Sumitomo Electric Industries, Limited

Nippon Telegraph and Telephone Corporation

Doryokuro Kakunenryo Kaihatsu Jigyodan

Haruhiko Aikawa

Shinji Ishikawa

Hiroo Kanamori

Yoichi Ishiguro

Akira Urano

Toshio Danzuka

Katsuya Nagayama

Masumi Ito

Sumio Hoshino

Motonori Nakamura

Masahide Saito

Chisai Hirose

Ichiro Yoshimura

Nobuyuki Yoshizawa

Yutaka Katsuyama

Akira Inoue

Yuichi Ohga

Tadashi Enomoto

Masahide Saitoh

Nobuya Akaike

Takashi Matsuo

Chizai Hirose

Minoru Watanabe

Takashi Hasegawa

Motohide Yoshida

Koji Shimoda

Yoshiaki Ichige

Fumitoshi Okamoto

A concentric multi-tubular burner for synthesizing glass particles having a center port group constituted by a combination of jet ports of raw material gas, combustible gas and oxygen gas, wherein an outer wall of the oxygen gas jet port in the center port group protrudes more toward a burner head than an inner wall of the oxygen gas jet port. The flow rate of oxygen gas jetted from the oxygen gas jet port of the center port group is controlled to be in a proper range.

Burner for synthesizing glass particles and method for producing porous glass body

The present invention relates to a method of making an optical fiber product. In particular, this manufacturing method is characterized in that, between a drawing step in which a coated optical fiber comprising a glass fiber and a primary coating layer disposed around the outer periphery of the glass fiber is wound around a reel and a processing step in which the coated optical fiber wound around the reel is rewound around a bobbin, a control step is provided for holding the coated optical fiber wound around the reel in a place with a mean atmospheric temperature T (>0&deg; C.) for at least 30,000/T (hr) and, in the case where a coloring layer or the like is disposed around the outer periphery of the coated optical fiber, for at least 30,000/T (hr) but not longer than 210,000/T (hr). The optical fiber product such as a ribbon-type optical fiber obtained in consequence of this control step, effectively suppressed are increase in transmission loss caused by delamination between the glass fiber and the primary coating layer disposed around its outer periphery, and delamination of the coloring layer disposed around the outer periphery of the coated optical fiber or the like.

Method of curing coated optical fibers

A method for producing an oxide glass thin film is provided, in which volatilization of additives in a porous film from which the thin film is formed is effectively suppressed, and which the oxide glass film has a desired arrangement of refractive index with a low optical loss. According to this method, glass fine particles mainly containing SiO.sub.2 with a first additive are deposited on a substrate to form a porous thin film. A gas containing a second additive is supplied to a first chamber and heated to a first predetermined temperature profile to provide a heated gas containing an oxide. After disposing the substrate in a second chamber communicated with the first chamber, the substrate is heated to make the deposited porous glass into transparent glass while controlling a temperature in the second chamber according to a second temperature profile. A carrier gas is flowed from the first chamber to the second chamber to transfer the heated gas and oxide from the first chamber to the second chamber during heating. The temperature of the first predetermined temperature profile is maintained higher than the temperature of the second predetermined temperature profile at the same time. In addition, the heated gas contains a component that is also present in the first additive.

Method for producing glass thin film

An apparatus includes a first waveguide having a first surface having a first hole through which a fiber passes, and a second surface having a second hole through which an object passes and opposing the first surface, a magic tee connected to the first waveguide, and an adjustable short plunger connected to the magic tee.

Apparatus and method of manufacturing fiber

A process for forming film structure using Flame Hydrolysis Deposition (FHD) in which (1) glass soot is deposited on a substrate via FHD to form a first porous vitreous layer having a first bulk density, (2) a second porous vitreous layer having a second bulk density that is larger than the first bulk density is formed from a portion of the first porous vitreous layer, and (3) a third porous vitreous layer having a third bulk density is formed by depositing glass soot containing a refractive index increasing dopant on the second porous vitreous layer by FHD. The first, second and third porous vitreous layers are then heated to form an undercladding layer and a core layer, the undercladding layer being formed from the first and second porous vitreous layers and the core layer being formed from the third porous vitreous layer.

Method for fabricating an optical waveguide

In the method for forming an optical waveguide according to this invention, an optical waveguide comprising a core of quartz as a main component, and a cladding layers surrounding the core is formed by deposition of glass fine particles by flame hydrolysis deposition and vitrifying the glass fine particle layers. This method includes a step of transiently increasing a feed amount of phosphorus to a flame burner in forming glass fine particle layers to be the cladding layers. Feeding phosphorus in this step for the first time after a glass fine particle layer is deposited without feeding phosphorus to the flame burner, whereby generation of foreign objects near the core dan be suppressed. The method for fabricating an optical waveguide according to this invention is for fabricating a core 132a or cladding layers 122 142 surrounding the core 132a by flame hydrolysis deposition and is characterized in that the glass fine particle layers are vitrified after the deposition of the phosphorus-content glass fine particle layer, whereby glass films 122a, 122b with a thickness of below 10 .mu.m are formed. This glass film forming step is repeated twice or more times to form the core or the glass layers to be the cladding layers surrounding the core. This invention can suppress inhomogeneous vitrified films and especially can make phosphorus concentrations in the cladding layers uniform. As a result, prapagation losses can be made small.

Optical waveguide and method of fabricating the same

A method of producing an oxide glass thin film includes a process to obtain a transparent glass film, in which volatilization of additives in a porous film deposited is effectively suppressed and which can provide an oxide glass thin film having a desired arrangement of refractive index with a low optical loss. The method is for producing an oxide glass thin film, in which glass fine particles mainly containing SiO.sub.2 with additives are deposited on a substrate to form a porous thin film and then heated to form a transparent glass film. In the method, vapor of oxides of additive components is mixed in an atmosphere in which the porous thin film is heated to form the transparent glass film, whereby stopping the volatilization of the additives in the porous film deposited, preventing diffusion of the additives added to a core layer, and preventing the volatilization of glass transition temperature lowering components of additives (P.sub.2 O.sub.5, B.sub.2 O.sub.3, GeO.sub.2, etc.). By these, a desired arrangement of refractive index may be obtained, and an oxide glass thin film may be obtained while lowering the optical loss such as the optical scattering, which could be caused by bubbles in an unsintered portion.

Method for producing a glass thin film with controlloing an oxide vapor

In the first step, a fuel and raw material gases are fed to burner while flames from the burner scan a Si substrate. Synthesized fine glass particles are deposited on the substrate to form a first porous vitreous layer to be an under cladding layer. In the second step, the first porous vitreous layer is heated by the flames. A bulk density of an upper part of the first porous vitreous layer is raised to 0.3 g/cm.sup.3. Having a raised bulk density, this upper part functions as a shield layer against GeO.sub.2. In the third step, a second porous vitreous layer, to be a core layer, is deposited uniformly on the first porous vitreous layer. In the fourth step, the first and the second porous vitreous layers are sintered. In this case, the shield layer with a higher bulk density hinders the GeO.sub.2 component which has evaporated from the second porous vitreous layer from diffusing into the first porous vitreous layer.

A spectroanalyzer accurately spectroanalyzes in spite of the deterioration of transmissibility of an optical fiber (5) by radiation, by using a light from a sample cell (1) as a measurement light which passes through the optical fiber (5). The spectroanalyzer comprises a white light source (15) for directing a monitoring light to a one end (5b) of the optical fiber (5), and a half-mirror (3) arranged in front of the other end (5a) of the optical fiber (5) for reflecting the monitoring light, which is modulated to permit the discrimination thereof from the measurement light. Accordingly, a degree of deterioration of the optical fiber (5) can be determined from the monitoring light, and the affect of the deterioration of the transmissibility can be corrected by dividing a measurement light power by a monitoring light power so that the accurate measurement of the sample cell 1 is attained in spite of the deterioration of the transmissibility of the optical fiber (5).

Spectroanalyzer correcting for deterioration of transmissibility

There is provided an apparatus for the production of a hermetically coated optical fiber in which a glass preform for an optical fiber is melt drawn in a melt drawing furnace to produce a bare optical fiber which is passed to a reactor where a feed gas is supplied and the bare optical fiber is coated with a thin carbon coating made from the feed gas by the Chemical Vapor Deposition method characterized in that the reactor comprises an upper portion to which the feed gas is supplied, a middle portion in which the CVD method is substantially carried out and a lower portion from which an exhausted gas is withdrawn, and a cross sectional area of the middle portion perpendicular to a longitudinal direction of the optical fiber is larger than that of the upper portion.

Apparatus for the production of hermetically coated optical fiber

An apparatus for manufacturing a hermetically coated optical fiber having a single reaction chamber into which a fare fiber and raw gas are to be introduced for applying a hermetic coating to the bare fiber while the bare fiber passes through the reaction chamber is characterized by that the reaction chamber has a plurality of inlet tubes to introduce the raw gas, and the plurality of inlet tubes open to the reaction chamber at different positions from each other in a direction of movement of the bare fiber passing through said reaction chamber.

Method for manufacturing a hermetically coated optical fiber

A mass production method and apparatus of hermetic coating optical fiber where a bare fiber drawn from a preform is hermetically coated by CVD method in a reactor vessel, wherein a liquid flushes solid particles or by-products sticking to the reactor inner wall. The liquid may be supplied continuously or intermittently, to flush carbon particles generated during carbon coating process. The invention enables to produce a long hermetic coating optical fiber without choking the reactor, and improves a yield rate and productivity.

Apparatus of manufacturing hermetic coating optical fiber

A mass production method of hermetic coating optical fiber where a bare fiber drawn from a preform is hermetically coated by CVD method in a reactor vessel, wherein a liquid flushes solid particles or by-products sticking to the reactor inner wall. The liquid may be supplied continuously or intermittently, to flush carbon particles generated during carbon coating process. The invention enables to produce a long hermetic coating optical fiber without choking the reactor, and improves a yield rate and productivity.

Method of manufacturing hermetic coating optical fiber

A hermetic coated optical fiber is produced by preparing a bare optical fiber by melting and drawing an optical fiber preform in a fiber drawing furnace and introducing the bare optical fiber in a reactor in which a raw material gas is introduced and forming a hermetic coating film around a surface of the bare optical fiber by a chemical vapor deposition method or pyrolysis in the reactor, wherein a part of an inert gas for purging the fiber drawing furnace which has been heated by a heater equipped in the furnace is exhausted and a rest of the inert gas is introduced in the reactor for diluting the raw material gas.

Growing community of inventors

Yokohama, Japan

Haruhiko Aikawa