Shin-etsu Chemical Co., Ltd.

Other

Seiki Ejima

Shinji Makikawa

Jun Abe

Akira Ikushima

Takumi Fujiwara

Nobuyasu Mantoku

Masaaki Shirota

Kazuo Koya

Shigeru Konishi

Yasushi Maeda

Tsuneo Mori

Masaharu Horiguchi

Hiroshi Aoi

Sayuri Maeda

A method for manufacturing a synthesized silica glass optical member, the method comprising: providing a porous silica glass body; heating the porous silica glass body in an atmosphere containing hydrogen or oxygen, and sintering the porous silica glass body in an atmosphere containing fluorine compound. Furthermore, a synthesized silica glass optical member manufactured by the method.

Synthesized silica glass optical member and method for manufacturing the same

There is disclosed a method for producing a base material for optical fiber having a deformed first clad consisting of at least a core, a first clad and a second clad, comprising a step of deforming a shape of a section of the first clad so that it may have at least one linear part when the first clad is formed around the core, a step of depositing porous glass fine particles as the second clad made of the same material as that of the first clad on a glass rod having the deformed first clad to form a porous glass base material, and a step of forming the second clad having a round section by vitrifying it. There can be provided a method for producing a base material for optical fiber wherein a lot of breakages or cracks on the surface of the base material can be prevented in a step of depositing porous glass fine particles for the second clad on the first clad, and base material for optical fiber having no defects, and an optical fiber having an efficient effect of being excited with excitation light.

Method for producing base material for optical fiber having deformed first clad, base material for optical fiber and optical fiber

An optical waveguide substrate is prepared by forming grooves in a silicon substrate in accordance with the pattern of a desired waveguide device, thermally oxidizing the silicon substrate to form a peripheral quartz layer surrounding the grooves, burying in the grooves a doped quartz glass layer having a higher refractive index, abrading the surface of the resulting structure to be flat, and forming on the flat surface a glass layer having a lower refractive index. An optical waveguide substrate featuring no distortion of the core pattern, little warp, and a low loss can be produced in a simple manner.

Method for preparing optical waveguide substrate

There is disclosed second-order nonlinear glass material wherein a part having second-order nonlinearity contains Ge, H and OH and has second-order nonlinear optical constant d of 1 pm/V or more, and a method for producing second-order nonlinear glass material comprising treating a porous glass material containing Ge with hydrogen, sintering it and subjecting it to a ultraviolet poling treatment. There can be provided second-order nonlinear glass material having second-order nonlinearity which is a sufficiently high and has a sufficiently long lifetime for a practical purpose, in use of the glass material for optical functional elements or the like.

Method for producing a second-order nonlinear glass material

A method of making a high quality optical waveguide substrate is provided, in which the surface of a silicon substrate is oxidized through relatively large thickness and no foreign matter particles are adhered on the surface thereof. The silicon substrate to form a quartz film for the optical waveguide is mounted on a carbon contained ceramics sample base and is inserted into a carbon contained ceramics furnace core tube of which its external circumference is arranged in a heating furnace. When the inside of the furnace core tube is heated to 200 to 600&deg; C. by the heating furnace, an oxidant gas for the silicon substrate surface is introduced, then by further heating up to 1200 to 1350&deg; C., the silicon surface is thus oxidized.

Method for making an optical waveguide substrate

A silicon substrate is prepared by furnishing a silicon substrate ( ) having a step ( ) of at least 5 &mgr;m high on one surface, forming by high pressure heat oxidation an oxide film ( ) which is thinner than the step, and removing the oxide film on the higher surface region until the silicon surface is exposed in the higher surface region while leaving the oxide film on the lower surface region. Because of excellent electrical properties, minimized warpage, a substantially constant oxygen concentration, and a definitely ascertainable oxide-silicon boundary, the silicon substrate is suitable for use in optical waveguide devices.

Preparation of silicon substrate

There is disclosed second-order nonlinear glass material wherein a part having second-order nonlinearity contain Ge, H and OH and second-order nonlinear optical constant d of 1 pm/V or more, and a method for producing second-order nonliner glass material comprising treating a porous class material containing Ge with hydrohen, sintering it and subjecting it to a ultraviolet poling treatment. There can be provided second-order nonlinger glass material having second-order nonlinearity which is a sufficiently high and has a sufficiently long lifetime for a practical purpose, in use of the glass material for optical elements or the like.

Second-order nonlinear glass material

A mask having a center hole for passing through a center fiber, which is one of multiple fibers, and multiple surrounding holes for passing through surrounding fibers, which are the remainder of the multiple fibers, and a stress adjusting unit for holding stresses generated in the center fiber and surrounding fibers to a desired constant value, respectively, are installed. The surrounding fibers are rotated around the center fiber by rotating the mask. The center fiber and the surrounding fibers that have been twisted around the center fiber are heated with a heating apparatus and drawn. The center fiber and the surrounding fibers are fixed using a clamp installed between the stress adjusting unit and the heating apparatus.

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Annaka, Japan

Seiki Ejima