Abstract: Reflectometer, ellipsometer, polarimeter or the like system, which functionally comprise means for providing gas confined in a mini-chamber near the surface of a sample, at a location at which a beam having UV, VUV, IR and NIR wavelengths of electromagnetic radiation is caused to be impinged thereupon.

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: An optical rotating power measurement method comprising: an optical rotating power data acquisition step of starting measurement of the optical rotating power of the sample in a measurement apparatus during a temperature changing process where a controller controls the temperature of the sample such that the temperature reaches the predetermined temperature and of obtaining temperature data and optical rotating power data of the sample as time passes during the temperature changing process; and a data processing step of obtaining a straight line relationship data between the temperature data and the optical rotating power data, by using the fact that the optical rotating power of the sample is proportional to a measurement temperature; wherein the optical rotating power data of the sample at the predetermined temperature or the temperature dependence data of the optical rotating power of the sample is determined based on the straight line relationship data.

Abstract: A structure formed on a semiconductor wafer is examined by obtaining measurements of cross polarization components of diffraction beams, which were obtained from scanning an incident beam over a range of azimuth angles to obtain an azimuthal scan. A zero azimuth position is determined based on the azimuthal scan. The cross polarization components are zero at the zero azimuth position. A measured diffraction signal is obtained using an azimuth angle to be used in optical metrology of the structure. Misalignment of the azimuth angle is detected using the measured diffraction signal and the determined zero azimuth position.

Abstract: This invention solves a problem of registration and improves signal-to-noise ratio (SNR) when using division-by-focal-plane array to produce multiple polarization images. This is achieved by processing a sequence of angular-position-dithered frames to generate a high-definition, Nyquist-sampled, integrated image for each of the polarizations. The integration method transforms individually under-sampled, high-resolution image frames into resultant high-resolution frames that meet the Nyquist sampling criterion. During the resampling transformation, each polarization or waveband is resampled to produce precise registration to the other polarizations, since registration offsets are fixed and defined by the arrangement of the polarized pixels in the focal-plane-array. In the most straight-forward implementation, these offsets would be integer pixel shifts in X and Y.

Abstract: The present invention relates to an assembly and method for measuring the optical activity of a stimulus of interest. The assembly comprises a source of incident electromagnetic radiation (1), a lens arrangement (2), an input polariser (3), a planar waveguide structure (4) (or an optical fiber), an output polariser (5), a lens arrangement (6) for focussing the output electromagnetic radiation and a detector. The polarisation of the incident electromagnetic radiation relative to the planar waveguide structure (4) is determined by the input polariser (3). The planar waveguide structure in this embodiment comprises a silicon substrate layer (4c) and an absorbent layer (4e). The silicon oxynitride layer (4c) acts as the reference waveguide and the absorbent layer (4e) acts as the sensing waveguide. The sensing waveguide (4e) is exposed in the localised environment (8) to a sample containing the stimulus of interest which is optically active.

Abstract: The present invention relates to a device and a method for measuring an axial polarizing angle of a polarizer. The apparatus can have a to-be-measured polarizer disposed therein, and comprises a light generating device, a light polarizing device and a measurement comparison device. The light generating device provides a light source. The light polarizing device is disposed corresponding to the light generating device to load the to-be-measured polarizer, and measures a light signal after the light source passes through the to-be-measured polarizer without rotating the to-be-measured polarizer, and transforms it into readable data. The measurement comparison device is electrically connected with the light polarizing device and has at least one preset comparison data to receive the data provided by the light polarizing device and compare it with the comparison data.

Abstract: To effectively reduce a measurement error in a parameter indicating two-dimensional spatial distribution of a state of polarization generated by variations in retardation of a birefringent prism pair due to a temperature change or other factors, while holding a variety of properties of an imaging polarimetry using the birefringent prism pair. By noting that reference phase functions ?1(x, y) and ?2(x, y) are obtained by solving an equation from each vibration component contained in an intensity distribution I(x, y), the reference phase functions ?1(x, y) and ?2(x, y) are calibrated concurrently with measurement of two-dimensional spatial distribution S0(x, y), S1(x, y), S2(x, y), and S3(x, y) of Stokes parameters.

Abstract: A method of nonlinear polarimetry for measuring higher order moments of the E field of an optical signal is provided. The method includes imposing a phase delay on a first polarization of a received optical signal with respect to a second polarization of the optical signal to produce an intermediate optical signal having a time varying polarization. A polarization of the intermediate optical signal is suppressed. The intermediate optical signal is detected with a plurality of photodetectors, with at least one photodetector configured to be responsive to a nonlinear optical process. Spectra of the photodetector outputs are calculated to determine higher order moments of the E field, and the moments are transformed to obtain the polarization measurement.

Abstract: A new generation polarimetry apparatus and methodology is disclosed, which involve passing polarized light through a sample including a chiral analyte, where the analyte is under the influence of a periodically varying magnetic field. The apparatus also utilizes optical heterodyne detection and lock-in detection at higher order harmonics of the magnetic field modulation frequency to improve sensitivity and detection limits of optical properties of chiral analytes.

Abstract: A scanning laser polarimetry (SLP) system that measures in vivo retinal nerve fiber layer (RNFL) retardance (?N, ?N) in a single measurement without a variable corneal compensator (VCC). The diagnostic signal is biased so that the detected RNFL retardance orientation angles are sufficiently similar at adjacent pixels in the retinal polarimetric image to permit resolution of the orientation angle ambiguity in a single polarimetric image without repeating the measurement at another signal polarization state. With a simple bias retarder, the effects of anterior segment retardance (?C, ?C) can be removed from a single polarimetric image of the retina without a VCC. Alternatively, from two single polarimetric images obtained at two different bias retarder positions, the anterior segment retardance magnitude ?C and orientation ?C and the RNFL retardance magnitude ?N and orientation ?N can all be determined from the peripapillary RNFL image region alone.

Abstract: Improved methodology for monitoring deposition or removal of material to or from a process and/or wittness substrate which demonstrates a negative e1 at some wavelength. The method involves detection of changes in P-polarized electromagnetism ellipsometric DELTA at SPR Resonance Angle-of-Incidence (AOI) to monitor deposition of and/or removal of minute amounts of materials onto, or from, said process and/or witness substrate. The methodology can optionally monitor ellipsometric PSI, and involves simultaneously or sequentially applying non-P-polarized electromagnetism at the same angle of incidence, or electromagnetic radiation of any polarization at a different angle-of-incidence and wavelength to the process or wittness substrate and application of conventional ellipsometric analysis.

Abstract: A spectrometer generates Vibrational Circular Dichroism (VCD) measurements having an exceedingly high signal-to-noise ratio, as well as a greater wavelength range over which measurements may be accurately provided. This is achieved by utilizing reflective optics (preferably solely reflective optics, i.e., no refractive elements) to supply a concentrated and collimated input light beam to a sample within a sample cell, and similarly collecting the light output from the sample cell via reflective optics for supply to a detector.

Abstract: This application teaches various implementations of methods and in-line polarimeters with free-space sampling elements to sample four sample beams for determining the polarization state of input light. In one exemplary implementation, a device in this application includes four optical polarization analyzers arranged in series to form an optical path in free space to split four sample beams with four different states of polarization from an input optical beam propagating along the optical path. Each optical polarization analyzer transmits a majority of the input optical beam along the optical path and splits a fraction of the input beam as a respective sample beam. The device also includes four optical detectors respectively positioned in optical paths of the four sample beams to convert the sample beams into four detector signals indicative of optical power levels of the four different states of polarization, respectively.

Abstract: Techniques and devices for monitoring polarization of light using at least two polarization elements where the difference between the outputs of the two polarization elements are used to monitor a change in polarization.

Abstract: A fiber polarimeter has one or more oblique fiber Bragg gratings disposed one behind the other in a fiber. The fiber Bragg gratings couple out portions of a light wave input to the fiber depending on its polarization. For more than one fiber Bragg grating a wave plate is disposed in the fiber between consecutive fiber Bragg gratings. The portions of the light wave from the fiber Bragg grating(s) are detected to produce measurement data that is used to calculate four Stokes parameters for determining polarization, degree of polarization and/or power of the light wave.

Abstract: Apparatus and method for sensing and measuring optically active material in a sample, comprising: a) a light source emitting light of a wavelength that can pass through the sample; b) a light transparent sample container for holding the sample; c) a linear polarizer interposed between the light source and the sample for producing a polarized light beam; d) a symmetrical linear split-field polarizer fixedly positioned to intercept the polarized light that passed through the sample; e) detectors to detect the split light beams passing through each polarizer of the split-field polarizer; f) means to amplify the current or voltage passing through each of the detectors; g) a differential amplifier; h) a data processor; i) a display; and j) electronic circuitry to operate the apparatus and provide an output on the display.

Abstract: In a polarizing plate grading method a first measurement range A1 is chosen on a polarizing plate. After conducting an initial measurement by putting the polarizing plate under X1° C. for Y1 hours, the first measurement range is measured to obtain the maximum chromatic value Z1max (NIT,cd/m), and the minimum chromatic value Z1min. The minimum value is subtracted from the maximum value to obtain the net chromatic difference value W1. The temperature change measurement is conducted by putting the polarizing plate under X2° C. for Y2 hours and, then, the recovery measurement is conducted on the polarizing plate by putting the polarizing plate under X3° C. for Y3 hours. A first measurement range is measured to obtain the maximum chromatic value Z3max and the minimum chromatic value Z3min. The minimum chromatic value is subtracted from the maximum chromatic value to obtain the net chromatic difference value W3.

Abstract: A polarization modulation photoreflectance technique has been developed for optical characterization of semiconductor electronic interfaces. By using a laser source in conjunction with polarization state modulation, a polarization modulation spectroscopy technique may be used to characterize the optical response of semiconductor materials and structures. Disclosed methods and instruments are suitable for characterization of optical signatures of electronic interfaces, including characterization of electric fields at semiconductor interfaces.

Abstract: A calibration system is integrally provided with a polarimeter in which the calibration system and the polarimeter each receives a radiance sample from a spectral band of a scene. Radiances provided by the calibration system used to provide the relative responsivity calibrations among the polarimeter channels are essentially depolarized so as to provide the measurement data required to update the relative responsivity factors for the polarimeter channels. The unpolarized radiances from the calibrator are interspersed with scene data collected directly by the polarimeter, so that the polarimeter can effectively be recalibrated for each set of scene data obtained by the polarimeter. Such tracking of the calibration data can be studied for trends to assess instrument stability and to assess the appropriate means to preserve the measurement accuracy over periods where such changes occur.

Abstract: A structure formed on a semiconductor wafer is examined by directing an incident beam at the structure at an incidence angle and a azimuth angle. The incident beam is scanned over a range of azimuth angles to obtain an azimuthal scan. The cross polarization components of diffracted beams are measured during the azimuthal scan.

Abstract: Method and apparatus for testing of LCD panels is disclosed. An LCD panel under test is mounted to a translatable table between a polarization state generator and polarization state analyzer. For each location on the screen to be tested, a continuum of known polarization states are launched through the LCD screen and detected by the polarization state analyzer. Electrical signals representative of such polarization states are acquired by a computer. Within the computer, a model of polarization properties of the LCD panel is developed based on estimations of what the physical parameters of the LCD panel are believed to be. RMS differences between simulated polarization properties and measured polarization properties are minimized by iteratively refining the modeled physical cell properties, at which point cell thickness and other physical parameters of the LCD screen may be deduced.

Abstract: A liquid crystal based polarimetric system, a process for the calibration of this polarimetric system, and a polarimetric measurement process intended for measuring the representative parameters of a sample in which the polarimetric system contains an excitation section emitting a light beam that passes through a polarization state generator (PSG) and onto a sample. After reflection or transmission by the sample, the beam goes through an analysis section with a polarization state detector (PSD). The PSG and PSD each have a first and a second liquid crystal elements LCj (j=1,2) having, for each LCj element of the PSG (respectively for each LCj element of the PSD), an extraordinary axis making an angle ?j (resp. ??j) with respect to the polarization direction (i), and a retardation ?j (resp (??j) between its ordinary and extraordinary axes, the liquid crystals LCj elements being positioned in reverse order in the PSD with respect to the LCj elements of the PSG.

Abstract: To measure the concentration of an optically active substance in a solution without contacting the solution, the concentration measuring apparatus of the present invention includes: a light source for outputting linearly polarized light; a light intensity detecting element disposed opposite the light source with a sample placed therebetween; an optically active liquid crystal element placed between the light source and the light intensity detection circuit; a control circuit which controls the voltage to be applied to the optically active liquid crystal element so that an output value from the light intensity detecting element will in effect take an extreme value; and a concentration computing circuit for computing the concentration of an optically active substance in the sample, based on an output from the control circuit.

Abstract: Light from a light source 10 is linearly polarized by a polarizer 11. Then it propagates via a half-mirror 12 almost parallel to the normal to a reflective liquid-crystal panel 13 and falls on the reflective liquid-crystal panel 13. The reflected light reflected by the reflective liquid-crystal panel 13 is received by a detector 15 via the half-mirror 12 and an analyzer 14. In this state, the reflective liquid-crystal panel 13 is rotated about an axis almost parallel to the normal to the reflective liquid-crystal panel 13 and an angle (extinction angle) at which the output signal of detector 15 reaches minimum is measured. Then, the gap of the reflective liquid-crystal panel 13 is detected based on the measured extinction angle.

Abstract: An improved method and apparatus for the measurement of the polarization of light uses nonlinear polarimetry. The higher order moments of the E field are measured and then transformed into standard polarimetry parameters yielding the polarization of the light. In a first embodiment, the light to be measured is transmitted through a rotating retarder. The retarder is optically coupled to a fixed analyzer and light is then detected by linear and nonlinear photodetectors. The spectra from the detectors is calculated and transformed, to obtain the polarization. In a second embodiment, the light to be measured is received by an optical fiber comprising a plurality of fiber birefringences to retard the light. Polarization sensitive gratings along the length of the fiber scatter the light, and photodetectors detect the scattered light. Apparatus in two preferred embodiments can perform the inventive method.

Abstract: A calibration system is integrally provided with a polarimeter in which the calibration system and the polarimeter each receives a radiance sample. Radiances provided by the calibration system used to provide the relative responsivity calibrations among the polarimeter channels are essentially depolarized so as to provide the measurement data required to update the relative responsivity factors for the polarimeter channels. The unpolarized radiances from the calibrator are interspersed with scene data collected directly by the polarimeter, so that the polarimeter can effectively be recalibrated for each set of scene data obtained by the polarimeter. Another part of the calibration system may be used to adjust the scaling of the polarization calculated from the scene data obtained by the polarimeter. This is achieved by providing radiances which are essentially 100% polarized.

Abstract: An optical apparatus that measures a polarization dependent characteristic of a measured object includes a light source for emitting non-linearly polarized light in an extreme ultraviolet region or an X-ray region, and a rotary polarizer for reflecting the light emitted from the light source, the polarizer including a set of mirrors repeating three or more reflections and being arranged such that an optical axis of incident light and that of outgoing light are aligned with the same straight line.

Abstract: A monochromator system applicable in spectrophotometer, polarimeter and ellipsometer systems which operate over a large range of wavelengths, including a stage which enables position adjustment of the location of a source of electromagnetic radiation in lateral (X), longitudinal (Y) and vertical (Z) directions, from a common location outside an enclosure, and including multiple detector systems mounted in a manner which allows easily, sequentially, via mechanical motion, placing a first and then a second thereof so as to receive a beam of electromagnetic radiation.

Abstract: A method for optical stress analysis comprises the steps of directing an incident beam of polarized light to the sample to be analyzed and analyzing a light bundle exiting the sample in two detection channels extending perpendicular to one another with respect to the polarization direction, providing that the incident beam is elliptically polarized, carrying out the elliptical polarization with an elliptic shape having a comparatively large ratio of the large principal axis to the small principal axis, the direction of rotation of the elliptical polarization of the incident beam changing periodically and using two alternative states of the direction of rotation for each measurement process, adjusting the detection channels which extend perpendicular to one another corresponding to the position of the principal axes of the ellipse and carrying out the difference between two measurements consecutively with the same beam intensity of the incident beam and the same ratio of principal axes, but with opposite direc

Abstract: This invention concerns an ellipsometer for the examination of a sample whereby the ellipsometer has a broadband light source on the emitter side and a detector on the receiver side for a receiver light beam reflected from the sample. A refractive optic for the generation of a measuring spot on the sample and an aperture arranged on the emitter side for the definition of a measuring spot on the sample. The spectroscopic ellipsometer of the present invention makes it possible to easily produce a precisely defined measuring spot on the sample.

Abstract: In a process of manufacturing a semiconductor device, after a gate oxide film is formed, the thickness of the gate oxide film is measured by measuring an exposure period defined from a time at which the oxide film is formed to a time at which the thickness of the oxide film is measured. In addition, if necessary, the measurement of the oxide film is corrected to determine the real thickness based on the exposure period. Accordingly, the thickness of the gate oxide film can be measured accurately.

Abstract: In-line optical polarimeters and techniques for calibrating such polarimeters are described. In one implementation a polarimeter integrates components in free space to enhance device performance.

Abstract: This invention provides methodology for the measurement of both low and high levels of scattered radiation produced by decorative and barrier coatings and plastics. Measurements of low levels are especially important for coatings used in automotive applications. The method is based on the illumination of the sample with radiation and collection of only the portion of the radiation scattered from the coating before, during and after the testing step and relating the optical signal from the tested portion of the sample material to the untested portion of the material and/or a standard. Through the practice of the invention, a large number of coating samples, as in an array, may be analyzed for their optical quality, principally haze, either after coating and curing, and/or after subjection of such coatings samples to elongation stresses, and/or abrasion testing, solvent exposure, hydrolytic stability testing, and temperature exposure.

Abstract: Concentration of a solute in a solution is determined. Light from a light source is received at a chamber containing the solute and the solution. The light is transmitted along an optical path length of the chamber, through the solute and the solution, and output from the chamber. The light output from the chamber is detected by a detector. The optical path length of the chamber is selected to optimize sensitivity of the detector. The concentration of the solute in the solution is determined based on the light received by the detector.

Abstract: A fiber polarimeter has one or more oblique fiber Bragg gratings disposed one behind the other in a fiber. The fiber Bragg gratings couple out portions of a light wave input to the fiber depending on its polarization. For more than one fiber Bragg grating a wave plate is disposed in the fiber between consecutive fiber Bragg gratings. The portions of the light wave from the fiber Bragg grating(s) are detected to produce measurement data that is used to calculate four Stokes parameters for determining polarization, degree of polarization and/or power of the light wave.

Abstract: Methods and apparatus for optical Stokes polarimetry are provided. A polarimeter according to this invention includes a rotatable waveplate, including a variable birefringent material, and a polarizer optically downstream from the waveplate. The polarimeter can be integrated into a guided wave structure.

Abstract: In a polarimeter for analyzing a state of polarization of a light beam incident thereon, the polarimeter including first and second variable retarders configured to exhibit first and second retardance values, respectively, variable over an overall retardance range, and a detector arrangement, a method includes the steps of directing the light beam through the first and second variable retarders and sweeping a selected one of the first and second retardance values progressively and unidirectionally through at least a part of the overall retardance range to produce a plurality of retardance values. The method further includes the steps of, for the plurality of retardance values, detecting at the detector arrangement at least a spatial portion of the beam and extracting the state of polarization based on the spatial portion of the light beam detected at the detector arrangement corresponding to the plurality of retardance values.

Abstract: A non-intrusive method of characterizing particles through inverse analysis of experimental data based on measurements using elliptically polarized radiation is provided. A database of theoretical absorption and scattering data sets for particles is compiled. Optimum settings for an experimental test to gather an experimental absorption and scattering data set are determined and the experimental test is conducted. The experimental absorption and scattering data set is then compared to the theoretical absorption and scattering data sets of the database of theoretical absorption and scattering data sets in order to determine an absorption and scattering data set which differs the least from the experimental absorption and scattering data set in order to characterize the particles.

Abstract: State of polarization detectors and polarization control systems are disclosed. For example, the invention features an integrated optical assembly including: (i) a series of polarization-sensitive interfaces defining an optical beam path for an input optical beam to pass through the assembly, wherein each polarization-sensitive interface derives a sample beam from the input beam; and (ii) one or more retardation layers each positioned between a different pair of the polarization-sensitive interfaces, wherein the retardation layers are integrally coupled with the polarization-sensitive interfaces, and wherein the retardation layers and polarization-sensitive interfaces cause each sample beam to have an intensity that provides different information about the state of polarization of the input beam.

Abstract: A sample cell in a polarimeter comprises a thermally conductive body enclosing a substantially cylindrical internal volume with an insulating outer cover which leaves one face exposed for complementarily contacting a temperature controlled base plate so as to keep the sample cell at a predetermined temperature, and a means for positioning the sample cell at a predetermined position such that a measuring light beam longitudinally passes through the sample cell. The water jacket system required for the conventional cylindrical sample cells is eliminated. A cell holder for holding a cylindrical sample cell in a polarimeter comprises a heat transfer element having a concave cylindrical heat transfer surface for complementarily contacting an external cylindrical surface of the cylindrical sample cell so as to keep the sample cell at a predetermined temperature.

Abstract: A polarimeter system that averages multiple retardance measurement samples to cancel the effects of system birefringence in the diagnostic path. The retardance measurement errors arising from system birefringence have a symmetry that repeats over each complete cycle of optical signal rotation cycle. This symmetry is such that averaging the four retardance measurements collected over one complete rotation cycle cancels the effects of system birefringence, leaving a mean retardance measurement free of residual polarization bias. Apparatus is provided for determining the birefringence, thickness, and fiber orientation of the nerve fiber layer at the fundus of the eye by measuring the polarization bias induced in a return beam of polarized light that is reflected at the ocular fundus from an incident beam of a known polarization state. A corneal polarization compensator cancels the birefringent effects of the cornea and other portions of the eye anterior to the fundus.

Abstract: In a polarimeter for analyzing a state of polarization of a light beam incident thereon, the polarimeter including first and second variable retarders configured to exhibit first and second retardance values, respectively, variable over an overall retardance range, and a detector arrangement, a method includes the steps of directing the light beam through the first and second variable retarders and sweeping a selected one of the first and second retardance values progressively and unidirectionally through at least a part of the overall retardance range to produce a plurality of retardance values. The method further includes the steps of, for the plurality of retardance values, detecting at the detector arrangement at least a spatial portion of the light beam and extracting the state of polarization based on the spatial portion of the light beam detected at the detector arrangement corresponding to the plurality of retardance values.

Abstract: An optical assaying method and system having a movable sensor is described. In one aspect, the present invention is a sensing system having a rotating sensor disk coated with indicator dyes sensitized to a variety of substances. In this configuration the sensing system further includes a detector for sensing spectral changes in light received from one or more of the indicator dyes. In another aspect, the present invention is a sensing system having a surface plasmon resonance sensor disk having grooves extending radially from a center of the disk. In yet another aspect, the present invention is a sensing system including a diffraction anomaly sensor disk having a dielectric layer that varies in thickness. The present invention allows for construction of an inexpensive sensing system that is capable of easily detecting a variety of substances either in a sample or a surrounding environment.

Abstract: A physiological monitor utilizes Faraday rotation measurements to estimate mean photon pathlengths through tissue. These pathlength estimates, along with corresponding optical spectroscopy measurements allow the noninvasive monitoring of blood constituent concentrations. The technique is particularly applicable to noninvasive blood glucose measurements. The physiological monitor has a polarized light source for illuminating tissue and a magnetic field generator which creates a magnetic field within the tissue during illumination. The magnetic field imparts a Faraday rotation in the plane of polarization of the incident light beam as it propagates through the tissue and emerges as a transmitted light beam. A polarimeter is used to measure the rotation of the transmitted light. A signal processor then computes an estimate of the mean pathlength from the polarimeter output.

Abstract: According to the present invention, in a polarimetry for allowing a light to be incident upon a specimen with a spontaneous optical active substance, a polarized light is allowed to be incident upon the specimen while micro-vibrating the plane of vibration; a component having a specific plane of vibration is detected out of the polarized light through the specimen; a component with a certain angular frequency is extracted; and an angle of rotation attributed to the specimen is calculated based on 3 or more groups of data including a relative angle formed between the plane of vibration of the light incident upon the specimen and the plane of vibration of the light, and an intensity of the component with the angular frequency obtained at the relative angle. Consequently, the influence of noises mixed due to bubbles, particles and the like can be eliminated, thereby achieving a stable and highly accurate measurement in a shorter time.

Abstract: A mixing apparatus for preparing from a plurality of materials, preferably powders, in particular components of a pharmaceutical composition, a mixture having a required homogeneity, comprising a non-rotating mixing vessel (7); at least one feeding mechanism for feeding said materials into said vessel (7); a stirring means (31) inside said vessel (7) for preparing said mixture; and at least one measuring device (23) for monitoring in-line at one or more locations in said vessel (7) the homogeneity of the mixture being prepared therein, wherein said at least one measuring device (23) comprises a unit for directing input radiation into said vessel (7), and at least one detector unit (45) for detecting output radiation formed by interaction of said input radiation with said materials in said vessel (7).

Abstract: A method and apparatus for characterizing and screening an array of material samples is disclosed. The apparatus includes a sample block having a plurality of regions for containing the material samples, a polarized light source to illuminate the materials, an analyzer having a polarization direction different than the polarization direction of the polarized light source, and a detector for analyzing changes in the intensity of the light beams. The light source, together with a polarizer, may include a plurality of light beams to simultaneously illuminate the entire array of materials with linearly polarized light so that characterization and screening can be performed in parallel. In addition, the materials in the sample block maybe subjected to different environmental conditions or mechanical stresses, and the detector analyzes the array as a function of the different environmental conditions or mechanical stresses.

Abstract: A real-time optical compensating apparatus reduces the PMD in an optical fiber by determining the principal states of polarization of the optical fiber and delaying one principal state of polarization with respect to the other.

Abstract: Apparatus and methods for measuring the polarization of a received signal. The horizontal and vertical signal components of the incoming signal are coupled to a plurality of channels operating in parallel, each channel having predetermined phase shift values and combining the phase-shifted components so as to produce output signals. One or more parameters of the output signals from each channel are supplied to a processor which determines values of the phase shifts which would yield a null condition, and thereby estimates the polarization of the received signal.