Abstract: An optical signal is introduced into a polarization rotator to control the optical signal so that the output of the optical signal is maximized through the rotation of a plane of polarization of the optical signal, and then, introduced into the polarizer to pass a linear polarization of the optical signal therethrough, and then, introduced into the optical electric power detector to detect the output of the optical signal.

Abstract: A device and method for optical isolation for use in optical systems is disclosed. The device provides for a waveguide optical isolator fabricated using two arms, made of optical waveguides comprising magneto-optical material, in a Mach-Zehnder interferometer configuration. The device of the present invention operates using the TM mode of a light wave and, thus, does not require phase-matching of TM and TE modes. Further, the present invention does not use polarizers to extinguish the optical feed-back.

Abstract: Magnetic field and/or electrical current imaging systems utilizing magneto-optical indicator films (MOIF) based on magneto-optical material with in-plane single easy axis type of magnetic anisotropy provide improved magnetic field resolution and dynamic range with the use of specific illumination conditions. Methods that provide the two-dimensional distribution of the external magnetic field vectors are disclosed together with the methods of extraction of said information. The visualizing systems offer high spatial resolution and/or high magnetic field resolution combined with fast sampling rates and the capability of performing large-area imaging. The applications of such systems include nondestructive testing and damage assessment in metal structures via magnetic materials or induced currents, integrated circuit testing and quality control, general magnetic material and thin film research, permanent magnet quality control, superconductor research and many others.

Abstract: A device functions as a polarization beam combiner and an isolator. When light is transmitted in a first propagation direction, a second beam is displaced towards a first beam. The second beam has a polarization orthogonal to the polarization of the first beam, and the second beam is substantially parallel to the first beam. The polarizations of the first and second beams are rotated by a same first amount in a first rotation direction and then rotated by the same first amount in a second opposite rotation direction. The first and second beams are combined by displacing the second beam towards the first beam. The combined beam is polarized along a first plane and second plane, which is orthogonal to the first plane. When light is transmitted in a second opposite propagation direction, the device is used to provide optical isolation.

Abstract: An optical isolator comprising a combination of an optical isolator main body and a holder holding the optical isolator main body, the optical isolator main body including a Faraday rotator element, a polarizer and an analyzer disposed at the front and back of the Faraday rotator element, and permanent magnets disposed on the outside of the Faraday rotator element, the polarizer and the analyzer.

Abstract: There are provided a small optical deflector that can be driven at a high speed with a low voltage, provides a large angle of deflection, has a low distortion even in high speed operation and has a high static flatness of a reflective surface, and a method of producing the optical deflector. The optical deflector drives a movable plate relative to a supporting substrate to deflect a light incident on a reflective surface and has a configuration in which at least two recesses are formed in a surface of the movable plate on which the reflective surface is not formed, and a magnetic material is provided in the recesses.

Abstract: Optical devices including a Faraday rotation devices improved in wavelength and temperature characteristics and an optical attenuator reduced in wavelength dependence and temperature-dependent loss. The Faraday rotation device has permanent magnets magnetized in an axial direction of through-holes, and Faraday elements having a same Faraday rotation direction with respect to a same magnetization direction. The permanent magnets are directed in the same magnetization direction along an optical path, where part of the Faraday elements are accommodated in the through-hole of the permanent magnet, and the remaining Faraday elements are arranged between the magnets, whereby the Faraday elements are to be applied by magnetic fields in opposite directions. For a device variable in Faraday rotation angle, an electromagnet is provided. An input fiber collimator and polarizer are provided on an input side of with the Faraday elements while an analyzer and output fiber collimator are on an output side.

Abstract: A spatial light modulator includes: a magnetic layer that is made of a magneto-optic material and includes a plurality of pixels in each of which a magnetization direction is independently set and each of which has a function of causing a rotation of a polarization direction of incident light depending on the magnetization direction by a magneto-optic effect; a plurality of first conductor layers and a plurality of second conductor layers arranged to intersect with each other at positions corresponding to the individual pixels, through which currents for generating magnetic fields to set the magnetization directions in the individual pixels are passed; and a plurality of dielectric layers for enhancing the function of the pixels. A polarization direction of light incident on the spatial light modulator is rotated depending on the magnetization direction of each pixel.

Abstract: A Faraday rotator which is improved in temperature-dependent Faraday rotation angle characteristic and thus in quality. Faraday rotation is caused by a first magnetic field applied to a magneto-optical crystal of the Faraday rotator, and the Faraday rotation angle is controlled by a second magnetic field over an entire variable strength range of the second magnetic field. The magneto-optical crystal is positioned in such a manner that the direction of a combined magnetic field of the first and second magnetic fields, except for the direction of the first magnetic field, is variable intermediately between easy and hard magnetization axes of the magneto-optical crystal.

Abstract: The present invention aims at providing a transmission wavelength characteristics variable optical element which can actively equalize changes of the wavelength characteristics due to temperature changes, and providing a wavelength characteristics variable apparatus, an optical amplifier, an optical transmission system, and a control method of the transmission wavelength characteristics, which use such an optical element.

Abstract: Disclosed is an optical module of an isolator structure including a semiconductor laser, a polarizer, and a Faraday rotator. The laser outputs a first linearly-polarized beam of a predetermined polarization mode. The polarizer is positioned to face an end of the laser, and its polarization axis is tilted at a 45° angle with respect to the polarization direction of the first beam. The Faraday rotator is disposed between the laser and the polarizer, and rotate the polarization direction of the first beam by 45° to substantially coincide with the polarization axis of the polarizer, and then output it to the polarizer, and to rotate a second beam from the polarizer by 45°, wherein the second beam has a polarization mode polarized perpendicular to the first beam, and then output it to the semiconductor laser.

Abstract: The invention relates to an optical device for polarizing light by changing its Faraday rotation angle, such as optical attenuators, optical switches or polarization controllers; and its object is to provide such an optical device which can be driven even by small-sized and power-saving magnetic circuits and in which the insertion loss in the Faraday rotator may be reduced. The optical device comprises a Faraday rotator formed of a garnet single crystal, and a magnetic circuit applying an external magnetic field H that is smaller than the saturation magnetic field Hs of the Faraday rotator to the Faraday rotator.

Abstract: To provide a magneto-optic optical device, such as a variable optical attenuator, an optical modulator or an optical switch, that is small, has a low power consumption and has high speed. The above object is achieved by a magneto-optic optical device characterized by comprising at least one magneto-optical crystal, a magnetic field application mechanism for applying to the magneto-optical crystal a magnetic field component in a direction vertical to a light entrance/exit plane, and at least one electromagnet for changing a position where the magnetic field component applied to the magneto-optical crystal becomes zero.

Abstract: An actuator apparatus, comprising a rotating shaft supported in a freely rotating condition, a rotor magnet consisting of a permanent magnet which is polarized at two poles and is fastened to the rotating shaft; means for defining a first rotational position when the rotating shaft rotates in one direction; means for defining a second rotational position when the rotating shaft rotates in the other direction; and driving means for driving the rotating shaft and rotor magnet, wherein a self-hold state is formed by yokes arranged so as to form a closed magnetic circuit between the one pole and the other pole of the above-mentioned rotor magnet in at least one of the above-mentioned first rotational position and the second rotational position.

Abstract: An optical isolator is disclosed for transmitting light in a first direction and blocking light in a second direction along an optical pathway. The optical isolator includes an input polarizer having a pass axis at first angle, an output polarizer having a pass axis at second angle, a Faraday rotator material between the polarizers having a Verdet constant and an axis of maximum length therethrough, generation means for generating a magnetic field around and inside the rotator material, and at least one reflector configured to define an optical length through the rotator material which is longer than the axis therethrough. The optical pathway length through the rotator material, the magnetic field strength, and the Verdet constant are selected so as to rotate light through the Faraday rotator material from the first angle to the second angle.

Abstract: An optical device includes a Faraday rotator made of a bismuth substituted rare earth iron garnet single crystal (BIG) having a Faraday rotation of 45 degrees, and permanent magnets arranged beside the Faraday rotator to define two or more areas of a single domain structure in the Faraday rotator. Adjacent areas are magnetized in opposite directions to cause the polarization planes of light beams passing through the adjacent areas to rotate in opposite directions. The optical device satisfies the relation expressed by Hs/Br/DH>&Dgr;D/2>0 where Hs (Oe) is a saturation magnetic field of the BIG, DH (cm−1) is a rate of change in magnetic field in the proximity to a boundary between the adjacent areas, Br (Gauss) is a residual flux density of the permanent magnets, and &Dgr;D is a distance between the two light beams.

Abstract: Magnetic field and/or electrical current imaging systems utilizing magneto-optical indicator films (MOIF) based on magneto-optical material with in-plane single easy axis type of magnetic anisotropy provide improved magnetic field resolution and dynamic range with the use of specific illumination conditions. Methods that provide the two-dimensional distribution of the external magnetic field vectors are disclosed together with the methods of extraction of said information. The visualizing systems offer high spatial resolution and/or high magnetic field resolution combined with fast sampling rates and the capability of performing large-area imaging. The applications of such systems include nondestructive testing and damage assessment in metal structures via magnetic materials or induced currents, integrated circuit testing and quality control, general magnetic material and thin film research, permanent magnet quality control, superconductor research and many others.

Abstract: A short intense pulse of radiation is generated by shining radiation through a magneto-optical material and providing multiple stimulations to the material. The material is excited multiple times to rapidly change a property of the radiation, such as the angle of its polarization. The first excitation rotates the polarization in a first direction and the second excitation can rotate the polarization further. Alternatively the second excitation can bring the polarization back to its initial direction. Effect of lengthy relaxation times in the material cancel each other out and the pulse of light has a length that depends on the time difference between the two excitations and the spacing between them. This allows a pulse of light to be produced that has more rotation or has a shorter pulse width than the time for excitation plus the time for normal relaxation of the magneto-optical material.

Abstract: An optical signal is introduced into a polarization rotator to control the optical signal so that the output of the optical signal is maximized through the rotation of a plane of polarization of the optical signal, and then, introduced into the polarizer to pass a linear polarization of the optical signal therethrough, and then, introduced into the optical electric power detector to detect the output of the optical signal.

Abstract: An optical control modulator comprises an input to receive light from a light source, a polarisation divider to divide the light into two orthogonal plane-polarised light components and a Faraday material which upon being energised rotates the plane of polarisation of the plane-polarised light as it passes through the material and an output. The light travels through the Faraday material in opposite directions on a common path. In one embodiment, the light passes once through the Faraday material on a loop path. In another embodiment, the light passes twice through the Faraday material by being reflected by a mirror disposed at a back face of the Faraday material.

Abstract: A spatial light modulator includes a device portion and a bias field applying coil disposed around the device portion. The device portion includes a magnetic layer and two types of conductor layers. The magnetic layer is made of a magneto-optic material and includes a plurality of pixels whose directions of magnetization are set independently of one another. Each of the pixels causes rotation of a direction of polarization of incident light depending on its direction of magnetization due to a magneto-optic effect. The conductor layers generate a magnetic field for setting the direction of magnetization of each of the pixels of the magnetic layer. The magnetic layer has grooves for defining the borders of the individual pixels. The grooves are formed to extend from the top surface of the magnetic layer to a predetermined position between the top and bottom surfaces of the magnetic layer.

Abstract: Miniature optical devices, including circulator array devices, are fabricated using thin film coating technology. A typical optical device according to the present invention includes a spatial walkoff plate (SWP) coupled on opposite ends to first and second polarization orientation elements. First and second polarization beam splitter (PBS) elements are coupled to the first and second polarization orientation elements, respectively. The PBS elements are formed using thin film coating techniques and each includes an array of port coupling regions for coupling to an array of input/output fiber port assemblies. The SWP may be formed using thin film coating techniques or cut from a birefringent single crystal. Each polarization orientation element includes a Faraday rotator element, and in some embodiments, each also includes a wave plate formed using thin film coating techniques.

Abstract: A Faraday rotator of multilayer film type is provided in which satisfactory optical characteristics are obtained with a small number of layers. In the Faraday rotator, a first periodic dielectric multilayer film made of silicon dioxide SiO2 and tantalum pentaoxide Ta2O5 is formed on a substrate, then a magneto-optical thin film, and a second periodic dielectric multilayer film made of tantalum pentaoxide Ta2O5 and silicon dioxide SiO2 are formed sequentially. The first and second periodic dielectric multilayer films sandwich the magneto-optical thin film such that their respective higher refractive dielectric thin films are in contact with the magneto-optical thin film. The number of layers of the first periodic dielectric multilayer film is larger than that of the second periodic dielectric multilayer film.

Abstract: A hard magnetic Bi-substituted rare earth iron garnet material with excellent Faraday rotary moment, temperature property, wavelength property and insertion loss is provided. A Bi-substituted rare earth iron garnet material having a chemical composition of (Bi3−a−b−cGdaTbbYbc) Fe(5−w)MwO12 (where, M is at least one element selected from the group consisting of Ga, Al, Ge, Sc, In, Si and Ti, 0.5≦a+b+c≦2.5, 0.2≦w≦2.5) can be provided with hard magnetism and have excellent Faraday rotary moment, temperature property, wavelength property and insertion loss.

Abstract: Faraday rotator garnet thick films have improved specific Faraday rotations without requiring a bias magnet. Films of nominal composition BiX(EuZHo1-Z)3-XFe5-YGaYO12 are grown lattice matched to available {Gd2.68Ca0.32}[Ga1.04Mg0.32Zr0.64](Ga3)O12 substrates. The film is prepared with Z ≦0.45, which allows higher concentrations of Bi to be included in the film than prior compositions. The increased amount of Bi results in a higher specific Faraday rotations for the film. For devices such as non-reciprocal optoelectronic devices that require 45-degree rotators, the increased specific Faraday rotation results in the use of thinner films of reduced path length as well as increased crystal growth yields.

Abstract: This invention pertains to an improvement on radio transceiver technology. It presents a new method for transmitting and receiving a radio signal. The claims listed within are all limited to the application of the technology for the transmitting and receiving of data. The technology exists as a replacement to the standard antenna. There are subtle variations from existing technologies as well as possible unique applications of the technology being patented. None of the claims are known to be in the public domain, but the distinctions may require legal expertise.

Abstract: The present invention provides improved optical switches in which no mechanical movement is required to direct optical pathways between plural fiber ports. Advantageously, the inventive switches incorporate two-stage polarization rotation to improve isolation depth, as well as temperature and wavelength independence. The inventive switches also incorporate light bending devices to allow two fibers to be coupled to the light beams using a single lens achieving small beam separation for compactness. In the inventive switch, an optical signal is spatially split into two polarized beams by a birefringent element, which passes through a polarization rotation device that comprises waveplates, walk-off elements, and electrically controllable polarization rotators, and recombine into an output fiber, achieving polarization independent operation.

Abstract: A MEMs structure can include a recess in a substrate, the recess having a side wall and a floor. A tail portion of a moveable reflector is on the substrate and extends beyond the side wall of the recess opposite the recess floor and is configured to rotate into the recess. A head portion of the moveable reflector extends on the substrate outside the recess.

Abstract: A small-sized magnetic field generator which is suitable for mass production and provides better output stability. A plurality of coils are formed on a non-magnetic insulating material by depositing at least one layer of conductive film in a spiral pattern. A hollow is made in the center of each coil, so that a plurality of main magnetic cores are arranged on the insulating substrate, with their ends fit into those hollows. By supplying appropriate electrical signals to drive the coils individually, their combined magnetic field can be controlled to have an arbitrary distribution. This combined magnetic field is applied to a magneto-optical target device held on the insulating material.

Abstract: An optical system includes a layer of magneto rheological (MR) fluid having a surface exposed to air or vacuum. The MR fluid has a first state wherein the surface is reflective, and a second state wherein the surface is non-reflective. A magnetic actuator selectively applies a magnetic field to the MR fluid to actuate the fluid to the second state.

Abstract: The invention includes an apparatus for processing an input optical beam. The apparatus has at least one variable optical element to dynamically alter the polarization state of an optical beam to form a polarization-altered optical beam, wherein the polarization-altered optical beam includes elliptical polarization. At least one wave plate operates on the polarization-altered optical beam, each wave plate has a selected retardation, order of retardation, and orientation. A polarization analyzer, operating in conjunction with the at least one variable optical element and wave plate, alters the transmitted amplitude of the polarization-altered optical beam as a function of wavelength, and thereby produces an output optical beam with transmitted amplitude adjusted as a function of wavelength.

Abstract: A magnetic symbology reader has a housing containing a polarized light source which directs light through a magneto-optic sensor onto a reflector which reflects light back through the magneto-optic sensor and then through at least one analyzer and into at least one camera. A view finder allows the user to monitor the image on the magneto-optic sensor as seen by a viewfinder camera while a processor is coupled to possibly a second camera so that when an image is detected, the image from the camera may be processed by the processor to output information associated with the symbol to an external source. The analyzer and polarized light source provide contrast in the images detected by the sensor. A bias/erase coil located about the magneto-optic sensor can enhance or erase images on the sensor.

Abstract: A Faraday rotator which is improved in temperature-dependent Faraday rotation angle characteristic and thus in quality. Faraday rotation is caused by a first magnetic field applied to a magneto-optical crystal of the Faraday rotator, and the Faraday rotation angle is controlled by a second magnetic field over an entire variable strength range of the second magnetic field. The magneto-optical crystal is positioned in such a manner that the direction of a combined magnetic field of the first and second magnetic fields, except for the direction of the first magnetic field, is variable intermediately between easy and hard magnetization axes of the magneto-optical crystal.

Abstract: An integrated micro-optical system includes at least two wafers with at least two optical elements provided on respective surfaces of the at least two wafers. An active element having a characteristic which changes in response to an applied field may be integrated on a bottom surface of the wafers. The resulting optical system may present a high numerical aperture. Preferably, one of the optical elements is a refractive element formed in a material having a high index of refraction.

Abstract: A magneto-optic modulator and method are provided. An optical waveguide having a magneto-optic active medium is magnetized by a biasing magnetic field. The magnetization of the magneto-optic active medium is modulated thereby causing a variation in the Faraday effect on optical signals passing through the magneto-optic medium. The result is a polarization modulated optical signal.

Abstract: An optical system includes a layer of magneto rheological (MR) fluid having a surface exposed to air or vacuum. The MR fluid has a first state wherein the surface is reflective, and a second state wherein the surface is non-reflective. A magnetic actuator selectively applies a magnetic field to the MR fluid to actuate the fluid to the second state.

Abstract: A variable optical attenuator (99) comprises a holder (4), a rotatable mechanism (5), a refractor (6), an input port (2) and an output port (3). The input port and the output port are engaged with corresponding upright beams (42, 43) of the holder, which hold the input port and the output port in alignment with each other. The refractor is mounted on the rotatable mechanism by adhering to or soldering on a groove (52) of the rotatable mechanism, wherein the rotatable mechanism mates with a through hole (46) of the holder to make the center of the refractor and the optical axis of input and output collimators (22, 32) of the input and output ports in line.

Abstract: A magneto-optical isolator (20) for an optical circuit. The isolator includes a substrate, and an optical channel (350) disposed next to the substrate. The optical channel and substrate are configured to transmit optical radiation within the optical channel. The isolator further includes a photonic-crystal rotator (24) formed with the substrate and the optical channel. The rotator has at least one defect (52) and magnetic (M) and non-magnetic (N) materials.

Abstract: A liquid phase epitaxy method is used to grow the Faraday rotator with a small saturation field (Hs). The Faraday rotator has the formula: Bi3−x−y−zGdxTbyMzFe5−w−nGawPnO12, where M is selected from Y, Yb, Lu, and P is selected from Al, Si, Ge. X, y, w and n are chosen from the ranges of 0.5≦x≦1.0, 0.5≦y≦1.0, 0.2≦z≦0.5, 1.5≦x+y+z≦2.0, 0.5≦w≦1.0, 0.15≦n≦0.5, 0.8≦w+n≦1.2. Without M and P, a Type-L Faraday rotator with a linear BH curve is provided, which is well suited for variable optical attenuators. With M and P, a Type-R Faraday rotator with a rectangular hysteresis loop is provided, which is well suited for optical switches. Both are also well suited for use in optical isolators and circulators.

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: An optical filter including first and second polarizers, a Faraday rotator and a birefringent element operating together to filter light with a changeable optical transmittance versus wavelength characteristic curve. The curve has specific characteristics.

Abstract: A micro-optical switch including a flexureless magnetic micromirror hinged centrally over a pin, cone or the like. The pin, cone or the like allows the micromirror to rapidly switch or tilt into a plurality of predefined positions as accurately controlled by an microelectromagnetic assembly. A liquid surrounds the pin or cone, connects the bottom of the surface of the mirror with the substrate supporting the pin or cone, and provides a capillary force holding the mirror onto the pin or cone. The liquid low vapor pressure also dissipates heat generated by the fiberoptic beam reflecting off the top surface of the micromirror.

Abstract: Small mechanical devices fabricated from semiconductor substrates called micro-electromechanical systems (MEMS) are used in the telecommunications industry for various purposes, such as switching and attenuation. Typically a small mirror or arm is moved into or out of the optical path of a beam of light to redirect of attenuate the signal. The present invention relates to a drive circuit for a MEMS device that converts a low voltage source into a higher more useful voltage pulse. The present invention also relates to an optically powered MEMS device utilizing the aforementioned drive circuit. Moreover, the drive circuit according to the present invention can be used to generate a single exponentially decaying pulse that can both generate an actuation force and a braking force for the MEMS device.

Abstract: Various optical devices are provided including a Faraday rotation devices improved in wavelength and temperature characteristics and an optical attenuator reduced in wavelength dependence and temperature-dependent loss. The present invention is a Faraday rotation device 22 having permanent magnets 24, 30 magnetized in an axial direction of through-holes and Faraday elements 28, 32 having a same Faraday rotation direction with respect to a same magnetization direction, the permanent magnets being arranged directed in the same magnetization direction along an optical path, part of the Faraday elements being accommodated in the through-hole of the permanent magnet, the remaining Faraday elements being arranged between the plurality of permanent magnets, whereby the Faraday elements are to be applied by magnetic fields in opposite directions. In the case of a device variable in Faraday rotation angle, an electromagnet (variable magnetic field applying means) 36 is provided.

Abstract: An integrated micro-optical system includes at least two wafers with at least two optical elements provided on respective surfaces of the at least two wafers, at least one of the two optical elements being a spherical lens. The resulting optical system presents a high numerical aperture. One of the optical elements may be a refractive element formed in a material having a high index of refraction.

Abstract: A method of manufacturing is used to manufacture a magnet-free Faraday rotator having a square hysteresis loop, the Faraday rotator being formed of a bismuth-substituted rare earth iron garnet single crystal that has a compensation temperature in the range of 10 to 40° C. and is grown on a non-magnetic garnet substrate by a liquid phase epitaxy. The method comprising the steps of placing the bismuth-substituted rare earth iron garnet single crystal film in an environment of a temperature at least 20° C. away from the compensation temperature; and applying an external magnetic field higher than 1000 Oe to the bismuth-substituted rare earth iron garnet single crystal film so that the bismuth-substituted rare earth iron garnet single crystal film is magnetized to have a square hysteresis loop.

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: A beam shutter is provided which comprises a plane-parallel birefringent element for separation arranged to separate input light beams having orthogonal polarization directions on the same optical path; a plane-parallel birefringent element for synthesis arranged to synthesize light beams having orthogonal polarization directions on different optical paths, for output; the birefringent element for separation and the birefringent element for synthesis being disposed in a spaced apart relationship; and polarization rotating means having a variable Faraday rotator, the polarization rotating means interposed between the birefringent element for separation and the birefringent element for synthesis, for magneto-optically controlling the polarization directions; wherein transmission and interruption of output light beams are controlled by switching the polarization directions by means of the variable Faraday rotator.

Abstract: An optical signal processing apparatus includes a YIG monocrystal serving as a magnetic body. A microstrip is provided on one main face of the YIG monocrystal, and microwaves are input to the microstrip. In order to input a laser beam into the YIG monocrystal, a semiconductor laser, a first lens, and a polarizer are disposed on the outside of one side surface of the YIG monocrystal with respect to the widthwise direction thereof. In order to detect a laser signal output from the YIG monocrystal, a analyzer, a second lens, and a photo detector are disposed on the outside of the other side surface of the YIG monocrystal with respect to the widthwise direction thereof.

Abstract: A magneto-optic modulator modulates signals from a superconducting circuit such as a single-flux-quantum (SFQ) logic system onto a carrier wave light beam. The modulator is formed by depositing a magneto-optic material such as EuSe onto a superconducting ground plane such as that of the circuit. A microwave microstrip line is formed on the magneto-optic material and carries a signal from the circuit. The signal induces an H field in the magneto-optic material which causes the magneto-optic material to modulate the light.