Nec Corporation

Tdk Corporation

National Institute of Advanced Industrial Science and Technology

Kabushiki Kaisha Toshiba

Masafumi Nakada

Kazuhiko Hayashi

Keishi Ohashi

Nobuyuki Ishiwata

Kunihiko Ishihara

Junichi Fujikata

Kiyokazu Nagahara

Tsutomu Ishi

Shigeru Mori

Atsushi Kamijo

Hisanao Tsuge

Hisao Matsutera

Jun-Ichi Fujikata

Hiroaki Honjou

Eizo Fukami

Yuji Tsukamoto

Hidefumi Yamamoto

Mizuki Iwanami

Takanori Shimizu

Norio Masuda

Hiroaki Honjo

Shinsaku Saitoh

Jun Akedo

Keishi Oohashi

Ishiwata Nobuyuki

Nobuo Suzuki

Masatsugu Ogawa

Tamaki Toba

Daisuke Okamoto

Tsuneo Tsukagoshi

Risato Ohhira

Tomonori Yamada

Kivokazu Nagahara

There is provided an electromagnetic field measurement apparatus capable of achieving correct and timely circuit operation detection in an area where electronic devices are mounted at high density. An electromagnetic field measurement apparatus includes: a laser light source; a polarized wave controller that linearly polarizes laser light; an optical fiber probe that has an electrooptic material or a magnetooptic material at its leading end and in which the laser light reflected at the leading end is subjected to polarization modulation in accordance with an electric field intensity or a magnetic field intensity; and an analyzer that converts the laser light reflected by the optical fiber probe into intensity modulated light. The laser light source emits time-multiplexed laser light of a plurality of wavelengths different from one another. The electromagnetic field measurement apparatus further includes: an optical circulator that outputs the laser light linearly polarized by the polarized wave controller to a multiplexer/demultiplexer and outputs the laser light input from the multiplexer/demultiplexer to the analyzer; and a multiplexer/demultiplexer that outputs the laser light to different optical fiber probes according to the wavelength of the laser light and outputs the laser light to the optical circulator.

Electromagnetic field measurement apparatus

A magnetic field sensor fabrication method of directly forming, with an aerosol deposition method, at a tip of an optical fiber, a magnetooptical layer having a refractive index that changes depending on a magnetic field, the method includes establishing a relationship of dc&#x2266;d&#x2266;dr among a diameter d of the magnetooptical layer, a diameter dc of a core of the optical fiber, and a diameter dr of a clad thereof.

Electric field/magnetic field sensors and methods of fabricating the same

Provided is an optical device that includes a ring-shaped optical waveguide and an input/output optical waveguide, and that changes a resonant wavelength of the ring-shaped optical waveguide, in which the ring-shaped optical waveguide includes in part a refractive index control section for controlling a refractive index at a guided wavelength, and the refractive index control section is formed of an optical material having a thermo-optic effect with its sign different from that of an optical material that forms a section of the ring-shaped optical waveguide other than the refractive index control section.

Optical device, method for manufacturing the same and optical integrated device using the same

There is provided a waveguide type optical device whose parasitic capacitance is reduced to allow an increase in signal transmission speed. Bottom electrodeis formed on substrate, bottom claddingis formed on bottom electrode, and bottom coreis formed on bottom cladding. Top coreis formed on bottom core, top claddingis formed on top core, and top electrodeis formed on top cladding. Two sides of top coreand bottom coreare covered with side cladding layer. Vertically overlapping portions of top electrodeand bottom electrodeare located almost at a same place as a region for a core layer composed of top coreand bottom core. The width of one from among top coreand bottom coreis satisfying a single mode condition, and the width of the other is almost equal to or more than the width of a field distribution.

Waveguide type optical device

At least part of an optical device comprises an optical waveguide of a magneto-optical material. The magneto-optical material comprises a polycrystalline material having no lattice matching with an underlayer material. The optical waveguide exhibits no magnetic anisotropy due to an inverse magnetostriction effect caused by thermal strain. The magnetization direction of the optical waveguide is aligned with a traveling direction of light passing through the waveguide by shape magnetic anisotropy.

Optical device, optical integrated device, and method of manufacturing the same

An electric field sensor or a magnetic field sensor includes an optical fiber and an electro-optic layer or a magneto-optic layer. The electro-optic layer or a magneto-optic layer is provided on an end surface of an end portion of the optical fiber. The end surface of the optical fiber is a convex shape. The optical fiber may have the end portion with a shape of a substantial cone formed by extending the end portion, and the electro-optic layer or the magneto-optic layer may be formed on a side surface of a front end of the substantial cone. A dielectric layer may be further included between the optic layer and the end surface.

Electric field sensor, magnetic field sensor, electromagnetic field sensor and electromagnetic field measuring system using these sensors

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.

Electric field sensor and method for fabricating the same

Provided is a small-size optical phase modulation element and an optical modulator using it. The optical phase modulation element includes a Plasmon waveguide having a clad made of a metal material having a complex dielectric constant having a negative real part in the used wavelength and a core formed by a dielectric metal material having a complex dielectric constant having a positive real part in the used wavelength. The Plasmon waveguide is connected to an optical waveguide including a clad and a core both having a complex dielectric constant having a positive real part. The core of the Plasmon waveguide and the core of the optical waveguide are formed, at least partially, of the same semiconductor material. The Plasmon waveguide has a function to phase-modulate the incident light when voltage is applied.

Optical phase modulation element and optical modulator using the same

In a compact formed by subjecting an ultrafine particle brittle material supplied on a substrate to mechanical impact force as a load, whereby the ultrafine particle brittle material is crushed and joined to each other, manganese is added into the ultrafine particle brittle material to form the compact.

Optical element, integrated optic device and optical information transmission system

In a magnetoresistive effect transducer including a pinning layer, a pinned layer, a free layer and a non-magnetic layer inserted between the pinned layer and the free layer, a longitudinal bias layer is connected directly to a part of the free layer to apply a bias magnetic field to the free layer, thus biasing a magnetization direction of the free layer so that the magnetization direction of the free layer coincides with that of the longitudinal bias layer.

Magnetoresistive effect transducer having longitudinal bias layer and control layer directly connected to free layer

A magneto-resistance effect head is provided with a lower conductive layer which is provided with a recessed portion, and a vertical bias layer is provided in the recessed portion. A first magnetic layer is provided on the lower conductive layer. On the first magnetic layer, layered in the following order are the non-magnetic layer, the fixed layer, the fixing layer, and the upper layer so as not to be placed immediately above the vertical bias layer. The non-magnetic layer, the fixed layer, the fixing layer, and the upper layer are buried in an insulation layer. Furthermore, an upper conductive layer is provided on the upper layer and the insulation layer. In the direction of the magnetic field applied by the vertical bias layer, the free layer is made greater in length than the fixed layer and the free layer is disposed in proximity to the vertical bias layer with the distance between the fixed layer and the vertical bias layer remaining unchanged.

Magneto-resistance effect element and magneto-resistance effect head

A magneto-resistance effect head is provided with a lower conductive layer which is provided with a recessed portion, and a vertical bias layer is provided in the recessed portion. A free layer is provided on the lower conductive layer. On the free layer, layered in the following order are the non-magnetic layer, the fixed layer, the fixing layer, and the upper layer so as not to be placed immediately above the vertical bias layer. The non-magnetic layer, the fixed layer, the fixing layer, and the upper layer are buried in an insulation layer. Furthermore, an upper conductive layer is provided on the upper layer and the insulation layer. In the direction of the magnetic field applied by the vertical bias layer, the free layer is made greater in length than the fixed layer and the free layer is disposed in proximity to the vertical bias layer with the distance between the fixed layer and the vertical bias layer remaining unchanged.

Magneto-resistance effect element, magneto-resistance effect head, magneto-resistance transducer system, and magnetic storage system

A magneto-resistance effect head is provided with a lower conductive layer which is provided with a recessed portion, and a vertical bias layer is provided in the recessed portion. A free layer is provided on the lower conductive layer. On the free layer, layered in the following order are the non-magnetic layer, the fixed layer, the fixing layer, and the upper layer so as not to be placed immediately above the vertical bias layer. Furthermore, an upper conductive layer is provided on the upper layer and an insulation layer. In the direction of the magnetic field applied by the vertical bias layer, the free layer is made greater in length than the fixed layer and the free layer is disposed in proximity to the vertical bias layer with the distance between the fixed layer and the vertical bias layer remaining unchanged.

Laser light emitted from a vertically confined surface emitting laser (VCSEL) is incident on a side surface near an end region of an optical waveguide. The end region of the optical waveguide is processed by polishing to taper at an angle of 45 degrees, and an optical modulator is formed on the polished surface. The optical modulator is a Fabry-Perot modulator using a linear electro-optical effect. The modulator has a thick transparent electro-optical layer which is deposited by using an aerosol deposition method.

Optical modulator and method of manufacturing same

A magneto-resistance effect element is adapted that a non-magnetic layer (9, 18), a free layer (3, 19), another non-magnetic layer (4, 25), a fixed layer (5, 26), and a fixing layer (6, 27) are formed vertically symmetric with respect to a first magnetic layer (8), to which a vertical bias magnetic field is applied from an underlying layer (2) for a vertical bias layer (2). The magneto-resistance effect element operates in CPP mode. Generally, the free layer is unavoidably subjected to the influence of a circular electric magnetic field caused by a current flowing perpendicularly to the film surface. However, in the magneto-resistance effect element, the influence of the electric magnetic field to which the free layer (3) is subjected is opposite to that of the electric magnetic field to which the second free layer (19) is subjected, thereby canceling out the influences as a hole.

Growing community of inventors

Tokyo, Japan

Masafumi Nakada