Laser device and method for material processing by means of pulsed laser beam

Abstract

The present application relates to a laser device for material processing by means of a pulsed laser beam, comprising: a laser source for generating a pulsed laser beam; the focusing device is used for focusing the laser beam onto the workpiece; a stepped device comprising at least one stage, the stepped device configured to transmit the laser beam, the stepped device being arranged downstream of or within the laser source with respect to a propagation direction of the laser beam, the stepped device is configured to delay a first portion of the laser beam passing through the stage relative to a second portion of the laser beam passing outside the stage, the stepped device being configured to adjust a power ratio between the first portion of the laser beam and the second portion of the laser beam. The invention also relates to a corresponding method for processing a material by means of a pulsed laser beam. The device has the advantages that the pre-pulse and the post-pulse as well as the power ratio between the pre-pulse and the post-pulse can be realized in a simple mode.

Description

Technical Field

[0001] The present invention relates to a laser apparatus for material processing by means of a pulsed laser beam having the features of claim 1, and a method for material processing by means of a pulsed laser beam having the features of claim 15. Background Technology

[0002] Laser material processing uses laser beams to cut, weld, or modify materials with high precision. This technique minimizes heat-affected zones and is widely used in modern manufacturing for complex and efficient material processing. Typically, pulsed laser beams with high repetition rates are used.

[0003] The drawback is that generating a laser beam with the desired repetition rate and pulses is complex, inflexible, and limited by the characteristics of the laser source used. Summary of the Invention

[0004] Therefore, the objective of this invention is to provide a laser apparatus and method for processing materials by means of a pulsed laser beam, wherein the above-mentioned disadvantages are eliminated.

[0005] The above tasks are accomplished by means of a laser device having the features of claim 1. The laser device is configured for material processing using a pulsed laser beam. Material processing may involve laser cutting, laser welding, laser ablation, laser surface texturing, and / or laser volumetric modification.

[0006] The laser device includes a laser source, a focusing device, and a stepped device. The laser source is configured to generate a pulsed laser beam. The focusing device is configured to focus the laser beam onto a workpiece. The stepped device includes at least one stage. The stepped device is configured to transmit the laser beam. The stepped device is arranged downstream of the laser source or within the laser source relative to the propagation direction of the laser beam. The laser source may include a seed laser. The laser device may include at least one amplifier. The amplifier may include one or more amplifier stages. The stepped device may be arranged between the seed laser and the amplifier. The stepped device may be arranged upstream of the focusing device relative to the propagation direction of the laser beam. The stepped device may be arranged between the laser source and the focusing device. The stepped device is configured to delay the first portion of the laser beam passing through a stage relative to a second portion outside the laser beam passing through stage. The stepped device is configured to adjust the power ratio between the first portion and the second portion of the laser beam.

[0007] This allows for the simple implementation of pre-pulse and post-pulse, as well as the power ratio between them. No additional and complex optics, gratings, spatial light modulators, optoelectronic devices, acousto-optic devices, or prisms are required. The stepped device can also be easily implemented within existing laser systems. Efficient and robust generation of time-dependent pulses, particularly at picosecond resolution, is possible. The stepped device is compatible with most optical systems, especially picosecond and / or femtosecond laser sources. Time-customizable laser pulses can be generated. The designable intensity function can be implemented as a function of time. The extreme flexibility in designing custom pulse sequences is achieved. Therefore, this laser device is suitable for a wide range of applications.

[0008] A stepped device may include a cross-section divided into several (at least two) levels, which are defined sub-regions. The method of dividing the cross-section into levels or sub-regions is not limited. The cross-section may be multi-striped, annular, sector-shaped, or square. Each level or sub-region may have at least one planar surface. Levels may result in different thicknesses or heights of the cross-section of the stepped device. At least one level or sub-region may be designed based on a gas, particularly air (e.g., a gas chamber). At least one level or sub-region may be surrounded by a gas, particularly air.

[0009] Stepped devices can be integrated into lenses or diffractive optical elements (DOEs). A typical example is a Fresnel lens, where each ring has a different optical path. Each ring can represent a stage of the stepped device. Material processing can be further optimized using stepped devices designed as Fresnel lenses, and particularly using a 30 fs laser source.

[0010] The focusing device can be implemented in a stepped device, for example, where the stepped device is designed as a lens, particularly a Fresnel lens. The focusing device and the stepped device can be designed as a single optical element. It is also conceivable that the focusing device and the stepped device can be designed as separate devices or elements. The focusing device can be designed as a reflective focusing unit, particularly as an off-axis mirror.

[0011] Stepped devices, especially steps, may include anti-reflective coatings.

[0012] Depending on the implementation of the laser device, the laser source may include an ultrashort laser. The laser source can be designed as an ultrashort laser.

[0013] In this way, laser sources can be implemented in a simple manner.

[0014] According to the implementation of the laser device, the laser source can be configured to generate a laser beam with a maximum power of 1 GW (gigawatt), particularly a maximum power of 100 MW (megawatt).

[0015] This ensures that the stepped device is not damaged by the laser beam, especially when the laser beam passes through the stepped device.

[0016] According to the implementation of the laser device, the laser source can be configured to generate a laser beam with a pulse duration in the range of 100 fs (femtoseconds) to 30 ps (picoseconds), particularly in the range of 25 fs to 30 ps.

[0017] This enables the provision of optimal parameters for material processing, allowing for further optimization of the process.

[0018] According to the implementation of the laser device, the laser source can be configured to generate a laser beam with a center wavelength in the range of 200 nm to 3000 nm, particularly in the range of 200 nm to 1030 nm.

[0019] This enables the provision of optimal parameters for material processing, allowing for further optimization of the process.

[0020] According to the implementation of the laser device, the laser source can be configured to generate a laser beam with a beam diameter in the range of 5 mm to 100 mm, particularly in the range of 2.5 mm to 50 mm.

[0021] This enables the provision of optimal parameters for material processing, allowing for further optimization of the process.

[0022] According to the implementation of the laser device, the stage can be movable perpendicular to the propagation direction of the laser beam. Alternatively or additionally, it is conceivable that the stage can be movable along the propagation direction of the laser beam.

[0023] This makes it possible to adjust the stepped device in a simple way.

[0024] According to the implementation of the laser device, the stepped device can be configured to adjust the power ratio between the first part and the second part of the laser beam by moving a stage perpendicular to the propagation direction of the laser beam.

[0025] This allows for a simple adjustment of the power ratio between the first and second portions of the laser beam.

[0026] According to embodiments of the laser device, the stepped device can be configured to adjust the power of the second portion of the laser beam within a range of 1% to 50% of the total power of the laser beam. Therefore, the stepped device can be configured to adjust the power of the first portion of the laser beam within a range of 49% to 99% of the total power of the laser beam (and vice versa). This ratio can be achieved by spatially partially placing the stepped device, particularly the stages, within the laser beam (original beam). The area of ​​the stages of the stepped device irradiated by the laser beam (original beam) corresponds to the power ratio of the delayed pulses.

[0027] This enables the implementation of weak pre-pulses and strong post-pulses in a simple manner, and the material processing is further optimized.

[0028] According to the implementation of the laser device, the stage can be rotatable about a rotation axis perpendicular to the propagation direction of the laser beam. Alternatively or additionally, it is conceivable that the stage can be rotatable about the propagation direction of the laser beam.

[0029] This makes it possible to adjust the length of the optical path of the first part of the laser beam through the stage in a simple way.

[0030] According to the implementation of the laser device, the stepped device can be configured to adjust the delay between the first part and the second part of the laser beam by rotating the stages along the axis of rotation.

[0031] This makes it possible to adjust the delay between the first part and the second part of the laser beam in a simple way.

[0032] It is conceivable that the stage can be moved and / or rotated via a movable and / or rotating stepped device. The laser device may include an axis system for moving and / or rotating the stepped device and / or the stage.

[0033] According to the implementation of the laser device, the stepped device can be configured to delay the first part of the laser beam in the range of 100 fs to 100 ps relative to the second part of the laser beam. For example, a step designed with a 1 mm glass plate (refractive index n = 1.5) produces a delay of 1.7 ps relative to a vacuum.

[0034] This enables the provision of optimal parameters for material processing, allowing for further optimization of the process.

[0035] According to embodiments of the laser device, the stage can be designed as a glass plate, particularly a glass plate with a thickness ranging from 0.1 mm to 60 mm. It is conceivable that the thickness of the stage can be adjustable. It is also conceivable that the thickness of the stage can be adjusted by changing a stage having a first thickness to a stage having a second thickness different from the first thickness. The stage can be designed as a glass plate and / or a transparent plate. The stage can be made of fused silica or any other power-resistant transparent material.

[0036] This makes it possible to achieve the level in a simple way, and the material processing is further optimized.

[0037] Assuming the glass has a refractive index of 1.5, a stage designed as a 2mm thick glass plate would produce a 3ps delay compared to air. It is conceivable that an additional (second) stage of the stepped device could be designed as air.

[0038] According to an embodiment of the laser device, the laser device may include an optical device for shaping the laser beam.

[0039] This allows the laser beam to be adjusted and / or shaped as needed in a simple manner.

[0040] Laser equipment may include control units for controlling the laser equipment, stepped devices, stages, axis systems, and / or laser sources. The control unit may be configured to operate the laser equipment, particularly the laser source, in an on-demand pulse mode.

[0041] The above task is accomplished by means of a method for material processing by means of a pulsed laser beam, having the features of claim 15.

[0042] The method includes the following steps:

[0043] - Generates a pulsed laser beam.

[0044] -Focus the laser beam onto the workpiece.

[0045] - Delay the first part of the laser beam relative to the second part of the laser beam.

[0046] - Adjust the power ratio between the first part of the laser beam and the second part of the laser beam.

[0047] - Perform this method using a laser device as described above.

[0048] For the advantages that can be achieved using this method, refer to relevant reviews on laser devices. The measures described in the laser device description and / or those explained below can be used to further design this method. Attached Figure Description

[0049] Further features, details, and advantages of the invention will become apparent from the wording of the claims and from the following description of embodiments with reference to the accompanying drawings. It is shown that:

[0050] Figure 1 A schematic diagram of a laser device used for material processing using a pulsed laser beam.

[0051] Figure 2 According to the schematic diagram of the stepped device of the laser equipment in the second embodiment,

[0052] Figure 3 A schematic diagram of the stepped device of the laser device according to the third embodiment, and

[0053] Figure 4 Schematic diagrams of four other embodiments of the stepped device for laser equipment. Detailed Implementation

[0054] Figure 1 A schematic diagram of a laser device 10 is shown. The laser device 10 is configured for material processing using a pulsed laser beam 12.

[0055] The laser device 10 includes a laser source 14, a focusing device 16, and a stepped device 20. The laser source 14 is configured to generate a pulsed laser beam 12. The focusing device 16 is configured to focus the laser beam 12 onto a workpiece 18.

[0056] The stepped device 20 includes at least one stage 22. The stepped device 20 is configured to transmit a laser beam 12. The stepped device 20 is arranged downstream of the laser source 14 relative to the propagation direction 24 of the laser beam 12. In this example, the stepped device 20 is arranged between the laser source 14 and the focusing device 16. The stepped device 20 is configured to delay the first portion 26 of the laser beam 12 passing through the stage 22 relative to a second portion 28 outside the passing stage 22. The stepped device 20 is configured to adjust the power ratio between the first portion 26 and the second portion 28 of the laser beam 12.

[0057] In this example, the propagation direction 24 corresponds to the z-direction and from Figure 1 Left-to-right orientation in the middle.

[0058] Laser source 14 may include an ultrashort laser. Laser source 14 may be designed as an ultrashort laser.

[0059] The laser source 14 can be configured to generate a laser beam 12 with a maximum power of 1 GW, particularly a maximum power of 100 MW.

[0060] The laser source 14 can be configured to generate a laser beam 12 with a pulse duration in the range of 100 fs to 30 ps, ​​particularly in the range of 25 fs to 30 ps.

[0061] The laser source 14 can be configured to generate a laser beam 12 with a center wavelength in the range of 200 nm to 3000 nm, particularly in the range of 200 nm to 1030 nm.

[0062] The laser source 14 can be configured to generate a laser beam 12 with a beam diameter in the range of 5 mm to 100 mm, particularly in the range of 2.5 mm to 50 mm.

[0063] Stage 22 can be moved perpendicular to the propagation direction 24 of the laser beam 12. In this example, stage 22 is movable along the x-direction 34. The x-direction 34 is oriented perpendicular to the propagation direction 24 of the laser beam 12 and from... Figure 1 Extending from bottom to top.

[0064] The stepped device 20 can be configured to adjust the power ratio between the first portion 26 and the second portion 28 of the laser beam 12 by moving the stage 22 perpendicular to the propagation direction 24 of the laser beam 12, particularly along the x-direction 34. For example, if the stage 22 is moved into the laser beam 12 in such a way that half of the laser beam is divided into the first portion 26 and half of the laser beam is divided into the second portion 28, then the power of the laser beam 12 can be divided 50% between the two portions in each case. The desired power ratio can be set by further moving the stage 22 into or out of the laser beam 12.

[0065] It can be envisioned that the movement of stage 22 can be achieved by moving the entire stepped device 20, particularly along the x-direction 34.

[0066] The stepped device 20 can be configured to adjust the power of the second portion 28 of the laser beam 12 within a range of 1% to 50% of the total power of the laser beam 12. Therefore, the stepped device 20 can be configured to adjust the power of the first portion 26 of the laser beam 12 within a range of 49% to 99% of the total power of the laser beam 12 (and vice versa).

[0067] Stage 22 is rotatable about a rotation axis 30 perpendicular to the propagation direction 24 of the laser beam 12. In this example, the rotation axis 30 is from... Figure 1 The orientation is from bottom to top. It can also be envisioned that the rotation axis 30 is orthogonal to the propagation direction 24 and... Figure 1 The axes of rotation shown are orthogonally oriented, that is, from Figure 1 The image plane is highlighted.

[0068] The stepped device 20 can be configured to adjust the delay between the first portion 26 and the second portion 28 of the laser beam 12 by rotating the stage 22 about the rotation axis 30.

[0069] It can be envisioned that the rotation of stage 22 can be achieved by rotating the entire stepped device 20, especially around the rotation axis 30.

[0070] The stepped device 20 can be configured to delay the first portion 26 of the laser beam 12 in the range of 100 fs to 100 ps relative to the second portion 28 of the laser beam 12.

[0071] Grade 22 can be designed as a glass plate. The thickness of Grade 22 can range from 0.1 mm to 60 mm.

[0072] In this example, a (e.g., weak) prepulse can be generated using the second portion 28 of the laser beam 12. A (e.g., strong) afterpulse can be generated using the first portion 26 of the laser beam 12.

[0073] The laser device 10 may include an optical device 32 for shaping the laser beam 12.

[0074] In this example, in addition to stage 22, the stepped device 20 also includes a second stage 36. The second stage 36 can be designed similarly to, and in particular identically to, stage 22. It is also conceivable that the second stage 36 could be designed as a gas, such as air. In this example, the only difference between stage 22 and the second stage 36 is that their lengths along the x-direction 34 differ.

[0075] Stage 22 and stage 36 can be securely connected together. This allows stage 22 and stage 36 to move and / or rotate together. This makes the stepped device 20 easy to operate.

[0076] It is also conceivable that stage 22 and the second stage 36 can move and / or rotate independently of each other. This would increase the flexibility and adjustment options of the stepped device 20.

[0077] In this example, a pulsed laser beam 12 is generated by a laser source 14. The laser beam 12 propagates along a propagation direction 24 and is transmitted through a stepped device 20. A first portion 26 of the laser beam 12 passes through stage 22 and the second stage 36. A second portion 28 of the laser beam 12 passes only through the second stage 36. This creates a (time) delay and power distribution between the first portion 26 and the second portion 28 of the laser beam 12. Subsequently, the laser beam 12, particularly the first portion 26 and the second portion 28, is shaped by an optical device and focused by a focusing device 16 onto a workpiece 18 for processing its material.

[0078] Figure 2 A schematic diagram of the stepped device 20 of the laser device 10 according to the second embodiment is shown.

[0079] In this example, the stepped device 20 and the focusing device 16 are designed as Fresnel lenses. In other words, the stepped device 20 and the focusing device 16 are designed as a single Fresnel lens (optical element). The thickness of the Fresnel lens can be 6 mm. In this example, stage 22 has a ring-shaped (circular) shape, and the second stage 36 has a circular shape.

[0080] In this example, the first portion 26 of the laser beam 12 passes through stage 22 and is focused onto the workpiece 18. The first portion 26 of the laser beam 12 has a cross-section corresponding to the shape of stage 22 (i.e., ring-shaped). The second portion 28 of the laser beam 12 passes through the second stage 36 and is focused onto the workpiece 18. The second portion 28 of the laser beam 12 has a cross-section corresponding to the shape of the second stage 36 (i.e., circular). This results in a (time) delay and power distribution between the first portion 26 and the second portion 28 of the laser beam 12.

[0081] Obviously, the stepped device 20 and focusing device 16, which are designed as Fresnel lenses in this example, can also have more than two stages, especially more than 10 stages, since Fresnel lenses typically have more than two rings, especially more than 10 rings.

[0082] Figure 3 A schematic diagram of the stepped device 20 of the laser device 10 according to the third embodiment is shown.

[0083] In this example, in addition to stage 22 and stage 36, the stepped device 20 also includes a third stage 38. The third stage 38 can be designed similarly to, and in particular identically to, stage 22 and / or stage 36. In this example, the only difference between stage 22, stage 36, and stage 38 is the length of the stage, the second stage, and the third stage along the x-direction 34.

[0084] The first portion 26 of laser beam 12 passes through stage 22, the second stage 36, and the third stage 38. The second portion 28 of laser beam 12 passes only through the second stage 36 and the third stage 38. The third portion 40 of laser beam 12 passes only through the third stage 38. This results in a (time) delay and power distribution between the first portion 26, the second portion 28, and the third portion 40 of laser beam 12.

[0085] In this example, the power distribution among the first portion 26, the second portion 28, and the third portion 40 of the laser beam 12 can be adjusted by moving the stage 22, the second stage 36, and / or the third stage 38 along the x-direction 34.

[0086] It can be envisioned that the movement of stage 22, the second stage 36 and / or the third stage can be achieved by moving the entire stepped device 20, particularly along the x-direction 34.

[0087] In this example, the delay between the first portion 26, the second portion 28, and the third portion 40 of the laser beam 12 can be adjusted by rotating the second stage 22, the second stage 36, and / or the third stage 38 about the rotation axis 30. In this example, the rotation axis 30 is oriented parallel to the x-direction 34.

[0088] It is conceivable that the rotation of stage 22, the second stage 36, and / or the third stage 38 can be achieved by rotating the entire stepped device 20, particularly about the rotation axis 30. The delay can be fine-tuned using rotation, as small angles affect the difference in optical path length.

[0089] Figure 4 Schematic diagrams of four additional embodiments of the stepped device 20 are shown. In each case, the stepped device 20 is shown as viewed in the propagation direction 24 of the laser beam 12. In this case, the propagation direction 24 is oriented to... Figure 4 In the image plane.

[0090] exist Figure 4 In the upper left corner, the stepped device 20 includes a stage 22, a second stage 36, and a third stage 38 (a total of three stages). Stages 22, 36, and 38 each have a circular shape with a different diameter. Stages 22, 36, and 38 are arranged coaxially with each other.

[0091] exist Figure 4 In the upper right corner, the stepped device 20 includes a stage 22, a second stage 36, and a third stage 38 (a total of three stages). Stage 22 and the second stage 36 each have different and, in this example, non-uniform shapes.

[0092] exist Figure 4 In the two embodiments shown at the top, the cross-sectional area of ​​the laser beam 12 covered by each stage 22, 36, 38 can be adjusted or changed by moving the stepped device 20, stage 22, second stage 36, and / or third stage 38 perpendicular to the propagation direction 24. In this way, the power ratio between the first portion 26, the second portion 28, and the third portion 40 of the laser beam 12 can be adjusted.

[0093] exist Figure 4 In the two embodiments shown at the top, the (time) delay between the first portion 26, the second portion 28, and the third portion 40 of the laser beam 12 can be adjusted by rotating the stepped device 20, stage 22, second stage 36, and / or third stage 38 perpendicular to the propagation direction 24, particularly about the x-direction 34.

[0094] exist Figure 4 In the lower left corner, the stepped device 20 includes step 22, second step 36, third step 38, and fourth step 42 (a total of four steps). Steps 22, 36, 38, and 42 are designed as stairs or steps oriented along the x-direction 34.

[0095] exist Figure 4In the lower right corner, the stepped device 20 includes stage 22, second stage 36, third stage 38, and fourth stage 42 (a total of four stages). The cross-section of the stepped device 20 is divided into four equal parts by stage 22, second stage 36, third stage 38, and fourth stage 42.

[0096] exist Figure 4 In the two embodiments shown at the bottom, the cross-sectional area of ​​the laser beam 12 covered by each stage 22, 36, 38, 42 can be adjusted or changed by moving the stepped device 20, stage 22, second stage 36, third stage 38, and / or fourth stage 42 perpendicular to the propagation direction 24. In this way, the power ratio between the first portion 26, the second portion 28, the third portion 40, and the fourth portion (passing only through the fourth stage 42) of the laser beam 12 can be adjusted.

[0097] exist Figure 4 In the two embodiments shown at the bottom, the time delay between the first portion 26, the second portion 28, the third portion 40, and the fourth portion of the laser beam 12 can be adjusted by rotating the stepped device 20, stage 22, second stage 36, third stage 38, and / or fourth stage 42 perpendicular to the propagation direction 24, particularly about the x-direction 34.

[0098] The following will refer to Figures 1 to 4 A method for processing materials using a pulsed laser beam 12 is described.

[0099] The method includes the following steps:

[0100] - Generate a pulsed laser beam 12. This can be achieved using a laser source 14.

[0101] - Focus the laser beam 12 onto the workpiece 18. This can be achieved using a focusing device 16.

[0102] - The first portion 26 of the laser beam 12 is delayed relative to the second portion 28 of the laser beam 12. This can be achieved using a stepped device 20.

[0103] - Adjust the power ratio between the first portion 26 and the second portion 28 of the laser beam 12. This can be achieved using a stepped device 20.

[0104] - This method is performed using the laser device 10 described above. The laser device 10 may be... Figure 1 The laser device 10 shown.

[0105] List of reference numerals

[0106] 10 laser devices

[0107] 12-pulse laser beam

[0108] 14 laser sources

[0109] 16 focusing devices

[0110] 18 workpieces

[0111] 20-step device

[0112] Level 22

[0113] 24 directions of dissemination

[0114] The first part of 26 laser beams

[0115] The second part of the 28 laser beams

[0116] 30 Rotation axis

[0117] 32 Optical Devices

[0118] 34X direction

[0119] 36 Level 2

[0120] 38 Level 3

[0121] The third part of the 40 laser beam

[0122] 42 Level 4

Claims

1. A laser device (10) for processing materials using a pulsed laser beam (12), said laser device comprising: - A laser source (14) for generating the pulsed laser beam (12), - A focusing device (16) is used to focus the laser beam (12) onto the workpiece (18). - A stepped device (20) comprising at least one stage (22), wherein the stepped device (20) is configured to transmit the laser beam (12), wherein the stepped device (20) is arranged downstream of or within the laser source (14) relative to the propagation direction (24) of the laser beam (12), wherein the stepped device (20) is configured to delay the first portion (26) of the laser beam (12) passing through the stage (22) relative to the second portion (28) of the laser beam (12) passing outside the stage (22), wherein the stepped device (20) is configured to adjust the power ratio between the first portion (26) and the second portion (28) of the laser beam (12).

2. The laser device (10) according to claim 1, characterized in that, The laser source (14) includes an ultrashort laser or is designed to be an ultrashort laser.

3. The laser device (10) according to claim 1 or 2, characterized in that, The laser source (14) is configured to generate a laser beam (12) with a maximum power of 1 GW, particularly a maximum power of 100 MW.

4. The laser device (10) according to any one of the preceding claims, characterized in that, The laser source (14) is configured to generate a laser beam (12) with a pulse duration in the range of 100 fs to 30 ps, ​​particularly in the range of 25 fs to 30 ps.

5. The laser device (10) according to any one of the preceding claims, characterized in that, The laser source (14) is configured to generate a laser beam (12) with a center wavelength in the range of 200 nm to 3000 nm, particularly in the range of 200 nm to 1030 nm.

6. The laser device (10) according to any one of the preceding claims, characterized in that, The laser source (14) is configured to generate a laser beam (12) with a beam diameter in the range of 5 mm to 100 mm, particularly in the range of 2.5 mm to 50 mm.

7. The laser device (10) according to any one of the preceding claims, characterized in that, The stage (22) is movable perpendicular to the propagation direction (24) of the laser beam (12).

8. The laser device (10) according to claim 7, characterized in that, The stepped device (20) is configured to adjust the power ratio between the first portion (26) and the second portion (28) of the laser beam (12) by moving the stage (22) perpendicular to the propagation direction (24) of the laser beam (12).

9. The laser device (10) according to any one of the preceding claims, characterized in that, The stepped device (20) is configured to adjust the power of the second portion (28) of the laser beam (12) within a range of 1% to 50% of the total power of the laser beam (12).

10. The laser device (10) according to any one of the preceding claims, characterized in that, The stage (22) is rotatable about a rotation axis (30) perpendicular to the propagation direction (24) of the laser beam (12).

11. The laser device (10) according to claim 10, characterized in that, The stepped device (20) is configured to adjust the delay between the first portion (26) and the second portion (28) of the laser beam (12) by rotating the stage (22) about the rotation axis (30).

12. The laser device (10) according to any one of the preceding claims, characterized in that, The stepped device (20) is configured to delay the first portion (26) of the laser beam (12) in the range of 100 fs to 100 ps relative to the second portion (28) of the laser beam (12).

13. The laser device (10) according to any one of the preceding claims, characterized in that, The stage (22) is designed as a glass plate, particularly a glass plate with a thickness in the range of 0.1 mm to 60 mm.

14. The laser device (10) according to any one of the preceding claims, characterized in that, The laser device (10) includes an optical device (32) for shaping the laser beam (12).

15. A method for processing materials using a pulsed laser beam (12), the method comprising the following steps: - Generate the pulsed laser beam (12); -Focus the laser beam (12) onto the workpiece (18); - Delay the first portion (26) of the laser beam (12) relative to the second portion (28) of the laser beam (12); - Adjust the power ratio between the first portion (26) and the second portion (28) of the laser beam (12); - The method is performed using the laser device (10) according to any one of the preceding claims.

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