laser light reflected by the optical fiber probe into intensity modulated light. The laser light source emits time-multiplexed laser light of a plurality of wavelengths different from one another.

Abstract: A medical fluid delivery system includes a medical fluid delivery machine including a light source configured to generate a light beam; a polarizer configured to receive the light beam and to allow a portion of the light beam within the medical fluid to be transmitted through the polarizer, a photodetector to provide a measurement of an intensity of the light beam transmitted through a medical fluid and the polarizer; a medical fluid cassette operating with the medical fluid machine to pump the medical fluid, the medical fluid cassette loaded onto the medical fluid delivery machine such that the light source resides on a first side of the cassette and the photodetector resides on a second side of the cassette; and a computer configured to use the measurement of the intensity to determine whether the medical fluid can be delivered to a patient.

Abstract: A method is disclosed for manufacturing a chip-scale optics module for an optical interrogator. The method includes aligning a polarization axis of a linear polarizer to an angle of 45 degrees from a fast axis of a quarter wave plate to enable circular polarization of a beam, when a beam is introduced to the linear polarizer, coupling the linear polarizer to the quarter wave plate after the aligning to form a circular polarizing filter sheet and then dicing the circular polarizing filter sheet to obtain a plurality of chip-scale circular polarizing filters. Each of the chip-scale circular polarizing filters is diced to have an edge that defines a polarization location index for the linear polarizer. A linear polarizer plate face of one of the chip-scale circular polarizing filters is then positioned so that the linear polarizer plate face is aligned with and parallel to an output face of a laser, whereby the polarization axis of the linear polarizer is not orthogonal to a polarization axis of the laser.

Abstract: An image processor (101) according to a preferred embodiment of the present invention includes a polarized light source (102) and a polarization camera (103). In shooting an object (104), the object is irradiated with polarized light (105) that rotates its polarization plane. The polarized light is reflected from the object's surface and the polarized reflected light (106) reaches the polarization camera (103), thereby recording an image there. The polarization camera (103) includes a polarization image sensor (201), an intensity and polarization information processing section (202), a polarization plane control section (204), and an image capturing control section (205). By capturing an image every time the polarization plane control section (204) changes the polarization state of the polarized light, an intensity image Y and a polarization phase image P are obtained in association with each polarization state.

Abstract: An apparatus to calibrate a polarizer in a polarized optical system at any angle of incidence. The apparatus decouples the polarization effect of the system from the polarization effect of the sample. The apparatus includes a substrate with a polarizer disposed on the surface. An indicator on the substrate indicates the polarization orientation of the polarizer, which is in a predetermined orientation with respect to the substrate.

Abstract: A non-invasive device for measuring concentration levels of optically active substances, such as glucose, by determination of polarization plane turn angle in the infrared spectrum. Instant embodiments, measuring optical polarization shift, include a narrow-band optical source having a first linear polarizer; substantially illuminated by the source, a sample stage capable of temporarily immobilizing a sample; proximate to the sample stage and within a predetermined angular range with respect to the source illumination of the sample, a narrow-band optical detector capable of detecting polarization angles from the illuminated sample; and in conjunction with the source and the detector, a linear polarization angle comparator for comparing a polarization of the source with a polarization maxima region measured by the detector.

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: A reflector apparatus includes reflectors, which respectively radiate reflected waves in predetermined polarization directions. A polarized wave information reading circuit fixed to a moving body radiates a radio wave toward the reflecting apparatus from a transmitting antenna, receives reflected waves from the reflecting apparatus, and generates a received level difference signal that corresponds to a polarization direction of the received reflected waves. A position calculating circuit calculates a position of the polarized wave information reading circuit based on the received level difference signal.

Abstract: The present invention relates to ellipsometer and polarimeter systems, and more particularly is an ellipsometer or polarimeter or the like system which operates in a frequency range between 300 GHz or lower and extending to higher than at least 1 Tera-hertz (THz), and preferably through the Infra-red (IR) range up to, and higher than 100 THz, including: a source such as a backward wave oscillator; a Smith-Purcell cell; a free electron laser, or an FTIR source and a solid state device; and a detector such as a Golay cell; a bolometer or a solid state detector; and preferably including a polarization state generator comprising: an odd bounce image rotating system and a polarizer, or two polarizers; and optionally including least one compensator and/or modulator, in addition to an analyzer.

Abstract: A method for determining a clarity of a window of a vehicle has a step of evaluating an information item of at least one light beam furnished with a predetermined polarization in order to determine the clarity of the window.

Abstract: A system and method of use thereof that enables determining and setting sample alignment based on the location of, and geometric attributes of a monitored image formed by reflection of an electromagnetic beam from a sample and into an image monitor, which beam is directed to be incident onto the sample along a locus which is substantially normal to the surface of the sample.

Abstract: The present invention provides for the detection and display of polarization scrambling tissue without resolving the polarization state of the backscattered imaging beam. In one embodiment, we illuminate the tissue using two different polarizations. A first polarization determines a first image of high intensity while the second polarization determines a second image of low intensity. Comparison and combination of the first and second images determines tissue which scrambles the polarization in neighboring detection cells.

Abstract: Provided is a particle characterization device that can ensure measurement accuracy even though light detecting means has a single configuration, and enables the number of optical elements to be decreased as much as possible to suppress cost increase and reduce the number of adjustment places, and the particle characterization device has an incident side polarizer and an incident side ¼ wavelength plate as an illumination optical system mechanism and, as a light receiving optical system mechanism, an exit side ¼ wavelength plate and an exit side polarizer that can be rotated to a plurality of angle positions around a cell, wherein light attenuating means that prevents a polarization state from being changed is provided on a light path, and a light attenuation rate by the light attenuating means is controlled such that a detected light intensity at each measurement position falls within a measurement range of light detecting means.

Abstract: There is provided an automatic inspection apparatus and method for detecting stains on a polarizing plate using color difference analysis. The automatic inspection apparatus includes an inspection unit including at least one reference polarizing plate and a target polarizing plate or polarizing element mounted on the at least one reference polarizing plate; a light source unit disposed on one surface of the inspection unit and irradiating the inspection unit with light; an imaging unit disposed on the other surface of the inspection unit, imaging the target polarizing plate or polarizing element, and transferring an image thereof; and an arithmetic operation unit performing color difference analysis for individual inspection regions of the image of the target polarizing plate or polarizing element transferred by the imaging unit and detecting a blurred stain.

Abstract: A Fiber-optic current sensor for sensing electric current carried in an electric conductor (18). Its optical section comprises: a light source (1); a directional coupler (2) with two ports (2A, 2B) of two arms each; a radiation polarizer (3); a polarization modulator (4); a fiber line (17) coupled to a current-sensing fiber loop (11); a mirror (10); and a photodetector (22). The first port of the coupler (2) is coupled to the light source (1) and to the photodetector (22). Its second port is coupled via the radiation polarizer (3) to the polarization modulator (4). The polarization modulator comprises a magneto-sensitive element (5), around which a solenoid (6) is wound. The fiber loop (11) comprises a magneto-sensitive optical fiber with embedded linear birefringence. An electronic section comprises a signal generator (21) which drives the solenoid (6); and a signal processing unit which receives the optical signal from the photodetector (22).

Abstract: The present invention relates to a sensor using a tilted fiber grating to detect physical manifestations occurring in a medium. Such physical manifestations induce measurable changes in the optical property of the tilted fiber grating. The sensor comprises a sensing surface which is to be exposed to the medium, an optical pathway and a tilted grating in the optical pathway. The grating is responsive to electromagnetic radiation propagating in the optical pathway to generate a response conveying information on the physical manifestation.

Abstract: An orientation tracking system for a moving platform includes a transmitter which generates an beam having a known polarization with respect to a predefined coordinate system. The moving platform includes an ellipsometric detector capable of detecting the polarized beam when within the line-of-sight of the transmitter, and measuring its polarization state. The polarization state indicates the rotational orientation of the moving platform with respect to the predefined coordinate system. The beam could also be used to convey guidance commands to the platform.

Abstract: A method of processing IC units comprising the steps of: dicing said IC units from a substrate; delivering said IC units to a idle block; inspecting a face of said units as exposed during the dicing step using an inspection device whilst said units are on said idle block, then; engaging said units with a picker assembly; passing said units over a second inspection device to inspect an opposed face of said units.

Abstract: The invention relates to an optoelectronic sensor element (20) having at least one reception element (22, 22a, 22b, 22c, 22d) in front of which a polarizing structure (24, 24a, 24b, 24c, 24d) is arranged which is manufactured from an electrically conductive material, with the polarizing structure (24, 24a, 24b, 24c, 24d) having a contact connection (26) for the application of a defined tension and with the polarizing structure (24, 24a, 24b, 24c, 24d) being configured as a screen of the sensor element (20).

Abstract: The present invention provides an optical detection system in which a first mirror of the control unit is used to receive light beam and redirect it into a first one-dimensional off-axis parabolic mirror. The first one-dimensional off-axis parabolic mirror then directs the light beam to a cylindrical lens. Through the mechanism of reflection, the cylindrical lens further directs the light beam to a second one-dimensional off-axis parabolic mirror. The second one-dimensional off-axis parabolic mirror then directs the light beam into a second mirror. The detection unit of the system is used to detect the light beam coming from the control unit, so as to convert the light signals into electric signals for the analysis in the process unit afterwards.

Abstract: A method of authenticating a polymer film comprises measuring the thickness of a layer therein by white light interferometry and/or measuring the birefringence of a layer therein. The method, and devices to carry out the method, may be used in security applications, for example to test for counterfeit bank notes.

Abstract: A detector (550) for detecting light (248B) from a light source (248A) comprises a single array of pixels (574) and a first mask (576). The single array of pixels (574) includes a plurality of rows of pixels (574R), and a plurality of columns of pixels (574C) having at least a first active column of pixels (574AC) and a spaced apart second active column of pixels (574AC). The first mask (576) covers one of the plurality of columns of pixels (574C) to provide a first masked column of pixels (574MC) that is positioned between the first active column of pixels (574AC) and the second active column of pixels (574AC). Additionally, a charge is generated from the light (248B) impinging on the first active column of pixels (574AC), is transferred to the first masked column of pixels (574MC), and subsequently is transferred to the second active column of pixels (574AC).

Abstract: The present invention relates to a system and method for measuring a wavelength-resolved state of polarization, for calculating differential group delay of an optical signal under analysis (1) by means of taking multiple measurements of the spectrum of the signal under analysis (1) with spectral filtering means (3) with an optical output the power of which depends on the polarization of the input. The polarization at the input of the spectral filtering means (3) is modified by means of a polarization transformer (2) which sequentially selects a plurality of output states of polarization. The spectral filtering means (3) can comprise a filter based on stimulated Brillouin scattering amplification (10) simultaneously combining wavelength discrimination and polarization discrimination.

Abstract: An optical system is presented for use in measuring in patterned structures having vias. The system is configured and operable to enable measurement of a via profile parameters. The system comprises an illumination channel for propagating illuminated light onto the structure being measured, a detection channel for collecting light returned from the illuminated structure to a detection unit, and a modulating assembly configured and operable for implementing a dark-field detection mode by carrying out at least one of the following: affecting at least one parameter of light propagating along at least one of the illumination and detection channels, and affecting propagation of light along at least the detection channel.

Abstract: A system and method for detection of a target object/material includes identifying a polarimetric signal for a plurality of aspect angles. One/two-dimensional Mueller matrix image or one/two-dimensional Stokes vector image can be processed using power spectral analysis, wavelet and fractal analysis for further image, having increased discrimination with reduced false-ratio. In addition, each of the angular polarization states due to their association with a particular aspect angle are then cross-correlated to generate a two-dimensional image that relates the level of correlation with the aspect angle. Finally, the output information, including statistical parameters are fed to the input of a neural-fuzzy network for further optimization and image enhancement.

Abstract: Measuring the twist of a rotating shaft by means of a laser beam and polarizing filters. The measurement device includes a laser beam generator, two polarizing filters secured to the shaft and spaced apart from each other, and a laser radiation receiver receiving the laser beam after it has passed through both filters.

Abstract: Systems and methods for inspecting a specimen are provided. One system includes an illumination subsystem configured to direct light to the specimen at an oblique angle of incidence. The light is polarized in a plane that is substantially parallel to the plane of incidence. The system also includes a detection subsystem configured to detect light scattered from the specimen. The detected light is polarized in a plane that is substantially parallel to the plane of scattering. In addition, the system includes a processor configured to detect defects on the specimen using signals generated by the detection subsystem. In one embodiment, such a system may be configured to detect defects having a size that is less than half of a wavelength of the light directed to the specimen.

Abstract: Improving the throughput of systems for measuring birefringence of optical samples includes techniques for directing multiple beams through the photoelastic modulator component of the system so that, along with expanded detection mechanisms to accommodate the multiple beams, the heretofore scanning (via a single beam) of a line across the sample is considerably enlarged so that several lines covering a “swath” of the sample area is scanned by the system of the present invention.

Abstract: A solution sample holding method between two light-transmitting plate-like members for measuring light passing through a minute amount of solution sample, comprises a dripping step and a covering step. The dripping step is to drip a minute amount of solution sample in a drip area of a sample mounting face of a first light-transmitting member. The sample mounting face also includes a liquid-repellent area surrounding the drip area. The covering step is to cover the solution sample with a second light-transmitting member and to maintain a predetermined distance between the first light-transmitting member and the second light-transmitting member. The liquid-repellent area of the sample mounting face is covered with a liquid-repellent substance. The minute amount of solution sample is held in contact with the two light-transmitting members.

Abstract: A detector apparatus and method for detecting radiation emitted from a target comprising: a first transmissive polarizer (302) for polarizing radiation incident on the target; a second transmissive polarizer (304) for polarizing the radiation emitted from the target (303) and absorbing any remaining light polarized by the first polarizer; and at least one reflective polarizer (306) arranged between the first and second transmissive polarizers.

Abstract: A method and system to measure misalignment error between two overlying or interlaced periodic structures are proposed. The overlying or interlaced periodic structures are illuminated by incident radiation, and the diffracted radiation of the incident radiation by the overlying or interlaced periodic structures are detected to provide an output signal. The misalignment between the overlying or interlaced periodic structures may then be determined from the output signal.