Hollow laser processing optical system based on integrated ring reflector

Abstract

The invention discloses a hollow laser processing optical system based on an integrated ring-forming reflector, and belongs to the technical field of laser processing. The system comprises a collimating lens, a first plane mirror, an integrated ring forming mirror, a ridge beam splitter, a second plane mirror, a ridge beam combiner and a focusing lens which are sequentially arranged in the direction of a laser light path, the collimating lens collimates the laser beam; the first plane mirror is of a hollow structure, penetrates through a downward circular light beam and reflects an upward annular light beam. The integrated ring-forming reflector shapes the circular light beam into an annular light beam; the ridge beam splitter divides the annular light beam into two semi-annular light beams; the second plane mirror deflects the light beam by 90 degrees; and the ridge beam combiner combines the two semi-annular light beams into an annular light beam, and the annular light beam is focused by the focusing lens to process the material. The problems that a traditional conical reflecting mirror is prone to shielding and difficult to align are solved, the light intensity of generated annular light is concentrated on an outer ring, and the requirements of coaxial wire feeding laser machining and laser-arc coaxial machining can be met.

Description

Technical Field

[0001] This invention belongs to the field of laser processing technology, and more specifically, relates to a hollow laser processing optical system with an integrated ring-shaped reflector. Background Technology

[0002] With the development of advanced laser manufacturing technology, the demands for processing precision, efficiency and adaptability in fields such as automobiles, electronics, aerospace, and machinery manufacturing are constantly increasing, driving the development of laser processing systems towards multi-functionality and high compatibility.

[0003] Among them, coaxial wire-feeding laser processing technology refers to using beam splitting technology to centrally and vertically feed the wire to the processing surface, ensuring that the laser beam is coaxial with the center line of the wire. It has good wire feeding directionality, uniform material heating, and strong laser-material coupling, which can significantly improve the quality of additive manufacturing and surface cladding. On the other hand, coaxial laser-arc hybrid welding technology, through the synergistic effect of laser and arc, combines the advantages of concentrated laser energy and wide arc cladding range to effectively solve the problems of insufficient penetration and difficulty in controlling the heat-affected zone in thick plate welding and high thermal conductivity material processing by single laser welding. At the same time, it makes up for the defects of large deformation and low precision of single arc welding, and is urgently needed in fields such as heavy machinery and pipeline welding.

[0004] Existing coaxial machining optical systems suffer from limited functionality and poor compatibility: traditional coaxial wire-feeding laser machining systems are only compatible with wire materials and cannot be used with arc welding torches; while dedicated laser-arc hybrid systems often employ split-mirror structures, which are prone to beam obstruction and alignment difficulties. Among commonly used ring light generation methods, conical mirrors are complex to install and easily obstruct the beam, causing energy loss. The resulting ring light exhibits an inner ring energy higher than the outer ring, which is detrimental to machining; while axonal pyramids are limited by lens characteristics, making it difficult to withstand high-power lasers and adapting to the installation requirements of arc welding torches.

[0005] Therefore, existing technologies suffer from drawbacks such as limited functionality, susceptibility to shading, and poor energy distribution. Summary of the Invention

[0006] In view of the shortcomings of related technologies, the purpose of this invention is to provide a hollow laser processing optical system based on an integrated ring-shaped reflector, which aims to solve the problems of single function, easy obstruction and poor energy distribution in the existing technology.

[0007] To achieve the above objectives, the present invention provides a hollow laser processing optical system based on an integrated ring mirror, comprising: a collimating lens, a first plane mirror, an integrated ring mirror, a roof beam splitter, a second plane mirror, a roof beam combiner, and a focusing lens, which are arranged sequentially along the laser beam path. The collimating lens is used to collimate the diverging laser beam output by the laser to form a parallel circular beam. The integrated ring-shaped reflector includes a central portion, an outer portion, and a transition groove. The central portion is a conical surface facing the laser incident direction, used to reflect the incident parallel circular beam of light radially to the outer portion. The outer portion is higher than the central portion, and the outer portion is a conical surface facing the opposite direction to the central portion, used to deflect the beam of light reflected by the central portion to form a parallel ring beam for emission. The transition groove is disposed between the central portion and the outer portion. The first planar reflector is a hollow reflector, the diameter of its central hole is larger than the diameter of the parallel circular beam, but smaller than the inner ring diameter of the annular beam output by the integrated ring reflector; the first planar reflector is used to transmit the circular beam transmitted from top to bottom and reflect the annular beam transmitted from bottom to top, thereby adjusting the direction of the optical path. The ridge beam splitter is used to split the annular beam into two semi-annular beams so that the wire feeder or arc welding torch can pass through the two semi-annular beams. The second plane mirror is a hollow mirror, the diameter of its central hole is larger than the diameter of the wire or the diameter of the arc welding gun head, and smaller than the inner ring diameter of the annular beam, so that the wire or the arc welding gun can pass through; the second plane mirror is used to deflect the semi-annular beam by 90 degrees and adjust the direction of the light path. The ridge beam combiner is used to re-bend the two deflected semi-circular beams into a complete circular beam. The focusing lens is used to focus the combined ring beam to form a ring-shaped light spot output.

[0008] Optionally, the energy density of the central region of the circular beam output by the collimating lens is greater than the energy density of the peripheral region; The cone apex of the central part of the integrated ring-forming mirror is located in the center position, which is used to reflect the central region of the circular beam to the outer region of the cone surface of the outer part of the integrated ring-forming mirror, and to reflect the outer region of the circular beam to the inner region of the cone surface of the outer part of the integrated ring-forming mirror. The outer diameter energy density of the ring beam output by the integrated ring-shaped reflector is greater than the inner diameter energy density.

[0009] Optionally, the width of the transition groove of the integrated ring-forming mirror is adjustable, and adjusting the width of the transition groove of the integrated ring-forming mirror changes the radius of the ring beam.

[0010] Optionally, the reflective surfaces of the first plane mirror, the integrated ring mirror, and the second plane mirror are all coated with a high-reflectivity film.

[0011] Optionally, the collimating lens, the roof beam splitter, the roof beam combiner, and the focusing lens are all coated with a high-transmission film on their refractive surfaces.

[0012] Optionally, the first planar reflector may be made of copper, aluminum, or glass.

[0013] Optionally, both the ridge beam-combining mirror and the focusing lens contain hollow holes and are coaxial with the central hole of the second plane mirror.

[0014] Optionally, the ridge beam combiner and the ridge beam splitter are structurally matched and are both ridge lenses.

[0015] Compared with the prior art, the above-described technical solutions conceived in this invention can achieve the following beneficial effects: 1. This invention provides a hollow laser processing optical system based on an integrated ring-forming mirror. By using conical surfaces with opposite orientations at the center and periphery of the integrated ring-forming mirror, the incident beam is refracted and returns along a preset optical path, generating an unobstructed, complete ring beam. This solves the problems of difficult installation and easy obstruction associated with conical mirrors. It also solves the problem of difficult alignment between multiple mirrors in split ring-forming mirrors, making optical path adjustment simpler in practical use. The integrated ring-forming mirror optimizes the energy distribution of the ring beam, resulting in a higher energy density near the outer ring than near the inner ring, achieving better beam quality and energy distribution.

[0016] 2. This invention provides a hollow laser processing optical system based on an integrated ring-shaped reflector. A central hole is set in the central part of the first plane reflector, the second plane reflector, the roof beam combiner and the focusing lens. Through a universal hollow structure design, it can be adapted to wire and arc welding gun. At the same time, the ring light energy distribution is optimized, and it is compatible with both coaxial wire feeding laser processing and laser-arc composite processing, thus realizing a more universal coaxial laser processing solution. Attached Figure Description

[0017] Figure 1 A schematic diagram of a hollow laser processing optical system based on an integrated ring-shaped reflector provided in an embodiment of the present invention; Figure 2 A schematic diagram of light spots at various points in the optical structure of a hollow laser processing optical system based on an integrated ring-shaped reflector, provided for an embodiment of the present invention; Figure 3 A schematic diagram of the first planar mirror in a hollow laser processing optical system based on an integrated ring mirror, provided for an embodiment of the present invention; Figure 4 A schematic diagram of the surface profile of an integrated ring-shaped mirror in a hollow laser processing optical system based on an integrated ring-shaped mirror, provided for an embodiment of the present invention; Figure 5A schematic diagram illustrating the light reflection principle of an integrated ring-shaped mirror in a hollow laser processing optical system based on an integrated ring-shaped mirror, provided as an embodiment of the present invention. Figure 6 A schematic diagram of a roof beam splitter in a hollow laser processing optical system based on an integrated ring mirror, provided for an embodiment of the present invention; Figure 7 A schematic diagram of a second planar reflector in a hollow laser processing optical system based on an integrated ring reflector, provided for an embodiment of the present invention; Figure 8 This is a schematic diagram of a roof beam combiner in a hollow laser processing optical system based on an integrated ring-forming mirror, provided as an embodiment of the present invention.

[0018] The attached diagram lists the components represented by each number as follows: 1. Collimating lens, 2. First plane mirror, 3. Integrated ring mirror, 4. Ridge beam splitter, 5. Second plane mirror, 6. Ridge beam combiner, 7. Focusing lens, 8. Wire feeder or arc welding torch. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0020] The following description, in conjunction with a preferred embodiment, illustrates the content involved in the above embodiments.

[0021] To address the technical problems existing in the prior art, this invention proposes a hollow laser processing optical system based on an integrated ring-shaped reflector. Through a universal hollow structure design, it adapts to both wire and arc welding torch, while optimizing the ring light energy distribution. This system meets the requirements of both processing methods and realizes an optical system compatible with coaxial wire feeding laser processing and coaxial laser-arc hybrid welding.

[0022] like Figure 1 As shown, the present invention provides a hollow laser processing optical system based on an integrated ring mirror, comprising: a collimating lens 1, a first plane mirror 2, an integrated ring mirror 3, a roof beam splitter 4, a second plane mirror 5, a roof beam combiner 6, and a focusing lens 7, which are arranged sequentially along the laser beam path. The collimating lens 1 is used to collimate the diverging laser beam output by the laser to form a parallel circular beam. The integrated ring-shaped reflector 3 includes a central portion 31, an outer portion 32, and a transition groove 33. The central portion 31 is a conical surface facing the laser incident direction, used to reflect the incident parallel circular beam of light radially to the outer portion. The outer portion 32 is higher than the central portion, and the outer portion 32 is a conical surface facing the opposite direction to the central portion, used to deflect the beam of light reflected by the central portion 31 to form a parallel ring beam for emission. The transition groove 33 is disposed between the central portion 31 and the outer portion 32. The first planar reflector 2 is a hollow reflector, the diameter of its central hole is larger than the diameter of the parallel circular beam, but smaller than the inner ring diameter of the annular beam output by the integrated ring reflector 3; the first planar reflector 2 is used to transmit the circular beam transmitted from top to bottom and reflect the annular beam transmitted from bottom to top, thereby adjusting the direction of the optical path. The ridge beam splitter 4 is used to split the annular beam into two semi-annular beams so that the wire feeder or arc welding gun can pass through the two semi-annular beams. The second plane mirror 5 is a hollow mirror, the diameter of its central hole is larger than the diameter of the wire or the diameter of the arc welding gun head, and smaller than the inner ring diameter of the annular beam, so that the wire or the arc welding gun can pass through; the second plane mirror is used to deflect the semi-annular beam by 90 degrees and adjust the direction of the light path. The ridge beam-combining mirror 6 is used to re-combine the two deflected semi-circular beams into a complete circular beam. The focusing lens 7 is used to focus the combined annular beam to form an annular light spot output.

[0023] The collimating lens 1 collimates the parallel circular beam, providing stable incident conditions for subsequent beam shaping. The ridge beam splitter 4 splits the annular beam into two semi-annular beams, preventing the beam from being pre-blocked by the wire or arc welding gun during propagation.

[0024] like Figure 2 The diagram shows the light spots at various points in the optical structure of the hollow laser processing optical system based on an integrated ring-forming mirror provided in this embodiment of the invention. The laser outputs a laser beam, which is collimated by the collimating lens 1. The collimated beam passes through the hole in the middle of the first plane mirror 2, and after being reflected twice by the integrated ring-forming mirror 3, it forms a ring beam and is deflected by 180 degrees. It is then reflected and deflected by 90 degrees at the first plane mirror 2. The ring beam is split into two semi-ring beams by the roof beam splitter 4 and propagates. After propagating to the second plane mirror 5, the beam is deflected by 90 degrees again. Then, the beam passes through the roof beam combiner 6, and the two semi-ring beams are re-combined into a hollow ring beam. Finally, the diverging ring beam is focused by the focusing lens 7 and then processed in conjunction with the wire feeding device or the arc welding torch 8.

[0025] Among them, such as Figure 3 As shown, the first plane mirror 2 is a hollow mirror, wherein the size of the central hole of the first plane mirror 2 must be greater than the radius of the circular beam incident from the direction of the collimating lens 1, and smaller than the inner diameter of the annular beam incident from the direction of the integrated ring mirror 3.

[0026] Optionally, the energy density of the central region of the circular beam output by the collimating lens 1 is greater than the energy density of the outer region; The cone apex of the conical surface of the central portion 31 of the integrated ring-forming mirror 3 is located in the center position, which is used to reflect the central region of the circular beam to the outer region of the conical surface of the peripheral portion 32 of the integrated ring-forming mirror 3, and to reflect the peripheral region of the circular beam to the inner region of the conical surface of the peripheral portion 32 of the integrated ring-forming mirror 3. The outer diameter energy density of the ring beam output by the integrated ring-shaped reflector 3 is greater than the inner diameter energy density.

[0027] like Figure 4 and Figure 5 As shown, the integrated ring-shaped reflector 3 comprises three parts: a central part 31 with a conical surface facing the laser incident direction, and an outer part 32 with a conical surface corresponding to the central part 31 but facing the opposite direction. The circular beam of light propagating vertically downwards is reflected by the conical surface of the central part 31 and then propagates radially outwards along the conical surface. After passing through the transition groove 33, it is reflected again at the conical surface of the outer part 32 to form a parallel ring beam that propagates vertically upwards. The width of the transition groove 33 is adjustable, and adjusting the width of the transition groove 33 changes the radius of the ring beam.

[0028] Reference Figure 5 Because the portion of the incident circular beam with higher energy density near the center is reflected by the conical surface (central cone) of the central portion 31 to the outer part of the outer cone; and the portion of the incident circular beam with lower energy density near the edge is reflected by the conical surface (central cone) of the central portion 31 to the inner part of the outer cone, the final emitted ring beam has a distribution state with higher energy density on the outer diameter and lower energy density on the inner diameter.

[0029] like Figure 6 The diagram shown is of the ridge beam splitter 4. Figure 8 The diagram shows a ridge beam combiner 6. Both the ridge beam splitter 4 and the ridge beam combiner 6 are standard ridge lenses. The translation of the outgoing light is changed by adjusting the angle and thickness of the ridge beam splitter 4 / ridge beam combiner 6. In this embodiment of the invention, the angle and thickness of the ridge beam combiner 6 are matched with those of the ridge beam splitter 4.

[0030] Furthermore, such as Figure 7 As shown, the second plane mirror 5 is a hollow mirror.

[0031] The second plane mirror 5, the ridge beam combiner 6, and the focusing lens 7 all contain hollow holes, and each hollow hole is coaxial, which facilitates the placement of the wire feeding device; the diverging hollow annular light spot is focused by the focusing lens and then processed with the coaxially fed wire.

[0032] Optionally, the reflective surfaces of the first plane mirror, the integrated ring mirror, and the second plane mirror are all coated with a high-reflectivity film.

[0033] Optionally, the collimating lens, the roof beam splitter, the roof beam combiner, and the focusing lens are all coated with a high-transmission film on their refractive surfaces.

[0034] Further improve reflectivity and transmittance, and reduce light loss.

[0035] Optionally, the first planar reflector may be made of copper, aluminum, or glass.

[0036] Aluminum, as a reflective material, covers a wide wavelength range from ultraviolet to mid-infrared and has high reflectivity. Its surface can form a dense oxide film that resists oxidation, and it also boasts advantages such as lightweight, good processability for mass production, and low cost. Copper exhibits excellent reflectivity from far-infrared to millimeter-wave bands, possesses ultra-high thermal conductivity for rapid heat dissipation to address high-power thermal distortion, and can be polished to an atomically smooth mirror surface. Glass, as a substrate for reflective mirror coatings, achieves ultra-high surface precision, and its extremely low coefficient of thermal expansion and excellent chemical and environmental stability provide a superior adhesion base for coatings.

[0037] The solution of this invention can realize two processing methods, coaxial wire feeding laser processing and coaxial laser-arc composite processing, through a universal hollow channel and a switchable processing carrier.

[0038] In coaxial wire-feed laser processing, the wire feeding mechanism delivers the wire to the surface of the workpiece through a hollow channel serving as the installation path. This invention provides a hollow laser processing optical system based on an integrated ring-shaped reflector. The ring laser generated interacts with the surface of the workpiece to form a molten pool. The wire melts under the heat conduction of the molten pool and direct irradiation by a small amount of laser light. Combined with the corresponding wire delivery rate and the moving speed of the laser processing device, laser processing methods such as laser welding or metal additive manufacturing are achieved. The coaxial arrangement of the laser and wire in this embodiment makes the forming process completely non-directional, avoiding the drawbacks of frequent adjustments to the equipment posture required for complex paths in traditional off-axis wire feeding processing. By using an integrated ring-shaped reflector, the problems of difficult installation and easy obstruction of traditional split conical reflectors are solved, enabling the generation of an unobstructed, complete ring beam.

[0039] In the coaxial laser-arc hybrid processing mode, the arc welding torch achieves coaxial coupling with the laser through a hollow hole serving as an installation channel, forming a completely non-directional composite heat source. This composite heat source combines the advantages of both laser and arc processing, achieving processing results exceeding those of a single heat source. The ring-shaped laser generated by this solution avoids damage to the welding torch, laser head, and other equipment caused by the central beam in traditional coaxial hybrid processing; the ring-shaped spot achieves uniform laser energy distribution in all directions, completely solving the directional limitations of off-axis hybrid processing and significantly simplifying processing equipment and path planning; simultaneously, the ring-shaped spot enhances the constraint and compression effect on the arc, making the arc heat more concentrated and the rigidity higher, comprehensively improving manufacturing efficiency and product forming quality.

[0040] Compared to existing coaxial wire-feeding laser processing solutions with ring beams, the solution of this invention solves the problems of difficult installation and easy obstruction of the conical reflector during ring beam generation. The hollow hole design allows this solution to simultaneously support both coaxial wire-feeding laser processing and laser-arc hybrid processing, achieving a more universal coaxial laser processing solution. Furthermore, it optimizes the energy distribution of the ring beam, forming an energy distribution with a higher energy density near the outer ring than near the inner ring. This results in a hollow laser processing optical system based on an integrated ring reflector, offering better stability and beam quality, and can be widely used in laser applications such as additive manufacturing, surface cladding, and welding.

[0041] In one specific embodiment, a fiber laser with a numerical aperture (NA) of 0.15 is selected as the laser source, and an aspherical collimating lens 1 with a focal length of 100mm is selected as the collimating lens 1. The laser emitted by the fiber laser is collimated by the collimating lens 1 to obtain a circular parallel beam with a diameter of 30mm. The first plane mirror 2 is a circular plane mirror with a diameter of 92mm, wherein the aperture is an ellipse with a minor axis of 42mm and a major axis of 54.9mm; wherein the major axis direction is the same as the deflection direction of the beam in the first plane mirror 2, which is used to ensure that the beam after collimating lens 1 can pass downward through the first plane mirror. The diameter of the bottom surface of the central cone of the integrated ring mirror 3 is 34mm, and the bottom angle of the central cone is 45 degrees; the width of the transition groove is 4mm, the depth is 2mm, and the diameter of the bottom surface of the outer cone is 80mm, with a bottom angle of 45 degrees. The cylindrical light passing downwards through the central hole of the first plane mirror 2 is reflected twice at the integrated ring mirror 3 by the central and outer conical surfaces, forming an annular spot with an inner diameter of 46mm and an outer diameter of 76mm. This spot is then deflected 90 degrees by the first plane mirror 2. The two refracting surfaces of the roof beam splitter 4 have an included angle of 90 degrees and a thickness of 27.20°, splitting the annular beam into two semi-annular beams spaced 12mm apart, compatible with wire feeders or arc welding torches 8 with diameters less than 12mm. The second plane mirror 5 is a circular plane mirror with a diameter of 92mm. Its opening is an ellipse with a minor axis of 42mm and a major axis of 54.9mm, with the major axis pointing in the same direction as the deflection of the beam in the second plane mirror 5, ensuring that the wire feeder or arc welding torch 8 can pass through. The two refractive surfaces of the ridge beam combiner 6 have an included angle of 90 degrees and a thickness of 27.20 mm. It combines two semi-annular beams spaced 12 mm apart into a single annular beam with a central 42 mm circular aperture to ensure the wire feeder or arc welding torch 8 can pass through. The focusing lens 7 is a 90 mm diameter aspherical focusing lens that focuses the annular beam into a desired annular spot size at the corresponding working distance. Its central 42 mm circular aperture also ensures the wire feeder or arc welding torch 8 can pass through.

[0042] The embodiment provides a hollow laser processing optical system based on an integrated ring-forming mirror, which solves the problem of the conical mirror being difficult to install and easily blocked during the generation of the ring beam. The hollow hole design allows this solution to simultaneously support both coaxial wire-feeding laser processing and laser-arc hybrid processing, achieving a more universal coaxial laser processing solution. Simultaneously, it optimizes the energy distribution of the ring beam, forming an energy distribution with a higher energy density near the outer ring than near the inner ring. This results in a hollow laser processing optical system based on an integrated ring-forming mirror with better stability and beam quality, which can be widely used in laser applications such as additive manufacturing, surface cladding, and welding.

[0043] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A hollow laser machining optical system based on an integrated ring-mirror, characterized by, The application relates to a laser beam shaping device. The device comprises a collimating lens, a first plane mirror, an integrated annular mirror, a roof beam splitter, a second plane mirror, a roof beam combiner and a focusing lens arranged in sequence along the direction of the laser beam path. The collimating lens is used for collimating the divergent laser beam output by a laser to form a parallel circular light beam. The integrated annular mirror comprises a central part, a peripheral part and a transition groove; the central part is a conical surface facing the direction of laser incidence, and is used for reflecting the incident parallel circular light beam to the peripheral part in the radial direction; the peripheral part is higher than the central part, and the peripheral part is a conical surface facing the opposite direction of the central part, and is used for deflecting the light beam reflected by the central part to form a parallel annular light beam; and the transition groove is arranged between the central part and the peripheral part. The first plane mirror is a hollow mirror, the diameter of the central hole of the first plane mirror is larger than the diameter of the parallel circular light beam and smaller than the inner diameter of the annular light beam output by the integrated annular mirror; the first plane mirror is used for transmitting the circular light beam transmitted from top to bottom and reflecting the annular light beam transmitted from bottom to top to adjust the direction of the light path. The roof beam splitter is used for splitting the annular light beam into two half-annular light beams to enable a wire or an arc welding gun to pass through the two half-annular light beams. The second plane mirror is a hollow mirror, the diameter of the central hole of the second plane mirror is larger than the diameter of the wire or the head of the arc welding gun and smaller than the inner diameter of the annular light beam, so that the wire or the arc welding gun can pass through; the second plane mirror is used for deflecting the half-annular light beam by 90 degrees to adjust the direction of the light path. The roof beam combiner is used for recombining the two deflected half-annular light beams into a complete annular light beam. The focusing lens is used for focusing the recombined annular light beam to form an annular light spot output.

2. The hollow laser machining optical system of claim 1, wherein, The energy density of the central area of the circular light beam output by the collimating lens is larger than the energy density of the peripheral area. The tip of the conical surface of the central part of the integrated annular mirror is located at the central position, and is used for reflecting the light beam of the central area of the circular light beam to the outer side area of the conical surface of the peripheral part of the integrated annular mirror and reflecting the light beam of the peripheral area of the circular light beam to the inner side area of the conical surface of the peripheral part of the integrated annular mirror. The energy density of the outer diameter of the annular light beam output by the integrated annular mirror is larger than the energy density of the inner diameter.

3. The hollow laser machining optical system of claim 1, wherein, The width of the transition groove of the integrated annular mirror is adjustable, and adjusting the width of the transition groove of the integrated annular mirror changes the radius of the annular light beam.

4. The hollow laser machining optical system of claim 1, wherein, High reflection films are coated on the reflecting surfaces of the first plane mirror, the integrated annular mirror and the second plane mirror.

5. The hollow laser machining optical system of claim 1, wherein, High transmission films are coated on the refracting surfaces of the collimating lens, the roof beam splitter, the roof beam combiner and the focusing lens.

6. The hollow laser machining optical system of claim 1, wherein, The material of the first plane mirror is copper, aluminum or glass.

7. The hollow laser machining optical system of claim 1, wherein, The roof beam combiner and the focusing lens both comprise hollow holes, and the hollow holes are coaxial with the central hole of the second plane mirror.

8. The hollow laser machining optical system of claim 1, wherein, The roof beam combiner and the roof beam splitter are matched in structure, and both are roof lenses.

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