Abstract: A method for manufacturing an optical preform via an internal vapor deposition process, wherein during the inside deposition process the velocity of the reaction zone is set so that the velocity of the reaction zone over the length of the supply side-to-discharge side is higher than the velocity of the reaction zone over the length of the discharge side-to-supply side.

Abstract: A method for manufacturing a primary preform for an optical fiber wherein conditions are created in the reaction zone such that one or more glass layer packages made up of at least two separate glass layers are deposited on the interior of the substrate tube. A method for manufacturing a final preform as well as primary preforms, final preforms and optical fibers obtained therewith.

Abstract: Method and plasma treatment apparatus for treatment of a substrate surface (1) using an atmospheric pressure plasma. An atmospheric pressure plasma is provided in a treatment space (5) between a first electrode (2) and a second electrode (3). Furthermore, a substrate (1) and a mask web (7) in contact with the substrate (1) are provided. A plasma generating power is applied to the first and second electrode (2, 3) for treatment of surface areas of the substrate (1) exposed by the mask web (7), in which the substrate (1) and mask web (7) are moved synchronously through the treatment space (5).

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 and apparatus for treatment of a substrate surface using an atmospheric pressure plasma is disclosed. The method comprises providing an atmospheric pressure plasma in a treatment space between a first electrode and a second electrode, providing a substrate in contact with the first electrode in the treatment space, and applying a plasma generating power to the first and second electrodes. The first electrode has a predefined structure of insulating areas and conductive areas for plasma treatment of surface areas of the substrate corresponding to the areas in contact with the conductive areas of the first electrode.

Abstract: A method for manufacturing a primary preform for optical fibers using an internal vapor deposition process, including the steps of: i) providing a hollow glass substrate tube having a supply side and a discharge side, ii) surrounding at least part of the hollow glass substrate tube by a furnace, iii) supplying a gas flow, doped or undoped, of glass-forming gases to the interior of the hollow glass substrate tube via the supply side thereof, iv) creating a reaction zone in which conditions such that deposition of glass will take place on the interior of the hollow glass tube are created, and v) moving the reaction zone back and forth in longitudinal direction over the hollow glass substrate tube between a reversal point located near the supply side and a reversal point located near the discharge side of the hollow glass substrate tube.

Abstract: A method for manufacturing a primary preform for optical fibers using an internal vapor deposition process, including the steps of: i) providing a hollow glass substrate tube having a supply side and a discharge side, ii) surrounding at least part of the hollow glass substrate tube by a furnace, iii) supplying doped or undoped glass-forming gases to the interior of the hollow glass substrate tube via the supply side thereof, iv) creating a reaction zone in which conditions such that deposition of glass will take place on the interior of the hollow glass tube are created, and v) moving the reaction zone back and forth along the length of the hollow glass substrate tube between a reversal point located near the supply side and a reversal point located near the discharge side of the hollow glass substrate tube, wherein, during at least part of step v), the gas flow comprises a first concentration of fluorine-containing compound when the reaction zone is moving in the direction of the discharge side.

Abstract: A device for contracting a hollow substrate tube made of quartz glass into an optical perform including a heat source movable relative to the longitudinal direction of the substrate tube and an insert tube positioned in the interior of the substrate tube, at one end thereof, provided with a central opening through which a gas is passed and supplied to the interior of the substrate tube.

Abstract: Disclosed are methods for deposition of a chemical compound or element using an atmospheric pressure glow discharge plasma in a treatment space comprising two electrodes connected to a power supply for providing electrical power during an on-time (ton). The treatment space is filled with a gas composition of an active and an inert gas mixture, including a precursor of the chemical compound or element to be deposited. Dust formation is prevented by using Nitrogen in the gas composition, applying short pulses and using a predetermined residence time of the gas composition in the treatment space. Best results are obtained when using a stabilized plasma.

Abstract: A method for manufacturing an optical preform via an internal vapour deposition process, wherein during the inside deposition process the velocity of the reaction zone is set so that the velocity of the reaction zone over the length of the supply side-to-discharge side is higher than the velocity of the reaction zone over the length of the discharge side-to-supply side.

Abstract: The present invention relates to a method for manufacturing a primary preform for optical fibres, using an internal vapour 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 for manufacturing a primary preform for optical fibres using an internal vapour deposition process, including the steps of: i) providing a hollow glass substrate tube having a supply side and a discharge side, ii) surrounding at least part of the hollow glass substrate tube by a furnace, iii) supplying doped or undoped glass-forming gases to the interior of the hollow glass substrate tube via the supply side thereof, iv) creating a reaction zone in which conditions such that deposition of glass will take place on the interior of the hollow glass tube are created, and v) moving the reaction zone back and forth along the length of the hollow glass substrate tube between a reversal point located near the supply side and a reversal point located near the discharge side of the hollow glass substrate tube, wherein, during at least part of step v), the gas flow comprises a first concentration of fluorine-containing compound when the reaction zone is moving in the direction of the discharge side.

Abstract: A method for manufacturing a primary preform for optical fibres using an internal vapour deposition process, including the steps of: i) providing a hollow glass substrate tube having a supply side and a discharge side, ii) surrounding at least part of the hollow glass substrate tube by a furnace, iii) supplying a gas flow, doped or undoped, of glass-forming gases to the interior of the hollow glass substrate tube via the supply side thereof, iv) creating a reaction zone in which conditions such that deposition of glass will take place on the interior of the hollow glass tube are created, and v) moving the reaction zone back and forth in longitudinal direction over the hollow glass substrate tube between a reversal point located near the supply side and a reversal point located near the discharge side of the hollow glass substrate tube.

Abstract: The present invention relates to a method of and arrangement for removing contaminants from a surface of a substrate by subjecting said substrate surface to an atmospheric pressure glow plasma. Said plasma is generated in a discharge space comprising a plurality of electrodes, by applying an alternating plasma energizing voltage to said electrodes causing a plasma current and a displacement current. Said plasma is stabilised by controlling said displacement current during plasma generation such that modification of properties of said substrate surface is prevented.

Abstract: Method and apparatus for treatment of a substrate surface (1) using an atmospheric pressure plasma. The method comprises providing an atmospheric pressure plasma in a treatment space (5) between a first electrode (2) and a second electrode (3), providing a substrate (1) in contact with the first electrode (2) in the treatment space (5), and applying a plasma generating power to the first and second electrode (2, 3). The first electrode (2) has a predefined structure of insulating areas (7) and conductive areas (8) for plasma treatment of surface areas of the substrate (1) corresponding to the areas in contact with the conductive areas (8) of the first electrode (2).

Abstract: Method and plasma treatment apparatus for treatment of a substrate surface (1) using an atmospheric pressure plasma. An atmospheric pressure plasma is provided in a treatment space (5) between a first electrode (2) and a second electrode (3). Furthermore, a substrate (1) and a mask web (7) in contact with the substrate (1) are provided. A plasma generating power is applied to the first and second electrode (2, 3) for treatment of surface areas of the substrate (1) exposed by the mask web (7), in which the substrate (1) and mask web (7) are moved synchronously through the treatment space (5).

Abstract: Method and apparatus for generating and sustaining a glow discharge plasma in a plasma discharge space comprising at least two spaced electrodes. The method and apparatus are arranged for performing the steps of introducing in the discharge space a gas or gas mixture under atmospheric pressure conditions, energizing the electrodes by applying an AC energizing voltage (Va) to the electrodes, and controlling the energizing voltage (Va) such that at plasma generation a sharp relative decrease of displacement current is provided.

Abstract: Method and plasma generating apparatus for generating an atmospheric pressure glow discharge plasma in a treatment space (5) filled with a gas composition. Two electrodes (2, 3) are connected to a power supply (4) for providing electrical power during an on-time (ton). The power supply (4) is arranged to provide a periodic signal with an on-time (ton) which is shorter than a predetermined time period, the predetermined time period corresponding substantially to the time necessary for a dust coagulation center from the gas composition to become a cluster in the treatment space (5). This method and apparatus may be used for depositing a layer of material on a substrate (6) in the treatment space (5).

Abstract: Method and apparatus for deposition of a chemical compound or element using an atmospheric pressure glow discharge plasma in a treatment space (5) comprising two electrodes (2, 3) connected to a power supply (4) for providing electrical power during an on-time (ton), the treatment space is filled with a gas composition of an active and an inert gas mixture, including a precursor of the chemical compound or element to be deposited. Dust formation is prevented by using Nitrogen in the gas composition, applying short pulses and using a predetermined residence time of the gas composition in the treatment space. Best results are obtained when using a stabilized plasma.

Abstract: The present invention provides an arrangement and method for generating a uniform and stable plasma. The arrangement comprises a discharge space (7) between at least a pair of electrodes (1, 2), which electrodes (1, 2) are arranged for providing an electric field and for generating a plasma in the electric field. At least one of the electrodes (1) has a boundary surface (6) with the discharge space (7). The boundary surface is comprised of one or more alternately arranged conductive (4) and insulating regions (5). The invention further relates to an electrode (1) for use in the arrangement described. The invention may, for example, be used in dielectric barrier discharge configurations, or in arrangements for generating plasmas at atmospheric pressures, or for generating plasmas at low temperatures, such as generating atmospheric pressure glow plasmas (APG) for material processing or surface (3) treatment purposes.