Abstract: An isothermal, low pressure-based process of depositing material within a substrate has been developed, and is particularly useful in forming an optical fiber preform results in creating an extremely narrow reaction zone within which a more uniform and efficient deposition will occur. Sets of isothermal plasma operating conditions have been found that create a narrow deposition zone, assuring that the deposited material is clear glass rather than soot particles. The exhaust end of the tube is connected to a vacuum system which is in turn connected to a scrubber apparatus for removal and neutralization of reaction by-products. The operating conditions are selected such that the hot plasma does not transfer a substantial amount of heat to the substrate tube, where the presence of such heat has been found to result in vaporizing the reactant material (creating soot) and developing hot spots.

Abstract: Provided is a manufacturing apparatus for manufacturing a porous glass base material by depositing glass particles, which has a chamber having air inlets, and an air distribution container having air outlets from which clean air is supplied to the air inlets.

Abstract: An isothermal, low pressure-based process of depositing material within a substrate has been developed and results in creating an extremely narrow reaction zone within which a more uniform and efficient deposition will occur. Sets of isothermal plasma operating conditions have been found that create a narrow deposition zone, assuring that the deposited material is clear glass rather than soot particles. The chemical delivery system, in one arrangement, utilizes rods of solid phase source material (which may otherwise be difficult to obtain in gaseous form). The operating conditions are selected such that the hot plasma does not transfer a substantial amount of heat to the substrate tube, where the presence of such heat has been found to result in vaporizing the reactant material (creating soot) and developing hot spots.

Abstract: A method and device for manufacturing a preform for optical fibres through chemical deposition on a substrate for deposition arranged vertically is described, comprising a chemical deposition chamber including at least one gripping member rotatably mounted about an axis Z-Z and adapted to hold at least one end of at least one elongated element constituting a substrate for chemical deposition for the formation of a preform for optical fibres. The chamber includes, moreover, at least one burner which is mobile along a direction Z substantially parallel to said axis Z-Z and adapted to deposit, on said at least one elongated element, a chemical substance for the formation of a preform and at least one suction element for collecting exhaust chemical substances, said at least one suction element being arranged on the opposite side to said at least one burner with respect to said axis Z-Z and being mobile along said direction Z.

Abstract: A device including at least one gripping member, rotatably mounted about an axis Z-Z, adapted to hold at least one end of at least one elongated element for chemical vapour deposition for forming a preform. The device includes at least one burner being mobile along a direction substantially parallel to the axis Z-Z and adapted to deposit, on the elongated element, a chemical substance for forming a preform, and at least one suction element arranged on the opposite side of the burner on a portion of a wall of the device on the opposite side of the gripping member from the burner. At least one air suction member, mobile along direction Z, is provided with motion synchronous with respect to the burner. The wall with the air suction member has a pair of respective upper and lower tapes rigidly associated with the burner.

Abstract: A device for manufacturing a preform of glass material for optical fibres. A chemical deposition chamber, at least one burner mobile along a direction Z and adapted to deposit a chemical substance on at least an elongated element positioned along an axis Z-Z, at least one suction element mobile along the direction Z for collecting exhaust chemical substances, a collector tube associated with the at least one suction element and adapted to discharge the exhaust chemical substances outside the chemical deposition chamber through an exhaust opening formed on a wall of the chamber, and a coupling device between the collector tube and the wall at the exhaust opening, allowing sliding of the collector along the direction Z and along a direction X towards/away from the axis z-z.

Abstract: An outside chemical vapor deposition apparatus is disclosed for depositing porous glass-forming material onto a target rod to form a cylindrical body, with substantially higher efficiency than could prior apparatus. The apparatus includes two separate burner arrays, one array optimized for depositing the material during an initial stage of the process, when the cylindrical body has a relatively small diameter, and the other array optimized for depositing the material during a later stage of the process, when the cylindrical body has a relatively large diameter. In addition, each burner array can include a plurality of burners, with each burner azimuthally angled relative to the apparatus' air-flow axis, and with adjacent burners angled in opposite directions relative to that axis, to minimize the density gradient within the deposited porous material.

Abstract: An apparatus and method for recovering and recycling a coolant gas from a heat exchanger. The apparatus comprises a coolant gas recovery section, and analysis section, and a coolant gas blending section. The coolant gas recovery section recovers a coolant gas containing contaminants from the heat exchanger. The analysis section monitors a condition of an analysis portion of the recovered coolant gas. The coolant gas blending section operates to produce, based on the condition of the recovered coolant gas monitored by the analysis section, a blend coolant gas comprising a virgin coolant gas and a reclaimed coolant gas that comprises at least a portion of the recovered coolant gas. The blend coolant gas has a predetermined contaminant concentration and is recycled into the heat exchanger. Thus, the coolant gas is recovered from, and recycled to, the heat exchanger at the predetermined contaminant concentration without using a purification device.

Abstract: A cap assembly for collecting cooling gas from a coolant chamber tube is disclosed. The cap assembly having connecting means and outlet means extending from its side walls being generally shaped and sized for detachable mounting on the body of the cooling gas chamber tube. The cap assembly is also employed in a hot optical fiber process which is being cooled by helium.

Abstract: An apparatus for manufacturing a glass base material, which is a base material of an optical fiber, comprising: a base rod, around and along which said glass base material is formed; a burner that hydrolyzes and accumulates a gas material, which is a base material of said glass base material, around and along said base rod; a first burner-moving-unit that moves said burner in a direction parallel with a longitudinal direction of said base rod; and a second burner-moving-unit that moves said first burner-moving-unit in a same moving direction of said first burner-moving-unit.

Abstract: An apparatus for manufacturing an optical fiber soot, which comprises a core partition having an opening portion at core burner side provided on a periphery of a core burner, in a reactor of the apparatus to be used in a conventional VAD method.

Abstract: A synthetic quartz glass preform is produced by flame hydrolysis with subsequent cooling and is suitable for the application of high-energy DUV radiation in the wave length range under 250 nm. The preform has a core area which contains ?1150 ppm OH, a strain double refraction of ?5 nm/cm and a resistance to high-energy DUV radiation as a result of a transmission reduction of ?T ?0.1%/cm thickness. The quartz glass has been exposed to the following radiation: wavelength ?1=248 nm, laser shot frequency ?300 Hz, laser shot value ?109 and lumination ?10 mJ/cm2, and wavelength ?2=193 nm, laser shot frequency ?300 Hz, laser shot value ?109 and lumination <5 mJ/cm2. Apparatus for producing the preform comprises a horizontally positioned muffle with two different sized openings facing each other. The larger of the openings is for removing the preform, the smaller opening being for introducing a burner. The internal chamber of the muffle narrows from the larger opening to the smaller opening.

Abstract: A device for manufacturing a preform of glass material for optical fibres. A chemical deposition chamber, at least one burner mobile along a direction Z and adapted to deposit a chemical substance on at least an elongated element positioned along an axis Z-Z, at least one suction element mobile along the direction Z for collecting exhaust chemical substances, a collector tube associated with the at least one suction element and adapted to discharge the exhaust chemical substances outside the chemical deposition chamber through an exhaust opening formed on a wall of the chamber, and a coupling device between the collector tube and the wall at the exhaust opening, allowing sliding of the collector along the direction Z and along a direction X towards/away from the axis z-z.

Abstract: A method and device for manufacturing a preform for optical fibres through chemical deposition on a substrate for deposition arranged vertically. A chemical deposition chamber includes at least one gripping member rotatably mounted about an axis Z-Z and adapted to hold at least one end of at least one elongated substrate for chemical deposition for the formation of a preform. The chamber includes at least one burner which is mobile along a direction Z substantially parallel to the axis Z-Z and adapted to deposit on the elongated substrate, a chemical substance for the formation of a preform and at least one suction element for collecting exhaust chemical substances. The suction element is arranged on the opposite side of the burner with respect to the axis Z-Z and is mobile along the direction Z and is positioned at a lower height than the burner.

Abstract: A chemical deposition chamber includes at least one gripping member rotatably mounted about an axis Z-Z adapted to hold at least one end of at least one elongated element for chemical vapour deposition for the formation of a preform. The chamber includes at least one burner which is mobile along a direction substantially parallel to the axis Z-Z and adapted to deposit, on the elongated element, a chemical substance for the formation of a preform, and at least one suction element arranged on the opposite side of the burner on a portion of a wall of the chamber on the opposite side of the gripping member from the burner. At least one air suction member, mobile along direction Z, is provided with a motion which is synchronous with respect to that of the burner. The chamber wall on which the air suction member is provided has a pair of respective upper and lower tapes rigidly associated with the burner.

Abstract: Systems and methods for treating spools of fiber using recycled gas. Spools of fiber are placed in chambers which can be sealed for exposure to the treatment gas. When a chamber is closed and sealed the treatment gas is pumped into the chamber to a specified pressure temperature and pressure to react with the fiber. Upon completion of the reaction the gas is pumped from the chamber in order to facilitate the removal of the treated fiber. The gas can be evacuated with a vacuum pump and compressed to be stored in a pressure vessel for reuse. At this time the gas may be analyzed. If the concentration of a component is too low, the gas may be vented or it may be enriched so that it may be recycled; otherwise it is compressed for storage and the process is repeated.

Abstract: A furnace is provided. The furnace includes a chamber for heating a portion of a preform to draw a fiber. The chamber has a melt region for melting the preform, and at least one port disposed proximate to the melt region. A purge gas supply is provided for supplying a purge gas into the chamber. The purge gas moves vapor products away from the fiber and exits the chamber through the at least one port.

Abstract: To provide an apparatus for manufacturing a glass particles deposit in which it is possible to effectively prevent the foreign matter from being deposited on or mixed into the glass particles deposit during the manufacturing operation. The apparatus for manufacturing the glass particles deposit comprises an upper funnel, a reaction vessel and a lower funnel, wherein the glass particulates are deposited around the outer circumference of a starting rod supported by a support rod within the reaction vessel while the starting rod is being rotated around its axis and reciprocated up and down, characterized in that a sleeve made of quartz separating an inner wall of the reaction vessel and a central rotation member is installed inside the reaction vessel.

Abstract: An object of the present invention is to reduce the adhesion of floating glass particulates to the surface of a soot preform during the manufacture of the soot preform, thereby reducing the voids generated in the transparent glass preform made from the soot preform, and to improve the quality of the optical fiber manufactured from the transparent glass preform. The equipment of the invention is equipped with a reaction vessel 1, a burner 2 provided within the reaction vessel 1 into which raw material gas and combustion gas are supplied so as to generate glass particulates by hydrolysis reaction, and a starting rod 5 onto which the glass particulates generated by the burner 2 are deposited. By drawing up the starting rod 5 while turning it around its axis, the glass particulates are deposited on the tip of or around the starting rod 5 to form a soot preform 6 in column-like shape.

Abstract: A process and apparatus are provided for applying a sizing composition to glass fibers with improved size application efficiency, while also providing for the collection and reuse of sizing composition, as well as for providing sizing composition to the applicator device, The apparatus includes a rotatable, but otherwise stationary, sizing applicator device which can be replaced without substantial interruption of the sizing application process while also providing a sizing reservoir for the collection and reuse of sizing composition, as well as for providing sizing composition to the applicator device.

Abstract: An apparatus for manufacturing a glass base material, which is a base material of an optical fiber, comprising: a base rod, around and along which said glass base material is formed; a burner that hydrolyzes and accumulates a gas material, which is a base material of said glass base material, around and along said base rod; a first burner-moving-unit that moves said burner in a direction parallel with a longitudinal direction of said base rod; and a second burner-moving-unit that moves said first burner-moving-unit in a same moving direction of said first burner-moving-unit.

Abstract: An apparatus for manufacturing a glass base material, which is a base material of an optical fiber, comprising: a base rod, around and along which said glass base material is formed; a burner that hydrolyzes and accumulates a gas material, which is a base material of said glass base material, around and along said base rod; a first burner-moving-unit that moves said burner in a direction parallel with a longitudinal direction of said base rod; and a second burner-moving-unit that moves said first burner-moving-unit in a same moving direction of said first burner-moving-unit.

Abstract: Vent holes are provided on a reaction vessel in the vicinity of burners which are placed in the reaction vessel. The gas of different flow rate and/or temperature is supplied through the vent holes toward a soot body in a length direction of the soot body.

Abstract: In an apparatus for producing glass particles deposit according to the present invention, a plurality of glass particle synthesis burners are placed on a front face of a reaction vessel, and at least one exhaust port is provided on a rear face of the reaction vessel. Two wall faces extending from both sides of the exhaust port and being in contact with two side faces of the reaction vessel are provided so that its contained angle is 90 degrees or less. Assuming that the shorter distance between the shortest distance from a rotation axis of a target rod to the side face of the reaction vessel and the shortest distance from the rotation axis of the target rod to the wall face is L, and the outer diameter of the glass particles deposit deposited on the target rod is d, L is greater than d.

Abstract: A device for manufacturing a preform for optical fibers is described, comprising a chemical deposition chamber including at least one gripping member rotatably mounted about an axis Z-Z and adapted to hold at least one end of at least one elongated element constituting a substrate for chemical deposition for forming a preform for optical fibers. The chamber further includes at least one burner which is mobile along a direction substantially parallel to said axis Z-Z and suitable for depositing, on said at least one elongated element, a chemical substance for forming a preform, and at least one suction element arranged on the opposite side to said at least one burner with respect to said axis Z-Z and adapted to collect and discharge, from said chemical deposition chamber, exhaust chemical substances.

Abstract: An apparatus for manufacturing a glass base material, which is a base material of an optical fiber, the glass base material having a core rod as a central axis, comprises a holding unit having a plurality of scroll chucks connected in series along the core rod for holding an end of the core rod; and a burner that hydrolyzes a gas material, which is abase material of the glass base material, into glass particles and accumulates the glass particles around the core rod to form the glass base material.

Abstract: An apparatus for manufacturing an optical fiber soot, which comprises a core partition having an opening portion at core burner side provided on a periphery of a core burner, in a reactor of the apparatus to be used in a conventional VAD method.

Abstract: In accordance with the invention, a preform from which fiber optics are drawn is fabricated by supplying reactants and gas vapors to the preform and by using two opposing forces to control the movement of a heat source supplying heat to the preform. The two forces function to reduce any hesitation or backlash in the movement of the heat source along predetermined portions of the preform to enable uniform layers to be formed within the preform.

Abstract: In a method of manufacturing a porous glass preform for an optical fiber which preform is formed as a deposit of fine glass particles by using a burner, a method to prevent the contamination of any glass particles having failed to be properly deposited so that the generation of voids may be minimized in a transparent glass preform which is produced by heating the porous glass preform. An inert gas is caused to flow through the burner at a rate of at least 25 m/s before fine glass particles are formed by the hydrolysis and/or oxidation of a glass material in a flame produced by the burner supplied with a mixture of a gas of the glass material and a gas for combustion and are deposited on a rotating starting member. It is desirable to elevate the pressure of the inert gas above the atmospheric pressure by a device connected to the burner by a pipeline, and cause it to flow rapidly through the burner.

Abstract: A pressure monitoring system for use in monitoring gas pressure within a rotating tube has a chemical delivery tube which projects into the rotating tube and whose distal end is sealed to the interior wall of the tube. A coaxial tube surrounds the delivery tube and forms a passageway between the two tubes which is in communication with the rotating tube interior through the seal mounting means. The gas pressure within the passageway is an indication of the pressure within the rotating tube, and is measured within a pressure monitoring unit which can control the pressure through the gas supply or through a low pressure device. In a second embodiment of the invention, a buffer gas supply coupling member is mounted to the coaxial tube and sealed to the exterior of the rotating tube to create a buffer zone. In a third embodiment of the invention, the buffer zone arrangement is modified to produce a more complete flow of buffer gases within the buffer zone.

Abstract: An apparatus for fabricating a soot preform for an optical fiber. The soot preform is fabricated by depositing glass particles on a starting rod capable of being rotated and pulled up. The apparatus comprises elements as follows. A reaction chamber is used for depositing the glass particles on the starting rod. An upper room is located above the reaction chamber for receiving the soot preform formed in the upper portion of the reaction chamber. At least one core burner is installed in the reaction chamber. A gas-supplying inlet is located in the top part of the sidewall of the reaction chamber closest to burner(s), and a gas-exhausting outlet is located in the top part of another sidewall opposite to the gas-supplying inlet. In addition, at least one cladding burner is installed in the reaction chamber.

Abstract: In furnaces for producing high purity fused silica glass boules, glass particles have a tendency to build-up adjacent the burner hole rim. It was discovered that unburned furnace gases containing silica particles where re-circulated in the furnace close to the burner hole rim and reacted with the oxygen of infiltrated air adjacent the burner hole, and thus deposited such particles in the form of a glassy build-up about the rim of the burner hole. In order to eliminate the source of oxygen adjacent the burner hole rim, a curtain of an inert gas is caused to flow through the burner hole between the sidewalls of the burner hole and the flame of the burner. Accordingly, the curtain of inert gas inhibits the combustion of the unburned hydrogen and carbon monoxide furnace gases adjacent the exit rim of the burner hole and thereby minimizes glass build-up about the burner hole rim.

Abstract: A method and apparatus for producing a glass base material for an optical fiber. A material for an optical fiber and a reaction gas are jetted from a burner connected to a material line and a gas line toward a surface of a quartz substrate, in order to deposit a soot-like reaction product on the substrate at a predetermined position to thereby produce a glass base material for an optical fiber. Dry air is introduced into a reaction container in an amount of 4 to 8 times the amount of water vapor that is generated due to flame hydrolysis during the reaction.

Abstract: One aspect of the present invention is a film applicator for applying a coating to at least a portion of a surface of fibers, comprising: an enclosure having a reservoir to store a coating composition; a roller having a generally cylindrical surface positioned within the enclosure such that a first portion of the roller surface is immersed in the coating composition and a second portion of the roller surface extends through an opening in the enclosure to contact fibers; a drive to rotate the roller within the enclosure such that the surface of the roller can be coated with a film formed from the coating composition; and a bar positioned at least in close proximity to the roller surface, the bar having a contoured surface that provides a desired film thickness on the roller surface.

Abstract: A method and apparatus for manufacturing optical fibers provided with hermetic coatings, wherein the bare fiber made from a heated preform advances through a stream of reactive gaseous medium which flows at a constant speed in the direction of advance of the fiber, which is then accelerated, and which is finally removed remote from the fiber by a stream of inert gas flowing in the opposite direction from the direction of the stream of reactive gaseous medium. Application is to manufacturing optical fibers for telecommunications.

Abstract: A coated optical fiber is produced by the steps of cooling through a cooling assembly an optical fiber obtained by drawing, heating and spinning an optical fiber base material and thereafter coating the optical fiber with a resin wherein a gas mixture including an He gas and possible ambient air is sucked out of the cooling assembly and purified to collect the He gas to be a recovery gas of He which is to be recycled to the cooling assembly together with a pure He gas, but the gas mixture sucked out of the cooling assembly is compressed and stored until the gas mixture reaches a predetermined pressure or more and then purified when it reaches the predetermined pressure while the compressed gas mixture is returned to an upstream side of a compressor which serves to compress the gas mixture so that the flow quantity of gas suction varies in accordance with the flow of He gas supplied to the cooling assembly whereby the gas mixture from the cooling assembly is prevented from lowering an He gas concentration of t

Abstract: To draw an optical fiber (10) from one end of a glass preform (9) which is heated to above the glass softening temperature at least in that area, a gas (21) flows around the preform (9) into a furnace space (16) during the drawing process and subsequent feeding of the preform. During the feeding, the areas that are adjacent to the drawing end of the preform (9) pass through gas zones in which the helium content of the furnace gas increases in the drawing direction.

Abstract: An apparatus for manufacturing an optical fiber preform, comprising a reaction vessel housing a core, combustion burners each arranged such that a flame spurting port thereof is positioned within the reaction vessel so as to generate fine glass particles by a flame hydrolysis reaction, and a discharge unit including a discharge port arranged on a side of the reaction; vessel for discharging the excess fine glass particles which were not deposited on the core and the waste gas out of the reaction vessel, wherein an angle formed between an imaginary plane including the flame spurting port of one of the combustion burners and another imaginary plane including the discharge port of the discharge unit falls within a range of between 0.degree. and 40.degree..

Abstract: Energy efficient apparatus for forming migration free glass fiber packages composed of fibers bearing substantially uniform coatings of size composition. Heated air from around the fiber forming bushing is drawn into a chamber through which the glass fibers pass to cause the water or solvent in the applied size to be evaporated. The flow of heated air through the chamber is regulated so as to obtain substantially uniform size application to the fibers.

Abstract: A thread is formed of one or a plurality of fans of continuous filaments on which a sizing composition is deposited. The moisture content on the thread is controlled by subjecting the fans of filaments to a current of air transversely to the direction of movement of the filaments between the zone in which the size is deposited and the zone in which the filaments are gathered together.

Abstract: An apparatus (10) is provided for producing continuous glass filaments (30). The apparatus (10) comprises a bushing (20) for supplying streams of molten glass and a drawing device (40) adapted to draw the streams into continuous glass filaments (30). A cooling device (50) is also provided and is located adjacent to the bushing (20) for drawing in heated air from a filament forming area beneath the bushing such that heat is convectively transferred away from the filament forming area.

Abstract: The present invention relates to a process for producing a porous glass preform for an optical fiber and an apparatus for conducting such a process. According to the process, fine glass particles are produced by heating and reacting vaporous starting materials in a reaction vessel. The resulting fine glass particles are thereafter deposited to obtain the porous glass preform. An exhaust gas containing non-deposited fine glass particles is exhausted through an exhaust duct at a velocity above 15 m/sec. Preferably, pressure fluctuation in the reaction vessel is minimized by supplying air from outside of the reaction vessel to the exhaust duct. In accordance with the present invention, the exhaust duct is less likely to become obstructed by non-deposited fine glass particles. As a result, the preform can be produced without interruption over an extended period of time.

Abstract: A fiberglass product usable as an end product or an intermediate product is formed as a pack in a forming station but only 1/7th of the conventional quantity of binder is applied. After curing to a self-sustaining form, additional binder is added in an amount in excess of the amount required in the final product and then the excess binder and moisture is removed by one or more stripping steps. Additional moisture is removed by electronic means to the desired moisture level for commercial products.

Abstract: Disclosed is a method and apparatus for providing reactant vapors to a utilization site. The apparatus includes a vaporization chamber enclosed by top and bottom walls, side walls and first and second end walls. The first end wall is elevated with respect to the second end wall. The reactant is supplied in liquid form to a flow distributor that delivers the liquid to that portion of the bottom wall near the first end wall. The angle with which the bottom wall is inclined with respect to horizontal is sufficient to cause the liquid to flow down the bottom wall at a rate sufficient to form a film, the thickness of which is smaller than that thickness which would support a bubble during heating of the film. The surface is heated to a temperature greater than the boiling point of the liquid, thereby converting the liquid reactant to a vapor that is delivered to the vapor utilization site.

Abstract: 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.