KR101426158B1 - Apparatus for fabricating optical fiber preform - Google Patents

Apparatus for fabricating optical fiber preform Download PDF

Info

Publication number
KR101426158B1
KR101426158B1 KR1020120132643A KR20120132643A KR101426158B1 KR 101426158 B1 KR101426158 B1 KR 101426158B1 KR 1020120132643 A KR1020120132643 A KR 1020120132643A KR 20120132643 A KR20120132643 A KR 20120132643A KR 101426158 B1 KR101426158 B1 KR 101426158B1
Authority
KR
South Korea
Prior art keywords
burner
optical fiber
flame
fiber preform
soot
Prior art date
Application number
KR1020120132643A
Other languages
Korean (ko)
Other versions
KR20140065292A (en
Inventor
표명환
정구범
도문현
송시호
최명수
Original Assignee
삼성전자주식회사
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 삼성전자주식회사 filed Critical 삼성전자주식회사
Priority to KR1020120132643A priority Critical patent/KR101426158B1/en
Publication of KR20140065292A publication Critical patent/KR20140065292A/en
Application granted granted Critical
Publication of KR101426158B1 publication Critical patent/KR101426158B1/en

Links

Images

Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P40/00—Technologies relating to the processing of minerals
    • Y02P40/50—Glass production, e.g. reusing waste heat during processing or shaping
    • Y02P40/57—Improving the yield, e-g- reduction of reject rates

Abstract

An apparatus for manufacturing an optical fiber preform according to the present invention includes: a burner device having a plurality of burners for generating soot through flame hydrolysis and for depositing the generated soot on a core of an optical fiber preform; And a burner control device for controlling the amount of the flame-forming gas supplied to the plurality of burners, wherein the burner control device controls the burner control device such that the plurality Thereby reducing the amount of raw material or flame-forming gas supplied to the burner.

Description

APPARATUS FOR FABRICATING OPTICAL FIBER PREFORM BACKGROUND OF THE INVENTION [0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to an optical fiber as a transmission medium for an optical signal, and more particularly, to an apparatus and a method for manufacturing an optical fiber preform as a matrix of an optical fiber.

Examples of methods for manufacturing the optical fiber preform include a modified chemical vapor deposition (MCVD) method, a vapor axial deposition (VAD) method, an outside vapor deposition (OVD), a plasma chemical vapor deposition (plasma chemical vapor deposition (PCVD) method).

In the vapor phase deposition method and the external vapor deposition method, a soot is formed by flame hydrolysis by providing a source material, a fuel gas, and the like to a burner, Is deposited on a starting member.

Increasing the burner quantity, burner spacing and feed rate to improve the efficiency of the deposition equipment leads to an increase in the length of the tapered areas located at both ends of the base material, leading to a reduction in the production yield of the base material. Such a tapered area is inevitably generated by the reciprocating motion of the burner along the longitudinal direction of the base material. It is difficult to improve the productivity of such a deposition process because an unacceptable defective portion increases as the taper region increases.

It is an object of certain embodiments of the present invention to at least partially solve, alleviate or eliminate at least one of the problems and / or disadvantages associated with the prior art.

An object of the present invention is to provide an apparatus and a method for manufacturing an optical fiber preform that can reduce the length of a tapered region of an optical fiber preform and prevent cracking or breakage of the preform.

An apparatus for manufacturing an optical fiber preform according to an aspect of the present invention includes: a burner device having a plurality of burners for generating a soot through flame hydrolysis, respectively, and depositing the resulting soot on a core of an optical fiber preform; And a burner control device for controlling the amount of the flame-forming gas supplied to the plurality of burners, wherein the burner control device controls the burner control device such that the plurality Thereby reducing the amount of raw material or flame-forming gas supplied to the burner.

Conventionally, there is a problem that the specific gravity of the tapered area of the optical fiber preform is large, which lowers the yield of the product, and the overall length of the optical fiber preform manufacturing apparatus, that is, the equipment stroke is very large. , There is a great risk that the optical fiber preform is cracked or broken.

According to the present invention, since the length and density of the tapered region of the optical fiber preform can be easily controlled, it is possible to minimize the defective section of the optical fiber preform and obtain more good optical fibers from the same size optical fiber preform, It is possible to prevent the optical fiber preform from cracking or breaking.

1 is a flowchart illustrating a method of manufacturing an optical fiber preform according to a preferred embodiment of the present invention.
2 to 10 are views for explaining a manufacturing method of the present invention.

The present invention can be variously modified and may have various embodiments, and specific embodiments will be described in detail with reference to the drawings. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Terms including ordinals, such as first, second, etc., may be used to describe various elements, but the elements are not limited to these terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

FIG. 1 is a flow chart showing a method of manufacturing an optical fiber preform according to a preferred embodiment of the present invention, and FIGS. 2 to 10 are views for explaining a manufacturing method of the present invention. The manufacturing method includes steps S11 to S16.

Step S11 is a process of growing the first soot base material by soot deposition. In the present invention, a soot base material and an optical fiber base material are separately described for ease of understanding, but a soot base material may also be referred to as an optical fiber base material.

The present invention minimizes the length or the volume of the taper region in the primary soot parent material by controlling the burners individually when depositing the soot, and prevents cracking or breakage of the primary soot parent material. This tapered area refers to a region or section in which the diameter of the primary soot parent material gradually decreases toward its end.

2 is a view for explaining a process of growing a first soot base material according to a comparative example of the present invention. The burner apparatus 20 shown in Fig. 2 includes first to fourth burners 21, 22, 23 and 24.

The inner clad 12 is grown from the outer peripheral surface of the core 11 by soot deposition. The primary soot base material 10 includes a core 11 positioned at the center thereof and an inner clad 12 formed directly on the outer periphery of the core 11. The core 11 has a relatively high refractive index and the inner clad 12 surrounding the core 11 has a relatively low refractive index.

During the soot deposition, the core 11 rotates, and the burner apparatus 20 reciprocates along the longitudinal direction of the core 11. By rotating the core 11, the primary soot matrix 10 has rotational symmetry.

Each of the burners 21 to 24 faces the core 11 and injects a flame toward the outer circumferential surface of the primary soot matrix material 10 to form the inner clad 12 from the outer circumferential surface of the primary soot parent material 10 ) Is grown outward. Each of the burners 21 to 24 is provided with a raw material S containing a glass forming material SiCl 4 and a refractive index controlling material (such as GeCl 4 , POCl 3 or BCl 3 ), a fuel gas containing hydrogen such as CH 4 , And the like are provided. The fuel gas and the oxidizing gas are flame-forming gases for forming a flame. As the raw material is hydrolyzed in the flame injected from each of the burners 21 to 24, soot is generated, and the generated soot is deposited on the primary soot mother material 10.

According to this comparative example, the first to fourth burners 21 to 24 are controlled in the same manner, and each burner injects a uniform flame. According to this control method, at the end of the primary soot parent material 10, a tapered region 13 having a number of burners B'n is formed. In addition, as described below, the tapered area 13 has a length T'd equal to or greater than the distance B'd of the burners 21 to 24 multiplied by (B'n-1).

T'd > = B'd (B'n-1)

As the burner quantity, the burner interval, and the conveying speed of the burner device are increased to improve the efficiency of the burner device 20, the tapered areas 13 formed at both ends of the primary soot mother material 10 have volume or length Is increased. Such a tapered area 13 is inevitably caused by the reciprocating movement of the burner apparatus 20 along the longitudinal direction of the primary soot base material 10. If the tapered area 13 increases, defective parts which can not be used in the base material increase, so that it is difficult to improve the productivity of the first soot matrix material 10.

3 is a view illustrating a process of growing a first soot base material according to an embodiment of the present invention. The optical fiber preform manufacturing apparatus 100 shown in FIG. 3 includes a burner apparatus 110 having first to fourth burners 111, 112, 113 and 114 and a burner control apparatus 120.

The inner clad 32 is grown from the outer peripheral surface of the core 31 by soot deposition. The primary soot parent material 30 includes a core 31 located at the center thereof and an inner clad 32 formed directly on the outer periphery of the core 31. The core 31 has a relatively high refractive index and the inner cladding 32 surrounding the core 31 has a relatively low refractive index.

During the soot deposition, the core 31 rotates, and the burner apparatus 110 reciprocates along the longitudinal direction of the core 31. By rotating the core 31, the primary soot base material 30 has rotational symmetry. At this time, the burner apparatus 110 is fixed, and the primary soot base material 30 may move.

Each of the burners 111 to 114 faces the core 31 and injects a flame toward the outer circumferential surface of the primary soot matrix material 30 so that the inner clad 32 ). Each of the burners 111 to 114 is supplied with a raw material S containing a glass forming material SiCl4 and a refractive index controlling material (GeCl4, POCl3 or BCl3 or the like), a fuel gas containing hydrogen (GF ), An oxidizing gas (GO) containing oxygen, and the like are provided. The fuel gas and the oxidizing gas are flame-forming gases for forming a flame. The soot is generated as the raw material is hydrolyzed in the flame injected from each of the burners 111 to 114, and the generated soot is deposited on the primary soot mother material 30.

The primary soot base material 30 has a tapered area 33 and the tapered area 33 has a Ta 'point or position (an end point or position of the primary soot base material 30) and a Tb' (I.e., the starting point or position of the starting point 30).

The burner control device 120 reduces the flame intensity of the burner arriving at the point Tb 'when the burner device 110 moves from right to left. At this time, the flame intensity may be expressed by the temperature or the calorific value of the flame. That is, the burner control device 120 reduces the flame intensity of the burner arriving at the point Tb 'in the order of the first burner 111, the second burner 112, and the third burner 113. At this time, the burner may be controlled not to inject a flame, and the flame intensity may be controlled to decrease to 1/2 or less. The burner control device 120 may maintain the flame intensity of the fourth burner 114 arriving at the point Tb 'as it is. That is, the burner apparatus 110 reciprocates right and left. When the fourth burner 114 reaches the point Ta ', the burner apparatus 110 can change its direction from left to right again, and in this case, It is preferable that the flame intensity of the fourth burner 114 is not changed.

When the fourth burner 114 arrives at the Ta 'point, the burner apparatus 110 changes its direction from left to right again and the burner control apparatus 120 moves from the left to the right as Ta 'To increase the flame intensity of the burner back to its original state until it reaches the point. That is, the burner control device 120 increases the flame intensity of the burner arriving at the point Ta 'in the order of the third burner 113, the second burner 112, and the first burner 111.

In other words, the burner control device 120 can reduce the amounts (or the flow rates) of the raw material and / or the flame-forming gas supplied to each of the burners 111 to 113 to 1/2 or less, respectively.

It is preferable that the condition of the burner flame stabilization time < B'd / (M'v / 60) is satisfied when the time at which the flame intensity returns to the original state is the burner flame stability time. M'v is the moving speed (mm / min) of the burner apparatus 110. Since M'v has the minute unit, M'v is divided by 60 to change to the unit of seconds. The above condition indicates that, for example, the flame intensity of the next burner should increase back to the original state until the next burner arrives at the point Tb 'after the previous burner arrives at the point Tb'.

Further, when the burner flame stabilization time is taken as Fs, the optimized length T'I of the taper region 33 satisfies the condition of T'I? (M'v / 60) 占 Fs.

The burner control device 120 can control the length (or volume) and density of the tapered region 33 by controlling the amounts of the raw material and / or the flame-forming gas supplied to each of the burners 111 to 114, It is possible to prevent the breaking of the base material due to the density change.

That is, the amounts of the raw material and / or the flame-forming gas supplied to each of the burners 111 to 113 are not equal to each other over the reciprocating sections of the burners 111 to 113 corresponding to the entire length of the primary soot parent material 30 not. Here, one or both of the raw material and the flame-forming gas can be controlled. The amount of the raw material and / or the flame forming gas supplied to each of the burners 111 to 114 in the position interval of each of the burners 111 to 114 corresponding to the remaining area of the primary soot mother material 30 excluding the tapered area 33 The amounts are uniform and the amount of the raw material and / or the flame forming gas supplied to each of the burners 111 to 113 in the position interval of each of the burners 111 to 113 corresponding to the tapered region 33 is decreased and then increased . In this example, the amounts of the raw material and / or the flame-forming gas supplied to the fourth burner 114 are illustrated as being uniform, but the amount of the raw material and / or the flame-forming gas supplied to the fourth burner 114 May also change as in the case of other burners.

Step S12 is a process for dewatering the primary soot matrix material 30. [ That is, the primary soot mother material 30 is heated in an atmosphere of chlorine (Cl 2 ) gas to remove OH groups and impurities existing in the primary soot mother material 30.

FIG. 4 is a view for explaining the process of dewatering the primary soot matrix 30. The furnace 200 shown in FIG. 4 has a heater 210 and has an inlet 220 at a lower side thereof.

In the preparation step before step S12, the primary soot mother material 30 is mounted inside the furnace 200. [ Chlorine gas and helium gas are supplied to the interior of the furnace 200 through the inlet 220 and the primary soot base material 30 is heated by using the heater 210. The amount of helium gas is preferably 20 to 50 slpm, and the amount of chlorine gas is preferably 2 to 5 vol% of helium gas. For example, the primary soot base material 30 can be heated at 1130 DEG C for 120 minutes under a chlorine gas of 1.0 splm and a helium gas atmosphere of 25 splm.

Step S13 is a process for obtaining a vitrified primary optical fiber preform by sintering the dehydrated primary soot matrix 30.

5 is a view for explaining a process of sintering the dehydrated primary soot mother material 30 using the furnace 200 shown in FIG. Helium gas is supplied to the inside of the furnace 200 through the inlet port 220 while the dehydrated primary soot mother material 30 is mounted inside the furnace 200 and the dehydrated primary soot base material 30 is heated using the heater 210 The primary soot base material 30 is heated. The dehydrated primary soot mother material 30 is moved downward by the heater 210 so that the dehydrated primary soot mother material 30 in the high temperature region formed inside the furnace 200 passes from the lower end to the upper end thereof. By performing this sintering process, a vitrified primary optical fiber preform 30a is obtained. That is, the opaque primary soot base material 30 is transformed into a transparent primary optical fiber preform 30a by sintering. Since the helium gas has a high thermal conductivity, it transfers heat evenly to the inside of the primary soot matrix material 30. The amount of the helium gas is preferably 20 to 50 slpm. For example, the primary soot base material 30 can be heated at 1500 DEG C for 200 minutes under a helium gas atmosphere of 25.0 splm.

Step S14 is a process of stretching the primary optical fiber preform 30a by heating the primary optical fiber preform 30a with a heat source that does not use hydrogen. That is, in order to reduce the diameter of the primary optical fiber preform 30a and to increase the length thereof, the end of the primary optical fiber preform 30a is pulled while the primary optical fiber preform is softened. The primary optical fiber preform 30a is stretched to a predetermined diameter in consideration of the diameter ratio of the core and the clad of the optical fiber as a final product. Non-hydrogen-based heat sources include electric furnaces, plasma heaters, and the like.

6 is a view for explaining the process of heating and drawing the primary optical fiber preform 30a. The elongating device 300 includes first and second chucks 320 and 325, a furnace 330, and an outer diameter measuring device 340.

In step S14, a first dummy rod 310 is attached to the first end of the first optical fiber preform 30a, and a second dummy rod 310 is attached to the second end of the first optical fiber preform 30a, 315). The first and second dummy rods 310 and 315 extend along the central axis (or longitudinal direction) of the primary optical fiber preform 30a. The first dummy rod 310 is mounted on the first chuck 320 and the second dummy rod 315 is mounted on the second chuck 325. At this time, in order to prevent the primary optical fiber preform 30a from being bent during the stretching process, the primary optical fiber preform 30a is disposed perpendicular to the paper so that the first end is located on the lower side and the second end is located on the upper side. To this end, the first chuck 320 is disposed on the lower side and the second chuck 325 is disposed on the upper side. The furnace 330 and the outer diameter measuring device 340 are disposed around the primary optical fiber preform 30a and the outer diameter measuring device 340 is disposed on the outer surface of the furnace 330 to measure the drawn diameter of the primary optical fiber preform 30a. Lt; / RTI &gt;

Further, in the preparation step before step S14, the diameter is measured with respect to the entire length of the primary optical fiber preform 30a by using the outer diameter measuring instrument 340, and the upward movement speed of the second chuck 325, (330).

The heating temperature of the furnace 330 is raised and the furnace 330 and the outer diameter measuring device 340 are maintained at a constant distance in a state where the primary optical fiber preform 30a is rotated at a constant speed around the central axis thereof And moves the second chuck 325 upwardly. The furnace 330 moves the section from the first end to the second end of the first optical fiber preform 30a. At this time, the moving speed of the furnace 330 is faster than the moving speed of the second chuck 325. Further, the outer diameter measuring device 340 monitors the diameter of the drawn primary optical fiber preform 30b. The rotation of the primary optical fiber preform 30a prevents the occurrence of ovoid formation and bending of the primary optical fiber preform 120b and optionally the primary optical fiber preform 30a during the step S14. It may not rotate. The heating temperature of the furnace 330 is preferably 1800 to 2100 ° C. As the furnace 330, an electric resistance furnace or an electric induction furnace can be used. For example, the heating temperature of the furnace 330 is maintained at 2,000 DEG C, the moving speed of the second chuck 325 is set at 45 to 50 mm / min, the moving speed of the second chuck 325 and the moving speed of the furnace 330 The feed speed corresponding to the difference between the moving speed of the primary optical fiber preform 30a and the moving speed of the primary optical fiber preform 30a can be set to 7.5 mm / min and 1 rpm, respectively. In addition, it is preferable that the tension applied to the second chuck 325 is maintained at 100 to 200N.

7 is a cross-sectional view of the drawn primary optical fiber preform 30b. The drawn primary optical fiber preform 30b is composed of a core 31a having a diameter d and an inner clad 32a having a diameter D. Hydrogen penetration into the core 31a of the drawn primary optical fiber preform 30b is minimized so that the ratio of the diameter of the core 31a to the inner diameter of the inner clad 32a D / d may be 5.0 or less, preferably 4.1 or more and 4.5 or less.

Thereafter, the drawn primary optical fiber preform 30b is cut and divided into two, and the cut primary optical fiber preform 30b to which the first dummy rod 310 is attached is used in the following steps.

In step S15, an outer clad is grown along the radial direction of the primary optical fiber preform 30b cut on the primary optical fiber preform 30b cut by soot deposition, thereby obtaining a second soot preform. The outer clad may have the same composition and refractive index as the inner clad 32a of the cut primary optical fiber preform 30b. The outer clad is formed directly on the outer periphery of the inner clad 32a of the cut primary optical fiber preform 30b.

8 is a view for explaining a process of growing an outer clad.

The outer clad is grown using the base material manufacturing apparatus 100 shown in Fig.

The outer clad 32 is grown from the outer peripheral surface of the primary optical fiber preform 30b by soot deposition. The secondary soot parent material 30c includes a primary optical fiber preform 30b positioned at the center and an outer clad 34 formed directly on the outer periphery of the primary optical fiber preform 30b. The outer clad 34 may have the same refractive index as the inner clad 32a.

During the soot deposition, the primary optical fiber preform 30b rotates, and the burner apparatus 110 reciprocates along the longitudinal direction of the primary optical fiber preform 30b. By rotating the primary optical fiber preform 30b, the secondary soot preform 30c has rotational symmetry. At this time, the burner apparatus 110 is fixed, and the primary soot base material 30 may move.

The central axis of each of the burners 111 to 114 faces the primary optical fiber preform 30b and the flame is sprayed toward the outer circumferential face of the secondary soot parent material 30c, The clad 34 is grown. Each of the burners 111 to 114 is supplied with a raw material S containing a glass forming material SiCl4 and a refractive index controlling material (GeCl4, POCl3 or BCl3 or the like), a fuel gas containing hydrogen (GF ), An oxidizing gas (GO) containing oxygen, and the like are provided. The fuel gas and the oxidizing gas are flame-forming gases for forming a flame. Soot is generated as the raw material is hydrolyzed in the flame injected from each of the burners 111 to 114, and the generated soot is deposited on the secondary soot parent material 30c.

The tiered area 33 has a tapered area 33a and a tapered area 33b at the starting point of the second soot base material 30c Lt; RTI ID = 0.0 &gt; TI. &Lt; / RTI &gt;

The burner control device 120 reduces the flame intensity of the burner arriving at the point Tb when the burner device 110 moves from right to left. That is, the burner control device 120 reduces the flame intensity of the burner arriving at the Tb point in the order of the first burner 111, the second burner 112, and the third burner 113. At this time, the burner may be controlled not to inject a flame, and the flame intensity may be controlled to decrease to 1/2 or less. The burner control device 120 may maintain the flame intensity of the fourth burner 114 arriving at the Tb point as it is. That is, when the fourth burner 114 reaches the Ta point, the burner apparatus 110 moves back and forth from left to right, and in this case, 4 It is preferable that the flame intensity of the burner 114 is not changed.

When the fourth burner 114 arrives at the Ta point, the burner apparatus 110 changes its direction from left to right again and the burner control apparatus 120 moves from the left to the right when the burner apparatus moves from the left to the right, The flame intensity of the burner is increased again to the original state. That is, the burner control device 120 increases the flame intensity of the burner arriving at the Ta point in the order of the third burner 113, the second burner 112, and the first burner 111 in this order.

In other words, the burner control device 120 can reduce the amounts (or the flow rates) of the raw material and / or the flame-forming gas supplied to each of the burners 111 to 113 to 1/2 or less, respectively.

It is preferable that the condition of the burner flame stabilization time < B'd / (M'v / 60) is satisfied when the time at which the flame intensity returns to the original state is the burner flame stability time. M'v is the moving speed (mm / min) of the burner apparatus 110. Since M'v has the minute unit, M'v is divided by 60 to change to the unit of seconds. The above condition indicates that the flame intensity of the next burner should increase again to the original state until the next burner arrives at the Tb point after the previous burner arrives at the Tb point, for example.

Further, when the burner flame stabilization time is taken as Fs, the optimized length TI of the taper region 33 satisfies the condition of TI? (M'v / 60) 占 Fs.

The burner control device 120 can control the length (or volume) and density of the tapered region 33a by controlling the amounts of the raw material and / or the flame-forming gas supplied to each of the burners 111 to 114, It is possible to prevent the breaking of the base material due to the density change.

That is, the amount of the raw material and / or the flame-forming gas supplied to each of the burners 111 to 113 is not the same over the reciprocating sections of the burners 111 to 113 corresponding to the entire length of the secondary soot parent material 30c not. Here, one or both of the raw material and the flame-forming gas can be controlled. The amount of the raw material and / or the flame forming gas supplied to each of the burners 111 to 114 in the position interval of each of the burners 111 to 114 corresponding to the remaining area of the secondary soot mother material 30c except for the tapered area 33a The amounts are uniform and the amount of the raw material and / or the flame-forming gas supplied to each of the burners 111 to 113 in the position interval of each of the burners 111 to 113 corresponding to the tapered region 33a decreases and then increases . In this example, the amounts of the raw material and / or the flame-forming gas supplied to the fourth burner 114 are illustrated as being uniform, but the amount of the raw material and / or the flame-forming gas supplied to the fourth burner 114 May also change as in the case of other burners.

Step S16 is a process of obtaining a vitrified secondary optical fiber preform by dewatering and sintering the secondary soot parent material 30c. That is, the dehydration process of removing the OH groups and the impurities existing in the interior of the secondary soot matrix 30c is performed by heating the secondary soot matrix 30c in a chlorine gas atmosphere, and simultaneously with the dehydration process, The second secondary base material 30c is vitrified by sintering the second secondary base material 30c in a helium gas atmosphere.

9 is a view for explaining the process of dewatering and sintering the second soot base material 30c using the furnace 200 shown in FIG. Helium gas and chlorine gas are supplied to the inside of the furnace 200 through the inlet port 220 while the secondary soot base material 30c is mounted inside the furnace 200 and the heater 210 is used to supply the heater 2 Thereby heating the tea soot base material 30c. The secondarily arranged soot base material 30c is moved downward at a predetermined speed so that the high temperature region formed inside the furnace 200 is passed by the heater 210 from the lower end to the upper end of the secondary soot parent material 30c. By performing this dehydration and sintering process, the OH groups and the impurities existing in the interior of the secondary soot matrix 30c are removed, and at the same time, the vitrified secondary optical fiber preform 30d is obtained. That is, the opaque secondary soot base material 30c is changed into a transparent secondary optical fiber preform 30d by dewatering and sintering.

The amount of helium gas is preferably 10 to 20 slpm, and the amount of chlorine gas is preferably 1 to 4 vol% of the amount of helium gas. For example, the secondary soot base material can be heated at 1500 DEG C for 300 minutes under a chlorine gas of 0.375 splm and a helium gas atmosphere of 15.0 splm.

Conventionally, the second soot base material is only sintered without dewatering. However, in the present invention, the dehydration and sintering of the second soot base material 30c can reduce the loss due to the OH groups of the low moisture loss optical fiber manufactured subsequently.

10 is a diagram showing a secondary optical fiber preform 30d. 10 (a) is a perspective view of the secondary optical fiber preform 30d, and FIG. 10 (b) is a sectional view of the secondary optical fiber preform 30d. As shown in the figure, the secondary optical fiber preform 30d has a core 31b located at the center thereof, an inner clad 32b surrounding the core 31b, an outer clad 34a surrounding the inner clad 32b, .

Thereafter, the secondary optical fiber preform 30d produced by the above-described method is taken out to the low moisture loss optical fiber through the process described below. The low moisture loss optical fiber has the same composition and diameter ratio as the secondary optical fiber preform 30d. The core of the low moisture loss optical fiber serves as a transmission medium of the optical signal, the inner clad functions to confine the optical signal in the core, and the outer clad functions to increase the diameter of the low moisture loss optical fiber. The diameter ratio of the core, the inner clad and the outer clad of the low moisture loss optical fiber is the same as the diameter ratio of the core 31b, the inner clad 32b and the outer clad 34a of the secondary optical fiber preform 30d.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. Therefore, the scope of the present invention should not be limited by the described embodiments but should be determined by the equivalents of the claims and the claims.

The present invention relates to an optical fiber preform manufacturing apparatus and a method of manufacturing the optical fiber preform and a method of manufacturing the same. Fourth burner

Claims (4)

In an apparatus for manufacturing an optical fiber preform,
A burner device having a plurality of burners each for generating a soot through flame hydrolysis and for depositing the resulting soot on the core of the optical fiber preform;
And a burner control device for controlling the amount of the flame-forming gas supplied to the plurality of burners,
Wherein the burner control device decreases the amount of the raw material or the flame forming gas supplied to the plurality of burners in the position interval of the burner device corresponding to the tapered area where the diameter of the optical fiber preform gradually decreases, / RTI &gt;
Wherein when the moving speed of the burner device is M'v mm / min and the interval between the burners is B'd mm, the burner is a burner in which the reduced flame intensity of each burner returns to the original state, And the flame stabilization time is shorter than B'd / (M'v / 60). The method according to claim 1,
Wherein the burner control device reduces an amount of a raw material or a flame forming gas supplied to each burner at a start position of the tapered region. 3. The method of claim 2,
Wherein the burner control device increases the amount of the raw material or the flame forming gas supplied to each burner at the end position of the tapered region again. The method according to claim 1,
Wherein the burner control device reduces the amount of raw material or flame-forming gas supplied to each burner to 1/2 or less.
KR1020120132643A 2012-11-21 2012-11-21 Apparatus for fabricating optical fiber preform KR101426158B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020120132643A KR101426158B1 (en) 2012-11-21 2012-11-21 Apparatus for fabricating optical fiber preform

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020120132643A KR101426158B1 (en) 2012-11-21 2012-11-21 Apparatus for fabricating optical fiber preform

Publications (2)

Publication Number Publication Date
KR20140065292A KR20140065292A (en) 2014-05-29
KR101426158B1 true KR101426158B1 (en) 2014-08-01

Family

ID=50892247

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020120132643A KR101426158B1 (en) 2012-11-21 2012-11-21 Apparatus for fabricating optical fiber preform

Country Status (1)

Country Link
KR (1) KR101426158B1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101655271B1 (en) * 2016-04-27 2016-09-07 주식회사 에스티아이 Method for producing optical fiber preform having good production efficiency

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6694915B2 (en) * 2018-06-12 2020-05-20 株式会社フジクラ Method for producing porous glass fine particles and method for producing optical fiber preform
KR102612244B1 (en) * 2023-03-14 2023-12-11 비씨엔씨 주식회사 A device capable of controlling cracks in silica soot through section-by-section heat quantity control
KR102612247B1 (en) * 2023-03-14 2023-12-11 비씨엔씨 주식회사 A DEVICE CAPABLE OF CONTROLLING the protrusion IN SILICA SOOT BY CONTROLLING THE DESTANCE BETWEEN THE BURNER AND THE MANDREL SURFACE

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20040057995A (en) * 2002-12-25 2004-07-02 신에쓰 가가꾸 고교 가부시끼가이샤 Method of Processing Preform for Optical Fiber and Apparatus Therefor
KR100755420B1 (en) * 2000-07-31 2007-09-04 신에쓰 가가꾸 고교 가부시끼가이샤 Glass base material producing device and glass base material producing method

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100755420B1 (en) * 2000-07-31 2007-09-04 신에쓰 가가꾸 고교 가부시끼가이샤 Glass base material producing device and glass base material producing method
KR20040057995A (en) * 2002-12-25 2004-07-02 신에쓰 가가꾸 고교 가부시끼가이샤 Method of Processing Preform for Optical Fiber and Apparatus Therefor

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101655271B1 (en) * 2016-04-27 2016-09-07 주식회사 에스티아이 Method for producing optical fiber preform having good production efficiency
WO2017188660A1 (en) * 2016-04-27 2017-11-02 주식회사 에스티아이 Production efficiency-improved method for manufacturing optical fiber preform

Also Published As

Publication number Publication date
KR20140065292A (en) 2014-05-29

Similar Documents

Publication Publication Date Title
CN105060701B (en) A kind of preparation method of large scale bend-insensitive multimode optical fiber preform
CN102757179B (en) Method for preparing large-size optical fiber preform
US9656902B2 (en) Method of manufacturing preforms for optical fibres having low water peak
KR101426158B1 (en) Apparatus for fabricating optical fiber preform
WO2019142878A1 (en) Method for manufacturing optical fiber preform, optical fiber preform, method for manufacturing optical fiber, and optical fiber
CN104098265A (en) Collapsing manufacture method with improved axial evenness for core rods of optical fiber preforms
CN1472150A (en) Method for producing fibre-optical precast stick
US9416045B2 (en) Method of manufacturing preforms for optical fibres having low water peak
CN105236731A (en) Melt collapsing and stretching technology of optical fiber preform core rod
JP5744070B2 (en) Method for manufacturing optical fiber and tubular semi-finished product
US20060179889A1 (en) Method for dehydrating and consolidating a porous optical fiber preform
JP2014101236A (en) Production method of optical fiber preform, and optical fiber
WO2007054961A2 (en) Optical fiber preform having large size soot porous body and its method of preparation
US20070157674A1 (en) Apparatus for fabricating optical fiber preform and method for fabricating low water peak fiber using the same
JP5533205B2 (en) Glass base material manufacturing method
US6928841B2 (en) Optical fiber preform manufacture using improved VAD
US20080053155A1 (en) Optical fiber preform having large size soot porous body and its method of preparation
JP2011020861A (en) Method for producing optical fiber preform
US20040099013A1 (en) Optical fibers and methods of fabrication
KR100762611B1 (en) Method for fabricating optical fiber preform and method for fabricating optical fiber using the same
JP2017226569A (en) Production method of optical fiber preform, and production method of glass fine particle deposit
JP4252834B2 (en) Optical fiber preform manufacturing method
JP3953855B2 (en) Method for producing porous base material
JP6081534B2 (en) Optical fiber manufacturing method and optical fiber manufacturing apparatus
JPH0986948A (en) Production of porous glass base material for optical fiber

Legal Events

Date Code Title Description
A201 Request for examination
N231 Notification of change of applicant
E902 Notification of reason for refusal
E701 Decision to grant or registration of patent right
GRNT Written decision to grant
FPAY Annual fee payment

Payment date: 20170713

Year of fee payment: 4

FPAY Annual fee payment

Payment date: 20180628

Year of fee payment: 5

FPAY Annual fee payment

Payment date: 20190702

Year of fee payment: 6