KR100809185B1 - Automatic aligning apparatus between optical fiber preform and electrical furnace by using optical sensor and aligning method using the same - Google Patents

Abstract

An automatic aligning apparatus between an optical fiber preform and an electrical furnace by using an optical sensor and an aligning method using the same are provided to improve the non-circularity of the optical fiber preform and reduce a PMD(Polarization Mode Dispersion) characteristic. An automatic aligning apparatus between an optical fiber preform(10) and an electrical furnace(30) includes preform rotating chucks(40a,40b), the electrical furnace, a plurality of optical signal transmitters(80a,80b), a plurality of optical power meters(85a,85b), a control unit(60), and an electrical furnace position adjusting unit(70). The preform rotating chucks rotate the optical fiber preform in a predetermined direction. The electrical furnace heats the optical fiber preform. The optical signal transmitters irradiate optical signals to the electrical furnace in parallel to an axis of the optical fiber preform. The control unit receives the intensity of the optical signal measured by the optical power meters and analyzes an arrangement state of the electrical furnace. The electrical furnace position adjusting unit minutely moves the electrical furnace and arranges the electrical furnace.

Description

Automatic alignment device between optical fiber preform and electrical furnace by using optical sensor and Aligning method using the same}

The following drawings attached to this specification are illustrative of preferred embodiments of the present invention, and together with the detailed description of the invention to serve to further understand the technical spirit of the present invention, the present invention is a matter described in such drawings It should not be construed as limited to.

1 is a cross-sectional view showing a conventional technology for manufacturing an optical fiber base material by a crystal chemical vapor deposition (MCVD) using an electric furnace.

2 is a cross-sectional view showing a configuration of an optical fiber base material manufactured by an MCVD process.

FIG. 3 is a schematic diagram of an apparatus for aligning an electric furnace in an optical fiber base material manufacturing according to the related art.

4 is a cross-sectional view showing the electric furnace configuration of the electric furnace aligning device in the optical fiber base material manufacturing according to the prior art.

FIG. 5 is a schematic diagram illustrating an apparatus for arranging an electric furnace used in manufacturing an optical fiber base material using an electric furnace according to a preferred embodiment of the present invention.

6 is a block diagram showing the control signal flow of the control unit according to an embodiment of the present invention.

7 and 8 are diagrams schematically showing an operation of aligning an electric furnace according to a preferred embodiment of the present invention.

9 is a graph showing a relationship between an optical signal intensity and an alignment center point according to a preferred embodiment of the present invention.

10 is a flowchart illustrating a method of arranging an electric furnace according to the first embodiment of the present invention.

11 is a flowchart illustrating a method of arranging an electric furnace according to a second embodiment of the present invention.

<Description of main reference numerals in the drawings>

10 ... optical fiber substrate 30 ... electrically

60 control unit 70 electric furnace position adjustment unit

80 ... light transmitter 85 ... light power meter

The present invention relates to an automatic alignment device of an optical fiber base material and an electric furnace using an optical sensor. More specifically, before the optical fiber base material is manufactured, the optical fiber base material and the shafts of the electric furnace are aligned with each other, and the optical fiber base material and the electric furnace are also processed. The present invention relates to an automatic alignment device of an optical fiber base material and an electric furnace using an optical sensor that maintains the alignment state in an optimal state by checking the alignment state of the antenna in real time, and an alignment method using the same.

Representative process technologies for manufacturing optical fiber base materials by vapor deposition generally include Vapor-Phase Axial Deposition (VAD), Outside Vapor Deposition (OVD), and Modified Chemical Vapor Deposition. Deposition; MCVD) method can be mentioned.

Among them, the MCVD method injects a carrier gas together with a reactor gas into a hollow tube, and heats the base material using a heat source so that the deposition by thermal oxidation reaction inside the base material is repeatedly performed in units of layers. clad) and core (core) is a method for forming sequentially.

Conventionally, the tube was heated using an oxygen-hydrogen torch as a heat source. However, the MCVD process using the torch has a limitation in heating the rotating quartz tube to a uniform temperature, and the oxygen-hydrogen torch generates a hydrogen impurity such as water as a reaction byproduct, causing a loss of OH absorption of the optical fiber. Therefore, a method of suppressing hydrogen impurity generation by heating a quartz tube in a closed electrical furnace instead of an oxygen-hydrogen torch has been proposed. In this method, a furnace is installed to surround the rotating quartz tube, and the deposition process is performed while moving the electric furnace with respect to the rotating tube in the longitudinal direction of the tube, for example, about 150 mm / min. In the case of using the electric furnace as a heat source, the gas phase chemical reaction efficiency is relatively high, so that the generation characteristics of the soot particles are improved compared to the case of using the torch as a heat source.

More specifically, Figure 1 is a cross-sectional view showing a conventional technique for manufacturing an optical fiber base material by a crystal chemical vapor deposition (MCVD) using an electric furnace.

Referring to FIG. 1, in the MCVD method, a quartz tube 1 is mounted on both chucks (not shown) of a lathe and a halide series such as SiCl ₄ , GeCl ₄ , and POCl ₃ is placed inside the rotating quartz tube 1. The soot forming gas of is added together with oxygen gas. In addition, the reciprocating transfer of the furnace 3 along the longitudinal direction (axial direction) of the quartz tube 1 is carried out so that the reactant (suit) 2 is deposited on the inner wall of the tube by a thermophoresis phenomenon. While heating, the quartz tube 1 is heated. The deposited layer of clad 4 and core 5 is then formed. Here, the reaction in which the soot 2 is produced is represented by the following reaction scheme.

SiCl ₄ (g) ₊ O ₂ (g) → SiO ₂ (s) + 2Cl ₂ (g)

GeCl ₄ (g) + O ₂ (g) → GeO ₂ (s) + 2Cl ₂ (g)

At this time, the SiO ₂ particles generated according to the reaction of the source gas determines the diameter of the clad and the core, the GeO ₂ particles to adjust the refractive index.

2 is a cross-sectional view showing a configuration of an optical fiber base material manufactured by an MCVD process.

Referring to FIG. 2, the optical fiber base material 10 is composed of a core 5 and a clad 4. As the deposition process proceeds, the cladding 4 layer is deposited first, followed by the core 5 layer. Here, the diameter of the deposited core 5 is represented by d, and the diameter of the deposited clad 4 is represented by D.

As described above, the adoption of an electric furnace as a heat source of the MCVD process has the advantage of not generating hydroxyl groups, such as oxygen / hydrogen flames, but because the clad and core are sequentially deposited inside the quartz tube 1, it is preferable in the longitudinal direction. In order to obtain optical characteristics, it is necessary to manage specific ratios in which the inside and outside diameters of the base are kept constant.

However, if the alignment between the quartz tube fixed to both chucks and the electric furnace is misaligned or misaligned due to other factors during the process, an uneven temperature gradient is formed inside and outside the quartz tube, which is the base material, and as a result, deposition proceeds. Undesirable deformation of the inside and outside diameters of the quartz tube causes changes in flow rate, flow rate, and temperature conditions before and after deposition, resulting in a change in deposition efficiency or deposition rate.

Therefore, when manufacturing the optical fiber base material using the electric furnace, prior work must be carried out to accurately align the alignment between the electric furnace and the quartz tube before embarking on the process.

3 is a view schematically showing a process of adjusting the alignment of the electric furnace by using the alignment rod in the manufacturing of the optical fiber base material using the electric furnace according to the prior art, Figure 4 is a cross-sectional view of the electric furnace shown in FIG. It is a cross section.

Referring to the drawings, a conventional furnace aligning method will be described. In the related art, in order to check or correct an alignment of a quartz tube and an electric furnace before the optical fiber base material fabrication process, an alignment rod 15 having a constant outer diameter is used instead of the quartz tube. 40a, 40b and by rotating the electric furnace 30 together with the alignment bar cover 20, by adjusting the clearance gap 25 between the alignment bar cover 20 and the inner diameter of the electric furnace 30 by quartz The axes of the tube and the electric furnace 30 are aligned with each other.

However, the alignment method as described above has the disadvantage that the reliability of the alignment state is lowered because the alignment state is determined according to the individual subjective measurement point of view. In addition, other misalignments that occur after the start of the process, such as non-uniform vibrations in the furnace transfer device, and micro-alignment defects in the furnace caused by poor physical contact of the devices constituting the quartz tube or the drive mechanism of the furnace, There is a limit to checking or correcting.

The present invention has been made to solve the problems of the prior art as described above, in the manufacturing process of the optical fiber base material, the optical fiber base material and the electric furnace automatically using the optical sensor that can align the optical fiber base material and the electric furnace quickly, objectively and with high precision It is an object of the present invention to provide an alignment device and an alignment method using the same.

Another technical problem to be achieved by the present invention is an automatic alignment apparatus of an optical fiber base material and an electric furnace using an optical sensor that continuously monitors the alignment state between the optical fiber base material and the electric furnace and corrects it in real time even when an abnormality occurs during the manufacturing process of the optical fiber base material and The purpose is to provide a sorting method using the same.

In order to achieve the above object, an apparatus for aligning an optical fiber base material and an electric furnace in a process of manufacturing an optical fiber base material by a Modified Chemical Vapor Deposition (MCVD) process using an electric furnace according to the present invention is directed toward an electric furnace at a fixed point. An optical signal transmitter which emits an optical signal and transmits an optical signal having a constant intensity and parallel to a central axis of the optical fiber base material; An optical power meter installed in the electric furnace so as to face the optical signal transmitter and receiving an optical signal transmitted from the optical signal transmitter to output an intensity value of the optical signal; A control unit for outputting a feedback control signal by comparing the optical signal intensity value output from the optical power meter with a reference optical signal intensity value so that the measured optical signal intensity value follows the reference optical signal intensity value; And an electric furnace position adjusting unit for adjusting the position of the electric furnace according to the feedback control signal to match the central axis of the optical fiber base material with the central axis of the electric furnace. Characterized in that it comprises a.

 In the present invention, the optical signal transmitter is preferably installed on the left and right base material rotating chuck to rotate the optical fiber base material in a constant direction.

In the present invention, the optical signal intensity value output from the optical power meter preferably includes a first optical signal intensity value input from the left optical signal transmitter and a second optical signal intensity value input from the right optical signal transmitter. .

Preferably, the reference optical signal intensity value is an optical signal intensity value output from the optical power meter when the electric furnace and the optical fiber base material are in good alignment. Meanwhile, when the reference optical signal intensity value includes the first and second optical signal intensity values, it is preferable that the first optical signal intensity value and the second optical signal intensity value coincide with each other.

Preferably, the electric furnace position adjusting unit includes a moving unit for precisely moving the electric furnace left and right or up and down about the axis of the electric furnace position adjusting unit so as to align the optical fiber base material by receiving the feedback control signal from the control unit.

In order to achieve the above technical problem, a method of mutually aligning an optical fiber base material and an electric furnace in preparation for manufacturing an optical fiber base material by a modified chemical vapor deposition (MCVD) process using an electric furnace according to an aspect of the present invention includes: (a) an optical fiber; Moving the electric furnace at a constant speed toward the inlet through which the optical fiber base material is introduced from the process start point to align the optical fiber base material with the electric furnace before the base material is manufactured; (b) the optical signal transmitter transmitting the optical signal having a constant intensity and parallel to the central axis of the optical fiber base material under the control of the controller; (c) the optical power meter outputting an intensity value of the optical signal received from the optical signal transmitter; (d) the control unit comparing the intensity value of the optical signal output from the optical power meter with a reference optical signal intensity value and outputting a feedback control signal such that the measured optical signal intensity value follows the reference optical signal intensity value; (e) an electric furnace position adjusting unit adjusting the position of the electric furnace according to the feedback control signal to match the central axis of the optical fiber base material with the central axis of the electric furnace; And (f) placing the furnace at the beginning of the process once the mutual alignment of the fiber optic substrate with the furnace is complete; It includes.

Method of aligning the optical fiber base material and the electric furnace in the process of manufacturing the optical fiber base material by the Modified Chemical Vapor Deposition (MCVD) process using an electric furnace according to another aspect of the present invention for achieving the technical problem, (a) Manufacturing the base material and starting the electric furnace at a slow speed toward the inlet through which the optical fiber base material is introduced in the horizontal lathe to manufacture the optical fiber base material; (b) an optical signal transmitter transmitting the optical signal having a constant intensity and parallel to the central axis of the optical fiber base material under the control of the controller; (c) the optical power meter outputting an intensity value of the optical signal received from the optical signal transmitter; (d) the control unit comparing the intensity value of the optical signal output from the optical power meter with a reference optical signal intensity value and outputting a feedback control signal such that the measured optical signal intensity value follows the reference optical signal intensity value; And (e) an electric furnace position adjusting unit adjusting the position of the electric furnace when an abnormality occurs in the alignment state of the electric furnace according to the feedback control signal to match the center axis of the optical fiber base material with the center axis of the electric furnace. It includes.

Preferably, the process of aligning the optical fiber base material and the electric furnace is continuously performed during the process of manufacturing the optical fiber base material.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

FIG. 5 is a schematic block diagram of an apparatus for arranging an electric furnace used in manufacturing an optical fiber base material using an electric furnace according to a preferred embodiment of the present invention. FIG. 6 is a flow diagram of a control signal of a controller according to a preferred embodiment of the present invention. It is a block block diagram which shows the following.

5 and 6, the automatic alignment device of the optical fiber base material and the electric furnace according to the present invention, both ends of the optical fiber base material 10 is mounted, the base material rotating chuck to rotate the optical fiber base material 10 in a predetermined direction ( 40a and 40b and an electric furnace 30 installed to surround the outer circumferential surface of the optical fiber base material 10 to heat the optical fiber base material 10 and to reciprocate between both ends of the optical fiber base material 10, and the base material. A plurality of optical signal transmitters 80a and 80b installed on the rotary chucks 40a and 40b to irradiate an optical signal in parallel with an optical fiber base material axis toward the electric furnace 30, and each of the optical signal transmitters 80a 80b) to control the optical signal transmission of the plurality of optical power meters (85a, 85b) and the optical signal transmitters (80a, 80b) installed in the upper portion of the electric furnace (30), and the optical power meter (85a) 85b) receives the optical signal strength measured in the electric furnace 30 Receiving applying a feedback control signal (6) from the controller 60, the control unit 60 to interpret the alignment condition and a positioning part (70) into an electrical aligning to finely move the 30 to the electric.

 As shown in FIGS. 5 and 6, the optical signal transmitters 80a and 80b receive the feedback control signal 6 of the controller 60 and are in parallel with and constant with the central axis of the optical fiber base material 10. And generate the first and second optical signals 8a and 8b. The optical signals 8a and 8b are irradiated from the left and right optical signal transmitters 80a and 80b toward the optical power meters 85a and 85b located above the electric furnace 30 from both left and right directions.

The optical power meters 85a and 85b measure the intensities of the first and second optical signals 8a and 8b irradiated from the optical signal generators 80a and 80b in both directions. The optical signal intensity information 9 including the intensity of the second optical signals 8a and 8b is transmitted to the controller 60.

The control unit 60 controls the optical signal transmitters 80a and 80b to irradiate the constant first and second optical signals 8a and 8b, and receives the signals from the optical power meters 85a and 85b. The optical signal intensity information 9 is compared with the reference optical signal intensity information 5 stored in the controller 60. If there is an error compared to the reference optical signal intensity information 5, the feedback control signal 7 for finely adjusting the electric furnace 30 to follow the reference optical signal intensity value is generated.

Here, the reference optical signal intensity information (5) is installed to newly input the optical fiber base material manufacturing apparatus into the optical fiber base material manufacturing process, the optical fiber base material (in preparation for checking the optical fiber base material manufacturing device and finally starting the process) 10) and the first and second optical signal intensities measured with the alignment of the electric furnace 30 exactly matched, wherein the first and second optical signal intensities coincide with each other.

In addition, the reference optical signal intensity information (5) is a value measured by aligning the optical fiber base material 10 and the electric furnace 30 again after the movement or regular inspection of the optical fiber base material manufacturing apparatus is completed. The information 5 can be updated.

The electric furnace position adjusting unit 70 receives the feedback control signal 7 applied by the control unit 60 to finely move the electric furnace 30 to move the optical fiber base material 10 and the electric furnace 30. Align it.

7 and 8 are diagrams schematically showing an operation of aligning an electric furnace according to a preferred embodiment of the present invention.

As shown in FIG. 7, the first and second optical signals 8a and 8b are irradiated from the optical signal transmitters 80a and 80b to the optical power meters 85a and 85b. The optical power meters 85a and 85b measure the strengths of the first and second optical signals 8a and 8b and transmit them to the controller 60. The controller 60 compares the optical signal intensity information 9 applied from the optical power meters 85a and 85b with the reference optical signal intensity information 5 so that the alignment state of the electric furnace 30 is poor. If so, the feedback control signal 7 is applied to the electric furnace position adjusting unit 70. The electric furnace position adjusting unit 70 moves the electric furnace 30 to the upper side (U) and the lower side (D) finely around the adjusting unit shaft 75 according to the feedback control signal 7. Is repeated by a feedback control loop so that the control unit 60 continuously follows the optical signal intensity information 9 transmitted from the optical power meters 85a and 85b to the reference optical signal intensity information 5. The furnace 30 is aligned with the vertical alignment point.

In addition, as shown in FIG. 8, after the vertical alignment of the electric furnace 30 is performed, the controller 60 controls the optical signal intensity information 9 and the optical signal applied from the optical power meters 85a and 85b. When it is determined that the alignment state of the electric furnace 30 is poor by comparing the reference optical signal intensity information 5, the feedback control signal 7 is applied to the electric furnace position adjusting unit 70. The electric furnace position adjusting unit 70 moves the electric furnace 30 to the left (L) and the right (R) finely about the adjusting unit shaft 75 according to the feedback control signal (7), By repeating the process by a feedback control loop, the control unit 60 continuously follows the optical signal intensity information 9 transmitted from the optical power meters 85a and 85b to the reference optical signal intensity 5. Align the furnace 30 to the left and right alignment point. When the electric furnace 30 is aligned to the alignment point in the upper, lower, left, and right through the above process, the electric furnace 30 and the optical fiber base material 10 achieve a desirable alignment state.

9 is a graph showing a relationship between an optical signal intensity and an alignment center point according to a preferred embodiment of the present invention.

Referring to FIG. 9, the optical signal strength 90 according to the left and right changes in the left and right sides aligned, the optical signal strength 91 according to the vertical change in the top and bottom sides aligned, the left and right alignment points P1, and the top and bottom Alignment point P2 and reference optical signal intensity 9 are respectively shown.

As shown in FIG. 9, when the center point of the electric furnace 30 deviates from the left and right alignment center point P1, the optical signal intensity changes. Likewise, the center point of the electric furnace 30 is the upper and lower sides. When the alignment center point P2 deviates, the optical signal intensity changes. However, when the position of the electric furnace 30 is finely adjusted by the feedback control according to the present invention, the center point of the electric furnace 30 gradually faces toward the left and right alignment center point P1 and the vertical alignment center point P2. As a result, the optical fiber base material 10 and the electric furnace 30 are in a desirable alignment state.

10 is a flowchart illustrating a method for arranging an electric furnace according to the first embodiment of the present invention.

Referring to FIG. 10, a method of aligning an optical fiber base material and an electric furnace in a preparation process of manufacturing an optical fiber base material by a modified chemical vapor deposition (MCVD) process using an electric furnace includes an electric furnace alignment preparation step (S100) and an optical signal transmitting step. (S200), optical signal intensity measurement step (S300), furnace alignment state analysis step (S400), feedback control signal transmission step (S500), furnace alignment step (S600), and the process preparation step (S700) do.

In the electrical furnace alignment preparation step (S100), the optical fiber base material 10 before the optical fiber base material manufacturing is mounted on the base material rotary chuck 40 to align the optical fiber base material and the electric furnace 30 and to prepare the optical fiber base material optical fiber base material The electric furnace 30 installed on the horizontal shelf 50 of the manufacturing apparatus moves at a constant speed toward the inlet through which the optical fiber base material 10 is introduced from the process starting point.

In the optical signal transmission step (S200), the optical signal transmitter 80 transmits the optical signal 8 having a constant and parallel with the central axis of the optical fiber base material 10 under the control of the control unit 60.

In the optical signal intensity measuring step (S300), the optical power meter 85 receives the optical signal 8 from the optical signal transmitter 80, measures the optical signal intensity, and transmits the optical signal intensity to the controller 60.

In the electric furnace alignment state analysis step (S400), the controller 60 analyzes the alignment state of the current electric furnace 30 based on the optical signal intensity information 9 transmitted from the optical power meter 85. The alignment state analysis analyzes the alignment state by comparing the difference between the reference optical signal intensity information 5 stored in the control unit 60 and the optical signal intensity measured by the current optical power meter. The alignment of the electric furnace 30 is performed. If the condition is good, there is no difference between the reference optical signal strength and the current optical signal strength, and the electric furnace 30 constitutes other factors such as non-uniform vibration of the electric transfer medium, an optical fiber base material or a driving mechanism of the electric furnace. If the electric furnace 30 is in a misalignment state due to a physical contact of the device, a mistake of the operator, or the like, a difference occurs between the reference light signal intensity and the current light signal intensity. It can be interpreted as defective.

In the feedback control signal transmission step (S500), when the difference between the reference optical signal intensity and the current optical signal intensity occurs in the control unit 60, it is determined that the alignment state of the electric furnace 30 is an error of the optical signal strength The feedback control signal 7 for driving the electric furnace position adjusting unit 70 is transmitted to the electric furnace position adjusting unit 70 so as to predict and correct the alignment error range of the electric furnace 30 based on the magnitude of the value.

In the furnace aligning step (S600), the electric furnace position adjusting unit 70 receives the control of the feedback control signal 7 from the controller 60, and moves the electric furnace 30 up, down, left, and right about the adjustment shaft 75. The movement of the electric furnace 30 by the electric furnace position adjusting unit 70 is continuously performed so that the current optical signal intensity follows the reference optical signal intensity in the controller 60. When the alignment state of the electric furnace 30 is achieved through such a process, the electric furnace position adjusting unit 70 maintains the current state of the electric furnace 30.

In the process preparation step (S700), when the completion of the alignment of the optical fiber base material 10 and the electric furnace 30 and the preparation for manufacturing the optical fiber base material is completed, the electric furnace 30 is positioned as a process starting point.

11 is a flowchart illustrating a method of arranging an electric furnace according to a second embodiment of the present invention.

Referring to FIG. 11, a method of mutually aligning an optical fiber base material and an electric furnace in a process of manufacturing an optical fiber base material by a modified chemical vapor deposition (MCVD) process using an electric furnace includes an optical fiber base material manufacturing step (S150) and an optical signal transmitting step ( S250), an optical signal intensity measuring step (S350), an electric furnace alignment state analysis step (S450), a feedback control signal transmission step (S550), an electric furnace alignment step (S650), and an electric furnace alignment monitoring step (S750). do.

In the optical fiber base material manufacturing step (S150), the optical fiber base material manufacturing is started and the electric furnace 30 installed on the horizontal shelf 50 of the optical fiber base material manufacturing apparatus is slow toward the inlet through which the optical fiber base material 10 is introduced from the process starting point. Moving at speed produces fiber optic substrates.

In the optical signal transmission step (S250), the optical signal transmitter 80 is controlled by the control unit 60 to transmit the optical signal 8 having a constant and parallel to the central axis of the optical fiber base material 10.

In the optical signal intensity measuring step (S350), the optical power meter 85 receives the optical signal 8 from the optical signal transmitter 80, measures the optical signal strength, and transmits the optical signal intensity to the controller 60.

In the electric furnace alignment state analysis step (S450), the controller 60 analyzes the alignment state of the current electric furnace 30 based on the optical signal intensity information 9 transmitted from the optical power meter 85. The alignment state analysis analyzes the alignment state by comparing the difference between the reference optical signal intensity information 5 stored in the control unit 60 and the optical signal intensity measured by the current optical power meter. The alignment of the electric furnace 30 is performed. If the condition is good, there is no difference between the reference optical signal strength and the current optical signal strength, and the electric furnace 30 constitutes other factors such as non-uniform vibration of the electric transfer medium, an optical fiber base material or a driving mechanism of the electric furnace. If the electric furnace 30 is in a misalignment state due to a physical contact of the device, a mistake of the operator, or the like, a difference occurs between the reference light signal intensity and the current light signal intensity. It can be interpreted as defective.

In the feedback control signal transmission step (S550), when the difference between the reference optical signal intensity and the current optical signal intensity occurs in the control unit 60, it is determined that the alignment state of the electric furnace 30 is an error of the optical signal strength The feedback control signal 7 for driving the electric furnace position adjusting unit 70 is transmitted to the electric furnace position adjusting unit 70 so as to predict and correct the alignment error range of the electric furnace 30 based on the magnitude of the value.

In the furnace aligning step (S650), the electric furnace position adjusting unit 70 receives the control of the feedback control signal 7 from the control unit 60 and adjusts the electric furnace when the abnormality occurs in the alignment state of the electric furnace 30. 75, and move finely up, down, left and right, and the movement of the electric furnace 30 by the electric furnace position adjusting unit 70 is continuously performed in the control unit 60 so that the current optical signal intensity follows the reference optical signal intensity. Is done. When the alignment state of the electric furnace 30 is achieved through such a process, the electric furnace position adjusting unit 70 maintains the current state of the electric furnace 30.

In the furnace alignment monitoring step (S750), continuously monitor the state of the furnace alignment during the optical fiber base material manufacturing process, and automatically sorts the electricity when an abnormality occurs to maintain the desired furnace alignment state.

Example  And Comparative example

Table 1 below shows the difference between the process time and the production speed before and after the fabrication of the optical fiber base material and the electric furnace by the conventional alignment method and the automatic alignment method according to the present invention.

Process time before and after manufacturing Production speed existing After applying the technology 22.89km / hr → 24.51km / hr (1.61km / hr improvement) 38.03hr 36.53hr

As shown in Table 1, the process time before and after manufacturing takes 38.03hr when manufactured by the conventional electric furnace sorting method, the process time before and after manufacturing takes 36.53hr when manufactured by the automatic sorting method according to the invention 1.5hr It can be seen that the time is reduced.

In addition, the production speed of the optical fiber base material is 22.89 km / hr in the case of the existing method, 24.51 km / hr in the case of the method according to the present invention, it can be seen that the improvement effect of 1.61 km / hr.

As can be seen from Table 1, it can be expected to shorten the process time and increase the production speed through the automatic furnace alignment method according to the present invention.

Table 2 below shows the improvement of the specific ratio of the primary optical fiber base material when the electric furnace automatic alignment method according to the present invention is applied before and after manufacturing the primary optical fiber base material.

Primary Fiber Optic Base Material Average Specific Ratio (Prior Art) Primary optical fiber base material average specific ratio (invention) 0.52-0.82 0.15-0.3

As can be seen through Table 2, the existing primary base material average specific ratio has a specific ratio of 0.52 to 0.82. However, after applying the electric furnace automatic sorting method according to the present invention has a specific ratio of 0.15 to 0.3.

When comparing each specific ratio, it can be seen that the specific ratio is greatly improved when the automatic alignment method according to the present invention is performed.

The improvement of specific ratio improves the polarization mode dispersion (abbreviated to PMD) of the optical fiber.

Table 3 below shows the relationship between the primary matrix ratio and PMD characteristics when the alignment between the optical fiber base material and the electric furnace is manufactured by the conventional alignment method and the automatic alignment method according to the present invention.

Before applying technology After applying the technology Primary substrate specific ratio PMD [ps / km ^1/2 ] Primary substrate specific ratio PMD [ps / km ^1/2 ]  0.52-0.82 Average 0.040                   0.15-0.3 Average 0.025 maximum 0.044 maximum 0.028 Deviation 0.003 Deviation 0.003

As shown in Table 3, the primary base material specific ratio before the application of the technology is 0.52 to 0.82 and accordingly the PMD has an average value of 0.040, the maximum value is 0.044 and the deviation between the average value and the maximum value is 0.003.

After applying the present invention, the primary base material specific ratio is 0.15 to 0.3, and thus the PMD has an average value of 0.025, a maximum value of 0.028, and a deviation between the average value and the maximum value of 0.003.

As described above, when the optical fiber base material is manufactured by the electric furnace automatic alignment method according to the present invention, the primary base material specific ratio can be improved, and thus, PMD, which is a condition for improving the characteristics of the optical fiber, can be achieved. .

Although the present invention has been described above by means of limited embodiments and drawings, the present invention is not limited thereto and will be described below by the person skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of the claims.

According to an aspect of the present invention, in aligning the optical fiber base material and the electric furnace in the optical fiber base material manufacturing process, it is possible to immediately check the alignment state of the electric furnace by using an optical sensor, and it is possible to automatically align the electric furnace.

According to another aspect of the present invention, by automatically aligning the optical fiber base material and the electric furnace, it is possible to shorten the manufacturing time of the optical fiber base material to improve the production speed.

According to another aspect of the present invention, even during the manufacturing process of the optical fiber base material, it is possible to continuously monitor the alignment state of the optical fiber base material and the electric furnace and correct it when an abnormality occurs, thereby improving the specific ratio of the optical fiber base material and reducing the PMD characteristics. have.

Claims (9)

In the apparatus for aligning the optical fiber base material and the electric furnace in the process of manufacturing the optical fiber base material by MCVD (Modified Chemical Vapor Deposition) process using an electric furnace, An optical signal transmitter which emits an optical signal toward an electric furnace at a fixed point and transmits an optical signal having a constant intensity and parallel to the central axis of the optical fiber base material; An optical power meter installed in the electric furnace so as to face the optical signal transmitter and receiving an optical signal transmitted from the optical signal transmitter to output an intensity value of the optical signal; A control unit for outputting a feedback control signal by comparing the optical signal intensity value output from the optical power meter with a reference optical signal intensity value so that the measured optical signal intensity value follows the reference optical signal intensity value; And An electric furnace position adjusting unit adjusting the position of the electric furnace according to the feedback control signal to coincide with the central axis of the optical fiber base material and the electric central axis of the electric furnace; Automatic alignment device of the optical fiber base material and the electric furnace using an optical sensor comprising a. The method of claim 1, The optical signal transmitter is an automatic alignment device of the optical fiber base material and the electric furnace using an optical sensor, characterized in that installed on the left and right base material rotary chuck to rotate the optical fiber base material in a predetermined direction. The method of claim 1, The optical signal intensity value output from the optical power meter includes a first optical signal intensity value input from a left optical signal transmitter and a second optical signal intensity value input from a right optical signal transmitter. Automatic alignment device of optical fiber base material and electric furnace. The method of claim 1, The reference optical signal intensity value is an automatic alignment device of the optical fiber base material and the electric furnace using the optical sensor, characterized in that the optical signal intensity value output from the optical power meter when the electric furnace and the optical fiber base material is good alignment. The method according to claim 3 or 4, And the reference optical signal intensity value is an optical signal intensity value when the first optical signal intensity value and the second optical signal intensity value coincide with each other. The method of claim 1, The electric furnace position adjusting unit includes a moving means for precisely moving the electric furnace left and right or up and down about the axis of the electric furnace position adjusting unit to align the optical fiber base material by receiving the feedback control signal from the control unit. Automatic alignment device of optical fiber base material and electric furnace using sensor. In the method of aligning the optical fiber base material and the electric furnace in the preparation of manufacturing the optical fiber base material by MCVD (Modified Chemical Vapor Deposition) process using an electric furnace, (a) moving the electric furnace at a constant speed from the start of the process toward the inlet through which the optical fiber base material is introduced to align the optical fiber base material with the electric furnace before fabrication of the optical fiber base material; (b) the optical signal transmitter transmitting the optical signal having a constant intensity and parallel to the central axis of the optical fiber base material under the control of the controller; (c) the optical power meter outputting an intensity value of the optical signal received from the optical signal transmitter; (d) the control unit comparing the intensity value of the optical signal output from the optical power meter with a reference optical signal intensity value and outputting a feedback control signal such that the measured optical signal intensity value follows the reference optical signal intensity value; (e) an electric furnace position adjusting unit adjusting the position of the electric furnace according to the feedback control signal to match the central axis of the optical fiber base material with the central axis of the electric furnace; And (f) placing the furnace at the beginning of the process when the alignment of the fiber optic substrate with the furnace is complete; Alignment method of the optical fiber base material and the electric furnace using an optical sensor comprising a. In the method of aligning the optical fiber base material and the electric furnace in the process of manufacturing the optical fiber base material by the Modified Chemical Vapor Deposition (MCVD) process using an electric furnace, (a) fabrication of the optical fiber base material is started and the electric furnace moves at a slow speed toward the inlet through which the optical fiber base material is introduced in the horizontal lathe to manufacture the optical fiber base material; (b) the optical signal transmitter transmitting the optical signal having a constant intensity and parallel to the central axis of the optical fiber base material under the control of the controller; (c) the optical power meter outputting an intensity value of the optical signal received from the optical signal transmitter; (d) the control unit comparing the intensity value of the optical signal output from the optical power meter with a reference optical signal intensity value and outputting a feedback control signal such that the measured optical signal intensity value follows the reference optical signal intensity value; And (e) an electric furnace position adjusting unit adjusting the position of the electric furnace when an abnormality occurs in the alignment state of the electric furnace according to the feedback control signal to match the central axis of the optical fiber base material with the central axis of the electric furnace; Alignment method of the optical fiber base material and the electric furnace using an optical sensor comprising a. The method of claim 8, The process of aligning the optical fiber base material and the electric furnace is an alignment method of the optical fiber base material and the electric furnace using the optical sensor, characterized in that the process is continuously made during the optical fiber base material manufacturing process.

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