Optical Patents (Class 324/244.1)
  • Patent number: 8593157
    Abstract: In one aspect, the present invention provides an imager, preferably portable, that includes a source of electromagnetic radiation capable of generating radiation with one or more frequencies in a range of about 1 GHz to about 2000 GHz. An optical system that is optically coupled to the source focuses radiation received therefrom onto an object plane, and directs at least a portion of the focused radiation propagating back from the object plane onto an image plane. The imager further includes a scan mechanism coupled to the optical system for controlling thereof so as to move the focused radiation over the object plane. A detector optically coupled to the lens at the image plane detects at least a portion of the radiation propagating back from a plurality of scanned locations in the object plane, thereby generating a detection signal. A processor that is in communication with the detector generates an image of at least a portion of the object plane based on the detection signal.
    Type: Grant
    Filed: November 9, 2009
    Date of Patent: November 26, 2013
    Assignee: Walleye Technologies, Inc.
    Inventors: Christopher P. Adams, David S. Holbrook
  • Patent number: 8575928
    Abstract: A sensor that includes an actuator having a plurality of actuator magnets. A detector proximate to and mechanically isolated from the actuator defines a bore. A detector magnet inside the bore may move in the bore from a first position to a second position. An optical signal passes through the detector so that the detector magnet blocks the optical signal when the detector magnet is in the first position.
    Type: Grant
    Filed: March 16, 2011
    Date of Patent: November 5, 2013
    Assignee: Transtech of South Carolina
    Inventor: Douglas A. Robertson
  • Patent number: 8575927
    Abstract: A high-resolution sensor of magnetic field sensor system and materials for use in such a system are described. The sensor systems measure a magnetic field using inorganic and/or organic magneto-optically active materials, e.g. polymer material and have an interferometer based on Faraday rotation. The polymer material is preferably in the form of a film. The polymer material has an optical property that is sensitive to the magnetic field, e.g. the Faraday rotation effect. The present invention also provides a sensor head structure comprising the above polymer material. The sensor head may be designed for use with an optical fiber or with mirrors. In particular the present invention provides a fiber Sagnac interferometer to measure the rotation of polarized plane of light. The present invention provides a fiber or mirror based Sagnac interferometer with passive phase bias applied to magnetic field sensing. This invention has the following three major aspects each being an embodiment of the present invention: 1.
    Type: Grant
    Filed: January 16, 2009
    Date of Patent: November 5, 2013
    Assignees: Toyota Jidosha Kabushiki Kaisha, Katholieke Universiteit Leuven
    Inventors: Hitoshi Yamada, Kazuhiro Shintani, Akinobu Fujii, Norio Sato, Thierry Verbiest, Andre Persoons, Pavel Polynkin, Nasser Peyghambarian
  • Publication number: 20130278918
    Abstract: A sensor system for measuring an operating parameter of a wind turbine component is described. The fibre optic sensor system comprises a light source for outputting light in a predetermined range of wavelengths, and an optical fibre comprising a long Fibre Bragg Grating, extending continuously over a length of the optical fibre to provide a continuous measurement region in the optical fibre. The optical fibre is coupled to the wind turbine component such that the continuous measurement region is located at a region of the wind turbine component to be sensed, and such that the grating period at each location in the continuous measurement period is dependent upon the value of the operating parameter at that location. A light detector receives light from the optical fibre, and provides an output signal to the controller indicating the intensity of the received light; based on the detected light, a value for the operating parameter is determined.
    Type: Application
    Filed: November 23, 2011
    Publication date: October 24, 2013
    Applicant: VESTAS WIND SYSTEMS A/S
    Inventors: Lars Glavind, Thomas Hjort, Ib Svend Olesen
  • Patent number: 8547090
    Abstract: A method is disclosed for increasing the sensitivity of a solid state electronic spin based magnetometer that makes use of individual electronic spins or ensembles of electronic spins in a solid-state lattice, for example NV centers in a diamond lattice. The electronic spins may be configured to undergo a Zeeman shift in energy level when photons of light are applied to the electronic spins followed by pulses of an RF field that is substantially transverse to the magnetic field being detected. The method may include coherently controlling the electronic spins by applying to the electronic spins a sequence of RF pulses that dynamically decouple the electronic spins from mutual spin-spin interactions and from interactions with the lattice. The sequence of RF pulses may be a Hahn spin-echo sequence, a Can Purcell Meiboom Gill sequence, or a MREV8 pulse sequence, by way of example.
    Type: Grant
    Filed: December 3, 2008
    Date of Patent: October 1, 2013
    Assignee: President and Fellows of Harvard College
    Inventors: Mikhail D. Lukin, Ronald L. Walsworth, Amir Yacoby, Paola Cappellaro, Jacob M. Taylor, Liang Jiang, Lilian Childress
  • Patent number: 8531183
    Abstract: The control method includes obtaining an assumed angle and an actual angle of each of the plurality of rotation angle detecting members, determining a first rotation angle detecting member, the assumed angle and the actual angle of which differ from each other, determining a second rotation angle detecting member having the actual angle closest to the assumed angle of the first rotation angle detecting member, resetting the given count value of the second rotation angle detecting member to a new count value of the first rotation angle detecting member, changing the actual angle of the first rotation angle detecting member via the new count value of the first rotation angle detecting member to reduce an angular error between the assumed angle and the actual angle of the first rotation angle detecting member.
    Type: Grant
    Filed: February 11, 2011
    Date of Patent: September 10, 2013
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Kyu Tae Kang, Yeong Bae Yeo
  • Patent number: 8525516
    Abstract: This atomic clock comprises means for applying two mutually perpendicular oscillating magnetic fields (9, 10), governed by a control device (5) that makes them apply a static or nearly static magnetic field for compensating the ambient magnetic field in order to cancel sub-level energy variations of the matter, which disrupt the frequency of the returned photons and the reference provided by the clock. Traditional magnetic shielding may be omitted. Said device can also operate as a magnetometer.
    Type: Grant
    Filed: December 10, 2008
    Date of Patent: September 3, 2013
    Assignee: Commissariat à l'énergie atomique et aux énergies alternatives
    Inventors: Matthieu Le Prado, Jean-Michel Leger
  • Patent number: 8525511
    Abstract: A system monitors alternating current and includes a magneto-optical current transducer (MOCT) adapted to modulate an optical signal corresponding to magnitude of the alternating current. Beam splitters are in communication with the MOCT which are in turn connected to respective channels. Each channel includes an LED that is powered by a constant current source.
    Type: Grant
    Filed: December 11, 2007
    Date of Patent: September 3, 2013
    Assignee: ABB Technology AG
    Inventors: Robert M. Synder, Lenny Roland, Robert C. Miller, Anton Poeltl, Michael Mendik
  • Publication number: 20130214773
    Abstract: A gas cell used for a magnetocardiograph that measures a magnetic field generated from a living body (magnetocardiography) and a magnetoencephalograph that measures a magnetic field generated from a brain (magnetoencephalography).
    Type: Application
    Filed: February 14, 2013
    Publication date: August 22, 2013
    Applicant: SEIKO EPSON CORPORATION
    Inventor: SEIKO EPSON CORPORATION
  • Publication number: 20130207649
    Abstract: An optically pumped magnetometer and a magnetic sensing method acquire information as to strengths of magnetic fields in two different directions. A pump light having a circularly polarized component, first probe light having a liner polarized component and second probe light having a linearly polarized component are emitted to a cell containing a group of alkali metal atoms so as to form a crossing region A magnetic field applying unit applies a static magnetic field in a direction of the pump light incident on the crossing region during the emission of the pump light, the first probe light and the second probe light. And, information as to strengths of magnetic fields in two different directions perpendicular to the direction of the static magnetic field in the cell from the rotation angles of a polarization planes of the first and second probe lights during passage through the cell is calculated.
    Type: Application
    Filed: December 21, 2012
    Publication date: August 15, 2013
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: CANON KABUSHIKI KAISHA
  • Publication number: 20130193961
    Abstract: An optical device, a method of configuring an optical device, and a method of using a fiber Bragg grating is provided. The optical device includes a fiber Bragg grating, a narrowband optical source, and at least one optical detector. The fiber Bragg grating has a power transmission spectrum as a function of wavelength with one or more resonance peaks, each comprising a local maximum and two non-zero-slope regions with the local maximum therebetween. The light generated by the narrowband optical source has a wavelength at a non-zero-slope region of a resonance peak that is selected such that one or more of the following quantities, evaluated at the resonance peak, is at a maximum value: (a) the product of the group delay spectrum and the power transmission spectrum and (b) the product of the group delay spectrum and one minus the power reflection spectrum.
    Type: Application
    Filed: January 18, 2013
    Publication date: August 1, 2013
    Applicant: The Board of Trustees of the Leland Stanford Junior University
    Inventor: The Board of Trustees of the Leland Stanford Junior University
  • Patent number: 8493066
    Abstract: A magnetometer is provided for detecting a magnetic field of strength B using the Faraday effect. The magnetometer includes a photon emitter, a first polarizer, a prism, a second polarizer, a detector and an analyzer. The emitter projects an emitted light beam substantially parallel to the magnetic field and having wavelength ?. The prism has an interface surface and is composed of a Faraday medium having Verdet value V. The emitted light beam passes through the first polarizer and then the prism, exiting from the interface surface making an incident angle ?0 to normal of the surface and then refracting into a secondary medium as first and second circularly polarized light beams that are separated by a small angular divergence ?. These polarized light beams have average refraction angle ? to the normal and pass through a post-selection polarizer before the detector measures a weak value Aw of a photon having “which path” operator  associated with the polarized light beams.
    Type: Grant
    Filed: June 6, 2011
    Date of Patent: July 23, 2013
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Allen D. Parks
  • Publication number: 20130154632
    Abstract: There is provided a system (100) for magnetic field detection, comprising a fibre optic interrogator (104) adapted to interrogate a first length of optical fibre (102) with interrogating radiation, detect radiation backscattered from said optical fibre and analyse said detected radiation to provide distributed sensing indicative of mechanical disturbances of said optical, wherein the optic fibre is mechanically coupled to a material whose dimensions vary dependant on applied magnetic field. Changes in dimensions of the optic fibre as can be detected by virtue of changes in back-scattering of light from said fibre using the principles of fibre optic distributed acoustic sensing.
    Type: Application
    Filed: August 31, 2011
    Publication date: June 20, 2013
    Applicant: OPTASENSE HOLDINGS LIMITED
    Inventors: Magnus McEwen-King, David John Hill, Alastair Godfrey
  • Patent number: 8441249
    Abstract: Two transversely poled fibers are disclosed which can be wound around a holder with their poling directions being anti-parallel. A coupling exchanges the polarization directions of the modes of the fibers. Thermally and mechanically caused birefringence changes can thereby be substantially cancelled, while electrical field induced birefringence changes can be added, to provide a more robust high voltage measuring device.
    Type: Grant
    Filed: November 5, 2010
    Date of Patent: May 14, 2013
    Assignee: ABB Research Ltd
    Inventors: Klaus Bohnert, Stephan Wildermuth, Hubert Braendle
  • Patent number: 8432162
    Abstract: A magnetic sensor that measures a magnetic field by using an optical pumping method, the magnetic sensor including: a cell that encloses therewithin atoms or ions each having a single electron in the outermost shell thereof and that is arranged inside the magnetic field; a light source that causes pulsed first linearly polarized light to be incident upon the cell; a circularly polarized light generator that converts a portion of second linearly polarized light, which is the first linearly polarized light having passed through the cell, into elliptically or circularly polarized light and causes the portion of second linearly polarized light to be incident upon the cell; and a polarimeter that detects an angle of rotation of a first polarization plane, which is polarization plane of the first linearly polarized light, and an angle of rotation of a second polarization plane, which is a polarization plane of the second linearly polarized light.
    Type: Grant
    Filed: April 14, 2010
    Date of Patent: April 30, 2013
    Assignee: Seiko Epson Corporation
    Inventor: Kimio Nagasaka
  • Patent number: 8427929
    Abstract: A property, such as a quality parameter, of a write pole in a write head is determined using an optical metrology device, where the write pole is smaller than the optical resolution limit of the metrology device. The metrology device produces polarized light that is reflected off the write pole while the write pole is magnetized either during or after excitation with a write current. The magnetization alters the polarization state of the light, which can be analyzed to transform the altered polarization state into intensity. The intensity of the light is detected over the point spread function of the optics in the metrology device and an intensity value is generated. The intensity value is used to determine the quality parameter of the write pole, e.g., by comparison to a threshold or reference intensity value, which may be generated empirically or theoretically.
    Type: Grant
    Filed: September 7, 2011
    Date of Patent: April 23, 2013
    Assignee: Infinitum Solutions, Inc.
    Inventors: Henry Patland, Juergen Heidmann, Wade A. Ogle, Alexander M. Taratorin
  • Publication number: 20130093419
    Abstract: An apparatus and method of testing a magnetic medium at temperatures of interest is disclosed. Properties of the magnetic medium are determined by focusing light from a source of polarized light on a magnetic surface of the magnetic medium; measuring polarization of resulting reflected light due to the magneto-optical Kerr effect, using, for example a measuring subsystem; and varying the light source to heat the magnetic material where incident to pre-defined temperatures, thereby allowing determination of the magnetic properties using the magneto-optical Kerr effect at said pre-defined temperatures.
    Type: Application
    Filed: June 13, 2011
    Publication date: April 18, 2013
    Applicant: AGENCY FOR SCIENCE, TECHNOLOGY AND RESEARCH
    Inventors: Chengwu An, Kaidong Ye, Qiong Xie, Wendong Song, Kay Siang Tiaw
  • Patent number: 8421455
    Abstract: A magnetometer and concomitant magnetometry method comprising emitting light from a light source, via a pulse generator pulsing light from the light source, directing the pulsed light to an atomic chamber, employing a field sensor in the atomic chamber, and via a signal processing module receiving a signal from the field sensor.
    Type: Grant
    Filed: September 25, 2009
    Date of Patent: April 16, 2013
    Assignees: Southwest Sciences Incorporated, Regents of the University of California
    Inventors: David Christian Hovde, Dmitry Budker, James Higbie, Victor Acosta, Micah P. Ledbetter
  • Publication number: 20130088223
    Abstract: A two-core optical fiber magnetic field sensor is configured from at least a light incidence/emission unit; a lens; a magnetic garnet; and a reflector, wherein the lens and the magnetic garnet are disposed between the light incidence/emission end of the light incidence/emission unit and the reflector; a light beam is emitted from one optical fiber; the light beam is reflected by the reflector after being transmitted through the lens and the magnetic garnet; the light beam is transmitted again through the magnetic garnet and the lens after the reflection; and incident on the other optical fiber, the light beam is emitted again from the other optical fiber, and reflected by the reflector after being transmitted through the lens and the magnetic garnet; and the light beam is transmitted again through the magnetic garnet and the lens after the reflection and incident again on the one optical fiber.
    Type: Application
    Filed: June 23, 2011
    Publication date: April 11, 2013
    Applicant: ADAMANT KOGYO CO., LTD.
    Inventors: Yoshihiro Konno, Masaru Sasaki
  • Patent number: 8405389
    Abstract: An atomic magnetometer includes a light source for a probe beam and a medium in which the probe beam is to be propagated. The medium is a substance which changes a polarization rotation angle of the probe beam depending on a magnetic field intensity at a first measurement position and a magnetic field intensity at a second measurement position different from the first measurement position. The atomic magnetometer directly measures a difference between the magnetic field intensity at the first measurement position and the magnetic field intensity at the second measurement position as a difference in polarization rotation angle, along a propagation path of the probe beam.
    Type: Grant
    Filed: December 26, 2008
    Date of Patent: March 26, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hideyuki Sugioka, Sunao Ichihara
  • Patent number: 8395380
    Abstract: A device for non-destructive control of a component analyzes distribution of a leakage magnetic field emitted by the component when it is subjected to an exciting magnetic field, includes means for generating an exciting magnetic field inside the component to be tested, and means for detecting and measuring the distribution of the magnetic field. The set of means is integrated in a flexible housing to form a device in the form of a flexible coating for being fixed on a region of the surface of the component to be tested. The disclosed embodiments are useful for non-destructive testing of aircraft components, but may also be used in all industrial sectors where testing the integrity of components is important, such as the automotive, railway, marine or nuclear industry.
    Type: Grant
    Filed: May 16, 2007
    Date of Patent: March 12, 2013
    Assignee: Airbus Operations SAS
    Inventor: Marie-Anne de Smet
  • Publication number: 20130038324
    Abstract: An apparatus and system, capable of measuring the magnitude and direction of magnetic fields including an ultra-sensitive, wideband magneto optic (MO) sensor having magneto-optic crystals is disclosed herein. The sensor exploits the Faraday Effect and is based on a polarimetric technique. An ultra sensitivity optical-fiber magneto-optic field sensor measures a magnetic field with minimal perturbation to the field, and the sensor can be used for High-power microwave (HPM) test and evaluation; Diagnosis of radar and RF/microwave devices; Detection/measurement of weak magnetic fields (e.g., magnetic resonance imaging); Characterization of very intense magnetic fields (>100 Tesla, for example rail gun characterization); Detection of very low-frequency magnetic fields; Characterization of a magnetic field over an ultra broad frequency band (DC—2 GHz); Submarine detection; and Submarine underwater communication.
    Type: Application
    Filed: August 11, 2012
    Publication date: February 14, 2013
    Inventors: Dong Ho Wu, Anthony Garzarella
  • Publication number: 20130027030
    Abstract: A magnetic flux sensor for measuring the radial component of the magnetic flux impinging on a stator bar of a high voltage generator. The magnetic flux sensor includes a fiber Bragg grating formed in an optical fiber and enclosed within a magnetostrictive coating. The magnetostrictive coating responds to changes in magnetic flux by applying a strain on the fiber that changes the reflected wavelength of the Bragg grating that can be measured to provide a measurement of the flux. In one embodiment, one or more of the magnetic flux sensors is positioned directly within an insulating layer of the particular stator bar.
    Type: Application
    Filed: July 27, 2011
    Publication date: January 31, 2013
    Inventors: Michael Twerdochlib, Erik Abromitis
  • Patent number: 8362762
    Abstract: A magnetic field measurement device includes: a magneto-optical sensor that measures a first axial component of a magnetic field in the direction of a first axis that is arbitrarily set in the magnetic field that is to be measured; and a second magneto-optical sensor that measures a second axial component of the magnetic field in the direction of a second axis that form an angle q (0<q<90°) with the first axis.
    Type: Grant
    Filed: March 16, 2010
    Date of Patent: January 29, 2013
    Assignee: Seiko Epson Corporation
    Inventor: Ryuji Hokari
  • Publication number: 20130002245
    Abstract: The present invention relates to a vector magnetometer for measuring the components of an ambient magnetic field. This vector magnetometer comprises an optically pumped scalar magnetometer (2?), a pair of conductive windings (Ex,Ey) having distinct axes (Ox, Oy) and powered by two generators (Gx, Gy) having distinct frequencies. The RF coil (56) of the scalar magnetometer and the conductive windings (Ex,Ex) are mechanically integral with a swivel support (85) mounted on swivel means. The axis of the RF coil is in the same plane as the axes Ox, Oy. The support is swivelled so that this plane is substantially orthogonal to the ambient magnetic field.
    Type: Application
    Filed: June 28, 2012
    Publication date: January 3, 2013
    Applicant: Commissariat a I'energie atomique et aux ene alt
    Inventors: Thomas JAGER, Jean-Michel LEGER
  • Publication number: 20120313634
    Abstract: A magnetometer is provided for detecting a magnetic field of strength B using the Faraday effect. The magnetometer includes a photon emitter, a first polarizer, a prism, a second polarizer, a detector and an analyzer. The emitter projects an emitted light beam substantially parallel to the magnetic field and having wavelength ?. The prism has an interface surface and is composed of a Faraday medium having Verdet value V. The emitted light beam passes through the first polarizer and then the prism, exiting from the interface surface making an incident angle ?0 to normal of the surface and then refracting into a secondary medium as first and second circularly polarized light beams that are separated by a small angular divergence ?. These polarized light beams have average refraction angle ? to the normal and pass through a post-selection polarizer before the detector measures a weak value Aw of a photon having “which path” operator  associated with the polarized light beams.
    Type: Application
    Filed: June 6, 2011
    Publication date: December 13, 2012
    Applicant: United States Government, as represented by the Secretary of the Navy
    Inventor: Allen D. Parks
  • Patent number: 8314612
    Abstract: A compact narrow band imaging system includes a vapor cell having a gas that receives and transmits light in accordance with the Faraday effect. A magnetic source is provided for applying a magnetic field to the vapor cell. Crossed polarizers are disposed before and after the vapor cell creating a Faraday optical filter. The only light that passes through the filter is light within a narrow band near the absorption peaks of the vapor. Other optical elements of the imaging system including filters, image detectors, electron multipliers, signal digitizers, and heat filters are co-located within the imaging system's common thermal isolation container to provide improved performance. The compact system is suitable for wide area surveillance, including daylight surveillance for combustion sources such as forest fires and missile exhaust.
    Type: Grant
    Filed: January 11, 2008
    Date of Patent: November 20, 2012
    Inventors: Wayne Eugene Rodgers, Lawrence Scott Ring
  • Publication number: 20120286775
    Abstract: A system and method for fiber magneto-optic detection are provided, which belongs to the optical application field. The system comprises: a reference device (300) for generating a reference magnetic field signal with known amplitude and shape at a measurement point; a magneto-optic probe (100) for detecting a magnetic field signal of the measuring point, converting the magnetic field signal into an optical signal, and transmitting to a power supply and signal processing module (400) the optical signal sent by the magneto-optic probe; the power supply and signal processing module (400) for transmitting laser light, and converting the optical signal into an electrical signal after receiving it, and demodulating and analyzing the electric signal to acquire the magnetic field information and/or the current information of the measuring point.
    Type: Application
    Filed: November 22, 2010
    Publication date: November 15, 2012
    Applicant: 3S HI-TECHNOLOGIES CO., LTD.
    Inventor: Haijun Yuan
  • Publication number: 20120274321
    Abstract: A system for fiber DC magneto-optic detection and method thereof are provided. The system comprises a power supply and signal processing module (400), an optical fiber device (200), a magneto-optic probe (100) and a reference device (300). The reference device (300) is mounted in the system, and the measured signal can be corrected via a reference magnetic field pulse signal generated by the reference device (300) so as to eliminate the influence that the environmental factors caused on the measurement, and to obtain accurate measurement data, thus improving measurement accuracy of the system.
    Type: Application
    Filed: November 22, 2010
    Publication date: November 1, 2012
    Inventor: Haijun Yuan
  • Patent number: 8283622
    Abstract: A method and apparatus for testing a magnetic medium. The method comprises applying a magnetic field of a time-varying strength; directing a polarized optical beam towards a portion of the medium that is in the magnetic field, wherein the optical beam is reflected by a surface of the medium at a point of incidence in the magnetic field; moving the medium relative to the optical beam so as to cause the point of incidence to repeatedly traverse each of a plurality of sectors along a track on the surface; obtaining a series of Kerr signal measurements of the reflected optical beam; grouping measurements into ensembles such that the measurements in an individual ensemble are those obtained while the point of incidence was in a corresponding one of the sectors; and determining at least one magnetic property of at least one of the sectors from the measurements in the corresponding ensemble.
    Type: Grant
    Filed: August 13, 2008
    Date of Patent: October 9, 2012
    Assignee: Agency for Science, Technology and Research
    Inventors: Chengwu An, Kaidong Ye
  • Publication number: 20120209546
    Abstract: The present invention relates to a new method for characterizing magnets, magnetic assemblies (combinations of magnets) and magnetic materials. In what follows, these will be called under the common term ‘magnetic systems’. The method is based on obtaining quantitative properties of the magnetic system by combining magnetic field measurement data and theoretical modeling or simulation data. The input parameters of the theoretical model are optimized using an optimization method in order to obtain a best fit to the measured data. In this method, the present invention involves precalculating magnetic field distributions prior to the optimization execution in order to considerably speed up the process. Combining this advanced data processing with fast magnetic field mapping using e.g. a magnetic field camera, allows real-time measurement and data analysis of magnetic systems for applications in e.g. quality control of such magnetic systems.
    Type: Application
    Filed: February 13, 2012
    Publication date: August 16, 2012
    Inventor: Koen Jozef Theo VERVAEKE
  • Publication number: 20120206135
    Abstract: A production method of a gas cell includes: forming a coating layer on a surface of a plate material; assembling a plurality of the plate materials having the coating layer formed thereon so as to form a cell surrounded by the surface having the coating layer formed thereon; and filling the formed cell with an alkali metal gas.
    Type: Application
    Filed: February 15, 2012
    Publication date: August 16, 2012
    Applicant: Seiko Epson Corporation
    Inventors: Kimio NAGASAKA, Kazumichi KIKUHARA
  • Patent number: 8228059
    Abstract: Provided is a method of evaluating properties of ferrite which can continuously measure change in magnetic properties accompanying change in composition of the ferrite merely by preparing one specimen. A composition gradient ferrite thin film constituted of a plurality of composition gradient ferrite layers which are formed by inclining component composition in the horizontal direction is formed on a single crystal substrate having light transmitting property using a thin film forming method, and a magneto-optical effect is continuously measured along the composition gradient direction of the ferrite thin film whereby change in magnetic properties accompanying a change in composition of the ferrite is continuously measured also provided is a method of evaluating properties of ferrite which can continuously measure change in magnetic properties accompanying change in composition of the ferrite merely by preparing one specimen.
    Type: Grant
    Filed: March 12, 2010
    Date of Patent: July 24, 2012
    Assignees: JFE Mineral Company, Ltd., Tohoku University
    Inventors: Yosuke Iwasaki, Masashi Kawasaki, Tomoteru Fukumura
  • Patent number: 8159216
    Abstract: This eddy current imaging method includes the steps of: positioning (72), in the vicinity of a large inspection region, elements for the measurement of a surface magnetic field, generating (74, 92) a global exciting magnetic field over the observation inspection region, measuring (76, 84) a resultant magnetic field at the surface, in the form of images, processing (90) the images. The generating step (74, 82) involves generating a set of at least two exciting magnetic field waveforms; the measuring step (76, 86) involves measuring a set of configurations of the resultant magnetic field in the form of images; the step (90) of treating the images by combining them allows defects to be detected and the position and the nature thereof to be determined.
    Type: Grant
    Filed: May 10, 2007
    Date of Patent: April 17, 2012
    Assignee: Centre National de la Recherche Scientifique (C.N.R.S.)
    Inventors: Pierre-Yves Joubert, Yohan Le Diraison, Jean Pinassaud
  • Publication number: 20120086443
    Abstract: A fiber optic strain and temperature sensor is disclosed. The fiber can directly measure strain and temperature or the fiber can be coated with a magnetostrictive coating to measure magnetic flux, or coated with a hydroscopic coating to measure humidity or moisture content. The optical fiber sensors can be embedded in different locations in a generator to provide real time measurement of operating conditions.
    Type: Application
    Filed: July 1, 2011
    Publication date: April 12, 2012
    Inventor: Michael L. Bazzone
  • Patent number: 8138756
    Abstract: A magnetometer includes a tapered microfiber having a curved portion, an excitation laser in optical communication with the tapered microfiber, and a nanocrystal attached to the curved portion of the tapered microfiber. Laser light emitted from the excitation laser interacts with the nanocrystal to create an emitted photon flux which is monitored to detect a magnetic field passing through the nanocrystal.
    Type: Grant
    Filed: April 24, 2009
    Date of Patent: March 20, 2012
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Paul E. Barclay, Raymond G. Beausoleil, Kai-Mei Camilla Fu, Charles M. Santori, Marco Fiorentino
  • Patent number: 8125644
    Abstract: An optically sensitive device includes a material that changes dimension in response to a change in a magnetic field. In an embodiment, the optically sensitive device is configured to measure a change in a magnetic field as a function of the change of dimension of the material.
    Type: Grant
    Filed: December 15, 2008
    Date of Patent: February 28, 2012
    Assignee: Raytheon Company
    Inventor: Devon G. Crowe
  • Patent number: 8120355
    Abstract: A magnetic anomaly detector includes a magnetically active device which produces analog signals in response to magnetic fields. The analog signals are time quantized and then discrete-time differentiated. The differentiated signals are applied to a low-pass filter. The filtered signals are Fourier transformed into an amplitude-frequency spectrum. An error detector compares at least one reference amplitude-frequency spectrum with the reference spectrum to identify the presence or absence of a magnetic anomaly. The resulting error is displayed on a monitor or operates an alarm.
    Type: Grant
    Filed: May 27, 2009
    Date of Patent: February 21, 2012
    Assignee: Lockheed Martin Corporation
    Inventor: John B. Stetson
  • Patent number: 8106653
    Abstract: System and methods are provided for optical-magnetic Kerr effect signal analysis. In one aspect, a test fixture is supplied having parallel conductive lines, with an input of a first line adjacent a resistively loaded output of a second line and a resistively loaded output of the first line adjacent an input of the second line. An optically transparent test region is interposed between the conductive lines, and a metallic reflector underlies the test region. A signal reference is supplied to the input of the first line and a signal under test is supplied to the input of the second line. A light beam having a first angle of polarization is focused through the test region onto the reflector. The intensity of the reflected light is measured and the similarity between the signal under test and the reference signal can be determined in response to the measured light intensity.
    Type: Grant
    Filed: May 14, 2009
    Date of Patent: January 31, 2012
    Assignee: Applied Micro Circuits Corporation
    Inventor: Joseph Martin Patterson
  • Publication number: 20120001625
    Abstract: A high-resolution sensor of magnetic field sensor system and materials for use in such a system are described. The sensor systems measure a magnetic field using inorganic and/or organic magneto-optically active materials, e.g. polymer material and have an interferometer based on Faraday rotation. The polymer material is preferably in the form of a film. The polymer material has an optical property that is sensitive to the magnetic field, e.g. the Faraday rotation effect. The present invention also provides a sensor head structure comprising the above polymer material. The sensor head may be designed for use with an optical fiber or with mirrors. In particular the present invention provides a fiber Sagnac interferometer to measure the rotation of polarized plane of light. The present invention provides a fiber or mirror based Sagnac interferometer with passive phase bias applied to magnetic field sensing. This invention has the following three major aspects each being an embodiment of the present invention: 1.
    Type: Application
    Filed: January 16, 2009
    Publication date: January 5, 2012
    Applicants: KATHOLIEKE UNIVERSITEIT LEUVEN, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Hitoshi Yamada, Kazuhiro Shintani, Akinobu Fujii, Norio Sato, Thierry Verbiest, Andre Persoons, Pavel Polynkin, Nasser Peyghambarian
  • Publication number: 20110305890
    Abstract: Provided is a method of evaluating properties of ferrite which can continuously measure change in magnetic properties accompanying change in composition of the ferrite merely by preparing one specimen. A composition gradient ferrite thin film constituted of a plurality of composition gradient ferrite layers which are formed by inclining component composition in the horizontal direction is formed on a single crystal substrate having light transmitting property using a thin film forming method, and a magneto-optical effect is continuously measured along the composition gradient direction of the ferrite thin film whereby change in magnetic properties accompanying a change in composition of the ferrite is continuously measured.
    Type: Application
    Filed: March 12, 2010
    Publication date: December 15, 2011
    Applicants: Tohoku University, JFE Mineral Company, Ltd.
    Inventors: Yosuke Iwasaki, Masashi Kawasaki, Tomoteru Fukumura
  • Publication number: 20110279114
    Abstract: The present invention provides a magnetic biosensor device comprising a sensor cartridge for receiving an assay to be tested, an electromagnetic unit for producing a magnetic field at a sensor surface of the sensor cartridge, and detection means for detecting the presence of magnetic particles close to the sensor surface. The electromagnetic unit is adapted to periodically produce a magnetic field having at least a first and a second magnetic field strength, the ratio of the amount of time of applying the first magnetic field strength to the amount of time of the period of applying the first and the second field strength being varied during the measurement. The invention further provides a method for applying a magnetic field to a sensor surface of a magnetic bio sensor device.
    Type: Application
    Filed: April 9, 2009
    Publication date: November 17, 2011
    Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.
    Inventors: Hans Van Zon, Mykhaylo Ovsyanko
  • Patent number: 8058869
    Abstract: The device includes two supports and a primary conductive strip. The primary conductive strip includes a neutral surface, a first side, and a second side. The primary conductive strip is connected one of directly and indirectly on the first side to the two supports such that the primary conductive strip is constrained in two dimensions and movable in one dimension. The device also includes a primary distributed feedback fiber laser. The primary distributed feedback fiber laser includes a fiber axis. The primary distributed feedback fiber laser is connected to the primary conductive strip along one of the first side and the second side such that there is a positive distance between the neutral surface of the primary conductive strip and the fiber axis of the primary distributed feedback fiber laser.
    Type: Grant
    Filed: October 21, 2008
    Date of Patent: November 15, 2011
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Geoff A Cranch, Gordon M. A. Flockhart
  • Publication number: 20110267049
    Abstract: An optical fiber magneto-optical detecting device comprises: a light-guiding input part (10) used for importing polarized light; a Faraday magneto-optical rotator (2), which is a magneto-optical crystal and used for affecting the intensity of the polarized light depending on a change of a magnetic field; a light-guiding output part (30) for exporting the polarized light; and a compensation unit (1a, 1b) used for rotating the imported polarized light, thus avoiding near-zero desensitization, and for compensating the temperature error of the magneto-optical crystal. The compensation unit (1a, 1b) is provided between the light-guiding input part (10) and the Faraday magneto-optical rotator (2) or between the Faraday magneto-optical rotator (2) and the light-guiding output part (30).
    Type: Application
    Filed: December 31, 2009
    Publication date: November 3, 2011
    Inventor: Haijun Yuan
  • Publication number: 20110193555
    Abstract: An atomic magnetometer includes a light source for a probe beam and a medium in which the probe beam is to be propagated. The medium is a substance which changes a polarization rotation angle of the probe beam depending on a magnetic field intensity at a first measurement position and a magnetic field intensity at a second measurement position different from the first measurement position. The atomic magnetometer directly measures a difference between the magnetic field intensity at the first measurement position and the magnetic field intensity at the second measurement position as a difference in polarization rotation angle, along a propagation path of the probe beam.
    Type: Application
    Filed: December 26, 2008
    Publication date: August 11, 2011
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Hideyuki Sugioka, Sunao Ichihara
  • Publication number: 20110169487
    Abstract: An optical fiber type magnetic field sensor having a light source, an incident side optical fiber guiding light from the light source, a polarizer linearly polarizing the light outgoing from the incident side optical fiber, a first Faraday rotator rotating polarization of the linearly polarized light by an intensity of an external magnetic field; an optical receiver, based on the polarization-rotated light, performing a photoelectric conversion to output the light as an electrical signal; a processor processing the electrical signal to output the intensity of the external magnetic field as an output voltage value; a second Faraday rotator and a permanent magnet further providing a certain non-90n degree (where n is an integer) polarization rotation angle, to a polarization rotation angle of light outgoing from the first Faraday rotator, with respect to a polarization axis of the polarizer; and a mirror.
    Type: Application
    Filed: January 5, 2011
    Publication date: July 14, 2011
    Applicant: MITUTOYO CORPORATION
    Inventor: Yutaka MIKI
  • Publication number: 20110163743
    Abstract: This three-layer magnetic element comprises, on a substrate, a first oxide, hydride or nitride layer O having a metal magnetic layer M mounted thereon, the latter having either a second oxide, hydride or nitride layer O?, or a non-ferromagnetic metal layer M? mounted thereon. Layer M is continuous, has a thickness of 1 to 5 nm and the magnetisation thereof is parallel to the layer plane in the absence of layers O and O?. There is, for a range of temperature equal to or greater than ambient temperature, interfacial magnetic anisotropy perpendicular to the layer plane on interfaces O/M and M/O? that is capable of decreasing the effective demagnetising field of layer M or orienting the magnetisation of layer M in a manner substantially perpendicular to the layer plane.
    Type: Application
    Filed: October 13, 2010
    Publication date: July 7, 2011
    Applicants: Commissariat A L'Energie Atomique Et Aux Energie Alternatives, Centre National De La Recherche Scientifique
    Inventors: Bernard RODMACQ, Stéphane AUFFRET, Bernard DIENY, Lavinia Elena NISTOR
  • Publication number: 20110152703
    Abstract: A system includes at least one first magnetic field sensor configured to measure first and second magnetic fields. The system also includes at least one second magnetic field sensor configured to measure the second magnetic field substantially without measuring the first magnetic field. The system further includes processing circuitry configured to perform signal cancellation to generate measurements of the first magnetic field and to generate an output based on the measurements of the first magnetic field. The sensors could represent magneto-electric sensors. The magneto-electric sensors could be configured to up-convert electrical signals associated with the first and/or second magnetic fields to a higher frequency. The processing circuitry could be configured to identify one or more problems associated with a patient's heart.
    Type: Application
    Filed: November 9, 2010
    Publication date: June 23, 2011
    Applicant: NATIONAL SEMICONDUCTOR CORPORATION
    Inventors: Lawrence H. Zuckerman, Michael X. Maida, Dennis M. Monticelli, James B. Wieser, Jamal Ramdani, Paul Mawson, Moulay Mohamed Ibourk
  • Publication number: 20110144472
    Abstract: A method for holographic imaging an object having density and/or magnetization is described, the object being located in an examined medium using potential field data including but not limited to gravity and/or magnetic total field and/or vector and/or tensor data. The potential field sensors may measure the gravity and/or magnetic total field and/or vector and/or tensor data at least one receiving position with respect to the examined medium. At least one component of the measured potential field in at least one receiver location (potential field data) may be used as at least one artificial source of the potential field data. Artificial sources may produce a back-propagating (migration) field. An integrated sensitivity of the potential field data to density and/or magnetization perturbation may be calculated. A spatial weighting of at least one of the back-scattering (migration) fields may form a potential field holographic image.
    Type: Application
    Filed: September 10, 2010
    Publication date: June 16, 2011
    Applicant: TECHNOIMAGING, LLC
    Inventor: Michael S. Zhdanov
  • Publication number: 20110101974
    Abstract: A beam that passes through a plurality of gas cells a number of times is led to a deflection meter from a light ejecting section, detection of a deflected surface angle is performed and a strength of a magnetic field is measured by a structure in which the plurality of the gas cells is arranged along a light beam between two reflection units or light concentrating units that have a light beam incidence section and a light beam ejecting section and are opposite to each other, and a laser beam that is incident from the light beam incidence section passes through the plurality of the gas cells and then is multiply reflected by both reflection units.
    Type: Application
    Filed: October 28, 2010
    Publication date: May 5, 2011
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Kimio NAGASAKA