Welding machine and welding method
By rotating multi-core optical fibers and observing them from different directions using two microscopes, and combining this with calculation formulas to calculate the loss, the problem of decreased calculation accuracy caused by overlapping fiber cores in multi-core optical fibers was solved, and high-precision loss estimation was achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SUMITOMO ELECTRIC INDUSTRIES LTD
- Filing Date
- 2024-12-10
- Publication Date
- 2026-07-10
AI Technical Summary
In the process of connecting multi-core optical fibers, existing technologies struggle to calculate estimated loss with high precision, especially when multiple fiber cores overlap, as it is impossible to observe them simultaneously using two microscopes, leading to a decrease in calculation accuracy.
A rotating mechanism is used to rotate the multi-core optical fiber, and the fiber is observed from different directions using two microscopes to obtain image data. Combined with parameters such as axis deviation, angular deviation, and mode field diameter, the estimated loss is calculated using the Marcuse formula.
It enables high-precision loss calculation for multi-core optical fibers, improving the accuracy of fiber core position detection and loss calculation.
Smart Images
Figure CN122374686A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to a welding machine and a welding method.
[0002] This application claims priority based on Japanese Patent Application No. 2023-223130, dated December 28, 2023, and incorporates all the contents described in the said Japanese Patent Application. Background Technology
[0003] Patent Document 1 describes a method for estimating the connection loss of optical fibers. In this method, the power of a single-mode optical fiber with four cores fused together is measured using power monitoring. The method measures the axial deviation before and after heating and fusion. The estimated loss is calculated based on the difference between these axial deviations. Non-Patent Document 1 describes a method for estimating the connection loss of an optical fiber using the Marcuse loss formula based on the fiber's shape.
[0004] Patent document 2 describes a fusion splicer. The fusion splicer includes: a fiber optic holder for holding an optical fiber; a rotation mechanism for rotating the optical fiber; a bending section for bending the optical fiber; a light source for shining light from the side of the optical fiber; and a power supply unit for supplying power to the light source. The bending section and the light source are positioned on the fiber optic holder, near the tip of the optical fiber, or on any one of the fiber optic holder and the rotation mechanism.
[0005] Patent document 3 describes a method for fusion splicing optical fibers. In this method, the optical fibers to be spliced are arranged at predetermined intervals, preheated by gas discharge, and then formally heated. The shape of the fiber core after fusion splicing is photographed and image processed. Based on the data obtained as a result of image processing, the connection loss is estimated using FD-BPM (Differential Beam Propagation). In FD-BPM, the data is compared with data from a pre-created database.
[0006] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 1-196531 Patent Document 2: International Publication No. 2022 / 244843 Patent Document 3: Japanese Patent Application Publication No. 9-138318 Non-patent literature Non-patent literature 1: D. Marcuse, “Loss Analysis of Single-Mode Fiber Splices”, The Bell System Technical Journal, Vol. 56, No. 5, pp. 703-718, 1977. Summary of the Invention
[0007] The fusion splicer disclosed herein fuses a first multi-core optical fiber and a second multi-core optical fiber together, wherein the first multi-core optical fiber has a plurality of first cores exposed at a first end face, and the second multi-core optical fiber has a plurality of second cores exposed at a second end face. The fusion splicer includes: a rotation mechanism for rotating the fused first and second multi-core optical fibers; a first microscope for observing the first and second multi-core optical fibers by receiving light emitted from a first light source along a first direction to the first and second multi-core optical fibers; a second microscope for observing the first and second multi-core optical fibers by receiving light emitted from a second light source along a second direction intersecting the first direction to the first and second multi-core optical fibers; and the ability to calculate an estimated loss based on the images of the first and second multi-core optical fibers acquired by the first and second microscopes. Attached Figure Description
[0008] Figure 1 This is a diagram showing the schematic configuration of a welding machine according to an embodiment.
[0009] Figure 2 This is a schematic diagram showing the first and second multi-core optical fibers.
[0010] Figure 3 This is a diagram showing the observation mechanism of the multi-core optical fiber in the fusion splicer of the embodiment.
[0011] Figure 4 This is a diagram showing an image of a multi-core optical fiber obtained through a microscope using a fusion splicer according to the embodiment.
[0012] Figure 5 It is a diagram used to illustrate axial deviation and angular deviation.
[0013] Figure 6 It means Figure 3 Images of the light source, multi-core optical fiber, and microscope in the observation mechanism.
[0014] Figure 7 It means in Figure 3 The diagram shows the state of the multi-core optical fiber rotation and microscope movement in the observation mechanism.
[0015] Figure 8 This is a flowchart illustrating an example of the steps in a welding method for implementing an embodiment. Detailed Implementation
[0016] As a method for calculating the estimated loss of optical fibers, one known approach involves observing the fiber from different directions using two microscopes, determining the core positions, and then calculating the estimated loss. However, in the case of multi-core fibers, the multiple cores sometimes overlap when observed under a microscope. In such cases, it is sometimes impossible to observe multiple cores simultaneously using two microscopes. When simultaneous observation of multiple cores using two microscopes is not possible, the accuracy of the estimated loss calculation for multi-core fibers may decrease. Therefore, there is room for improvement in the accuracy of the estimated loss calculation for multi-core fibers.
[0017] The purpose of this disclosure is to provide a fusion splicer and a fusion splicing method capable of calculating the estimated loss of multi-core optical fibers with high accuracy.
[0018] According to this disclosure, the estimated loss of multi-core optical fibers can be calculated with high precision.
[0019] [Description of embodiments of the invention] First, embodiments of the welding machine and welding method disclosed herein will be described.
[0020] (1) A fusion splicer according to one embodiment fusion splices a first multi-core optical fiber and a second multi-core optical fiber together, wherein the first multi-core optical fiber has a plurality of first cores exposed at a first end face, and the second multi-core optical fiber has a plurality of second cores exposed at a second end face. The fusion splicer includes: a rotation mechanism for rotating the fused first and second multi-core optical fibers; a first microscope for observing the first and second multi-core optical fibers by receiving light emitted from a first light source along a first direction to the first and second multi-core optical fibers; a second microscope for observing the first and second multi-core optical fibers by receiving light emitted from a second light source along a second direction intersecting the first direction to the first and second multi-core optical fibers; and calculating an estimated loss based on the images of the first and second multi-core optical fibers acquired by the first microscope and the images of the first and second multi-core optical fibers acquired by the second microscope. The "image" includes not only data configured as an image, but also a collection of data such as position information, brightness information, or color information that form the basis of the image.
[0021] (6) A fusion splicing method according to one embodiment splices a first multi-core optical fiber to a second multi-core optical fiber, wherein the first multi-core optical fiber has a plurality of first cores exposed at a first end face, and the second multi-core optical fiber has a plurality of second cores exposed at a second end face. The fusion splicing method includes the following steps: rotating the first multi-core optical fiber and the second multi-core optical fiber after fusion splicing; observing the first multi-core optical fiber and the second multi-core optical fiber by receiving light emitted to the first multi-core optical fiber and the second multi-core optical fiber along a first direction; observing the first multi-core optical fiber and the second multi-core optical fiber by receiving light emitted to the first multi-core optical fiber and the second multi-core optical fiber along a second direction intersecting the first direction; and calculating an estimated loss based on the images of the first multi-core optical fiber and the second multi-core optical fiber obtained by the first microscope and the images of the first multi-core optical fiber and the second multi-core optical fiber obtained by the second microscope.
[0022] The fusion splicer and fusion splicing method include a rotation mechanism, a first microscope, a second microscope, and a computing unit. The first microscope receives light emitted in a first direction to observe the fused first and second multi-core optical fibers, while the second microscope receives light emitted in a second direction to observe the fused first and second multi-core optical fibers. When observing the first and second multi-core optical fibers using the first and second microscopes, the rotation mechanism can rotate the first and second multi-core optical fibers. Therefore, observation of the first and second multi-core optical fibers can be performed at each of the following positions: positions where the first and second fiber cores can be detected when observed from the first microscope and positions where the first and second fiber cores can be detected when observed from the second microscope. Therefore, the computing unit can calculate the estimated loss with high precision based on the images of the first and second multi-core optical fibers acquired by the first and second microscopes.
[0023] (2) In (1) above, the rotating mechanism may also rotate the first multi-core fiber and the second multi-core fiber until either the first microscope or the second microscope can observe the plurality of first cores and the plurality of second cores. In this case, the estimated loss can be calculated with higher accuracy based on the images of the first multi-core fiber and the second multi-core fiber.
[0024] (3) In (1) above, the rotating mechanism may also rotate the first multi-core fiber and the second multi-core fiber until both the first microscope and the second microscope can observe a first fiber core and a second fiber core. In this case, the estimated loss can be calculated with higher accuracy based on the images of the first multi-core fiber and the second multi-core fiber.
[0025] (4) In any of (1) to (3) above, the first microscope may acquire an image of the first or second multi-core fiber when its focal position is deviated from a plane perpendicular to the optical axis of the first microscope and containing the central axis of the first or second multi-core fiber. Alternatively, the second microscope may acquire an image of the first or second multi-core fiber when its focal position is deviated from a plane perpendicular to the optical axis of the second microscope and containing the central axis of the first or second multi-core fiber. In this case, the accuracy of determining the position of the first or second fiber core in the acquired image is improved.
[0026] (5) In any of (1) to (4) above, the calculation unit may calculate the estimated loss based on the axial deviation, the angular deviation, the mode field diameter of the first fiber core and the mode field diameter of the second fiber core, wherein the axial deviation is the deviation of the axis of the second fiber core relative to the axis of the first fiber core, and the angular deviation is the deviation of the extension direction of the second fiber core on the second end face relative to the extension direction of the first fiber core on the first end face.
[0027] [Details of the embodiments disclosed herein] Specific examples of the welding machine and welding method of the embodiments will be described. In the description of the drawings, the same or equivalent elements are labeled with the same reference numerals, and repeated descriptions are omitted where appropriate. For ease of understanding, some parts are sometimes simplified or exaggerated in the drawings, but the size ratios are not limited to those shown in the drawings.
[0028] Reference Figure 1 The configuration of the welding machine in this embodiment will be described. Figure 1 This is a diagram used to illustrate the general outline of the welding machine 1 in this embodiment. (See diagram below.) Figure 1 As shown, fusion splicer 1 fuses a pair of optical fibers F together. Fusion splicer 1 includes: an optical fiber retainer 10 with a V-groove 11; and a rotation mechanism 20 that rotates the optical fiber retainer 10. The axes of the pair of optical fibers F are aligned. "Axis" refers to the centerline of the optical fiber that passes through its center and extends along its direction of extension.
[0029] The fiber optic retainers 10 and the rotation mechanism 20 are arranged along the axial direction that extends as the axis of the fiber F. When an XYZ three-dimensional orthogonal coordinate system is established, and the axis of the fiber F is set as the Z-axis, the axial direction of the fiber F is the Z-axis direction. The fusion splicer 1 includes: a pair of fiber optic retainers 10 arranged along the Z-axis direction that extends as the respective directions of a pair of fibers F; and a pair of rotation mechanisms 20 arranged along the Z-axis direction.
[0030] The optical fiber F to be spliced is positioned in the V-groove 11 of each fiber holder 10. As an example, the fiber holder 10 is made of metal. The fiber holder 10 holds, for example, the covered portion of the optical fiber F. The fiber holder 10 holds the optical fiber F with its end face F1 protruding in the Z-axis direction. The rotation mechanism 20, when viewed from the fiber holder 10, is positioned on the side opposite to the end face F1 of the optical fiber F.
[0031] A pair of discharge electrodes 2 are disposed opposite each other at the end faces F1 of a pair of optical fibers F. The pair of discharge electrodes 2 are disposed opposite each other in a direction intersecting the optical fibers F (e.g., the X-axis direction). The optical fiber holder 10 has, for example, a platform 12 with a V-groove 11 extending along the Z-axis direction for mounting the optical fibers F; and a cover 13 disposed on the platform 12. The platform 12 and the cover 13 are arranged, for example, along the Y-axis direction, which intersects both the X-axis and Z-axis directions.
[0032] A pair of discharge electrodes 2 fuse the end faces F1 of a pair of optical fibers F together through discharge. The fusion splicer 1 includes a control unit 3 that controls each part of the fusion splicer 1. The control unit 3 controls the discharge current and discharge time of the discharge electrodes 2, thereby performing fusion splicing under fusion conditions suitable for the type of optical fiber F. In the fusion splicer 1, the control unit 3 performs alignment of the pair of optical fibers F.
[0033] The control unit 3 adjusts the position of each fiber F in the X-axis and Y-axis directions, and aligns the pair of fibers F so that they are aligned in a straight line along the Z-axis. The control unit 3 performs centering in the X-axis, Y-axis, and Z-axis directions of the pair of fibers F. The control unit 3 controls the rotation mechanism 20 to rotate the fiber F around its axis (which is the same as the Z-axis in the figure), thereby performing centering in the θ-direction.
[0034] Fiber F is a multi-core fiber. A multi-core fiber is an fiber in which the positions of the core, cladding, and markings in the θ direction are aligned with the multi-core fiber of the object being connected. Figure 2 An example of an optical fiber F being fused in fusion splicer 1 is shown. For example... Figure 2 As shown, optical fiber F includes a first multi-core optical fiber F11 and a second multi-core optical fiber F21. The fusion splicer 1 splices the first multi-core optical fiber F11 to the second multi-core optical fiber F21.
[0035] The first multi-core optical fiber F11 has multiple first cores F12 exposed on the first end face F13, and the second multi-core optical fiber F21 has multiple second cores F22 exposed on the second end face F23. Hereinafter, unless there is a need to distinguish between the first multi-core optical fiber F11 and the second multi-core optical fiber F21, they will sometimes be referred to as fiber F.
[0036] The fusion splicer 1 is equipped with an observation mechanism for observing a pair of optical fibers F. Figure 3 This is a diagram showing an observation mechanism 30 as an example of an observation mechanism for a welding machine 1. The observation mechanism 30 has a light source 31 and a microscope 32. The light source 31 includes a first light source 31b and a second light source 31c, and the microscope 32 includes a first microscope 32b and a second microscope 32c.
[0037] The first light source 31b is, for example, a light-emitting element such as a light-emitting diode. As an example, the first light source 31b emits light L as red light. The first microscope 32b includes, for example, an observation lens and an imaging element. For example, the first microscope 32b is a CCD camera (Charge-Coupled Device Camera) or a CMOS camera (Complementary Metal Oxide Semiconductor Camera), etc.
[0038] For example, the position of the first microscope 32b is set to be variable. The observation results obtained through the first microscope 32b are acquired, for example, as brightness information of light L. The brightness information of light L acquired through the first microscope 32b is output to the control unit 3. For example, the function and configuration of the second light source 31c are the same as those of the first light source 31b, and the function and configuration of the second microscope 32c are the same as those of the first microscope 32b.
[0039] A first light source 31b and a first microscope 32b are separated by an optical fiber F and arranged along a first direction D1. A second light source 31c and a second microscope 32c are separated by an optical fiber F and arranged along a second direction D2 that intersects the first direction D1. The angle between the first direction D1 and the second direction D2 is, for example, greater than 0° and less than 180°, or greater than or equal to 60° and less than or equal to 120° (90° is an example). The first light source 31b emits light L along the first direction D1 into the first multi-core optical fiber F11 and the second multi-core optical fiber F21. The second light source 31c emits light L along the second direction D2 into the first multi-core optical fiber F11 and the second multi-core optical fiber F21.
[0040] The first microscope 32b observes the first multi-core fiber F11 and the second multi-core fiber F21 by receiving light L emitted from the first light source 31b to the first multi-core fiber F11 and the second multi-core fiber F21. The second microscope 32c observes the first multi-core fiber F11 and the second multi-core fiber F21 by receiving light L emitted from the second light source 31c to the first multi-core fiber F11 and the second multi-core fiber F21. The aforementioned rotating mechanism 20 rotates the first multi-core fiber F11 and the second multi-core fiber F21 until both the first microscope 32b and the second microscope 32c can observe the multiple first fiber cores F12 and the second fiber cores F22.
[0041] The first microscope 32b acquires images of the first multi-core optical fiber F11 and the second multi-core optical fiber F21. For example, the first microscope 32b receives light L passing through the first multi-core optical fiber F11 and the second multi-core optical fiber F21 to obtain brightness information of the first multi-core optical fiber F11 and the second multi-core optical fiber F21.
[0042] Figure 4 An example of a lateral view image obtained through the first microscope 32b is shown. For example... Figure 4 As shown, the side-view image reveals the outer diameter B of the cladding of the optical fiber F and the region W where the light is focused by the cladding of the optical fiber F. The image acquisition performed by the second microscope 32c is conducted in the same manner as the image acquisition performed by the first microscope 32b.
[0043] like Figure 3 As shown, the control unit 3 includes, for example, a calculation unit 33 for calculating the estimated loss of the optical fiber F, and a drive unit 34 for moving the first microscope 32b and the second microscope 32c. The estimated loss of the optical fiber F represents, for example, an estimated value of the connection loss generated between the first multi-core optical fiber F11 and the second multi-core optical fiber F21. The calculation unit 33 calculates the estimated loss based on the images of the first multi-core optical fiber F11 and the second multi-core optical fiber F21 acquired by the first microscope 32b and the second microscope 32c.
[0044] For example, the first microscope 32b and the second microscope 32c acquire images of the fused first multi-core fiber F11 and the second multi-core fiber F21, respectively. If an image of the fused portion including the first multi-core fiber F11 and the second multi-core fiber F21 near the central portion is acquired, images of both the first multi-core fiber F11 and the second multi-core fiber F21 can be acquired simultaneously using a single microscope. At this time, the calculation unit 33 calculates the estimated loss based on the images of the fused first multi-core fiber F11 and the second multi-core fiber F21.
[0045] like Figure 5As shown, the calculation unit 33 calculates the estimated loss for each fiber core from the image M1 acquired by the first microscope 32b and the image M2 acquired by the second microscope 32c, based on the axial deviation d and angular deviation θ of the first multi-core fiber F11 and the second multi-core fiber F21, the mode field diameter of the first fiber core F12, and the mode field diameter of the second fiber core F22. The axial deviation d represents the deviation of the axis of the second fiber core F22 relative to the axis of the first fiber core F12. The angular deviation θ is the deviation of the extension direction of the second fiber core F22 on the second end face F23 relative to the extension direction of the first fiber core F12 on the first end face F13.
[0046] For example, the calculation unit 33 calculates the estimated loss of the first multi-core fiber F11 and the second multi-core fiber F21 based on the axial deviation d, the angular deviation θ, and the mode field diameter (MFD) mismatch. In this case, the calculation unit 33 calculates the estimated loss, for example, using the Marcuse formula described in Non-Patent Document 1 above. The mode field diameter mismatch, for example, represents the difference between the mode field diameter of the first multi-core fiber F11 and the mode field diameter of the second multi-core fiber F21.
[0047] use Figure 6 and Figure 7 The acquisition of the image of fiber F and the calculation of the estimated loss are explained in more detail below. Hereinafter, unless there is a need to distinguish between the first fiber core F12 and the second fiber core F22, they will sometimes be referred to simply as fiber core F2. For example, as... Figure 6 As shown, when the two fiber cores F2 overlap in the optical path of the light L from the second light source 31c, it is sometimes difficult to observe the two fiber cores F2 simultaneously using either the first microscope 32b or the second microscope 32c. "The two fiber cores overlap in the optical path" means, for example, that at least a portion of the two fiber cores are aligned along the optical path of the light from the light source.
[0048] like Figure 7 As shown, the rotation mechanism 20 rotates the optical fiber F so that the positions of the two fiber cores F2 can be observed by the first microscope 32b and the second microscope 32c, respectively. It should be noted that the rotation mechanism 20 can also be used without rotating the optical fiber F to the first microscope 32b and the second microscope 32c to observe the positions of the two fiber cores F2 simultaneously. Alternatively, the rotation mechanism 20 can be used to rotate the optical fiber F so that the first microscope 32b can observe the rotational position of the two fiber cores F2, and the second microscope 32c can observe each of the rotational positions of the two fiber cores F2.
[0049] Alternatively, the rotation mechanism 20 can rotate the fiber F to each of the following positions: the first microscope 32b can observe the rotational position of the first fiber core F2, the first microscope 32b can observe the rotational position of the second fiber core F2, the second microscope 32c can observe the rotational position of the first fiber core F2, and the second microscope 32c can observe the rotational position of the second fiber core F2. The rotation mechanism 20 can rotate the fiber F at each determined angle, or it can rotate the fiber F until the fiber core F2 becomes the most easily visible angle. For example, in Figure 7 In the example, the rotating mechanism 20 rotates the optical fiber F by an angle A in the θ direction until the two fiber cores F2 do not overlap in the optical path of the light L from the first light source 31b, and the two fiber cores F2 do not overlap in the optical path of the light L from the second light source 31c.
[0050] The value of angle A can be stored in advance. Furthermore, the value of angle A can change each time an image is acquired by the first microscope 32b and the second microscope 32c. Angle A is, for example, greater than or equal to 40° and less than or equal to 50°. However, the value of angle A is not particularly limited. As described above, by rotating the optical fiber F, both the first microscope 32b and the second microscope 32c can observe the two mutually separated fiber cores F2.
[0051] It should be noted that the position for observing fiber core F2 does not necessarily have to be a position where the two fiber cores F2 do not overlap completely. The position for observing fiber core F2 only needs to be such that the rotational position of one fiber core F2 can be detected. By repeatedly acquiring images, confirming detection, and changing the rotational position, images of the first microscope 32b and the second microscope 32c can eventually be acquired for all or a specific number of fiber cores of the first fiber core F12 and the second fiber core F22. "A specific number of fiber cores" refers, for example, to the number of fiber cores required to calculate the worst or average value of the estimated loss of all or a portion of the fiber cores. "A specific number of fiber cores" is, for example, "more than half of the total number of fiber cores included in a multi-core optical fiber." Or, "a specific number of fiber cores" is "the fiber core with the worst straightness near the splice among all the fiber cores." It can also be set as "inspecting approximately half of the total number of fiber cores included in a multi-core optical fiber using the first microscope 32b, and inspecting the remaining fiber cores using the second microscope 32c."
[0052] The drive unit 34 moves the first microscope 32b and the second microscope 32c, for example, by outputting a drive signal to each of them. The drive unit 34 moves the first microscope 32b along a first direction D1 and the second microscope 32c along a second direction D2. For example, the drive unit 34 moves the first microscope 32b and the second microscope 32c in directions closer to or further away from the optical fiber F, respectively. The drive unit 34 moves the first microscope 32b and the second microscope 32c respectively in such a way that the focal position is aligned on a plane perpendicular to the optical axes of the first microscope 32b and the second microscope 32c and includes the central axis of the optical fiber F. In this state, the first microscope 32b and the second microscope 32c acquire images respectively.
[0053] At this time, sometimes the fiber core F2 cannot be detected in the acquired image, which may affect the calculation of the estimated loss performed by the calculation unit 33. Therefore, the drive unit 34 moves the first microscope 32b and the second microscope 32c respectively in such a way that the focal position is offset from the plane perpendicular to the optical axis of the microscope and the plane containing the central axis of the fiber F.
[0054] For example, the drive unit 34 moves the first microscope 32b and the second microscope 32c away from the fiber F by N μm (N is a real number) from a position where the focal position is aligned on a plane perpendicular to the optical axis of the microscope and encompassing the central axis of the fiber F. The value of N can be stored in advance. The value of N can also change each time an image is acquired by the first microscope 32b and the second microscope 32c. The drive unit 34 can also move the first microscope 32b and the second microscope 32c closer to the fiber F. N is represented by a positive value when moving away and by a negative value when moving closer.
[0055] If the outer diameter of the cladding of fiber F is set to B μm (refer to...) Figure 4 For example, the absolute value of N can be greater than 0 and less than or equal to B, or greater than 0 and less than or equal to 65. The value of N can also be the value when the in-situ ratio, calculated based on the region W where the light is focused by the cladding of the fiber F, is greater than or equal to 20% and less than or equal to 80%. The in-situ ratio is calculated as 100 × W / B. The first microscope 32b and the second microscope 32c acquire images of the fiber F when the focal position is deviated from the plane perpendicular to the optical axis of the microscope and encompassing the central axis of the fiber F. This allows for a clearer acquisition of the image of the fiber core F2.
[0056] Reference Figure 8 The welding method of this embodiment will be described. Figure 8This is a flowchart illustrating an example of the steps in the fusion splicing method of the embodiment. Hereinafter, an example of a method for performing fusion splicing and calculating estimated loss using fusion splicer 1 will be described. First, the end faces F1 of a pair of optical fibers F are positioned opposite each other. The first end face F13 of the first multi-core optical fiber F11 is positioned opposite the second end face F23 of the second multi-core optical fiber F21.
[0057] Then, the rotating mechanism 20 rotates at least one of the first multi-core optical fibers F11 and F12 in the θ direction, thereby performing rotational alignment. During rotational alignment, the positions of the plurality of first cores F12 of the first multi-core optical fiber F11 in the θ direction are aligned with the positions of the plurality of second cores F22 of the second multi-core optical fiber F21 in the θ direction. Then, the first end face F13 of the first multi-core optical fiber F11 is fused to the second end face F23 of the second multi-core optical fiber F21 through the discharge electrode 2 (fusion process, step S1).
[0058] Next, the first multi-core fiber F11 and the second multi-core fiber F21 are rotated (rotation process, step S2). As described above, the rotation mechanism 20 rotates the first multi-core fiber F11 and the second multi-core fiber F21 until both fiber cores F2 can be observed by both the first microscope 32b and the second microscope 32c.
[0059] After rotating the first multi-core optical fiber F11 and the second multi-core optical fiber F21, the first microscope 32b and the second microscope 32c observe the first multi-core optical fiber F11 and the second multi-core optical fiber F21 respectively and acquire images (the process of observation by the first microscope, the process of observation by the second microscope, step S3).
[0060] Images of the first multi-core optical fiber F11 and the second multi-core optical fiber F21 acquired by the first microscope 32b and images of the first multi-core optical fiber F11 and the second multi-core optical fiber F21 acquired by the second microscope 32c are output to the control unit 3. For example, the control unit 3 determines whether the first fiber core F12 and the second fiber core F22 cannot be detected in the images output to the control unit 3 (step S4, the process of determining whether they cannot be detected). Whether they cannot be detected can be determined, for example, based on the brightness information in the images.
[0061] If it is determined that both the first fiber core F12 and the second fiber core F22 can be detected, the control unit 3 proceeds to step S8. On the other hand, if it is determined that either the first fiber core F12 or the second fiber core F22 cannot be detected, the control unit 3 defocuses the first microscope 32b and the second microscope 32c (defocusing process, step S5). At this time, the drive unit 34 moves the first microscope 32b or the second microscope 32c to a position offset from the plane perpendicular to the optical axis of the first microscope 32b or the second microscope 32c and containing the central axis of the fiber F. Then, the first microscope 32b and the second microscope 32c observe the first multi-core fiber F11 and the second multi-core fiber F21 to acquire images (observation process of the first microscope, observation process of the second microscope, step S6). Afterwards, the process proceeds to step S7 to determine whether the first fiber core F12 and the second fiber core F22 cannot be detected. If either the first fiber core F12 or the second fiber core F22 cannot be detected, the process proceeds to step S5. These processes (steps) are repeated as many times as necessary until it is determined that both the first fiber core F12 and the second fiber core F22 can be detected. Then, when it is determined that both the first fiber core F12 and the second fiber core F22 can be detected, proceed to step S8.
[0062] In step S8, the calculation unit 33 calculates the estimated loss (the step of calculating the estimated loss) based on the images of the first multi-core fiber F11 and the second multi-core fiber F21 obtained by the first microscope 32b and the images of the first multi-core fiber F11 and the second multi-core fiber F21 obtained by the second microscope 32c. For example, the calculation unit 33 calculates the estimated loss based on the axial deviation d and angular deviation θ of the first multi-core fiber F11 and the second multi-core fiber F21, the mode field diameter of the first fiber core F12, and the mode field diameter of the second fiber core F22. After that, a series of steps are completed.
[0063] The effects obtained from the fusion splicer 1 and fusion splicing method of this embodiment will be explained. The fusion splicer 1 and fusion splicing method of this embodiment include a rotation mechanism 20, a first microscope 32b, a second microscope 32c, and a calculation unit 33. The first microscope 32b receives light L emitted along a first direction D1 to observe the fused first multi-core optical fiber F11 and the second multi-core optical fiber F21, and the second microscope 32c receives light L emitted along a second direction D2 to observe the fused first multi-core optical fiber F11 and the second multi-core optical fiber F21. When observing the first multi-core optical fiber F11 and the second multi-core optical fiber F21 through the first microscope 32b and the second microscope 32c, the rotation mechanism 20 can rotate the first multi-core optical fiber F11 and the second multi-core optical fiber F21.
[0064] Therefore, the first multi-core fiber F11 and the second multi-core fiber F21 can be observed when the fiber is rotated to a position where the first fiber core F12 and the second fiber core F22 can be detected when observed from the first microscope 32b, and the first fiber core F12 and the second fiber core F22 can be detected when observed from the second microscope 32c. Therefore, the calculation unit 33 can calculate the estimated loss with high precision based on the images of the first multi-core fiber F11 and the second multi-core fiber F21 obtained from the first microscope 32b and the second microscope 32c.
[0065] As described above, the rotating mechanism 20 can also rotate the first multi-core fiber F11 and the second multi-core fiber F21 until either the first microscope 32b or the second microscope 32c can observe the plurality of first fiber cores F12 and the plurality of second fiber cores F22. In this case, the estimated loss can be calculated with higher accuracy based on the images of the first multi-core fiber F11 and the second multi-core fiber F21.
[0066] As described above, the rotating mechanism 20 can also rotate the first multi-core fiber F11 and the second multi-core fiber F21 until both the first microscope 32b and the second microscope 32c can observe a first fiber core F12 and a second fiber core F22. In this case, the estimated loss can be calculated with higher accuracy based on the images of the first multi-core fiber F11 and the second multi-core fiber F21.
[0067] As described above, the first microscope 32b may acquire an image of the first multi-core fiber F11 or the second multi-core fiber F21 when its focal position is deviated from a plane perpendicular to the optical axis of the first microscope 32b and containing the central axis of the first multi-core fiber F11 or the second multi-core fiber F21. Alternatively, the second microscope 32c may acquire an image of the first multi-core fiber F11 or the second multi-core fiber F21 when its focal position is deviated from a plane perpendicular to the optical axis of the second microscope 32c and containing the central axis of the first multi-core fiber F11 or the second multi-core fiber F21. In this case, the images of the acquired first fiber core F12 and the second fiber core F22 can be acquired more clearly. As a result, the accuracy of determining the position of the first or second fiber core in the acquired image is improved.
[0068] As described above, the calculation unit 33 can also calculate the estimated loss based on the axial deviation d, the angular deviation θ, the mode field diameter of the first fiber core F12, and the mode field diameter of the second fiber core F22. Here, the axial deviation d is the deviation of the axis of the second fiber core F22 relative to the axis of the first fiber core F12, and the angular deviation θ is the deviation of the extension direction of the second fiber core F22 on the second end face F23 relative to the extension direction of the first fiber core F12 on the first end face F13. In this case, the estimated loss can be calculated with higher accuracy.
[0069] The embodiments of the welding machine and welding method disclosed herein have been described above. However, the present invention is not limited to the embodiments described above. That is, those skilled in the art will readily recognize that the present invention can be modified and altered in various ways within the scope of the spirit of the claims. The configuration of each part of the welding machine and the steps of the welding method can be appropriately modified within the scope of the above spirit. That is, the configuration, shape, size, quantity, material and configuration of each part of the welding machine, as well as the content and sequence of the steps of the welding method, are not limited to the embodiments described above and can be appropriately modified.
[0070] For example, in the above embodiment, an example of defocusing was described. Defocusing involves moving the first microscope 32b or the second microscope 32c to a position offset from the focal point on a plane perpendicular to the optical axis of the first microscope 32b or the second microscope 32c and containing the central axis of the optical fiber F. However, defocusing may not be performed. In this case, the time spent on fusion splicing can be further reduced.
[0071] In the above embodiment, an example of fusing a first multi-core optical fiber F11 having two first cores F12 to a second multi-core optical fiber F21 having two second cores F22 has been described. However, the number of cores in the first and second multi-core optical fibers can also be greater than or equal to 3, and can be appropriately changed.
[0072] Explanation of reference numerals in the attached figures: 1: Fusion welding machine; 2: Discharge electrode; 3: Control Unit; 10: Fiber optic hold; 11: V-groove; 12: Taiwan; 13: Cover; 20: Rotating mechanism; 30: Observational institutions; 31: Light source; 31b: First light source; 31c: Second light source; 32: Microscope; 32b: First microscope; 32c: Second microscope; 33: Computing Department; 34: Drive unit; A: Angle; F: Optical fiber; F1: End face; F2: Fiber core; F11: First multi-core optical fiber; F12: First fiber core; F13: First end face; F21: Second multi-core optical fiber; F22: Second fiber core; F23: Second end face; L: light; M1, M2: Images.
Claims
1. A fusion splicer for splicing a first multi-core optical fiber and a second multi-core optical fiber together, wherein, The first multi-core optical fiber has a plurality of first cores exposed at a first end face, and the second multi-core optical fiber has a plurality of second cores exposed at a second end face. The fusion splicer comprises: A rotating mechanism that causes the first multi-core optical fiber and the second multi-core optical fiber, which are fused together, to rotate. The first microscope observes the first multi-core optical fiber and the second multi-core optical fiber by receiving light emitted from the first light source along the first direction to the first multi-core optical fiber and the second multi-core optical fiber; The second microscope observes the first and second multi-core optical fibers by receiving light emitted from the second light source along a second direction that intersects with the first direction. as well as The computing unit calculates the estimated loss based on the images of the first multi-core optical fiber and the second multi-core optical fiber obtained by the first microscope and the images of the first multi-core optical fiber and the second multi-core optical fiber obtained by the second microscope.
2. The welding machine according to claim 1, wherein, The rotating mechanism rotates the first multi-core optical fiber and the second multi-core optical fiber until either the first microscope or the second microscope can observe the plurality of the first fiber cores and the plurality of the second fiber cores.
3. The welding machine according to claim 1, wherein, The rotating mechanism rotates the first multi-core optical fiber and the second multi-core optical fiber until both the first microscope and the second microscope can observe one of the first fiber cores and one of the second fiber cores.
4. The welding machine according to claim 1 or 2, wherein, The first microscope acquires an image of the first multi-core fiber or the second multi-core fiber when its focal position is deviated from a plane perpendicular to the optical axis of the first microscope and containing the central axis of the first multi-core fiber or the second multi-core fiber; or, The second microscope acquires an image of the first multi-core fiber or the second multi-core fiber when the focal position is deviated from a plane perpendicular to the optical axis of the second microscope and containing the central axis of the first multi-core fiber or the second multi-core fiber.
5. The welding machine according to claim 1 or 2, wherein, The calculation unit calculates the estimated loss based on the axial deviation, the angular deviation, the mode field diameter of the first fiber core, and the mode field diameter of the second fiber core. The axial deviation is the deviation of the axis of the second fiber core relative to the axis of the first fiber core, and the angular deviation is the deviation of the extension direction of the second fiber core on the second end face relative to the extension direction of the first fiber core on the first end face.
6. A fusion splicing method for splicing a first multi-core optical fiber to a second multi-core optical fiber, wherein, The first multi-core optical fiber has a plurality of first cores exposed at a first end face, and the second multi-core optical fiber has a plurality of second cores exposed at a second end face. The fusion splicing method includes the following steps: Rotate the first multi-core optical fiber and the second multi-core optical fiber after they are fused together. The first microscope observes the first multi-core optical fiber and the second multi-core optical fiber by receiving light emitted along the first direction to the first multi-core optical fiber and the second multi-core optical fiber; The second microscope observes the first multi-core optical fiber and the second multi-core optical fiber by receiving light emitted into the first multi-core optical fiber and the second multi-core optical fiber along a second direction that intersects with the first direction; as well as The estimated loss is calculated based on the images of the first multi-core optical fiber and the second multi-core optical fiber obtained by the first microscope and the images of the first multi-core optical fiber and the second multi-core optical fiber obtained by the second microscope.