Abstract: An apparatus for measuring pressure in a medium includes a laser for emitting linearly polarized light; a polarizing beam splitter that reflects the linearly polarized light from the laser; a first lens that receives and focuses the linearly polarized light from the polarizing beam splitter; an optical fiber having first and second ends, the first end for receiving the linearly polarized light from the first lens, the second end comprising a tip disposed in the medium, the tip receiving reflected light from the medium, the reflected light being transmitted back through the optical fiber and the first lens to the polarizing beam splitter; the polarizing beam splitter transmitting the reflected light that has polarization orthogonal to the linearly polarized light emitted by the laser but not transmitting the reflected light that has polarization substantially parallel to the linearly polarized light emitted by the laser; a second lens for receiving the reflected light that has polarization orthogonal to the li

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: 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 photodetector device comprising a photosensitive detector (12; 96) and one or more interfaces (20′, 20″, 28, 98) between dissimilar media is configured so that a light beam (LB) for detection will pass through the interface(s) along a beam axis that is not normal to the interface(s). The deviation (&thgr;) from the normal will be such that polarization dependent transmission introduced at the interface(s) will compensate for inherent polarization dependency of the detector (12; 96). The deviation may be achieved by inclining the interface(s) relative to a predetermined direction along which the light beam will be incident. Where the photosensitive detector is in a housing (84) with a window (20) through which the light beam enters the housing, the housing can be tilted. In such as case, there are three interfaces, one (28; 98) at the surface of the detector (12; 96), and one at each surface (20′, 20″) of the window (20).

Abstract: Laser light output from a laser light source is irradiated onto a transmission-type scale. Due to movement of the transmission-type scale, a polarization angle of transmitted light varies in accordance with variations in orientations of half-wave plates arrayed in a longitudinal direction. It is difficult for the polarization angle to be affected by noise factors such as external light or the like. Light intensity of a polarized light component, which is transmitted through an analyzer and detected at a photo-detector, varies in accordance with the polarization angle. Thus, the light intensity varies as the transmission-type scale moves, and a detection signal is output to a movement amount computing device. When an amount of movement is computed on the basis of the signal, the exact amount of movement can be detected.

Abstract: This optical polarimetric detector comprises:

Abstract: Laser light emitted from a laser light source is irradiated onto a transmission-type scale, and is diffracted by a polarization hologram recorded on the transmission-type scale. Only polarization directions of ±1-order diffracted lights, among diffracted lights, are rotated by 90°. The ±1-order diffracted lights interfere with one another such that interference fringes are formed on a light-receiving surface of a photo-detector. Interference light of the ±1-order diffracted lights is transmitted through a polarizing plate. A portion of transmitted light is passed through respective slits of a slit plate and is irradiated onto the photo-detector, and intensity of irradiated light is detected. On the other hand, 0-order diffracted light, ±2-order diffracted lights, and the like, whose polarization directions are not rotated, cannot pass through the polarizing plate, and are blocked before being detected at the photo-detector.

Abstract: According to the present invention, in a simple structure using a fixed analyzer method, in order to measure a smaller PMD value, a predetermined polarization mode dispersion is applied by a reference object to a linearly polarized beam extracted by a first polarizer from a broad band light emitted from a broad band light source. The polarization plane of the light applied with this predetermined polarization mode dispersion is rotated by a polarization plane rotor, and the spectrum of the linearly polarized beam extracted by a second polarizer from the light emitted from the other end side of the measured object is analyzed, thereby to obtain at least one of a maximum value and a minimum value of the polarization mode dispersion.

Abstract: A polarization transformer can be constructed using a continuously adjustable polarization transforming device and a limited-range adjustable polarization transforming device. In general, the response time of the limited-range adjustable polarization transforming device is faster than that of the continuously adjustable polarization transforming device. When the two devices are properly controlled using error signals derived from a transformed optical signal, the polarization state of the optical signal can be adjusted with sufficient speed and without the loss of control associated with reset cycles.

Abstract: A sensor arrangement and system facilitate the measurement of polarized light intensities for use in object identification and classification. In an example embodiment, an imaging sensor for polarizing light from a light source includes an array of light detecting elements that converts light into a plurality of photocurrent signals. The sensor also includes a rotatable disk positioned between a light source and the light detecting array and parallel to the light detecting array. The rotatable disk includes a plurality of linear members that are opaque and parallel to each other that polarize light from the light source passed to the light-detecting array. The sensor further includes a circuit arrangement configured to generate a data set of polarization vector components, the polarization vector components being generated as a function of a set of the photocurrent signals that are sampled as a function of a position of the rotating disk.

Abstract: Techniques for dynamically controlling polarization of an optical signal by combining both feed-forward and feedback controls.

Abstract: A touch panel is constructed of a top sheet member having a resistive membrane on its inner surface and a base sheet member having a resistive membrane on its inner surface, the top and base sheet members facing each other with dot spacers being located in between. The top sheet member is formed by laminating a bulge-resistant film, a polarizing plate, a quarter wavelength plate, and a light isotropic film in this order from above. The base sheet member is constructed of a glass sheet and a reinforcement film whose thermal linear expansion coefficient is almost the same as the thermal linear expansion coefficient of the polarizing plate or the quarter wavelength plate included in the top sheet member, the reinforcement film being adhered to the lower surface of the glass sheet.

Abstract: Apparatus for measuring state of polarization of an input light beam comprises a linear polarizing element (10), e.g. a Glan-Taylor prism, an input fiber and lens (22,24) for directing the input light beam to the linear polarizing element (10), an output stage (26A-26D, 30A-30D, 32A-32D, 34) for receiving the light beam leaving the polarizing element, and at least two waveplates (12A, 12B; 12B, 12C) disposed adjacent each other between the input fiber/lens and the linear polarizing element. Each waveplate has its fast axis oriented at a different predetermined azimuthal angle with respect to the incident light beam. The arrangement is such that first and second portions of the input light beam pass through the linear polarizing element and the two waveplates, respectively, and a third portion of the light beam passes through the linear polarizing element without passing through a waveplate.

Abstract: A phase difference plate (12) converts states of polarization of emergent light form a laser light source (13) and return light form an optical recording medium (5). A diffractive element (21) separates the return light from an optical axis leading from the laser light source (13) to the optical recording medium (5), and guides the return light to a photodetector (14) on the basis of a difference between the states of polarization of the emergent light and the return light. The polarization direction of emergent light from the laser light source (13) is arranged so as to be oriented in the radial direction of the optical recording medium (5) (in the direction of birefringence of the optical recording medium).

Abstract: An optical heterodyne detection system includes an input signal and a local oscillator signal that are combined in an optical coupler and output as a first beam and a second beam. A polarizing beam splitter is optically connected to the optical coupler in order to receive the first beam and the second beam. The polarizing beam splitter includes four outputs for outputting four beams to four photodetectors including two polarized portions of the first beam and two polarized portions of the second beam. The four photodetectors generate four electrical signals in response to respective ones of the four beams. The four electrical signals are transmitted to a processor and processed to provide an output response that is independent of the polarization state of the original input signal and in which the intensity noise has been suppressed.

Abstract: Source light of unknown polarization is input into a polarization controller. The polarization controller transforms the polarization of the source light to a plurality of different polarizations. The transformed source light output by the polarization controller is input to a fixed polarizer, which passes a maximal transmitted intensity of the transformed source light at a given transformation perpendicular to an axis of propagation of the source light. The polarizer passes a minimal transmitted intensity of the transformed source light at a transformation orthogonal to the transformation at which the maximal transmitted intensity is passed. The discriminated transformed source light output by the fixed polarizer is input to a light-wave power meter, which measures the intensity thereof. The maximal and minimal measured transmitted intensities of the discriminated transformed source light can be used to determine the DOP of the source light.

Abstract: A printed circuit board assembly machine inspects circuit boards and parts to be mounted on those circuit boards prior to assembly. This assembly machine may visualize and recognize physical features of the circuit boards and parts as part of this inspection. A filter may be deployed while visualizing certain types of circuit boards or parts to remove characteristic defects found in images of those types of parts. When several types of circuit boards or parts inspected by the assembly machine exhibit different characteristic visualization problems, the assembly machine may deploy a different filter for each type of circuit board or part.

Abstract: The contrast between solder balls and substrate of a Ball Grid Array (BGA) as visualized by a camera of a computer vision system is improved sufficiently to enable reliable recognition in the poor contrast situation when the balls are silver colored and the substrate background is white or light colored by illuminating the BGA with polarized light, and the camera viewing the light reflected from the BGA via a polarization filter oriented to not pass light reflected from the solder balls but to pass light reflected from the substrate.

Abstract: An inexpensive broadband source such as an ASE source, used for erbium amplifier measurements, compares well with the use of a prior art ITU grid. Deltas are less than 0.4 and 0.3 dB for gain and noise figure respectively. The spectral loading used to test erbium amplifiers needs to closely resemble conditions seen in the field. Use of an ITU grid is a good way of achieving this, however it is a costly solution and may restrict the spectral resolution. Use of a high power amplified spontaneous emission source gives a cost-effective alternative, which compares well with ITU grid measurements. In addition the spectral resolution of the measurement is then only limited by the spectral resolution of the optical spectrum analyzer.

Abstract: A combination metrology tool is disclosed which is capable of obtaining both thermal wave and optical spectroscopy measurements on a semiconductor wafer. In a preferred embodiment, the principal combination includes a thermal wave measurement and a spectroscopic ellipsometric measurement. These measurements are used to characterize ion implantation processes in semiconductors over a large dosage range.

Abstract: A band narrowing laser having a band narrowing module which narrows by a band narrowing element a band of the laser beam generated from a laser medium, in which wavefront correction means (10) that corrects the wavefront of an incident laser beam and and projects the corrected beam is intalled in the band narrowing module (6) to produce a laser beam with a narrow and stable spectral line width.

Abstract: Methods and apparatus for detecting objects. In one embodiment, a person entering a secured or “Safe Zone™” is illuminated with low-power polarized radio waves. Differently polarized waves which are reflected back from the person are collected and measured. In a preferred embodiment, concealed weapons are detected by calculating the difference of a pair of differences (Delta A and B) of different polarized reflected energy (upper and lower curves in the two graphs) in the time domain, and by using signal processing methods and apparatus to improve the reliability of the detection process.

Abstract: A magneto-optical effect distance measuring device and measuring rig incorporating the device. The device can measure the distance separating two members which can be displaced one with respect to the other by the magneto-optical effect. A permanent magnet is fixed on one of the members and an electro-optical device is fixed on the other member. The electro-optical device includes a diode emitting an optical beam. Further, a Faraday-effect magneto-optical film is disposed, on the one hand, between a polarizer and an analyser and, on the other hand, in the magnetic field of the magnet when the two members are in proximity to one another, the optical beam passing through the assembly. A diode receives the optical beam retransmitted by the analyzer so as to transform the luminous intensity of the beam into an electrical signal whose amplitude depends on the distance separating the two members when they are in proximity to one another.

Abstract: A method and device for detecting the position of a transparent conveyor belt including directing light beams (2) onto the region of an edge (3) of the conveyor belt, detecting a jump in intensity of the light beam (2, 2′) as a consequence of the partial insertion of the conveyor belt into the beam path (2) and evaluating the detected jump in intensity in order to determine the position of the conveyor belt, wherein the light beams (2) are linear polarized light and the beam path (2) is directed at an angle or irradiation (&agr;) between 40° and 80° of the light (2) onto the bounding surface (7) in such a way that a high degree of reflection is achieved and reflected light and non-reflected light is detected.

Abstract: A system and method for fabricating a polarizer for use in an LCD, which includes cutting said polarizer so that an absorption axis of the polarizer is aligned with an edge of the polarizer by using an optical sensor, coupled to a cutting machine, where the optical sensor uses a rotating reference polarizer to determine a null point of transmission through the polarizer and thereby determine any offset of the absorption axis with respect to an edge of the polarizer.

Abstract: The calibration of a metrology tool with a rotatable polarizer separates the angular dependence of the irradiance from the temporal dependence. The angular dependence of the metrology tool is then modeled, e.g. using a Fourier expansion. The Fourier coefficients are parameterized as a function of wavelength. The actual irradiance, e.g., the reference irradiance and/or back reflection irradiance, is then measured for the metrology tool for one angle of the rotatable polarizer. From the measured irradiance and the modeled angular dependence, the total irradiance of the metrology tool can be determined, which is independent of the angle of the rotatable polarizer. The irradiance, e.g., reference and/or back reflection, can then be determined for any desired angle of the rotatable polarizer using the total irradiance and the angular dependence of the metrology tool.

Abstract: An optical measurement system for evaluating the surface of a substrate or the thickness and optical characteristics of a thin film layer overlying the substrate includes a light source for generating a light beam, a static polarizing element for polarizing the light beam emanating from the light source, and a measurement system for measuring the light reflected from the substrate location. The measurement system includes a static beam splitting element for splitting the light reflected from the substrate into s-polarized light and p-polarized light. The measurement system further includes two optical sensors for separately measuring the amplitude of the s-polarized light and the intensity of the p-polarized light. A control system analyzes the measured amplitude of the s-polarized light and the p-polarized to determine changes in the topography of substrate or changes in the thickness or optical characteristics of the thin film layer.

Abstract: The method and system serve to optically detecting an electric current with an extended measurement range. To that end, two light signals having different wavelengths pass through a Faraday element, the polarization of the two light signals being rotated in each case by at least 0.0014°/A as a function of the electric current. By taking account of both wavelength-dependent polarization rotations, at least one of which lies beyond an unambiguity range, the measurement range is extended distinctly beyond the unambiguity range of each of the two light signals.

Abstract: Detecting a transparent object, in particular a web or conveyor belt of a printing press with at least one radiation source and at least one receiver arrangement for receiving rays from the radiation source, whereby the light intensity change based on the transparent object is independent of the position of the major optical axis h of the transparent object. A particular embodiment envisages two &lgr;/4 small plates, which are each attached to one of two linear polarization filters, which intersect one another.

Abstract: Apparatus and techniques for detecting malfunctions, anomalies and attacks upon optical devices of a transparent all-optical network, including amplified links and optical nodes, of the network. A portion of an input signal of the optical device and a portion of an output signal from the optical device are coupled to an optical processing unit and a an optical to electrical signal converter. The electrical output signal of the converter is coupled to an electronic processing unit which generates a difference signal which is a function of the input and output signal portions for comparison to a predetermined set of parameters. The result of the comparison is an alarm signal indicative of the occurrence of a malfunction. Also described is an optical comparator capable of generating the difference signal which is indicative of perturbations in the optical device.

Abstract: A method and device for automatically controlling a polarizing filter, featuring automatically sensing, measuring, and analyzing at least one parameter associated with direction of a polarizing filter by an electronic direction/motion sensing mechanism, receiving a signal from the electronic direction/motion sensing mechanism relating to the at least one parameter associated with direction of the polarizing filter by a rotation control circuit, and receiving a signal from the rotation control circuit relating to the at least one parameter associated with direction of the polarizing filter by a polarizing filter rotating mechanism for automatically rotating the polarizing filter.

Abstract: A polarized organic photonics device, including an LED or photovoltaic device, is comprised of a first conductive layer or electrode coated with a friction transferred alignment material, a photoactive material, and a second electrically conductive layer or electrode. The alignment material provides for the orientation of the subsequently deposited photoactive material such that the photoactive material interacts with or emits light preferentially along a selected polarization axis. Additional layers and sublayers optimize and tune the optical and electronic responses of the device.

Abstract: The present invention is provided for accurately estimating an amount of angular disagreement of planes of polarization between two polarization-maintaining optical fibers when connecting the polarization-maintaining optical fibers. In the present invention, a distribution of the polarization-maintaining optical fibers by irradiating a light on the lateral side of the polarization-maintaining optical fibers. The positions and heights of peaks of brightness of a transmitted light produced by the irradiated light are varied to comply with the angular disagreement of an axis of polarization which traverses two stress applying sections toward the irradiation direction of the light of each polarization-maintaining optical fiber. The amount of angular disagreement of the planes of polarization can be accurately estimated from the positions and heights of the peaks.

Abstract: According to the present invention, in a simple structure using a fixed analyzer method, in order to measure a smaller PMD value, a predetermined polarization mode dispersion is applied by a reference object to a linearly polarized beam extracted by a first polarizer from a broad band light emitted from a broad band light source. The polarization plane of the light applied with this predetermined polarization mode dispersion is rotated by a polarization plane rotor, and the spectrum of the linearly polarized beam extracted by a second polarizer from the light emitted from the other end side of the measured object is analyzed, thereby to obtain at least one of a maximum value and a minimum value of the polarization mode dispersion.

Abstract: An optical information storage device including a first photodetector for detecting a regenerative signal from reflected light from an optical recording medium, a second photodetector for detecting a tracking error signal and a focusing error signal from the reflected light, and a beam splitter for separating the reflected light into a first beam directed toward the first photodetector and a second beam directed toward the second photodetector. The optical information storage device further includes a phase compensating mechanism provided between the beam splitter and the first photodetector for compensating for a phase difference of the first beam, a Wollaston prism provided between the phase compensating mechanism and the first photodetector for separating the first beam into two beams having orthogonal polarization planes, and a polarization plane rotating mechanism for rotating the polarization plane of the first beam incident on the Wollaston prism.

Abstract: The work piece feeding machine is capable of correctly and efficiently setting a work piece in a through-hole of a carrier. The work piece feeding machine comprises a positioning unit detecting amount of displacement of the work piece with respect to the through-hole and correcting the position of the work piece in the through-hole. The positioning unit includes: a lighting source section provided on the work piece side or the carrier side, the lighting source section throwing polarized light on the work piece and the carrier; a camera provided on the carrier side or the work piece side, the camera receiving the polarized light from the lighting source section so as to catch images of an outer edge of the work piece and an inner edge of the through-hole in a visual field thereof; and an image processing section measuring the amount of displacement on the basis of positions of the outer edge and the inner edge.

Abstract: A signal detector comprises a frequency changing circuit adapted to receive an electric signal having a frequency modulated from a first reference frequency f1 with a modulation width &Dgr;f as input, convert the received electric signal to an electric signal having a second reference frequency f2 lower than the first reference frequency f1 and output the converted electric signal and a frequency/voltage conversion circuit adapted to receive the output of the frequency changing circuit as input and output a voltage corresponding to the ratio of the modulation width &Dgr;f to the second reference frequency f2 and an electric signal having a frequency modulated from a reference frequency Nf2 with a modulation width of N&Dgr;f (N: integer).

Abstract: A nonlinear optical crystal is composed of 2-adamantyl-5-nitorpyridine (AANP) allowing the type 2 phase matching to the sampling light and a measuring object light, emitting a sum frequency light of the measuring object light and the sampling light, with the polarization directions thereof being perpendicular to each other, when the sampling light and measuring object light multiplexed by a multiplexer are entered. When the sum frequency light is emitted through the nonlinear optical crystal, a control portion controls the polarization direction of the sampling light so as to be parallel to a predetermined reference axis located within a plane perpendicular to a phase matching direction of the nonlinear optical crystal. The predetermined reference axis is a single axis maintaining parallelism with the crystal axis of the nonlinear optical crystal even if the wavelength of the inputted light is changed.

Abstract: A method and apparatus for optical wavelength routing separates even and odd optical channels from an input WDM signal. The input beam is first converted to at least one pair of orthogonally-polarized beams. A split-mirror resonator has a front mirror with two regions having different reflectivities, and a reflective back mirror spaced a predetermined distance behind the front mirror. Each of the orthogonally-polarized beams is incident on a corresponding region of the front mirror of the split-mirror resonator. A portion of each beam is reflected by the front mirror, which the remainder of each beam enters the resonator cavity where it is reflected by the back mirror back through the front mirror. The group delay of each reflected beam is strongly dependent on wavelength. The two reflected beams from the resonator are combined and interfere in a birefringent element (e.g., a beam displacer or waveplates) to produce a beam having mixed polarization as a function of wavelength.

Abstract: We have discovered that it is possible to create a beam of light that is polarized in a linear fashion from the illuminator. This beam is directed to the bar coded labels (should not be limited to these only) at a relatively low angle of incidence. The beam is reflected toward the sensor (camera) optics. Before reaching the sensor, it passes through a second polarizing filter which blocks the transmission of the direct specular reflection from the label. The sensor only receives the information from the substrate by the diffuse reflection. The concept was developed specifically with the linerless label stock in mind. However, the present invention can be applied to linerless label sales to UPS and possibly other freight carriers, and/or to other types of labels and surfaces for optical scanning.

Abstract: A rotary motion detection device for measuring the angle of rotation of a rotating shaft is comprised of an illumination source, an optical linear polarizer in the shape of a disk with central aperture there through for the slidable reception of a rotating shaft member, at least one stationary linear polarizer and at least one photodetector. The device is capable of providing absolute position information, infinite resolution of analog signals, ease of installation and environmental tolerance. The subject invention is further of small and light construction, employs a simple electrical interface, direct current supply voltage and offers vastly improved mechanical tolerances over the prior art. Additionally, concentricity of the rotating member, width of the non-contacting gap, axial endplay, runout and perpendicularity of the driving shaft are all inconsequential.

Abstract: Disclosed is a method of evaluating sample system anisotropic refractive indices, and orientations thereof with respect to an alignment surface, in multiple dimensions. The preferred method involves a sequence of steps which allows overcoming mathematical model parameter correlation during mathematical regression parameter evaluation, even though individually, steps of the present invention method wherein anisotropic refractive indices, or differences therebetween, are evaluated, require that only a relatively simple one dimensional data set be acquired.

Abstract: In an optical apparatus comprising a condensing optics (104) for condensing incident light of linearly polarized light (10), an optical splitting element (701) for splitting reflected light reflected by a light reflection member (105) disposed in close proximity of the focal plane of the condensing optics (104) from the incident light, and an optical detection element (704) for detecting a split light beam (12) split by the optical splitting element, an optical rotatory element (103), capable of optically rotating substantially 90° a polarization axis of the linearly polarized light in a region thereof, corresponding to a portion of an effective light beam (11) of the linearly polarized light, available for the condensing optics (104), and also controlling an optical rotatory power thereof by electric signals, is disposed in the optical path of the incident light of the linearly polarized light (10), Further, a linearly polarized light detection element (703) is disposed in the optical path of the split l

Abstract: An encoder having a movable element with a first polarized filter coupled to the movable element. A second polarized filter is either stationary, or moves differently from the first polarized filter. A photo-emitter and photodetector are arranged on opposite sides of the two polarized filters. Thus, when the polarized filters are aligned in phase, a maximum amount of light will penetrate to the photodetector. However, as they become out of phase due to movement of one of the filters, the amount of light will decrease, as a function of the amount of movement.

Abstract: A sensor that measures a difference of currents at two locations along a conductor. The sensor uses two fiber optic current sensors. One current sensor at the first location measures current and has a nulling coil about its sensing loop, which carries current to null out the reading of current. Another current sensor at the second location measures current and also has a nulling coil about its sensing loop. The nulling coil of the latter sensor has the same current as the nulling coil of the sensor at the first location. For similar current sensors sensing the same magnitudes of current at their respective locations will have their outputs nulled to zero.

Abstract: In order to maintain accuracy of measurement, a temperature-insensitive electro-optic probe has a laser diode provided to emit a laser beam based on a control signal of an oscilloscope body, a collimator lens provided to convert the laser beam into a parallel beam; an electro-optic element having on an end face thereof a reflective coating, with the optical characteristics which are changed by propagating an electrical field via a metal pin provided at the end face on the reflective coating side, an isolator provided between the collimator lens and the electro-optic element, and adapted to transmit the laser beam emitted from the laser diode, in order to separate a light reflected by the reflective coating from the laser beam, a photodiode provided to convert the reflected light separated by the isolator into an electrical signal, a temperature detection section arranged to be in contact with optical components consisting the isolator, and to detect the temperature of the optical components and output the res

Abstract: A method and device for automatically controlling a polarizing filter, featuring automatically sensing, measuring, and analyzing at least one parameter associated with direction of a polarizing filter by an electronic direction/motion sensing mechanism, receiving a signal from the electronic direction/motion sensing mechanism relating to the at least one parameter associated with direction of the polarizing filter by a rotation control circuit, and receiving a signal from the rotation control circuit relating to the at least one parameter associated with direction of the polarizing filter by a polarizing filter rotating mechanism for automatically rotating the polarizing filter.

Abstract: An optical measurement system is disclosed for evaluating samples with multi-layer thin film stacks. The optical measurement system includes a reference ellipsometer and one or more non-contact optical measurement devices. The reference ellipsometer is used to calibrate the other optical measurement devices. Once calibration is completed, the system can be used to analyze multi-layer thin film stacks. In particular, the reference ellipsometer provides a measurement which can be used to determine the total optical thickness of the stack. Using that information coupled with the measurements made by the other optical measurement devices, more accurate information about individual layers can be obtained.

Abstract: Apparatus and method for detecting strings attached to bills or other forms of payment in a currency validator. In one implementation a string fraud detection means uses polarized light to detect a string. In another implementation, polarized light and light in a different range of wavelengths are used to detect a string.

Abstract: Accuracy and sensitivity in the optical characterization of solids and solid materials are improved through the use of the interdependent features of: extending the photon energy range over which the metrology is performed to include a portion of the range up through 10 eV, in which, the higher photon energy of the light improves signal distinguishing ability; and providing a controlled ambient in the entire light path between the light source and a detector that prevents absorption and signal definiteness masking so as to sharpen the identifiability of the change parameters imparted into the reflected light. Combinations of specific devices and materials that for different types of ellipsometry are provided.