Abstract: The invention relates to an apparatus (1) for tensile testing of an optical fiber (11). In order to efficiently and simply test the optical fiber, the apparatus comprises a dual pulley (6) with a first circumferential surface (7) having a first diameter (D1) and with a second circumferential surface (8) having a second diameter (D2) which is larger than the first diameter (D1). A fiber inlet (10) which is delimited by the first circumferential surface (7) and the first drive belt section (2) contacts the first circumferential surface (7). A fiber outlet (13) which is delimited by the second circumferential surface (8) and the second drive belt section (3) contacts the second circumferential surface (8), and a guide (12) passes the optical fiber (11) from the fiber inlet (10) to the fiber outlet (13).

Abstract: The present invention provides an apparatus and a method for fabricating a glass rod from a glass preform capable of suppressing a diameter fluctuation of the drawn glass rod even when there is a relatively large diameter reduction ratio between the glass preform and the glass rod, such as 60 to 95%. The feed speed V1 of the glass preform is set to a constant value, the diameter D of the glass preform is acquired for determining the drawing speed V2 from diameter data of the glass preform measured before being drawn at a diameter acquisition position defined with respect to a reference position of the furnace. The distance from the reference position to the diameter acquisition position is defined so as to vary depending on a diameter fluctuation of the glass preform before being drawn in a longitudinal direction thereof.

Abstract: In an apparatus for conveying a glass tube strand or glass rod strand having a cross-section that is different from a circular cross-section, in particular having an oval cross-section, a plurality of support and guide members are arranged, if viewed in the direction of movement of the glass tube strand or glass rod strand, one after the other such that the moving glass tube strand or glass rod strand is directly supported thereon and guided by them. The support and guide members are disposed tilted in said direction of movement so that the moving glass tube strand or glass rod strand is directly supported on edges of the support and guide members. Thus, one-sided heat losses due to heat dissipation via the support and guide members can be significantly reduced to thereby reduce the curvature of the glass tube strand or glass rod strand.

Abstract: In an optical fiber manufacturing method, the cooling device and the coating device are connected in an airtight manner and by preventing a cooling gas, flowing inside the cooling device, from flowing into the coating device by a meniscus of resin inside of the coating device, a flow of the cooling gas inside the cooling device is discharged to an outside of an upper end of the cooling device as an upward stream; helium gas as the cooling gas flows into a lower portion of the cooling device and carbon dioxide gas as the cooling gas which is separated from the helium gas flows into a side lower than a position where the helium gas flows in, during the forcible cooling; and a flow rate of the helium gas and a flow rate of the carbon dioxide gas are individually controlled.

Abstract: When a GRIN lens fiber is drawn from a preform, control of a fiber diameter is improved in order to increase a production yield of the GRIN lens fiber having a fiber diameter within a desired range. The problem is solved by controlling the drawing speed using a fiber diameter c, which is obtained by correcting a fiber diameter a using the fiber diameter b and a fiber diameter ?. The fiber diameter a is measured using a diameter measuring instrument A that measures an outer diameter of the GRIN lens fiber, which is being elongated inside a heating furnace, the fiber diameter b is measured using a diameter measuring instrument B that measures an outer diameter of the GRIN lens fiber outside the heating furnace, and the fiber diameter ? is a value of the fiber diameter a measured a specified period of time T earlier.

Abstract: In an optical fiber drawing device of the present invention, as an operational parameters corresponding to the real drawing speed in the duration from the moment of starting the operation of the optical fiber drawing device till the moment of reaching the target drawing speed are extracted from operational parameters stored in a operational parameter storage unit and applied to the optical fiber drawing device. The operational parameters include a base preform feeding speed, a target variation of real drawing speed, a gain multiplied by the speed element related with the variation of the real drawing speed, an operation cycle, a drawing furnace temperature, a coating resin pressure to coat the optical fiber, and flow of cooling gaseous helium, etc.

Abstract: A glass base material elongating method of sequentially feeding rod-like glass base materials hung by a glass base material feeding mechanism into a heating furnace, and pulling a glass rod with a smaller diameter by a pulling chuck at a lower part of the heating furnace, includes: aligning, by an alignment guiding device that guides the glass rod, a guiding center of the alignment guiding device with an axis of the glass rod, the alignment guiding device guiding the glass rod between the heating furnace and the pulling chuck.

Abstract: A process for manufacturing a composite yarn including continuous glass filaments intermingled with continuous organic thermoplastic filaments and an apparatus for implementing the process. The continuous glass filaments come from a bushing and are separated into plural sheets. The continuous organic thermoplastic filaments come from a spinning head and are separated into plural sheets. The thermoplastic filaments are thrown into the glass filaments so as to mingle them, in a ratio of at least one sheet of thermoplastic filaments in each sheet of glass filaments, the mingled filaments then being gathered into at least one composite yarn.

Abstract: The present invention provides an apparatus and a method for fabricating a glass rod capable of suppressing a diameter fluctuation of a drawn glass rod even in a case of a relatively large diameter reduction ratio between a glass preform and a glass rod, such as 60 to 95%. The diameter (D) of the glass preform for determining the ratio from a measured diameter data is acquired, the measured diameter data is obtained by measuring a diameter of the glass preform before being drawn along a longitudinal direction of the preform, and the feed speed (V1) is determined so that the feed speed (V1) varies depending on a fluctuation of the measured diameter data in the longitudinal direction.

Abstract: The present invention provides a apparatus and a method for fabricating a glass rod capable of suppressing a diameter fluctuation of a drawn glass rod even in case of a relatively large diameter reduction ratio between a glass preform and a glass rod, such as 60 to 95%. A feed speed V1 of the glass preform is set to a constant value, a diameter D of the glass preform is acquired for determining the drawing speed V2 from a measured diameter data of the glass preform before being drawn at a diameter acquisition position defined with respect to a reference position of the furnace, and a distance from the reference position to the diameter acquisition position is defined so as to vary depending on a diameter fluctuation of the glass preform before being drawn in a longitudinal direction thereof.

Abstract: A method for producing a glass fiber, through longitudinally drawing a preform in a drawing kiln, wherein cooling the glass fiber is performed in at least three time periods, wherein the glass fiber is exposed to a first time based cooling rate above a crystallization temperature range, to a second time based cooling rate that is greater than the first time based cooling rate within the crystallization temperature range, and to a third time based cooling rate which is smaller than the second time based cooling rate below the crystallization temperature range.

Abstract: An apparatus and method for tapering an optical fiber segment having an initial radial profile to substantially conform to a pre-specifiable desired radial profile for controlling mutually coordinated elongation and softening of different axial portions of the segment according to control parameters derivable based on a normalized axial coordinate reference by which points of the initial profile map to corresponding points of the desired profile. The softening and/or elongation may progress substantially in either a step-wise, time-discrete manner or time-continuously. The invention is useful for forming tapered fused couplers as well as for tapering individual fibers.

Abstract: A strand forming and chopping apparatus includes a bushing for forming a continuous strand, a size applicator for applying a size to the strand, a chopping device for chopping the strand into individual segments and a thread-up apparatus for directing the strand into the chopping device. The thread-up apparatus includes a cot incorporating a cot shoe and a strand guide displaceable between a rest position and a thread-up position where the strand guide holds the strand in a feed position from which the strand is engaged by the cot shoe and delivered to the chopping device.

Abstract: Methods for producing optical fibers along nonlinear paths include incorporating fluid bearings. An optical fiber is drawn from a preform along a first pathway, contacted with a region of fluid cushion of a fluid bearing, and redirected along a second pathway as the fiber is drawn across said region of fluid cushion.

Abstract: A non-contact method for measuring the tension applied to a drawn optical fiber includes drawing an optical fiber and displacing the optical fiber by applying a pressurized fluid to the optical fiber. The pressurized fluid may be applied to the optical fiber using a fluid bearing. The fluid bearing may include a fiber support channel. The optical fiber may be directed through the fiber support channel and is displaced relative to the fluid bearing by supplying the pressurized fluid to the fiber support channel. The displacement of the optical fiber caused by the application of the pressurized fluid to the optical fiber may then be measured. The tension applied to the optical fiber may then be determined based on the determined displacement.

Abstract: A device for making up a plurality of synchronously produced individual optical fibers includes a drawing installation for drawing the fibers and a take-up winder for winding up the fibers on a take-up spool. The drawing installation provides an identical and constant drawing rate for each of the fibers. The take-up winder has a compensating device to compensate for differences in speed of the fibers between the drawing installation and the take-up spool. Fluctuations of the fiber diameter during production of the fibers are avoided and the fibers are passed at a substantially constant rate to the take-up winder. A fiber bundle can be made up without influencing the drawing rate, thereby also avoiding reactions on the melting process when drawing the fibers from a heated preform. A method for making up a plurality of synchronously produced individual optical fibers is also provided.

Abstract: Disclosed herein are an apparatus and method for manufacturing a flat panel display device. The apparatus and method for manufacturing a flat panel display device contribute to a compact apparatus for etching a substrate and damage or breakage prevention of the substrate during the transfer of the substrate by virtue of stoppers. The etching apparatus comprises a loader for loading or unloading a substrate, an etching device for etching the substrate into a desired shape, a DI rinsing device for rinsing fine particles and etchant generated during the etching process from the etched substrate, an air knife for drying the rinsed substrate, and one or more turn stages provided at one or more locations between the above respective devices, and adapted to change a transfer direction of the substrate.

Abstract: In a known method for producing tubes of quartz glass, a hollow cylinder (2) of quartz glass is continuously supplied to a heating zone (1) and is softened therein in regions, and a tube strand (21) is drawn off at a drawing speed from the softened region with formation of a drawing bulb (26), and the tubes to be produced are cut to length in the form of tube strand pieces by separating the tube strand (21) at a desired separation point (T, Vu, Vo) and an internal pressure differing from the external pressure applied to the outer cladding is maintained in the inner bore (4) of the hollow cylinder (2) in that the inner bore (4) of the tube strand is provided with a flow obstacle.

Abstract: An apparatus and method for tapering an optical fiber segment having an initial radial profile to substantially conform to a pre-specifiable desired radial profile for controlling mutually coordinated elongation and softening of different axial portions of the segment according to control parameters derivable based on a normalized axial coordinate reference by which points of the initial profile map to corresponding points of the desired profile. The softening and/or elongation may progress substantially in either a step-wise, time-discrete manner or time-continuously. The invention is useful for forming tapered fused couplers as well as for tapering individual fibers.

Abstract: A method and a system based on the method imparts to an optical fiber a predetermined rotation about its axis, wherein the fiber is rotated by way of a frictional force acting on the fiber while it is advanced in a predetermined direction. The rotation actually imparted to the optical fiber is measured on-line while the fiber is advancing in the direction and the frictional force is controlled responsively to the measured rotation so as to obtain the predetermined rotation. Spinning devices acting on the optical fiber by way of an externally controllable frictional force and particularly suitable to be used with the method are disclosed.

Abstract: A method for manufacturing an optical fiber comprises setting a heating condition for heating a glass rod, which is a parent material of the optical fiber, and an elongating speed of the glass rod based on a prescribed numerical value which changes with a progress of elongation of the glass rod; heating and elongating the glass rod to generate a preform based on the heating condition and the elongating speed which are set by the setting; and drawing the preform to a filament-like form by further heating the preform to generate the optical fiber.

Abstract: A method for manufacturing a glass rod (106), which is a parent material of an optical fiber (350), comprising: adjusting a vertical inclination of a standard rod (138) having a predetermined straightness; and heating and elongating a base material (102), which is a parent material of the glass rod (106), along an axis of the standard rod (138), the vertical inclination of which is adjusted, to generate the glass rod (106).

Abstract: An electric furnace extending method and apparatus for an optical fiber glass body alignment when connecting the extension use body and pulling member and making it possible to immediately start the extension after the fusing of the connection portion. A centering mechanism for centering the free end portion of the body and member on the furnace center side is provided between the furnace pipe of the electric furnace and grips of the extension use glass body and between the furnace pipe and the pulling member. The free end portion is centered by this centering mechanism, then the gripped sides of the body and member are fixed, the front ends of the two free end portions are abutted and fused and bonded at the highest temperature portion inside the electric furnace, then the highest temperature portion is moved to the extension portion of the glass body side and the extending of the glass body is commenced.

Abstract: An optical fiber drawing installation is equipped with an oscillating pulley that applies torsion to the fiber alternately in one rotation direction and then in the opposite direction. To control the torsion applied to the fiber, images are formed of the fiber and the pulley. The images are analyzed to determine the position of the fiber relative to the pulley. The torsion is calculated from the calculated position, on the assumption that the fiber rolls on the pulley.

Abstract: In method of making an optical fiber and an apparatus, an optical fiber coated with UV curable resin is drawn at a drawing speed of 1000 m/min or more so that the optical fiber 5 has predetermined coating diameter from 235 &mgr;m to 265 &mgr;m. A transit time from an exit of a UV curing furnace to an entrance portion of a capstan for pulling the optical fiber downstream is set to be 0.5 seconds or more.

Abstract: Apparatus and methods allow fused bi-conical couplers to be pulled to reduced diameters to exposes more of the evanescent field in the coupled region. First and second stages hold the fibers on either side of the fused region, with at least one of the stages being moveable relative to the other. A furnace positioned relative to the fused region, and a tensometer is used to determine the tension of the fibers between the stages. A controller is provided to monitor the tension on the fibers and increase the distance between the stages when the tension falls to a predetermined threshold. As the fibers are pulled, light begins to couple from one fiber to the next, leading to five distinct crossover regions. The tension is continuously monitored, and when the tension drops below each threshold, the furnace is slowly pushed back to maintain the tension by decreasing the heat on the fiber from the furnace. As the fiber is pulled through these crossover areas, the coupling region decreases in diameter.

Abstract: After the start of the control operation of a drawing apparatus, the operation control of a line speed being the drawing-in speed of an optical fiber is performed by a line speed control unit (19), and an optical-fiber feed speed control is performed by a preform feed speed control unit (22), in order that an optical fiber outside diameter measured by an optical-fiber outside diameter measurement unit (8) may become a target outside diameter. By way of example, in a case where the distal end of an optical fiber preform is not in a shape steadily melted in a heating furnace, the preform speed control unit (22) controls the feed speed of the optical fiber preform in the three stages of an optical-fiber-preform initial feed speed control, an acceleration-associated preform feed speed control and a line speed-associated preform feed speed control.

Abstract: The invention concerns a system for making clipped thermoplastic yarns, such as chipped glass yarns comprising at least a die (1) co-operating with at least a cutting machine (7) located in the extension of each other, means (3) for sizing the yarns (5) and/or filaments (2) coming from the die (1), at least one return means (4), a floor. The invention is characterised in that the system further comprises means (74) for displacing and positioning the cutting machine (7) in at least two positions: the first beneath said floor (9), the second above said floor (9), and a first opening (10) in the floor (9) through which the cutting machine (7) is moved.

Abstract: A method and apparatus for sintering a large-sized optical fiber preform without the occurrence of a large difference of diameters in a longitudinal direction, a non-solidified portion in a solidified portion of a porous soot body and a drop of the optical fiber preform. In response to a relative position of a sintering position of a porous soot body in an optical fiber preform to a sintering zone, in other words, in response to either of a lower end, an intermediate portion or an upper end of the optical fiber preform in the sintering zone, a controller controls at least one of a sintering temperature of an electric heater, a moving speed of the optical fiber preform and a supply gas flow supplying to the sintering zone.

Abstract: The invention is directed to a method of apply controllable pneumatic force in a multibarrel pipette puller to pull single and multibarrel pipettes. A multibarrel pipette puller has a top mechanical portion and a bottom control box. In the top mechanical portion, a metal base is mounted with a pneumatic cylinder, a linear motion guide rail with its movable block connected a clamp body, a pneumatic rotator connected a drill chuck and a pair of heater fixture located between the clamp body and the drill chuck. An optical grid plate is attached on side of the clamp body. An optical sensor is mounted on the metal base along side of the optical grid plate moving path. The piston rod of pneumatic cylinder is connected to the clamp body to deliver pulling and pushing force. The rotator can turn the drill chuck up to 180 degree clockwise or turn counter clockwise back to original position. Both the cylinder and rotator are actuated by pressured air.

Abstract: A method for manufacturing an optical fiber comprises setting a heating condition for heating a glass rod, which is a parent material of the optical fiber, and an elongating speed of the glass rod based on a prescribed numerical value which changes with a progress of elongation of the glass rod; heating and elongating the glass rod to generate a preform based on the heating condition and the elongating speed which are set by the setting; and drawing the preform to a filament-like form by further heating the preform to generate the optical fiber.

Abstract: A method for manufacturing an optical fiber comprises setting a heating condition for heating a glass rod, which is a parent material of the optical fiber, and an elongating speed of the glass rod based on a prescribed numerical value which changes with a progress of elongation of the glass rod; heating and elongating the glass rod to generate a preform based on the heating condition and the elongating speed which are set by the setting; and drawing the preform to a filament-like form by further heating the preform to generate the optical fiber.

Abstract: A test optical fiber section (F) that resides under tensile stress (F) is heated in at least one longitudinal location so that a constriction (&Dgr;d) of its outside circumference forms thereat. This constriction (&Dgr;d) is acquired and utilized for setting welding parameters.

Abstract: Method for winding a fiber element onto a support. The fiber element having at least two longitudinal portions (Pi) with different characteristics. The method including the steps of supplying the fiber element to the support and associating with each longitudinal portion a respective value of the winding pitch (pi) which is different from the values associated with the portions adjacent thereto. The winding pitch associated with each portion being modulated in accordance with a periodic function.

Abstract: The present invention provides a fiber optic draw furnace having a fiber optic heating and draw control system that controls the heating of a fiber optic preform which is partially melted by a furnace and the drawing of an optical fiber from the fiber optic preform by a fiber drawing device. The fiber optic heating and draw control system features a fiber optic heating and drawing device controller that responds to a furnace power consumption control signal from a fiber optic preform heating device in the furnace, for providing a furnace heating control signal to the fiber optic preform heating device in the furnace and a fiber tension draw control signal to the fiber drawing device to maintain a desired fiber draw tension on the optical fiber. In one embodiment, the fiber optic heating and drawing device controller is a programmable logic controller.

Abstract: The present invention provides a fiber optic draw furnace having a fiber optic heating and draw control system that controls the heating of a fiber optic preform which is partially melted by a furnace and the drawing of an optical fiber from the fiber optic preform by a fiber drawing device. The fiber optic heating and draw control system features a fiber optic heating and drawing device controller that responds to a furnace power consumption control signal from a fiber optic preform heating device in the furnace, for providing a furnace heating control signal to the fiber optic preform heating device in the furnace and a fiber tension draw control signal to the fiber drawing device to maintain a desired fiber draw tension on the optical fiber. In one embodiment, the fiber optic heating and drawing device controller is a programmable logic controller.

Abstract: In the manufacturing of optical fiber preform with excellent accuracy of outer diameter made of the rod as drawn from synthetic quartz ingot, the outer diameter measuring devices 67 and 68 measure the outer diameters of the cone 2 and rod 3 drawn from the ingot 1, and the drawing speed is controlled based on the measured outer diameters. The optical fiber preform manufacturing apparatus that finishes the rod into truly round form without any curve has a rotary holding means 13 and 14 that hold the rod 3 resulting from the heating and drawing of the ingot 1 rotating it in synchronization with the rotation of the ingot 1, a comparison device 18 that outputs a signal after comparing the outer diameter of the cone 2 as measured by the outer diameter measuring device 11 with that of the referential circle, a control device 19 that controls the rotational amount of the rotating device 10, and a control device 20 that controls the rotational amount of the rotary holding device 13 and 14.

Abstract: A glass blank is sent to a heating zone where it is softened region by region and drawn continuously in a controlled manner as a drawing bulb is formed. Estimates of at least one controlled variable are predicted free of dead time; in addition, at least one geometric variable of the component which can be correlated with the controlled variable is measured continuously, and the measurement values thus obtained are used to adjust the predicted estimates. On the basis of the predicted estimates thus adjusted, the nominal-actual deviation of the controlled variable is determined and converted to a change in a controlling variable. To ensure the production of a component with especially high dimensional accuracy, a geometric variable is measured at a first measurement site in the area of the drawing bulb for the prediction of the estimate, and the temperature of the drawing bulb be measured and used as a controlled variable.

Abstract: A system for automated production of a fiber optic device includes a chamber regulating an environment and/or atmosphere within for the automated production of the fiber optic device. The system also includes a sealable input port, communicating with the chamber and substantially sealing the environment and the atmosphere of the chamber. The sealable input port receives an optical fiber for insertion therethrough into the chamber. A movable holding stage is included within the chamber, including at least one clamp to be secured to the optical fiber. An energy source is disposed within the chamber, and used to apply energy to the optical fiber. The system also includes a gripping device within the chamber. The gripping device includes a cavity adapted for receiving the optical fiber therethrough and for securing thereto.

Abstract: A furnace body for a glass preform elongating apparatus which makes an elongated body by passing the glass preform through the furnace body and elongating the glass preform while heating the glass preform, the furnace body comprising a furnace core tube shaped like a cylinder through which the glass preform passes and having so adequate length in an axial direction that the elongated body may not bend or distort its form, a heating member disposed at an outer peripheral portion of the furnace core tube, a thermal insulator enveloping the furnace core tube and the heating member from outside in circumferential and axial directions thereof, and a furnace body outer shell holding the thermal insulator therein, wherein a through hole is disposed near the heating member downstream thereof in an advancing direction of the glass preform so as to penetrate through the furnace core tube, thermal insulator, and furnace body outer shell in the direction orthogonal to the furnace core tube.

Abstract: A device for drawing down an optical fiber preform (2) connected at one end to a feed rod (3) having an equal or smaller diameter. A chamber (11) in which the preform is drawn has an upper part (11A) with an opening (12). The opening engages the preform to seal the chamber. An enclosure (5) has a seal (6) at its upper part (5A) for sealing around the feed rod. A lower part (5B) of the enclosure contacts the upper part of the chamber to seal the chamber while the feed rod is passing through the opening.

Abstract: The invention provides an optical fiber producing apparatus having non-contact fiber tension monitoring, comprising: a traveling wave wavelet transformation processor and a time-of-flight fiber tension processor. The traveling wave transformation processor responds to a fiber transverse position processor signal representing information relating to a traveling wave propagating in one direction along a moving fiber and a reflection of the traveling wave propagating back in an opposite direction along the moving fiber, and provides a traveling wave transformation processor signal. The time-of-flight fiber tension processor responds to the traveling wave transformation processor signal, and further responsive to a fiber draw speed signal, and provides a time-of-flight fiber tension processor signal indicative of a fiber tension of the moving fiber using traveling wave time-of-flight analysis.

Abstract: A method and apparatus are provided for drawing a self-aligned core fiber free of surface contamination and inserting the core fiber into a cladding material to make an optical fiber preform. Single or multi-mode optical fibers having high quality core-clad interfaces can be directly drawn from the preforms described herein.

Abstract: An optical fiber preform manufacturing apparatus which continuously monitors the weight of a preform during manufacturing by a load cell without increasing the offset amount of the preform. The preform manufacturing apparatus includes a rotary chuck unit vertically moved by an elevating unit and a rod gripped by the rotary chuck unit and vertically extending downward. At the time of manufacturing a preform, the elevating unit and the rotary chuck unit are driven to rotate and move a starting rod suspended from the lower end of the rod upward. A support plate is fixed to the rotary chuck unit. Three or more load cells are arranged between the support plate and an elevating plate of the elevating unit. The rotary chuck unit is firmly supported by these load cells, so that the rotating shaft is not inclined. A hole is formed in the elevating plate, and the rotary chuck unit extends through the hole with a gap therebetween.

Abstract: An apparatus and process for the production of a composite thread of glass and of organic material wherein continuous filaments of thermoplastic organic material are mixed in the form of a sheet with a bundle or sheet of glass filaments, with the speed of the thermoplastic filaments during their penetration into the bundle or sheet of glass filaments being greater than the speed of drawing of the glass filaments.

Abstract: A method and apparatus are provided for detecting irregular portions of an optical fiber which arise due to microscopic bubbles, bruises, and the like during an optical fiber drawing process. The present invention operates by varying the pulling rate of a pulling capstan based on feeding back measurements of the external diameter of the optical fiber to the pulling capstan. The ratio of a given pulling rate variation to a predetermined time period is then computed. The computed ratio is then compared to a previously specified value.

Abstract: A system for controlling the drawing of a hermetically-coated optical waveguide fiber from a preform is provided in which two measurements of fiber diameter are made and combined into an overall control signal. The first measurement is made on bare fiber in the region of the preform's root using an interference technique. The second measurement is made after the hermetic coating has been applied using a shadow technique. The first measurement provides high speed, high accuracy data needed for process control and defect detection. It is, however, subject to error due to fluctuations in the root with tractor speed. The second measurement reduces the effects of such error on the overall control signal.

Abstract: An apparatus for producing a glass preform by VAD, includes a rotational drive device for rotating soot material, a detection device for detecting vibrations of the soot material, and a control device for controlling rotational speed of the rotational drive device. The control drive device changes the rotational speed of the rotational drive device on the basis of a detection output of the detection device.

Abstract: An apparatus for fabricating an optical fiber coupler having a well-controlled quality and an improved packaged strength is provided. The apparatus includes a holding device holding thereon a quartz tube sleeving therein an optical fiber strand having a spliced portion to be fused, two pulling stages oppositely pulling the fiber strand, a heating device having two torch blowpipes for heating through the quartz tube the spliced portion, a first driving mechanism for oppositely translating the pulling stages, a second driving mechanism for reciprocatingly translating the blowpipes along the quartz tube, and a programmable controller coupled to and for controlling the heating device, the first and the second driving mechanisms. A method for fabricating the optical fiber coupler is also disclosed.