Sumitomo Osaka Cement Co., Ltd.

Nec Corporation

Sumitomo Cement Co., Ltd.

Other

Hirotoshi Nagata

Junichiro Ichikawa

Takaaki Ogata

Kaoru Higuma

Yasuhisa Taneda

Yasuyuki Miyama

Toshihiro Sakamoto

Takashi Shinriki

Masaru Shiroishi

Junichiro Minowa

Nobuhide Miyamoto

Tsutomu Saito

Takashi Tateyama

Mithuru Sakuma

Ryosuke Kaizu

Manabu Yamada

Ryo Shimizu

Susumu Murata

Futoshi Yamamoto

Tetsuya Fujino

Shinichi Shimotsu

Makoto Shimada

Junichi Ogiwara

Jamshid Nayyer

Hideki Honda

Masanobu Kobayashi

Kazumasa Kiuchi

Naoki Kougo

A first film () is formed between a substrate () and a signal electrode (); ground electrodes () and () which constitute an optical waveguide device (), and a second film () is formed between the substrate () and a signal electrode (); ground electrodes () and (). An optical phase modulator (A) is composed of the substrate (), an optical waveguide (), the signal electrode (), the ground electrodes () and (), and the first film (). An optical intensity modulator (B) is composed of the substrate (), the optical waveguide (), the signal electrode (), the ground electrodes () and (), and the second film (). The optical waveguide device () is composed of the optical phase modulator (A) and the optical intensity modulator (B), which are integrated monolithically.

Optical waveguide device

There is provided a high performance optical waveguide type optical modulator with excellent long term reliability, in which contamination of the buffer layer in a forming process of a signal field adjustment region on the buffer layer by a lift-off method or an etching method, is prevented and DC drift thus suppressed. The optical waveguide type optical modulatorcomprises a substratehaving an electro-optic effect, optical waveguidesformed on the surface of this substratea traveling-wave type signal electrodeand ground electrodeswhich are provided on the substrateand control a lightwave, and a buffer layerprovided between the electrodesand the optical waveguidesand furthermore, a dielectric layeris provided on the entire surface of the buffer layeron the side of the electrodesand a signal field adjustment regionwhich has a wider width than that of the traveling-wave type signal electrodeand is made of a material with a higher refractive index than that of the dielectric layeris formed between the dielectric layerand the traveling-wave type signal electrode

Optical waveguide type optical modulator and production method therefor

An optical waveguide is formed on a substrate made of a material with an electro-optic effect. Then, an intermediate layer is fabricated, on the main surface of the substrate, by a dielectric material selected from the group consisting of AOx, B Oy, COz (A: divalent element, B: trivalent element, C: quadrivalent element, 0<x<1, 0<y<3, 0<z<2, O: oxygen). Then, a metal-cladding type optical polarizer is fabricated on the intermediate layer and the optical waveguide. A buffer layer is formed and partially removed by non-reactive dry-etching to form a first opening. Subsequently, a metal-cladding type optical polarizer is fabricated inside the first opening, and a signal electrode and a ground electrode, constituting a modulation electrode, are fabricated on the buffer layer.

Optical waveguide device and method for forming optical waveguide device

An electro-optic element comprising a ferroelectric substrate comprising a single crystal having an electro-optic effect, in which an optical waveguide is formed by thermal diffusion of titanium in a main face, and in which an axis in which said electro-optic effect is induced is parallel to said main face; a heat treated buffer layer provided on said ferroelectric substrate on a side in which said optical waveguides are formed; electrodes provided on a part of the buffer layer; and a protective film for preventing contamination of the buffer layer provided on at least the region of the buffer layer on which the electrodes are not formed.

Electro-optical element having protective film on top and side surfaces of buffer layer

The object of the present invention is to provide a light limiter which can control the generation of an optical surge, comprises few components, and has high reliability; in order to achieve the object, the light limiter of the present invention comprise a parametric amplification element parametrically amplifying an input signal light, and a wavelength selection element removing a wavelength component, excepting a specified wavelength, from among the signal light output from said parametric amplification element.

Light limiter

The optical fuse of the present invention comprises: at least one light heatable portion for receiving an incident beam, and at least one thermally sensitive degradable portion with transparency and reflectivity, positioned in contact with the light heatable portion. The light heatable portion contains a light heatable material which generates heat depending on a specified light intensity of the incident beam. The thermally sensitive degradable portion contains a thermally sensitive degradable material which loses or reduces its transparency and reflectivity, depending on the heat generated by the light heatable portion when the light intensity of the incident beam exceeds a threshold value.

Optical fuse

Light intensity attenuator and attenuating method

An optical element-optical fiber composite structure having a high resistance of the optical fiber to breakage due to cyclical change in temperature, includes a package structure having a main container, side containers attached to the main container and sleeves through which a main chamber of the main container is connected to side chambers of the side containers; an optical element housed in the main chamber; and optical fibers introduced into the main chamber through the side chambers and the sleeves and connected to the optical element.

Package structure for optical element and fibers and composite structure

An optical waveguide device usable as an optical wave-modulator and having a reduced DC drift includes a LiNbO.sub.3 substrate, an optical waveguide formed in a front surface portion of the substrate, a dielectric layer covering the front surface of the substrate and the optical waveguide surface, and an electrode system arranged on the dielectric layer, the dielectric layer comprising a matrix component consisting of an amorphous SiO.sub.2 and a doping element component consisting of Li and/or Nb; and having a refractive index lower than that of the amorphous SiO.sub.2 matrix free from the doping element component.

Optical waveguide modulator having a reduced D.C. drift

A jacket layer of a jacketed optical fiber is cut by a cutting method and apparatus in which (A) a terminal portion of a jacketed optical fiber is straightened and grasped by a fiber holder, and (B) a blade device having (a) a pair of cutting blades and (b) a blade holder in which device cutting edges of the blades are arranged in such a manner that the edges are opposite to each other through a gap left therebetween and are on one and the same plane, the straightened portion of the jacketed optical fiber extends at a substantially right angle to the plane, and a center line of the gap between the cutting edges intersects an axis of the straightened portion of the jacketed optical fiber, and is moved in at least one direction at a substantially right angle to the axis of the straightened portion of the jacketed optical fiber to cut the secondary coating layer at a depth equal to or larger than the thickness of the secondary coating layer but smaller than the total thickness of the primary and secondary coating layers.

Cutting method and apparatus for removing a secondary coating layer from

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Funabashi, Japan

Hirotoshi Nagata