Laser processing device

Abstract

A laser processing apparatus according to an embodiment may include a laser light source configured to emit a first laser light, a first optical system, a second optical system, a first wavefront sensor, a second wavefront sensor, and a processor, the first laser enters the first optical system and is emitted by the first optical system as second laser, the second laser enters the second optical system and is emitted by the second optical system as third laser, the first wavefront sensor is configured to measure first wavefront information of the second laser, and the second wavefront sensor is configured to measure second wavefront information of the third laser. The third laser light is reflected by the second wavefront sensor as fourth laser light, and the second wavefront sensor is configured to measure second wavefront information of the fourth laser light, and the processor is configured to calculate a wavefront aberration of the second optical system using the first wavefront information and the second wavefront information.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2024-0134606, filed on October 4, 2024, which is hereby incorporated by reference for all purposes as if fully set forth herein. TECHNICAL FIELD

[0003] The present disclosure relates to a laser processing apparatus configured to detect a wavefront aberration that can be generated by an optical system through which laser light passes, and to control an effect due to the wavefront aberration, thereby enabling a more precise laser processing process to be performed. BACKGROUND

[0004] Generally, a laser processing process refers to a process of processing a shape or a physical property of a surface of a workpiece by injecting a laser beam to the surface of the workpiece. The workpiece for a workpiece cutting apparatus can have many examples. For example, a wafer or a thin film glass substrate in the form of a thin film can be used as the workpiece. Also, the shape of the workpiece can be a two-dimensional planar shape, or can be a three-dimensional solid shape.

[0005] As examples of the laser processing process, a process of forming a pattern on a surface of a workpiece, a process of changing a property of a workpiece, a process of heating a workpiece using a laser and changing a shape of the workpiece, a process of cutting a workpiece using a laser beam, and the like can be cited.

[0006] Laser light emitted from a laser source can pass through an optical system and be incident on a workpiece. During the passage of the laser head through the optical system, a wavefront aberration due to the optical system can occur. In the case where the wavefront aberration occurs in the laser light passing through the optical system, the characteristics of the laser light can be distorted, thereby possibly causing a decrease in the quality of the laser light. SUMMARY

[0007] TECHNICAL PROBLEM

[0008] The present disclosure provides a laser processing apparatus configured to measure a wavefront aberration generated by an optical system through which laser light passes.

[0009] Also, the present disclosure provides a laser processing apparatus configured to measure a wavefront aberration generated by each optical system in laser light passing through a plurality of optical systems.

[0010] Also, the present disclosure provides a laser processing apparatus configured to measure a wavefront aberration of an optical system disposed opposite a workpiece.

[0011] Also, the present disclosure aims to provide a miniaturized laser processing apparatus by simplifying the configuration of a measurement apparatus that measures a wavefront aberration of an optical system.

[0012] Also, the present application aims to provide a laser processing apparatus configured to correct a characteristic of laser light distorted by an optical system by correcting a wavefront aberration of measured laser light.

[0013] Also, the present application aims to provide a laser processing apparatus configured to set laser light that has been corrected for a wavefront aberration as a standard light and intentionally reduce or increase a wavefront aberration to change a characteristic of the laser light.

[0014] Technical Solution

[0015] A laser processing apparatus according to an embodiment can include a laser source configured to emit first laser light, a first optical system, a second optical system, a first wavefront sensor configured to measure first wavefront information of the second laser light, a third laser light reflected by the second wavefront sensor as fourth laser light, and a second wavefront sensor configured to measure second wavefront information of the fourth laser light, and a processor configured to calculate a wavefront aberration of the second optical system using the first wavefront information and the second wavefront information.

[0016] The laser processing apparatus can further include a first optical member configured to cause the second laser light to be incident on the first wavefront sensor, and a second optical member configured to cause the fourth laser light to be incident on the second wavefront sensor.

[0017] A wavefront measurement position at which the first wavefront information is measured and a wavefront measurement position at which the second wavefront information is measured can be the same, and the wavefront measurement position can be disposed between the first optical member and the second optical member.

[0018] A 1-1 distance between the first optical member and the first wavefront sensor and a 1-2 distance between the first optical member and the wavefront measurement position can be the same, and a 2-1 distance between the second optical member and the second wavefront sensor and a 2-2 distance between the second optical member and the wavefront measurement position can be the same.

[0019] The first optical component and the second optical component can be a polarizing beam splitter (PBS), and the laser processing apparatus can further include a quarter-wave plate (QWP) disposed between the second optical component and the second optical system.

[0020] The laser processing apparatus can further include an optical component configured to split the second laser light into a 2-1 laser light and a 2-2 laser light, the 2-1 laser light being incident on the first wavefront sensor and the 2-2 laser light being incident on the second optical system, the optical component can cause the fourth laser light to be incident on the second wavefront sensor.

[0021] A wavefront measurement position can be disposed at a position where a 1-1 distance between the optical component and the first wavefront sensor and a 1-2 distance between the optical component and the wavefront measurement position are the same, the wavefront measurement position can be disposed between the optical component and the second optical system.

[0022] The second wavefront sensor can be disposed to be spaced apart from the wavefront measurement position by a third distance.

[0023] The processor can correct the second wavefront information according to the third distance based on a beam propagation method (BPM).

[0024] The optical component is a polarizing beam splitter, and

[0025] The laser processing apparatus can further include a quarter-wave plate disposed between the optical component and the second optical system.

[0026] The laser processing apparatus can further include an optical component and a third optical system, wherein the optical component is configured to split the second laser light into a 2-1 laser light and a 2-2 laser light, the 2-1 laser light being incident on the first wavefront sensor, the 2-2 laser light being incident on the second optical system, the third optical system being configured to emit the fourth laser light incident via the optical component as a fifth laser light incident on the second wavefront sensor.

[0027] A wavefront measurement position measuring the first wavefront information and a wavefront measurement position measuring the second wavefront information can be the same, the wavefront measurement position can be disposed between the optical component and the second optical system.

[0028] A first-1 distance between the optical member and the first wavefront sensor and a first-2 distance between the optical member and the wavefront measurement position can be the same, and third wavefront information of the fifth laser incident on the second wavefront sensor can be the same as second wavefront information of the fourth laser.

[0029] The optical member can be a polarization beam splitter, and

[0030] The laser processing apparatus can further include a quarter wave plate disposed between the optical member and the second optical system.

[0031] The third optical system can be a transmission optical system.

[0032] The laser processing apparatus can further include a spatial light modulator configured to modulate a characteristic of the first laser according to a wavefront aberration of the second optical system.

[0033] The spatial light modulator can be configured to modulate the characteristic of the first laser so that the wavefront aberration is equal to or less than a predetermined aberration.

[0034] The first laser corrected for the wavefront aberration in the spatial light modulator can be set as a standard light, and the spatial light modulator can be configured to modulate the characteristic of the first laser based on the standard light so that the wavefront aberration of the second optical system is increased or decreased.

[0035] The laser processing apparatus can further include a reflection member, and the third laser can be incident on the reflection member and the reflection member can reflect a fourth laser.

[0036] At least one of the reflection member or the second optical system can be moved so that the reflection member faces the second optical system.

[0037] The reflection member can include at least one of a flat mirror or a curved mirror. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1a A diagram for schematically showing a laser processing apparatus according to one embodiment.

[0039] Figure 1b A diagram for schematically showing a state in which a workpiece is processed using a laser according to one embodiment.

[0040] Figure 2a And Figure 2b A diagram for schematically showing a laser transmitted through a second optical system according to one embodiment and reflected by a reflection member.

[0041] Figure 3a is a front view of a stage and a reflecting member according to one embodiment.

[0042] Figure 3b is a schematic view showing a moving state of a second optical system according to one embodiment.

[0043] Figure 4 is a schematic view of a laser processing apparatus according to one embodiment.

[0044] Figure 5 is a schematic view of a laser processing apparatus according to one embodiment.

[0045] Figure 6 is a schematic view of a laser processing apparatus according to one embodiment.

[0046] Figure 7 is a schematic view of a laser processing apparatus according to one embodiment.

[0047] Figure 8 is a schematic view of a laser processing apparatus according to one embodiment.

[0048] Figure 9a and Figure 9b is a schematic view of a third optical system according to one embodiment.

[0049] Figure 10 is a schematic view of a laser processing apparatus according to one embodiment.

[0050] Figure 11 is a schematic view of a laser processing apparatus according to one embodiment.

[0051] Figure 12 is a schematic view of a laser processing apparatus according to one embodiment.

[0052] Figure 13 is a schematic view of a laser processing apparatus according to one embodiment.

[0053] Figure 14 is a schematic view of a laser processing apparatus according to one embodiment.

[0054]

REFERENCE NUMERALS

[0055] 1: laser processing apparatus

[0056] 10: laser source

[0057] 20: first optical system

[0058] 30: second optical system

[0059] 50: reflecting member

[0060] 100: wavefront measurement system

[0061] 101: Processor

[0062] 110: First wave of sensors

[0063] 120: Second wave front sensor

[0064] M: Workpiece to be processed Detailed Implementation

[0065] The advantages and features of the present invention, as well as the methods for achieving these advantages and features, will become clear with reference to the accompanying drawings and the detailed description of the embodiments. However, the present invention is not limited to the embodiments described below, but should be understood to be embodied in various different forms and include all modifications, equivalents, or substitutions included within the inventive spirit and scope. The embodiments described below are provided to make the disclosure of the invention complete and thorough, and to fully provide the scope of the invention to those skilled in the art. In describing the invention, detailed descriptions of relevant prior art will be omitted where it is determined that such descriptions may obscure the main points of the invention.

[0066] The terminology used in this application is for describing specific embodiments only and is not intended to limit the invention. Unless the context clearly indicates otherwise, the singular expressions also include the plural expressions. It should be understood that in this application, terms such as "comprising" or "having" are intended to specify the presence of features, numbers, steps, operations, constituent elements, components, or combinations thereof described in the specification, rather than precluding the possibility of the presence or addition of one or more other features or numbers, steps, operations, constituent elements, components, or combinations thereof. Terms such as "first" and "second" can be used to describe various constituent elements, but these constituent elements are not limited to these terms. The terms are used only to distinguish one constituent element from other constituent elements.

[0067] Hereinafter, embodiments according to the present disclosure will be described with reference to the accompanying drawings. When describing the embodiments with reference to the accompanying drawings, the same or corresponding constituent elements will be given the same reference numerals, and repeated descriptions of them will be omitted.

[0068] Figure 1a A diagram is provided to illustrate a laser processing apparatus as shown in the illustration. Figure 1b A schematic diagram illustrating the state of processing a workpiece using an illustrative laser, according to an example. Figure 2a and Figure 2b A schematic diagram illustrating laser light passing through a second optical system according to an embodiment and reflected by a reflecting component. Figure 3a This is a front view of an illustrative stage and reflective component. Figure 3b A schematic diagram illustrating the movement state of a second optical system according to an example.

[0069] ReferenceFigure 1a The laser processing apparatus 1 according to an embodiment can include a laser source 10, a first optical system 20, a second optical system 30, a stage 40, a reflecting member 50, and a wavefront measurement system 100 configured to sense a wavefront of a laser passing through the second optical system 30 and incident to a workpiece M to be processed.

[0070] The laser source 10 is configured to irradiate a laser to process along a processing preset line of the workpiece M to be processed. According to an embodiment, the workpiece M to be processed can include a wafer in the form of an ultra-thin film or a glass substrate in the form of an ultra-thin film as an object to be processed. For example, the workpiece M to be processed can be prepared in the form of a substrate including a transparent substance. However, the present disclosure is not limited thereto, and any other substrate capable of being processed using a laser can be used as the workpiece M to be processed.

[0071] The laser source 10 can include all laser irradiation apparatuses and is not limited to a specific embodiment. The laser irradiated by the laser source 10 can provide high-power energy to the workpiece M to be processed to perform a micro-processing process; a cutting process, such as a grooving process, a silicon inner dicing (SID) process; a drilling process; a surface treatment process, such as an annealing process, a laser left off process. In order to improve the processing accuracy of the workpiece M to be processed, it is important that the laser L incident to the workpiece M to be processed has a uniform beam quality.

[0072] As an example, the laser L irradiated by the laser source 10 can be more strongly emitted in a specific direction or have an asymmetric divergence pattern rather than being uniformly emitted in all directions. Therefore, a wavefront aberration can be generated due to the laser L irradiated by the laser source 10. Also, a defect or misalignment in the design or preparation of one or more optical systems 20, 30 can cause the wavefront aberration of the laser to be generated in the process in which the laser source 10 passes through one or more optical systems 20, 30.

[0073] In the case where the wavefront aberration is generated in the laser incident to the workpiece M to be processed, the laser can not form a complete focal point and become blurred or dispersed. This can cause a performance reduction in a laser processing process in which a focal point needs to be correctly formed. Also, an increase in the M2 value (a light quality index) of the laser can cause a reduction in light propagation characteristics, and thus, light can be dispersed in an undesired direction, causing a reduction in the overall optical efficiency of the laser processing apparatus 1.

[0074] The wavefront aberration of the laser light incident on the workpiece M to be processed can be generated by the laser source 10 itself or by one or more optical systems through which the laser light L irradiated by the laser source 10 passes, as described above, for example, by the first optical system 20 and the second optical system 30. The wavefront aberration generated by the laser source 10 can be confirmed during the manufacturing process. Also, the wavefront aberration generated by the first optical system 20 as a transmission optical system can be confirmed by measuring and comparing the wavefront information of the laser light incident on the first optical system 20 and the laser light emitted.

[0075] The wavefront aberration of the second optical system 30 as the processing optical system arranged opposite the workpiece M to be processed can be confirmed by measuring and comparing the wavefront information of the laser light incident on the second optical system 30 and the laser light emitted. Only, as Figure 1b indicated, the path of the light can change during the process in which the laser light L that has passed through the second optical system 30 as the processing optical system is incident on the workpiece M to be processed and the workpiece M to be processed is processed. Therefore, it can be difficult to directly measure the wavefront information of the laser light emitted toward the workpiece M to be processed.

[0076] According to one example, the reflecting member 50 can be arranged at a position at which the workpiece M to be processed is arranged and reflect the laser light L that has passed through the second optical system 30. As an example, as Figure 2a and Figure 2b indicated, the second laser light L2 can be incident on the second optical system 30. At this time, the reflecting member 50 can reflect the third laser light L3 that has passed through the second optical system 30 as the fourth laser light L4 and cause the fourth laser light L4 to be incident on the second optical system 30 again. At this time, the reflected fourth laser light L4 can move through a path substantially identical to the paths of the third laser light L3 and the second laser light L2.

[0077] As an example, the reflecting member 50 can be an arbitrary reflecting unit capable of causing the reflected fourth laser light L4 to move through a path substantially identical to the paths of the third laser light L3 and the second laser light L2. For example, the reflecting member 50 can be a plane mirror as Figure 2a indicated. In the case in which the reflecting member 50 is a plane mirror, the reflecting member 50 can be provided to have a relatively small thickness.

[0078] Also, for example, the reflecting member 50 can be a curved mirror as Figure 2b indicated. In the case in which the reflecting member 50 is a curved mirror, by causing the focal point of the second optical system 30 to coincide with the center of curvature of the reflecting member 50, the incident path of the third laser light L3 and the emission path of the fourth laser light L4 can be caused to coincide regardless of the tilt of the second optical system 30.

[0079] In a case where the third laser L3 transmitted through the second optical system 30 is reflected by the reflection member 50 as the fourth laser L4 and transmitted through the same path through the second optical system 30, a double path process, which is a process of transmitting twice through the second optical system 30, can be performed. At this time, the wavefront aberration generated by the second optical system 30 can be quantitatively measured as 2 times. Thus, the wavefront aberration generated by the second optical system 30 can be independently measured regardless of the kind of the workpiece M and the processing type.

[0080] As described above, by using the reflection member 50 instead of the workpiece M, only the wavefront aberration generated by the second optical system 30 can be independently measured. In a case where the reflection member 50 is arranged to be opposite to the second optical system 30 to measure the wavefront aberration generated by the second optical system 30, positional interference can occur between the reflection member 50 and the workpiece M.

[0081] Referring to Figure 3a and Figure 3b , in order to prevent the positional interference between the reflection member 30 and the workpiece M, the reflection member 50 can be arranged to be spaced apart from each other at a certain interval with the stage 40 supporting the workpiece M. As an example, the reflection member support 51 can be arranged at a position close to the stage 40 supporting the workpiece M. At this time, the reflection member 50 can be supported by the reflection member support 51. As an example, in a case where the wavefront aberration generated by the second optical system 30 is measured, the second optical system 30 can be moved to be opposite to the reflection member 50 as shown in Figure 3b . Also, in a case where the laser processing apparatus 1 processes the workpiece M, the second optical system 30 can be moved to be opposite to the workpiece M as shown in Figure 3b .

[0082] In the above-described example, it is described that the second optical system 30 is moved according to the processing of the workpiece M or the measurement of the wavefront aberration generated by the second optical system 30, but the present disclosure is not limited thereto. As an example, if the position of the second optical system 30 is fixed, the stage 40 supporting the workpiece M can be moved to be opposite to the second optical system 30 in the process of processing the workpiece M. Also, in the process of measuring the wavefront aberration generated by the second optical system 30, the reflection member support 51 supporting the reflection member 50 can be moved to be opposite to the second optical system 30. Also, in a case where the positions of the second optical system 30 and the stage 40 are fixed, it is obvious that the reflection member 50 or the workpiece M can be alternately arranged on the stage 40 in the process of measuring the wavefront aberration generated by the second optical system 30 or processing the workpiece M.

[0083] Hereinafter, a process of measuring only wavefront aberration generated due to the second optical system 30 independently using the wavefront measurement system 100 is described in more detail.

[0084] Figure 4 FIG. 1 is a schematic diagram of a laser processing apparatus according to an example.

[0085] Referring to Figure 4 , the wavefront measurement system 100 according to an example can include a first wavefront sensor 110 configured to measure first wavefront information of a second laser L2, a second wavefront sensor 120 configured to measure second wavefront information of a fourth laser L4, a first optical component 131 configured to cause the second laser L2 to be incident on the first wavefront sensor 110, and a second optical component 132 configured to cause the fourth laser L4 to be incident on the second wavefront sensor 120. For example, the first optical component 131 can be a polarizing beam splitter or a coated mirror configured to split the second laser L2 into a 2-1 laser L 21 incident on the first wavefront sensor 110 and a 2-2 laser L 22 incident on the second optical system 30. According to an example, the processor 101 can calculate wavefront aberration from the first wavefront information and the second wavefront information received from the first wavefront sensor 110 and the second wavefront sensor 120. Hereinafter, a method of measuring wavefront aberration generated due to the second optical system 30 during a process along a movement path of the first laser L1 emitted from the laser source 10 is described in more detail.

[0086] The laser source 10 emits the first laser L1. According to an example, wavefront aberration information generated due to the laser source 10 itself can be calculated in advance and transmitted to the processor 101.

[0087] The first laser L1 can be incident on the first optical system 20 and transmitted through the first optical system 20 as the second laser L2. According to an example, wavefront aberration information generated due to the first optical system 20 can be calculated in advance and transmitted to the processor 101.

[0088] As an example, the first optical system 20 can be a transmission optical system. For example, when the first optical system 20 is a transmission optical system, the first optical system 20 can effectively and without loss transmit the first laser L1 emitted from the laser source 10 to the second optical system. As an example, the first optical system 20 can be an optical system, for example, a 4F system, including one or more optical components configured to adjust a light path, such as one or more lenses, one or more mirrors, or one or more prisms.

[0089] However, the present disclosure is not limited thereto, and the first optical system 20 can also include any kind of transfer system capable of changing the characteristics of the first laser L1, such as expanding or reducing the first laser L1, or changing the shape of the first laser L1, in the process of transferring the first laser L1 to the second optical system 30.

[0090] The first laser L1 incident on the first optical system 20 can be transmitted through the first optical system 20 and emitted as a second laser L2. The second laser L2 can be incident on a wavefront measurement system 100 configured to measure wavefront information.

[0091] As one example, the second laser L2 can be incident on a first optical component 131 included in the wavefront measurement system 100, such as a polarizing beam splitter. The second laser L2 incident on the first optical component 131 can be split into a 2-1 laser L 21 and a 2-2 laser L 22 At this time, the 2-1 laser L 21 may be incident on a first wavefront sensor 110. Also, the 2-2 laser L 22 may be transmitted through a second optical component 132 to be described later, and incident on the second optical system 30.

[0092] The first wavefront sensor 110 can measure the form of the wavefront by measuring the phase information of the 2-1 laser L 21 incident thereon. According to one example, the first wavefront sensor 110 can measure the phase information of the 2-1 laser L 21 incident thereon in real time to monitor the wavefront form in real time. As one example, the first wavefront sensor 110 can measure the local tilt of the wavefront due to aberration and integrate information about the tilt to reconstruct the entire wavefront form.

[0093] The wavefront aberration of the laser can be calculated by comparing the standard wavefront information of the laser as a standard and the measurement wavefront information of the laser to be measured. Therefore, in order to confirm the wavefront aberration generated by the second optical system 30, if the 2-2 laser L 22 incident on the second optical system 30 is a reference wavefront of the laser as a standard, the fourth laser L4 reflected by the reflecting member 50 and returned after being transmitted through the second optical system 30 can be a measurement wavefront of the laser to be measured.

[0094] When the wavefront aberration is calculated, in a case where a measurement position of a reference wavefront of a laser light as a standard and a measurement position of a measurement wavefront of a laser light to be measured are different, an error due to the measurement position can be added. In this case, an error value due to the measurement position can be added to a calculated wavefront aberration value, and thus a wavefront aberration due to the second optical system 30 itself cannot be correctly confirmed.

[0095] According to one example, the wavefront measurement system 100 can set a standard wavefront measurement position V of a laser light as a standard and a measurement wavefront measurement position V of a laser light to be measured to be the same. At this time, the measurement position V of the standard wavefront can be disposed at an emission hole of the first optical system 20 and an incidence hole of the second optical system 30. As an example, a position at which first wavefront information of the second laser light L2 incident on the second optical system 30 is measured and a position at which fourth wavefront information of the fourth laser light L4 reflected by the reflection member 50 after passing through the second optical system 30 is measured can be set to be the same. Hereinafter, the standard wavefront measurement position V of a laser light as a standard and the measurement wavefront measurement position V of a laser light to be measured are defined as a wavefront measurement position V.

[0096] The first wavefront sensor 110 can be configured to measure phase information of a standard wavefront of a laser light as a standard, i.e., the 2-2 laser light L 22 at the wavefront measurement position V. In a case where the first wavefront sensor 110 is directly disposed at the wavefront measurement position V to measure phase information of the 2-2 laser light L 22 , positional interference can occur.

[0097] According to one example, the first wavefront sensor 110 can be disposed to face a direction different from a direction of the wavefront measurement position V with reference to the first optical member 131. At this time, a 1-1 distance d 11 between the first wavefront sensor 110 and the first optical member 131 and a 1-2 distance d 12 between the first optical member 131 and the wavefront measurement position V can be the same. As an example, the first wavefront sensor 110 can be disposed to be spaced apart from the first optical member 131 by the 1-1 distance d 11 in a first direction X. At this time, the wavefront measurement position V can be disposed to be spaced apart from the first optical member 131 by the 1-2 distance d 12 in a second direction Z. At this time, the 1-1 distance d 11 and the 1-2 distance d 12 may be set to be the same.

[0098] The 1-1 distance d 11 and the 1-2 distance d 12The first wavefront information of the 2-1 laser L 21 measured by the first wavefront sensor 110 can be substantially the same as the first wavefront information of the 2-2 laser L 22 Therefore, the first wavefront sensor 110 can measure the first wavefront information of the 2-1 laser L 21 split from the second laser L2 by the first optical member 131 to confirm the first wavefront information of the 2-2 laser L 22

[0099] The 2-2 laser L 22 can pass through the wavefront measurement position V and the second optical member 132. At this time, the wavefront measurement position V can be disposed between the first optical member 131 and the second optical member 132. The 2-2 laser L 22 passing through the second optical member 132 can be incident on the second optical system 30. The 2-2 laser L 22 incident on the second optical system 30 can be emitted as a third laser L3. As shown in FIGS. Figure 2a and Figure 2b , the third laser L3 passing through the second optical system 30 can be reflected by the reflecting member 50 as a fourth laser L4. The fourth laser L4 can pass through the second optical system 30 again and be incident on the second wavefront sensor 120 by the second optical member 132.

[0100] The second wavefront sensor 120 can measure the phase information of the fourth laser L4, which is a standard wavefront of a laser serving as a standard, at the wavefront measurement position V. According to one example, the second wavefront sensor 120 can measure the phase information of the fourth laser L4 as needed when the second wavefront sensor 120 operates wavefront aberration, for example, using the reflecting member 50 to emit the fourth laser L4. In the case where the second wavefront sensor 120 is directly disposed at the wavefront measurement position V to measure the phase information of the fourth laser L4, positional interference can occur.

[0101] According to one example, the second wavefront sensor 120 can be disposed to face a direction different from that of the wavefront measurement position V with the second optical member 132 as a reference. At this time, a 2-1 distance d 21 between the second wavefront sensor 120 and the second optical member 132 and a 2-2 distance d 22 between the second optical member 132 and the wavefront measurement position V can be the same. As an example, the second wavefront sensor 120 can be disposed to be spaced apart from the second optical member 132 by a 2-1 distance d 21 along a first direction X. At this time, the wavefront measurement position V can be disposed to be spaced apart from the second optical member 132 by a 2-2 distance d 22 ​are spaced apart. At this time, the 2-1 distance d 21 is set to be the same as the 2-2 distance d 22 may be set to be the same.

[0102] Since the first distance d 21 is set to be the same as the 2-2 distance d 22 set to be the same, the second wavefront information of the fourth laser L4 measured by the second wavefront sensor 120 can be substantially the same as the second wavefront information of the fourth laser L4 that can be measured at the wavefront measurement position V. Accordingly, the second wavefront sensor 120 can confirm the second wavefront information of the fourth laser L4 that can be measured at the wavefront measurement position V.

[0103] The first wavefront information and the second wavefront information measured by the first wavefront sensor 110 and the second wavefront sensor 120, respectively, can be transmitted to the processor 101. The processor 101 can be configured to calculate wavefront aberration of the second optical system 30 using the first wavefront information and the second wavefront information. According to one example, the processor 101 can be configured to calculate wavefront aberration of the second optical system 30 using Zernike polynomials. For example, the first wavefront information and the second wavefront information measured by the first wavefront sensor 110 and the second wavefront sensor 120, respectively, can be analyzed by Zernike polynomials. Various forms of wavefront aberration, defocus, astigmatism, coma, etc. can be mathematically expressed by Zernike polynomials, based on which the magnitude and the kind of wavefront aberration can be quantitatively calculated. As described above, in the wavefront measurement system 100 according to one example, the measurement position V of the standard wavefront of the laser serving as a standard and the measurement wavefront measurement position V of the laser to be measured are set to be the same, so that wavefront aberration generated due to the second optical system 30 can be more accurately measured. That is, since an error that can occur due to the measurement position when the measurement position V of the standard wavefront of the laser serving as a standard and the measurement wavefront measurement position V of the laser to be measured are different does not occur, wavefront aberration due to the second optical system 30 itself can be correctly confirmed.

[0104] Figure 5 is a schematic view of a laser processing apparatus according to an embodiment.

[0105] Referring to Figure 5 , the wavefront measurement system 100 according to one example can include a first wavefront sensor 110, a second wavefront sensor 120, a first optical member 131, a second optical member 132, and a quarter-waveplate (QWP) 140. Other components except for the first optical member 131, the second optical member 132, and the quarter-waveplate 140 are the same as those described with reference to Figure 4The configurations are substantially the same, and thus will not be described again here.

[0106] According to one example, each of the first optical member 131 and the second optical member 132 can include a polarizing beam splitter (PBS). In the case where each of the first optical member 131 and the second optical member 132 includes a polarizing beam splitter, the laser light can be separated or combined according to the polarization state of the incident laser light.

[0107] As an example, the first optical member 131 and the second optical member 132 can operate in a manner that reflects a specific polarization, such as S-polarization, and transmits the other orthogonal polarization, such as P-polarization. For example, the first optical member 131 can separate the second-1 laser light L 21 toward the first wavefront sensor 110. Thereby, the first wavefront sensor 110 can obtain first wavefront information of the second-1 laser light L 21 .

[0108] Also, the second-2 laser light L 22 , which is P-polarization, can be transmitted so that the second-2 laser light L 22 is directed toward the second optical member 132. The second-2 laser light L 22 , which is P-polarization, can be transmitted through the second optical member 132 and incident on the second optical system 30. The third laser light L3, which is transmitted through the second optical system 30, can be reflected by the reflecting member 50 as fourth laser light L4.

[0109] The quarter wave plate 140 according to one example can be configured to change the polarization of the fourth laser light L4. As an example, the polarization of the third laser light L3, which has been transmitted through the second optical member 132, can be changed from P-polarization to circular polarization during transmission through the quarter wave plate 140. Also, the fourth laser light L4, which is reflected by the reflecting member 50, can be changed from circular polarization to S-polarization during transmission through the quarter wave plate 140.

[0110] In the case where the polarization of the fourth laser light L4, which has been transmitted through the quarter wave plate 140, is changed to S-polarization, the fourth laser light L4, which is incident on the second optical member 132, can be reflected toward the second wavefront sensor 120. Thereby, the second wavefront sensor 120 can obtain second wavefront information of the fourth laser light L4. The first wavefront information and the second wavefront information, which are obtained by the first wavefront sensor 110 and the second wavefront sensor 120, respectively, can be transmitted to the processor 101. The process of operating wavefront aberration using the first wavefront information and the second wavefront information is the same as that described with reference to FIG. 2, and thus will not be described again here. Figure 4The configurations are substantially the same as described above, and thus, will not be described again here.

[0111] Figure 6 A schematic diagram of a laser processing apparatus according to an embodiment.

[0112] Referring to Figure 6 , the wavefront measurement system 100 according to an example can include a first wavefront sensor 110, a second wavefront sensor 120, and an optical component 130. Except that the first optical component 131 and the second optical component 132 are replaced by one optical component 130, the other configurations are substantially the same as described with reference to Figure 4 The configurations are substantially the same as described above, and thus, will not be described again here.

[0113] According to an example, the second laser L2 can be incident on the optical component 130 included in the wavefront measurement system 100, such as a polarizing beam splitter. The second laser L2 incident on the optical component 130 can be split into a 2-1 laser L 21 and a 2-2 laser L 22 At this time, the 2-1 laser L 21 may be incident on the first wavefront sensor 110. Also, the 2-2 laser L 22 may be incident on the second optical system 30.

[0114] The first wavefront sensor 110 can be configured to measure the phase information of the incident 2-1 laser L 21 to measure the form of the wavefront. According to an example, with the optical component 130 as a reference, the first wavefront sensor 110 can be disposed to face a direction different from the direction of the wavefront measurement position V. At this time, a 1-1 distance d 11 between the first wavefront sensor 110 and the optical component 130 and a 1-2 distance d 12 between the optical component 130 and the wavefront measurement position V can be the same. As an example, the first wavefront sensor 110 can be disposed to be spaced apart from the optical component 130 by the 1-1 distance d 11 in a first direction X. At this time, the wavefront measurement position V can be disposed to be spaced apart from the optical component 130 by the 1-2 distance d 12 in a second direction Z. At this time, the 1-1 distance d 11 and the 1-2 distance d 12 may be set to be the same.

[0115] Since the 1-1 distance d 11 and the 1-2 distance d 12 are set to be the same, the first wavefront information of the 2-1 laser L 21 measured by the first wavefront sensor 110 and the 2-2 laser L 22The first wavefront information of the first laser Ll can be substantially the same. Thus, the first wavefront sensor 110 can measure the first wavefront information of the first laser Ll split off from the second laser L2 by the optical component 130. 21 The first wavefront information of the first laser Ll can be substantially the same. Thus, the first wavefront sensor 110 can measure the first wavefront information of the first laser Ll split off from the second laser L2 by the optical component 130. 22 The first wavefront information of the first laser Ll can be substantially the same. Thus, the first wavefront sensor 110 can measure the first wavefront information of the first laser Ll split off from the second laser L2 by the optical component 130.

[0116] The first wavefront information of the first laser Ll can be substantially the same. Thus, the first wavefront sensor 110 can measure the first wavefront information of the first laser Ll split off from the second laser L2 by the optical component 130. 22 The second laser L2 can be transmitted through the wavefront measurement position V to the second optical system 30. At this time, the wavefront measurement position V can be disposed between the optical component 130 and the second optical system 30. The second laser L2 incident on the second optical system can be split off by the optical component 130. 22 The first wavefront information of the first laser Ll can be substantially the same. Thus, the first wavefront sensor 110 can measure the first wavefront information of the first laser Ll split off from the second laser L2 by the optical component 130. Figure 2a and Figure 2b The third laser L3 transmitted through the second optical system 30 can be reflected by the reflecting component 50 to the fourth laser L4 as shown in FIGS. 10 and 11. The fourth laser L4 can be transmitted through the second optical system 30 again and incident on the second wavefront sensor 120 by the optical component 130.

[0117] The second wavefront sensor 120 can measure the phase information of the fourth laser L4, which is a standard wavefront of a laser as a standard, at the wavefront measurement position V. According to one example, the second wavefront sensor 120 can be disposed to face a direction different from that of the wavefront measurement position V with the optical component 130 as a reference. The second wavefront sensor 120 according to one example can be disposed to be spaced apart from the wavefront measurement position V by a third distance d3.

[0118] Since the second wavefront sensor 120 is disposed to be spaced apart from the wavefront measurement position V by the third distance d3, wavefront aberration that occurs as the fourth laser L4 moves the third distance d3 can additionally occur. Thus, the second wavefront sensor 120 can measure second wavefront information including additional wavefront aberration due to the second wavefront sensor 120 being spaced apart from the wavefront measurement position V by the third distance d3.

[0119] The first wavefront information and the second wavefront information measured by the first wavefront sensor 110 and the second wavefront sensor 120, respectively, can be transmitted to the processor 101. The processor 101 can be configured to calculate the wavefront aberration of the second optical system 30 using the first wavefront information and the second wavefront information. At this time, the second wavefront information measured by the second wavefront sensor 120 can include an additional wavefront aberration occurring due to the second wavefront sensor 120 being spaced apart from the wavefront measurement position V by the third distance d3, and thus the processor 101 can correct the second wavefront information based on the third distance d3 based on beam propagation methods (BPM). The processor 101 can calculate the wavefront aberration of the second optical system 30 using the first wavefront information and the corrected second wavefront information. The process of calculating the wavefront aberration based on the first wavefront information and the corrected second wavefront information will be described with reference to FIG. 4, and thus a detailed description thereof will not be provided herein. Figure 4

[0120] Referring to FIG. 4, Figure 4 to Figure 6 Figure 6 , the optical member 130 can be formed as a single configuration, the entire optical system can be more simply designed, and the laser processing apparatus 1 can be miniaturized. However, referring to Figure 6 , the second wavefront information based on the third distance d3 is corrected based on beam propagation methods, and unless an additional correction process is performed as described above, the wavefront aberration can be more accurately confirmed. Figure 4

[0121] Figure 7 is a schematic view of a laser processing apparatus according to an embodiment.

[0122] Referring to FIG. 4, Figure 7 According to one embodiment, the wavefront measurement system 100 can include a first wavefront sensor 110, a second wavefront sensor 120, an optical member 130, and a quarter wave plate 140 disposed between the optical member 130 and the second optical system 30. The other configurations of the optical member 130 and the quarter wave plate 140 are substantially the same as those described with reference to Figure 6

[0123] According to one embodiment, the optical member 130 can include a polarization beam splitter. In the case where the optical member 130 includes the polarization beam splitter, the laser can be separated or combined according to the polarization state of the incident laser.

[0124] ​​​​As an example, the optical member 130 can operate in a manner of reflecting a specific polarization, such as S-polarization, and transmitting the other orthogonal polarization, such as P-polarization. For example, the optical member 130 can reflect the 2-1 laser L2-1, which is S-polarized, as a second laser L2 toward the first wavefront sensor 110 in the second laser L2 transmitted through the optical member 130. 21 Thus, the first wavefront sensor 110 can obtain first wavefront information of the 2-1 laser L 21 .

[0125] Also, the 2-2 laser L 22 , which is P-polarized, can be incident to the quarter wave plate 140. According to one example, the quarter wave plate 140 can be configured to change the polarization of the 2-2 laser L 22 . As an example, the polarization of the 2-2 laser L 22 may be changed from P-polarization to circular polarization in the process of transmitting the 2-2 laser L 22 through the quarter wave plate 140. The 2-2 laser L 22 changed to circular polarization can be incident to the second optical system 30. The third laser L3, which has transmitted through the second optical system 30, can be reflected by the reflecting member 50 as a fourth laser L4. According to one example, the quarter wave plate 140 can change the polarization of the fourth laser L4. As an example, the fourth laser L4 reflected by the reflecting member 50 can be changed from circular polarization to S-polarization in the process of transmitting the fourth laser L4 through the quarter wave plate 140 again.

[0126] In the case where the polarization of the fourth laser L4 transmitted through the quarter wave plate 140 is changed to S-polarization, the fourth laser L4 incident to the optical member 130 can be reflected toward the second wavefront sensor 120. Thus, the second wavefront sensor 120 can obtain second wavefront information of the fourth laser L4. The process of calculating wavefront aberration using the first wavefront information and the second wavefront information is substantially the same as described with reference to Figure 6 , and thus, will not be described again here.

[0127] Figure 8 FIG. 1 is a schematic view of a laser processing apparatus according to an embodiment. Figure 9a and Figure 9b FIG. 2 is a schematic view of a third optical system according to an embodiment.

[0128] Referring to Figure 8 , according to one example, a wavefront measurement system 100 can include a first wavefront sensor 110, a second wavefront sensor 120, an optical member 130, and a third optical system 150. Except that the third optical system 150 is additionally disposed between the optical member 130 and the second wavefront sensor 120, the other configurations are substantially the same as described with reference to Figure 6The configurations are substantially the same, and thus, will not be described again here.

[0129] According to one example, the second laser L2 can be incident on an optical component 130 included in the wavefront measurement system 100, such as a polarizing beam splitter. The second laser L2 incident on the optical component 130 can be split into a 2-1 laser L 21 and a 2-2 laser L 22 At this time, the 2-1 laser L 21 may be incident on the first wavefront sensor 110. Also, the 2-2 laser L 22 may be incident on the second optical system 30.

[0130] The first wavefront sensor 110 measures the form of the wavefront by measuring the phase information of the 2-1 laser L 21 incident thereon. According to one example, the first wavefront sensor 110 can be disposed to face a direction different from the direction of the wavefront measurement position V, with the optical component 130 as a reference. At this time, a 1-1 distance d 11 between the first wavefront sensor 110 and the optical component 130 and a 1-2 distance d 12 between the optical component 130 and the wavefront measurement position V can be the same. As an example, the first wavefront sensor 110 can be disposed to be spaced apart from the optical component 130 by the 1-1 distance d 11 in a first direction X. At this time, the wavefront measurement position V can be disposed to be spaced apart from the optical component 130 by the 1-2 distance d 12 in a second direction Z. At this time, the 1-1 distance d 11 and the 1-2 distance d 12 may be set to be the same.

[0131] Since the 1-1 distance d 11 and the 1-2 distance d 12 are set to be the same, the first wavefront information of the 2-1 laser L 21 measured by the first wavefront sensor 110 and the first wavefront information of the 2-2 laser L 22 may be substantially the same. Thus, the first wavefront sensor 110 can measure the first wavefront information of the 2-1 laser L 21 split from the second laser L2 by the optical component 130 to confirm the first wavefront information of the 2-2 laser L 22 .

[0132] The 2-2 laser L 22 may be incident on the second optical system 30 through the wavefront measurement position V. At this time, the wavefront measurement position V can be disposed between the optical component 130 and the second optical system 30. The 2-2 laser L22 The third laser light L3 that has passed through the second optical system 30 can be reflected by the reflection member 50 as fourth laser light L4. The fourth laser light L4 can pass through the second optical system 30 again and pass through the optical member 130 to be incident on the third optical system 150. The fourth laser light L4 that is incident on the third optical system 150 can pass through the third optical system 150 to be emitted as fifth laser light L5 and be incident on the second wavefront sensor 120. As an example, if the third optical system 150 is not disposed between the optical member 130 and the second wavefront sensor 120, an error occurs due to the wavefront measurement position V, and thus it is not possible to correctly confirm the wavefront aberration due to the second optical system 30 itself.

[0133] According to one example, the third optical system 150 can be a transfer optical system configured to transfer laser light such that the fifth laser light L5 that passes through the third optical system 150 is substantially the same as the fourth laser light L4 at the wavefront measurement position V. As an example, in the case where the fourth laser light L4 that passes through the wavefront measurement position V passes through the third optical system 150 as a transfer optical system and is incident on the second wavefront sensor 120, the third wavefront information of the fifth laser light L5 that is incident on the second wavefront sensor 120 can be substantially the same as the second wavefront information of the fourth laser light L4 at the wavefront measurement position V. According to one example, the third optical system 150 is additionally disposed between the optical member 130 and the second wavefront sensor 120, and thus it is possible to transfer wavefront information that is substantially the same as the second wavefront information of the fourth laser light L4 at the wavefront measurement position V to the second wavefront sensor 120 even in the case where a single optical member 130 is used.

[0134] As shown in FIG. 9, in the case where the third optical system 150 according to one example includes a 4F system, the third optical system 150 can use a Fourier Optics concept. As an example, the third optical system 150 can include a 3-1 optical lens 151 and a 3-2 optical lens 152 and can be disposed to have a total system length of 4f based on a focal length f between the 3-1 optical lens 151 and the 3-2 optical lens 152 and a focal length f between the 3-1 optical lens 151 and the 3-2 optical lens 152. However, the present disclosure is not limited thereto, and it is obvious that the third optical system 150 can include any transfer optical system configured to make the third wavefront information of the fifth laser light L5 that is incident on the second wavefront sensor 120 and the second wavefront information of the fourth laser light L4 at the wavefront measurement position V substantially the same, for example, a 4F system in which a doublet relationship exists between the focal lengths f as shown in FIG. 10. Figure 9b

[0135] ​As described above, in a case where the third wavefront information of the fifth laser L5 measured by the second wavefront sensor 120 is substantially the same as the second wavefront information of the fourth laser L4 at the wavefront measurement position V, the first wavefront information measured using the first wavefront sensor 110 and the second wavefront information measured using the second wavefront sensor 120 can have substantially the same wavefront measurement position V. According to one example, the wavefront measurement position V can be arranged between the optical member 130 and the second optical system 30.

[0136] The first wavefront information and the second wavefront information measured by the first wavefront sensor 110 and the second wavefront sensor 120, respectively, can be transmitted to the processor 101. The processor 101 can calculate the wavefront aberration of the second optical system 30 using the first wavefront information and the second wavefront information. The process of calculating the wavefront aberration based on the first wavefront information and the second wavefront information is substantially the same as that described with reference to Figure 4 The description is substantially the same as that described with reference to

[0137] According to one example, since the third optical system 150 is attached between the optical member 130 and the second wavefront sensor 120, a single optical member 130 can be used to ensure design convenience. Also, since the first wavefront sensor 110 and the second wavefront sensor are arranged at positions corresponding to each other with reference to the optical member 130, miniaturization of the entire system can be achieved. Also, since a method of numerically correcting the second wavefront information based on a beam propagation method is not used, the wavefront aberration can be more accurately confirmed.

[0138] Figure 10 A schematic diagram of a laser processing apparatus according to an embodiment.

[0139] Reference Figure 10 According to one example, the wavefront measurement system 100 can include the first wavefront sensor 110, the second wavefront sensor 120, the optical member 130, and the quarter wave plate 140 arranged between the optical member 130 and the second optical system 30. The other configurations except for the optical member 130 and the quarter wave plate 140 are substantially the same as those described with reference to Figure 8 The description is substantially the same as that described with reference to

[0140] According to one example, the optical member 130 can include a polarization beam splitter. In a case where the optical member 130 includes the polarization beam splitter, the laser can be separated or combined according to the polarization state of the incident laser.

[0141] As an example, optical component 130 can operate in a manner that reflects specific polarized light, such as S-polarized light, while allowing other orthogonally polarized light, such as P-polarized light, to pass through. For instance, optical component 130 can transmit the second laser L2, which is S-polarized, as a second laser L2 that passes through optical component 130. 21 The light is reflected towards the first wavefront sensor 110. Thus, the first wavefront sensor 110 can obtain the second-first laser L... 21 The first wave of pre-war information.

[0142] Furthermore, as the second-second laser L of P-polarized light... 22 It can be incident on a quarter-wave plate 140. According to an example of a quarter-wave plate 140, the second-second laser L can be changed. 22 The polarized light. As an example, in the second-2nd laser L that has passed through optical component 130. 22 During the process of passing through a quarter-wave plate 140, the second-second laser L 22 The polarized light can be changed from P-polarized light to circularly polarized light. The second laser L-2 is changed to circularly polarized light. 22 The light can be incident on the second optical system 30. The third laser L3, which has passed through the second optical system 30, can be reflected by the reflecting component 50 as a fourth laser L4. According to an example, the polarization of the fourth laser L4 can be changed by the quarter-wave plate 140. As an example, the fourth laser L4 reflected by the reflecting component 50 can be changed from circularly polarized to S-polarized as it passes through the quarter-wave plate 140 again.

[0143] When the polarized light of the fourth laser L4, which has passed through the quarter-wave plate 140, is changed to S-polarized light, the fourth laser L4 incident on the optical component 130 can be reflected and incident on the third optical system 150. The fourth laser L4 can pass through the third optical system 150 and be emitted as the fifth laser L5, which then enters the second wavefront sensor 120. Thus, the second wavefront sensor 120 can obtain the third wavefront information of the fifth laser L5. As described above, the third wavefront information of the fifth laser L5 and the second wavefront information of the fourth laser L4 can be substantially the same. The process of calculating wavefront aberrations using the first and second wavefront information is referenced. Figure 6 The content described is essentially the same, so it will not be repeated here.

[0144] Figure 11 This is a schematic diagram of a laser processing apparatus according to one embodiment.

[0145] Reference Figure 11According to one example, the wavefront measurement system 100 can include a first wavefront sensor 110, a second wavefront sensor 120, an optical member 130, a third optical system 150, and a polarization beam splitter 160. Except that the polarization beam splitter 160 is further disposed between the first optical system 20 and the first wavefront sensor 110 and the first laser light L1 emitted from the laser light source 10 has a certain polarization, the other configurations are substantially the same as those described with reference to FIG. 1, and thus, will not be described again here. Figure 10 The configurations described are substantially the same, and thus, will not be described again here.

[0146] According to one example, the first laser light L1 emitted from the laser light source 10 can have a certain polarization, for example, P-polarization. Except for the case where the laser light is directly emitted from the laser light source 10, an optical member can be disposed for the laser light emitted from the laser light source 10 to adjust the first laser light L1 to have a certain polarization.

[0147] The first laser light L1 having a certain polarization can pass through the first optical system 20 as a transmission optical system and be emitted as second laser light L2. The second laser light L2 can be incident on the polarization beam splitter 160 included in the wavefront measurement system 100. The second laser light L2 incident on the polarization beam splitter 160 can be split into a 2-1 laser light L 21 and a 2-2 laser light L 22 At this time, the 2-1 laser light L 21 may be incident on the first wavefront sensor 110. Also, the 2-2 laser light L 22 may be incident on the optical member 130. According to one example, the energy ratio of the 2-1 laser light L 21 and the 2-2 laser light L 22 may be 1:99. In order to obtain first wavefront information, the ratio of the energy incident on the first wavefront sensor 110 can be minimized to improve the processing efficiency. However, the present disclosure is not limited thereto, and the energy ratio of the 2-1 laser light L 21 and the 2-2 laser light L 22 may be differently determined.

[0148] The first wavefront sensor 110 can measure the phase information of the incident 2-1 laser light L 21 to measure first wavefront information. Since the distance between the first wavefront sensor 110 and the polarization beam splitter 160 and the distance between the polarization beam splitter 160 and the wavefront measurement position V are set to be the same, the first wavefront information of the 2-1 laser light L 21 measured by the first wavefront sensor 110 and the first wavefront information of the 2-2 laser light L 22 may be substantially the same. Thus, the first wavefront sensor 110 can measure the 2-1 laser light L 21The first wave of information was used to confirm the 2-2 laser L 22 The first wave of pre-war information.

[0149] Laser L, No. 2-2 22 The light can sequentially pass through the optical component 130, the wavefront measurement position V, and the quarter-wave plate 140 before entering the second optical system 30. In this case, the optical component 130 can be a polarizing beam splitter, allowing only laser light with a certain polarization to pass through. As an example, the optical component 130 can be a polarizing beam splitter configured to allow only the second-second laser L... 22 The polarized light has the same polarization characteristics as p-polarized light. Therefore, the second-third laser L emitted through optical component 130... 23 It can have P-polarized light.

[0150] As the 2nd-3rd laser L of P-polarization 23 It can be incident on a quarter-wave plate 140. According to an example of a quarter-wave plate 140, the second and third lasers L can be altered. 23 The polarized light. As an example, in the second-to-third laser L that has already passed through optical component 130... 23 During the process of passing through a quarter-wave plate 140, the 2nd and 3rd lasers L 23 The polarized light can be changed from P-polarized light to circularly polarized light. The third laser L3, converted to circularly polarized light, can be incident on the second optical system 30. The second and third lasers L... 23 The light emitted through the second optical system 30 can be emitted as a third laser L3. The third laser L3 emitted through the second optical system 30 can be reflected by the reflecting component 50 as a fourth laser L4. According to one example, the quarter-wave plate 140 can change the polarization of the fourth laser L4. As an example, the fourth laser L4 reflected by the reflecting component 50 can be changed from circularly polarized to S-polarized as it passes through the quarter-wave plate 140 again.

[0151] The fourth laser L4, converted to S-polarization, can be reflected by optical component 130 and incident on the third optical system 150. The fourth laser L4 incident on the third optical system 150 can pass through the third optical system 150 and be emitted as the fifth laser L5, which is then incident on the second wavefront sensor 120.

[0152] According to one embodiment, the third optical system 150 can be a transmission optical system configured to transmit the laser light such that the fifth laser light L5 passing through the third optical system 150 is substantially the same as the fourth laser light L4 at the wavefront measurement position V. As an example, in a case where the fourth laser light L4 passing through the wavefront measurement position V is transmitted through the third optical system 150 as a transmission optical system and is incident on the second wavefront sensor 120, the third wavefront information of the fifth laser light L5 incident on the second wavefront sensor 120 can be substantially the same as the second wavefront information of the fourth laser light L4 at the wavefront measurement position V.

[0153] In a case where the third wavefront information of the fifth laser light L5 measured by the second wavefront sensor 120 is substantially the same as the second wavefront information of the fourth laser light L4 at the wavefront measurement position V, the first wavefront information measured using the first wavefront sensor 110 and the second wavefront information measured using the second wavefront sensor 120 can have a substantially same wavefront measurement position V. According to one embodiment, the wavefront measurement position V can be arranged between the optical component 130 and the second optical system 30.

[0154] The first wavefront information and the second wavefront information measured by the first wavefront sensor 110 and the second wavefront sensor 120, respectively, can be transmitted to the processor 101. The processor 101 can use the first wavefront information and the second wavefront information to calculate a wavefront aberration of the second optical system 30. The process of calculating the wavefront aberration based on the first wavefront information and the second wavefront information is substantially the same as that described with reference to Figure 4 the contents described above, and thus, will not be described herein.

[0155] Figure 12 A schematic diagram of a laser processing apparatus according to an embodiment.

[0156] Referring to Figure 12 , according to one embodiment, the wavefront measurement system 100 can include a first wavefront sensor 110, a second wavefront sensor 120, an optical component 130, a third optical system 150, and a polarization beam splitter 160.

[0157] The optical component 130 is a polarization beam splitter configured to transmit only laser light having a certain polarization, unlike Figure 11 In Figure 12 , the optical component 130 can be a polarization beam splitter configured to transmit only laser light having a polarization different from the polarization of the second-2 laser light L 22 , for example, S-polarization. Thus, the second-2 laser light L 22 incident on the optical component 130 can be reflected by the optical component 130 as second-3 laser light L 23 .

[0158] As the 2nd-3rd laser L of P-polarization 23 It can be incident on a quarter-wave plate 140. According to an example of a quarter-wave plate 140, the second and third lasers L can be altered. 23 The polarized light. As an example, in the second-to-third laser L that has already passed through optical component 130... 23 During the process of passing through a quarter-wave plate 140, the 2nd and 3rd lasers L 23 The polarized light can be changed from P-polarized light to circularly polarized light. The second and third lasers, L, are converted to circularly polarized light. 23 It can be incident on the second optical system 30. The second-third laser L that has passed through the second optical system 30 23 The light can be emitted as a third laser L3. The third laser L3 can be reflected by the reflecting component 50 as a fourth laser L4. According to one example, the quarter-wave plate 140 can change the polarization of the fourth laser L4. As an example, the fourth laser L4 reflected by the reflecting component 50 can be changed from circularly polarized to S-polarized as it passes through the quarter-wave plate 140 again.

[0159] The fourth laser L4, converted to S-polarization, can pass through optical component 130 and be incident on the third optical system 150. The fourth laser L4 incident on the third optical system 150 can be emitted as the fifth laser L5 after passing through the third optical system 150 and then incident on the second wavefront sensor 120.

[0160] The process and reference of obtaining first wavefront information and second wavefront information using the first wavefront sensor 110 and the second wavefront sensor 120, and calculating wavefront aberration based on the first wavefront information and the second wavefront information. Figure 11 The content described is essentially the same, so it will not be repeated here.

[0161] Figure 13 This is a schematic diagram of a laser processing apparatus according to one embodiment. Figure 14 This is a schematic diagram of a laser processing apparatus according to one embodiment.

[0162] Reference Figure 13 and Figure 14 According to an example laser processing apparatus 1, a spatial light modulator (SLM) 180 may be included, which is configured to modulate the characteristics of a first laser L1. Other configurations besides the spatial light modulator 180 are referenced. Figure 8 and Figure 10 The components described are essentially the same, therefore, they will not be repeated here.

[0163] For reference Figure 8 and Figure 10The sensor 101 can receive first wavefront information and second wavefront information measured by the first wavefront sensor 110 and the second wavefront sensor 120, respectively. The processor 101 can calculate a wavefront aberration of the second optical system 30 using the first wavefront information and the second wavefront information.

[0164] According to one example, the processor 101 can control the spatial light modulator 180 to modulate a characteristic of the first laser light L1 according to the calculated wavefront aberration of the second optical system 30. As an example, the spatial light modulator 180 can modulate at least one of the amplitude or the phase of the first laser light L1 so that the wavefront aberration of the second optical system 30 is equal to or less than a certain aberration. The wavefront aberration can also be zero.

[0165] As an example, the processor 101 can calculate the wavefront aberration of the second optical system 30 using a Zernike polynomial. For example, the first wavefront information and the second wavefront information measured by the first wavefront sensor 110 and the second wavefront sensor 120, respectively, can be analyzed by a Zernike polynomial. Various forms of wavefront aberration, defocus, astigmatism, coma, etc. can be mathematically expressed by a Zernike polynomial, and the size and type of the wavefront aberration can be quantitatively calculated based thereon.

[0166] The spatial light modulator 180 can modulate at least one of the amplitude or the phase of the first laser light L1 according to the Zernike polynomial. According to one example, in a case where the spatial light modulator 180 modulates at least one of the amplitude or the phase of the first laser light L1 so that the wavefront aberration of the second optical system 30 is equal to or less than a predetermined value, for example, is changed to zero, the first laser light L1 adjusted by the spatial light modulator 180 can be set as standard light.

[0167] According to one example, the laser light irradiated by the laser source 10 performs a micro-machining process, a slotting process, a drilling process, a surface treatment process on the workpiece M by providing high-power energy to the workpiece M. Depending on the type of the workpiece M and the machining process, the shape of the third laser light L3 incident on the workpiece M and the degree of light quality of the third laser light L3 can be different. The spatial light modulator 180 can modulate the characteristics of the first laser light L1 from the standard light so that the wavefront aberration of the second optical system 30 increases or decreases according to the machining purpose of the laser machining device 1 and the workpiece M. In other words, the third laser light L3 reflecting the wavefront aberration can be formed by setting the first laser light L1 in which the wavefront aberration in the second optical system 30 is equal to or less than a predetermined value, for example, zero, as standard light and modulating at least one of the characteristics of the first laser light L1 as standard light, for example, at least one of the amplitude or the phase of the first laser light L1.

[0168] As an example, when an input value for modulating a characteristic of the first laser Ll, which is a standard laser light, such as at least one of the amplitude or the phase of the first laser Ll, is input to the spatial light modulator 180, it is possible to confirm whether the third laser L3 reflecting the wavefront aberration is output according to the input value. In a case where the data indicates that the third laser L3 reflecting the wavefront aberration is output according to the input value for modulating at least one of the amplitude or the phase of the first laser Ll, the spatial light modulator 180 can also differently change the shape of the third laser L3 or the variable curve of the third laser L3 with respect to the characteristic of the first laser Ll, such as at least one of the amplitude or the phase of the first laser Ll. At this time, the shape of the third laser L3 or the variable curve of the third laser L3 modulated using the spatial light modulator 180 can be obviously differently decided according to the machining purpose of the laser machining device 1.

[0169] According to the exemplary embodiments of the present application, it is possible to provide a laser machining device configured to measure a wavefront aberration generated by an optical system through which laser light is transmitted.

[0170] Also, in the laser light transmitted through the plurality of optical systems, the wavefront measurement position is set to a position that is the emission hole of the transmission optical system while being the incidence hole of the machining optical system, and thus it is possible to provide a laser machining device configured to measure a wavefront aberration generated by each optical system.

[0171] Also, the laser light is reflected toward the wavefront measurement position using a reflection member, and thus it is possible to provide a laser machining device configured to measure a wavefront aberration of an optical system disposed to face a workpiece to be machined.

[0172] Also, the wavefront information of the wavefront measurement position is transmitted to the wavefront sensor using the transmission optical system, and thus it is possible to provide a laser machining device that is miniaturized because the configuration of the measurement device for measuring the wavefront aberration of the measurement optical system is simplified.

[0173] Also, the wavefront aberration of the measured laser light is corrected using a spatial light modulator, and thus it is possible to provide a laser machining device configured to correct a characteristic of laser light distorted by an optical system.

[0174] Also, it is possible to provide a laser device configured to set laser light that has been corrected for a wavefront aberration as a standard laser light and intentionally further reduce or further increase a thin face aberration to change a characteristic of the laser light using a spatial light modulator.

[0175] The above description of the present application is merely provided for the purpose of illustration, and those skilled in the art can understand that the present application can be modified in other specific forms without changing the technical idea or essential characteristics of the present application. Therefore, the above-described embodiments are understood to be illustrative in all aspects, rather than restrictive.

[0176] It is to be understood that the scope of the application is indicated by the appended claims rather than by the foregoing description, and that all changes and modifications which come within the meaning and range of equivalents of the claims are intended to be embraced therein.

Claims

1. A laser processing apparatus, comprising: A laser source, configured to emit a first laser; A first optical system, wherein the first laser is incident on the first optical system and is emitted by the first optical system as a second laser; A second optical system, wherein the second laser is incident on the second optical system and is emitted by the second optical system as a third laser; A first wavefront sensor is configured to measure first wavefront information of the second laser; A second wavefront sensor is used to reflect the third laser as a fourth laser, and the second wavefront sensor is configured to measure second wavefront information of the fourth laser. as well as A processor configured to use the first wavefront information and the second wavefront information to calculate the wavefront aberrations of the second optical system.

2. The laser processing apparatus according to claim 1, further comprising: A first optical component is configured to allow the second laser to be incident on the first wavefront sensor; as well as A second optical component is configured to direct the fourth laser beam onto the second wavefront sensor.

3. The laser processing apparatus according to claim 2, wherein, The wavefront measurement positions for measuring the first wavefront information and the second wavefront information are the same, and... The wavefront measurement position is arranged between the first optical component and the second optical component.

4. The laser processing apparatus according to claim 3, wherein, The first distance (1-1) between the first optical component and the first wavefront sensor and the first distance (1-2) between the first optical component and the wavefront measurement position are the same. The second optical component and the second wavefront sensor have the same second-1 distance and the second optical component and the wavefront measurement position have the same second-2 distance.

5. The laser processing apparatus according to claim 2, wherein, The first optical component and the second optical component are polarizing beam splitters, and, The laser processing apparatus further includes a quarter-wave plate disposed between the second optical component and the second optical system.

6. The laser processing apparatus according to claim 1, further comprising: An optical component is configured to split the second laser into a second-1 laser and a second-2 laser, wherein the second-1 laser is incident on the first wavefront sensor, and the second-2 laser is incident on the second optical system, wherein... The optical components are configured to allow the fourth laser to be incident on the second wavefront sensor.

7. The laser processing apparatus according to claim 6, wherein, The wavefront measurement position is set at a location where the first-1 distance between the optical component and the first wavefront sensor is the same as the first-2 distance between the optical component and the wavefront measurement position. The wavefront measurement position is arranged between the optical component and the second optical system.

8. The laser processing apparatus according to claim 7, wherein, The second wavefront sensor is arranged to be spaced apart from the wavefront measurement position by a third distance.

9. The laser processing apparatus according to claim 8, wherein, The processor is configured to correct the second wavefront information based on the third distance using a beam propagation method.

10. The laser processing apparatus according to claim 6, wherein, The optical component is a polarizing beam splitter, and, The laser processing apparatus further includes a quarter-wave plate disposed between the optical component and the second optical system.

11. The laser processing apparatus according to claim 1, further comprising: An optical component configured to split the second laser into a second-1 laser and a second-2 laser, the second-1 laser incident on the first wavefront sensor and the second-2 laser incident on the second optical system; as well as A third optical system is configured to emit the fourth laser incident via the optical components as a fifth laser incident on the second wavefront sensor.

12. The laser processing apparatus according to claim 11, wherein, The wavefront measurement locations for the first and second wavefront information are the same, and... The wavefront measurement position is arranged between the optical component and the second optical system.

13. The laser processing apparatus according to claim 12, wherein, The first-1 distance between the optical component and the first wavefront sensor and the first-2 distance between the optical component and the wavefront measurement position are the same, and, The third wavefront information of the fifth laser incident on the second wavefront sensor is the same as the second wavefront information of the fourth laser.

14. The laser processing apparatus according to claim 13, wherein, The optical component is a polarizing beam splitter, and, The laser processing apparatus further includes a quarter-wave plate disposed between the optical component and the second optical system.

15. The laser processing apparatus according to claim 13, wherein, The third optical system is a transmission optical system.

16. The laser processing apparatus according to claim 1, further comprising: A spatial light modulator (SLM) is configured to modulate the characteristics of the first laser based on the wavefront aberration of the second optical system.

17. The laser processing apparatus according to claim 16, wherein, The spatial light modulator is configured to modulate the characteristics of the first laser so that the wavefront aberration is equal to or less than a predetermined aberration.

18. The laser processing apparatus according to claim 17, wherein, The first laser, after wavefront aberration correction in the spatial light modulator, is set as the standard light, and... The spatial light modulator is configured to modulate the first laser based on the characteristics of the standard light, thereby increasing or decreasing the wavefront aberration of the second optical system.

19. The laser processing apparatus according to claim 1, further comprising a reflective element, wherein the third laser is incident on the reflective element and the reflective element reflects the fourth laser.

20. The laser processing apparatus according to claim 19, wherein, The reflective component or at least one of the second optical systems is moved so that the reflective component faces the second optical system.

21. The laser processing apparatus according to claim 19, wherein, The reflective component includes at least one of a plane mirror or a curved mirror.

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