Combiner and Light Source

Abstract

To obtain a combiner and a light source device that are new and improved and make it possible to switch a shape of a spot of a laser beam and a power density distribution on a surface of an object more easily or variably than the prior art in laser processing.SOLUTION: A combiner, for example, includes: a plurality of input optical fibers each having a core and a cladding; one output optical fiber having a plurality of cores and at least one cladding; and a bundle part that is formed by bundling end parts of the plurality of input optical fibers and comes in contact with the output optical fiber. The respective cores of the input optical fibers in the bundle part are optically connected to any one of the plurality of cores of the output optical fiber, and the respective cores of the output optical fiber are also optically connected to any core of the plurality of input optical fibers in the bundle part.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a combiner and a light source device. [Background technology]

[0002] BACKGROUND ART Conventionally, laser processing devices are known that irradiate a target object with laser light to perform processing such as welding or cutting (for example, Non-Patent Document 1). [Prior art documents] [Non-patent literature]

[0003] [Patent Document 1] Patent Publication No. 2021-159931 Summary of the Invention [Problem to be solved by the invention]

[0004] In this type of laser processing, it would be beneficial if the shape of the laser light spot on the surface of the object and the power density distribution could be changed more easily or in more diverse ways.

[0005] Therefore, one object of the present invention is to provide a new and improved combiner and light source device that enables easier or more diverse switching of the shape and power density distribution of the laser light spot on the surface of an object, for example, in laser processing. [Means for solving the problem]

[0006] A combiner of the present invention has, for example, a plurality of input optical fibers each having a core and a clad, one output optical fiber having a plurality of cores and at least one clad, and a bundle portion in which the ends of the plurality of input optical fibers are bundled and in contact with the output optical fiber, and each core of the input optical fibers in the bundle portion is optically connected to one of the plurality of cores of the output optical fiber, and each core of the output optical fiber is optically connected to one of the cores of the plurality of input optical fibers in the bundle portion.

[0007] In the combiner, the bundle portion may have a tapered fiber bundle structure.

[0008] In the combiner, the bundle may have cores of the plurality of input optical fibers arranged in an annular shape in a cross section intersecting a central axis of the bundle.

[0009] In the combiner, the output optical fiber may have a cylindrical core as the core, and the cylindrical core may be optically connected to the cores of the multiple input optical fibers arranged in the annular shape in the bundle portion.

[0010] In the combiner, the cores of the plurality of annularly arranged input optical fibers may be arranged at approximately equal intervals around the central axis.

[0011] In the combiner, the bundle portion may have a plurality of core groups each including cores of the plurality of input optical fibers arranged in the annular shape, and the plurality of core groups may be arranged approximately concentrically in the cross section.

[0012] In the combiner, the output optical fiber may have, as the multiple cores, multiple cylindrical cores arranged approximately concentrically in a cross section intersecting with the central axis of the output optical fiber, and the combiner may optically connect the cores of the input optical fiber to different cylindrical cores for each core group.

[0013] In the combiner, the multiple core groups include a first core group and a second core group surrounding the first core group in the cross section, and the number of cores of the input optical fiber included in the second core group may be greater than the number of cores of the input optical fiber included in the first core group.

[0014] In the combiner, in the cross section, the centers of the cores of the input optical fibers included in the second core group may be offset with respect to a virtual line passing through the central axis and the centers of the cores of the input optical fibers included in the first core group.

[0015] In the combiner, in the bundle portion, the cores of the multiple input optical fibers may have a first core and multiple second cores arranged in a ring shape around the first core in the cross section, and the diameter of the first core may be larger than the diameter of the second core.

[0016] In the combiner, in the bundle portion, the cores of the multiple input optical fibers may have multiple first cores and multiple third cores arranged in a ring shape around the multiple first cores in the cross section, and the multiple first cores may be optically connected to one of the multiple cores of the input optical fiber.

[0017] In the combiner, the plurality of cores in the output optical fiber may include a plurality of cores arranged in an annular shape in a cross section intersecting with a longitudinal direction of the output optical fiber.

[0018] The light source device of the present invention includes, for example, the combiner, a plurality of light sources optically connected to each of the input optical fibers and outputting laser light, and a delivery optical fiber optically connected to the output optical fiber.

[0019] In the light source device, the delivery optical fiber may be optically connected to an optical head of a laser processing device, and transmit the laser beams output from the plurality of light sources to the optical head. [Effects of the Invention]

[0020] According to the present invention, a new and improved combiner and light source device can be provided that, for example, enables the shape and power density distribution of the laser light spot on the surface of an object to be more easily or variably switched during laser processing. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is an exemplary schematic diagram of a laser processing apparatus including a light source device and a combiner according to a first embodiment. [Figure 2] FIG. 2 is an exemplary schematic cross-sectional view of the combiner of the first embodiment. [Figure 3] FIG. 3 is an exemplary schematic cross-sectional view of a bundle portion of the combiner of the first embodiment. [Figure 4] FIG. 4 is an exemplary schematic cross-sectional view of an output optical fiber of the combiner of the first embodiment. [Figure 5] FIG. 5 is an explanatory diagram showing an example of the power density of the laser light in each core of the delivery optical fiber of the first embodiment. [Figure 6] FIG. 6 is an explanatory diagram showing an example of the power density of the laser light in each core of the delivery optical fiber of the first embodiment. [Figure 7] FIG. 7 is an explanatory diagram showing an example of the power density of the laser light in each core of the delivery optical fiber of the first embodiment. [Figure 8] FIG. 8 is an explanatory diagram showing an example of the power density of the laser light in each core of the delivery optical fiber of the first embodiment. [Figure 9] FIG. 9 is an exemplary schematic cross-sectional view of the output optical fiber of the combiner of the first embodiment, illustrating an example of the power density of the laser light in each core of the input optical fiber of the combiner. [Figure 10] FIG. 10 is an exemplary schematic cross-sectional view of a bundle portion of a combiner according to the second embodiment. [Figure 11]FIG. 11 is an exemplary schematic cross-sectional view of a bundle portion of a combiner according to the third embodiment. [Figure 12] FIG. 12 is an exemplary schematic cross-sectional view of a bundle portion of a combiner according to the fourth embodiment. [Figure 13] FIG. 13 is an exemplary schematic diagram of a light source device according to the fifth embodiment. [Figure 14] FIG. 14 is an exemplary schematic cross-sectional view of an output optical fiber of the combiner of the fifth embodiment. [Figure 15] FIG. 15 is an exemplary schematic cross-sectional view of an output optical fiber of the combiner of the sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] Exemplary embodiments of the present invention are disclosed below. The configurations of the embodiments described below, as well as the actions and results (effects) brought about by the configurations, are merely examples. The present invention can also be realized by configurations other than those disclosed in the following embodiments. Furthermore, according to the present invention, it is possible to obtain at least one of the various effects (including derivative effects) obtained by the configurations.

[0023] The following embodiments have similar configurations. Therefore, according to the configurations of each embodiment, similar actions and effects based on the similar configurations can be obtained. Furthermore, in the following, similar configurations are given similar reference numerals, and duplicated explanations may be omitted.

[0024] In this specification, ordinal numbers are given for convenience to distinguish between parts, portions, etc., and do not indicate priority or order.

[0025] In addition, hatching has been omitted from some cross-sectional views for ease of understanding.

[0026] [First embodiment] [Laser device configuration] FIG. 1 is a schematic diagram of a laser processing apparatus 1 including a light source device 100 and a combiner 10 according to an embodiment. The light source device 100 includes a plurality of light sources 30, a plurality of optical fibers 110, a combiner 10, one optical fiber 120, and a connector 121 that optically connects the optical fiber 120 to an optical head 20. That is, the combiner 10 is included in the light source device 100. The laser processing apparatus 1 also includes the light source device 100, the optical head 20, a sensor 40, and a control device 50. The laser processing apparatus 1 performs laser processing, such as welding or cutting, of the object W by irradiating a laser beam from the optical head 20 toward a surface Wa of the object W. The optical fiber 120 is an example of a delivery optical fiber.

[0027] Each light source 30 is a laser device that outputs laser light. For example, the light source 30 is a single-mode fiber laser with an output of 1.5 kW. The light source 30 may include a light-emitting element group in which multiple laser elements are connected in series, may be a multi-mode fiber laser, or may be another laser device.

[0028] Each optical fiber 110 is optically connected to a light source 30 and transmits laser light output from the light source 30. The optical fiber 110 is, for example, a single-mode optical fiber, but may also be a multi-mode optical fiber. Note that the optical fiber 110 may include multiple optical fibers connected in series.

[0029] The optical fiber 120 is optically connected to the optical head 20 via a connector 121. The optical fiber 120 is a so-called multi-core optical fiber having multiple cores. Note that the optical fiber 120 may have multiple optical fibers connected in series.

[0030] The combiner 10 also optically connects a plurality of optical fibers 110 to one optical fiber 120 .

[0031] 2 is a cross-sectional view taken along the central axes Ax1 and Ax2 of the combiner 10. The combiner 10 has a plurality of optical fibers 11, one optical fiber 12, and a bundle 13 in which end portions 11d of the plurality of optical fibers 11 are bundled. Here, the central axis Ax1 is the central axis of the bundle 13, and the central axis Ax2 is the central axis of the optical fiber 12. The deviation between the central axis Ax1 and the central axis Ax2 is substantially zero.

[0032] Each optical fiber 11 has a core 11a, a cladding 11b that surrounds the core 11a and has a lower refractive index than the core 11a, and a coating 11c that surrounds the cladding 11b. The core 11a and the cladding 11b are each made of glass such as silica-based glass. The coating 11c is made of a synthetic resin material, for example. The coating 11c is removed at an end 11d. Each optical fiber 11 is optically connected to an optical fiber 110. The optical fiber 11 has substantially the same cross-sectional shape as the optical fiber 110. The optical fiber 11 is an example of an input optical fiber. It can also be said that the optical fiber 11 is a part of the optical fiber 110.

[0033] The optical fiber 12 is a so-called multi-core optical fiber having multiple cores 12a and at least one cladding 12b having a refractive index lower than that of the cores 12a. The cores 12a and the cladding 12b are each made of glass such as silica-based glass. The optical fiber 12 is optically connected to an optical fiber 120. The optical fiber 12 has substantially the same cross-sectional shape as the optical fiber 120. The optical fiber 12 is an example of an output optical fiber. It can also be said that the optical fiber 12 is a part of the optical fiber 120.

[0034] The bundle portion 13 has a tapered portion 13a and an extending portion 13b, and has a so-called tapered fiber bundle structure.

[0035] The tapered portion 13a gradually becomes thinner toward the end face 12c of the optical fiber 12 while maintaining the similarity of the arrangement and shape of the cores 11a in the cross section. That is, in the tapered portion 13a, as it moves toward the Z1 direction, each core 11a gradually becomes thinner and the distance between the multiple cores 11a gradually becomes narrower. Here, the Z1 direction is the direction toward the optical fiber 12 along the central axis Ax1 of the bundle 13.

[0036] In the extension portion 13b, the cores 11a and claddings 11b extend substantially parallel to each other while maintaining the similarity in arrangement and shape at the end of the tapered portion 13a in the Z1 direction. An end face 13c of the extension portion 13b, i.e., the end face 13c of the combiner 10, is connected to an end face 12c of the optical fiber 12 by fusion splicing or the like. The extension portion 13b may be omitted. In this case, the end of the tapered portion 13a becomes the end of the bundle portion 13.

[0037] 3 is a cross-sectional view of a boundary portion B (splicing position, see FIG. 2) between the bundle 13 and the optical fibers 12, as viewed in the Z2 direction. Here, the Z2 direction is the direction toward the bundle 13 along the central axis Ax2 of the optical fibers 12.

[0038] 3, the bundle portion 13 has a plurality of cores 11a and one clad 11b. Note that, instead of one clad 11b, the bundle portion 13 may have a plurality of clads 11b that surround the cores 11a and are adjacent to each other.

[0039] The cores 11a include a core 11a0 positioned to overlap the central axis Ax1 and a plurality of cores 11a arranged in a ring shape at intervals around the core 11a0 in a cross section intersecting the central axis Ax1. The cores 11a arranged in a ring shape are arranged at approximately equal intervals in the circumferential direction so as to overlap an imaginary circle c1 centered on the central axis Ax1. Hereinafter, the cores 11a overlapping the imaginary circle c1 will be referred to as belonging to core group G1. In this embodiment, as an example, the number of cores 11a belonging to core group G1 is 6, and the total number of cores 11a in the bundle portion 13 is 7, but this is not limited to this.

[0040] FIG. 4 is a cross-sectional view of a boundary portion B between the optical fiber 12 and the bundle portion 13 as viewed in the Z1 direction.

[0041] As shown in FIG. 4, the optical fiber 12 has a plurality of cores 12a and a plurality of claddings 12b.

[0042] The cores 12a include a core 12a0 positioned to overlap the central axis Ax2 and a cylindrical core 12a1 surrounding the core 12a0 at a distance. Here, "cylindrical" means that the core 12a0 has an annular shape in a cross section intersecting with the central axis Ax2 and extends axially with a predetermined thickness in the radial direction.

[0043] The claddings 12b include two cylindrical claddings 12b1 and 12b2. The cladding 12b1 is interposed between the outer peripheral surface of the core 12a0 and the inner peripheral surface of the core 12a1, and the cladding 12b2 surrounds and forms the outer peripheral surface of the core 12a1. Each of the claddings 12b (12b1 and 12b2) is in contact with at least one core 12a. The claddings 12b are arranged to fill the entire cross section of the optical fiber 12 intersecting the central axis Ax2, except for the cores 12a.

[0044] The end face 13c of the bundle 13 and the end face 12c of the optical fiber 12 are connected by fusion splicing or the like. Here, as shown in FIG. 4 , at the end face 12c of the optical fiber 12 facing the end face 13c of the bundle 13, the cores 12a are arranged so as to face one of the cores 11a, and the cores 11a are arranged so as to face one of the cores 12a. In this embodiment, with the arrangement shown in FIG. 4 , the core 12a0 of the optical fiber 12 faces and is optically connected to the core 11a0 of the bundle 13, and the core 12a1 of the optical fiber 12 faces and is optically connected to the multiple cores 11a belonging to the core group G1 of the bundle 13. In this way, in the combiner 10, the core 11a of each of the optical fibers 11 in the bundle 13 is optically connected to one of the multiple cores 12a of the optical fiber 12, and the core 12a of the optical fiber 12 is optically connected to one of the cores 11a of the multiple optical fibers 11 in the bundle 13.

[0045] The cores 11a of the multiple optical fibers 11 are each optically connected to the light source 30 via the core of the optical fiber 110 (see Figure 1), and the multiple cores 12a of the optical fiber 12 are each optically connected to the optical head 20 via the core of the optical fiber 120.

[0046] With the above-described configuration, the light source 30 is optically connected to the optical head 20 via the optical fiber 110, the combiner 10, the optical fiber 120, and the connector 121, respectively.

[0047] As shown in FIG. 1, the optical head 20 irradiates the surface Wa of the object W with laser light from multiple light sources 30 input via optical fibers 120. A spot of laser light is formed on the surface Wa. The shape of the spot depends on the arrangement and shape of the cores 12a in the cross section of the optical fibers 12 in the combiner 10, the distribution of the input positions of the laser light to the cores 12a, and the like. In this embodiment, a double spot is formed on the surface Wa, including a central point-like spot and a ring-shaped spot surrounding the central spot with a gap therebetween.

[0048] Furthermore, the spot of the laser light moves on the surface Wa due to changes in the output direction of the laser light from the optical head 20 and the relative movement between the optical head 20 and the object W. In other words, the spot of the laser light is swept on the surface Wa.

[0049] The sensor 40 is, for example, a radiation thermometer or an infrared thermography camera that detects a physical quantity such as the temperature of a molten pool formed on the object W by irradiation with laser light. The sensor 40 may also be a camera that detects the shape of the object W, a specific position, a marker, or an object such as spatter scattered from the molten pool.

[0050] The control device 50 includes a computer having, for example, a controller such as a CPU, a main memory such as a RAM or ROM, and an auxiliary memory such as a HDD or SSD. The control device 50 operates according to a program and can switch the light source 30 on and off, or change the output power by changing the drive current of the light source 30, based on predetermined processing procedures stored in advance and the detection results of the sensor 40. The control device 50 can control the operation of at least one light source 30. The control device 50 may also control the operation of multiple light sources 30 individually, or may control the operation of multiple light sources 30 collectively.

[0051] In addition, based on the detection results of the sensor 40, the control device 50 can control the operation of the galvanometer scanner provided in the optical head 20 so as to change the sweep speed of the laser light spot on the surface Wa of the object W, or control the operation of the drive mechanism that moves the optical head 20 and the object W relatively.

[0052] 5 to 8 are explanatory diagrams showing the power density of the laser light transmitted through each core 120a near the end of the optical fiber 120 close to the optical head 20 when the control device 50 switches the operating state of the light source 30. The optical fiber 120 has substantially the same cross-sectional shape as the optical fiber 12 of the combiner 10. The core 120a0 (120a) is optically connected to the core 12a0, and the core 120a1 (120a) is optically connected to the core 12a1. At the boundary between the optical fiber 12 and the optical fiber 120, the cladding 120b1 (120b) faces the cladding 12b1, and the cladding 120b2 (120b) faces the cladding 12b2. In addition, in FIGS. 5 to 8, each core 120a is provided with a dot pattern, and the higher the dot density in the dot pattern, the higher the power density of the laser light.

[0053] 5, the power density in core 120a0 is higher than the power density in core 120a1. In this case, in the double spot of laser light formed on surface Wa, the power density in the central point-like spot is higher than the power density in the surrounding annular spot. This state can be achieved, for example, by setting the output powers of the multiple light sources 30 optically connected to core 120a1 to be approximately the same, and setting the output power of the light source 30 optically connected to core 120a0 to be higher than the output power of each light source 30 optically connected to core 120a1.

[0054] 6, the power density in the core 120a0 is lower than the power density in the core 120a1. In this case, in the double spot of laser light formed on the surface Wa, the power density in the central point-like spot is lower than the power density in the surrounding annular spot. This state can be achieved, for example, by setting the output powers of the multiple light sources 30 optically connected to the core 120a1 to be approximately the same, and setting the output power of the light source 30 optically connected to the core 120a0 lower than the output power of each light source 30 optically connected to the core 120a1.

[0055] 7, the power density in core 120a0 and the power density in core 120a1 are substantially the same, and both are set to relatively high power densities. In this case, in the double spot of laser light formed on surface Wa, the power density is relatively high in both the central point-like spot and the surrounding annular spot. This state can be achieved, for example, by setting the output power of light source 30 optically connected to core 120a0 and each light source 30 optically connected to core 120a1 to be relatively high and the same.

[0056] 8, the power density in core 120a0 and the power density in core 120a1 are substantially the same, and both are set to relatively low power densities. In this case, in the double spot of laser light formed on surface Wa, the power density is relatively low in both the central point-like spot and the surrounding annular spot. This state can be achieved, for example, by setting the output power of light source 30 optically connected to core 120a0 and each light source 30 optically connected to core 120a1 to be relatively low and the same.

[0057] 9 is a cross-sectional view of the boundary portion B (see FIG. 2) of the optical fiber 12 with the bundle portion 13 as viewed in the Z1 direction, and is an explanatory diagram showing the power density of laser light in each core 11a in the bundle portion 13 when the output power from each light source 30 is changed from that in FIG. 4. In FIG. 9, laser light is transmitted through the cores 11a to which the dot pattern is applied, and laser light is not transmitted through the cores 11a to which the dot pattern is not applied. That is, in the case of FIG. 9, only the light source 30 optically connected to the central core 11a0 and the light source 30 optically connected to one core 11a among the multiple cores 11a belonging to the surrounding core group G1 output laser light, and the light sources 30 optically connected to the other cores 11a do not output laser light. In this case, the core 120a1 of the optical fiber 120 transmits laser light with a lower power density than the core 120a0. On the surface Wa, the spot of the laser light transmitted through the core 120a0 has a point-like shape, while the spot of the laser light transmitted through the core 120a1 will have at least one of various shapes such as a point or a ring depending on specifications such as the length and transmission loss of the core 120a1.

[0058] As described above, in this embodiment, laser light from the multiple light sources 30 is transmitted to the optical head 20 via the multiple cores 12a of the optical fiber 12 (output optical fiber) of the combiner 10 and the multiple cores 120a of the optical fiber 120 (delivery optical fiber), and is then irradiated from the optical head 20 toward the surface Wa of the object W. Therefore, by switching the light sources 30 on and off or by changing the drive current of the light sources 30 to change the output power, the shape of the laser light spot on the surface Wa of the object W can be changed. That is, according to this embodiment, by selecting the light sources 30 to be operated and variably setting the output power of each light source 30, it is possible to form laser light spots in an extremely large number of patterns on the surface Wa.

[0059] Note that switching on and off of the light sources 30 and changing the output power of the light sources 30 may be performed manually for each light source 30, rather than by the control device 50. Furthermore, the power density pattern in each core 12a, i.e., the output power pattern of the light sources 30 optically connected to each core 12a, is not limited to those exemplified in Figures 5 to 9, and can be changed in various ways. Furthermore, the light sources 30 do not need to be optically connected to all the cores 12a, and the light sources 30 may be optically connected to only some of the multiple cores 12a.

[0060] The laser processing apparatus 1 may also be configured to include a member (not shown, hereinafter referred to as a rotating member) that is fixed to the optical fiber 12 and supported rotatably relative to the body of the optical head 20, for example, in the connector 121, and that rotates the spot of laser light on the surface Wa by rotating the rotating member relative to the body of the optical head 20. In this case, the rotating member and the optical head 20 may be configured to rotate relative to each other by the operation of an electric actuator such as a motor, or may be configured to rotate relative to each other by manual operation. Note that by ensuring a predetermined length of the optical fiber 12, twisting of the rotating member relative to the body of the optical head 20 can be absorbed by the twisting of the optical fiber 12, preventing any effect on the configurations of the combiner 10, the optical fiber 11, and the light source 30.

[0061] [Second embodiment] 10 is a cross-sectional view of a boundary portion B (see FIG. 2) between the bundle portion 13A of the combiner 10A of the second embodiment and the optical fiber 12A, as viewed in the Z2 direction. As will be clear from comparing FIG. 10 with FIG. 3, in this embodiment, the number of cores 11a belonging to the core group G1 is three, which is fewer than in the first embodiment. In addition, the total number of cores 11a in the bundle portion 13A is four. Note that the numbers of optical fibers 11 (cores 11a) and light sources 30 are not limited to seven as in the first embodiment or four as in this embodiment, and can be set arbitrarily.

[0062] Further, the optical fiber 12A may have the same cross-section (end face) as the bundle portion 13A shown in FIG. 10. In this case, the optical fiber 12A has a plurality of cores 12a and one cladding 12b. At the boundary portion B where the end face 13c of the bundle portion 13A and the end face 12c of the optical fiber 12 face and are connected, the core 11a and the core 12a face and are optically connected, and the cladding 11b and the cladding 12b face and are optically connected. Even with such a configuration, the same effects as those of the first embodiment can be obtained.

[0063] [Third Embodiment] FIG. 11 is a cross-sectional view of the boundary portion B (see FIG. 2) between the optical fiber 12B and the bundle portion 13B of the combiner 10B according to the third embodiment, viewed in the Z2 direction. As shown in FIG. 11, in the bundle portion 13B of the present embodiment, a core group G2 including a plurality of cores 11a is formed so as to surround the core group G1. The cores 11a included in the core group G2 are arranged so as to overlap a virtual circle c2 that is concentric with the virtual circle c1 and has a diameter larger than that of the virtual circle c1 in a cross-section intersecting the central axis Ax1. That is, the plurality of core groups G1 and G2 are arranged in a substantially concentric circular shape. Also, in the core group G2, the cores 11a are arranged at substantially equal intervals around the central axis Ax1. The core group G1 is an example of a first core group, and the core group G2 is an example of a second core group.

[0064] The number of cores 11a belonging to the core group G2 is larger than the number of cores 11a belonging to the core group G1. Here, in the present embodiment, the diameter of the virtual circle c2 is twice the diameter of the virtual circle c1, and the number of cores 11a belonging to the core group G2 is twice the number of cores 11a belonging to the core group G1. Therefore, in the core group G1 and the core group G2, the intervals in the circumferential direction between the cores 11a adjacent to each other in the circumferential direction can be set to be substantially the same. The total number of cores 11a in the bundle portion 13B is 19.

[0065] 11, in a cross section intersecting the central axis Ax1, the centers of the cores 11a belonging to core group G2 are shifted in the circumferential direction with respect to a virtual line VL passing through the central axis Ax1 and the centers of the cores 11a belonging to core group G1. In other words, the cores 11a belonging to core group G1 and the cores 11a belonging to core group G2 are arranged so as not to line up in the radial direction of the central axis Ax1. This arrangement reduces the variation in the distance between the cores 11a in the cross section intersecting the central axis Ax1, allowing the multiple cores 11a to be arranged more dispersedly, and ultimately makes it possible to more uniform the power density of the laser light spot on the surface Wa.

[0066] 11, the optical fiber 12B has a plurality of cylindrical cores 12a (12a1, 12a2) arranged substantially concentrically about the central axis Ax2 in a cross section intersecting the central axis Ax2. The core 12a2 surrounds the core 12a1. The core 12a1 faces the plurality of cores 11a belonging to the core group G1 and is optically connected to the plurality of cores 11a. The core 12a2 faces the plurality of cores 11a belonging to the core group G2 and is optically connected to the plurality of cores 11a. Here, as described above, the number of cores 11a belonging to the core group G2 is greater than the number of cores 11a belonging to the core group G1. Therefore, the number of cores 11a optically connected to core 12a1, and therefore the number of light sources 30 that can be optically connected to core 12a1, is greater than the number of cores 11a optically connected to core 12a2, and therefore the number of light sources 30 that can be optically connected to core 12a2.

[0067] According to the present embodiment described above, laser light from a larger number of light sources 30 can be irradiated onto the object W, and therefore laser light spots can be formed in an even larger number of patterns on the surface Wa. Furthermore, since the cores 11a can be more evenly arranged on the end surface 13c of the bundle portion 13B, there is an effect that laser light spots with less variation and more uniform power density can also be formed on the surface Wa.

[0068] [Fourth embodiment] FIG. 12 is a cross-sectional view of a boundary portion B (see FIG. 2) between the bundle portion 13C of the combiner 10C of the fourth embodiment and the optical fibers, as viewed in the Z2 direction. As shown in FIG. 12, in this embodiment, a core group G3 including a plurality of cores 11a is formed to surround the core groups G1 and G2. The cores 11a included in the core group G3 are arranged so as to overlap with a virtual circle c3 that is concentric with the virtual circles c1 and c2 and has a larger diameter than the virtual circles c1 and c2 in a cross section intersecting with the central axis Ax1. That is, the multiple core groups G1, G2, and G3 are arranged approximately concentrically. In the core group G3, the cores 11a are also arranged at approximately equal intervals around the central axis Ax1. The diameter of the virtual circle c3 is three times the diameter of the virtual circle c1, and the number of cores 11a belonging to the core group G2 is three times the number of cores 11a belonging to the core group G1. The total number of cores 11a in the bundle 13C is 37. The core group G3 is an example of a second core group, and the core groups G1 and G2 are examples of first core groups corresponding to the core group G3.

[0069] The arrangement of the cores 11a in this embodiment has the same characteristics as the arrangement of the cores 11a in the third embodiment. Therefore, this embodiment also provides the same effects as the third embodiment. The number of cores 11a is not limited to the numbers disclosed in the above embodiments. That is, the laser processing apparatus 1 can be provided with a combiner including a bundle portion having various numbers of cores 11a.

[0070] [Fifth embodiment] FIG. 13 is a schematic diagram of a light source device 100D as part of a laser processing device 1D of the fifth embodiment, and FIG. 14 is a cross-sectional view of a boundary portion B (see FIG. 2) between the combiner 10D and the bundle of optical fibers 12D as viewed in the Z1 direction.

[0071] 13, in this embodiment, a light source device 100D includes multiple light sources 30, 30D, optical fibers 110, 110D, and 120, and combiners 10D and 10D1. The multiple light sources 30D (30) are optically connected to the combiner 10D via the optical fiber 110, the combiner 10D1, and the optical fiber 110D. Furthermore, multiple light sources 30 other than the light source 30D are optically connected to the combiner 10D via the optical fiber 110. The combiner 10D1 has a configuration similar to that of the combiner 10A of the second embodiment.

[0072] As shown in FIG. 14, the combiner 10D has a configuration similar to that of the combiner 10 of the first embodiment. In the combiner 10D, the core 11a0 (11a) of the optical fiber 110D is optically connected to a central core 12a0 of the optical fiber 12D, and the core 11a belonging to the core group G1 of the optical fiber 110D is optically connected to a cylindrical core 12a1. However, in the combiner 10D of this embodiment, the diameter of the central core 11a0 is larger than the diameters of the surrounding cores 11a. Furthermore, in the optical fiber 12D, the diameter of the central core 12a0 is larger than the radial thickness of the cylindrical core 12a1. In this case, the core 11a0 is an example of a first core, and the core 11a belonging to the core group G1 is an example of a second core.

[0073] According to this configuration, a spot having a higher power density at the center can be more reliably formed on the surface Wa of the object W.

[0074] [Sixth embodiment] FIG. 15 is a cross-sectional view of a boundary portion B (see FIG. 2) between a combiner 10E of the sixth embodiment and a bundle of optical fibers 12E, as viewed in the Z1 direction.

[0075] 15, in this embodiment, multiple cores 11a0 located approximately in the center of a bundle provided at the end 11d of multiple optical fibers 110 are optically connected to one core 12a0 of the optical fiber 12. The optical fiber 12E has a configuration similar to that of the optical fiber 12D of the fifth embodiment. That is, this embodiment can be said to have a configuration in which the combiner 10D1 is removed from the configuration of the fifth embodiment. In this case, the core 11a0 is an example of a first core, and the core 11a belonging to the core group G1 is an example of a third core.

[0076] This embodiment also provides the same effects as the fifth embodiment.

[0077] While the embodiments of the present invention have been described above, they are merely examples and are not intended to limit the scope of the invention. The above embodiments can be implemented in various other forms, and various omissions, substitutions, combinations, and modifications can be made without departing from the spirit of the invention. Furthermore, the specifications of each configuration, shape, and the like (structure, type, direction, model, size, length, width, thickness, height, number, arrangement, position, material, etc.) can be modified as appropriate.

[0078] For example, in the bundle or the output optical fiber, multiple cores may be grouped together and arranged to be in contact with each other at a position away from the central axis. Also, the cross-sectional shape of the cores of the output optical fiber and the delivery optical fiber may be a shape other than a circle or annulus, such as an ellipse. [Explanation of symbols]

[0079] 1,1D...Laser processing equipment 10, 10A~10E, 10D1...Combiner 11...Optical fiber (input optical fiber) 11a...Core (second core, third core) 11a0...Core (first core) 11b...Clad 11c...Coated 11d...end 12, 12A, 12B, 12D, 12E...Optical fiber (output optical fiber) 12a, 12a0, 12a1, 12a2... Core 12b, 12b1, 12b2...Clad 12c...end face 13,13A~13C…Bundle part 13a...Tapered section 13b…Nobube 13c...end face 20...Optical head 30,30D…Light source 40...Sensor 50...Control device 100,100D…Light source device 110,110D...optical fiber 120...Optical fiber (delivery optical fiber) 120a, 120a0, 120a1...core 120b, 120b1, 120b2...clad 121...Connector c1, c2, c3...virtual circles Ax1…center axis Ax2…center axis B...boundary part G1...Core Group (First Core Group) G2...Core Group (Second Core Group, First Core Group) G3...Core Group (Second Core Group) VL...Virtual line W...Object Wa...surface Z1,Z2…direction

Claims

1. a plurality of input optical fibers, each having an input core and an input cladding; an output optical fiber having a plurality of output cores and at least one output cladding; a bundle portion in which the ends of the plurality of input optical fibers are bundled and contact the output optical fiber; and The input cores in the bundle are optically connected to any of the output cores, each of the output cores is optically connected to one of the input cores in the bundle; In the bundle portion, a first core group is configured in which the plurality of input cores are annularly arranged at approximately equal intervals in the circumferential direction around a central axis of the bundle portion, and a second core group is annularly arranged in which the plurality of input cores are annularly arranged at approximately equal intervals in the circumferential direction around the central axis so as to surround the first core group at intervals, the number of the input cores included in the second core group is greater than the number of the input cores included in the first core group; a combiner, in a cross section intersecting the central axis at a position of the bundle portion in contact with the output optical fiber, a center of each of the input cores included in the second core group is shifted in the circumferential direction with respect to an imaginary line passing through the central axis and the center of the input core included in the first core group that is located closest to the input core.

2. The combiner of claim 1 , wherein the bundle portion has a tapered fiber bundle structure.

3. the output optical fiber has, as the output core, a first cylindrical core centered on the central axis, and a second cylindrical core centered on the central axis and surrounding the first cylindrical core with a gap therebetween, the input cores belonging to the first core group are optically connected to the first cylindrical core, The combiner according to claim 1 or 2, wherein the plurality of input cores belonging to the second core group are optically connected to the second cylindrical core.

4. In the bundle, the plurality of input cores include one first input core surrounded by a plurality of input cores belonging to the first core group, The combiner according to any one of claims 1 to 3, wherein the diameter of the first input core is larger than the diameters of the input cores belonging to the first core group.

5. In the bundle, the plurality of input cores include a plurality of second input cores surrounded by a plurality of input cores belonging to the first core group, 4. The combiner according to claim 1, wherein the second input cores are optically connected to one of the output cores.

6. A combiner according to any one of claims 1 to 5, wherein in the output optical fiber, the plurality of output cores have a plurality of output cores arranged in a ring shape in a cross section intersecting with the longitudinal direction of the output optical fiber.

7. A combiner according to any one of claims 1 to 6; a plurality of light sources optically connected to the respective input optical fibers and outputting laser light; a delivery optical fiber optically connected to the output optical fiber; A light source device comprising:

8. 8. The light source device according to claim 7, wherein the delivery optical fiber is optically connected to an optical head of a laser processing device and transmits the laser beams output from the plurality of light sources to the optical head.

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