Abstract: In a unit gravity environment, a glass preform is encased in a material to generate an encased glass preform. The material remains solid at the glass preform's crystal melting temperature and is inert with respect to the glass preform. The encased glass preform is placed in a microgravity environment and heated to a temperature above the crystal melting temperature until the glass preform melts and is free of crystals, wherein a crystallite-free glass preform is encased within the material. The crystallite-free glass preform is then cooled in the microgravity environment to generate a solid crystallite-free glass preform encased within the material. While still in the microgravity environment, the material encasing the solid crystallite-free glass preform is removed in the microgravity environment and the solid crystallite-free glass preform is polished. A glass optical fiber is then drawn from the solid crystallite-free glass preform in the microgravity environment.

Abstract: A method of manufacturing an optical fiber of the invention includes: preparing one or more direction changers; drawing the bare optical fiber from an optical fiber preform; providing a coated layer on a periphery of the bare optical fiber; obtaining an optical fiber by curing the coated layer; changing the direction of the bare optical fiber at the position between the bare-optical-fiber formation position and the coated-layer provision position; detecting the position of the bare optical fiber in at least one of the direction changers; and adjusting the introduction flow rate of the fluid into the direction changer based on positional information obtained by the detection.

Abstract: A method of manufacturing an optical fiber includes drawing an optical fiber preform and forming a bare optical fiber, disposing a coating layer formed of a resin on an outer circumference of the bare optical fiber, and curing the coating layer and obtaining an optical fiber. A direction of the bare optical fiber is changed by a direction changer in any position from drawing the optical fiber to disposing the coating layer, and the direction changer includes a guide groove which guides the bare optical fiber.

Abstract: A method of manufacturing an optical fiber including drawing an optical fiber preform and forming a bare optical fiber, disposing a coating layer formed of a resin on an outer circumference of the bare optical fiber, and curing the coating layer and obtaining an optical fiber is provided. A direction of the bare optical fiber is changed by a direction changer in any position from drawing the optical fiber to disposing the coating layer. In a flow rate of a fluid from a blowout port, an average flow rate or a highest flow rate in an inlet wire portion and an outlet wire portion is higher than a lowest flow rate of the fluid in an intermediate portion.

Abstract: An optical fiber fusion splicer includes: a windshield cover that is formed so as to be openable and closable and that includes one or more cover members that cover a heat fusion portion in a closed state; a pair of fiber mounting portions that are provided on left and right sides of the heat fusion portion; a pair of fiber mounting detectors that are provided in the fiber mounting portions and that detect that an optical fiber has been mounted. Also, when both the fiber mounting detectors detect that the optical fibers have been mounted in a state where the cover member is open, an operation to close the cover member is performed, the fusion splice is performed, connection portion inspection is performed, and an operation to open the windshield cover is performed after the connection portion inspection is completed.

Abstract: This optical fiber manufacturing method includes: forming a bare optical fiber by drawing an optical fiber preform; forming an intermediate optical fiber by providing a coating layer, which is formed of resin, on the outer periphery of the bare optical fiber; performing primary curing of the coating layer which forms the intermediate optical fiber; pressing the outer periphery of the intermediate optical fiber; and performing secondary curing of the pressed coating layer of the intermediate optical fiber.

Abstract: Disclosed herein are a graphite crucible for electromagnetic induction-based silicon melting and an apparatus for silicon melting/refining using the same, which performs a melting operation by a combination of indirect melting and direct melting. The crucible is formed of a graphite material and includes a cylindrical body having an open upper part through which a silicon raw material is charged into the crucible, and an outer wall surrounded by an induction coil, wherein a plurality of slits are vertically formed through the outer wall and an inner wall of the crucible such that an electromagnetic force created by an electric current flowing in the induction coil acts toward an inner center of the crucible to prevent a silicon melt from contacting the inner wall of the crucible.

Abstract: A new radiation curable Secondary Coating for optical fibers is described and claimed wherein said composition comprises a Secondary Coating Oligomer Blend, which is mixed with a first diluent monomer; a second diluent monomer; optionally, a third diluent monomer; an antioxidant; a first photoinitiator; a second photoinitiator; and optionally a slip additive or a blend of slip additives; wherein said Secondary Coating Oligomer Blend comprises: ?) an Omega Oligomer; and ?) an Upsilon Oligomer; wherein said Omega Oligomer is synthesized by the reaction of ?1) a hydroxyl-containing (meth)acrylate; ?2) an isocyanate; ?3) a polyether polyol; and ?4) tripropylene glycol; in the presence of ?5) a polymerization inhibitor; and ?6) a catalyst; to yield the Omega Oligomer; wherein said catalyst is selected from the group consisting of dibutyl tin dilaurate; metal carboxylates, including, but not limited to: organobismuth catalysts such as bismuth neodecanoate; zinc neodecanoate; zirconium neodecanoate; zinc 2-ethylh

Abstract: A multi-electrode system includes a fiber holder that holds at least one optical fiber, a plurality of electrodes arranged to generate a heated field to heat the at least one optical fiber, and a vibration mechanism that causes at least one of the electrodes from the plurality of electrodes to vibrate. The electrodes can be disposed in at least a partial vacuum. The system can be used for processing many types of fibers, such processing including, as examples, stripping, splicing, annealing, tapering, and so on. Corresponding fiber processing methods are also provided.

Abstract: A multi-electrode system includes a fiber holder that holds at least one optical fiber, a plurality of electrodes arranged to generate a heated field to heat the at least one optical fiber, and a vibration mechanism that causes at least one of the electrodes from the plurality of electrodes to vibrate. The electrodes can be disposed in at least a partial vacuum. The system can be used for processing many types of fibers, such processing including, as examples, stripping, splicing, annealing, tapering, and so on. Corresponding fiber processing methods are also provided.

Abstract: A wet-on-dry process for coating a glass optical fiber with a Radiation Curable Secondary Coating, comprising (a) operating a glass drawing tower to produce a glass optical fiber; (b) applying a radiation curable primary coating composition onto the surface of the optical fiber; (c) applying radiation to effect curing of said radiation curable primary coating composition; (d) applying a Radiation Curable Secondary Coating to the radiation curable primary coating; and (e) applying radiation to effect curing of said Radiation Curable Secondary Coating.

Abstract: A Radiation Curable Secondary Coating comprising A) a Secondary Coating Oligomer Blend, which is mixed with B) a first diluent; C) a second diluent; D) an antioxidant; E) a first photoinitiator; F) a second photoinitiator; and G) optionally a slip additive or a blend of slip additives; wherein said Secondary Coating Oligomer Blend comprises: ?) an Alpha Oligomer, which is non-urethane; (?) a Beta Oligomer; which is a urethane or non-urethane. ?) a Gamma Oligomer; wherein said Gamma Oligomer is an epoxy diacrylate.

Abstract: Radiation curable coatings for use as a Primary Coating for optical fibers, optical fibers coated with said coatings and methods for the preparation of coated optical fibers. A radiation curable Primary Coating composition comprising: an oligomer; a diluent monomer; a photoinitiator; an antioxidant; and an adhesion promoter; wherein said oligomer is the reaction product of: a hydroxyethyl acrylate; an aromatic isocyanate; an aliphatic isocyanate; a polyol; a catalyst; and an inhibitor, wherein said catalyst is an organo bismuth catalyst; wherein said oligomer has a number average molecular weight of from at least about 4000 g/mol to less than or equal to about 15,000 g/mol; and wherein a cured film of said radiation curable coating composition has a peak tan delta Tg of from about ?25° C. to about ?45° C.; and a modulus of from about 0.50 MPa to about 1.2 MPa.

Abstract: A method for manufacturing an optical fiber includes melting an end of a crystal material and drawing the molten end of the crystal material to form a crystal filament. Conductive paint is coated on two surface sections of the crystal filament to form internal positive and negative electrodes not electrically connected to each other. The crystal filament is placed into a heat resistant tube that is heated until an outer layer of the crystal filament melts and adheres to an inner periphery of the heat resistant tube, with a center of the crystal filament remaining as a solid core. Conductive paint is adhered to two ends of the crystal filament to form external positive and negative electrodes electrically connected to the internal positive and negative electrodes, respectively. The optical fiber thus formed can serve as a photoelectric optical fiber for transmission of current signals.

Abstract: Radiation curable coatings for use as a Primary Coating for optical fibers, optical fibers coated with said coatings and processes to coat the optical fiber are described and claimed. The radiation curable coating is a radiation curable Primary Coating composition comprising: an oligomer; a first diluent monomer; a second diluent monomer, a photoinitiator; an antioxidant; and an adhesion promoter; wherein said oligomer is the reaction product of: a hydroxyethyl acrylate; an aromatic isocyanate; an aliphatic isocyanate; a polyol; a catalyst; and an inhibitor, and wherein said oligomer has a number average molecular weight of from at least about 4000 g/mol to less than or equal to about 15,000 g/mol; wherein a cured film of said radiation curable primary coating composition has a peak tan delta Tg of from about ?25° C. to about ?45° C. and a modulus of from about 0.50 MPa to about 1.2 MPa.

Abstract: The present invention relates to a method for manufacturing a primary preform for optical fibers, using an internal vapor deposition process, wherein a gas flow of doped undoped glass-forming gases is supplied to the interior of a hollow substrate tube having a supply side and a discharge side via the supply side thereof, wherein deposition of glass layers on the interior of the substrate tube is effected as a result of the presence of a reaction zone.

Abstract: A method of creating optical fiber to exhibit predetermined length-dependent characteristics (e.g., chromatic dispersion, polarization mode dispersion, cutoff wavelength, birefringence) includes the steps of: characterizing the fiber's selected characteristic(s) as a function of length; and performing a “treatment” which modifies the refractive index over the given length to adjust the defined parameter to fall within a defined tolerance window. These steps may be repeated one or more times until the measure of the parameter falls with the defined tolerance limits. The treatment process may include, for example, a low energy actinic radiation exposure, anneal, mechanical strain, DC voltage, plasma application, etc. Indeed, if the treatment process is repeated, a different technique may be used to adjust the refractive index (“different” processes include, for example, modifying the strength/time of a UV exposure, temperatures for annealing, etc.).

Abstract: An optical fiber apparatus is suitable to operate under irradiation, more particularly to mitigating the damage of a rare-earth-doped optical fiber element as part of an optical fiber assembly causes by irradiation. The irradiation mitigation attributes to a photo-annealing apparatus including at least a shorter wavelength photo-annealing spectral content, which is relative to that of a pump light source, for effectively photo-annealing the rare-earth-doped fiber element. Photo-annealing by such shorter wavelength light results in a fast and nearly complete recovery of radiation induced attenuation of the rare-earth-doped optical fiber element in the wavelength range from 900 nm to 1700 nm.

Abstract: A method for forming buried ion-exchanged waveguides involves a two-step process. In a first step a waveguide is formed at the surface of a substrate using an ion-exchange technique. After formation of the waveguide, a field-assisted annealing is carried out to move the waveguide away from the surface of the substrate so that it is buried in the substrate. Exemplary field-assisted annealing is carried out at a temperature close to the ion-exchange temperature ±10° C. to optimize results.

Abstract: The present invention relates to a fiber having a core of crystal fiber doped with chromium and a glass cladding. The fiber has a gain bandwidth of more than 300 nm including 1.3 mm to 1.6 mm in optical communication, and can be used as light source, optical amplifier and tunable laser when being applied for optical fiber communication. The present invention also relates to a method of making the fiber. First, a chromium doped crystal fiber is grown by laser-heated pedestal growth (LHPG). Then, the crystal fiber is cladded with a glass cladding by codrawing laser-heated pedestal growth (CDLHPG). Because it is a high temperature manufacture process, the cladding manufactured by this method is denser than that by evaporation technique, and can endure relative high damage threshold power for the pumping light.

Abstract: The invention relates to a Radiation Curable Secondary Coating composition for use on an Optical Fiber. The Radiation Curable Secondary Coating composition is a urethane-free Alpha Oligomer prepared by reaction of the following: (a) an acrylate compound selected from an alcohol-containing acrylate or alcohol-containing methacrylate compound, (b) an anhydride compound, (c) an epoxy-containing compound, (d) optionally an extender compound, and (e) optionally a catalyst. The invention also relates to a coated wire and to a coated optical fiber.

Abstract: A multi-electrode system includes a fiber holder that holds at least one optical fiber, a plurality of electrodes arranged to generate a heated field to heat the at least one optical fiber, and a vibration mechanism that causes at least one of the electrodes from the plurality of electrodes to vibrate. The electrodes can be disposed in at least a partial vacuum. The system can be used for processing many types of fibers, such processing including, as examples, stripping, splicing, annealing, tapering, and so on. Corresponding fiber processing methods are also provided.

Abstract: A multi-electrode system includes a fiber holder that holds at least one optical fiber, a plurality of electrodes arranged to generate a heated field to heat the at least one optical fiber, and a vibration mechanism that causes at least one of the electrodes from the plurality of electrodes to vibrate. The electrodes can be disposed in at least a partial vacuum. The system can be used for processing many types of fibers, such processing including, as examples, stripping, splicing, annealing, tapering, and so on. Corresponding fiber processing methods are also provided.

Abstract: A method for producing an optical fiber that includes a method for producing an optical fiber, said method comprising: (i) drawing a bare optical fiber from a preform along a first pathway at a rate of at least 10 m/sec; (ii) contacting said bare optical fiber with a region of fluid in a fluid bearing and redirecting said bare optical fiber along a second pathway as said bare optical fiber is drawn across said region of fluid cushion; (iii) coating the bare optical fiber; and (iv) irradiating said coated fiber in at least one irradiation zone to at least partially cure said coating, while subjecting the optical fiber to UV light.

Abstract: Apparatus for forming fibers or flakes of material comprises means (1) for producing a heated stream of molten material (9), means for feeding the stream in a substantially vertically downward direction and means (7) for receiving the downwardly directed stream and for forming fibers or flakes therefrom. The apparatus includes means (11, 13, 15, 17) for effecting a change in the temperature of the stream subsequent to the production thereof whereby fibers or flakes of a desired thickness are obtained. Instead of, or in addition to, the temperature changing means, there may be provided means for controlling the mass or volume flow of the stream. The invention also provides methods corresponding to the apparatus.

Abstract: Disclosed is a method of heat treating quartz glass deposition tubes at between 900° C. and 1200° C. for at least 115 hours. The resulting deposition tubes are useful in forming optical preforms that can yield optical fibers having reduced added loss.

Abstract: The present invention relates to an apparatus for carrying out a PCVD deposition process, wherein one or more doped or undoped layers are coated onto the interior of a glass substrate tube, which apparatus comprises an applicator having an inner and an outer wall and a microwave guide which opens into the applicator, which applicator extends around a cylindrical axis and which is provided with a passage adjacent to the inner wall, through which the microwaves can exit, over which cylindrical axis the substrate tube can be positioned, and wherein at least one choke of annular shape having a length l and a width w is centred around the cylindrical axis within the applicator.

Abstract: An optical fiber sensing cable is disclosed. The optical fiber sensing cable comprises a fiber with a core having an index of refraction n1, and a circumferential surface of the fiber including a nanoporous cladding having an index of refraction index n2. The methods of preparing the fiber sensor cable, including forming the nanoporous cladding and the sensor systems incorporating the optical fiber sensing cable of this invention are also disclosed.

Abstract: The present invention relates to a system for manufacturing fibres comprising a melting furnace, a crucible within said furnace comprising at least one orifice (6) and at least one induction coil (4) for heating the melting furnace and the crucible. In a typical system according to the invention, the crucible comprises at least a first part (1) made of graphite and comprising said at least one orifice (6). The invention also relates to the use of the system as well as to a method for manufacturing fibres and to said fibres.

Abstract: The invention relates to a method for producing an infrared transmitting fiber (50) comprising the steps of providing a preform (20) of the infrared transmitting fiber (50) to be produced, said preform (20) comprising a receptacle, which is the precursor of the fiber's cladding, and a solid solution provided inside said receptacle, said solid solution being the precursor of the fiber's core; heating the fiber's preform (20) up to a temperature in which the receptacle softens and the solid solution melts; collecting the flow generated by the softened receptacle; drawing the fiber (50) from the collected flow.

Abstract: A multi-electrode system comprises a fiber support configured to hold at least one optical fiber and a set of electrodes disposed about the at least one optical fiber and configured to generate arcs between adjacent electrodes to generate a substantially uniform heated field to a circumferential outer surface of the at least one optical fiber. The electrodes can be disposed in at least a partial vacuum.

Abstract: Provided is an apparatus for manufacturing an optical fiber Bragg grating.

Abstract: Adverse hydrogen aging limitations in multiply-doped optical fibers are overcome by passivating these optical fibers using a deuterium passivation process. This treatment essentially pre-reacts the glass with deuterium so that the most active glass sites are no longer available to react with hydrogen in service. Optical fibers of main interest are doped with mixtures of germanium and phosphorus. Optimum passivating process conditions are described.

Abstract: A method for producing an optical fiber that includes a method for producing an optical fiber, said method comprising: (i) drawing a bare optical fiber from a preform along a first pathway at a rate of at least 10 m/sec; (ii) contacting said bare optical fiber with a region of fluid in a fluid bearing and redirecting said bare optical fiber along a second pathway as said bare optical fiber is drawn across said region of fluid cushion; (iii) coating the bare optical fiber; and (iv) irradiating said coated fiber in at least one irradiation zone to at least partially cure said coating, while subjecting the optical fiber to UV light.

Abstract: An expeditious method for introducing geometric perturbations into lightguide during fabrication offers a perturbation stream of amplitude and periodicity—constant or varying—to satisfy a variety of needs.

Abstract: Disclosed is a method of heat treating quartz glass deposition tubes at between 900° C. and 1200° C. for at least 115 hours. The resulting deposition tubes are useful in forming optical preforms that can yield optical fibers having reduced added loss.

Abstract: In some embodiments of the present invention, an electrical field is applied across a waveguide substrate so as to induce ion exchange process that affects the cross section of the waveguide. Shaped electrical field may, according to the invention, may control the size and shape of the waveguide along it.

Abstract: Epoxy-functional polysiloxanes containing epoxy groups and hydrocarbyl groups free of aliphatic unsaturation, a silicone composition containing a polysiloxane selected from the aforementioned epoxy-functional polysiloxanes, a cured polysiloxane prepared by exposing the silicone composition to ultraviolet radiation, a coated optical fiber containing a cured polysiloxane, and a method of preparing a coated optical fiber.

Abstract: This invention provides an inexpensive and rapid method for fabricating a high-anisotropic-etch ratio, shaped glass structures using a novel photosensitive glass composition. Structures of the photosensitive glass may include micro-channels, micro-optics, microposts, or arrays of hollow micro-needles. Furthermore, such shaped glass structures can be used to form a negative mold for casting the shape in other materials.

Abstract: The invention relates to a Radiation Curable Secondary Coating composition for use on an Optical Fiber. The Radiation Curable Secondary Coating composition is a urethane-free Alpha Oligomer prepared by reaction of the following: (a) an acrylate compound selected from an alcohol-containing acrylate or alcohol-containing methacrylate compound, (b) an anhydride compound, (c) an epoxy-containing compound, (d) optionally an extender compound, and (e) optionally a catalyst. The invention also relates to a coated wire and to a coated optical fiber.

Abstract: A Radiation Curable Secondary Coating comprising A) a Secondary Coating Oligomer Blend, which is mixed with B) a first diluent; C) a second diluent; D) an antioxidant; E) a first photoinitiator; F) a second photoinitiator; and G) optionally a slip additive or a blend of slip additives; wherein said Secondary Coating Oligomer Blend comprises: ?) an Alpha Oligomer, which is non-urethane; ?) a Beta Oligomer; which is a urethane or non-urethane. ?) a Gamma Oligomer; wherein said Gamma Oligomer is an epoxy diacrylate.

Abstract: Radiation curable coatings for use as a Primary Coating for optical fibers, optical fibers coated with said coatings and processes to coat the optical fiber are described and claimed. The radiation curable coating is a radiation curable Primary Coating composition comprising: an oligomer; a first diluent monomer; a second diluent monomer, a photoinitiator; an antioxidant; and an adhesion promoter; wherein said oligomer is the reaction product of: a hydroxyethyl acrylate; an aromatic isocyanate; an aliphatic isocyanate; a polyol; a catalyst; and an inhibitor, and wherein said oligomer has a number average molecular weight of from at least about 4000 g/mol to less than or equal to about 15,000 g/mol; wherein a cured film of said radiation curable primary coating composition has a peak tan delta Tg of from about ?25° C. to about ?45° C. and a modulus of from about 0.50 MPa to about 1.2 MPa.

Abstract: A new radiation curable Secondary Coating for optical fibers is described and claimed wherein said composition comprises a Secondary Coating Oligomer Blend, which is mixed with a first diluent monomer; a second diluent monomer; optionally, a third diluent monomer; an antioxidant; a first photoinitiator; a second photoinitiator; and optionally a slip additive or a blend of slip additives; wherein said Secondary Coating Oligomer Blend comprises: ?) an Omega Oligomer; and ?) an Upsilon Oligomer; wherein said Omega Oligomer is synthesized by the reaction of ?1) a hydroxyl-containing (meth)acrylate; ?2) an isocyanate; ?3) a polyether polyol; and ?4) tripropylene glycol; in the presence of ?5) a polymerization inhibitor; and ?6) a catalyst; to yield the Omega Oligomer; wherein said catalyst is selected from the group consisting of dibutyl tin dilaurate; metal carboxylates, including, but not limited to: organobismuth catalysts such as bismuth neodecanoate; zinc neodecanoate; zirconium neodecanoate; zinc 2-ethylh

Abstract: Radiation curable coatings for use as a Primary Coating for optical fibers, optical fibers coated with said coatings and processes for coating optical fibers.

Abstract: Radiation curable coatings for use as a Primary Coating for optical fibers, optical fibers coated with said coatings and methods for the preparation of coated optical fibers. A radiation curable Primary Coating composition comprising: an oligomer; a diluent monomer; a photoinitiator; an antioxidant; and an adhesion promoter; wherein said oligomer is the reaction product of: a hydroxyethyl acrylate; an aromatic isocyanate; an aliphatic isocyanate; a polyol; a catalyst; and an inhibitor, wherein said catalyst is an organo bismuth catalyst; wherein said oligomer has a number average molecular weight of from at least about 4000 g/mol to less than or equal to about 15,000 g/mol; and wherein a cured film of said radiation curable coating composition has a peak tan delta Tg of from about ?25° C. to about ?45° C.; and a modulus of from about 0.50 MPa to about 1.2 MPa.

Abstract: Radiation curable coatings for use as a Primary Coating for optical fibers, optical fibers coated with said coatings and methods for the preparation of coated optical fibers. The radiation curable coating comprises at least one (meth)acrylate functional oligomer and a photoinitiator, wherein the urethane-(meth)acrylate oligomer CA/CR comprises (meth)acrylate groups, at least one polyol backbone and urethane groups, wherein about 15% or more of the urethane groups are derived from one or both of 2,4- and 2,6-toluene diisocyanate, wherein at least 15% of the urethane groups are derived from a cyclic or branched aliphatic isocyanate, and wherein said (meth)acrylate functional oligomer has a number average molecular weight of from at least about 4000 g/mol to less than or equal to about 15,000 g/mol; and wherein a cured film of the radiation curable Primary Coating composition has a modulus of less than or equal to about 1.2 MPa.

Abstract: The present invention provides an ultra-thin high-precision glass optic and method of manufacturing the same. The optic has an axial thickness that is less than 1,000 microns. A pattern and/or coating is disposed on a surface of the optic to provide attenuation of light in an optical system. In an embodiment, the optic is manufactured by disposing a pattern on a surface of a reticle. The pattern is covered with a first protective coating to protect the pattern. Individual optics are cut from the reticle so that each optic includes a portion of the pattern. The optic is thinned by removing material until it has an axial thickness of less than 1,000 microns. The optic is cleaned after thinning and covered with an anti-reflective coating.

Abstract: In a device (5) for the manufacture of a quartz glass crucible (2), one section (14, 15) of a wall (13) of the rotating quartz glass crucible (2) is heated at one time by means of at least two electrode arrangements (7, 8) distributed uniformly at the circumference of the quartz glass crucible (2) and generating a first and another electric arc. By providing several electrode arrangements (7, 8), the cooling-down phase of the sections (14, 15) until their reaching the subsequent heating zone (11, 12) can be shortened, and thus an undesirable high temperature difference of the wall (13) can be avoided. Moreover, the required thermal output of each individual electrode arrangement (7, 8) can be reduced, so that evaporation phenomena and connected bubble formation can be reduced. In addition to the higher quality that can be reached in this way, the duration of the manufacturing process is reduced.

Abstract: A method is disclosed for the manufacture of optical fiber preforms using plasma enhanced chemical vapor deposition (PECVD). The invention consists of a cylindrical reactor in which material such as flourine-doped silica glass is deposited on a cylindrical silica rod. A furnace for regulating reactor temperature encases the reactor. A microwave generator coupled with a resonator and an H10 waveguide delivers microwave energy to the reactor, producing simultaneously symmetrical excitations in the E010 mode and a plasma surface wave in E01 mode located at the surface of the rod. A microwave plasma is scanned along the length of the rod through a slit in the reactor to deposit a homogeneous film of a desired thickness. The benefits of the present invention over the prior art include increased absorption of delivered power, and the ability to uniformly deposit films such as flourine-doped silica on rods with diameters of up to 30–35 mm and thus produce optical fiber preforms with diameters greater than 40 mm.

Abstract: An optical fiber is prepared by applying a liquid electron beam-curable resin composition to a bare optical fiber or a coated optical fiber having a primary or secondary coating on a bare optical fiber, irradiating electron beams to the resin composition on the optical fiber for curing while the optical fiber passes a zone under substantially atmospheric pressure, and providing a magnetic field and optionally an electric field in the zone for thereby improving the efficiency of electron irradiation. The method can comply with the increased drawing speed of the bare optical fiber and does not detract from the transmission properties of the optical fiber.