Laser generator, laser drilling device, and laser cutting device
By separating the beam shaping unit from the beam conversion unit, the processing difficulty and cost of the laser generator are reduced, the laser energy utilization rate and beam stability are improved, and the efficiency of laser drilling and cutting is enhanced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- BYD CO LTD
- Filing Date
- 2025-03-31
- Publication Date
- 2026-07-14
AI Technical Summary
The beam shaping device in existing laser generators requires high structural precision, which increases the difficulty and cost of manufacturing.
The beam shaping unit and the beam conversion unit are set up separately. The beam shaping unit shapes the Gaussian beam into a ring beam, and then the beam conversion unit converts it into a Bessel beam, which reduces the accuracy requirements of the beam shaping device.
It reduces the processing difficulty and hardware cost of laser generators, improves laser energy utilization and beam stability, and enhances the efficiency of laser drilling and cutting.
Smart Images
Figure CN224502628U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of laser technology, and in particular to a laser generator, a laser drilling device, and a laser cutting device. Background Technology
[0002] With the continuous development of technology, the technology of using laser beams to cut and drill workpieces has been more widely applied. For example, some laser cutting and laser drilling devices are equipped with laser generators to produce laser light.
[0003] To improve the quality of drilling and cutting, laser generators are usually equipped with beam shaping devices. These devices can convert the Gaussian beam provided by the laser source into a Bessel beam with a longer focal depth range, a smaller spot size, and no diffraction characteristics.
[0004] However, existing beam shaping devices require high precision in their structural implementation, which increases the manufacturing difficulty of the beam shaping devices. Utility Model Content
[0005] This application provides a laser generator, a laser drilling device, and a laser cutting device to reduce the precision requirements of the structure in the beam shaping device and reduce the processing difficulty of the beam shaping device.
[0006] The first aspect of this application provides a laser generator, comprising: a laser source for generating a Gaussian beam; a beam shaping unit for shaping the Gaussian beam into a ring beam; and a beam conversion unit for converting the ring beam into a Bessel beam.
[0007] In one embodiment of the first aspect of this application, the optical axes of the beam conversion unit and the beam shaping unit coincide.
[0008] In one embodiment of the first aspect of this application, the beam shaping unit includes an annular aperture.
[0009] In one embodiment of the first aspect of this application, the beam shaping unit includes a diffractive optical element (DOE).
[0010] In one embodiment of the first aspect of this application, the phase of the annular beam gradually decreases with a preset gradient in the direction from the annular center to the annular edge.
[0011] In one embodiment of the first aspect of this application, the beam shaping unit includes a plurality of phase adjustment structures stacked together, all of which are annular and whose centers coincide with the optical axis.
[0012] In one embodiment of the first aspect of this application, the radius of the plurality of phase adjustment structures gradually increases in the optical axis direction.
[0013] In one embodiment of the first aspect of this application, the beam conversion unit includes an axial cone mirror.
[0014] In one embodiment of the first aspect of this application, the base angle of the beam conversion unit is related to the depth of focus of the Bessel beam.
[0015] The distance between the beam shaping unit and the beam conversion unit in the optical axis direction is less than or equal to 100 mm.
[0016] In one embodiment of the first aspect of this application, the focal depth range is 10mm-30mm.
[0017] In one embodiment of the first aspect of this application, the base angle of the beam conversion unit is less than or equal to 60 degrees.
[0018] In one embodiment of the first aspect of this application, the diameter of the beam conversion unit is less than 300 mm.
[0019] In one embodiment of the first aspect of this application, the wavelength of the Gaussian beam is less than 20,000 nm.
[0020] In one embodiment of the first aspect of this application, the material of the beam conversion unit includes fused silica.
[0021] In one embodiment of the first aspect of this application, the parameters of the beam conversion unit are based on the depth of focus L of the Bessel beam. B Substitute into the following formula:
[0022]
[0023] L B =w[(tan(β) -1 )-tan(γ)]
[0024]
[0025] Among them, R b Let γ be the radius of the Bessel beam perpendicular to the optical axis, γ be the base angle of the beam conversion unit, w be the beam waist radius of the Gaussian beam, and β = arcsin(n a sin(γ))-γ,n a Let k be the refractive index of the beam conversion unit and k0 be the wavenumber. λ is the wavelength of the Gaussian beam, R2 is the outer radius of the annular beam, and R1 is the inner radius of the annular beam.
[0026] In one embodiment of the first aspect of this application, the laser generator further includes an antireflective coating disposed on the incident light side of the axial cone mirror for filtering out stray light from the annular beam.
[0027] A second aspect of this application provides a laser drilling apparatus, including a laser generator as described in any of the first aspects of this application.
[0028] A third aspect of this application provides a laser cutting apparatus, including a laser generator as described in any of the first aspects of this application.
[0029] The laser generator, laser drilling device, and laser cutting device provided in this application include a laser generator comprising a laser source, a beam shaping unit, and a beam conversion unit. The beam shaping unit shapes the Gaussian beam generated by the laser source into a ring beam, and the beam conversion unit converts the ring beam into a Bessel beam. By separating the beam shaping unit and the beam conversion unit within the laser generator, compared to using a single unit to convert the Gaussian beam into a Bessel beam, the processing difficulty of the laser generator is reduced, thereby lowering both the hardware and processing costs. Attached Figure Description
[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0031] Figure 1 This is a schematic diagram illustrating the application scenario of this application;
[0032] Figure 2 This is a schematic diagram of the structure of a beam shaping component in the prior art;
[0033] Figure 3 This is a schematic diagram of the structure of a diffraction axis cone in the prior art;
[0034] Figure 4 This is a schematic diagram of the structure of an embodiment of the laser generator provided in this application;
[0035] Figure 5 This is a schematic diagram of another embodiment of the laser generator provided in this application.
[0036] Figure 6 A schematic diagram of the annular beam for DOE conversion provided in this application;
[0037] Figure 7A schematic diagram of the energy density of the ring beam provided in this application;
[0038] Figure 8 A schematic diagram of the structure of an embodiment of the DOE provided in this application;
[0039] Figure 9 A schematic diagram of the energy density of the Bessel beam provided in this application;
[0040] Figure 10 This is a schematic diagram of the energy density of a Bessel beam obtained when the ring beam passes through an axial conical mirror but not through a DOE.
[0041] The accompanying drawings have illustrated specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to specific embodiments. Detailed Implementation
[0042] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0043] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0044] Figure 1 This is a schematic diagram illustrating the application scenario of this application, such as... Figure 1 As shown, with the continuous development of technology, the technology of using laser beams to process workpieces has been more widely applied. This application is applied in scenarios where laser beams are needed to process workpiece 2, such as... Figure 1 The laser generator 1 in the process is used to generate a laser beam and emit the laser beam to the workpiece 2 to be processed, thereby processing the workpiece 2.
[0045] For example, in a specific application scenario, a laser drilling device includes, for instance, the following components: Figure 1 The laser generator 1, as described above, generates a laser beam that can be used to drill holes in the workpiece 2 to be processed. For example, in another specific application scenario, the laser cutting device includes, as shown below... Figure 1 The laser generator 1 can be used to cut the workpiece 2 to be processed.
[0046] Specifically, such as Figure 1 The laser generator 1 shown includes a laser source 101 and a beam shaping assembly 102. The laser source 101 generates a Gaussian laser beam, hereinafter referred to as a Gaussian beam. The laser source 101 emits the Gaussian beam to the beam shaping assembly 102, which shapes the Gaussian beam before emitting the shaped laser beam to the workpiece 2. The beam-shaped laser beam improves the processing quality when drilling, cutting, or performing other operations on the workpiece 2.
[0047] A Bessel beam in a laser beam possesses the characteristics of being non-diffractive and maintaining consistent intensity within a certain axial range. This characteristic allows Bessel beams to be better applied in laser beam processing fields such as laser drilling and cutting. Therefore, the beam shaping component 102 can be specifically used to convert a Gaussian beam into a Bessel beam with a longer focal depth range, a smaller spot size, and non-diffractive properties.
[0048] Figure 2 This is a schematic diagram of the structure of a beam shaping component in the prior art, such as... Figure 2 The beam shaping assembly 102 shown includes a diffraction axis cone 10201 and a focusing mirror 10202. The diffraction axis cone 10201 shapes the Gaussian beam, and the focusing mirror 10202 focuses the beam to form a Bessel beam.
[0049] Figure 3 This is a schematic diagram of the structure of a diffraction axis cone in the prior art, such as... Figure 3 As shown, since the diffraction axis cone 1021 needs to provide diffraction function, the apex angle α of the diffraction axis cone 1021 needs to be designed according to the laser beam. Once the angle of the apex angle α is deviated, the generated Bessel beam will have a large error.
[0050] Therefore, as Figure 2 and Figure 3In the prior art shown, the diffraction axis cone 1021 of the beam shaping component 102 requires high structural precision, which increases the processing difficulty of the diffraction axis cone 1021 and its associated beam shaping component 102 and laser generator 1, thereby increasing the hardware cost and processing cost of the diffraction axis cone 1021 and its associated beam shaping component 102 and laser generator 1.
[0051] Based on this, this application provides a laser generator to overcome the technical problems of high structural accuracy and high processing difficulty in the existing laser generator, which includes a beam shaping component 102 that can be used to convert a Gaussian beam into a Bessel beam.
[0052] The technical solutions of this application will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.
[0053] Figure 4 This is a schematic diagram of the structure of an embodiment of the laser generator provided in this application, as shown below. Figure 4 The laser generator 1 shown can be applied to, for example... Figure 1 In the scenario shown. Specifically, as Figure 4 The laser generator 1 shown includes a laser source 101, a beam shaping unit 1021, and a beam conversion unit 1022. The laser source 101 generates a Gaussian beam G1 and emits it to the beam shaping unit 1021. The beam shaping unit 1021 shapes the Gaussian beam G1 into a ring beam and emits it to the beam conversion unit 1022. The beam conversion unit 1022 converts the ring beam G1 into a Bessel beam G2.
[0054] In this embodiment, since the beam shaping unit 1021 and the beam conversion unit 1022 are set separately, compared with the laser generator 1 converting the Gaussian beam into a Bessel beam through a single unit, the working requirements and processing difficulty of each unit in the laser generator 1 are reduced, thus reducing the overall processing difficulty of the laser generator 1, and consequently reducing the hardware cost and processing cost of the laser generator.
[0055] More specifically, Figure 5 A schematic diagram of another embodiment of the laser generator provided in this application is shown below. Figure 5 It shows Figure 4 One specific implementation method of a laser generator.
[0056] Among them, such as Figure 5The beam shaping unit 101 shown includes diffractive optical elements (DOEs). DOEs have higher light energy utilization and can improve the energy utilization of the laser generator 1.
[0057] like Figure 5 The beam conversion unit 1022 shown includes an axicon. When the beam is converted, the axicon produces a Bessel beam with a deeper depth of focus and no diffraction characteristics, which can improve the stability of the Bessel beam generated by the laser generator 1.
[0058] Furthermore, such as Figure 5 In the laser generator 1 shown, the laser source 101, DOE 1021, and axial conical mirror 1022 are arranged sequentially, and the optical axes of DOE 1021 and axial conical mirror 1022 coincide. Figure 5 In the example shown, the optical axes of the laser source 101, DOE 1021, and axial conical mirror 1022 are all in the direction from left to right as indicated by the dashed line z. When the optical axes of DOE 1021 and axial conical mirror 1022 coincide, the energy distribution of the Bessel beam output through axial conical mirror 1022 is more concentrated, which can ensure the efficiency of the Bessel beam generated by laser generator 1 during subsequent drilling and cutting.
[0059] When the laser source 101 emits a Gaussian beam along the optical axis z toward the incident side of the DOE 1021, the DOE 1021 can be used to convert the incident Gaussian beam G1 into a ring beam G2. The exit side of the DOE 1021 is opposite to the incident side of the axial conical mirror 1022, so that the ring beam G2 is emitted along the optical axis z to the incident side of the axial conical mirror 1022. The axial conical mirror 1022 can be used to convert the incident ring beam G2 into a Bessel beam G3, and emit the Bessel beam G3 along the optical axis z through its exit side.
[0060] Figure 6 This is a schematic diagram of the annular beam of DOE conversion provided in this application, combined with... Figure 5 and Figure 6 As shown, DOE1021 can be used to convert a Gaussian beam G1 into a ring beam G2, where the inner radius of the ring beam G2 is R1 and the outer radius is R2.
[0061] In one embodiment, such as Figure 6 The energy density of the annular beam G2 shown gradually changes between the inner radius R1 and the outer radius R2. Specifically, in the y-direction from the annular center O on the inner side of the annulus to the annular edge on the outer side, the energy density of the annular beam G2 gradually decreases with a preset gradient. Therefore, by setting the gradient of the annular beam, the axial cone mirror 1022 does not need to... Figure 3The angle is set in the manner shown, thereby reducing the processing difficulty of the shaft cone mirror 1022, and thus reducing the hardware cost and processing cost of the shaft cone mirror 1022.
[0062] For example, Figure 7 This is a schematic diagram of the energy density of the ring beam provided in this application, where P1 is the energy density of the ring beam G2 in the z-axis direction, and P2 is the energy density of the ring beam G2 in the y-axis direction. Combined with... Figure 5 and Figure 7 As shown, the energy of the ring beam is concentrated between the inner radius R1 and the outer radius R2 within the ring region. Furthermore, along the y-direction from the inner radius R1 to the outer radius R2, the energy density of the ring beam G2 gradually decreases from approximately 1 to approximately 0 with a preset gradient. It should be noted that... Figure 7 The gradient changes of energy density from 1, 0.8, 0.6, 0.4, 0.2 to 0 are merely examples; energy density can also be gradually varied with other gradients, all of which are within the scope of protection of this application.
[0063] In order to obtain such Figure 6 and Figure 7 Regarding the annular beam G2, this application also provides a specific implementation of DOE1021. For example, Figure 8 A schematic diagram of the structure of an embodiment of the DOE provided in this application is shown below. Figure 8 The DOE1021 shown includes multiple phase adjustment structures 10210 stacked together. Each of the multiple phase adjustment structures 10210 is ring-shaped, with the same center point O in the figure. Point O also coincides with the optical axis z of the DOE1021. This embodiment does not limit the number of phase adjustment structures 10210 included in the DOE1021. The design of the DOE1021 can be 8 steps, 16 steps, 32 steps, or continuous steps, etc. The DOE1021 implemented using the phase adjustment structures 10210 provided in this embodiment has a relatively simple structure, thereby reducing the implementation cost and difficulty of the DOE1021 and its associated laser generator 1.
[0064] Specifically, in order to achieve such Figure 7 The ring beam G2 shown has a certain gradient in energy density, such as Figure 8 In the DOE1021 shown, the radii of the multiple phase adjustment structures 10210 gradually increase along the optical axis z. Figure 8As can be seen in the y-direction perpendicular to the optical axis z, the radii of the multiple phase adjustment structures 10210 gradually increase along the optical axis z. When the laser beam passes through a phase adjustment structure 10210, its phase changes, resulting in a change in energy density. Therefore, by stacking multiple phase adjustment structures 10210, when the radii of the multiple phase adjustment structures 10210 change with a preset gradient, a ring beam G2 with energy density gradually changing with the same preset gradient can be obtained.
[0065] Figure 9 A schematic diagram of the energy density of the Bessel beam provided in this application is shown below. Figure 9 As shown, P3 represents the energy density of Bessel beam G3 in the energy range of 0-40, P4 represents the energy density of Bessel beam G3 in the direction perpendicular to the energy range of 0-40, and P5 represents the energy density of Bessel beam G3 in the y-direction. It can be seen that the energy density of Bessel beam G3 is concentrated between Y1 and Y2 in the energy range, exhibiting a high energy concentration.
[0066] In contrast. Figure 10 This is a schematic diagram of the energy density of a Bessel beam obtained when the ring beam passes through the axial conic mirror but not through the DOE. The Bessel beam G3 is not concentrated in a specific region within the energy range of 0-40, and its energy concentration is poor.
[0067] Therefore, in this embodiment, after the Gaussian beam is converted into a ring beam G2 by the DOE 1021, the axial conical mirror 1022 performs axial optical field modulation on the Gaussian beam G2 to obtain a Bessel beam G3. The DOE 1021 modulates the optical field of the Gaussian beam so that the optical field distribution of the laser beam reaching the incident side of the axial conical mirror 1022 is consistent with the optical field distribution generated after the Gaussian beam is cut off by the ring slit. This provides the theoretical basis for axial optical field modulation based on the combination of the ring slit and the axial conical mirror 1022. The DOE 1021 generates a function similar to the ring slit to modulate the optical field, achieving an axially adjustable and uniform optical field distribution. This results in the Bessel beam G3 obtained by the axial conical mirror 1022 based on the ring beam G2 having a high energy concentration, thereby effectively improving the energy utilization rate and beam shaping effect of the laser beam.
[0068] In summary, in the laser generator 1 provided in this embodiment, the DOE 1021 can be used to convert the Gaussian beam G1 generated by the laser source 101 into a ring beam G2 with a certain gradient. Subsequently, the axial conical mirror 1022 can be used to convert the ring beam G2 into a Bessel beam G3, and the Bessel beam G3 has a uniform intensity distribution along the optical axis z. Since the DOE 1021 and the axial conical mirror 1022 in the laser generator 1 are separately set, it is not necessary to set the apex angle α of the axial conical mirror 1022 accordingly. Even if the apex angle α of the axial conical mirror 1022 has a certain deviation, the generated Bessel beam G3 will not have a large error. Figure 2 Compared with the prior art shown, the laser generator 1 provided in this application embodiment reduces the structural precision requirements of the axial cone mirror 1022, thereby reducing the processing difficulty of the axial cone mirror 1022 and the laser generator 1, and further reducing the hardware cost and processing cost of the axial cone mirror 1022 and the laser generator 1.
[0069] The laser generator 1 provided in this application embodiment has a high laser energy utilization rate, and the provided Bessel beam G3 has a uniformly distributed long focal depth effect in the optical axis z direction, which can be more effectively used in laser cutting, drilling and other scenarios of glass materials to cut and drill glass of different thicknesses.
[0070] In one embodiment, the laser generator 1 provided in this application is further provided with an anti-reflection film on the light-incident side of the beam conversion unit 1022, which is used to filter out stray light when the axial conical mirror 1022 receives the ring beam G2, thereby further ensuring the effectiveness of the Bessel beam G3 output by the axial conical mirror 1022.
[0071] In a specific embodiment, the antireflection coating can be set according to the wavelength of the laser beam. For example, when the wavelength of the Gaussian beam G1 is 1064nm, the surface of the incident side of the axial conical lens 1022 can be coated with an antireflection coating with a wavelength of 1064nm, thereby reducing the influence of stray light generated when the DOE 1021 processes the Gaussian beam G1 to obtain the ring beam G2 on the axial conical lens 1022. In addition, the antireflection coating can more effectively control the size of the ring region of the ring beam G2 from the incident side of the axial conical lens 1022.
[0072] In one embodiment, the Gaussian beam can be set to 1064nm, 1030nm, etc. based on the wavelength of the laser. In addition, the laser generator 1 provided in this application can also support other Gaussian beams with wavelengths less than 20000nm, making the laser generator 1 provided in this application have a wider range of application scenarios.
[0073] In one embodiment, the settings of parameters such as the base angle of the axial cone mirror 1022 provided in this application are related to the depth of focus L of the Bessel beam G3.B This improves the flexibility and effectiveness of parameter settings.
[0074] Specifically, the parameters of the axis-cone mirror 1022 can be determined based on the focal depth L of the Bessel beam. B Substituting into formulas one through five below, we get:
[0075]
[0076] L B =w[(tan(β) -1 Formula 2
[0077]
[0078] Among them, R b Let γ be the radius of the Bessel beam G3 perpendicular to the optical axis z, γ be the base angle of the axial conic mirror 1022, w be the beam waist radius of the Gaussian beam G2, and β = arcsin(n a sin(γ))-γ,n a Let be the refractive index of the 1022 axial conical mirror, and k0 be the wavenumber. λ is the wavelength of the Gaussian beam G1, R2 is the outer radius of the annular beam G2, and R1 is the inner radius of the annular beam G2.
[0079] Combining formulas one through five above, it can be seen that the lateral resolution of the axial cone 1022 is mainly determined by the base angle γ of the axial cone.
[0080] Table 1
[0081]
[0082] Table 2
[0083] Base angle / degrees Size / mm Material 10 φ20 Fused Silica
[0084] For example, Table 1 shows a parameter setting method for a laser source 101, and Table 2 shows a parameter setting method for an axial conical mirror 1022. Combining the parameters in Table 1 and Formulas 1 to 5, the distance between DOE 1021 and axial conical mirror 1022 in the optical axis z direction is set to 100mm. The distance between DOE 1021 and axial conical mirror 1022 can be set according to the engineering requirements of the laser generator 1, for example, to 50mm, 100mm, or 200mm. Furthermore, when necessary, the distance between DOE 1021 and axial conical mirror 1022 can also be set to 1000mm or 2000mm. In this embodiment, the distance between DOE 1021 and axial conical mirror 1022 can be set to less than or equal to 100mm, thereby increasing the compactness of the internal components of the laser generator 1 and reducing the size of the laser generator 1.
[0085] Furthermore, as shown in Table 1, calculations are performed for positions with a focal depth range of 10mm-30mm for the Bessel beam, resulting in the parameters of the axial cone 1022 in Table 2.
[0086] In one embodiment, the base angle of the axial cone mirror 1022 can be set to less than or equal to 60 degrees. The base angle can be set according to the requirements of the Bessel beam. When determining the base angle of the axial cone mirror, the largest angle that meets the requirements of the Bessel beam can be selected to reduce the manufacturing difficulty of the axial cone mirror 1022. In the embodiment shown in Table 1 of this application, the base angle of the axial cone mirror 1022 is 10 degrees.
[0087] In one embodiment, the diameter of the axial conical mirror 1022 is less than 300 mm. In the embodiment shown in Table 1 of this application, the diameter of the axial conical mirror 1022 is 20 mm. Setting the diameter of the axial conical mirror 1022 to be smaller can effectively reduce the volume of the laser generator 1.
[0088] Among them, the base angle γ and refractive index n of the axial conical mirror 1022 a Once determined, C calculated using Formula 4 is a constant. For example, when the base angle of the axial cone 1022 is 10 degrees, the calculated spot diameter of the Bessel beam G3 is 10 μm, and the focal depth L of the Bessel beam... B It is 11.7mm.
[0089] In another embodiment of the application, the beam shaping unit 1021 in the laser generator 1 may also include an annular aperture, which can form an annular beam with good axial distribution based on the Gaussian beam. In this case, the structure of the laser generator 1 is relatively simple, making the laser generator 1 cheaper and easier to implement.
[0090] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.
[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
Claims
1. A laser generator, characterized in that, include: A laser source (101) is used to generate a Gaussian beam; A beam shaping unit (1021) is used to shape the Gaussian beam into a ring beam, wherein the energy density of the ring beam gradually decreases with a preset gradient in the direction from the ring center to the ring edge. A beam conversion unit (1022) is used to convert the annular beam into a Bessel beam.
2. The laser generator according to claim 1, characterized in that, The optical axes of the beam conversion unit (1022) and the beam shaping unit (1021) coincide.
3. The laser generator according to claim 1 or 2, characterized in that, The beam shaping unit (1021) includes an annular aperture.
4. The laser generator according to claim 1 or 2, characterized in that, The beam shaping unit (1021) includes a diffractive optical element (DOE).
5. The laser generator according to claim 2, characterized in that, The beam shaping unit (1021) includes multiple phase adjustment structures (10210) stacked together. All of the multiple phase adjustment structures (10210) are annular, and the center of each annular structure coincides with the optical axis.
6. The laser generator according to claim 5, characterized in that, In the optical axis direction, the radius of the plurality of phase adjustment structures (10210) gradually increases with the preset gradient.
7. The laser generator according to claim 1 or 2, characterized in that, The beam conversion unit (1022) includes an axial cone mirror.
8. The laser generator according to claim 7, characterized in that, The settings of the beam conversion unit (1022) are related to the depth of focus of the Bessel beam.
9. The laser generator according to claim 8, characterized in that, The distance between the beam shaping unit (1021) and the beam conversion unit (1022) in the optical axis direction is less than or equal to 100 mm.
10. The laser generator according to claim 8, characterized in that, The focal depth of the Bessel beam is in the range of 10mm-30mm.
11. The laser generator according to claim 8, characterized in that, The base angle of the beam conversion unit (1022) is less than or equal to 60 degrees.
12. The laser generator according to claim 8, characterized in that, The diameter of the beam conversion unit (1022) is less than 300 mm.
13. The laser generator according to claim 8, characterized in that, The material of the beam conversion unit (1022) includes fused silica.
14. The laser generator according to claim 8, characterized in that, The wavelength of the Gaussian beam is less than 20,000 nm.
15. The laser generator according to claim 8, characterized in that, The parameters of the beam conversion unit (1022) are set according to the depth of focus of the Bessel beam using the following formula: Among them, R b Let γ be the radius of the Bessel beam perpendicular to the optical axis, γ be the base angle of the beam conversion unit (1022), and w be the waist radius of the Gaussian beam. n a The refractive index of the beam conversion unit (1022) is given by k, and the wavenumber is given by k0. λ is the wavelength of the Gaussian beam, R2 is the outer radius of the annular beam, and R1 is the inner radius of the annular beam.
16. The laser generator according to claim 1 or 2, characterized in that, Also includes: An antireflection coating is disposed on the incident light side of the beam conversion unit (1022) to filter out stray light from the annular beam.
17. A laser drilling device, characterized in that, Including the laser generator (1) as described in any one of claims 1-16.
18. A laser cutting device, characterized in that, Including the laser generator (1) as described in any one of claims 1-16.