Nippon Telegraph and Telephone Public Corporation

Nippon Telegraph and Telephone Corporation

Nitto Electric Industrial Co., Ltd.

Sumitomo Electric Industries, Limited

Japan Synthetic Rubber Co., Ltd.

Takao Kimura

Nobuo Inagaki

Mitsuo Yoshihara

Shinzo Yamakawa

Fumihiko Kato

Yoshio Kawai

Akinobu Tanaka

Yasuyuki Inoue

Toru Yamanishi

Yasufumi Yamada

Masayuki Okuno

Kuniharu Kato

Fumio Yamamoto

Hiroshi Ban

Takeshi Kitagawa

Shuichi Shibata

Jiro Nakamura

Fumiaki Hanawa

Shigeki Sakaguchi

Hisaaki Okazaki

Masaharu Horiguchi

Hisao Takata

Ryotaro Ohono

Yoshito Shuto

Makoto Wagatsuma

Tetsuo Yoshizawa

Toru Maruno

A resist material comprises a polysiloxane obtained by hydrolysis and condensation with dehydration of one or more alkoxysilanes having an oxirane ring, or of a mixture of the alkoxysilane(s) having an oxirane ring and one or more alkoxysilanes having no oxirane ring, and an acid generator. The resist material may contain one or more of a spectral sensitizer, an organic polymer having a hydroxyl group or an epoxy compound. Resist patterns are formed by coating an organic polymer on a substrate and then the resist material on the film of the organic polymer to form a two layer resist having a bottom layer of the organic polymer and top layer of the resist material, prebaking, imagewise exposing high radiation, postbaking, and developing the resist with alkaline solutions to remove an unexposed portion of the top layer, and dry etching the bottom layer using the relic of the resist material as a mask. the temperature of the post baking is preferably lower than that of the prebaking.

Negative working resist material, method for the production of the same

A guided-wave circuit module includes a guided-wave circuit chip having an input waveguide part and an output waveguide part at the ends thereof, a guided-wave circuit part having a predetermined function and positioned between the input waveguide part and the output waveguide part; and a holder for supporting the guided-wave circuit chip, wherein the guided-wave circuit part of the guided-wave circuit chip does not come in contact with the chip holder; at least part of the input and output waveguide parts of the guided-wave circuit chip is fixed to the holder with a fixing agent; and the packaged chip does not have a warp which leads to deterioration of characteristics. A fixing agent having a high hardness is applied to the periphery of the endfaces of the input and output waveguide parts of the guided-wave circuit module and to the periphery of the fiber endfaces of the optical fiber array connected to the module. Therefore, these endfaces can accurately be polished and the waveguide can be connected to the optical fibers at a sufficiently low fiber connection loss and a high return loss.

Guided-wave circuit module and wave-guiding optical component equipped

Processes for preparing oxide powders and superconducting oxides

A coated optical fiber comprising an optical fiber; a first layer of a thermoplastic rubber composition which is disposed around the circumference of the optical fiber, has a Young's modulus of 0.1 GPa or less, and is capable of extrusion coating; and a second layer of a thermoplastic resin composition which is disposed around the circumference of the first layer, has a linear expansion coefficient of 1.times.10.sup.-5.degree. C..sup.-1 or less and a Young's modulus of 5 GPa or more, and is capable of extrusion coating. The coated optical fiber has excellent transmission characteristics at low and high temperatures and is inexpensive.

Coated optical fiber, fabrication process thereof and fabrication

A UV-ray curable resin composition comprising a polyurethane derived from a polyether polyol and a diene polymer having hydroxyl group, said polyurethane having polymerizable double bond different from the carbon-carbon double bonds contained in said diene polymer having hydroxyl group, and a coated optical fiber having a coated layer comprising the cured product of said resin composition. This composition has good coating characteristics, and the cured product thereof has small modulus over a wide temperature range and good hydrolysis resistance, and water absorption resistance. The coated optical fiber has small transmission loss over a wide temperature range and has high strength even in water.

UV-ray curable polyurethane composition and coated optical fiber

A coating material for optical glass fibers is disclosed. The material is comprised of 1,4-polybutadienes having functional groups or modified polybutadienes derived from the 1,4-polybutadienes having introduced therein polymerizable double bonds different from the double bonds present in the 1,4-polybutadienes.

Optical fibers coated with modified 1,4-polybutadienes

Coated optical glass fibers are described, wherein the coating composition comprises an unsaturated polyester containing at least one of (1) polyethylene glycol or polypropylene glycol having an average molecular weight of from 200 to 1,000 as a glycol component, (2) a long chain saturated aliphatic dibasic acid containing 12 or more carbon atoms as saturated polybasic acid component, and an acrylate or methacrylate, and (3) a long chain saturated aliphatic dibasic acid containing 6 or more carbon atoms as a saturated polybasic acid component and a long chain aliphatic dihydric alcohol containing 4 or more carbon atoms as a glycol component; and an acrylate or methacrylate.

Coated optical glass fibers and method for production thereof

A process for producing an optical fiber is described, wherein a fiber that has been drawn from a glass preform is coaed with a resin composition curable with heat, ultraviolet rays, or electron beams, and then cured, wherein before the drawn fiber contacts another solid object, the fiber is cooled by being passed through a cooling means filled with a non-reactive liquid material which is the same as said resin composition except that it is free from any compound that catalyzes curing of the resin, selected from among a curing agent, a cross-linking agent, curing catalyst, curing accelerator, sensitizing agent and a reactive diluent, and then the fiber is coated and with said resin composition and cured.

Process for producing a glass fiber for light transmission

In a process for preparing optical fibers, an optical fiber preform is heated and softened to be drawn at a high speed into an optical fiber. The optical fiber is passed through a plastic pipe of a thermoplastic resin. As the optical fiber is passed through the plastic pipe, the lower part of the plastic pipe is gradually inserted into a heating unit to be uniformly heated. The heated plastic pipe is softened and is coated over the optical fiber.

Method for coating optical fibers with thermoplastic resin

Growing community of inventors

Mito, Japan

Takao Kimura