Apparatus and method for manufacturing optical connector

Abstract

The purpose of the present disclosure is to provide an optical connector manufacturing device capable of forming a film of a refractive index matching material on a ferrule end surface such that the film thickness thereof becomes uniform.　The present disclosure relates to an optical connector manufacturing device that covers, with a refractive index matching material, a connection-side end surface of a ferrule provided in an optical connector detachably connecting an optical fiber, and comprises: two ferrule grasping members that grasp both side surfaces facing each other of the ferrule with the connection-side end surface of the ferrule upward; and an angle varying mechanism that changes the tilt of the connection-side end surface of the ferrule with respect to a horizontal plane by changing the positions of the two ferrule grasping members.

Description

[Technical field]

[0001] The present disclosure relates to an apparatus and method for manufacturing an optical connector that detachably connects optical fibers. [Background technology]

[0002] MT connectors and MPO connectors are used as multi-core optical connectors for connecting multiple fibers in an optical fiber cable. MT and MPO connectors use MT ferrules as the ferrules that adhesively fix and hold the optical fibers.

[0003] MT ferrules have multiple optical fiber insertion holes for adhesively fixing and aligning optical fibers, and two guide pin holes for holding or inserting guide pins for fitting MT ferrules together. The end face of the MT ferrule has a structure in which the optical fiber insertion hole is located between the two guide pin holes. MT connectors and MPO connectors that use MT ferrules have a connection structure in which the guide pin is held by the guide pin hole of one MT ferrule and the guide pin is inserted into the guide pin hole of the other MT ferrule, thereby aligning the optical fiber adhesively fixed in the optical fiber insertion hole of the MT ferrule.

[0004] In an MT connector, after the optical fiber is glued and fixed to the MT ferrule, the end face of the MT ferrule is polished at a right angle and a liquid refractive index matching material with appropriate viscosity is applied to the end face of the MT ferrule. The MT ferrules are then mated together to suppress Fresnel reflection caused by gaps between the optical fibers being connected.

[0005] The MPO connector is designed so that after the optical fiber is glued and fixed to the MT ferrule, the end face of the MT ferrule is polished at an angle, the MT ferrule is built into the plug housing, and the MT ferrule is pressed from the rear end of the MT ferrule by a spring inside the plug housing.When this MPO connector plug is inserted into the openings on both ends of the adapter, the obliquely polished end faces of the optical fibers are connected facing each other while being pressed by the spring, so Fresnel reflection can be suppressed without using a refractive index matching material.

[0006] When MT ferrules with oblique end faces come into contact with each other, the force of the spring at the rear end of the MT ferrule causes the MT ferrule to slide in a direction that causes axial misalignment of the optical fiber within the clearance range between the guide pin and the guide pin hole. To suppress connection loss due to this axial misalignment, the MT ferrules used in MPO connectors offset the position of the optical fiber hole in advance, anticipating the amount of sliding due to the force of the spring, thereby achieving a low-loss connection.

[0007] The IEC, an international standards organization, specifies the spring compression force according to the number of fibers in the MPO connector. The IEC 61754-2-1 standard for 16-fiber MPO connectors specifies a spring compression force of about 10 N, and the IEC 61754-2-2 standard for 32-fiber MPO connectors specifies a spring compression force of about 20 N.

[0008] In the future, it is expected that the spring pressure will increase in line with the increase in the number of cores in MPO connectors. However, this will require adjustments to the offset of the optical fiber holes due to the increased sliding amount of the MT ferrule during connection, as well as measures such as deformation of components due to the increased spring pressure and changes to materials to provide resistance to the increased spring pressure. This will increase the difficulty of designing and manufacturing MPO connectors, making it harder to achieve low-loss connections.

[0009] As a method for solving this problem, as shown in FIG. 1, a refractive index matching material 93, which is a resin whose refractive index matches that of quartz glass, is applied to a connection side end face 91E of an MT ferrule 91 that adhesively holds an optical fiber 92, and is hardened by irradiating the connection side end face 91E with ultraviolet light, thereby covering the optical fiber end face 92E at the connection side end face of the MT ferrule 91 with the refractive index matching material 93, except for the guide pin hole 94 (for example, see Non-Patent Document 1).

[0010] In order to realize an optical connector using the MT ferrule 91 of Non-Patent Document 1, it is necessary to form a layer of refractive index matching material 93 with a constant thickness on the connecting end face 91E of the MT ferrule 91. For example, when connecting MT ferrules 91 each having a layer of refractive index matching material 93 with a non-uniform thickness, Fresnel reflection occurs in the gap between the MT ferrules connected opposite to each other, resulting in a connection with deteriorated return loss. Even if the MT ferrules connected opposite to each other are normal MT ferrules not coated with a refractive index matching material, Fresnel reflection occurs in the same way, resulting in a connection with deteriorated return loss. [Prior art documents] [Non-patent literature]

[0011] [Non-Patent Document 1] Yoshiteru Abe, Ryo Koyama, Kazunori Katayama, "Study on multi-core optical fiber connection using solid refractive index matching material," IEICE Society Conference, B-13-17, 2021 Summary of the Invention [Problem to be solved by the invention]

[0012] Therefore, the present disclosure has been proposed in consideration of the above circumstances, and has an object to provide an apparatus capable of depositing a refractive index matching material so that the film thickness is uniform on the end face of a ferrule. [Means for solving the problem]

[0013] The apparatus according to the present disclosure comprises: An optical connector manufacturing apparatus for covering a connecting end face of a ferrule provided in an optical connector for detachably connecting an optical fiber with a refractive index matching material, comprising: two ferrule gripping members for gripping the side surfaces of the ferrule with the connection side end surface of the ferrule facing up; an angle varying mechanism that varies the positions of the two ferrule gripping members to vary the inclination of the connection side end surface of the ferrule with respect to a horizontal plane; Equipped with.

[0014] The method according to the present disclosure comprises: A method for manufacturing an optical connector, comprising covering a connecting end face of a ferrule provided in an optical connector for detachably connecting an optical fiber with a refractive index matching material, the method comprising the steps of: With the connection side end face of the ferrule facing up, the side faces of the ferrule are gripped by two ferrule gripping members; By changing the positions of the two ferrule gripping members, the connection side end face of the ferrule is made parallel to a horizontal plane; The refractive index matching material film is formed in a state in which the connection side end face of the ferrule is parallel to a horizontal plane. Effect of the Invention

[0015] The optical connector manufacturing apparatus according to the present disclosure has the advantage that a refractive index matching material can be formed on the ferrule end surface with a constant thickness. [Brief description of the drawings]

[0016] [Figure 1] This is an example of an optical connector in which the connection end face of the ferrule is covered with a refractive index matching material. [Diagram 2] 1 shows a basic configuration example of an optical connector manufacturing apparatus that covers the connection side end face of a ferrule with a refractive index matching material. [Diagram 3] 1 shows an example of the structure of two ferrule gripping members as viewed from the top end surface. [Figure 4] 13 is an explanatory diagram of a method for covering the connection side end face with a refractive index matching material using an optical connector manufacturing apparatus. [Diagram 5]1 is a schematic diagram showing a first embodiment of an optical connector manufacturing apparatus according to the present disclosure; [Figure 6] 1 is a schematic diagram showing a second embodiment of an optical connector manufacturing apparatus according to the present disclosure; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments shown below. These implementation examples are merely illustrative, and the present disclosure can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art. Note that components with the same reference numerals in this specification and drawings are assumed to indicate the same components.

[0018] (Basic configuration) An example of the basic configuration of an optical connector manufacturing apparatus according to the present disclosure is shown in Fig. 2. The optical connector manufacturing apparatus according to the present disclosure is an optical connector manufacturing apparatus that covers the connection side end face of a ferrule provided in an optical connector that detachably connects optical fibers with a refractive index matching material, and includes a ferrule holding unit 10 and a pressing unit 20. The ferrule holding unit 10 includes a fixing base 11, ferrule gripping members 12A and 12B, a guide pole insertion hole 13, and a removable spacer 14. The pressing unit 20 includes a glass substrate 21 and a guide pole 22.

[0019] The ferrule holding part 10 includes ferrule holding members 12A and 12B for holding the MT ferrule 91 with the connection side end face 91E of the MT ferrule 91 facing up, a fixing base 11 for fixing the ferrule holding members 12A and 12B, and a spacer 14 for hardening the refractive index matching material 93 to a constant film thickness. The spacer 14 is a flat plate with a constant thickness, and has a surface structure that is not bonded to the refractive index matching material 93. The pressing part 20 includes a glass substrate 21 for pressing the spacer 14 against the connection side end face 91E of the MT ferrule 91.

[0020] 2 and 3, two ferrule gripping members 12A and 12B grip the side surfaces of the MT ferrule 91. The upper end faces of the ferrule gripping members 12A and 12B are perpendicular to the surface gripping the MT ferrule 91, similar to the connection side end face 91E of the MT ferrule 91. The height of the upper end faces of the ferrule gripping members 12A and 12B is arbitrary, and may be the same height as the connection side end face 91E of the MT ferrule 91.

[0021] FIG. 4 shows an explanatory diagram of the film forming method of this embodiment. As shown in FIG. 4(a), an MT ferrule 91 is fixed in the gap (reference numeral 15 shown in FIG. 2) between the ferrule gripping members 12A and 12B, and the MT ferrule 91 is placed on the fixing table 11 with the connection side end surface 91E of the MT ferrule 91 facing up. After placing the spacer 14 on the connection side end face 91E of the MT ferrule 91, An appropriate amount of liquid refractive index matching material 93 is dropped onto the connection side end face 91 E of the MT ferrule 91 . Then, as shown in FIG. 4(b), the guide pole 22 fixed to the glass substrate 21 is inserted into the guide pole insertion hole 13 of the fixing base, and the glass substrate 21 is pressed against the connection side end face 91E of the MT ferrule 91 by its own weight, and ultraviolet light is irradiated from above. As a result, in this embodiment, a film of the refractive index matching material 93 can be formed on the connection side end face 91E of the MT ferrule 91, as shown in FIG. 4(c).

[0022] In this device configuration, if ultraviolet light can be irradiated onto the refractive index matching material 93 while the connection side end face 91E of the MT ferrule 91 and the glass substrate 21 are parallel to each other, a layer of the refractive index matching material 93 having a constant thickness can be formed on the connection side end face 91E of the MT ferrule 91. Therefore, the present disclosure makes it possible to manufacture an optical connector having a film of the refractive index matching material 93 formed thereon. The MT ferrule 91 may be used in an MT connector or an MPO connector.

[0023] (First embodiment) DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an optical connector manufacturing apparatus according to the present disclosure will be described with reference to the drawings. Fig. 5 is a schematic diagram showing a first embodiment of an optical connector manufacturing apparatus according to the present disclosure. The optical connector manufacturing apparatus of this embodiment is provided with an angle variable mechanism for changing the angle of the connection side end face 91E of the MT ferrule 91 relative to the horizontal plane, thereby keeping the upper surfaces of the ferrule gripping members 12A and 12B parallel to the glass substrate 21. In this embodiment, an example is shown in which a rotating stage 31 and stage connecting members 32A and 32B are provided as the angle variable mechanism.

[0024] The optical connector manufacturing apparatus of this embodiment is an optical connector manufacturing apparatus for forming a film on a connection side end face 91E of an MT ferrule 91 with a refractive index matching material 93. An optical fiber 92 is fixed to the MT ferrule 91 with an adhesive, and the connection side end face 91E of the MT ferrule 91 and the optical fiber end face 92E are polished. The MT ferrule 91 is fixed to the ferrule holding members 12A and 12B with the connection side end face 91E of the MT ferrule 91 facing upward.

[0025] Spacers 14 are provided on the tops of the ferrule holding members 12A and 12B to provide thickness when the refractive index matching material 93 hardens. The MT ferrule 91 can be attached and detached to the ferrule holding members 12A and 12B using screws or the like. The rotating stage 31 is fixed to the bottom of the fixed base 11. The ferrule holding members 12A and 12B are connected to the rotating stage 31 via stage connecting members 32A and 32B.

[0026] The rotating stage 31 can rotate around an axis parallel to the x-axis and an axis parallel to the y-axis shown in FIG. 5, and the ferrule gripping members 12A and 12B can also move around an axis parallel to the x-axis and an axis parallel to the y-axis. By rotating the rotating stage 31 around an axis parallel to the x-axis, the inclination of the connecting side end face 91E of the MT ferrule 91 with respect to the y-axis can be adjusted. In addition, by rotating the rotating stage 31 around an axis parallel to the y-axis, the inclination of the connecting side end face 91E of the MT ferrule 91 with respect to the x-axis can be adjusted. As a result, in this embodiment, the inclination of the connecting side end face 91E of the MT ferrule 91 with respect to the xy plane parallel to the horizontal plane can be adjusted, so that the connecting side end face 91E of the MT ferrule 91 and the lower surface of the glass substrate 21 can be made parallel to each other.

[0027] With an appropriate amount of liquid refractive index matching material 93 dropped onto the connection side end face 91E of the MT ferrule 91, the glass substrate 21 is placed over the MT ferrule 91. The surfaces of the spacer 14 and the glass substrate 21 are coated with Teflon (registered trademark), and are structured so as not to be bonded to the refractive index matching material 93 even when the refractive index matching material 93 hardens. Therefore, the refractive index matching material 93 is not bonded to the lower surface of the glass substrate 21 and the spacer 14. The glass substrate 21 is pressed against the connection side end face 91E of the MT ferrule 91 by its own weight. By irradiating the refractive index matching material 93 with ultraviolet light from above the glass substrate 21, the refractive index matching material 93 hardens and is formed into a film on the connection side end face 91E of the MT ferrule 91.

[0028] After the film is formed, the glass substrate 21 is removed, and further, the MT ferrule 91 is removed from the ferrule holding members 12A and 12B, and the film thickness of the refractive index matching material 93 formed on the connection side end face 91E of the MT ferrule 91 is measured using a laser microscope or the like. By measuring the film thickness, the parallelism between the connection side end face 91E of the MT ferrule 91 and the glass substrate 21 before curing can be evaluated.

[0029] If there is a deviation in the thickness of the refractive index matching material 93, the connection side end face 91E of the MT ferrule 91 and the glass substrate 21 are not set parallel to each other, so the rotating stage 31 is adjusted. The rotating stage 31 is operated based on the measured inclination of the film of the refractive index matching material 93 to adjust the inclination of the connection side end face 91E of the MT ferrule 91 so that the connection side end face 91E of the MT ferrule 91 and the glass substrate 21 are parallel to each other. After the inclination of the connection side end face 91E of the MT ferrule 91 is adjusted by the rotating stage 31, the refractive index matching material 93 is dropped and cured, and the film thickness is measured. These steps are repeated until a uniform film of the refractive index matching material 93 can be formed on the connection side end face 91E of the MT ferrule 91. Thus, in the first embodiment of the optical connector manufacturing apparatus of the present disclosure, the film thickness is measured after the film is formed, the inclination of the connection side end face 91E of the MT ferrule 91 is adjusted, and the film is formed again.

[0030] The optical connector manufacturing apparatus of this embodiment can make the connection side end face 91E of the MT ferrule 91 parallel to the glass substrate 21 by adjusting the positions of the ferrule holding members 12A and 12B that hold the MT ferrule 91. This allows the refractive index matching material 93 to be formed with a constant thickness on the connection side end face 91E of the MT ferrule 91 in this embodiment.

[0031] Second embodiment 6 is a schematic diagram showing a second embodiment of the optical connector manufacturing apparatus of the present disclosure. The second embodiment is provided with an angle detection unit that detects the inclination of the connection side end face 91E of the MT ferrule 91 in addition to the configuration of the first embodiment. In this embodiment, a configuration is shown in which four load sensors 33 functioning as the angle detection unit and a load sensor stage 34 fixed to the fixing base 11 and for contacting each load sensor 33 with the lower part of the MT ferrule 91 are added. By providing the four load sensors 33, this embodiment detects the distribution of the load applied to the connection side end face 91E of the MT ferrule 91.

[0032] The MT ferrule 91 held by the ferrule holding members 12A and 12B is in a state where the lower part of the MT ferrule 91 is in contact with the four load sensors 33. The four load sensors 33 are disposed near the four corners of the MT ferrule 91, for example, at positions p1 to p4 shown in Fig. 3. This makes it possible to determine whether the weight of the glass substrate 21 is evenly applied to the connection side end face 91E of the MT ferrule 91.

[0033] An appropriate amount of liquid refractive index matching material 93 is dropped onto the connection side end face 91E of the MT ferrule 91, and the glass substrate 21 is placed over the MT ferrule 91. The glass substrate 21 is pressed against the connection side end face 91E of the MT ferrule 91 by its own weight.

[0034] At this time, if the values ​​of the four load sensors 33 are the same, the weight of the glass substrate 21 is evenly applied to the connection side end face 91E of the MT ferrule 91. Therefore, when the values ​​of the four load sensors 33 are the same, while the values ​​of the four load sensors 33 are maintained in the same state, ultraviolet light is irradiated onto the refractive index matching material 93 from above the glass substrate 21 to harden the refractive index matching material 93.

[0035] On the other hand, when the values ​​of the load sensors 33 are different, the inclination of the connection side end face 91E of the MT ferrule 91 is adjusted by the rotation stage 31 so that the values ​​of the load sensors 33 become the same. After the values ​​of the load sensors 33 become the same, ultraviolet light is irradiated onto the refractive index matching material 93 from above the glass substrate 21 to harden the refractive index matching material 93.

[0036] In this embodiment, the parallelism between the glass substrate 21 and the connection side end face 91E of the MT ferrule 91 can be evaluated at the point in time when the glass substrate 21 is placed over the connection side end face 91E of the MT ferrule 91. Therefore, in this embodiment, it is possible to adjust the bias in the film thickness of the refractive index matching material 93 when it is formed on the connection side end face 91 of the MT ferrule 91 without measuring the film thickness.

[0037] In this embodiment, an example is shown in which the angle detection unit includes four load sensors 33, but the number of load sensors 33 may be any number. In addition, in this embodiment, an example is shown in which the load sensor 33 is used to detect the inclination of the connection side end face 91E of the MT ferrule 91, but the principle of the angle detection unit in this disclosure is arbitrary. For example, by using the principle of an interference fringe microscope using a white light source, the inclination of the connection side end face 91E of the MT ferrule 91 can be detected by observing the interference fringes that are generated by irradiating the connection side end face 91E of the MT ferrule 91 with a white light source.

[0038] As described above, the optical connector manufacturing apparatus according to this embodiment can adjust the connection side end face 91E of the MT ferrule 91 to be parallel to the glass substrate 21 by connecting the ferrule gripping members 12A and 12B that grip the MT ferrule 91 to the rotation stage 31 that can control the inclination of the connection side end face 91E of the MT ferrule 91. Furthermore, the optical connector manufacturing apparatus according to the present disclosure is configured to have a load sensor 33 that is brought into contact with the MT ferrule 91 located below the MT ferrule 91.

[0039] The present disclosure is not limited to MT ferrules, but can be applied to any ferrule provided in an optical connector that detachably connects optical fibers. [Industrial Applicability]

[0040] With the optical connector manufacturing apparatus of the present disclosure, there is no need to increase the spring force pressing the ferrule from the rear end, which was previously necessary when increasing the number of connection cores in a multi-core optical connector, and it is possible to ensure the uniformity of the film thickness of the refractive index matching material, which was a challenge in the manufacture of multi-core optical connectors in which a film of refractive index matching material is formed on the end face of an MT ferrule, thereby improving the manufacturing yield of multi-core optical connectors and being beneficial for reducing the cost of multi-core connectors. [Explanation of symbols]

[0041] 10: Ferrule holding part 11:Fixed stand 12A, 12B: Ferrule holding member 13: Guide pole insertion hole 14: Spacer 20: Clamp 21: Glass substrate 22: Guide pole 31: Rotating stage 31 32A, 32B: Stage connecting member 91:MT ferrule 91E: Connection side end face 92: Optical fiber 92E: Optical fiber end face 93: Refractive index matching material 94: Guide pin hole

Claims

1. An optical connector manufacturing apparatus for covering a connecting end face of a ferrule provided in an optical connector for detachably connecting an optical fiber with a refractive index matching material, comprising: two ferrule gripping members for gripping side surfaces of the ferrule with the connection side end surface of the ferrule facing up; an angle varying mechanism that varies the positions of the two ferrule gripping members to vary the inclination of the connection side end surface of the ferrule with respect to a horizontal plane; a spacer disposed on the two ferrule gripping members so as to protrude beyond the connection side end faces of the ferrules, the spacer having a constant thickness corresponding to a thickness of the refractive index matching material and a surface structure that is not bonded to the refractive index matching material; An optical connector manufacturing apparatus comprising:

2. an angle detection unit for detecting an inclination of the connection side end face of the ferrule, The angle varying mechanism changes the inclination of the connection side end face of the ferrule based on the inclination detected by the angle detection unit.

2. The optical connector manufacturing apparatus according to claim 1.

3. the angle detection unit includes a load sensor that detects a distribution of a load applied to a connection side end face of the ferrule.

3. The optical connector manufacturing apparatus according to claim 2.

4. The two ferrule gripping members are fixed to a fixed base, and the angle varying mechanism is a rotation stage fixed to the bottom of the fixed table; a stage connecting member that connects the rotation stage and the ferrule gripping member; Equipped with By rotating the rotation stage, an inclination of the connection side end surface of the ferrule with respect to a horizontal plane is adjusted.

4. An optical connector manufacturing apparatus according to claim 1.

5. a pressing part that presses the liquid refractive index matching material dropped on the connection side end surface of the ferrule from above, a region of the pressing portion covering the connection side end surface of the ferrule is transparent to ultraviolet light; The refractive index matching material is cured by irradiating the refractive index matching material with ultraviolet light through the pressing portion.

5. An optical connector manufacturing apparatus according to claim 1.

6. The two ferrule gripping members are fixed to a fixing base in which a guide pole insertion hole is formed, the guide pole insertion hole extending in a direction different from a direction parallel to the connection side end face of the ferrule when the ferrule is gripped by the ferrule gripping members; a guide pole extending in the different directions and inserted into the guide pole insertion hole, and a pressing part pressing from above the liquid refractive index matching material dripped onto the connection side end face of the ferrule; 2. The optical connector manufacturing apparatus according to claim 1.

7. A method for manufacturing an optical connector, comprising covering a connecting end face of a ferrule provided in an optical connector for detachably connecting an optical fiber with a refractive index matching material, the method comprising the steps of: With the connection side end face of the ferrule facing up, the side faces of the ferrule are gripped by two ferrule gripping members; By changing the positions of the two ferrule gripping members, the connection side end face of the ferrule is made parallel to a horizontal plane; a spacer that is disposed on the ferrule gripping member so as to protrude beyond the connection side end face of the ferrule while the connection side end face of the ferrule is in a state where the connection side end face of the ferrule is parallel to a horizontal plane, the spacer having a constant thickness corresponding to a thickness of the refractive index matching material and a surface structure that is not bonded to the refractive index matching material, and a film of the refractive index matching material is formed between the spacer and the spacer. Optical connector manufacturing method.

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