Other

Ngk Insulators, Inc.

Ngk Optoceramics Co., Ltd.

Kazutoshi Tohyama

Masashi Fukuyama

Takashi Ota

Hitoshi Hasegawa

Akiyoshi Ide

Masahiro Maeda

A SiO &mdash;Al O &mdash;Li O component-based glass material, which comprises, as basic components, SiO : 60-63 wt %; Al O : 23-25 wt %; and Li O: 4-5 wt % and, as modifying components, ZrO : 1.5-2.5 wt %; TiO : 0.5-2.5 wt %; MgO: 0.5-1.5 wt %; ZnO: 0.5-1.2 wt %; Na O: 0.5-2.0 wt %; and K O: 0.5-2.0 wt %, and further comprises any one of BaO: 0.5-1.0 wt, CaO: 1.0-2.0 wt %, and B O : 0.01-1.0 wt %. This can be reheat-formed in a glass state and has a low thermal expansion coefficient.

Glass material and glass ceramic product

There is provided a thermally fused integral ferrule in which a first glass substrate is at least partly unitarily combined with a second glass substrates by means of thermal fusion. The first glass substrate includes optical-fiber fixing V-shaped grooves on its side opposed to the second glass substrate, and also includes on the optical-fiber fixing V-shaped grooves in the first glass substrate, a guide section having a predetermined void between the first and second glass substrates. The thermally fused integral ferrule is manufactured by contacting the surface to be thermally fused of the first glass substrate in which the optical-fiber fixing V-shaped grooves are formed, with the surface to be thermally fused of the second glass substrate, followed by thermal fusion of the surfaces of the first and second glass substrates at a temperature of (Tg &minus;100) to (Tg &plus;150)&deg; C. (where Tg is the glass transition temperature of one of the first and second glass substrates that is higher than that of the other and Tg is the lower glass transition temperature).

Thermally fused integral ferrule and its manufacturing method, and fiber array manufacturing method

On the pressing surface of a die, a first protrusion having a substantially triangular cross section and a second protrusion having a length which is greater than a width thereof and a substantially trapezoidal cross section in planes extending through both length and width dimensions thereof are provided. By press forming, a groove with a substantially V-shaped cross section to mount an optical part, and a groove with a substantially inverse-trapezoidal cross section providing an alignment marking are formed, being inverse-transferred in correspondence with the respective protrusions on one principal surface of a glass substrate. Forming such a pattern on a glass substrate produced with a die enables alignment of the glass substrate with a mask for photolithography with high accuracy.

Die and production method thereof, glass substrate and production method thereof and method of forming pattern on the glass substrate

A platinum thin film having a thickness of 0.01 to 5 &mgr;m is formed by means of the sputtering method on a press face of a die based on the use of a cemented carbide base material. A nickel thin film having a thickness of 0.05 to 0.5 &mgr;m and a thin film made of an alloy of platinum and iridium are allowed to intervene between the cemented carbide base material and the platinum thin film, if necessary. Alternatively, an alloy thin film having a thickness of 0.01 to 5 &mgr;m, which contains 10 to 70% by weight of iridium and 30 to 90% by weight of one or more species of metals selected from metals of the platinum group except for iridium, may be allowed to intervene between the cemented carbide base material and the platinum thin film.

Press-forming die for glass elements

There is provided a glass substrate having a V-groove portion for arranging an optical fiber core and a countersunk portion for containing an optical fiber coated portion, formed on the extension of the V-groove portion, on the surface thereof. The surface roughness of an inside side face of the countersunk portion is 1 &mgr;m or less in Rmax, or 0.2 &mgr;m or less in Ra at least at the connecting portion of the V-groove portion and the countersunk portion. The glass substrate is manufactured by a two-stage molding method in which a first molding step for forming a concave portion in the surface of a glass substrate molded body by grinding or pressing, and a second molding step for pressing the glass substrate molded body obtained by the first molding step from the top and bottom surfaces while reheating the molded body are performed.

Glass substrate and two-stage molding method therefor

A press mold for glass substrate includes an upper mold and a lower mold, and a pressure apparatus for applying pressure to the upper mold and the lower mold, for molding a plate-shaped glass substrate having a predetermined thickness between the upper mold and the lower mold. An engaging projected piece is projectingly provided on the side portion of the upper mold, an engaging projected piece supporting portion for supporting the engaging projected piece is provided on the side portion of the lower mold, and an end portion of the upper mold is formed so as to be released from the lower mold with the engaging projected piece as a rotating shaft. Variance in pressure on mold surfaces between the upper mold and lower mold is detected, and a buffer made of material having lower compressive yield strength than material constituting the lower mold is inserted between the lower mold and the pressure apparatus in a position corresponding to the mold surface portion at lower pressure. It is possible to prevent the molded object or the mold from being damaged, and to apply uniform pressure on an entire mold surface by eliminating pressure variance on the mold surface of the mold as far as possible, and therefore, a large glass substrate molded object of excellent quality can be molded.

Press mold for glass substrate

An optical fiber array includes an upper substrate and a lower substrate in which V-shaped grooves are formed, optical fibers being inserted and arranged in the V-shaped grooves. The tips of a plurality of protruding portions formed between the plurality of V-shaped grooves are shaped like planes. The optical fiber array can prevent optical fibers from being damaged or cut while preventing substrates from being cut when the fibers are placed in V-shaped grooves for alignment.

Optical fiber array

A heat-fused unitary ferrule includes a first glass substrate and a second glass substrate. The first glass substrate and the second glass substrate are unitarily joined by heat-fusion. A method for producing a heat-fused unitary ferrule includes the steps of: bringing a surface to be heat-fused of the first glass substrate having a groove for fixing an optical fiber into contact with a surface to be heat-fused of the second glass substrate; and subjecting the first and second glass substrates to heat-fusion at a temperature ranging from (Tg1-100).degree. C. to (Tg2+150).degree. C. (Tg1 denotes the higher glass transition temperature, and Tg2 denotes the lower glass transition temperature of the first and second glass substrates).

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Nakatsugawa, Japan

Kazutoshi Tohyama