Hitachi Cable, Inc.

Nkk Corporation

Hitachi, Ltd.

Other

Nippon Telegraph and Telephone Corporation

Hitachi Metals, Ltd.

Tatsuo Teraoka

Yoshiyuki Hiramoto

Shigeo Toya

Yasunori Yoshie

Hirokazu Shiga

Takeshi Kato

Hisato Uetsuka

Koichi Abe

Koji Sasaki

Satoshi Aoki

Masahiro Yanagisawa

Masahiro Aoki

Yoshitada Oshida

Yasufumi Yamada

Masao Tachikura

Hiroshi Kajioka

Satoru Kikuchi

Hiroaki Okano

Noribumi Shiina

Yasunori Iwafuji

Hideki Nounen

Koichi Maru

Yuuetsu Takuma

Masahiro Okawa

Kazuya Murakami

Keiichi Higuchi

Mitsumasa Zobuchi

Fumi Miyata

Shin-ichi Kajiyama

Koudo Yamada

An optical fiber end processing method includes fixing two portions of an optical fiber, heating and fusing the optical fiber between the two fixed portions, to form a first heat fusion region, heating and fusing the optical fiber fixed between the two fixed portions unit while fixing the two fixed portions, moving a heat fusion unit from a side of the first heat fusion region toward a base end side of the optical fiber, and pushing a heat fusion portion of the optical fiber in a direction of shortening a length of the heat fusion portion, to form a second heat fusion region continuous to the first heat fusion region and in which the air holes of the optical fiber disappear; and removing the first heat fusion region by cutting the optical fiber within the second heat fusion region after the second heat fusion forming.

Optical fiber end processing method and optical fiber end processing apparatus and optical fiber end

An optical wavelength multiplexer/demultiplexer includes a substrate, an input channel waveguide, an input slab waveguide, a channel waveguide array which has a plurality of channel waveguides, each channel waveguide differing in length from its neighboring waveguide by predetermined amount, an output slab waveguide, and a plurality of output channel waveguides. The input slab waveguide or output slab waveguide have a temperature compensation material, in its light path, having an opposite sign of diffraction temperature change to the plurality of channel wave guides, or a material capable of canceling a change in the in-phase plane of light having each wavelength which occurs in a vicinity of the channel waveguide array and the slab waveguide, or a waveguide for band width adjustment on which a waveguide to adjust band width of wavelength multiplexing light is provided.

Optical wavelength multiplexer/demultiplexer

An optical assembly has a substrate and an optical device chip. On mutually opposed surfaces of the optical device chip and the substrate, indexes having slope faces are formed. Index passage alignment is performed by using the indexes as positioning reference and by using image measurement.

Alignment of an optical assembly

An optical waveguide 3 comprises a substrate like a Si substrate having a projection with a flat surface and inclined side surfaces thereon, a buffer layer having a refractive index of n.sub.0 formed on lower surfaces of the substrate, a secondary buffer layer having a refractive index of n.sub.0 formed on the buffer layer, a core waveguide having a refractive index of n.sub.1 formed on the secondary buffer layer and a cladding layer having a refractive index of n.sub.0 covering the core waveguide. The flat surface of the projection 31 is exposed through an opening. The secondary buffer layer controls a transmission loss increase caused by partial thickness differences of the ground buffer layer or scattering by scratches or strains created by the grind.

Optical waveguide, method of making the same and integrated optical

In an optical fiber array structure, a ferrule is provided around an optical fiber array. The ferrule has an outer configuration defined by combination of, preferably, two circles. Thus, eye glass-shaped outer configuration is obtained for the ferrule. The adapter has an aperture for receiving the ferrule, and the aperture has an inner configuration which is complementary with the outer configuration of the ferrule.

Optical fiber array structure

Each fiber-optic gyroscope unit is shaped like a tetragonal cone. A square plate (51) is used as a base which holds a light source module (52), a light receiving unit (detector) (53) and an optical fiber coil (54). Directional couplers (56a), (56b) are also mounted on the base (51). A phase modulator (55) which includes a piezoelectric element is disposed inside the optical fiber coil (54). A signal processing circuit board (58) which has pedestals (59) stands on the base (51) such that it positions above the optical fiber coil (54). A polarizer (510) is wound around the optical fiber coil (54). A reinforcement member (511) is also provided. All these components are so arranged as not to extend out of the tetragonal cone (OABCO*) which defines its own unit region. Three identical fiber-optic gyroscope units are combined by connecting members (512, 513, 514) to form a single fiber-optic gyroscope to detect rotational angular velocities about three orthogonal axes. Since identical units ( 50) are used, the assembly is easy, and since the three units (50) are combined with respect to the axis of symmetry, the combined units (50) form a compact gyroscope.

Multi-axis fiber-optic gyroscope assembly in which each gyroscope

A method of manufacturing a metal pipe clad cable having a fiber with an excess length housed therein, comprises the steps of preparing a metal pipe clad cable comprising a metal pipe and a fiber housed in the metal pipe, and passing said metal pipe clad cable through a plurality of sets of bending rolls. The metal pipe is repeatedly bent when passing through the plural sets of said bending rolls so as to generate a plastic deformation within the metal pipe and, thus, to impart an excess length to the fiber within the metal pipe.

Method of forming cladded cable having fiber with excess length enclosed

Metal pipes containing optical fibers are connected to each other directly or indirectly by use of a sleeve. In case of using the sleeve, the sleeve is connected at one end to one of the metal pipes, after the optical fibers are connected. Then, the sleeve is elongated by a predetermined length, so that the sleeve is connected at the other end to the other metal pipe. Consequently, no tensile stress resides in the connected optical fibers in the connected structure. When the metal pipes are connected directly to each other, one or both of the metal pipes are elongated, after the optical fibers are connected. Then, the metal pipes are connected by use of the elongated portions. Consequently, the same result is obtained as using the sleeve.

Method for connecting optical fibers sealed in metal pipes

Metal pipes containing optical fibers are connected to each other directly or indirectly by use of a sleeve. In case of using the sleeve, the sleeve is connected at one end to one of the metal pipes, after the optical fibers are connected. Then, the sleeve is elongated by a predetermined length, so that the sleeve is connected at the other end to the other metal pipe. Consequently, no tensile stress resides in the connected optical fibers in the connected structure. When the metal pipes are connected directly to each other, one or both of the metal pipes are elongated, after the optical fibers are connected. Then, the metal pipes are connected by used of the elongated portions. Consequently, the same result is obtained as using the sleeve.

Connection structure of optical fibers sealed in metal pipes and method

Two opposite portions of the surface of a core rod whose section is circular are removed by machining in the longitudinal direction thereof, so that the section of the core rod is transformed into a non-circular shape. On the surface of the thusly shaped non-circular core rod, glass particulates are accumulated, and then the glass particulates accumulated on the core rod are sintered to create a preform. Then, the preform is heated and drawn, so that a polarization-maintaining optical fiber of non-circular section is obtained.

Method of manufacturing polarization-maintaining optical fibers

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Hitachi, Japan

Tatsuo Teraoka