Abstract: A device and method for mapping magnetic fields of a sample at a resolution less than the wavelength of light without altering the magnetic field of the sample is disclosed. A device having a tapered end portion with a magneto-optically active particle positioned at the distal end thereof in communication with a fiber optic for transferring incoming linearly polarized light from a source thereof to the particle and for transferring reflected light from the particle is provided. The fiber optic has a reflective material trapping light within the fiber optic and in communication with a light detector for determining the polarization of light reflected from the particle as a function of the strength and direction of the magnetic field of the sample.

Abstract: The invention relates to apparatus for examining magnetic properties of objects, in particular sheet material, such as bank notes (20). The apparatus comprises a magneto-optic layer (10) whose optical properties are influenceable by the magnetic properties of the sheet material (20), a light source (11) for producing light that is coupled into the magneto-optic layer (10), and a detector (13) for detecting light that is transmitted and/or reflected by the magneto-optic layer (10). For reliable examination of the magnetic properties of sheet material it is provided that the direction of propagation of the coupled-in light extends parallel to a base surface (9) of the magneto-optic layer (10). The invention permits the magnetic properties in particular of sheet material with areas emitting very weak magnetic fields to be examined with very high sensitivity and reliability.

Abstract: An electromagnetic counter includes a case, an electromagnet, an anchor rotatable through magnetization and demagnetization of the electromagnet, and number wheels rotated by a predetermined angle according to the rotation of the anchor. A flexible board with a light emitting diode is disposed in a confined space in the case for illuminating the number wheels.

Abstract: An optical microcantilever has an optical waveguide for propagating light. The optical waveguide has a first side, a second side opposite to the first side, and a tip portion formed on the first side and at a free end of the optical waveguide. The tip portion has a microscopic aperture. A light blocking film is disposed on the first side of the optical waveguide. A reflecting film is disposed on the second side of the optical waveguide. A reflecting member forms part of the reflecting film and is disposed at the free end of the optical waveguide. The reflecting member has a generally planar surface for reflecting light propagated by the optical waveguide and for guiding the reflected light towards the microscopic aperture to generate near-field light at the microscopic aperture.

Abstract: A Lorentz Force magnetometer based on a mechanical resonator including a resonant, vibrating electrically conducting string or insulating fiber coated with an electrically conducting material and its response to a Lorentz Force wherein the string or fiber, fixed at two ends, is tensioned over two frets (supports) separated by a distance, L, hence, becoming mechanically resonant with high Q. The frets constrain the position of the string or fiber but not the angle it makes with the fret, thus, permitting measurement of multiple vector magnetic fields. The magnetometer can be easily manufactured in arrays with the tension and, hence, resonant frequency for each magnetometer being rapidly, sequentially, and dynamically varied through the use of, e.g., piezo/MEMS elements. If the fiber is light conducting, a compact and sensitive detector using light escaping from an aperature in the conducting material coating the fiber can be implemented.

Abstract: The invention relates to apparatuses and a corresponding method for examining magnetic properties of objects, in particular sheet material, such as bank notes (20). The apparatuses comprise a magneto-optic layer (10) whose optical properties are influenceable by the magnetic properties of the sheet material (20), a light source (11) for producing light that is coupled into the magneto-optic layer (10), and a detector (13) for detecting light that is transmitted and/or reflected by the magneto-optic layer (10). For reliable examination of the magnetic properties of sheet material it is provided that the direction of propagation of the coupled-in light extends parallel to a base surface (9) of the magneto-optic layer (10). The invention permits the magnetic properties in particular of sheet material with areas emitting very weak magnetic fields to be examined with very high sensitivity and reliability.

Abstract: There is disclosed a method and apparatus for spectroscopically sensing a man-made, terrestrial or atmospheric magnetic field emanating from an object that includes receiving a radiance emission from an object and dispersing the radiance emission into parts of the electromagnetic spectrum. The method also includes detecting a part of the electromagnetic spectrum identified with a selected gas and measuring the magnetic field from a part of the electromagnetic spectrum based on spectral spreading of a spectral line.

Abstract: Described are improved transmissive magneto-optical sensors that may be used to determine the magnitude and phase of a magnetic field surrounding a conductor, and when in contact with the conductor, the surface temperature of the conductor. The magneto-optical sensor may be made to be symmetric around the direction of propagation of the internal light, enabling ease of manufacturing as well as automated assembly and calibration. The magneto-optical sensor may also be made to be symmetric about the plane determined by the Faraday rotator material, thus enabling reciprocating optical paths for increased vibration and birefringence immunity. The disclosed sensors preferably include cylindrically symmetrical components, thereby making the sensor readily mass-producible.

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: An apparatus which attenuates a light signal polarized in a first direction. The apparatus includes a polarization rotation unit and an output unit. The polarization rotation unit rotates the polarization of the light signal to produce a polarization rotated light signal having a polarization component in the first direction and a polarization component in a second direction which is substantially 90 degrees with respect to the first direction. The output unit passes, as an output signal, the polarization component in the second direction of the polarization rotated light signal and blocks the polarization component in the first direction. The polarization rotation unit includes an electromagnet and a permanent magnet which apply magnetic fields in specific directions with respect to the light path. Various yoke constructions are provided for the electromagnet and the permanent magnet.

Abstract: A device 10 for sensing a magnetic field gradient using an optically powered resonant integrated microstructure (O-RIMS). The O-RIMS comprises a microbeam 11 having a resonant frequency, a shell 16 supporting the microbeam 11, sensor electronics, a light transporter 36, such as an optical fiber or optical waveguide, in proximity to the shell 16, and a ferromagnetic or magnetically permeable element 26 attached to the shell 16. The ferromagnetic or magnetically permeable element 26 experiences a torque about the fulcrum 24 when a magnetic field gradient is present, and causes a strain on the shell 16. The strain is in turn transmitted to the microbeam 11, thereby affecting its resonant frequency. The change in resonant frequency of the microbeam 11 is conveyed to the sensor electronics via the light transporter 36.

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: The invention relates to apparatuses and a corresponding method for examining magnetic properties of objects, in particular sheet material, such as bank notes (20). The apparatuses comprise a magneto-optic layer (10) whose optical properties are influenceable by the magnetic properties of the sheet material (20), a light source (11) for producing light that is coupled into the magneto-optic layer (10), and a detector (13) for detecting light that is transmitted and/or reflected by the magneto-optic layer (10).

Abstract: A method and apparatus for measuring electromagnetic pulses as a function of time. Radiation measurement, including measurement of single-shot, free-space terahertz femtosecond pulses, is realized using an electro-optical modulator in combination with an optical streak camera. This method and apparatus allow measurement of electromagnetic pulses previously unmeasurable due to the time resolution restrictions dictated by the time-frequency correlation.

Abstract: The invention is a method and apparatus for measuring the strengths of magnetic fields directly in units of frequency of a rotating or oscillating electric field utilising a novel resonance phenomenon called atomic pseudo-spin resonance, ApSR. The ratio of field to frequency is 2m/e, where m and e are the reduced electron mass and the elementary charge, respectively. The magnetic field-strength is thus tied directly to the best physical standard known at present, the frequency of atomic clocks, and the tie is a fundamental constant of nature known with exceedingly good precision.

Abstract: The present invention provides a method for measuring both magnetic and electric fields of a DUT via an electro-optic probing technique at the same time. Also, the present invention provides a method for measuring both electric and magnetic fields via a magneto-optic probing technique simultaneously. The method utilizes the modulation of the position of a probe to measure the electric and magnetic field signals. The DC and AC components of the modulated electric (or magnetic) field signals can be obtained by means of a low pass filter and a lock-in amplifier, respectively. Through a simple calculation, the electric and magnetic field can be obtained simultaneously.

Abstract: A system and method for gathering and analyzing data captured from one or more remote sensing units positioned in the field. Remote sensing units preferably utilize optical sensors. Power to sensing unit components is preferably selectively controlled to reduce power consumption. Remote sensing units according to the invention can be used for a variety of purposes, including water quality or electrical power monitoring, and data from such sensing units is preferably transmitted to a secure host terminal via a communications link. The host terminal preferably formats, analyzes, and stores the data for customer review and retrieval. If alarm conditions exist that require immediate customer notification, such notification can be sent to a customer via one or more telecommunications means. Through the use of the present invention, businesses can shift from a reactive to a proactive mode of monitoring and operation.

Abstract: An optical isolator includes a first magnetic polar source having a first magnet axis, a second magnetic polar source having a second magnet axis parallel to the first magnet axis, and an optical element between the first and second magnetic polar sources, and having a length along the first magnet axis that is less than a length of the first magnetic polar source along the first magnet axis. The optical element has a central axis that is tilted with respect to the second magnet axis.

Abstract: A method and system for sensing magnetic fields using an AC current carrying wire which vibrates or moves in the presence of a magnetic field. The system uses the wire movement to determine one or more characteristics of the field. The wire is connected at a first and second location to the base with an portion between the connection locations having an apex spaced apart from the base. The monitoring system detects movement of the wire at the portion while an electrical current having the same frequency as the mechanical resonant frequency of the wire is sent through the wire and a magnetic field surrounds the portion. The reporting system determines one or more characteristics of the magnetic field based upon the detected movements.

Abstract: An optical current transducer configured to sense current in the conductor is disclosed. The optical current transducer includes a light source and a polarizer that generates linearly polarized light received from a the light source. The light is communicated to a magneto-optic garnet that includes, among other elements, bismuth, iron and oxygen and is coupled to the conductor. The magneto-optic garnet is configured to rotate the polarization of the linearly polarized light received from the polarizer. The optical current transducer also includes an analyzer in optical communication with the magneto-optic garnet. The analyzer detects the rotation of the linearly polarized light caused by the magneto-optic garnet.

Abstract: The present invention provides a method for measuring both magnetic and electric fields of a DUT via an electro-optic probing technique at the same time. Also, the present invention provides a method for measuring both electric and magnetic fields via a magneto-optic probing technique simultaneously. The method utilizes the modulation of the position of a probe to measure the electric and magnetic field signals. The DC and AC components of the modulated electric (or magnetic) field signals can be obtained by means of a low pass filter and a lock-in amplifier, respectively. Through a simple calculation, the electric and magnetic field can be obtained simultaneously.

Abstract: Described are improved transmissive magneto-optical sensors that may be used to determine the magnitude and phase of a magnetic field surrounding a conductor, and when in contact with the conductor, the surface temperature of the conductor. The magneto-optical sensor may be made to be symmetric around the direction of propagation of the internal light, enabling ease of manufacturing as well as automated assembly and calibration. The magneto-optical sensor may also be made to be symmetric about the plane determined by the Faraday rotator material, thus enabling reciprocating optical paths for increased vibration and birefringence immunity. The disclosed sensors preferably include cylindrically symmetrical components, thereby making the sensor readily mass-producible.

Abstract: A device 10 for sensing a magnetic field gradient using an optically powered resonant integrated microstructure (O-RIMS). The O-RIMS comprises a microbeam 11 having a resonant frequency, a shell 16 supporting the microbeam 11, sensor electronics, a light transporter 36, such as an optical fiber or optical waveguide, in proximity to the shell 16, and a ferromagnetic or magnetically permeable element 26 attached to the shell 16. The ferromagnetic or magnetically permeable element 26 experiences a torque about the fulcrum 24 when a magnetic field gradient is present, and causes a strain on the shell 16. The strain is in turn transmitted to the microbeam 11, thereby affecting its resonant frequency. The change in resonant frequency of the microbeam 11 is conveyed to the sensor electronics via the light transporter 36.

Abstract: An optical apparatus and methods for efficiently determining the magnetization of a material at very high optical resolution are disclosed. Individual components of the magnetization may be determined. Components in the plane of the sample surface are imaged by illuminating the material obliquely with substantially parallel light of relatively high power and very well controlled uniformity and polarization, and using light scattered obliquely in a parallel beam in the opposite direction at the same angle as the angle of incidence to record an image. Reversing the illumination and observation directions allows subtraction of the two images and measurement of the magnetization in-plane. A second in-plane component orthogonal to the first, is obtained similarly after reorienting the plane of incidence 90 degrees.

Abstract: In all-optical networks, high speed optical switching and routing becomes one of the most important issues for interconnecting the transport network layers. This invention describes novel polarization-independent high speed optical switches using a digital Faraday rotator, which can also be used for various other optical switching devices. The basic digital Faraday rotator device is composed of (a) a semi-hard or hard iron garnet based magneto-optic crystal having bi-stable magnetization states at zero external magnetic field. (b) a wire winding around the crystal for changing the magnetization states by pulsed current having both fast rise time and short duration. (c) a circuit generating the required current pulses with both polarities.

Abstract: Characterization of free-space electromagnetic energy pulses (15) using a chirped optical probe beam is provided. An electro-optic or magneto-optic crystal (14) is positioned such that the free-space radiation and chirped optical probe signal co-propagate, preferably in a co-linear common direction, through the crystal where a temporal waveform of the free-space radiation is linearly encoded onto a wavelength spectrum of the chirped optical probe signal. The temporal waveform of the free-space radiation is then reconstructed using, for example, a dynamic subtraction of the spectral distribution of the chirped optical probe signal without modulation from the spectral distribution of the chirped optical probe signal with modulation by the free-space radiation.

Abstract: An apparatus which attenuates a light signal polarized in a first direction. The apparatus includes a polarization rotation unit and an output unit. The polarization rotation unit rotates the polarization of the light signal to produce a polarization rotated light signal having a polarization component in the first direction and a polarization component in a second direction which is substantially 90 degrees with respect to the first direction. The output unit passes, as an output signal, the polarization component in the second direction of the polarization rotated light signal and blocks the polarization component in the first direction. The polarization rotation unit includes an electromagnet and a permanent magnet which apply magnetic fields in specific directions with respect to the light path. Various yoke constructions are provided for the electromagnet and the permanent magnet.

Abstract: Described are the design of a rare earth iron garnet sensor element, optical methods of interrogating the sensor element, methods of coupling the optical sensor element to a waveguide, and an optical and electrical processing system for monitoring the polarization rotation of a linearly polarized wavefront undergoing external modulation due to magnetic field or electrical current fluctuation. The sensor element uses the Faraday effect, an intrinsic property of certain rare-earth iron garnet materials, to rotate the polarization state of light in the presence of a magnetic field. The sensor element may be coated with a thin-film mirror to effectively double the optical path length, providing twice the sensitivity for a given field strength or temperature change. A semiconductor sensor system using a rare earth iron garnet sensor element is described.

Abstract: A magneto-optical microscope magnetometer capable of simultaneously measuring a hysteresis loop and activation magnetic moment of a submicrometer-scale local area (about 0.3×0.3 &mgr;m). An electromagnet capable of applying a magnetic field to a magnetic material is attached to a polarizing optical microscope capable of observing a magnetized state of the magnetic material, such that images of the microscope varying with the strength of the applied magnetic field are grabbed in real time by a charge coupled device camera and then analyzed. The magneto-optical microscope magnetometer can measure a hysteresis loop and activation magnetic moment in a submicrometer-scale local area observed by the polarizing optical microscope. Further, the magneto-optical microscope magnetometer can measure hysteresis loops and activation magnetic moments simultaneously with respect to all CCD pixels of the camera and observe coercivity and activation magnetic moment distributions of the entire magnetic material.

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: A system and method for realizing vector Kerr magnetometry are disclosed. The system enables simultaneous longitudinal and transverse Kerr effect measurements at each point on a sample surface. An optional component includes a sample platform for achieving precise linear and rotational relocation. The repositionable platform enables complete, 360 degree characterization about a single point. Additionally, the platform control mechanism may be utilized in obtaining longitudinal and transverse Kerr effect measurements at succeeding points on the surface of a sample. Rapid sample characterization is thus achieved.

Abstract: A proximity detector for detecting the position of a magnetic target having a transceiver module with a light emitting source, an optical detector, and a 2×2 optical coupler joining the light emitting source and optical detector is provided. A sensor having an outer case houses a collimating lens, a polarizer, a Faraday material, and a mirror. A multi-mode optical fiber connects the transceiver module to the sensor. Preferably, the proximity detector detects the position of the magnetic target, which is substantially axially spaced from the sensor, using a single polarizer aligned with a single Faraday material. Preferably, the Faraday material comprises an iron garnet material, and most preferably a bismuth iron garnet material.

Abstract: A magnetic field is measured with the aid of the Faraday effect. Light is coupled into a Faraday element subjected to the magnetic field, the light having a linearly polarized first component at a first wavelength and an unpolarized second component at a second wavelength different from the first. A light signal is coupled out of the Faraday element and is split optically into a first light signal component with the first wavelength and a second light signal component with the second wavelength. A first measurement signal is derived from the first light signal component and a second measurement signal is derived from the second light signal component and these are used to form a corrected measurement signal S. In this way, attenuation influences in the transmission paths can be largely compensated for, even when measuring a magnetic field which is constant over time or a magnetic field with a component which is constant over time.

Abstract: A galvanometer mirror is capable of inclining a reflective mirror around an axis, and has springs. An end of the spring in the vicinity of a movable part is inserted into a second holder, and is then electrically connected to each of terminals. Flexible cables are soldered to these terminals, respectively. Thus, coils are able to receive currents passing through the flexible cables and the terminals, respectively.

Abstract: Light with a plane of polarization rotated during transmission is converted to parallel light by a collimating lens. The parallel light is transmitted through a first birefringent plate to be separated into two polarized rays orthogonal to each other regardless of the rotation of the plane of polarization. The two polarized rays have planes of polarization rotated by the strength of a magnetic field in the course of transmission through a Faraday element. The polarized rays are reflected by a mirror at a downstream stage, each ray returning along the same optical path and transmitted through the birefringent plate again. At this time, the polarized rays are separated into four polarized rays with different ratios of light intensity according to the rotation of the planes of polarization. From these rays, the collimating lens selects only two orthogonal polarized rays to be detected. The selected rays are detected by a photodetector at a downstream stage.

Abstract: A low-rate data transmission system and method are disclosed that use the Faraday effect to modulate the polarization state of light traveling in an optical fiber. The resulting change in polarization is used to communicate information over the fiber. The low-rate data transmission system includes a low-rate signal source producing current in a wire coil wrapped around an optical fiber. Information is conveyed in accordance with the present invention by the selectively introducing a polarization change into the light carried by the fiber. Generally, the source light at the input of the optical fiber can be randomly polarized and information is conveyed in accordance with the present invention by the presence or absence of a predefined polarization introduced into the light. The longitudinal magnetic field produced by a current in the coil rotates the plane of polarization of the light, in accordance with the well-known Faraday effect.

Abstract: Magnetic characterization of the magnetic field emanating from an RWH device is presented using a magnetostrictive layer as a probe between the device and the scanned SFM tip. The findings suggest a very promising technique to resolve magnetic fields laterally at least in the 100 nm realm. Other magnetosensitive properties such as the magnetoelastic and the piezomagnetic effect can be used in a similar way to infer magnetic characteristics of microstructures or of magnetic multilayers.

Abstract: Described are the design of a rare earth iron garnet sensor element, optical methods of interrogating the sensor element, methods of coupling the optical sensor element to a waveguide, and an optical and electrical processing system for monitoring the polarization rotation of a linearly polarized wavefront undergoing external modulation due to magnetic field or electrical current fluctuation. The sensor element uses the Faraday effect, an intrinsic property of certain rare-earth iron garnet materials, to rotate the polarization state of light in the presence of a magnetic field. The sensor element may be coated with a thin-film mirror to effectively double the optical path length, providing twice the sensitivity for a given field strength or temperature change. A semiconductor sensor system using a rare earth iron garnet sensor element is described.

Abstract: A smart magnetometer which includes at least one cantilevered magnetostrictive/optical fiber structural bonded composite in a vibrationally isolated housing allowing an optical signal to be transmitted and detected from one optical fiber to another such that fluctuations of the surrounding magnetic field H will cause fluctuating mechanical torque on the composite magnetostrictive beam which will be applied to the bonded cantilevered optical fiber to deflect or misalign and cause modulation of the optical signal transmitted between the two fibers. This modulation can be calibrated to the dynamic variation of strength of a neighboring magnetic field to a precision and sensitivity of less than 1 fT and 1 fT/sqrtHz. The system is smart to selectively filter out any neighboring magnetic field with average strength smaller or greater than a certain critical value.

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: A measurement system is used in particular to detect defects in test objects. To that end, the test object is lighted from a lighting unit that includes a plurality of laser diodes. The beam cones of the individual laser diodes generate a common lighting spot on the test object. The object being measured is observed interferometrically, where the interferometer is part of a measurement head. An electronic pattern sensor detects interference patterns generated by the interferometer.

Abstract: Characterization of free-space electromagnetic energy pulses (15) using a chirped optical probe beam is provided. An electro-optic or magneto-optic crystal (14) is positioned such that the free-space radiation and chirped optical probe signal co-propagate, preferably in a co-linear common direction, through the crystal where a temporal waveform of the free-space radiation is linearly encoded onto a wavelength spectrum of the chirped optical probe signal. The temporal waveform of the free-space radiation is then reconstructed using, for example, a dynamic subtraction of the spectral distribution of the chirped optical probe signal without modulation from the spectral distribution of the chirped optical probe signal with modulation by the free-space radiation.

Abstract: An optical magnetic field sensor probe for detecting a magnetic field to be measured as an output light intensity, by disposing a polarizer, a magneto-optical device, and an analyzer mutually different in the transmission and polarization direction with respect to said polarizer, along the running direction of light, has an input optical fiber for feeding into to said polarizer through a first lens, and an output optical fiber for emitting an output light from said analyzer through a second lens, wherein said input optical fiber, said first lens, said magneto-optical device, said second lens and said output optical fiber are composed in a confocal optical system, and said first lens and said second lens are drum lenses.

Abstract: A magnetic potential mapping device is provided by placing a planar polarized light source near an optically active fiber element traversing a magnetic field, so constructed that rotating planar polarized light is transmitted through the optical fiber and detected by a light detector at the fiber element's other end. The light detector measures an angle of rotation of rotating polarized light. Rotation of polarized light within the optical fiber traversing the field directly indicates magnetic potential at the point where the angle of rotation is measured, with respect to the magnetic potential at the point where the light entered the fiber element. Measuring the rotation of the polarized light passing through each fiber within the field allows mapping the magnetic potentials at any point in the magnetic field with respect to the point at which the light enters the optically active fiber. The present invention also contemplates a related method for automatically compensating a magnetic field source.

Abstract: An optical magnetic field sensor probe for detecting a magnetic field to be measured as an output light intensity, by disposing a polarizer, a magneto-optical device, and an analyzer mutually different in the transmission and polarization direction with respect to said polarizer, along the running direction of light, has an input optical fiber for feeding into to said polarizer through a first lens, and an output optical fiber for emitting an output light from said analyzer through a second lens, wherein said input optical fiber, said first lens, said magneto-optical device, said second lens and said output optical fiber are composed in a confocal optical system, and said first lens and said second lens are drum lenses.

Abstract: The present invention relates to a device for measuring a current in a magnetic field which includes a glass article wherein the glass may be an oxyfluoride glass or a bismuth oxide glass having a photoelastic coefficient of from about −0.2 to 0.2 at 546 nm. Further, the present invention relates to a method of measuring currents.

Abstract: A sensor for facilitating the measurement of temperature and magnetic field is described. The sensor comprises an optical cable having a distal end encompassed in a sheath of giant magnetoresistive material. Temperature changes alter the spectrum emissivity of the giant magnetoresistive material. Magnetic field changes alter the spectrum changes that occur from distorting the optical fiber that occur when the giant magnetoresistive material distorts the optical fiber.

Abstract: The invention uniquely avails of Fourier analytical principles for determining the distribution of a magnetic field in a one-dimensional (linear), two-dimensional (planar) or three-dimensional (spatial) region of interest. According to many embodiments, integrating sensor apparatus having an associated length is inventively implemented so as to measure the magnetic field amplitude value for each of two or more different points. Alternating current is applied at at least one high frequency whereby, for each such frequency, the associated wavelength corresponds to some multiple of the sensor's length. Coiled around the sensor is/are one or more solenoids which is/are configured so as to establish a standing wave along the sensor's length. Inventive adaptation of the sensor's integrating function basically entails regarding a Fourier-type harmonic bias function as being consequential of the standing wave.

Abstract: Light with a plane of polarization rotated during transmission is converted to parallel light by a collimating lens. The parallel light is transmitted through a first birefringent plate to be separated into two polarized rays orthogonal to each other regardless of the rotation of the plane of polarization. The two polarized rays have planes of polarization rotated by the strength of a magnetic field in the course of transmission through a Faraday element. The polarized rays are reflected by a mirror at a downstream stage, each ray returning along the same optical path and transmitted through the birefringent plate again. At this time, the polarized rays are separated into four polarized rays with different ratios of light intensity according to the rotation of the planes of polarization. From these rays, the collimating lens selects only two orthogonal polarized rays to be detected. The selected rays are detected by a photodetector at a downstream stage.

Abstract: A laminated transparent structure for a reflective display which is used, for example, as a head-up display of an automotive vehicle. The laminated transparent structure comprises a glass plate. A transparent layer is bonded to the glass plate. An optical rotation film is disposed between the glass plate and the transparent layer. Additionally, a hot-melt adhesive is disposed between the optical rotation film and the glass plate to bond the optical rotation film to the glass plate.