JP2018025606A - Beam shaping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a beam shaping device with which it is possible to adjust a beam shape to an intended ellipticity while maintaining an image formation condition.SOLUTION: A beam shaping device 100 comprises: measurement means for measuring the beam shape of a laser beam 11 at a monitor position 5 on an optical axis; a first cylindrical lens 6 for transmitting a laser beam having passed through the monitor position; a second cylindrical lens 7 whose condensing direction is orthogonal to that of the first cylindrical lens, for transmitting a laser beam having passed through the first cylindrical lens; bending mirrors 8, 9 for changing the direction of progression of a laser beam having passed through the second cylindrical lens; and movement mechanisms 12, 13, 14 for moving each of the first and second cylindrical lenses and the bending mirrors in the direction of the optical axis. The movement mechanisms are controlled on the basis of the beam shape at the monitor position so that the monitor position and a reference position 10 which a laser beam goes through after its direction of progression is changed by the bending mirrors satisfy an image formation condition.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a beam shaping device for shaping a beam shape of a laser beam.

  As a conventional beam shaping device, a first cylindrical lens, a first cylindrical lens, a second cylindrical lens positioned in a direction in which a light collecting direction is orthogonal to each other, a first cylindrical lens, and a second cylindrical lens There has been proposed a beam shaping mechanism having an interval adjusting mechanism capable of adjusting the interval between the two (see Patent Document 1).

  According to the beam shaping mechanism of Patent Document 1, the ellipticity, which is the ratio of the major axis to the minor axis of the elliptical beam shape, can be changed as appropriate.

JP 2007-136477 A

  In the beam shaping mechanism of Patent Document 1, when the ellipticity, the divergence angle, or the beam quality of a beam generated by a laser oscillator that is a light source changes with time, how the first and second change according to the change of the light source. If the cylindrical lens position and interval are set, can the target elliptical beam shape be secured at the reference position, which is a predetermined position on the optical axis, and the beam shape be maintained constant? The user cannot get any information. Therefore, it takes time and effort to adjust the optical system with trial and error, and the adjustment procedure differs depending on the user. Therefore, even if the target ellipticity can be adjusted, the adjusted beam diameter varies depending on the user. .

  The present invention has been made in view of the above, and an object thereof is to obtain a beam shaping device capable of adjusting a beam shape to a target ellipticity while maintaining imaging conditions.

  In order to solve the above-described problems and achieve the object, the present invention provides a measuring means for measuring the beam shape of the laser light at the monitor position on the optical axis, and a first means for transmitting the laser light having passed through the monitor position. The cylindrical lens, the second cylindrical lens and the first cylindrical lens are orthogonal to each other in the condensing direction, and transmits the laser light passing through the first cylindrical lens, and the traveling direction of the laser light passing through the second cylindrical lens. A folding mirror to be changed, and a moving mechanism for moving the first and second cylindrical lenses and the folding mirror in the direction of the optical axis. The present invention controls the moving mechanism based on the beam shape at the monitor position so that the monitor position and the reference position through which the laser light passes after the traveling direction is changed by the bending mirror satisfy the imaging condition. Features.

  According to the present invention, it is possible to realize a beam shaping device capable of adjusting a beam shape to a target ellipticity while maintaining imaging conditions.

1 is a configuration diagram of a beam shaping device according to a first embodiment of the present invention. The figure which shows the positional relationship of the optical system between the monitor position and reference position in the beam shaping apparatus concerning Embodiment 1. FIG. The figure which shows the beam shape in the monitor position in the beam shaping apparatus concerning Embodiment 1. FIG. The figure which shows the beam shape in the reference position in the beam shaping apparatus concerning Embodiment 1. FIG. The figure which shows another positional relationship of the optical system between the monitor position in the beam shaping apparatus concerning Embodiment 1, and a reference position. Configuration diagram of a beam shaping device according to a second exemplary embodiment of the present invention. Configuration diagram of a beam shaping apparatus according to a third embodiment of the present invention. Configuration diagram of a beam shaping device according to a fourth embodiment of the present invention.

  Hereinafter, a beam shaping device according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram of a beam shaping device 100 according to the first exemplary embodiment of the present invention. The laser beam 11 emitted from the laser oscillator 1 passes through the transmission optical system 2 and reaches the partial reflection mirror 3. The partial reflection mirror 3 reflects a part of the incident beam of the laser light 11 by 90 ° and makes it incident on a beam shape monitor 4 which is a measuring means for measuring the beam shape of the laser light 11. As the beam shape monitor 4, a device that measures a beam intensity distribution by a CMOS (Complementary Metal Oxide Semiconductor) or a CCD (Charge-Coupled Device), or a power measurement device equipped with a movable aperture having a shape such as a knife edge shape is used. It is done. The beam shape of the laser beam 11 measured by the beam shape monitor 4 coincides with the beam shape at the monitor position 5 where the beam shape is monitored on the optical axis of the beam transmitted through the partial reflection mirror 3.

  The laser beam 11 that has passed through the monitor position 5 passes through the first cylindrical lens 6 and the second cylindrical lens 7 in order, and is transmitted in a “U” shape by the two folding mirrors 8 and 9. It passes through the reference position 10 of the shaped beam. The reference position 10 is fixed.

  Here, the direction from the right to the left of the paper is the first direction, the direction from the top to the bottom of the paper is the second direction, and the direction from the left to the right of the paper is the third direction. The fact that the laser beam 11 is transmitted in a “U” shape by the two folding mirrors 8 and 9 means that the traveling direction of the laser beam 11 is changed from the first direction to the second direction, and then the second direction. That is, the transmission is changed from the first direction to the third direction. That is, the laser beam 11 is transmitted in a “U” shape when the first direction as the first traveling direction of the laser beam 11 and the third direction as the last traveling direction are parallel and opposite to each other. This means that the laser beam 11 is transmitted with the change.

  However, the first traveling direction and the last traveling direction of the laser beam 11 bent by the two bending mirrors 8 and 9 are determined by moving the bending mirrors 8 and 9 as will be described later and the monitor position 5 and the reference position 10. As long as the optical path length between them can be changed, they do not necessarily have to be parallel. Further, the number of bending mirrors is not necessarily limited to two, and may be more than that.

  Behind the reference position 10 in the third direction, which is the beam traveling direction, an optical system 15 for imaging and transmitting the beam of the laser light 11 that has passed through the reference position 10 in the beam traveling direction is disposed.

  The first cylindrical lens 6 and the second cylindrical lens 7 are installed so that the light collection direction of the first cylindrical lens 6 and the light collection direction of the second cylindrical lens 7 are orthogonal to each other. The first cylindrical lens 6 is mounted on a moving mechanism 12 that can move the first cylindrical lens 6 in the direction of the optical axis, and the second cylindrical lens 7 is the second cylindrical lens 7. Is mounted on a moving mechanism 13 that can move in the direction of the optical axis. Further, the two folding mirrors 8 and 9 are both mounted on the moving mechanism 14. The moving mechanism 14 is movable in parallel with the direction of the optical axis where the beam of the laser beam 11 enters and exits the bending mirrors 8 and 9, that is, the first and third directions.

  FIG. 2 is a diagram illustrating a positional relationship of the optical system between the monitor position 5 and the reference position 10 in the beam shaping apparatus 100 according to the first embodiment. FIG. 2 shows an optical distance relationship unlike the actual arrangement of FIG. 1, and the distance between the monitor position 5 and the reference position 10, the first cylindrical lens with respect to the monitor position 5 and the reference position 10. 6 shows the positional relationship between the sixth cylindrical lens 7 and the second cylindrical lens 7.

Assuming that the first cylindrical lens 6 has a light collecting performance in the x direction on the cross section perpendicular to the optical axis, the second cylindrical lens 7 collects in the y direction perpendicular to the x direction on the cross section. Has optical performance. The focal distance in the x direction of the first cylindrical lens 6 and f _x, the focal length of the y direction of the second cylindrical lens 7, f _y. Further, as shown in FIG. 2, the distance between the monitor position 5 and the reference position 10 is L, the distance between the first cylindrical lens 6 and the monitor position 5 is L _ax, and the first cylindrical lens The distance between the second cylindrical lens 7 and the reference position 10 is L _bx , the distance between the second cylindrical lens 7 and the monitor position 5 is _Lay, and the distance between the second cylindrical lens 7 and the reference position 10. Is L _by . Using these distances, the first cylindrical lens 6 and the second cylindrical lens 7 are arranged so as to satisfy an imaging relationship that satisfies the imaging conditions of the following formulas (1) and (2).

Further, from the imaging conditions shown in the formulas (1) and (2), the beam diameters in the x direction and the y direction at the reference position 10 are as shown in the following formulas (3) and (4). each beam diameter at 5 is determined M _x magnification and M _y times become so.

  However, the following formula (5) is established.

FIG. 3 is a diagram illustrating a beam shape at the monitor position 5 in the beam shaping apparatus 100 according to the first embodiment. FIG. 4 is a diagram illustrating a beam shape at the reference position 10 in the beam shaping apparatus 100 according to the first embodiment. The ellipticity of the beam shape in FIG. 3 is k = φ _x / φ _y , and the ellipticity of the beam shape in FIG. 4 is k ₀ = φ _0x / φ _0y . φ _x and φ _0x are diameters in the x direction, respectively, and φ _y and φ _0y are diameters in the y direction, respectively.

It is assumed that the optical design is such that the beam shape at the reference position 10 is a circle with an ellipticity k ₀ = 1 and a diameter φ ₀ = 1.0 mm. Assuming that the beam shape at the monitor position 5 has a diameter φ _x = 0.12 mm in the _x direction and a diameter φ _y = 0.16 mm in the y direction, the beam shape at the monitor position 5 has an ellipticity k = 0.75 ( = 0.12 / 0.16). Then, in order to make the beam shape at the reference position 10 a circle having an ellipticity k ₀ = 1 and a diameter φ ₀ = 1.0 mm as described above, the magnifications in the x direction and the y direction are respectively M _x = 1 / 0.12 = 8.33 and M _y = 1 / 0.16 = 6.25. Furthermore, it is assumed that the distance L between the monitor position 5 and the reference position 10 is 800 mm.

The value of _M x, _{M y} and L shown in above, by using the condition of Equation (5) from equation (1) described _{above, f x = 76.5mm, f y} = 95.1mm, L ax = _85.7mm, L ay = 110.3mm is obtained, the focal length _f x, the arrangement of the _{f y} a first cylindrical lens 6 and the second cylindrical lens 7 is uniquely determined. A first cylindrical lens 6 and the second cylindrical lens 7, each having the focal length f _x and f _y, arranged as shown in FIG. 1 as the monitor position 5 becomes the L _ax and L _ay away Thus, a beam transmission system is constructed. That is, the beam shaping device 100 is configured to move the moving mechanism 12 based on the beam shape at the monitor position 5 and the target beam shape at the reference position 10 so that the monitor position 5 and the reference position 10 satisfy the imaging condition. , 13, 14 are controlled.

Here, it is assumed that the state of the laser oscillator 1 fluctuates with time and the beam diameter at the monitor position 5 changes as the characteristics of the laser beam 11 change. Changes in the beam diameter at the monitor position 5 can be detected by the beam shape monitor 4. In the beam shaping apparatus 100 used for laser processing, even if the beam shape at the monitor position 5 changes to the diameter φ ′ _{x in the x} direction and the diameter φ ′ _y in the y direction, the laser beam is processed in order to make the processing result constant. Regardless of the change of the light 11, it is desirable to maintain the aspect ratio of the beam shape at the reference position 10, that is, the ellipticity.

FIG. 5 is a diagram illustrating another positional relationship of the optical system between the monitor position 5 and the reference position 10 in the beam shaping apparatus 100 according to the first embodiment. 5, since the first cylindrical lens 6 and the second cylindrical lens 7 is not changed, the focus in the y-direction focal length f _x and the second cylindrical lens 7 in the x direction of the first cylindrical lens 6 the distance f _y is no change, the same as in FIG. Therefore, FIG. 5 is different from FIG. 2 in the arrangement of the monitor position 5, the reference position 10, the first cylindrical lens 6, and the second cylindrical lens 7, but the rest is the same.

In FIG. 5, the distance between the monitor position 5 and the reference position 10 is L ′, the distance between the first cylindrical lens 6 and the monitor position 5 is L ′ _ax, and the first cylindrical lens 6 and The distance between the second cylindrical lens 7 and the reference position 10 is L ′ _bx , the distance between the second cylindrical lens 7 and the monitor position 5 is L ′ _ay, and the distance between the second cylindrical lens 7 and the reference position 10. Is L' _by . In order to maintain the imaging conditions between the monitor position 5 and the reference position 10, the following formulas (6) to (10) need to be satisfied.

  However, the following formula (10) is established.

  Furthermore, in order to keep the ellipticity of the beam shape at the reference position 10 constant before and after beam fluctuation, the following formula (11) needs to be satisfied.

Between the new positions L ′ _ax , L ′ _ay and the monitor position 5 and the reference position 10 of the first cylindrical lens 6 and the second cylindrical lens 7 that simultaneously satisfy the above-described mathematical expressions (6) to (11). The distance L ′ can be uniquely determined.

As an example, the state of the laser oscillator 1 fluctuates with time, and the ellipticity k of the beam shape at the monitor position 5 is the diameter φ ′ _x = 0.14 mm in the x direction and the diameter φ ′ _y = 0.19 mm in the y direction. It is assumed that the elliptical shape changes to “= φ” _x / φ ′ _y = 0.74. Since the first cylindrical lens 6 and the second cylindrical lens 7 are not exchanged, f _x = 76.5 mm and f _y = 95.1 mm remain fixed. The imaging magnification from the monitor position 5 to the reference position 10 fluctuates to M ′ _x = 1 / 0.14 = 6.95 and M ′ _y = 1 / 0.19 = 5.12. In this case, according to Equation (6) to Equation (11), L ′ _ax = 87.5 mm, L ′ _ay = 113.7 mm, and L ′ = 695.8 mm, the beam shape at the reference position 10 The ellipticity can be maintained at 1. However, the beam diameter at the reference position 10 changes to φ ′ ₀ = 0.97 mm. If the ellipticity at the reference position 10 can be set to a target value, the beam diameter can be adjusted by easily correcting with the optical system 15 provided after the reference position 10.

By moving the moving mechanism 12 of the first cylindrical lens 6 to the reference position 10 side by 1.8 mm on the optical path, L _ax = 85.7 mm in FIG. 2 is changed to L ′ _ax = 87.5 mm in FIG. be able to. By moving the moving mechanism 13 of the second cylindrical lens 7 to the side of 3.4mm by reference position 10 on the optical path, and L _'ay = 113.7mm in FIG 5 _L ay = _110.3mm in FIG can do. In order to reduce the distance between the monitor position 5 and the reference position 10 by 104.2 mm, the moving mechanism 14 of the folding mirrors 8 and 9 in FIG. 1 is moved by 52.1 mm to the first cylindrical lens 6 and the second cylindrical lens. By approaching the lens 7 side, L = 800 mm in FIG. 2 can be changed to L ′ = 695.8 mm in FIG. That is, the optical path length between the monitor position 5 and the reference position 10 can be changed by the bending mirrors 8 and 9 and the moving mechanism 14.

  As described above, according to the beam shaping apparatus 100 according to the first embodiment, even if the state of the laser oscillator 1 fluctuates and the beam characteristics change, the beam shape change at the monitor position 5 is detected. By detecting at, the ellipticity of the beam shape at the reference position 10 can be maintained at a constant value without replacing the optical element without the need for adjustment by the user.

  Further, according to the beam shaping apparatus 100 according to the first embodiment, the beam shape at the reference position 10 can be changed to an arbitrary ellipticity by changing the values of the mathematical expressions (3) and (4). It is. Furthermore, it is possible to automatically control the moving mechanisms 12, 13, and 14 according to the change of the beam diameter at the monitor position 5, and to control the ellipticity of the beam shape at the reference position 10 in real time. That is, according to the change in the beam shape at the monitor position 5, the positions of the first cylindrical lens 6 and the second cylindrical lens 7 and the optical path length from the monitor position 5 to the reference position 10 satisfy Expression (11). Thus, the beam shape at the reference position 10 can be adjusted to the target ellipticity by uniquely adjusting while maintaining the imaging conditions between the monitor position 5 and the reference position 10.

  Further, according to the beam shaping apparatus 100 according to the first embodiment, the reflected light of the partial reflection mirror 3 is used for detecting the beam shape at the monitor position 5, but transmitted light may be used, or the monitor position may be used. The beam shape at the monitor position 5 may be estimated by measuring the beam on the beam traveling direction side of 5.

Embodiment 2. FIG.
FIG. 6 is a configuration diagram of the beam shaping device 200 according to the second exemplary embodiment of the present invention. In the beam shaping apparatus 200 according to the second embodiment, a movement capable of moving the optical system 15 on the optical axis instead of the movement mechanism 14 being removed from the beam shaping apparatus 100 according to the first embodiment. A mechanism 16 is added. Then, the reference position 10 fixed in the beam shaping device 100 is changed to the reference position 17 that moves along the optical axis in the beam shaping device 200.

  The configuration of the beam shaping device 200 other than the above is the same as that of the beam shaping device 100, and a description thereof will be omitted. That is, in the beam shaping apparatus 200 according to the second embodiment, the reference position 17 is moved along the optical axis by moving the optical system 15 along the optical axis, and the monitor position 5 and the reference position 17 are moved. The distance between can be changed. That is, it can be considered that the reference position 17 moves along the optical axis by moving the optical system 15.

  In the beam shaping apparatus 200 according to the second embodiment, the laser beam 11 that has passed through the two bending mirrors 8 and 9 reaches the reference position 17 and then moves on the optical axis 15 with an optical system 15 having a moving mechanism 16. Via.

In the beam shaping apparatus 200 according to the second embodiment, when the state of the laser oscillator 1 fluctuates with time and the characteristics of the laser light 11 change, the beam shape monitor 4 detects the change in the beam shape and the first embodiment. As described above, the new positions L ′ _ax , L ′ _ay and the monitor position 5 of the first cylindrical lens 6 and the second cylindrical lens 7 and the reference position so as to satisfy the expressions (6) to (11) A distance L ′ from the position 17 is determined.

In the beam shaping device 200, the first cylindrical lens 6 and the second cylindrical lens 7 are moved to new positions L ′ _ax and L ′ _ay by driving the moving mechanisms 12 and 13 as in the first embodiment. Move. However, unlike the first embodiment, the distance L ′ between the monitor position 5 and the reference position 17 is different from that of the first embodiment by driving the moving mechanism 16 of the optical system 15 arranged behind the reference position 17. It adjusts by moving 17 itself on an optical axis. Thereby, the beam shape at the reference position 17 can be maintained at the target ellipticity.

  According to the beam shaping apparatus 200 according to the second embodiment, the distance between the monitor position 5 and the reference position 17 is changed without the moving mechanism 14 provided in the beam shaping apparatus 100 according to the first embodiment. It becomes possible to do. Further, since the moving mechanism 14 is not required, it is possible to reduce the size by constructing a linear optical system by omitting the two folding mirrors 8 and 9.

  Also by the beam shaping apparatus 200 according to the second embodiment, the positions of the first cylindrical lens 6 and the second cylindrical lens 7 and the positions from the monitor position 5 to the reference position 17 are changed according to the change in the beam shape at the monitor position 5. The optical path length is uniquely adjusted while maintaining the imaging conditions between the monitor position 5 and the reference position 17, and the beam shape at the reference position 17 can be adjusted to the target ellipticity.

Embodiment 3 FIG.
FIG. 7 is a configuration diagram of a beam shaping device 300 according to the third embodiment of the present invention. In the beam shaping apparatus 300 according to the third embodiment, the optical system 15 of the beam shaping apparatus 100 according to the first embodiment is configured by the beam expander 18 in which the expansion ratio of the beam diameter of the laser light 11 is variable. . The configuration of the beam shaping device 300 other than the beam expander 18 is the same as that of the beam shaping device 100, and a description thereof will be omitted.

  In the beam shaping apparatus 300 according to the third embodiment, the optical system is arranged so that the beam of the laser light 11 that has passed through the reference position 10 enters the beam expander 18.

  Also in the beam shaping apparatus 300 according to the third embodiment, when the characteristics of the laser beam 11 from the laser oscillator 1 change, the beam shape detected by the beam shape monitor 4 is changed, as described in the first embodiment. The beam mechanisms at the reference position 10 are adjusted to the target ellipticity by driving the moving mechanisms 12, 13, and 14 so as to satisfy the formula (6) to the formula (11). However, when the characteristics of the laser beam 11 change, the beam diameter at the adjusted reference position 10 corresponding to the change in characteristics changes.

In the numerical example shown in the first embodiment, before the characteristic of the laser beam 11 is changed, a beam having a circular shape with a diameter φ ₀ = 1.0 mm and an ellipticity = 1 at the reference position 10 is changed in beam characteristics. After the adjustment according to the above, it changed to a circular beam having a diameter φ ′ ₀ = 0.97 mm while maintaining the ellipticity = 1. This variation in beam diameter is also a value analytically derived from Equation (6) to Equation (11). Therefore, in the case of an optical system that is desired to match before and after adjustment including the beam diameter in addition to the ellipticity, the beam diameter enlargement ratio of the adjusted beam expander 18 is 3% (= (1.0−0.97). ) /0.97) increase.

  According to the beam shaping apparatus 300 according to the third embodiment, the positions of the first cylindrical lens 6 and the second cylindrical lens 7 and the monitor position 5 to the reference position 10 according to the change in the beam shape at the monitor position 5. Can be adjusted to a target ellipticity with the beam shape at the reference position 10 being uniquely adjusted while maintaining the imaging conditions at the monitor position 5 and the reference position 10. Further, by using the beam expander 18, the beam diameter before and after the adjustment according to the beam characteristic fluctuation can be corrected and made constant.

Embodiment 4 FIG.
FIG. 8 is a configuration diagram of a beam shaping device 400 according to the fourth embodiment of the present invention. In the beam shaping apparatus 400 according to the fourth embodiment, the optical system 15 of the beam shaping apparatus 200 according to the second embodiment is configured by the beam expander 18 having a variable magnification, and the beam expander 18 on the optical axis. A moving mechanism 19 capable of moving the panda 18 is provided. That is, the optical system 15 and the moving mechanism 16 of the beam shaping device 200 are replaced with the beam expander 18 and the moving mechanism 19, and the configuration of the other beam shaping device 400 is the same as that of the beam shaping device 200. Omitted.

  Also in the beam shaping device 400, the reference position 17 is moved along the optical axis by moving the beam expander 18 along the optical axis, and the distance between the monitor position 5 and the reference position 17 is changed. Can do.

  In the beam shaping device 400 according to the fourth embodiment, the laser beam 11 that has passed through the two bending mirrors 8 and 9 reaches the reference position 17 and then moves on the optical axis. 18 via.

In the beam shaping device 400 according to the fourth embodiment, when the state of the laser oscillator 1 fluctuates over time and the characteristics of the laser light 11 change, the beam shape monitor 4 detects the change in the beam shape and the first embodiment. As described above, the new positions L ′ _ax , L ′ _ay and the monitor position 5 of the first cylindrical lens 6 and the second cylindrical lens 7 and the reference position so as to satisfy the expressions (6) to (11) A distance L ′ from the position 17 is determined.

In the beam shaping device 400, the first cylindrical lens 6 and the second cylindrical lens 7 are moved to new positions L ′ _ax and L ′ _ay by driving the moving mechanisms 12 and 13 as in the first embodiment. Move. However, the distance L ′ between the monitor position 5 and the reference position 17 is determined by driving the moving mechanism 19 of the beam expander 18 disposed behind the reference position 17 as in the second embodiment. The position 17 itself is adjusted by moving on the optical axis. Thereby, the beam shape at the reference position 17 can be maintained at the target ellipticity.

  According to the beam shaping device 400 according to the fourth embodiment, the monitor position 5 can be obtained without the moving mechanism 14 provided in the beam shaping device 100 according to the first embodiment or the beam shaping device 300 according to the third embodiment. And the reference position 17 can be changed. Further, since the moving mechanism 14 becomes unnecessary, it is possible to construct a linear optical system by omitting the two folding mirrors 8 and 9.

  Also in the beam shaping device 400 according to the fourth embodiment, the change in the beam diameter at the reference position 17 before and after the adjustment according to the beam characteristic variation can be analytically derived from the formula (6) to the formula (11). Similarly to the beam shaping device 300 according to the third embodiment, by adjusting the magnification rate of the beam expander 18, not only the ellipticity before and after the adjustment but also the beam diameter can be kept constant.

  According to the beam shaping device 400 according to the fourth embodiment, the positions of the first cylindrical lens 6 and the second cylindrical lens 7 and the monitor position 5 to the reference position 17 according to the change in the beam shape at the monitor position 5. Can be adjusted to the target ellipticity with the beam shape at the reference position 17 being uniquely adjusted while maintaining the imaging conditions of the monitor position 5 and the reference position 17. Further, by using the beam expander 18, it is possible to make the beam diameter before and after adjustment according to the beam characteristic fluctuation constant.

  The configuration described in the above embodiment shows an example of the contents of the present invention, and can be combined with another known technique, and can be combined with other configurations without departing from the gist of the present invention. It is also possible to omit or change the part.

  DESCRIPTION OF SYMBOLS 1 Laser oscillator, 2 Transmission optical system, 3 Partial reflection mirror, 4 Beam shape monitor, 5 Monitor position, 6 1st cylindrical lens, 7 2nd cylindrical lens, 8,9 Bending mirror, 10,17 Reference position, 11 Laser beam, 12, 13, 14, 16, 19 moving mechanism, 15 optical system, 18 beam expander, 100, 200, 300, 400 beam shaping device.

Claims (4)

Measuring means for measuring the beam shape of the laser beam at a monitor position on the optical axis;
A first cylindrical lens that transmits the laser light having passed through the monitor position;
A first cylindrical lens and a second cylindrical lens that are orthogonal to each other in a condensing direction and transmit the laser light that has passed through the first cylindrical lens;
A bending mirror that changes a traveling direction of the laser light that has passed through the second cylindrical lens;
A moving mechanism for moving the first and second cylindrical lenses and the folding mirror in the direction of the optical axis,
With
Based on the beam shape at the monitor position, the moving mechanism is controlled so that the monitor position and the reference position through which the laser light passes after the traveling direction is changed by the bending mirror satisfy the imaging condition. A beam shaping device characterized by that. Measuring means for measuring the beam shape of the laser beam at a monitor position on the optical axis;
A first cylindrical lens that transmits the laser light having passed through the monitor position;
A first cylindrical lens and a second cylindrical lens that are orthogonal to each other in a condensing direction and transmit the laser light that has passed through the first cylindrical lens;
An optical system through which the laser light passes through the second cylindrical lens;
A moving mechanism for moving each of the first and second cylindrical lenses and the optical system in the direction of the optical axis;
With
Controlling the moving mechanism based on the beam shape at the monitor position so that the monitor position and a reference position located between the second cylindrical lens and the optical system satisfy an imaging condition. A beam shaping device characterized by the above. The beam shaping apparatus according to claim 1, further comprising a beam expander on which the laser light having passed through the reference position is incident and a magnification ratio of a beam diameter of the laser light is variable. The beam shaping apparatus according to claim 2, wherein the optical system is a beam expander in which an enlargement ratio of a beam diameter of the laser light is variable.

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