Abstract: A fiber cell includes: an optical fiber including a cladding that totally reflects light, a core through which the totally reflected light propagates, and an internal cavity formed in the core; and an alkali metal atom sealed in the internal cavity.

Abstract: A Faraday rotator mirror which is compact, allows high workability of manufacturing and has high reliability and high coupling efficiency is provided. The Faraday rotator mirror comprises a graded-index fiber, a Faraday rotator and a reflector mirror, wherein light incident via the graded-index fiber passes through the Faraday rotator to be reflected on the reflector mirror, and the reflected light passes through the Faraday rotator and emerges through the graded-index fiber.

Abstract: A magnetic sensor is provided that measures a magnetic field. The sensor includes a first gas, a probe light source which causes first circular polarized light to be incident on the first gas, a second gas arranged on an optical path of a second circular polarized light, an AC magnetic field generator which generates an AC magnetic field and generates magnetic resonance, a bias magnetic field generator which generates bias magnetic fields with different intensities for the first gas and the second gas and differentiates the optical transmittance of the first circular polarized light in the first gas from the optical transmittance of the second circular polarized light in the second gas, and a detector which detects a light amount of the first circular polarized light and a third circular polarized light.

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.

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.

Abstract: A magnetometer for sensing a magnetic field may include a solid state electronic spin system, and a detector. The solid state electronic spin system may contain one or more electronic spins that are disposed within a solid state lattice, for example NV centers in diamond. The electronic spins may be configured to receive optical excitation radiation and to align with the magnetic field in response thereto. The electronic spins may be further induced to precess about the magnetic field to be sensed, in response to an external control such as an RF field, the frequency of the spin precession being linearly related to the magnetic field by the Zeeman shift of the electronic spin energy levels. The detector may be configured to detect output optical radiation from the electronic spin, so as to determine the Zeeman shift and thus the magnetic field.

Abstract: The present invention relates to a method and system for high spatial resolution measurement of a magnetic field or gradient. The method determines Zeeman polarization at a submicron distance from cell surfaces of an optical pumping cell using two laser beams. A strong pump beam produces Zeeman polarization in the vicinity of surfaces inside the optical pumping cell. The Zeeman polarization precesses around the magnetic field that is to be measured and is probed by the evanescent wave of a weak probe beam. The precessing Zeeman polarization can be monitored by measuring reflectivity of the probe beam at an interface between the active medium and the cell. The polarization can be used to measure the magnetic field or gradient. In one embodiment a second probe beam in the yz-plane is incident on the same position as the pump beam and the first probe beam that is in the xz-plane. Both probe beams undergo total internal reflection at an interface between the cell surface and the active medium.

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.

Abstract: An atomic magnetometer is disclosed which utilizes an optical cavity formed from a grating and a mirror, with a vapor cell containing an alkali metal vapor located inside the optical cavity. Lasers are used to magnetically polarize the alkali metal vapor and to probe the vapor and generate a diffracted laser beam which can be used to sense a magnetic field. Electrostatic actuators can be used in the magnetometer for positioning of the mirror, or for modulation thereof. Another optical cavity can also be formed from the mirror and a second grating for sensing, adjusting, or stabilizing the position of the mirror.

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.

Abstract: The invention concerns a device and a method for examining magnetic properties of objects, in particular of sheet material such as for example bank notes. Therein the invention proceeds from a device and a method for examining magnetic properties of objects with a magneto-optical layer having magnetic domains, the optical properties of the magneto-optical layer being influenced by the magnetic properties of the object to be examined, at least one light source for the generation of light incident upon the magneto-optical layer, and at least one sensor for the reception of light which is transmitted and/or reflected by the magneto-optical layer, with a magnetic filed in the area of the magneto-optical layer which extends substantially parallel to the surface of the magneto-optical layer.

Abstract: A magnetic field sensor which has a simple configuration and is capable of detecting a magnetic field with high sensitivity, including a vessel containing a dispersion in which magnetic particles are dispersed, a light source which irradiates the vessel with light, and light intensity measurement means arranged on an opposite side of the vessel from the light source for measuring the intensity of transmitted light having passed through the vessel, as needed.

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.

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.

Abstract: Micromagnetic elements, logic devices and methods of fabricating and using them to store data and perform logic operations are disclosed. Micromagnetic elements for data storage, as well as those providing output from a logic device, are at least partially covered with an optical coating that facilitates determination of the magnetic state. The disclosed logic devices perform one or more of AND, OR, NAND and NOR operations.

Abstract: A method and system for detecting magnetic nanoparticles include measuring a magneto-optical enhancement of the plasmon absorption in the optical response.

Abstract: A polarization microscope optically detects the effect of the magnetic field from a sub-optical resolution magnetic structure on a magneto-optical transducer. The magneto-optical transducer includes a magnetic layer with a magnetization that is changed by the magnetic field produced by the magnetic structure. The saturation field of the magnetic layer is sufficiently lower than the magnetic field produced by the magnetic structure that the area of magnetization change in the magnetic layer is optically resolvable by the polarization microscope. A probe may be used to provide a current to the sample to produce the magnetic field. By analyzing the optically detected magnetization, one or more characteristics of the sample may be determined. A magnetic recording storage layer may be deposited over the magnetic layer, where a magnetic field produced by the sample is written to the magnetic recording storage layer to effect the magnetization of the magnetic layer.

Abstract: A magnetic sensing method comprises irradiating a pump light having a circularly polarized component and a probe light having a linearly polarized component onto a group of atoms contained in a cell so as to make the lights produce an intersection region and detecting a change of rotation angle of a plane of polarization of the probe light before and after passing the cell. The pump light and the probe light are irradiated in a state where a magnetic field of the direction in which the pump light strikes the intersection region is provided with a gradient.

Abstract: A magnetic probe includes a tubular container, the inside of which can be observed and at least one end of which is closed, a paramagnetic seed which is fixed to an end of the tubular container, and a paramagnetic colloidal particle dispersion liquid that is filled in the tubular container.

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.

Abstract: Provided is a highly accurate optical pumping magnetometer, in which a static magnetic field and an oscillating field to be applied to a vapor cell are stabilized. To this end, the optical pumping magnetometer includes: Helmholtz coils for applying a constant static magnetic field to a vapor cell serving as a magnetic field detector; fluxgate magnetometers for detecting environmental magnetic noise in two directions of X-axis direction and Y-axis direction other than Z-axis direction which is a direction for detecting a magnetic field coming out of a measurement object while locating the vapor cell in the center thereof; magnetometer drive circuits for driving the fluxgate magneotometers; current converters for converting outputs of the magnetometer drive circuits into amount of currents; and magnetic field generating coils for generating a magnetic field in a phase opposite to the environmental magnetic noise in the two directions.

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.

Abstract: A magnetometer is provided comprising an atomic vapor in an enclosure, a source of light for preparing the vapor into a state exhibiting electromagnetically induced transparency, a first laser beam passing through the atomic vapor, a phase detector for detecting changes in phase of the first laser beam, and a controller which controls the light source and laser beam and receives the information detected by the phase detector in order to compute from those changes in phase a magnetic field strength in the presence of a selected background magnetic field of at least 0.001 T. Operation in the presence of a background field helps make this magnetometer suitable for diagnostic imaging applications.

Abstract: A magneto-optic sensor for oilfield application, the sensor (1, 1?, 101, 101?) receives an incident beam IB, IBA, IBB, IBC, IBD and comprises a polarizing element (3, 103) for providing a determined state of polarization beam and a Faraday rotator (4, 104) for providing a response beam having a modified state of polarization. The sensor provides a response beam (RB, RBA, RBB, RBC, RBD having an intensity dependent on an external magnetic field representative of a particular characteristic of a well-bore casing CC, CR applied on the Faraday rotator (4, 104).

Abstract: [Problem] To permit reduction in the temperature dependence of a sensor, which is ascribable to the temperature dependence of the Verdet constant of a sensor fiber, at a low cost. [Means for Resolution] In a prior-art optical sensor fiber of reflection type, reduction in the temperature dependence of a sensor is coped with by, e.g., duplexing a signal processing circuit and a receiving optical system, so as to execute the mean processing of modulation signals, whereas in this invention, the elimination of the temperature dependence of a modulation signal is realized by selecting a ferromagnetic Faraday rotor 13 so that a modulation degree (Sout) expressed by the ratio between an AC component and a DC component may become constant or within a certain range, so as to especially simplify a configuration and to attain a lower cost.

Abstract: An electric field sensor is obtained by directly forming an electrooptical film of Fabry-Perot resonator structure on a polished surface at a tip of an optical fiber by an aerosol deposition method.

Abstract: A method of measuring at least one property including a magnetic property of target material is provided. The method includes the step of generating a pump pulse train having one or more pump pulses at a repetition rate along a first propagation path, each pump pulse having a pulse energy density, a laser wavelength within a range of laser wavelengths, and a pulse duration The method further includes the step of irradiating the target material with at least a portion of the one or more pump pulses focused into at least one spot having a spot shape and size so as to cause transient perturbation in the target material. The method still further includes the step of generating at least one probe pulse train having one or more probe pulses at a repetition rate along a second propagation path, each probe pulse having a pulse energy density, a laser wavelength within a range of laser wavelengths, and a pulse duration.

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.

Abstract: A flaw detection apparatus includes a coil for producing an alternating-current magnetic field for flowing eddy currents in a magnetic material; a magneto-optical element disposed at the center of an inner peripheral portion of the coil and having a reflective film at an end face thereof opposed to the face of the member to be flaw-detected; an optical fiber for entering light from a light source into the magneto-optical element toward the reflective film via a circulator; an optical fiber for entering reflected light reflected by the reflective film into an analyzer via the circulator; a photoelectric conversion element for converting output light of the analyzer into an electrical signal; and a computing device for processing an output signal of the photoelectric conversion element and detecting a flaw of the member to be flaw-detected, based on the rotation angle of the plane of polarization of the reflected light.

Abstract: An atomic magnetometer that simultaneously achieves high sensitivity, simple fabrication and small size. This design is based on a diverging (or converging) beam of light that passes through an alkali atom vapor cell and that contains a distribution of beam propagation vectors. The existence of more than one propagation direction permits longitudinal optical pumping of atomic system and simultaneous detection of the transverse atomic polarization. The design could be implemented with a micro machined alkali vapor cell and light from a single semiconductor laser. A small modification to the cell contents and excitation geometry allows for use as a gyroscope.

Abstract: Providing: quickly brining a vapor cell 119 to a desired temperature when retaining the heat of the vapor cell 119 to enhance the magnetic field detection performance of an optically pumped magnetometer; preventing adherence of atoms in the vapor cell 119 to a laser irradiation light passing-through part of the vapor cell 119; downsizing the periphery of the vapor cell 119; and suppressing the effect of a magnetic field from a heater used to retain the heat of the vapor cell 119.

Abstract: A system for lightning detection is provided. The lightning detection system includes a conductor configured to receive a lightning strike and transmit a lightning induced current. The system also includes a fiber optic current sensor configured to detect multiple lightning parameters from the lightning induced current and to modulate a beam of radiation in response thereto. The system further includes an electro-optic module configured to receive and convert the beam of radiation from the fiber optic current sensor to an electrical signal.

Abstract: A magnetometer is constructed wherein the sweeping is performed at one half the Larmor frequency and has as its center the absorption line. This allows the emitter to tune onto the absorption line twice per cycle as it passes through the line. This causes the increase in absorption as would the normal sweep of a Bell-Bloom magnetometer but avoids the drawbacks, such as drift and heading error.

Abstract: A condenser lens is incorporated into the end portion of a magnetic field measuring apparatus including a magneto-optical crystal. Alternatively, the end portion of the magnetic field measuring device includes an optical fiber having a core diameter smaller than that of a normal single-mode optical fiber.

Abstract: A continuous observation apparatus of magnetic flux distribution in which a long sample containing a superconducting material or magnetic material is transferred to an observation position and magnetic flux is observed sequentially at each of certain areas along a longitudinal direction of the sample is provided. A method of continuously observing magnetic flux by which a long sample containing a superconducting material or magnetic material is transferred to an observation position and magnetic flux is observed sequentially at each of certain areas along a longitudinal direction of the sample is also provided.

Abstract: A condenser lens is incorporated into the end portion of a magnetic field measuring apparatus including a magneto-optical crystal. Alternatively, the end portion of the magnetic field measuring device includes an optical fiber having a core diameter smaller than that of a normal single-mode optical fiber.

Abstract: An electromagnetic counter includes an electromagnetic counting mechanism in a frame, a plurality of number wheels at least one of which is configured to rotate through a predetermined angle in response to rotation of an electromagnetically motivated anchor, wherein each of the number wheels is disposed proximate a window provided in the front of a frame enclosing cover to form a readable display section. A mounting board supports a light emitting diode for illuminating the display section, and a wiring pattern that supplies electrical power to the light emitting diode. A reflective surface is provided on at least one of an internal surface of the cover member to reflect light from the light emitting diode toward the numbered wheels, the periphery of one or more of the numbered wheels, and indicia formed in the numbered wheels, to render the number wheels readily readable when illuminated by the light emitting diode.

Abstract: A system and method to detect angular rotation, linear displacement and/or surface deformations is presented. The method is based on the ability of a linear polarized light to interact with magnetic materials and to change its polarization angle due to Faraday effect. A basic structure of the system consists of a magneto-optic (MO) film with a two-domain structure and a single domain wall which are generated by gradient magnetic field produced by opposite polarity permanent magnets placed near the film. An AC magnetic field applied perpendicular to the MO film surface causes the magnetic domain wall in the MO film to oscillate at the same frequency. This leads to a detected output AC modulated signal. By measuring the temporal changes in this signal, information on angular rotation, linear displacement and/or surface deformation can be obtained.

Abstract: The device according to the present invention comprises at least one magnetic field generating element, at least one magneto-resistor and at least one resistance-to-current converter generating a current signal dependent on the resistance value of said at least one magneto-resistor. According to the preferred embodiment of the invention four magneto-resistors are used. A plurality of signals dependent on the ratios of the resistance values of said magneto-resistors are generated, the signals being in different phases. The mutual equality of a predetermined pair of the signals and/or the linear combinations thereof is realized only at predetermined relative positions. The relative position of the movable object is determined by counting the number of such predetermined relative positions passed during the movement of the movable object.

Abstract: A method and apparatus for measuring a circularly polarized rotating electromagnetic wave using a magnetic field are provided. The method and apparatus are used to measure properties of a circularly polarized rotating electromagnetic wave occurring in nature by using a phenomenon that energy is intensified or attenuated when circularly polarized rotating electromagnetic waves interact. The method and apparatus are used to measure properties of a circularly polarized rotating electromagnetic wave which causes variations in a magnetic field, when circularly polarized rotating electromagnetic waves are radiated into a magnetic field formed by a magnetic body or the flow of electric current, and the variations in the magnetic field are measured as variations in electric current.

Abstract: In an embodiment, the claimed invention is a device to for optical presentation of magnetic flux. A ferromagnetic colloidal mixture is substantially evenly dispersed and sealed between two optically transmissive lenses. At least one magnetic source is juxtaposed about the viewer. A light source is positioned to project through the mixture, the light interacting with the mixture to create the presentation of magnetic flux. The viewer is optionally positioned within a housing. In another embodiment, the invention is a method of using the viewer to view a presentation of magnetic flux when light interacts with the mixture.

Abstract: A method of enhancing the conversion of magnetic field intensity and spatial data to optical data utilizes surface plasmon resonance combined with corrugated optical gratings of several types. Appropriate materials and methods for producing and applying said corrugations and surface plasmon resonance-producing enhancements to Magneto-Optical Indicator Films (MOIF) are described. Methods of acquiring and interpreting magneto-optical data are also described.

Abstract: A micro-position sensor and sensing system using the Faraday Effect. The sensor uses a permanent magnet to provide a magnetic field, and a magneto-optic material positioned in the magnetic field for rotating the plane of polarization of polarized light transmitted through the magneto-optic material. The magnet is independently movable relative to the magneto-optic material so as to rotate the plane of polarization of the polarized light as a function of the relative position of the magnet. In this manner, the position of the magnet relative to the magneto-optic material may be determined from the rotated polarized light. The sensing system also includes a light source, such as a laser or LED, for producing polarized light, and an optical fiber which is connected to the light source and to the magneto-optic material at a sensing end of the optical fiber.

Abstract: A metrology instrument includes an eddy current sensor that is mounted to and concentric with a confocal distance sensor. By measuring the precise vertical placement of the eddy current probe with respect to the surface of the sample using the confocal distance sensor, the accuracy and precision of the eddy current measurement is improved. Because the confocal distance sensor and the eddy current sensor are confocal, there is no need to move the relative lateral positions between the sample and instrument, between the distance measurement and the eddy current measurement, thereby reducing error in the measurement as well are maximizing the throughput by minimizing the required stage travel for a single measurement.

Abstract: A method and apparatus for determining volume and anisotropy field distribution of thin film granular material includes the use of a magneto-optic probe, a lock-in amplifier, and a computer. The magneto-optic probe utilizes the Kerr effect in order to determine the transverse AC susceptibility of the sample. The Lock-in amplifier determines the complex parameters of the susceptibility as a function of the DC field and AC frequency. Separate distribution values of anisotropy field and grain volume can then be determined mathematically from the relationship of complex susceptibility parameters to the DC field strength.

Abstract: The present invention provides a magnetic sensor capable of reproducing a magnetic record even if the size of a recorded magnetization is a minute one, directly reading a magnetization recorded on a magneto-optical disk without applying incident light itself to the magneto-optical disk, and obtaining signals of a second harmonic having a high S/N ratio. This magnetic sensor includes a magnetic sensor element (102) having electric polarization disposed with respect to a perpendicular recording medium (101), and laser generating means acting on the magnetic sensor element (102). The magnetic sensor reads information in the perpendicular recording medium (101) based on the variation of the rotation angle ? of the polarization plane of a second harmonic (105) of a frequency 2? exiting the magnetic sensor element (102) by the application of laser light (104) with a frequency ? from the laser generation means to the magnetic sensor element (102).

Abstract: An optical current sensor having a reflection interferometer (1, 10) has, in its fiber-optic lead (2), a polarization-maintaining first fiber branch (20) for two forward-traveling orthogonally polarized waves and a polarization-maintaining second fiber branch (20?) for two backward-traveling orthogonally polarized waves. In this case, the two fiber branches (20, 20?) are connected to one another via a coupler (8) on the sensor side. The first fiber branch (20) is connected to a light source (4) and the second fiber branch (20?) is connected to the detector (5). A means for phase shifting (7) is funcionally connected to at least one of the fiber branches (20, 20?). It is thus possible to achieve a quasi-static control of the phase shift of the waves, so that less stringent requirements can be made of the means for phase shifting than of the phase modulators that are usually used in current sensors of this type.

Abstract: A photo magnetic field sensor includes a Faraday rotator made of a paramagnetic material, a polarizer, an analyzer, a light-irradiating element, and a light-sensing element. The Faraday rotator is made of a paramagnetic garnet single crystal including at least Tb and Al.

Abstract: An optical sensor unit, free from electrical noise, includes a sensor case which has both lateral sides having high frequency connectors mounted thereon, and a metallic plate mounted inside the case. The metallic plate has both ends connected to inner conductors of the high frequency connectors, and its upper surface having a current and a voltage sensor unit mounted thereon for measuring the high frequency current and voltage, respectively. The current sensor unit includes total-reflection mirrors and a current sensor, and the voltage sensor unit includes further total-reflection mirrors and a voltage sensor. The voltage sensor has its upper surface having an electrode provided thereon to be connected to the sensor case. The laser light from outside is input to the current and voltage sensor units over optical fibers. The signal light output from the current and voltage sensor units is taken outside on output optical fibers.

Abstract: A sensor enables simultaneous or sequential eddy current and optical reflectance measurements of conducting film by providing an eddy current inspection coil and a first and a second optical fiber extending axially through the coil. The eddy current inspection coil is excited by a radio frequency generator and induces eddy currents in the conducting film which are sensed using a detector. The conducting film is illuminated by a first optical fiber, and light which is reflected from the conducting film is transmitted by a second optical fiber to a detector. The combined use of electrical and optical reflectance signals provides a single probe unit that measures both dielectric and conducting transparent and semi-transparent films.