JP2021051226A - Beam shaper, processing device, and processing method - Google Patents

Abstract

To provide a beam shaper with a simple configuration capable of suppressing rapid change in temperature of a workpiece.SOLUTION: A beam shaper (BS) provided herein comprises an axicon lens (133) and a rotating mechanism (135) for rotating the axicon lens (133). Defining a main axis (L3) as the normal of a bottom face of a second end face (end face 133b) passing through an apex of the second end face (end face 133b), the beam shaper satisfies at least either of: a first condition that the normal (axis L2) of the first end face (end face 133a) is tilted with respect to a center axis (L1); and a second condition that the main axis (L3) and the center axis (L1) are out of alignment.SELECTED DRAWING: Figure 1

Description

The present invention relates to a beam shaper that converts a Gaussian beam into a Bessel beam. It also relates to a processing apparatus provided with such a beam shaper. Further, the present invention relates to a processing method using such a beam shaper.

Axicon lenses that convert a collimated Gaussian beam into a Bessel beam are widely used. Patent Document 1 discloses a beam shaper provided with an axicon lens (“laser beam shaping device” in Patent Document 1). The Bessel beam emitted from the axicon lens has high power in the interference region. Therefore, by forming the interference region of the Bessel beam emitted from the axicon lens on the work, efficient processing becomes possible.

JP-A-2017-142402

Laser processing of metals has the following problems. First, when the power of the laser beam irradiating the work is high, the molten metal scattered from the periphery of the keyhole becomes spatter (it is necessary to remove the spatter after laser processing). Secondly, rapid cooling after laser irradiation causes thermal strain or cracks in the work. Third, if the molten metal solidifies before the gas mixed in the molten metal is dissipated, blow holes occur.

In order to avoid such a problem, a technique called wobbling irradiation of laser light is used. In wobbling irradiation, the sudden temperature change of the work can be suppressed by swaying the locus of the irradiation point of the laser beam, and the above-mentioned problem can be suppressed.

However, in the conventional beam shaper, it has been difficult to realize the wubbing of the Bessel beam emitted from the axicon lens. This is because the interference region of the Bessel beam emitted from the axicon lens is formed in the vicinity of the axicon lens. For this reason, it is difficult to provide a mechanism for wobbling the Bessel beam (movable mirror, rotatable wedge substrate, etc.) between the axicon lens and the work.

One aspect of the present invention has been made in view of the above problems. One aspect of the present invention is to realize a beam shaper, a processing device, or a processing method capable of suppressing a sudden temperature change of a work with a simple configuration.

The beam shaper according to the first aspect of the present invention includes a first end face that is planar and a second end face that is conical or oblique conical, and is an axicon arranged on the optical path of the Gaussian beam. A lens and a rotation mechanism for rotating the axicon lens with the central axis of the Gaussian beam as a rotation axis are provided, and the normal line of the bottom surface of the second end face passing through the apex of the second end face is used as a main axis. The axicon lens has one of a first condition that the normal line of the first end face is inclined with respect to the central axis and a second condition that the main axis and the central axis are deviated from each other. A configuration has been adopted that satisfies at least one.

According to the above configuration, a beam shaper capable of suppressing a sudden temperature change of the work can be realized with a simple configuration.

The beam shaper according to the second aspect of the present invention is the beam shaper according to the first aspect described above, wherein the second end face has a conical surface shape, and the axicon lens satisfies the first condition and the second aspect. The axis of rotation of the end face coincides with the central axis.

According to the above configuration, the normal of the first end face is tilted with respect to the central axis, so that the center of the Bessel beam generated by passing through the axicon lens is deviated from the rotation axis. It is formed in a normal position. Then, the rotation mechanism rotates the axicon lens around the rotation axis. Therefore, the beam shaper according to the second aspect can make the locus of the center of the Bessel beam circular.

The beam shaper according to the third aspect of the present invention is the beam shaper according to the above-described first or second aspect, wherein the second end face is conical, and the first end face is on the bottom surface of the second end face. It is configured to be tilted with respect to it.

The axicon lens configured in this way can be suitably used for the beam shaper according to one aspect of the present invention.

The beam shaper according to the third aspect of the present invention is configured such that the main axis of the beam shaper according to the first aspect described above is parallel to the central axis and satisfies the second condition.

According to the above configuration, since the main axis and the central axis are deviated from each other, the center of the Bessel beam generated by passing through the axicon lens is formed at a position deviated from the rotation axis. Then, the rotation mechanism rotates the axicon lens around the rotation axis. Therefore, the beam shaper according to the fourth aspect can make the locus of the center of the Bessel beam circular.

In the beam shaper according to the fourth aspect of the present invention, the second end face of the beam shaper according to the fifth aspect of the present invention has an oblique conical shape, and the first end face is parallel to the bottom surface of the second end face. Is configured to be.

The axicon lens configured in this way can be suitably used for the beam shaper according to one aspect of the present invention.

In the processing apparatus according to the sixth aspect of the present invention, a configuration is adopted in which a processing head including the beam shaper according to any one of the first to fifth aspects of the present invention is provided and the work is irradiated with a Bessel beam output from the beam shaper. ing.

According to the above configuration, it is possible to realize a processing apparatus capable of suppressing a sudden temperature change of the work with a simple configuration.

The processing method according to aspect 7 of the present invention includes a first end face that is planar and a second end face that is conical or oblique conical, and is an axis arranged on the optical path of a Gaussian beam. A processing method for irradiating a work with a Bessel beam generated by passing through a conical, including a step of rotating the axicon lens with the central axis of the Gaussian beam as a rotation axis, and a step of rotating the axicon lens on the second end face. A configuration is adopted in which the normal line of the bottom surface of the second end face passing through the apex is the main axis, and at least one of the normal line of the first end face and the main axis is inclined with respect to the central axis. ..

According to the above configuration, a processing method capable of suppressing a sudden temperature change of the work can be realized with a simple configuration.

According to one aspect of the present invention, it is possible to realize a beam shaper, a processing device, or a processing method capable of suppressing a sudden temperature change of a work.

(A) is a block diagram showing a configuration of a processing apparatus according to an embodiment of the present invention. (B) and (c) are cross-sectional views showing the structure of a processing head included in the processing apparatus. FIG. 1A is a perspective view and a cross-sectional view showing the shape of the axicon lens included in the beam shaper shown in FIG. 1B. (B) is a perspective view and a cross-sectional view showing the shape of a first modification of the axicon lens provided in the beam shaper shown in FIG. 1 (b). (C) is a perspective view and a cross-sectional view showing the shape of a second modification of the axicon lens provided in the beam shaper shown in FIG. 1 (b). Each of (a), (b), and (c) is a graph showing the intensity distribution of the Bessel beam on the y-axis obtained by the processing apparatus shown in FIG. 1, and the intensity distribution of the Bessel beam on the xy plane. It is a graph which shows. Each of (a) and (b) is an intensity distribution on the y-axis of the Bessel beam obtained by a processing apparatus equipped with a beam shaper equipped with an axicon lens of the second modification shown in FIG. 2 (c). Is a graph showing the intensity distribution of the Bessel beam on the xy plane.

[First Embodiment]
(Configuration of processing equipment)
The configuration of the processing apparatus 1 according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2. In FIG. 1, FIG. 1A is a block diagram showing a configuration of a processing apparatus 1, and FIGS. 1B and 1C are cross-sectional views of a processing head 13 included in the processing apparatus 1. Here, the cross section shown in FIG. 1 (b) is an AA'cross section obtained by cutting the processing head 13 along the AA' line shown in FIG. 1 (c), and the cross section shown in FIG. 1 (c) is processed. It is a BB'cross section of the head 13 cut along the BB' line shown in FIG. 1 (b). 2A is a perspective view and a cross-sectional view showing the shape of the axicon lens 133 included in the beam shaper BS shown in FIG. 1B, and FIGS. 2B and 2C are beam shapers. It is a perspective view and the cross-sectional view which shows the shape of the 1st modification and the 2nd modification of the Axicon lens 133 provided by BS. Here, the cross-sectional view shown in FIG. 2A is a CC'cross section cut along a plane including the CC'line shown in the perspective view of FIG. 2A and the apex of the end surface 133b of the axicon lens 133 described later. The cross-sectional view shown in FIG. 2B is a cross-sectional view taken along a plane including the DD'line shown in the perspective view of FIG. 2B and the apex of the end surface 133b of the axicon lens 133A described later. The cross-sectional view shown in FIG. 2C is a cross-sectional view taken along a plane including the EE'line shown in the perspective view of FIG. 2C and the apex of the end face 133Bb of the axicon lens 133B described later. Is.

In addition, in FIG. 2A, the axicon lens 133 is shown so that the top and bottom are opposite to the state shown in FIG. 1B. In FIGS. 2B and 2C, the Axicon lenses 133A and 133B are shown so that the vertical direction is the same as that of the Axicon lens 133 shown in FIG. 2A. Further, in FIGS. 2A to 2C, the rotary lens holder 134 for holding the Axicon lenses 133, 133A, 133B is not shown. Further, in each of (a), (b), and (c) of FIG. 2, the cylindrical SL shown by the alternate long and short dash line is a cylinder circumscribing the axicon lenses 133, 133A, and 133B, respectively.

The processing device 1 is a device for processing the work W using a laser beam, and as shown in FIG. 1A, the laser light source 11, the delivery fiber 12, the processing head 13, and the movable stage 14 And have.

The laser light source 11 is a device that generates laser light. The delivery fiber 12 is an optical fiber that guides the laser light generated by the laser light source 11. The processing head 13 is a device that irradiates the work W with a laser beam guided through the delivery fiber 12. The movable stage 14 is a device that moves the work W in a direction orthogonal to the traveling direction of the laser beam emitted from the processing head 13. As the laser light source 11, for example, a fiber laser is used. As the delivery fiber 12, for example, a multimode fiber is used. As the movable stage 14, for example, a precision XY stage is used.

As shown in FIG. 1B, the processing head 13 includes a housing 130, a collimating lens 131, an axicon lens 133, a rotary lens holder 134, and a rotation mechanism 135. The collimating lens 131, the axicon lens 133, and the rotation mechanism 135 function as a beam shaper BS that forms a beam emitted from the delivery fiber 12 while converting it from a Gaussian beam G, G'to a Bessel beam B. The beam shaper BS is an aspect of the present invention.

The housing 130 is a tubular structure in which one end (upper end in FIG. 1) is closed and the other end (lower end in FIG. 1) is open. The delivery fiber 12 is drawn into the housing 130 through an insertion hole provided in the housing 130. The light emitted from the delivery fiber 12 becomes a Gaussian beam G that diverges (the beam diameter gradually increases along the optical path).

A collimating lens 131 is arranged on the optical path of the Gaussian beam G. The collimating lens 131 is a plano-convex collimating lens having a flat surface and a spherical convex surface. Collimator lens 131, the (collimator lens 131) flat surface, faces the exit surface of the delivery fiber 12, and, so as to be perpendicular to the center axis _{L 1} of the delivery fiber 12, the lens holder 132 of the housing 130 It is fixed to the inner surface. Central axis of the collimating lens 131 coincides with the center axis _{L 1} of the delivery fiber 12. The light emitted from the collimating lens 131 becomes a collimated Gaussian beam G'(with a constant beam diameter along the optical path). The central axis of the Gaussian beam G, G 'are consistent with each of the center axes of L ₁ and the collimator lens 131 of the delivery fiber 12. Therefore, the central axis L ₁ is also the central axis of the delivery fiber 12, the central axis of the collimating lens 131, and the central axis of the axicon lens 133.

An axicon lens 133 is arranged on the optical path of the Gaussian beam G'. The axicon lens 133 has an end face 133a and an end face 133b which are a pair of end faces (that is, an entrance surface and an exit surface) that transmit the Gaussian beam G'. As shown in FIG. 1B, the axicon lens 133 is arranged so that the end surface 133a functions as an incident surface and the end surface 133b functions as an exit surface.

As shown in FIG. 1B, the end face 133a, which is an example of the first end face, is a flat surface, and the end face 133b, which is an example of the second end face, is a conical surface. However, in one aspect of the present invention, the first end face and the second end face are not limited to this. The first end face may be at least flat, and the second end face may be at least conical or conical. In this embodiment, the end face 133b is a conical surface. Therefore, the rotation axis of the end face 133b passes through the apex of the end face 133b and is orthogonal to the bottom surface 133c of the end face 133b. Therefore, the axis of rotation of the end face 133b is the normal of the bottom surface 133c passing through the apex of the end face 133b. As described above, the axicon lens 133 has a shape in which the end surface 133b has a conical surface shape (conical surface in the present embodiment) and the end surface 133a is inclined with respect to the bottom surface 133c. In axicon lens 133, referred to an axis parallel to the normal of the end face 133a and the shaft _{L 2,} it refers to the axis of rotation of the end surface 133b and the main shaft _{L 3.}

Axicon lens 133, so that the end face 133a faces the spherical convex surface of the collimator lens 131, and, as the main shaft _{L 3} coincides with the center axis _{L 1,} and the axis _{L 2} is with respect to the center axis _{L 1} It is held inside the rotary lens holder 134 so as to be tilted. More specifically, located on the center axis _{L 1} is the vertex of the end surface 133b, and, as a shaft _{L 2} and the center axis _{L 1} forms a tilt angle theta _12, axicon lens 133, rotary lens holder 134 It is held inside. The state in which the axis L ₂ is tilted with respect to the center axis L ₁ is one embodiment of a state where a shaft L ₂ and the center axis L ₁ is shifted. Further, the spindle L ₃ is tilted with respect to the axis L _2.

The rotary lens holder 134 includes, for example, an inner holder 134a fixed to the end surface (a portion forming a contour when viewed in a plan view) of the axicon lens 133, and an outer holder 134b fixed to the inner side surface of the housing 130. It can be configured by a bearing 134c interposed between the inner holder 134a and the outer holder 134b. The central axis of the inner holder 134a is disposed so as to coincide with the center axis L _1. Thus, the rotary lens holder 134, it is possible to rotate freely axicon lens 133 on the central axis L ₁ as the rotation axis. In this way, the axicon lens 133 is rotatably held on the inner surface of the housing 130 via the rotary lens holder 134.

The rotation mechanism 135 is a mechanism for rotating the axicon lens 133 via the inner holder 134a of the rotary lens holder 134. The rotation mechanism 135 can be composed of, for example, a shaft with a screw threaded to be screwed with the gear-shaped outer surface of the inner holder 134a, and a motor (not shown) for rotating the shaft.

The light emitted from the axicon lens 133 becomes a Bessel beam B. As described above, since the axis L ₂ and the central axis L ₁ form an inclination angle θ ₁₂ , the center of the vessel beam B deviates from the _{central axis L 1} in a direction corresponding to the direction in which the _{axis L 2 is inclined.} In the (b) Figure 1, z-axis positive direction side of the portion of the shaft L ₂ is inclined to the y-axis positive direction from the center axis L _1, as a result, the center of the Bessel beam B, y-axis positive It is shifted to the direction side. Sonouede, by axicon lens 133 is rotated on the central axis L ₁ as the rotation axis, since the direction of the axis L ₂ is tilted is rotated, the center of the Bessel beam B, on the xy plane perpendicular to the center axis L ₁ Move while drawing a circular trajectory.

In one aspect of the present invention, an axicon lens 133 including a planar end surface 133a and a conical or oblique conical end surface 133b and arranged on the optical path of the Gaussian beam G'is provided. Bessel beam B generated by transmitting a processing method of irradiating the workpiece W, also includes a processing method comprising the step of rotating the axicon lens 133 on the central axis L ₁ as the rotation axis. In the processing method according to an embodiment of the present invention, at least one of and the main shaft L ₃ (axis L ₂ in other _words) the normal of the end face 133a is inclined with respect to the central axis L _1. In the axicon lens 133 shown in FIGS. 1 and 2 (a), the end surface 133b is a conical surface, and the axis L ₂ is tilted with respect to the central axis L _1.

(Modified example of Axicon lens 133)
Each of the axicon lens 133A and the axicon lens 133B will be described with reference to FIGS. 2 (b) and 2 (c), respectively. The axicon lens 133A is a first modification of the axicon lens 133, and the axicon lens 133B is a second modification of the axicon lens 133.

The axicon lens 133A is an axicon lens having the same shape as the axicon lens 133. However, the axicon lens 133A is held in a different direction inside the rotary lens holder 134 as compared with the axicon lens 133. Specifically, in the axicon lens 133A, the inside of the rotary lens holder 134 is such that the _{axis L 2} is parallel to the central axis L ₁ and the main axis L ₃ and the central axis L ₁ form an inclination angle θ _13. It is held in.

In the axicon lens 133A, the main axis L ₃ and the central axis L ₁ form an inclination angle θ _{13 , so that the main axis L 3} is inclined at the center of the Bessel beam B as in the case of using the axicon lens 133A. deviates from the center axis L ₁ in a direction corresponding to the direction. Sonouede, Aki by axicon lens 133 is rotated on the central axis L ₁ as the rotation axis, since the direction of the main shaft L ₃ is tilted is rotated, the center of the Bessel beam B, a circle in a plane perpendicular to the central axis L ₁ Move while drawing the trajectory of the shape.

In this modification, the axicon lens 133A, as in the axis _{L 2} is parallel to the center axis _{L 1,} i.e., so that the end face 133a is perpendicular to the center axis _{L 1,} the interior of the rotary lens holder 134 It is held in. However, in one aspect of this modification, the main axis L ₃ and the central axis L ₁ need only be tilted, and the central axis L ₁ and the end face 133a may or may not be orthogonal to each other. ..

The axicon lens 133B has an end face 133Ba and an end face 133Bb which are a pair of end faces (that is, an entrance surface and an exit surface) that transmit the Gaussian beam G'. As shown in FIG. 2C, the axicon lens 133B is arranged so that the end surface 133Ba functions as an incident surface and the end surface 133Bb functions as an exit surface, similarly to the axicon lens 133 and the axicon lens 133A. Has been done.

As shown in FIG. 2C, the end face 133Ba, which is an example of the first end face, is a flat surface, and the end face 133Bb, which is an example of the second end face, has an oblique conical surface shape (in this embodiment, an oblique cone). The end surface 133Ba is parallel to the bottom surface 133Bc of the end surface 133Bb. In the following, the axicon lens 133B, referred to the normal of the bottom surface 133Bc end surface 133Ba through the apex of the end surface 133Bb the spindle _{L 4.} In the axicon lens 133B, as shown in FIG. 2C, the _{angle formed by the end face 133Bb and the axis L 4} changes according to the orientation centered on the apex (or the main axis L _4). The angle between the end surface 133Bb and the spindle L ₄ are, orientation with respect to vertices becomes minimum angle theta _min when a y-axis negative direction, the maximum angle theta _max in the case of y-axis positive direction. As a result, cross-section and a parallel sectional center of the bottom surface 133Bc end surface 133Bb is not located on the main shaft _{L 4.} In the following, the angle between the end surface 133Bb and the spindle L ₄ is a direction in which the maximum angle theta _max called minimum inclination direction, referred to as the maximum inclination direction and a direction to minimize the angle theta _min.

Axicon lens 133B is the main shaft L ₄ is parallel to the center axis L _1, and, as the main shaft L ₄ and the center axis L ₁ are separated, it is held inside the rotary lens holder 134. In FIG. 2C _{, the distance between the main axis L 4} and the central axis L ₁ is referred to as a distance ΔL.

Aki In axicon lens 133B, the angle between the end surface 133Bb and the spindle L ₄ is, and changes according to the orientation around the apex, and, since the main shaft L ₄ and the center axis L ₁ is separated , the center of the Bessel beam B is deviated from the center axis L ₁ and the difference between the maximum angle theta _max and the minimum angle theta _min, in a direction corresponding to the direction of separating the axis L ₄ from the center axis L _1. Sonouede, Aki by axicon lens 133 is rotated on the central axis L ₁ as the rotation axis, since the orientation of separating the axis L ₄ from the center axis L ₁ rotates, the center of the Bessel beam B is perpendicular to the central axis L ₁ It moves while drawing a circular locus on the plane.

(Intensity distribution of Bessel beam B)
The intensity distribution of the Bessel beam B will be described with reference to FIGS. 3 and 4.

Each of (a), (b), and (c) of FIG. 3 is xy of the Bessel beam B obtained by the processing apparatus 1 using the beam shaper BS provided with the axicon lens 133 shown in FIG. 2 (a). It is a graph which shows the intensity distribution on a plane. In each of (a), (b), and (c) of FIG. 3, the axis L ₂ is inclined from the central axis L ₁ to the positive direction of the y axis, and the inclination angle θ ₁₂ is θ. The intensity distributions obtained when = 0.1 degrees, 0.5 degrees, and 1 degree are shown.

Each of (a) and (b) of FIG. 4 shows the intensity distribution of the vessel beam B on the xy plane obtained by the processing apparatus 1 using the beam shaper BS provided with the axicon lens 133B shown in FIG. 2 (c). It is a graph which shows. In FIG. 4A, the maximum angle θ _max = 89 degrees, the minimum angle θ _min = 88 degrees, the minimum inclination direction is in the positive direction of the y-axis, and the maximum inclination direction is in the negative direction of the y-axis. The intensity distribution obtained in the case is shown. In FIG. 4B, the maximum angle θ _max = 89 degrees, the minimum angle θ _min = 87 degrees, the minimum inclination direction is in the positive direction of the y-axis, and the maximum inclination direction is in the negative direction of the y-axis. The intensity distribution obtained in the case is shown.

In FIG. 3 (a), referring to each of (b), and (c), the larger the inclination angle theta ₁₂ is, the distance ΔP of the center of the center axis L ₁ and the Bessel beam B in the xy plane Can be seen to spread. When the inclination angle θ ₁₂ was θ = 0.1 degrees, 0.5 degrees, and 2 degrees, the distances ΔP were ΔP = 6.1 μm, 30.5 μm, and 61.1 μm. Therefore, when the inclination angle θ ₁₂ is θ = 0.1 degrees, 0.5 degrees, and 2 degrees, the radius of the center of the Bessel beam B is approximately 6. Draw circular trajectories of 1 μm, 30.5 μm, and 61.1 μm.

Referring to each of the FIGS. 4 (a) and (b), as the difference between the maximum angle theta _max and the minimum angle theta _min is large, the distance between the center of the center axis L ₁ and the Bessel beam B in the xy plane It can be seen that ΔP spreads. When the maximum angle θ _max = 89 degrees and the minimum angle θ _min = 88 degrees, ΔP = 774 μm, and when the maximum angle θ _max = 89 degrees and the minimum angle θ _min = 87 degrees, ΔP = 1146 μm. It became. Therefore, when the maximum angle θ _max = 89 degrees and the minimum angle θ _min = 88 degrees, by rotating the axicon lens 133B, the center of the Bessel beam B is a circular locus having a radius of approximately 774 μm. When the maximum angle θ _max = 89 degrees and the minimum angle θ _min = 87 degrees, by rotating the axicon lens 133B, the center of the Bessel beam B has a circular shape with a radius of approximately 1146 μm. Draw a trajectory.

[Additional notes]
The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention.

1 Processing equipment 11 Laser light source 12 _{Deliverable fiber L 1} Central axis BS Beam shaper G, G'Gaussian beam B Bessel beam 13 Processing head 130 Housing 131 Collimated lens 133, 133A, 133B Axicon lens 133a, 133Ba End face (first end face) )
L ₂ axis (axis parallel to the normal of the first end face)
133b, 133Bb end face (second end face)
L ₃ , L ₄ spindle (the bottom line of the second end face that passes through the apex of the second end face)
134 Rotating lens holder 135 Rotating mechanism

Claims (7)

An axicon lens arranged on the optical path of a Gaussian beam, including a first end face that is planar and a second end face that is conical or oblique conical.
A rotation mechanism for rotating the axicon lens with the central axis of the Gaussian beam as a rotation axis is provided.
With the normal of the bottom surface of the second end face passing through the apex of the second end face as the main axis, the axicon lens has a first aspect in which the normal of the first end face is inclined with respect to the central axis. And at least one of the second condition that the main axis and the central axis are deviated from each other.
A beam shaper that features that. The second end face is conical and has a conical shape.
The axicon lens satisfies the first condition and meets the above conditions.
The rotation axis of the second end face coincides with the central axis.
The beam shaper according to claim 1. The second end face is conical and has a conical shape.
The first end face is inclined with respect to the bottom surface of the second end face.
The beam shaper according to claim 1 or 2. The spindle is parallel to the central axis and
The second condition is satisfied.
The beam shaper according to claim 1. The second end face has an oblique conical surface shape.
The first end face is parallel to the bottom surface of the second end face.
The beam shaper according to claim 4. A processing head including the beam shaper according to any one of claims 1 to 5 is provided, and a Bessel beam output from the beam shaper is applied to the work.
A processing device characterized by this. A vessel generated by passing through an axicon lens arranged on the optical path of a Gaussian beam, including a first end face that is planar and a second end face that is conical or oblique conical. It is a processing method that irradiates the work with a beam.
A step of rotating the axicon lens with the central axis of the Gaussian beam as a rotation axis is included.
With the normal of the bottom surface of the second end face passing through the apex of the second end face as the main axis, at least one of the normal of the first end face and the main axis is inclined with respect to the central axis.
A processing method characterized by that.

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