摘要:
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. A measuring device to which a measurement site in the softened area of the blank is assigned is preferably provided to detect the geometric variable of the component.
摘要:
An optical fiber preform includes: a columnar portion having an approximately constant radius of r; and a taper portion located adjacent to the columnar portion in a lengthwise direction and having a radius decreasing along the lengthwise direction. The taper portion includes: a first taper portion including a portion having a radius varying between 0.9r and 0.6r; and a second taper portion including a portion having a radius varying between 0.4r and 0.15r. A diameter of the first taper portion in the portion having the radius varying between 0.9r and 0.6r decreases so as to form a maximum angle θ1 between 40 degrees and 60 degrees with respect to the columnar portion, a diameter of the second taper portion in the portion having the radius varying between 0.4r and 0.15r decreases so as to form an average angle θ2 between 5 degrees and 30 degrees with respect to a central axis in the lengthwise direction, and a volume of the taper portion is smaller than or equal to 45% of a volume of a column having a same outer diameter as a maximum outer diameter of the taper portion and having a same length as the taper portion.
摘要:
An optical fiber preform that is used in a method in which a core rod that forms a core is inserted into a quartz tube that forms a cladding, and at the same time as they are fiber-drawn, the quartz tube and the core rod are formed into a single body, includes: a tapered portion that is formed by grinding an outer circumferential portion of a distal end portion of the quartz tube into a tapered shape; and a conical portion that is formed by welding a dummy tube that has substantially the same outer diameter as the outer diameter of a distal end portion of the tapered portion to the distal end portion of the tapered portion, and by applying heat to the dummy tube and stretching out the dummy tube, where the core rod is inserted inside the quartz tube.
摘要:
An optical fiber preform that is used in a method in which a core rod that forms a core is inserted into a quartz tube that forms a cladding, and at the same time as they are fiber-drawn, the quartz tube and the core rod are formed into a single body, includes: a tapered portion that is formed by grinding an outer circumferential portion of a distal end portion of the quartz tube into a tapered shape; and a conical portion that is formed by welding a dummy tube that has substantially the same outer diameter as the outer diameter of a distal end portion of the tapered portion to the distal end portion of the tapered portion, and by applying heat to the dummy tube and stretching out the dummy tube, where the core rod is inserted inside the quartz tube.
摘要:
Drawing methods and drawing furnaces for drawing an optical fiber with small non-circularity by simple drawing system are provided. An optical fiber preform is received into a muffle tube and heated by a primary heater placed to surround the muffle tube. The optical fiber preform is heated such that a starting position of a meniscus portion is higher in its position than the top of the primary heater, wherein the meniscus portion is created at the bottom portion of the optical fiber preform.
摘要:
A method of manufacturing a single mode optical fiber formed of a silica-based glass and including a glass part having a central core and a cladding region. The method including heating an optical fiber preform in a heating furnace including a first heater to melt the optical fiber preform, and fiber drawing an optical fiber from the molten optical fiber preform. The method further comprises continuously cooling the drawn optical fiber starting with a meniscus portion in which diameter is decreased from 90% of the preform diameter to 5% of the preform diameter to a portion where the drawn optical fiber has a temperature of 1,200° C. at a cooling rate of 1,000 to 3,000° C. /sec.
摘要:
In a single mode optical fiber formed of a silica-based glass and including a glass part having a central core and a cladding region, the density of non bridging oxygen hole center in the glass part is not higher than 1.0×1014 spins/g in terms of the spin density measured by an electron spin resonance method.
摘要:
In a single mode optical fiber formed of a silica-based glass and including a glass part having a central core and a cladding region, the density of non bridging oxygen hole center in the glass part is not higher than 1.0×1014 spins/g in terms of the spin density measured by an electron spin resonance method.
摘要:
In the manufacture of high quality optical fibre for telecommunications, a preform (1) is advanced towards a furnace (9) until a tip detector (5) automatically stops the preform (1) at a predetermined position (11) in front of the furnace to provide a reference datum for a second mode of operation in which the computer (12) can be initiated manually (12B) to advance (4) the preform (1) by a predetermined amount into the furnace to commence drawing the optical fibre. Preferably the tip detector is a paddle (6) pivotally mounted (7) and operates an optical sensor (8).