Collimating, focusing and shaping integrated optical element, laser and laser processing device
The beam collimation, focus and shaping is achieved through a single optical element, which solves the problems of uneven beam energy distribution and complex optical shaping components in existing laser processing, and achieves uniform distribution and efficient processing of the beam within the Rayleigh range.
Patent Information
- Application Number
- CN202510572707.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-06
- Publication Date
- 2025-08-15
AI Technical Summary
In the existing laser processing technology, the uneven axial energy distribution of the light beam leads to low processing efficiency and processing defects, and the existing optical shaping components are complex, costly and poor reliability.
Using an optical element that integrates collimation, focusing and shaping of the original beam through a single optical element, outputs a telephoto-depth shaping beam, simplifying the optical path structure.
The axial intensity distribution of the beam in the Rayleigh range is achieved, which improves processing efficiency and effect, reduces the complexity and cost of the optical system, and improves reliability.
Smart Images
Figure CN120491327A_ABST
Abstract
Description
Technical field
[0001] The present application relates to the field of laser processing, and in particular to an optical element, a laser and a laser processing device that integrates collimation, focusing and shaping. [Background Technology]
[0002] High-power fiber lasers are increasingly being used in the field of materials processing. Lasers have the advantage of concentrated energy, but the energy density drops rapidly away from the focal point in the axial direction of the laser beam. This can cause significant uneven energy distribution across the thickness of the processed material, reducing processing efficiency and effectiveness. If the energy at the focal point is too high, the material overheats, causing vaporization and plasma formation, while the energy density away from the focal point is insufficient, preventing the material from being effectively liquefied or the degree of liquefaction from meeting the viscosity requirements for processing. Consequently, the material cannot be fully melted or effectively removed, resulting in processing defects such as cutting slag and welding porosity.
[0003] In the axial distribution at the focus of the processing beam, Figure 1 As shown, a person skilled in the art first converts the original light beam transmitted in the optical fiber into a spatial light beam through an end cap 1, collimates the spatial light beam with a collimator 2, and then uses a spatial optical shaping element, such as a prism 3, to form a long-focus-depth light beam. A focusing lens 4 is then set to focus the formed long-focus-depth light beam and output a shaped light beam to improve the processing effect. In some cases, an optical path deflection component is also set after the focusing lens 4 to adjust the light path. However, the preparation of spatial optical shaping elements such as prisms is difficult and costly; the optical shaping assembly composed of a collimator, prism and focusing lens requires a larger optical shaping space; the structure that uses a spatial optical path to output a shaped light beam has the characteristics of poor reliability, and its airtightness, cleanliness, structural stability, etc. all have problems, and the spatial optical coupling operation is complicated and there is a lot of stray light.
[0004] The cross-sectional refractive index distribution of the gradient refractive index lens of the prior art satisfies the function (hereinafter referred to as α distribution), where α = 2, such as Figure 2 As shown, the refractive index distribution of the gradient refractive index lens is as follows Figure 2 As shown in A, the part with constant refractive index is the protective layer; the corresponding light field distribution of the Z axis and X axis near the focus of the shaped beam is as follows Figure 2 As shown in B, it is focused on both the Z axis and the X axis. It has the characteristic of strong light intensity at the focus, but has no effect on beam shaping.
[0005] Therefore, it is necessary to design an integrated collimating, focusing and shaping optical element, laser and laser processing device, and replace the end cap, focusing mirror, corner conic mirror and collimating mirror of the existing technology with a single optical element to collimate, focus and shape the original light beam, output the shaped light beam, simplify the optical path structure and reduce space occupancy. [Summary of the invention]
[0006] This application proposes an integrated collimating, focusing and shaping optical element, laser and laser processing device to solve the problems in the prior art of complex optical shaping components required to obtain a long focal depth beam and the difficulty of preparation. A single optical element can be used to collimate, focus and shape the original light beam, reducing space occupation and outputting a shaped light beam with a long focal depth distribution, meeting the requirements of laser processing, reducing the cost of beam shaping and improving the reliability of the laser processing system. A single optical element can complete the collimation, focusing and shaping of the light beam, and the optical path structure is simple, which is conducive to the miniaturization of the laser output head.
[0007] In order to solve the above technical problems, the present application proposes an integrated collimating, focusing and shaping optical element, including an optical waveguide, the refractive index distribution of the optical waveguide is configured to radially decrease gradually from the inside to the outside; the outer side surface of the optical waveguide is configured as the outer edge of the optical element; the two bottom surfaces of the optical waveguide are respectively configured as the light receiving surface and the light output surface, and the light output surface is perpendicular to or at a specific angle to the outer side surface; the optical element is configured to collimate, focus and shape the original light beam to form a shaped light beam with a long focal depth.
[0008] Optionally, the refractive index distribution is configured to satisfy the distribution function
[0009] n(r)=n R +(n0-n R )(cos(β·r / R)+(--cos(β) / sin(β))sin(β·r / R)); wherein nR is the refractive index of the outer edge, n0 is the refractive index at the center of the optical waveguide, and r is the refractive index of any point in the optical waveguide. A The distance to the center of the optical waveguide, R is the radius of the circle formed by the plane and the outer edge of point A and its corresponding r, n(r) is the refractive index at point A; β is the gradient refractive index constant, and the value range of β is 1<β<1.95; the value range of the numerical aperture NA of the optical element is
[0010]
[0011] Optionally, the axial light intensity distribution of the shaped light beam is uniform within the Rayleigh range.
[0012] Optionally, the original beam includes a beam transmitted by an optical fiber, and the optical element receives the original beam in a manner including direct coupling with the optical fiber, coupling by optical cementing process, or fusion splicing coupling; or, the original beam is transmitted in the form of spatial light.
[0013] Optionally, the pitch P of the optical waveguide is P = 2π·R·n0 / NA; the length L of the optical waveguide is (0.25 + n / 2)P < L < (0.5 + m / 2)P, where n is a positive integer or n = 0, m is a positive integer or m = 0, and m ≥ n.
[0014] Optionally, the optical waveguide includes a columnar shape and a conical shape; an antireflection film and / or a reflection-reducing film is coated on the light receiving surface, and an antireflection film and / or a reflection-reducing film is coated on the light output surface.
[0015] Optionally, the light receiving surface is a plane or a curved surface, and the light output surface is a plane or a curved surface.
[0016] Optionally, it further includes a protective layer. The protective layer surrounds the outer side surface of the optical waveguide without a gap, and the refractive index distribution of the protective layer is represented by one or more segments of one or more functions with the outer edge as the boundary condition.
[0017] This application also provides a laser, which includes the above optical element, and further includes a laser generating device. The beam output end of the laser generating device is coupled with the beam input end of the first optical fiber through spatial optical coupling, coupling by optical cementing process, or fusion splicing coupling; the laser generating device is configured as a light source for generating the original beam; the shaped beam is configured as the output beam of the laser.
[0018] This application also provides a laser processing device, which includes the above laser, and the laser processing device is used to act the output beam on the laser processing material.
[0019] Compared with the prior art, this application has at least the following beneficial technical effects:
[0020] This application provides an optical element integrating collimation, focusing and shaping. By using a single optical element to replace the end cap, focusing mirror, corner cube mirror and collimating mirror in the prior art, it realizes collimation, focusing and shaping of the original beam, outputs the shaped beam, simplifies the optical path structure, reduces the space occupation, and solves the problems of high preparation difficulty and high cost of spatial optical shaping elements such as corner cube mirrors; the optical shaping assembly composed of a collimating mirror, a corner cube mirror and a focusing mirror requires a large optical shaping space; the structure using the spatial optical path to output the shaped beam has poor structural reliability, complex spatial optical coupling operation, and more stray light.
[0021] The collimating, focusing, and shaping integrated optical element provided by the present application extends the focal depth of the shaped light beam while achieving uniform axial light intensity distribution of the shaped light beam within the Rayleigh range, thereby obtaining better light energy utilization and processing effect for processing; the original light beam includes a spatial light beam or a light beam transmitted by an optical fiber, and the collimating, focusing, and shaping integrated optical element provided by the present application can be fixed together with the optical fiber that transmits the light beam by welding or optical glue process, further improving the reliability of the optical system, and the welding operation can be achieved using an existing welding machine, and the optical coupling is simple and convenient. In particular, the light beam transmitted by the optical fiber can be directly received and output by the optical element proposed by the present application that is welded to the optical fiber, and directly outputs a shaped light beam that can be used for laser processing. Providing a special coating that matches the refractive index of the optical waveguide on the light receiving surface and the light output surface can further improve the light transmittance of the light receiving surface and / or the light output surface, and reduce the formation of return light and stray light.
[0022] The radial refractive index distribution of the integrated collimating, focusing and shaping optical element provided by the present application is different from the refractive index distribution of the gradient refractive index lens with square index distribution in the prior art; it can realize the collimation, focusing and shaping of the original light beam, and the Rayleigh range of the output shaped light beam is greatly extended, and within the Rayleigh range, the light intensity distribution of the light beam is uniform; it also includes a curved light output surface, which can provide a better focusing effect and perform dispersion compensation on the shaped light beam.
[0023] The present application also proposes a laser that uses the optical elements provided in the present application to directly output a spatially distributed shaped light beam. The laser output head has a simple structure, good airtightness, and is easy to maintain.
[0024] This application also proposes a laser processing device. Using the optical elements and laser provided in this application, the laser processing device proposed in this application has a simple processing output head and has obvious advantages in laser processing situations where the focus position has a limited adjustable range.
Brief Description of the Drawings
[0025] One or more embodiments are exemplarily illustrated by corresponding drawings, which do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.
[0026] Figure 1 This is a schematic diagram of adding a spatial optical shaping component such as a corner cube in the optical path in the prior art;
[0027] Figure 2 This is a schematic diagram of the refractive index distribution of a radially gradient refractive index lens in the prior art and a schematic diagram of the radial and axial light field distribution at the focus of the corresponding shaped light beam;
[0028] Figure 3 This is a schematic diagram of the optical path for optical shaping of the original light beam using the optical element provided by the present application in some embodiments of the present application;
[0029] Figure 4 is a schematic diagram of a cross-sectional structure of an optical element and a corresponding refractive index distribution in some embodiments of the present application;
[0030] Figure 5 Schematic diagram of the light spot and axial intensity distribution of the output beam corresponding to the prior art α of 1.7 and the shaped beam corresponding to the refractive index distribution proposed in this application in some embodiments of the present application;
[0031] Figure 6 It is a schematic diagram of the pitch in some embodiments of the present application. [Specific implementation method]
[0032] In order to facilitate the understanding of the present application, the present application is described in more detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that when an element is described as "fixed to" another element, it can be directly on the other element, or there can be one or more centered elements therebetween. When an element is described as "electrically connected to" another element, it can be directly connected to the other element, or there can be one or more centered elements therebetween. The terms "upper", "lower", "inner", "outer", "bottom" and the like used in this specification indicate an orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" and the like are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.
[0033] Unless otherwise defined, all technical and scientific terms used in this specification have the same meanings as those commonly understood by those skilled in the art to which this application belongs. The terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" as used in this specification includes any and all combinations of one or more of the relevant listed items.
[0034] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.
[0035] In the description and drawings of this application, the directions are agreed upon as follows:
[0036] In the present application, it is defined that the Z axis identifies the axial distance of the light beam, the X axis identifies the radial direction of the light beam, and r identifies the radial direction of the optical waveguide to illustrate the present application.
[0037] Make an agreement on the distribution function: define the distribution function is α distribution, the distribution function n(r)=nR+(n0-nR)(cos(β·r / R)+(-cos(β) / sin(β))sin(β·r / R)) is β Distribution, explain this application.
[0038] This application proposes an optical element that integrates collimation, focusing and shaping, such as Figure 3 As shown, it includes an optical waveguide 5, and the refractive index distribution of the optical waveguide 5 is configured to decrease radially from the inside to the outside; in some embodiments of the present application, the optical element proposed in the present application is presented in the form of a gradient refractive index lens, and the optical waveguide 5 is the refractive index gradient part of the gradient refractive index lens; in other embodiments of the present application, the optical element proposed in the present application is presented in the form of a gradient refractive index optical fiber, and the optical waveguide 5 is the core of the gradient refractive index optical fiber.
[0039] The outer side surface of the optical waveguide 5 is configured as an outer edge 8 of the optical element.
[0040] The two bottom surfaces of the optical waveguide 5 proposed in this application are respectively configured as a light receiving surface 9 and a light output surface 10. The light receiving surface 9 is perpendicular to or has a specific angle with the outer surface; the light output surface 10 is perpendicular to or has a specific angle with the outer surface.
[0041] In some embodiments of the present application, the outer side of the optical waveguide is a circular outer side, and the refractive index distribution of the optical waveguide is configured to be constant in the axial direction; circularly symmetrically distributed in the radial plane; and gradually decrease from the center to the circumference in the radial direction.
[0042] The optical element proposed in this application is configured to collimate, focus and shape the original light beam 6 to form a shaped light beam 7 with a long focal depth; the original light beam 6 of this application is not only collimated and focused, but also shaped to form a shaped light beam with a long focal depth.
[0043] Background Art A graded-index fiber / lens with an α profile (α=2) has been introduced and obtained as Figure 2 The beam shown in B. α = 1.7 can achieve a certain optimization result. As a comparative example, its beam shaping effect is as follows Figure 5 A means, Figure 5 The curve in the vertical axis represents the axial intensity distribution of the light beam; the color image represents the intensity distribution of the light beam, such as Figure 5As shown in the color bar on the right, the corresponding colors from bottom to top represent the light intensity from weak to strong. It can be seen that when α=1.7, the optical element with α distribution has a certain effect of extending the focal depth of the light beam compared with the optical element with α=2, but its radial extension effect of the light beam cannot meet the focal depth length required for laser processing and the uniform light energy distribution within the Rayleigh range. In the embodiment of the present application, the refractive index distribution of the optical waveguide 5 is configured to satisfy the distribution function n(r)=nR+(n0-nR)(cos(β·r / R)+(-cos(β) / sin(β))sin(β·r / R))(hereinafter referred to as β distribution). In this distribution function, n0 is the refractive index at the center of the optical waveguide, nR is the refractive index of the outer edge, R is the radius of the circle enclosed by the outer edge, β is the gradient constant, and the value range of β is 1<β<1.95. Under this distribution condition, the value range of the numerical aperture of the optical element is like Figure 5 As shown in B, the shaped light beam output by the optical element that satisfies the distribution function provided by the present application has a more uniform Z-axis light intensity distribution, and the focal depth (Rayleigh range) is significantly greater than Figure 5 The focal depth (Rayleigh range) length in A can balance the axial light intensity distribution, improve processing efficiency and effect, avoid processing defects such as cutting slag and welding pores, and obtain better processing results.
[0044] In some preferred embodiments of the present application, the original light beam 6 is transmitted by an optical fiber, and the optical element receives the original light beam 6 transmitted by the optical fiber by direct coupling with the optical fiber, coupling with an optical glue process, and / or fusion coupling. It is understood that the original light beam 6 can also be transmitted in the form of spatial light, which is not a limitation of the present application. In particular, the optical element provided in the present application is fused with the optical fiber transmitting the original light beam 6 to collimate, focus, and shape the original light beam 6, further improving the reliability of the optical system and making the fusion operation simple and convenient.
[0045] The optical element of the collimating, focusing and shaping integration has a pitch, and the pitch of the optical waveguide is P = 2π·R·n0 / NA. Figure 6 As shown, when the light beam travels through one cycle in the optical element, the axial length it travels is the pitch of the optical element. It can be seen that when the axial length of the light beam traveling in the optical element is between 0.25P and 0.5P, or between 0.75P and P, the optical element focuses the light beam. In some embodiments of the present application, the length L of the optical waveguide provided by the present application is (0.25+n / 2)P<L<(0.5+m / 2)P, where n is a positive integer or n=0, m is a positive integer or m=0, and m≥n.
[0046] Optionally, in some embodiments of the present application, the light receiving surface of the optical element is a flat surface or a curved surface; and the light output surface of the optical element is a flat surface or a curved surface. In some preferred embodiments of the present application, the light output surface of the optical element proposed in the present application is configured as a curved surface. The curved light output surface can provide a better focusing effect, compensate for the dispersion of the shaped light beam, and obtain a shaped light beam more suitable for laser processing operations.
[0047] Optionally, the optical waveguide may have a cylindrical or tapered shape. In some embodiments of the present application, the optical waveguide included in the optical element may be a cylindrical optical waveguide, and the refractive index distribution of its cross-section 12 satisfies the aforementioned β distribution. Of course, the optical waveguide 5 proposed in the present application may also be a tapered optical waveguide, and the refractive index distribution of its cross-section 12 also satisfies the aforementioned β distribution.
[0048] It can be understood that, in some embodiments of the present application, the surface of the light receiving surface is coated with an anti-reflection film and / or an anti-reflection film, and the light output surface is coated with an anti-reflection film and / or an anti-reflection film. In some preferred embodiments of the present application, the film layer of the anti-reflection film coated on the light receiving surface may be a special coating that matches the refractive index of the optical waveguide; in some preferred embodiments of the present application, the film layer of the anti-reflection film coated on the light receiving surface may be a special coating that matches the refractive index of the optical waveguide. In some preferred embodiments of the present application, the film layer of the anti-reflection film coated on the light output surface may be a special coating that matches the refractive index of the optical waveguide. In some preferred embodiments of the present application, the film layer of the anti-reflection film coated on the light output surface may be a special coating that matches the refractive index of the optical waveguide; in some preferred embodiments of the present application, the film layer of the anti-reflection film coated on the light output surface may be a special coating that matches the refractive index of the optical waveguide. Applying a specialized coating on the light receiving and light output surfaces that matches the refractive index of the optical waveguide can further improve the transmittance of the light receiving and / or light output surfaces, reducing the generation of reflected light and stray light. Of course, conventional anti-reflection and / or anti-reflection coatings, or solutions without coatings, are also naturally within the scope of this application.
[0049] Optionally, in some embodiments of the present application, a cross section 12 is made on the optical waveguide, and the optical element proposed in the present application further includes: Figure 4 The protective layer 11 shown here seamlessly surrounds the outer surface of the optical waveguide. The protective layer can protect the optical waveguide 5 within the optical element, provide a better optical environment for the optical waveguide 5, or cooperate with the optical waveguide 5 to better collimate, focus, and shape the light beam. It is understood that when the optical element proposed in this application is used to collimate, focus, and shape the original light beam 6, a portion of the light beam transmitted within the optical element will reside within the protective layer, which is naturally encompassed by this application.
[0050] In some embodiments of the present application, the optical element proposed in the present application is presented in the form of a gradient refractive index lens, and the protective layer is a protective structure for the outer surface of the gradient refractive index lens; in other embodiments of the present application, the optical element proposed in the present application is presented in the form of a gradient refractive index optical fiber, and the optical waveguide is a protective structure such as the cladding and coating layer of the gradient refractive index optical fiber.
[0051] The present application also provides a laser, comprising the optical element as described above, and also comprising a laser generating device, wherein the beam output end of the laser generating device is coupled or fusion-coupled with the beam input end of the first optical fiber through spatial optical coupling or optical glue process; the laser generating device is configured as a light source for generating an original light beam; the original light beam output by the laser generating device enters the optical element provided in the present application after being transmitted through the first optical fiber, and outputs a shaped light beam with a long focal depth, and the shaped light beam is configured as the output beam of the laser.
[0052] The present application also provides a laser processing device, including the laser as described above, and the laser processing device is used to apply the output long focal depth shaped light beam to the laser processing material. It is understandable that laser processing may cause splashing. Before the light beam output by the optical element proposed in the present application acts on the laser processing material, there is at least one light-transmitting lens between the processing material and the optical element proposed in the present application to protect the optical system. This is a conventional setting in the industry and is naturally included in the present application. The optical element proposed in the present application is installed at the light output end of the laser processing device, and can output a shaped light beam that has been collimated, focused, and shaped by the optical element provided in the present application to balance the axial light intensity distribution, improve processing efficiency and effect, and reduce the possibility of processing defects such as cutting slag and welding pores.
[0053] Compared with the prior art, this application has at least the following beneficial technical effects:
[0054] The present application provides an integrated collimating, focusing, and shaping optical element. This element uses a single optical element to replace the end caps, focusing lenses, angular conical lenses, and collimating lenses of the prior art to collimate, focus, and shape the original light beam, thereby outputting a shaped light beam. The integrated collimating, focusing, and shaping optical element provided by the present application simplifies the optical path structure, reduces space usage, and addresses the difficulties and high costs associated with preparing spatial optical shaping elements such as angular conical lenses; the optical shaping assembly consisting of collimating lenses, angular conical lenses, and focusing lenses requires a larger optical shaping space; and the structural reliability of outputting a shaped light beam using a spatial optical path is poor, and the spatial optical coupling operation is complex, resulting in a high level of stray light.
[0055] The collimating, focusing, and shaping integrated optical element provided by the present application can achieve uniform axial light intensity distribution of the shaped light beam within the Rayleigh range while extending the focal depth of the shaped light beam, thereby obtaining better light energy utilization and processing effect; the original light beam includes a spatial light beam or a light beam transmitted by an optical fiber. The collimating, focusing, and shaping integrated optical element provided by the present application can be fixed together with the optical fiber that transmits the light beam by welding or optical glue process connection, further improving the reliability of the optical system. The welding operation can be achieved using an existing welding machine, and the optical coupling is simple and convenient. In particular, the light beam transmitted by the optical fiber can be directly received and output by the optical element proposed by the present application that is welded to the optical fiber, and the shaped light beam can be directly output in the subsequent optical path to participate in the laser processing operation.
[0056] The radial refractive index distribution of the integrated collimating, focusing, and shaping optical element provided by the present application is different from the refractive index distribution of the gradient refractive index lens with a square index distribution in the prior art. The refractive index distribution of the optical element can be specifically designed according to different processing requirements; it can achieve collimation, focusing, and shaping of the original light beam, and the Rayleigh range of the output shaped light beam is greatly extended. Within the Rayleigh range, the light intensity distribution of the light beam is uniform. In some preferred embodiments of the present application, the light output surface of the optical element proposed by the present application is configured as a curved surface. The curved light output surface can provide a better focusing effect and can achieve dispersion compensation of the light beam, thereby obtaining a shaped light beam that is more suitable for laser processing operations. Providing a special coating on the light receiving surface and the light output surface that matches the refractive index of the optical waveguide can further improve the light transmittance of the light receiving surface and / or the light output surface, and reduce the formation of return light and stray light.
[0057] The present application also proposes a laser that uses the optical elements provided in the present application to directly output a spatially distributed shaped light beam. The laser output head has a simple structure, good airtightness, and is easy to maintain.
[0058] This application also proposes a laser processing device. Using the optical elements and laser provided in this application, the laser processing device proposed in this application has a simple processing output head and has obvious advantages in laser processing situations where the focus position has a limited adjustable range.
[0059] In summary, the present application provides an optical element, laser, and laser processing device with integrated collimation, focusing, and shaping, which solves the technical problem in the prior art that the optical shaping components required for beam shaping the original light beam output by the optical fiber and outputting the shaped light beam are complex and difficult to prepare. A single optical element is used to replace the end cap, focusing mirror, conical mirror, and collimating mirror of the prior art to collimate, focus, and shape the original light beam and output the shaped light beam. The optical element, laser, and laser processing device with integrated collimation, focusing, and shaping provided by the present application have a simple optical path structure, meet the requirements of laser processing, are conducive to the miniaturization of the laser output head, reduce the production cost of the laser, and improve the reliability of the laser processing system. Therefore, the present application effectively overcomes the various shortcomings of the prior art and has a high industrial utilization value.
[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Based on the concept of the present application, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the present application as described above. For the sake of simplicity, they are not provided in detail. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.
Claims
1. An optical element integrating collimation, focusing and shaping, characterized in that: Comprising: An optical waveguide, the refractive index distribution of the optical waveguide being configured to gradually decrease radially from the inside outwards; The outer side surface of the optical waveguide is configured as the outer edge of the optical element; The two bottom surfaces of the optical waveguide are respectively configured as a light receiving surface and a light output surface, the light receiving surface is perpendicular or at a specific angle to the outer side surface, and the light output surface is perpendicular or at a specific angle to the outer side surface; The optical element is configured to collimate, focus, and shape an original light beam to form a shaped light beam with a long depth of focus.
2. The optical element according to claim 1, wherein The refractive index distribution is configured to satisfy the distribution function n(r)=n R +(n0-n R )(cos(β·r / R)+(-cos(β) / sin(β))sin(β·r / R)); where, n R is the refractive index of the outer edge, n0 is the refractive index at the center of the optical waveguide, r is the distance from any point A in the optical waveguide to the center of the optical waveguide, R is the distance from the outer edge to the center, and n(r) is the refractive index at the position of the point A; β is the gradient refractive index constant, and the value range of β is 1<β<1.95; the value range of the numerical aperture NA of the optical element is 3. The optical element according to claim 1, wherein The axial light intensity distribution of the shaped light beam is uniform within the Rayleigh range.
4. The optical element according to claim 1, wherein The original light beam is transmitted by an optical fiber, and the connection manner between the optical element and the optical fiber includes direct coupling, optical adhesive process coupling, or fusion splicing coupling; or, the original light beam is transmitted in the form of spatial light.
5. The optical element according to claim 2, wherein The pitch P of the optical waveguide = 2π·R·n0 / NA; the value range of the length L of the optical waveguide is (0.25 + n / 2)P < L < (0.5 + m / 2)P, where n is a positive integer or n = 0, m is a positive integer or m = 0, and m ≥ n.
6. The optical element according to claim 1, wherein The optical waveguide includes a columnar shape and a conical shape.
7. The optical element according to claim 1, wherein The light receiving surface is a plane or a curved surface; the light output surface is a plane or a curved surface; an antireflection film and / or a reflection-reducing film is coated on the surface of the light receiving surface, and an antireflection film and / or a reflection-reducing film is coated on the light output surface.
8. The optical element according to claim 1, wherein It further includes a protective layer, the protective layer surrounds the outer side surface of the optical waveguide without a gap, and the refractive index distribution of the protective layer is represented by one or more segments of one or more functions with the outer edge as the boundary condition.
9. A laser, comprising the optical element as described in any one of claims 1-8, and further comprising a laser generating device, the beam output end of the laser generating device outputs the original light beam; the laser generating device is configured as a light source for generating the original light beam; the shaped light beam is configured as the output light beam of the laser.
10. A laser processing device, comprising the laser as described in claim 9, and the laser processing device is used to apply the output light beam to a laser processing material.