Side-lobe-eliminating Bessel beam drilling device

Abstract

The invention discloses a sidelobe-eliminating Bessel beam drilling device, and relates to the technical field of optical devices, the sidelobe-eliminating Bessel beam drilling device mainly comprises a light generation device, a beam shaping device and a regulation and control device, the light generation device is used for generating circularly polarized light; the light beam shaping device comprises a binary phase plate diffraction optical element and a Bessel light generating element, the binary phase plate diffraction optical element is used for modulating the phase of the circularly polarized light, the Bessel light generating element is used for converting the modulated circularly polarized light into Bessel light beams, the binary phase plate diffraction optical element can generate two different light beams, and the Bessel light generating element is used for generating the two different light beams. The beam shaping device comprises a first type of Bessel beams and a second type of Bessel beams, the first type of Bessel beams and the second type of Bessel beams can generate side lobe destructive interference and main lobe constructive interference, and the regulation and control device comprises a double telecentric optical system, is arranged at the tail end of the beam shaping device and can regulate and control the drilling depth and the drilling position of the beams. According to the invention, the side lobe ablation damage to the drill hole can be avoided to a great extent.

Description

Technical Field

[0001] The invention relates to the technical field of optical devices, and in particular to a sidelobe-eliminating Bessel beam drilling device. Background Art

[0002] Through Glass Via (TGV) is a technology for making vertical interconnect structures on glass substrates. Traditional Bessel beams are well-known for their non-diffraction and self-healing properties. Their light fields will not be distorted by diffraction effects, and their extremely high aspect ratio makes them widely used in laser TGV drilling. However, in addition to the main lobe, traditional Bessel beams also have side lobe energy. The peak energy intensity of the side lobe is about 16% of the main lobe. When the side lobe intensity reaches a certain level and the action time is long enough or the energy is concentrated enough, ablation will occur. Ablation may cause local loss of material. During the TGV drilling process, if the side lobe intensity is too high, ablation may occur around the hole wall, expanding the aperture or making the hole wall rough, which is not desirable in practical applications.

[0003] Therefore, there is an urgent need for a sidelobe-eliminating Bessel beam drilling device to solve the above technical problems. Summary of the invention

[0004] The object of the present invention is to provide a sidelobe-eliminating Bessel beam drilling device to solve the problems existing in the above-mentioned prior art and to avoid sidelobe ablation damage to drilling to a large extent.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a sidelobe-eliminating Bessel beam drilling device, comprising

[0007] A light generating device, the light generating device is used to generate circularly polarized light;

[0008] A beam shaping device, the beam shaping device comprising a binary phase plate diffractive optical element and a Bessel light generating element, the binary phase plate diffractive optical element is arranged at the end of the light generating device, the Bessel light generating element is arranged at the end of the binary phase plate diffractive optical element, the binary phase plate diffractive optical element is used to modulate the phase of the circularly polarized light, the Bessel light generating element is used to convert the circularly polarized light passing through the binary phase plate diffractive optical element into a Bessel light beam, when the circularly polarized light passes through the 0 phase region of the binary phase plate diffractive optical element and then enters the Bessel light generating element, a first type of Bessel light beam can be generated; when the circularly polarized light passes through the π phase region of the binary phase plate diffractive optical element and then enters the Bessel light generating element, a second type of Bessel light beam can be generated, and the first type of Bessel light beam and the second type of Bessel light beam can have side lobe destructive interference and main lobe constructive interference;

[0009] The regulating device includes a double telecentric optical system and is arranged at the end of the beam shaping device, and can regulate the drilling depth and drilling position of the light beam.

[0010] Preferably, the light generating device comprises a ray device and a polarization adjusting device, one end of the polarization adjusting device is aligned with the ray device, and the other end is aligned with the beam shaping device, the ray device is used to transmit light to the polarization adjusting device, and the polarization adjusting device comprises a quarter wave plate, and the fast axis direction of the quarter wave plate forms an angle of -45° with the polarization direction of the light.

[0011] Preferably, the ray device is a laser, which can generate linear polarized light and direct the linear polarized light into the polarization adjustment device.

[0012] Preferably, the polarization adjustment device further comprises a rotating mounting seat, the quarter wave plate is fixedly arranged on the rotating mounting seat, and the rotating mounting seat can drive the quarter wave plate to rotate.

[0013] Preferably, the quarter wave plate is a polymer true zero-order quarter wave plate, and the polymer true zero-order quarter wave plate comprises a glass substrate layer, a liquid crystal polymer functional film layer and a glass substrate layer which are arranged in sequence.

[0014] Preferably, the Bessel light generating element is a flat axicon diffractive optical element.

[0015] Preferably, the double telecentric optical system comprises a lens and an objective lens which are arranged in sequence, the lens is aligned with the end of the beam shaping device, and the objective lens is aligned with an end of the lens away from the beam shaping device, and the reduction ratio of the double telecentric optical system can be adjusted by changing the focal length of the objective lens and the lens to control the drilling depth and drilling position of the light beam.

[0016] Preferably, the lens is a plano-convex lens made of fused quartz.

[0017] Preferably, the objective lens is a high-power laser objective lens with a magnification of not less than 5 times.

[0018] Preferably, the beam shaping device and the regulating device are both fixedly installed in a metal sleeve.

[0019] Compared with the prior art, the present invention has achieved the following technical effects:

[0020] The light generating device of the present invention is used to generate circularly polarized light. The beam shaping device comprises a binary phase plate diffractive optical element and a Bessel light generating element. The binary phase plate diffractive optical element is arranged at the end of the light generating device. The Bessel light generating element is arranged at the end of the binary phase plate diffractive optical element. The binary phase plate diffractive optical element is used to modulate the phase of the circularly polarized light. The Bessel light generating element is used to convert the circularly polarized light passing through the binary phase plate diffractive optical element into a Bessel light beam. The binary phase plate diffractive optical element is 0, π phase. The circularly polarized light passes through the 0 phase region of the binary phase plate diffractive optical element and then is incident on the Bessel light generating element to generate a first type of Bessel light beam. The circularly polarized light passes through the π phase region of the binary phase plate diffractive optical element and then is incident on the Bessel light generating element to generate a second type of Bessel light beam. The first type of Bessel light beam and the second type of Bessel light beam have side lobe destructive interference and main lobe constructive interference. The control device comprises a double telecentric optical system and is arranged at the end of the beam shaping device. The drilling depth and drilling position of the light beam can be controlled. The binary phase plate diffractive optical element modulates the phase of the incident light by constructing a microstructure pattern with two different phase states (usually 0 and π) on the surface. According to the Huygens-Fresnel principle, light can be regarded as a superposition of waves emitted by many sub-wave sources. When light is irradiated by the binary phase plate and then incident on the Bessel light generating element, the light generated by the sub-wave sources in different phase regions will interfere during the propagation process, thereby changing the intensity distribution and propagation direction of the light. According to the principle of light interference, when the phase of the light in the sidelobe area is modulated to a suitable value, destructive interference can occur between adjacent sidelobes, that is, by designing the microstructure and phase distribution of the binary phase plate, the sidelobes of the light beam can cancel each other out during the propagation process. The binary phase plate diffractive optical element is used in conjunction with a Bessel light generating element. The circularly polarized light passes through the 0 and π phase regions of the binary phase plate diffractive optical element respectively, and then enters the Bessel light generating element to generate a first type of Bessel light beam and a second type of Bessel light beam respectively. The first type of Bessel light beam and the second type of Bessel light beam undergo sidelobe destructive interference and main lobe constructive interference, which can ensure that the intensity of the main lobe of the Bessel light beam is in a high state, and the side lobe energy is coherently destructed, which can basically achieve that the light spot emitted from the beam shaping device is a Bessel light beam with a side lobe energy less than 10%, which can largely avoid side lobe ablation damage to drilling. Moreover, the binary phase plate diffractive optical element has the advantages of high conversion efficiency, low cost and easy manufacturing. The structure of generating a Bessel beam with low sidelobe energy by using a light generating device and a beam shaping device is simple, and the double telecentric optical system can provide precise control means for drilling depth and drilling position. The double telecentric optical system has the characteristics of parallel optical paths. By changing the focal length of the objective lens and the lens, the beam reduction ratio of the double telecentric optical system can be adjusted, thereby achieving high-precision control of the spot position and depth. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a schematic diagram of the structure of the sidelobe-eliminating Bessel beam drilling device in an embodiment of the present invention without a metal sleeve;

[0023] Figure 2 It is a schematic structural diagram of a sidelobe-eliminating Bessel beam drilling device including a metal sleeve in an embodiment of the present invention;

[0024] Figure 3 1 is a light path diagram of a sidelobe-eliminating Bessel beam drilling device in an embodiment of the present invention.

[0025] In the figure: 1-polarization adjustment device; 2-metal sleeve; 3-high power laser objective lens; 4-polymer true zero-order quarter-wave plate; 5-beam shaping device; 51-binary phase plate diffraction optical element; 52-Bessel light generating element; 6-plano-convex lens; 7-rotating mount; 8-double telecentric optical system. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The purpose of the present invention is to provide a sidelobe-eliminating Bessel beam drilling device to solve the problems existing in the prior art and to avoid sidelobe ablation damage to the drilling to a large extent.

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] like Figure 1-Figure 3As shown, the present invention provides a sidelobe-eliminating Bessel beam drilling device, comprising a light generating device, a beam shaping device 5 and a control device, wherein the light generating device is used to generate circularly polarized light; the beam shaping device 5 comprises a binary phase plate diffractive optical element 51 and a Bessel light generating element 52, wherein the binary phase plate diffractive optical element 51 is arranged at the end of the light generating device, and the Bessel light generating element 52 is arranged at the end of the binary phase plate diffractive optical element 51, wherein the binary phase plate diffractive optical element 51 is used to modulate the phase of the circularly polarized light, and the Bessel light generating element 52 is used to The circularly polarized light passing through the binary phase plate diffractive optical element 51 is converted into a Bessel beam. When the circularly polarized light is incident on the binary phase plate diffractive optical element 51 and then incident on the Bessel light generating element 52, the light generated by the sub-wave sources in different phase regions interferes during the propagation process. Destructive interference occurs between adjacent side lobes in the non-diffraction region of the Bessel beam. The main lobe energy is the result of constructive interference, that is, the main lobe will interfere constructively. The control device includes a double telecentric optical system 8, which is arranged at the end of the beam shaping device 5, and can control the drilling depth and drilling position of the light beam. The binary phase plate diffractive optical element 51 modulates the phase of the incident light by constructing a microstructure pattern with two different phase states (usually 0 and π) on the surface. According to the Huygens-Fresnel principle, light can be regarded as a superposition of waves emitted by many sub-wave sources. When the light is irradiated on the binary phase plate and then incident on the Bessel light generating element, the light generated by the sub-wave sources in different phase regions interferes during the propagation process, thereby changing the intensity distribution and propagation direction of the light. According to the interference principle of light, when the phase of the light in the sidelobe region is modulated to a suitable value, destructive interference can occur between adjacent sidelobes, that is, by designing the microstructure and phase distribution of the binary phase plate, the sidelobes of the light beam can cancel each other out during propagation. The binary phase plate diffractive optical element is used in conjunction with the Bessel light generating element. The circularly polarized light passes through the 0 and π phase regions of the binary phase plate diffractive optical element respectively, and then enters the Bessel light generating element to generate the first type of Bessel light beam and the second type of Bessel light beam respectively. The first type of Bessel light beam and the second type of Bessel light beam have sidelobe destructive interference, and the main lobe constructive interference, that is, the main lobe still maintains constructive interference, which can basically achieve that the light spot emitted from the beam shaping device is a Bessel light beam with a sidelobe energy less than 10%, which can largely avoid sidelobe ablation damage to drilling. Moreover, the binary phase plate diffractive optical element has the advantages of high conversion efficiency, low cost and easy manufacturing. The structure of generating a Bessel beam with low sidelobe energy by using a light generating device and a beam shaping device is simple, and the double telecentric optical system can provide precise control means for drilling depth and drilling position. The double telecentric optical system has the characteristics of parallel optical paths. By changing the focal length of the objective lens and the lens, the beam reduction ratio of the double telecentric optical system can be adjusted, thereby achieving high-precision control of the spot position and depth.

[0030] It should be noted that the diffractive optical element of the beam shaping device 5 is made of liquid crystal material. Liquid crystal has large birefringence and high transmittance. The diffractive optical element based on geometric phase can be manufactured by light-controlled orientation. It has high orientation accuracy and simple manufacturing process. The liquid crystal diffractive optical element can achieve continuous phase and high transmittance, and has high diffraction efficiency, low cost and easy manufacturing process, which provides a wider range of application possibilities for shaping. The diffractive optical element of the beam shaping device 5 finally shapes the Gaussian beam into a new type of non-diffraction beam for ultra-short laser material processing, also known as a sidelobe-eliminating Bessel beam. The energy distribution of the sidelobe-eliminating Bessel beam after the beam shaping device 5 retains all the well-known advantages of the Bessel beam, such as self-healing and high optical efficiency. In addition, it can generate a Bessel beam with a sidelobe energy of less than 10% in the non-diffraction area of ​​its light field, reducing the probability of ablation. The shaped sidelobe-eliminating Bessel beam then passes through the double telecentric optical system 8, which modulates the deflection angle of the sidelobe-eliminating Bessel beam to reduce the size of its central main lobe and the diffraction-free transmission distance (i.e., air focal depth), generate a highly focused beam, enhance the peak energy of the beam, and improve the energy conversion efficiency.

[0031] In some embodiments, the light generating device includes a ray device and a polarization adjustment device 1, one end of the polarization adjustment device 1 is aligned with the ray device, and the other end is aligned with the beam shaping device 5, the ray device is used to transmit light to the polarization adjustment device 1, and the polarization adjustment device 1 includes a quarter wave plate, and the fast axis direction of the quarter wave plate is at an angle of -45° with the polarization direction of the light. After the linear polarized light passes through the quarter wave plate, it will be decomposed into ordinary light (o light) and extraordinary light (e light). When the polarization direction of the linear polarized light is 45 degrees to the fast axis direction of the quarter wave plate, the amplitudes of the o light and the e light are equal. After passing through the quarter wave plate, due to the different propagation speeds of the o light and the e light in the wave plate, a certain phase difference will be generated. When this phase difference is one quarter wavelength, the linear polarized light will be converted into circularly polarized light. The fast axis direction of the quarter wave plate is 45 degrees clockwise to the polarization direction of the linear polarized light, that is, -45°, and the emitted light will be left-handed circularly polarized light. The rotating electric field of the left-handed circularly polarized light is matched with the diffraction optical element of the beam shaping device 5 to make the energy of the side lobe less than 10%, and will not cause side lobe damage to the drilling in the application of TGV laser drilling.

[0032] In some embodiments, the radiation device is a laser, which can generate linear polarized light and input the linear polarized light into the polarization adjustment device 1. As a radiation device, the laser can provide highly stable linear polarized light output. Compared with traditional light sources, lasers have the characteristics of narrow line width, high brightness and good coherence, which makes the generated linear polarized light more stable and reliable.

[0033] It should be noted that other types of ray devices can be used, such as using a traditional light source with a polarizer to produce linear polarization, but this method is more complicated to produce linear polarization, and the stability is not as good as the linear polarization produced by a laser. More importantly, when the polarizer is set, the power loss of light passing through the polarizer is very serious, affecting subsequent processing operations.

[0034] In some embodiments, the polarization adjustment device 1 further includes a rotating mount 7, on which a quarter wave plate is fixedly mounted, and the rotating mount 7 can drive the quarter wave plate to rotate so as to change the fast axis direction of the quarter wave plate. The quarter wave plate is fixed on the rotating mount 7, and the angle of the quarter wave plate relative to the incident light can be precisely adjusted by rotating the mount 7. Since the change of the polarization state of the light by the quarter wave plate depends on the angle between its optical axis and the polarization direction of the incident light, the polarization state of the light can be precisely adjusted from linear polarized light to circular polarized light, elliptically polarized light, and linear polarized light of different polarization directions by rotating the mount 7, which has a wider range of adaptability. At the same time, the quarter wave plate is fixedly mounted on the rotating mount 7, which can ensure the stability of the wave plate during the adjustment process.

[0035] In some embodiments, the quarter wave plate is a polymer true zero-order quarter wave plate 4, which has a high tolerance to the angle of incident light. Even if the angle of the incident light has a certain deviation, the polymer true zero-order quarter wave plate 4 can still effectively achieve polarization conversion.

[0036] It should be noted that a quarter wave plate can also be used as a zero-order quarter wave plate if the requirements for use are met, but the performance of the zero-order quarter wave plate is not as good as the polymer true zero-order quarter wave plate 4. For example, the zero-order wave plate has relatively strict requirements on the angle of the incident light. When the angle of the incident light exceeds a certain range, its polarization conversion effect will be significantly affected.

[0037] As a preferred embodiment, the polymer true zero-order quarter wave plate 4 includes a glass substrate layer, a liquid crystal polymer functional film layer and a glass substrate layer arranged in sequence. The three-layer structure is glued and bonded in sequence, which can combine the advantages of different materials, reduce the overall birefringence non-uniformity, and the polymer true zero-order quarter wave plate 4 produced by gluing can enhance the overall mechanical strength by gluing a thin crystal material (liquid crystal polymer functional film layer) on a solid substrate (glass substrate layer).

[0038] It should be noted that the quarter-wave plate can also be a true zero-order quarter-wave plate made of a single piece. The single-piece true zero-order quarter-wave plate is made of only one piece of quartz material. The selection and processing requirements of the quartz material are very high, and the thickness and uniformity of the quartz plate need to be precisely controlled to ensure that it can accurately produce a quarter-wavelength phase delay. However, the wave plate made of a single piece may have uneven birefringence inside the material, which will affect the polarization conversion effect of the wave plate on light. In addition, the wave plate made of a single piece may be easily damaged by external forces during use due to the brittleness or thickness limitation of the material.

[0039] In some embodiments, the Bessel light generating element 52 is a flat axon diffractive optical element. The flat axon diffractive optical element can be used to realize annular convergence or divergence of light beams, can be used to generate Bessel light beams, and is made of liquid crystal material, has large birefringence and high transmittance, and the flat axon diffractive optical element has a continuous phase, and after the light passes through, there will be no significant loss of energy, and the energy utilization rate is very high. Compared with some traditional optical elements such as optical elements produced by etching, the energy utilization rate is higher. It should be noted that the Bessel light generating element 52 can also use other elements such as optical elements produced by etching, but the phase of the optical element produced by etching cannot be continuous, and there will be a large energy loss when the light passes through, affecting the processing effect and efficiency.

[0040] In some embodiments, the double telecentric optical system 8 includes a lens and an objective lens connected in sequence, the lens is aligned with the end of the beam shaping device 5, and the objective lens is aligned with the end of the lens away from the beam shaping device. By changing the focal length of the objective lens and the lens, the beam reduction ratio of the double telecentric optical system 8 can be adjusted, thereby regulating the drilling depth and drilling position of the light beam. The change of the beam reduction ratio can change the focusing degree of the light beam, thereby adjusting the penetration depth of the light energy in the material. The beam reduction ratio can be accurately adjusted according to specific processing requirements to achieve the required drilling depth and improve the processing accuracy and quality. In addition, the double telecentric optical system 8 has good optical performance, high imaging quality, and can reduce various optical aberrations, so that the light beam can maintain high quality and stability after passing through the optical system, and improve the processing accuracy and consistency. For example, in high-precision laser processing, the reduction of optical aberrations can ensure that the shape and energy distribution of the spot are more uniform, reducing processing errors and surface roughness.

[0041] In some embodiments, the lens is a plano-convex lens 6 made of fused silica, and the objective lens is a high-power laser objective lens 3 with a magnification of not less than 5 times. The focal length f1 of the planar lens, the focal length f2 of the high-power laser objective lens 3, and the beam reduction ratio m (f2 / f1) of the double telecentric optical system 8 determine the non-diffraction distance (i.e., air focal depth) Z of the terminal light beam. max2 , this parameter affects the actual machining cutting depth and also determines the deflection angle θ2.

[0042] It should also be noted that the sidelobe-eliminating Bessel beam drilling device of this embodiment has a relatively high damage threshold in experimental tests of the light source parameters: repetition rate 50KHz, incident spot size 6mm(e-2), pulse width <12ps, single pulse energy 600μJ.

[0043] In some embodiments, the beam shaping device 5 and the control device are both fixedly installed in the metal sleeve 2, achieving high integration and convenient installation of each component. At the same time, metal materials generally have high strength and rigidity, and can provide firm support for the internal optical device.

[0044] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A sidelobe-eliminating Bessel beam drilling device, characterized in that: include A light generating device, the light generating device is used to generate circularly polarized light; A beam shaping device, the beam shaping device comprising a binary phase plate diffractive optical element and a Bessel light generating element, the binary phase plate diffractive optical element is arranged at the end of the light generating device, the Bessel light generating element is arranged at the end of the binary phase plate diffractive optical element, the binary phase plate diffractive optical element is used to modulate the phase of the circularly polarized light, the Bessel light generating element is used to convert the circularly polarized light passing through the binary phase plate diffractive optical element into a Bessel light beam, when the circularly polarized light passes through the 0 phase region of the binary phase plate diffractive optical element and then enters the Bessel light generating element, a first type of Bessel light beam can be generated; when the circularly polarized light passes through the π phase region of the binary phase plate diffractive optical element and then enters the Bessel light generating element, a second type of Bessel light beam can be generated, and the first type of Bessel light beam and the second type of Bessel light beam can have side lobe destructive interference and main lobe constructive interference; The regulating device includes a double telecentric optical system and is arranged at the end of the beam shaping device, and can regulate the drilling depth and drilling position of the light beam.

2. The sidelobe-eliminating Bessel beam drilling device according to claim 1, characterized in that: The light generating device comprises a ray device and a polarization adjusting device, one end of the polarization adjusting device is aligned with the ray device, and the other end is aligned with the beam shaping device, the ray device is used to transmit light to the polarization adjusting device, and the polarization adjusting device comprises a quarter wave plate, and the fast axis direction of the quarter wave plate forms an angle of -45° with the polarization direction of the light.

3. The sidelobe-eliminating Bessel beam drilling device according to claim 2, characterized in that: The ray device is a laser, which can generate linear polarized light and direct the linear polarized light into the polarization adjustment device.

4. The sidelobe-eliminating Bessel beam drilling device according to claim 3, characterized in that: The polarization adjustment device further comprises a rotating mounting seat, the quarter wave plate is fixedly arranged on the rotating mounting seat, and the rotating mounting seat can drive the quarter wave plate to rotate.

5. The sidelobe-eliminating Bessel beam drilling device according to claim 2, characterized in that: The quarter wave plate is a polymer true zero-order quarter wave plate, and the polymer true zero-order quarter wave plate comprises a glass substrate layer, a liquid crystal polymer functional film layer and a glass substrate layer which are arranged in sequence.

6. The sidelobe-eliminating Bessel beam drilling device according to claim 1, characterized in that: The Bessel light generating element is a flat axicon diffractive optical element.

7. The sidelobe-eliminating Bessel beam drilling device according to claim 1, characterized in that: The double telecentric optical system comprises a lens and an objective lens which are arranged in sequence, wherein the lens is aligned with the end of the beam shaping device, and the objective lens is aligned with an end of the lens away from the beam shaping device. By changing the focal lengths of the objective lens and the lens, the beam reduction ratio of the double telecentric optical system can be adjusted to control the drilling depth and drilling position of the light beam.

8. The sidelobe-eliminating Bessel beam drilling device according to claim 7, characterized in that: The lens is a plano-convex lens made of fused quartz.

9. The sidelobe-eliminating Bessel beam drilling device according to claim 7, characterized in that: The objective lens is a high-power laser objective lens with a magnification of not less than 5 times.

10. The sidelobe-eliminating Bessel beam drilling device according to claim 1, characterized in that: The beam shaping device and the regulating device are both fixedly installed in the metal sleeve.

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