摘要:
Stress exerted on an inner or outer circumferential side of a glass tube 6 is controlled when a glass material 3 is heated and softened by a heating element 41 provided around the glass material 3 and a piercing plug 31 is relatively pressed into a softened region of the glass material 3 to thereby form the glass material 3 into the glass tube 6 gradually. For example, the control of the stress can be carried out by controlling an internal or external pressure of the glass tube 6. As a result, the deformation of the glass tube 6 just after piercing is prevented so that the glass tube 6 can be obtained with high quality. It is also possible to solve the problem that cracks may occur easily at the time of reheating because of residual stress distribution after cooling.
摘要:
A molding die 1 is constituted by an upper die 1a and a lower die 1b which are made of a material transparent to an ultraviolet light, and has a cavity 3 constituted by grooves 2c, 2d, whereas a resin injection gate 4 and a resin exit gate 7 are provided so as to communicate with the cavity 3. A junction of an optical fiber 10 is inserted into the cavity 3. A UV-curable resin is injected into the cavity 3 surrounding an exposing portion of the glass optical fiber 11 from the resin injection gate 4 positioned at one of coating ends of the optical fiber 10, whereas a part thereof is discharged from the resin exit gate 7 positioned at the other coating end. The ultraviolet light is emitted through the lower die 1b so as to cure the resin, thereby forming a reinforcement resin coating. As a consequence, bubbles can be prevented from occurring due to the residual air within the reinforcement resin coating in the junction of the optical fiber 10.
摘要:
An object of the present invention is to provide a method of highly purifying a glass body, which enables high purification of the glass body while decreasing deformation of the glass body at a high degree, to provide a highly purified glass body, and to provide a method and an apparatus for manufacturing a glass tube, which can obtain a highly purified glass tube. A method of highly purifying a glass body according to the present invention is to apply a voltage between electrodes 1 and 2, which make contact with the glass pipe 11, in a nearly radial direction of the glass pipe 11 while heating the glass pipe 11 to a temperature within a range less than 1300° C. Further, a method of manufacturing a glass tube according to the invention is to generate a voltage gradient in a radial direction of a glass tube 106 by applying voltages to the inner circumferential side and the outer circumferential side of the glass tube 106 when a glass rod 103 is gradually formed into the glass tube 106 by heating the glass rod 103 to soften the glass rod 103 and by bringing a boring jig 130 into contact with a softened portion of the glass rod 103.
摘要:
In a heating furnace which holds at least one end of a glass rod with a holding portion and elongates the glass rod by softening the glass rod successively from the other end portion thereof with heating while applying a tensile force thereto, the heating furnace comprises a tubular portion through which the glass rod to be elongated is inserted such as to be longitudinally movable; heater, positioned within the tubular portion such as to circumferentially surround the glass rod, for heating the glass rod; a moving portion through which one end of the glass rod is inserted; bellows the ends of which are respectively secured to the moving portion and the tubular portion and which is longitudinally expandable and contractible and composed of at least a double cylinder surrounding the part of the glass rod such as to block an outside air from flowing into the heating furnace; and gas supply line for supplying, for purging, an inert gas into a space within the tubular portion and the inner bellows as well as the space between inner and outer bellows.
摘要:
A method for handling a fusion-spliced optical fiber and a transferring jig for transporting the optical fiber are provided. The jig is capable of holding the fusion-spliced optical fiber in a state in which a given tension is applied at the spliced portion, and stopping the application of such tension if needed. The jig is easy to transport and set to each of separate processing processes. In the method, a fusion-spliced optical fiber is clamped at coated portions thereof on both sides of the fusion-spliced portion by a pair of clamps of the jig and transported by the jig holding the optical fiber in a state wherein a given tension is applied thereto through the clamps.
摘要:
An object is to provide an optical fiber fusion splicing method in which splice loss can be reduced, and also to provide an arc-heating unit used for heating the fusion spliced part of an optical fiber. The method comprises a process of fusion-splicing together the end faces of two optical fibers and a process of continuously heating the fusion spliced part by arc while moving one pair of electrodes provided opposite to each other across the fusion spliced part. The arc heating process is performed with the operation for decreasing arc temperature. The operation for decreasing arc temperature may be achieved by flowing a gas having a molecular weight greater than the average molecular weight of air into a gas atmosphere in which arc heating is performed, or by adding a modulation to an electric discharge current such that the maximum value becomes equal to or more than an electric current for starting arc discharge and the minimum value becomes more than zero and less than the electric current for starting arc discharge.
摘要:
The present invention provides a method for manufacturing an optical fiber coupler in which an optical fiber is elongated and heated by using a heating source under a constant tension. The heat source is controlled based on the ratio of a target elongating speed and an actual elongating speed of the optical fiber.
摘要:
Provide are safe equipment and method, in which gas leakage through junction part between a furnace muffle tube and a lid can be restrained, for manufacturing a high quality glass preform. The equipment for manufacturing a glass preform comprises (1) a furnace muffle tube in which a soot glass deposit body is placed, (2) a lid for sealing up an inlet-outlet opening of the furnace muffle tube, and (3) a heater for heating the soot glass deposit body. The method of producing a soot glass deposit body comprises steps of (1) placing a soot glass deposit body into a furnace muffle tube, (2) sealing up the inlet-outlet opening of the furnace muffle tube with a lid, (3) heating the soot glass deposit body so as to vitrify it into a transparent glass body. In these equipment and the method, the surface roughness in the respective junction surfaces of the furnace muffle tube and the lid is 1.0 μm or less, the flatness degree in the respective junction surfaces of the furnace muffle tube and the lid is 30 μm or less, and the load on the junction surface is equal to or more than 98 N.
摘要:
A method of fusion-splicing optical fibers having different mode field diameters or small mode field diameters is provided, which method is advantageous in that the splicing loss is smaller. The method comprises a fusion splicing process in which fusion splicing is performed by butting end faces of two optical fibers together and a heat treatment process in which the fusion spliced part of the optical fibers and the vicinity thereof are heated. The heat treatment process is performed by moving an arc heating unit in a direction other than the Y-axis direction (a direction perpendicular to the Z-axis direction and the opposing direction of arc electrodes) and Z-axis direction (the axial direction of the optical fiber), via the fusion spliced part in a Y-Z plane formed by the Y-axis direction and Z-axis direction.
摘要:
In a method of elongating a glass preform comprising the steps of holding both ends of the glass preform 1a with a first holding section 2 and a second holding section 3, respectively; moving the first holding section 2 and the second holding section 3 in a longitudinal direction of the glass preform 1a with the moving speed of the first holding section 2 faster than that of the second holding section 3 and, at the same time, heating and softening the glass preform 1a by a heating section 4 successively; and elongating the glass preform 1a by a tensile force applied thereto, so as to form an elongated body 1c; an electric furnace is employed in the heating section 4; and said method further comprising the steps of setting a reference value R1 with respect to an outside diameter at a specific position 1d in a tapered region 1b in the glass preform 1a in the process of elongating; acquiring an actually measured value R2 at the specific position 1d; and controlling the moving speed of the first holding section 2 and/or second holding section 3 according to a value (R2/R1) obtained from the reference value R1 and actually measured value R2.