Sumitomo Osaka Cement Co., Ltd.

Sumitomo Cement Co., Ltd.

Takashi Shinriki

Junichiro Ichikawa

Katsutoshi Kondou

Satoshi Oikawa

Toru Sugamata

Toshihiro Sakamoto

Hirotoshi Nagata

Futoshi Yamamoto

Masayuki Ichioka

Tetsuya Fujino

Tohru Sugamata

Yasuyuki Miyama

Masanao Kurihara

Manabu Yamada

Norikazu Miyazaki

Ryo Shimizu

Yoshihiro Hashimoto

Yasuhiro Ishikawa

Motohiro Takemura

Tsutomu Saitou

Junichiro Minowa

Shinichi Shimotsu

Junichi Ogiwara

Kazumasa Kiuchi

Masanobu Kobayashi

Hideki Honda

Jamshid Nayyer

An object of the present invention is to provide a manufacturing method of an optical waveguide element whose DC drift is suppressed, and to provide a manufacturing method of an optical waveguide element, capable of adjusting DC drift in the middle of manufacturing processes so as to improve a fabrication yield. The method of manufacturing an optical waveguide element comprises a step of forming an optical waveguide in a substrate having an electro-optic effect, a step of forming a buffer layer, and a step of forming an electrode, in which one stage or a plurality of stages of an interface diffusion layer heat adjustment step (S, S) for adjusting a concentration distribution of a specific substance in the buffer layer by heating is included after the buffer layer is formed.

Optical waveguide element and method of manufacturing the same

An optical waveguide device that uses a thin substrate having an electro-optical effect and a thickness of 10 &#x3bc;m or less, in which slab propagation light that is reflected from an end face of the device is removed and thus deterioration in an operational characteristic is suppressed. The optical waveguide device includes: a thin substrate which has an electro-optical effect and thickness of 10 &#x3bc;m or less, and in which an optical waveguide is formed; and a supporting substrate that is adhered to the thin substrate through an adhesion layer. An antireflective film is formed on a part of a side surface of the optical waveguide device.

Optical waveguide device

It is an object of the invention to provide a light modulator using a thin plate having a thickness of 20 &#x3bc;m or less and capable of stably holding a conductive film suppressing troubles such as resonance phenomenon of microwaves in a substrate and pyro-electric phenomenon and to provide a method of fabricating the light modulator. The light modulator includes: a thin plate () formed of a material having an electro-optic effect and having a thickness of 20 &#x3bc;m or less; a light waveguide () formed on the front or rear surface of the thin plate; and modulation electrodes () formed on the front surface of the thin plate to modulate light passing through the light waveguide. The light modulator further includes a reinforcing plate () bonded to the rear surface of the thin plate and a conductive film () continuously formed in the range from the side surface of the thin plate to the side surface of the reinforcing plate.

Light modulator and its fabrication method

An optical modulator is provided. The optical modulator includes a thin plate made of an electrooptic material and having a thickness of 20 &#x3bc;m or less, an optical waveguide formed on a top or bottom surface of the thin plate, and a modulation electrode formed on the top surface of the thin plate to modulate light passing through the optical waveguide, wherein, in a shape of the thin plate, a width of the thin plate at an optical input portion or optical output portion of the optical waveguide is two time or less the thickness of the thin plate.

Optical modulator

An optical modulator capable of efficiently separating radiation light and propagation light from each other or removing the radiation light in the optical modulator to suppress loss of the optical modulator and deterioration of an extinction ratio, including a thin plate of a material having an electrooptic effect and a thickness of 20 &#x3bc;m or less; an optical waveguide formed in a top surface or a bottom surface of the thin plate; and a modulation electrode formed in the top surface of the thin plate to modulate light which propagates in the optical waveguide, the optical waveguide has an optical junction portion in which a plurality of optical waveguide portions are joined together and, for shielding a portion of radiation light radiated from the optical junction portion, a concave portion or through-hole in the thin plate.

An optical modulator using a thin plate capable of improving an S/N ratio of an output light is provided. The optical modulator including a thin platehaving an electrooptic effect and having a thickness of 20 &#x3bc;m or less, an optical waveguideformed on a top or bottom surface of the thin plate, and a modulation electrode formed on the top surface of the thin plate to modulate light passing through the optical waveguide, wherein a stray light removing memberis disposed within the thin plate or in a vicinity of the thin plate.

An optical modulator in which stabilized driving is realized over a long time by relaxing stress generated in a recess formed in the surface of a substrate in the optical modulator and controlling deterioration of optical modulation control caused by stress-strain in the substrate including an optical waveguide. The optical modulator comprises a substrate of a material exhibiting electrooptic effect, an optical waveguide () provided on the substrate, and control electrodes (-) for controlling the phase of light being guided through the optical waveguide characterized in that a recess () is provided in the surface of the substrate for forming the control electrodes, and the control electrode () being formed on the recess is provided with a stress relaxing means.

The present invention intends to control DC drift phenomenon in a light control element having ridge structure, and to provide a light control element with high drive stability in a large area. The present invention has character that, in a light control element being equipped with a base plate that has an electrooptic effect, an optical guide and an electrode for modulation that are formed on said base plate, which has ridge structure, an anti-DC drift layer is installed on the surface of the above mentioned base plate where the optical guide is formed, and annealing treatment is performed after ridge processing.

Light control element

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 modulator including a substrate made of lithium niobate having an electrooptical effect, first and second optical waveguides formed in the substrate by effecting a thermal diffusion of titanium into a surface of the substrate, a buffer layer formed on the surface of the substrate, a hot electrode provided on the buffer layer and having a width W.sub.e not larger than a width W.sub.f of the optical waveguide, first and second ground electrodes provided on the buffer layer such that these ground electrodes are symmetrical with respect to the hot electrode, and an electric field adjusting region having a width not smaller than that of the hot electrode is provided between the buffer layer and the hot electrode. First and second ground side electric field adjusting main- and sub-regions may be provided between the buffer layer and the first and second ground electrodes, respectively. An interaction between an electric field generated by applied microwave and lightwave propagating along the optical waveguides can be enhanced, and thus a driving voltage can be decreased.

Optical modulator with optical waveguide and traveling-wave type

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.

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Tokyo, Japan

Takashi Shinriki