Hitachi, Ltd.

International Business Machines Corporation

Hitachi Medical Corporation

Tadashi Fukuzawa

Naoki Chinone

Takashi Kajimura

Michiharu Nakamura

Kenji Hiruma

Kazuhisa Uomi

Hiroyoshi Matsumura

Kazuo Sekiya

Susumu Takahashi

Hitoshi Nakamura

Toshio Katsuyama

Teruki Suzuki

Eizaburo Yamada

Yutaka Takahashi

Kensuke Ogawa

Shinji Tsuji

Hiroaki Inoue

Tsukuru Ohtoshi

Masaki Hasegawa

Motohisa Hirao

Shinkichi Tanimizu

Hiro Munekata

Teiji Hisano

Satoru S Kano

Hiroyoshi Matumura

Hideaki Matsueda

Robert Dennis Miller

Yoshihisa Fujisaki

Yuichi Ono

John Campbell Scott

Sally Ann Swanson

Koji Ishida

Ken Yamaguchi

Victor Y Lee

Shinichi Nakatsuka

Shigeru Sato

Shigeo Yamashita

Akira Tonomura

Yasutoshi Kashiwada

Katsutoshi Saito

Shin'ichi Nakatsuka

Franklin M Schellenberg

Emilio E Mendez

Hisao Nakashima

Sayuri Kohara

Yuuichi Ono

Kiyoshi Kumata

Junichi Umeda

Koichi Ikarugi

Ling Y Liu

Tetsuji Morita

Hiroshi Watabe

Yasuyuki Takahashi

Yasuji Ozawa

Victor Yee Way Lee

Shigeo Shionoya

Akio Oishi

An optical link module of the present invention for connecting light beams by deflection and including light-emitting devices arranged in a planar manner; an optical fiber bundle that is an optical waveguide for receiving the light beams from the light-emitting devices, and an optical turn which includes a plurality of aspherical lenses which are disposed between the light-emitting devices and the optical fiber bundle and are formed while corresponding to the number of the light-emitting devices and the number of optical fibers.

Optical link module, optical interconnection method, information processor including the optical link module, signal transfer method, prism and method of manufacturing the prism

Provided is an optical transmission substrate including: a first substrate; an optical waveguide which has clad covering a core and a periphery of the core and extends on an upper surface of the first substrate; a second substrate provided parallel to the first substrate so that a lower surface thereof contacts an upper surface of the optical waveguide; a reflection surface which is provided on a cross section of the core at an end of the optical waveguide and reflects light, which travels through the core of the optical waveguide, toward the second substrate; and a light guide which is provided in the second substrate and guides the light, which is reflected toward the second substrate, toward an upper surface of the second substrate from a position closer to the core than an upper surface of the clad.

Optical transmission substrate, method for manufacturing optical transmission substrate and optoelectronic integrated circuit

Novel liquid crystal display (LCD) structures for full-color liquid crystal displays using photoluminescent (PL) fibers. The new architectures simplify the LCD fabrication process by replacing complicated, time consuming photolithography steps for color filter fabrication to a low-cost, high-throughput fiber spinning technology. The new LCD architecture implementing the approach has a higher power efficiency than conventional LCDs. Three structures of LCD devices utilizing photoluminescent (PL) fiber arrays includes: a first structure having PL fiber arrays situated behind the LC shutter (relative to viewers); a second structure having PL fiber arrays situated on top of the LC shutter; and a third structure where the PL fiber arrays are located outside the LC cell. In one of these structures, the fibers not only photoluminesce, but also polarize incident light thus reducing LCD fabrication cost.

Energy-efficient full-color liquid crystal display

A white cold-cathode fluorescent lamp, which is used as an illumination backlight for liquid crystal, is replaced by cold-cathode fluorescent lamps that emit red, green and blue lights, respectively. Since a liquid crystal picture is illuminated by the fluorescent lights in a time-sequential manner, a multi-color display can be provided without spatially dividing liquid crystal pixels using a color filter; and as it is not necessary for one pixel to be divided into three color cells, the size of a pixel can be reduced. Furthermore, in the liquid crystal display device, a phosphor having a short emission life is employed to coat the interior of the cold-cathode fluorescent lamp and enable the cold-cathode fluorescent lamp to be turned on and off rapidly, so that degradation of display colors due to slow fluorescence decay can be prevented and moving pictures can be displayed.

Liquid crystal display device having red, green, and blue fluorescent lamps having a particular phosphor composition or a double tube lamp

An optical system is provided in which flare is prevented and, when the light reflected from a reflection component is modulated by a photoelastic phenomenon, the effect of the modulation on the measurement of the intensity of the reflected light can be eliminated, and, further, a flying height tester for a magnetic head is provided using such optical system. A multilambda plate is provided in the flare-prevention optical system for allowing the light reaching a reflection component and the light reflected from the reflection component to pass, and for allowing the phase difference between the ordinary ray and the extraordinary ray to vary by 2.pi. or more depending on the wavelength of light. Since the light passed through the multilambda plate only varies in the peak position and the peak height varies little even if the light has experienced modulation, no error occurs in the spectrum intensity of the light. A depolarizer may be substituted for the multilambda plate.

Flare-prevention optical system, flare-prevention method, and flying

A nonlinear optical device comprising a substrate and a film structure coated on to the substrate. The film has, in a direction normal to the substrate, an intercalation structure including a semiconductor layer and an organic layer that lave different energy gaps. The intercalation structure includes a plurality of semiconductor layers and a plurality of organic layers which comprise a quantum well system. The film structure includes an assembly of microcrystals having domain size smaller than that of the wavelength of light with which the device operates. The microcrystals have an axis aligned in a direction normal to the substrate and have randomly oriented axes in a direction parallel to the substrate. A method for producing the device comprises providing a solution of an organic material in a solvent and placing a quantity of the solution on a substrate to form the organic material film structure thereon. The film is formed by spin coating of the solution on the substrate. Preferably the film is comprised of a two-dimensional perovskite such as (C.sub.10 H.sub.21 NH.sub.3).sub.2 PbI.sub.4. The solvent is acetone or dimethoxyl ethane.

Nonlinear optical device and method of manufacturing same

This invention provides a method and apparatus for accurately measuring the flying height of a magnetic head at high speed by using a white lamp and a color CCD camera. The invention entails substituting tentative refraction coefficients and extinction coefficients representative of colors in theoretical equations expressing the relationship between interference light intensity and flying height, thereby optimizing the parameters by non-linear regression. The flying height of a magnetic head is measured by using the coefficient thus determined. Also, this invention enables determination of flying height at very high speed through effecting the above optimization in consideration of constants associated with the shape of the head under consideration, and adapting the above theoretical equations.

Method and apparatus for measuring the flying height of a magnetic head

The present invention is the use of coupled quantum wells in the active region of a semiconductor laser to modulate the frequency and amplitude of the light output of the laser. In a particular embodiment of the present invention the coupled quantum wells are contained in a graded index of refraction semiconductor double heterostructure laser. The active region of this tunable laser consists of two quantum wells having a width of approximately 50 Angstroms or less which are separated by a barrier layer having a width of approximately 20 Angstroms or less. The quantum well material is intrinsic GaAs and the barrier layer is Al.sub.x Ga.sub.1-x As wherein x=0.23. The active region is surrounded by the double heterostructure in which one side is doped p-type and the second side is doped n-type. The resulting laser is a p-i-n type structure. A reverse bias with respect to the flat band voltage of the p-i-n structure is applied across the p-i-n structure which modulates both the frequency and the intensity of the laser output. The tunable laser is pumped with a variety of conventional means, including both electrical and optical pumping. The modulation of the wavelength is approximately linear over a 1.5 volt operating range. A tunable laser, such as the present invention, having an output wavelength modulated by an electric field is useful in the field of optical communications and computing.

Coupled quantum well tunable laser

Disclosed is a new method suitable for making highly integrated quantum wire arrays, quantum dot arrays in a single crystal compound semiconductor and FETs of less than 0.1 micron gate length. This makes it possible to construct a high-performance electronic device with high speed and low power consumption, using a combination of low-temperature-growth molecular beam epitaxy (LTG-MBE) and focused ion beam (FIB) implantation. The compound semiconductor (GaAs) epitaxial layers, which are made by LTG-MBE, are used as targets of Ga FIB implantation to make Ga wire or dot arrays. Precipitation of arsenic microcrystals, which are initially embedded in a single crystal GaAs layer and act as Schottky barriers, are typically observed in an LTG GaAs layer. A thermal annealing process, after implantation, changes the arsenic microcrystals to GaAs crystals if the arsenic microcrystals are in the region in which the Ga ions are implanted. A wire-like shape free of As microcrystals then acts as a quantum wire for electrons or holes whereas a dot-like shape free of As microcrystals acts as a quantum dot. The co-existence of Ga ions and dopant ions, which provides conductivity type carriers opposite to the conductivity type of the majority carriers of a channel region of an FET, provides the fabrication of very narrow junction gate region for any FET.

Fabrication method for quantum devices in compound semiconductor layers

Fabrication of quantum devices in compound semiconductor layers and

An apparatus for changing the direction of an optical beam comprises a thin film grating deflector; an optical energy source for providing optical energy to strike the deflector at a first angle with respect to gratings of the deflector and to exit the deflector at a second angle with respect to the gratings; and elements for applying a voltage to the deflector to vary the second angle. The optical energy source preferably comprises a laser diode; and a collimator for coupling energy from the laser diode to the grating deflector. The grating deflector is a planar waveguide including a plurality of stacked quantum wells formed of GaAs separated by barriers of AlGaAs. Optical energy provided to the grating deflector in a first direction is deflected in a second direction. These directions define a plane in which the waveguide is disposed. The quantum wells are stacked in a direction perpendicular to a plane of the waveguide. The optical energy source, the thin film grating deflector, the voltage applying elements and the collimator may be integrated into a single chip.

Optical beam deflector

Growing community of inventors

Tokyo, Japan

Tadashi Fukuzawa