JP2011221191A - Beam uniformizing device and optical processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a beam uniformizing device and an optical processing device that can hold a manufacturing cost down and keep optical loss low with ease of manufacturability.SOLUTION: An optical processing device 1 is a device to process a target object W with light and comprises a light source 10, a condenser lens 20, a beam uniformizing device 30, and a transfer lens 40. The beam uniformizing device 30 has a plurality of cores and a clad for covering the plurality of cores, and comprises a multicore optical fiber 32 with a core receiving light L1 at one end thereof, and a large-diameter optical fiber 33 that is optically coupled to the plurality of cores at the other end of the multicore optical fiber 32 and mixes lights incident from the plurality of cores to emit the resulting light.

Description

  The present invention relates to a beam homogenizing apparatus and an optical processing apparatus.

  In recent years, an optical processing apparatus that processes a workpiece (work) using light such as laser light has been studied. In such an optical processing apparatus, it is required to make the intensity of light on the surface of the processing object close to uniform. This is because by making the light intensity uniform, the processing degree of the region to be processed can be made uniform, and the processing accuracy can be increased.

  Non-Patent Document 1 describes a technique for making the intensity of light uniform on the surface of a workpiece. The technique described in this document prepares an optical fiber having a core having a rectangular cross section, and makes laser light incident on one end of the optical fiber, thereby providing light having a uniform intensity (top hat beam). ) Is emitted from the other end of the optical fiber.

Tadahiko Nakai et al., “Development of rectangular core laser guide”, Mitsubishi Electric Industrial Times, October 2009, No. 106, p. 5-8

  In addition to the technique described in Non-Patent Document 1 described above, there are various techniques for making the light intensity uniform. For example, it is possible to make the light intensity uniform by using multiple reflection in a kaleidoscope. Some kaleidoscopes have rectangular waveguides, and others have multiple reflections of light between two mirrors arranged parallel to each other. A device having a rectangular waveguide can multiplex-reflect light by four internal reflecting mirrors and emit light of uniform intensity having a rectangular cross-sectional shape. In addition, a device that multi-reflects light between two mirrors can make the light intensity in one direction uniform by multi-reflecting the S-polarized beam.

  There is also a technique (beam integration) for equalizing the light intensity by dividing one light into a plurality of lights and then superimposing the plurality of lights at one place. Such a technique uses a transmission optical system such as a fly-eye lens in which single lenses of equal size are arranged vertically and horizontally, and a segment mirror in which a large number of plane mirrors are arranged vertically and horizontally. And a technology that uses a simple reflection optical system. For example, in a technique using a fly-eye lens, after dividing one light by a plurality of single lenses, the intensity distribution can be made uniform by collecting the plurality of divided lights at one place.

  However, any of the above-described techniques uses a complicatedly shaped lens, mirror, or optical fiber, which increases the manufacturing cost. Further, the technique using the kaleidoscope has a problem that the light loss is relatively large because the reflectance decreases when the reflection angle of light inside the kaleidoscope increases. In addition, in the technique using a fly-eye lens, a segment mirror, or the like, the intensity distribution (beam profile) of the obtained light is easily influenced by the incident angle of the light to the lens or mirror, and the angle adjustment (beam alignment) of the incident light is difficult. There is a problem.

  The present invention has been made in view of such problems, and provides a beam uniformizing apparatus and an optical processing apparatus that can suppress the optical loss while suppressing the manufacturing cost and can be easily manufactured. For the purpose.

  In order to solve the above-described problem, a beam homogenizing apparatus according to the present invention includes a plurality of cores and a clad covering the plurality of cores, and a first optical fiber that receives light at one end at one end; An optical member that is optically coupled to a plurality of cores at the other end of the first optical fiber and that mixes and emits light incident from the plurality of cores is provided.

  In this beam homogenizer, light is incident on one core at one end of the first optical fiber. When propagating through the first optical fiber, this light is distributed to other cores by crosstalk between the plurality of cores. Thus, the plurality of lights distributed to the plurality of cores are emitted from the other end of the first optical fiber. Since the optical member is optically coupled to the plurality of cores at the other end of the first optical fiber, the plurality of lights are mixed by this optical member to form one light having uniform intensity.

  According to this beam homogenizer, light is split using a first optical fiber (so-called multi-core optical fiber) having a plurality of cores, so that it is compared with the above-described method using a fly-eye lens, a segment mirror, or the like. Manufacturing costs can be significantly reduced. Furthermore, the optical loss can be kept low as compared with a method using a kaleidoscope. Furthermore, there is no difficulty in adjusting the angle of the incident light to the optical fiber, and the beam uniformizing device can be easily manufactured.

  In the beam homogenizer, the optical member may be a second optical fiber, and the second optical fiber may include a core having a thickness that includes all of the plurality of cores. Thereby, the optical member which mixes and radiate | emits the light which injects from the several core of a 1st optical fiber is suitably realizable.

  In the beam homogenizer, the first optical fiber has a central core disposed in the central portion of the first optical fiber and two or more peripheral cores disposed around the central core. The one core may be a central core. Thereby, light can be incident near the center of the first optical fiber and light can be uniformly distributed to other cores (peripheral cores), so that the uniformity of the intensity of the emitted light can be improved.

  In the first optical fiber, the beam homogenizer includes two or more peripheral cores arranged at equal intervals in a region separated from the central axis of the first optical fiber by a certain distance or more. It may be characterized by being. Thereby, since light can be more uniformly distributed to the peripheral core, the uniformity of the intensity of the emitted light can be further improved.

  The beam homogenizer may be characterized in that the intensity of light guided through the plurality of cores is made uniform between the plurality of cores by bending at least a part of the first optical fiber. Good. Thereby, since the intensity | strength of the some light which guides a several core can be made more uniform, the uniformity of the intensity | strength of emitted light can further be improved.

  The beam homogenizer further includes a third optical fiber having an end optically coupled to one core at one end of the first optical fiber and guiding light to the one core. It is good. Thereby, light can be accurately and easily incident on the one core at one end of the first optical fiber. In this case, the beam homogenizer is configured such that the cladding diameter of the first optical fiber and the cladding diameter of the third optical fiber are substantially equal, the core diameter of one core of the first optical fiber, and the third light It is preferable that the core diameter of the fiber is substantially equal. Thereby, light can be incident on the one core with higher accuracy.

  The beam homogenizer may be characterized in that the refractive indexes of the plurality of cores are different from each other. As a result, the speed of light guided through each core varies, and the phases of the plurality of lights emitted from the plurality of cores at the other end of the first optical fiber are different from each other. Can be prevented from interfering with each other, and the uniformity of the intensity of the emitted light from the optical member can be further enhanced.

  An optical processing apparatus according to the present invention is an optical processing apparatus that processes an object to be processed with light, and includes any one of the above-described beam homogenizers and one core at one end of the first optical fiber. A light source coupled to the light beam, and irradiating the workpiece with light emitted from the optical member of the beam homogenizer. According to this optical processing apparatus, it is possible to provide an optical processing apparatus that can suppress light loss while keeping manufacturing costs low and can be easily manufactured by providing any of the beam homogenization apparatuses described above.

  According to the beam homogenizing apparatus and the optical processing apparatus according to the present invention, the optical loss can be suppressed low while the manufacturing cost is suppressed, and the manufacturing can be easily performed.

FIG. 1 is a diagram schematically showing a configuration of an optical processing apparatus according to the present invention. FIG. 2 is a diagram illustrating an example of a cross-sectional structure perpendicular to the longitudinal direction of the first optical fiber. FIG. 3 is a diagram showing another example of a cross-sectional structure perpendicular to the longitudinal direction of the first optical fiber. FIG. 4A is a longitudinal sectional view showing a cross section taken along the line IVa-IVa shown in FIG. 1, and an enlarged structure of a connection portion between the third optical fiber and the first optical fiber. Show. FIG. 4B is a longitudinal sectional view showing a cross section taken along line IVb-IVb shown in FIG. 1, and an enlarged structure of a connection portion between the first optical fiber and the second optical fiber. Show.

  Embodiments of a beam homogenizing apparatus and an optical processing apparatus according to the present invention will be described below in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

(Embodiment)
FIG. 1 is a diagram schematically showing a configuration of an optical processing apparatus according to the present invention. An optical processing apparatus 1 shown in FIG. 1 is an apparatus for processing a workpiece (work) W with light, and includes a light source 10, a condenser lens 20, a beam homogenizer 30, and a transfer lens 40. With.

  The light source 10 generates light L1 having a predetermined wavelength. The light L1 emitted from the light source 10 is preferably laser light. The light source 10 is, for example, a semiconductor laser element that generates single-mode or multi-mode laser light. As the light source 10, various other light sources that generate light having a wavelength suitable for processing the workpiece W can be applied. The light L1 emitted from the light source 10 is collected by the condenser lens 20 and enters the single mode optical fiber 31 of the beam homogenizer 30. When a fiber laser is used as the light source 10, an optical fiber for laser oscillation may be optically connected to the single mode optical fiber 31, and the condenser lens 20 is not necessary.

  The beam homogenizer 30 is an apparatus for homogenizing the light intensity of the light L1 emitted from the light source 10. The beam homogenizer 30 includes a single mode optical fiber 31, a multi-core optical fiber 32, and a large diameter optical fiber 33.

  The single mode optical fiber 31 is the third optical fiber in the present embodiment. The single mode optical fiber 31 has a core diameter capable of propagating light in a single mode. As a constituent material of the single mode optical fiber 31, quartz, resin, or the like is preferable. One end of the single mode optical fiber 31 is optically coupled to the light source 10 via the condenser lens 20, and the other end is fusion-connected to one end of the multi-core optical fiber 32. The single mode optical fiber 31 receives the light L1 from the light source 10 through the condenser lens 20 and guides the light L1 to the multicore optical fiber 32.

  The multi-core optical fiber 32 is the first optical fiber in the present embodiment. The multi-core optical fiber 32 has a plurality of cores and a clad that covers the plurality of cores. As a constituent material of the multi-core optical fiber 32, quartz, resin, or the like is suitable. Here, FIG. 2 and FIG. 3 are diagrams illustrating an example of a cross-sectional structure perpendicular to the longitudinal direction of the multi-core optical fiber 32. A multi-core optical fiber 32a shown in FIG. 2 includes one central core 34 disposed at the center of the multi-core optical fiber 32a (preferably a position including the central axis C of the multi-core optical fiber 32a), and the periphery of the central core 34. 6 peripheral cores 35 disposed in the center, and a central core 34 and a clad 38 covering the peripheral cores 35. Then, the six peripheral cores 35 are arranged in a region separated from the central axis C of the multi-core optical fiber 32a by a distance D1 that is equal to or larger than a predetermined distance D2.

  Also, the multi-core optical fiber 32b shown in FIG. 3 includes one central core 36 disposed at the center of the multi-core optical fiber 32b (preferably a position including the central axis C of the multi-core optical fiber 32b), and the central core 36. 8 peripheral cores 37 disposed in the periphery of the central core 36 and a clad 39 covering the central core 36 and the peripheral core 37. The eight peripheral cores 37 are arranged in a region separated from the central axis C of the multi-core optical fiber 32b by a distance D3 that is equal to or greater than a predetermined distance D4.

  As shown in FIGS. 2 and 3 as an example, the multi-core optical fiber 32 includes a central core disposed in the center of the multi-core optical fiber 32, and two or more peripheral cores disposed around the central core. It is preferable to have. One end of the multi-core optical fiber 32 is fused and connected to the other end of the single mode optical fiber 31 and is optically coupled to the light source 10 via the single mode optical fiber 31 and the condenser lens 20. In this coupling, the position of one core (preferably the central core) of the multi-core optical fiber 32 and the position of the core of the single mode optical fiber 31 coincide with each other. The one core (central core) of the multi-core optical fiber 32 is optically coupled. That is, the light source 10 is optically coupled to one core (center core) at one end of the multi-core optical fiber 32.

  Further, the other end of the multi-core optical fiber 32 is optically coupled to the large-diameter optical fiber 33 by being fused and connected to one end of the large-diameter optical fiber 33. The multi-core optical fiber 32 receives light L1 from the light source 10 through the condenser lens 20 and the single mode optical fiber 31 to one core (preferably the central core). The light L1 is almost uniformly distributed to each of the plurality of cores by crosstalk between the plurality of cores. The plurality of distributed lights are guided by a plurality of cores, and are given to the large-diameter optical fiber 33 from the plurality of cores.

  The multi-core optical fiber 32 preferably has a curved portion 32c as shown in FIG. The curved portion 32c is a part of the multi-core optical fiber 32 wound with a predetermined radius, for example. As described above, since at least a part of the multi-core optical fiber 32 is bent, the intensity of light guided through the plurality of cores of the multi-core optical fiber 32 is made more uniform between the plurality of cores. In addition, the bending of the multi-core optical fiber 32 having such an action is not limited to a mode in which the multi-core optical fiber 32 is wound with a predetermined radius as in the curved portion 32c, but any one or more of the bending diameter, direction, and length. May be changed, and twist may be added.

  Further, the refractive indexes of the plurality of cores of the multi-core optical fiber 32 are equal to each other. Alternatively, the refractive indexes of the plurality of cores of the multicore optical fiber 32 may be different from each other.

  The large-diameter optical fiber 33 is a second optical fiber in the present embodiment, and is an optical member that mixes and emits a plurality of light incident from a plurality of cores of the multi-core optical fiber 32. One end of the large-diameter optical fiber 33 is optically coupled to a plurality of cores at the other end of the multi-core optical fiber 32. Specifically, the large-diameter optical fiber 33 has a core having a thickness that includes all of the plurality of cores of the multi-core optical fiber 32, and the core of the large-diameter optical fiber 33 is a multi-core at one end of the large-diameter optical fiber 33. It contacts all of the plurality of cores of the optical fiber 32. As a constituent material of the large-diameter optical fiber 33, quartz, resin, or the like is suitable.

  A plurality of lights incident on the large-diameter optical fiber 33 from the other end of the multi-core optical fiber 32 are mixed inside the large-diameter core of the large-diameter optical fiber 33 and have a uniform intensity distribution in a plane perpendicular to the optical waveguide direction. It becomes light L2 to have. The light L <b> 2 is emitted from the other end of the large-diameter optical fiber 33 and is irradiated on the surface of the workpiece W through the transfer lens 40.

  Here, FIG. 4A is a longitudinal cross-sectional view showing a cross section taken along the line IVa-IVa shown in FIG. 1, and the structure of the connection portion between the single mode optical fiber 31 and the multicore optical fiber 32 is enlarged. As shown. FIG. 4B is a longitudinal sectional view showing a cross section taken along the line IVb-IVb shown in FIG. 1, and enlarges the structure of the connection portion between the multi-core optical fiber 32 and the large-diameter optical fiber 33. It shows.

  As shown in FIG. 4A, the single mode optical fiber 31 has a single core 51 and a clad 52 that covers the core 51. The multi-core optical fiber 32 has a plurality of cores including a central core 53 disposed in the center of the multi-core optical fiber 32 and a peripheral core 54 disposed around the central core 53. The peripheral core 54 is covered with a clad 55. The core 51 of the single mode optical fiber 31 is optically coupled to one core (preferably the central core 53) of the multi-core optical fiber 32.

  In the present embodiment, the clad diameter of the single mode optical fiber 31 (ie, the outer diameter of the single mode optical fiber 31) Da and the clad diameter of the multicore optical fiber 32 (ie, the outer diameter of the multicore optical fiber 32) Db are substantially equal to each other. . The core diameter Dc of the single mode optical fiber 31 and the core diameter Dd of the core of the multi-core optical fiber 32 (the central core 53 in this embodiment) optically coupled to the core of the single mode optical fiber 31 are substantially equal to each other. .

  As shown in FIG. 4B, the large-diameter optical fiber 33 has a single core 56 and a clad 57 that covers the core 56. As described above, the core diameter De of the core 56 is a size that can include all of the plurality of cores (the central core 53 and the peripheral core 54) of the multi-core optical fiber 32. In other words, the core diameter De of the core 56 is larger than the distance (Df in the drawing) between the outer surfaces of the two peripheral cores 54 farthest apart from each other in the multi-core optical fiber 32.

  Actions and effects exerted by the optical processing apparatus 1 (particularly the beam homogenizing apparatus 30) of the present embodiment having the above configuration will be described. In the optical processing apparatus 1 (beam uniformizing apparatus 30) of the present embodiment, the light L1 is incident on one core (central core 53) at one end of the multi-core optical fiber 32. When propagating through the multi-core optical fiber 32, the light L1 is distributed to other cores (peripheral cores 54) by crosstalk between a plurality of cores. Thus, the plurality of lights distributed to the plurality of cores are emitted from the other end of the multi-core optical fiber 32. At the other end of the multi-core optical fiber 32, the optical member (large-diameter optical fiber 33) is optically coupled to a plurality of cores (the central core 53 and the peripheral core 54). Thus, the light L2 has a uniform intensity.

  According to this optical processing device 1 (beam uniformizing device 30), the light L1 is split using the multi-core optical fiber 32 having a plurality of cores 53 and 54, so that it is compared with a method using a fly-eye lens, a segment mirror, or the like. Thus, the manufacturing cost can be significantly reduced. Furthermore, the optical loss can be kept low as compared with a method using a kaleidoscope. Furthermore, there is no difficulty in adjusting the angle of the incident light to the optical fiber, and the optical processing device 1 and the beam uniformizing device 30 can be easily manufactured.

  As in the present embodiment, the optical member is preferably a large-diameter optical fiber 33, and the large-diameter optical fiber 33 includes a core 56 having a thickness that includes all the cores 53 and 54 of the multi-core optical fiber 32. It is preferable to have. Thereby, an optical member for mixing and emitting a plurality of lights incident from the plurality of cores 53 and 54 of the multi-core optical fiber 32 can be suitably realized. As described above, in this embodiment, the large-diameter optical fiber is exemplified as the optical member. However, the optical member is not limited to this, and a plurality of light incident from the plurality of cores 53 and 54 of the multi-core optical fiber 32 are mixed. Any device that can emit light may be used. For example, an optical element (lens) such as a diffractive optical element (DOE) that can combine a plurality of lights emitted from the multi-core optical fiber 32 into one light may be used as the optical member.

  Further, as in the present embodiment, the multi-core optical fiber 32 includes a central core 53 disposed in the center of the multi-core optical fiber 32 and two or more peripheral cores 54 disposed around the central core 53. It is preferable. In this case, the core into which the light L1 is incident is preferably the central core 53. Thereby, the light L1 can be incident near the center of the multi-core optical fiber 32, and the light L1 can be uniformly distributed to the peripheral core 54, so that the intensity uniformity of the emitted light L2 can be improved. Further, by adopting a configuration in which the light L1 is incident on the central core 53, the optical axes of the single mode optical fiber 31 and the multicore optical fiber 32 can be easily adjusted.

  Further, as in the present embodiment, in the multi-core optical fiber 32, the two or more peripheral cores 54 are arranged at equal intervals in a region separated by a certain distance from the central axis of the multi-core optical fiber 32. It is preferable. Thereby, since the light L1 can be more uniformly distributed to the peripheral core 54, the uniformity of the intensity of the emitted light L2 can be further improved.

  In addition, as in the present embodiment, it is preferable that at least a part of the multi-core optical fiber 32 is bent so that the intensities of the plurality of lights guided through the plurality of cores 53 and 54 are made uniform. Thereby, since the intensity | strength of the some light which guides the several cores 53 and 54 can be made more uniform, the uniformity of the intensity | strength of the emitted light L2 can further be improved.

  Further, as in the present embodiment, the optical processing apparatus 1 (beam uniformizing apparatus 30) includes a single mode optical fiber 31 that guides the light L1 to one core of the multi-core optical fiber 32 (in this embodiment, the central core 53). It is preferable to provide. Thereby, the light L1 can be accurately and easily incident on one core of the multi-core optical fiber 32. In this case, as described above, the cladding diameter Db of the multi-core optical fiber 32 and the cladding diameter Da of the single-mode optical fiber 31 are substantially equal, and the core diameter Dd of one core of the multi-core optical fiber 32 and the single-mode optical fiber It is preferable that the core diameter Dc of 31 is substantially equal. Thereby, the light L1 can be incident on one core (central core 53) of the multi-core optical fiber 32 with higher accuracy.

  Further, as in this embodiment, the refractive indexes of the plurality of cores 53 and 54 of the multi-core optical fiber 32 may be different from each other. As a result, the speed of the plurality of lights guided through the plurality of cores 53 and 54 varies, and the phase of the plurality of lights emitted from the plurality of cores 53 and 54 at the other end of the multi-core optical fiber 32 is changed. Since they are different from each other, it is possible to suppress a plurality of lights from interfering with each other, and to further improve the uniformity of the intensity of the emitted light L2 from the optical member (large-diameter optical fiber 33).

(Example 1)
First, a multi-core optical fiber having the cross-sectional structure shown in FIG. 2 is prepared. In this multi-core optical fiber, for example, the diameter of each core is 9 μm, the center interval between each core is 20 μm, and the refractive index distribution of each core is a step index type with a relative refractive index difference of 0.30%. The diameter is 125 μm. For example, a coating having a diameter of 245 μm may cover the outside of the cladding.

  The multi-core optical fiber is wound 10 times around a reel having a diameter of 30 mm while giving a twist of one rotation per round, and the curved portion 32c in the above embodiment is formed. Then, the single mode optical fiber is fused and connected to one end of the multicore optical fiber to optically couple the core of the single mode optical fiber and the central core of the multicore optical fiber. Also, all the cores of the multi-core optical fiber and the cores of the large-diameter optical fiber are optically coupled by fusion-connecting a large-diameter optical fiber (core diameter 100 μm) to the other end of the multi-core optical fiber. When light is incident on the central core of the multi-core optical fiber via the single mode optical fiber, the optical power is distributed to the peripheral core by crosstalk between the plurality of cores. When a plurality of lights guided through a plurality of cores are incident on the core of a large-diameter optical fiber, uniform light is emitted from the large-diameter optical fiber. Further, in this embodiment, the bending direction of the multi-core optical fiber due to winding on the reel is changed in the longitudinal direction due to twisting, and as a result, the variation in crosstalk between the plurality of cores is reduced, and each core is reduced. The light power is more evenly distributed.

  In this embodiment, the multi-core optical fiber is wound around the reel while being twisted to uniformly distribute the light to the plurality of cores of the multi-core optical fiber, but the optical power in each core is different from each other. May wind a multi-core optical fiber around a reel without twisting. As a result, it is possible to increase (or decrease) the optical power to the specific core. Furthermore, the optical power difference between the cores can be changed by changing the reel diameter.

  In the present embodiment, the bent portion is formed by winding a multi-core optical fiber around a reel. However, since the optical power is distributed to each core according to the crosstalk between the cores without forming such a bent portion, the bent portion of the multi-core optical fiber may be omitted. Depending on the storage form of the multi-core optical fiber, it may be possible to store the multi-core optical fiber without winding it around the reel.

(Example 2)
First, a multi-core optical fiber having the cross-sectional structure shown in FIG. 3 is prepared. In this multi-core optical fiber, for example, the diameter of each core is 8.5 μm, and the relative refractive index difference of each core is 0.37%, 0.36%, 0.35%, 0.34%, 0.33, respectively. %, 0.32%, 0.31%, and 0.30% step index type, and the clad diameter is 125 μm. The center distance between the central core and the peripheral core is 20 μm. Also in this embodiment, for example, a coating having a diameter of 245 μm may cover the outside of the cladding.

  Also in the present embodiment, as in the first embodiment described above, optical power is distributed to each core by crosstalk between a plurality of cores of the multi-core optical fiber. Then, the plurality of distributed lights are incident on the core of the large-diameter optical fiber, and uniformed light is emitted from the large-diameter optical fiber. In this embodiment, since the refractive indexes of the plurality of cores of the multi-core optical fiber are different from each other, the phases of the plurality of lights propagating through the multi-core optical fiber vary due to the difference in optical path length. Accordingly, highly uniform light with reduced coherence (interference noise and speckle is small) is emitted from the exit end of the large-diameter optical fiber.

  The beam uniformizing apparatus and the optical processing apparatus according to the present invention are not limited to the above-described embodiments and examples, and various other modifications are possible. For example, in the above-described embodiment, the configuration including the third optical fiber (single mode optical fiber 31) is exemplified. However, in the beam homogenizer and the optical processing device according to the present invention, the third optical fiber is omitted. Light may be incident directly on one end of the first optical fiber (or via another optical system).

  DESCRIPTION OF SYMBOLS 1 ... Optical processing apparatus, 10 ... Light source, 20 ... Condensing lens, 30 ... Beam uniformizing apparatus, 31 ... Single mode optical fiber, 32, 32a, 32b ... Multi-core optical fiber, 32c ... Curved part, 33 ... Large aperture light Fiber, 34, 36, 53 ... center core, 35, 37, 54 ... peripheral core, 38, 39, 52, 55, 57 ... clad, 40 ... transfer lens, 51, 56 ... core, W ... workpiece.

Claims (9)

A first optical fiber having a plurality of cores and a clad covering the plurality of cores and receiving light at one core at one end;
An optical member optically coupled to the plurality of cores at the other end of the first optical fiber and mixing and emitting light incident from the plurality of cores. . The optical member is a second optical fiber;
2. The beam uniformizing apparatus according to claim 1, wherein the second optical fiber has a core having a thickness including all of the plurality of cores. The first optical fiber has a central core disposed in a central portion of the first optical fiber, and two or more peripheral cores disposed around the central core;
The beam uniformizing device according to claim 1, wherein the one core is the central core.   In the first optical fiber, the two or more peripheral cores are arranged at equal intervals in a region separated from the central axis of the first optical fiber by a certain distance or more. The beam homogenizer according to claim 3.   The intensity of light guided through the plurality of cores is made uniform between the plurality of cores by bending at least a part of the first optical fiber. 5. The beam homogenizer according to any one of 4 above.   The first optical fiber further comprises a third optical fiber having an end optically coupled to the one core at one end of the first optical fiber and guiding light to the one core. The beam homogenizer according to any one of 1 to 5. The cladding diameter of the first optical fiber and the cladding diameter of the third optical fiber are substantially equal;
The beam uniformizing apparatus according to claim 6, wherein the core diameter of the one core of the first optical fiber and the core diameter of the third optical fiber are substantially equal.   The beam homogenizer according to any one of claims 1 to 7, wherein the refractive indexes of the plurality of cores are different from each other. An optical processing device that processes an object to be processed with light,
The beam homogenizer according to any one of claims 1 to 8,
A light source optically coupled to the one core at one end of the first optical fiber,
An optical processing apparatus, wherein the processing object is irradiated with light emitted from the optical member of the beam homogenizing apparatus.

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