Abstract:
Die Erfindung betrifft ein Verfahren zur Herstellung einer Glasfaser durch ein an einer Preform ausgeführtes Langziehen in einem Ziehofen, wobei eine Abkühlung der Glasfaser in mindestens drei zeitlichen Phasen erfolgt. Bei diesen ist die Glasfaser oberhalb eines Kristallisationstemperatur-Bereiches einer ersten zeitlichen Abkühlrate, innerhalb des Kristallisationstemperatur-Bereiches einer im Vergleich zur ersten Abkühlrate größeren zweiten zeitlichen Abkühlrate und unterhalb des Kristallisationstemperatur-Bereiches einer im Vergleich zur zweiten Abkühlrate geringeren dritten Abkühlrate ausgesetzt.
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:
A cooler of an optical fiber draw tower. The cooler situated below a melting furnace for melting a preform for an optical fiber, for cooling the optical fiber drawn from the preform melted in the melting furnace, includes at least one heat exchanger installed with a predetermined length surrounding the optical fiber drawn from the melting furnace, for cooling the drawn optical fiber. The heat exchanger is formed of a thermo-electric cooler (TEC) for taking electrical energy through one heat absorbing surface to emit heat to the other heat emitting surface and has a tubular shape in which the heat absorbing surface of the TEC surrounds the optical fiber drawn from the melting furnace along the drawing direction by a predetermined length, and the drawn optical fiber is cooled as it passes through the tubular TEC. Also, the cooler further includes an auxiliary cooler attached to the heat emitting surface of the TEC, for cooling the emitted heat. Therefore, the cooler can enhance the cooling effect, so that the drawing of the optical fiber can be sped up without increasing the height of the optical fiber draw tower.
Abstract:
A single mode optical fiber having a core made from silica and less than or equal to about 6.5 weight% germania and having a maximum relative refractive index Δ 1ΜΑΧ . The optical fiber also has an inner cladding surrounding the core and having a minimum relative refractive index Δ 2ΜΙΝ · A difference between a softening point of the core and a softening point of the inner cladding is less than or equal to about 20 °C, and Δ 1ΜΑΧ > Δ 2ΜΑΧ . The single mode optical fiber may also have an outer cladding surrounding the inner cladding made from silica or SiON. The outer cladding has a maximum relative refractive index Δ 3ΜΑΧ , and Δ 3ΜΑΧ > Δ 2ΜΙΝ . A method for manufacturing an optical fiber includes providing a preform to a first furnace, the preform, drawing the optical fiber from the preform, and cooling the drawn optical fiber in a second furnace.
Abstract:
A method of controlling the temperature of an optical fiber is provided that includes the steps of: providing an energy transfer member configured to accept or provide thermal energy, the energy transfer member defines an energy transfer surface; passing an optical fiber proximate the energy transfer member such that a gap is defined between the optical fiber and the energy transfer surface; and transferring thermal energy between the optical fiber and the energy transfer member via conduction across the gap.
Abstract:
A method of making optical fibers that includes controlled cooling to produce fibers having a low concentration of non-bridging oxygen defects and low sensitivity to hydrogen. The method may include heating a fiber preform above its softening point, drawing a fiber from the heated preform and passing the fiber through two treatment stages. The fiber may enter the first treatment stage at a temperature between 1500°C and 1700°C, may exit the first treatment stage at a temperature between 1200°C and 1400°C, and may experience a cooling rate less than 5000°C/s in the first treatment stage. The fiber may enter the second treatment stage downstream from the first treatment stage at a temperature between 1200°C and 1400°C, may exit the second treatment stage at a temperature between 1000°C and 1150°C, and may experience a cooling rate between 5000 o?C/s and 12,000°C/s in the second treatment stage. The method may also include redirecting the fiber with a fluid bearing device or an air-turn device.