Ultraviolet ultrafast laser telecentric lens group and laser processing equipment

Abstract

The embodiment of the invention discloses an ultraviolet ultrafast laser telecentric lens group and laser processing equipment, the ultraviolet ultrafast laser telecentric lens group comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens which are sequentially arranged along the incident direction of light, the first lens is a biconvex positive lens, the second lens is a biconcave negative lens, and the fifth lens is a biconvex negative lens. The third lens is a negative meniscus lens, the fourth lens is a positive meniscus lens, and the fifth lens is a biconvex positive lens. According to the ultraviolet ultrafast laser telecentric lens group, an exit pupil is located at the infinite position of an image space, main light rays of a focused light beam are perpendicular to a focal plane under the condition of any full field angle, perforation inclination is avoided, astigmatism and distortion of the laser telecentric lens group are effectively corrected, an image space telecentric light path is achieved, and the imaging quality is improved. In addition, the lens is simple in structure and convenient to design, and can be widely applied to various fine laser processing devices.

Description

Technical Field

[0001] The present application relates to the technical field of optical lens groups and laser lenses, and in particular to an ultraviolet ultrafast laser telecentric lens group and ultraviolet laser lens fine processing equipment. Background Art

[0002] The shorter the wavelength of the laser, the finer the focused spot can be. In the field of industrial laser processing, the pulse frequency of pulsed lasers is getting faster and faster. Ultraviolet lasers with a pulse width of 500 femtoseconds have been widely used in the field of ultra-fine processing, especially in the display panel (mini-LED) industry. The 500Fs ultraviolet laser in the 343nm band has been developed quite maturely, and the power has been increasing, which makes many ultra-fine industrial processing possible.

[0003] At present, when using non-ultraviolet ultrafast laser telecentric lens group for drilling, there is a certain inclination angle between the image side principal ray and the focal plane, resulting in a certain slope of the processed hole. In addition, when the processed object is defocused to a certain extent from the non-ultraviolet ultrafast laser telecentric lens group, additional distortion will be caused, reducing the processing accuracy.

[0004] Therefore, when performing laser drilling, how to avoid drilling tilt, correct the astigmatism and distortion of the laser telecentric lens group, realize the image-side telecentric optical path, and improve the imaging quality has become a technical problem that needs to be solved urgently. Summary of the invention

[0005] The embodiments of the present application provide an ultraviolet ultrafast laser telecentric lens group and laser processing equipment to solve the problem of how to avoid drilling tilt during laser drilling, and correct the astigmatism and distortion of the laser telecentric lens group, thereby realizing the image-side telecentric optical path and improving the imaging quality, which has become a technical problem that needs to be solved urgently.

[0006] In order to solve the above technical problems, the present application provides an ultraviolet ultrafast laser telecentric lens group, which adopts the following technical solution:

[0007] A ultraviolet ultrafast laser telecentric lens group comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens which are arranged in sequence along the incident direction of light, wherein the first lens is a double convex positive lens, the second lens is a double concave negative lens, the third lens is a meniscus negative lens, the fourth lens is a meniscus positive lens and the fifth lens is a double convex positive lens.

[0008] Furthermore, the focal length of the ultraviolet ultrafast laser telecentric lens group is 500 mm, the full field angle is 32°, the allowable tolerance of the ultraviolet ultrafast laser telecentric lens group is 10%, the upper deviation is +5%, and the lower deviation is -5%.

[0009] Furthermore, the first lens includes a first curved surface and a second curved surface, the second lens includes a third curved surface and a fourth curved surface, the third lens includes a fifth curved surface and a sixth curved surface, the fourth lens includes a seventh curved surface and an eighth curved surface, and the fifth lens includes a ninth curved surface and a tenth curved surface, wherein the first curved surface to the tenth curved surface are arranged in sequence along the direction of the incident light, and the curvature radii of the first curved surface to the tenth curved surface are 148.5mm, -265mm, -171.5mm, 133.5mm, -104mm, -170.5mm, -1395mm, -258mm, 947.5mm, and -345.5mm, respectively, and the allowable tolerance of the curvature radius is 10%, the upper deviation is +5%, and the lower deviation is -5%.

[0010] Furthermore, the spacing between the second curved surface and the third curved surface on the optical axis is 16 mm, the spacing between the fourth curved surface and the fifth curved surface on the optical axis is 94 mm, the spacing between the sixth curved surface and the seventh curved surface on the optical axis is 18 mm, and the spacing between the eighth curved surface and the ninth curved surface on the optical axis is 1 mm respectively. The allowable tolerance of the spacing is 10%, the upper deviation is +5%, and the lower deviation is -5%.

[0011] Furthermore, the center thicknesses of the first lens to the fifth lens on the optical axis are 87 mm, 9 mm, 50 mm, 33.5 mm, and 46 mm, respectively, and the allowable tolerance of the center thickness is 10%, the upper deviation is +5%, and the lower deviation is -5%.

[0012] Furthermore, the ratio of the refractive index to the Abbe number of the first lens, the second lens, the third lens, the fourth lens and the fifth lens is 1.4585 / 67.82, the allowable tolerance of the ratio of the refractive index to the Abbe number is 10%, the upper deviation is +5%, and the lower deviation is -5%.

[0013] Furthermore, the entrance pupil diameter of the ultraviolet ultrafast laser telecentric lens group is 20 mm.

[0014] Furthermore, the telecentricity of the ultraviolet ultrafast laser telecentric lens group is less than 3.2°.

[0015] Furthermore, the wavelength of the incident beam of the ultraviolet ultrafast laser telecentric lens group is 343 nm, and the pulse width is 500 fs.

[0016] In order to solve the above technical problems, the embodiment of the present application further provides a laser processing device, which adopts the following technical solution:

[0017] A laser processing device comprises the ultraviolet ultrafast laser telecentric lens group as described above.

[0018] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0019] The embodiment of the present application discloses an ultraviolet ultrafast laser telecentric lens group and laser processing equipment. The ultraviolet ultrafast laser telecentric lens group includes a first lens, a second lens, a third lens, a fourth lens and a fifth lens arranged in sequence along the incident direction of the light. The first lens is a double convex positive lens, the second lens is a double concave negative lens, the third lens is a meniscus negative lens, the fourth lens is a meniscus positive lens, and the fifth lens is a double convex positive lens. The ultraviolet ultrafast laser telecentric lens group of the present application makes the exit pupil infinitely far away in the image space, and the main light of the focused light beam is perpendicular to the focal plane under any full field of view angle, avoiding the tilt of the punching, and effectively correcting the astigmatism and distortion of the laser telecentric lens group, realizing the image-side telecentric optical path, and improving the imaging quality. In addition, the lens structure of the present application is simple and easy to design, and can be widely used in various fine laser processing equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the solutions in the present application or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 is a schematic structural diagram of an ultraviolet ultrafast laser telecentric lens group in one embodiment;

[0022] Figure 2 is a geometric phase difference curve diagram of a UV ultrafast laser telecentric lens group in one embodiment;

[0023] Figure 3 is a distortion curve diagram of a UV ultrafast laser telecentric lens assembly in one embodiment;

[0024] Figure 4 is an optical transfer function OTF curve diagram of a UV ultrafast laser telecentric lens group in one embodiment;

[0025] Figure 5 is an MTF curve diagram of the transfer function of the ultraviolet ultrafast laser telecentric lens group in one embodiment;

[0026] Figure 6 Schematic diagram of the diffused spots of the ultraviolet ultrafast laser telecentric lens group in one embodiment;

[0027] Figure 7 Schematic diagram of energy concentration of a UV ultrafast laser telecentric lens assembly in one embodiment. DETAILED DESCRIPTION

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of this application; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0029] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0030] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0031] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "inside", "outside", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0032] It should be noted that when light propagates from left to right, the intersection of the spherical surface and the principal optical axis is taken as the standard. If the center of the spherical surface is to the left of this point, the radius of curvature is negative. On the contrary, if the center of the sphere is to the right of this point, the radius of curvature is positive. In addition, in this article, the incident light propagates from left to right, and the left side of the lens is the object side, and the right side of the lens is the image side.

[0033] At present, when using non-ultraviolet ultrafast laser telecentric lens group for drilling, there is a certain inclination angle between the image side principal ray and the focal plane, resulting in a certain slope of the processed hole. In addition, when the processed object is defocused to a certain extent from the non-ultraviolet ultrafast laser telecentric lens group, additional distortion will be caused, reducing the processing accuracy.

[0034] The ultraviolet ultrafast laser telecentric lens group in the F-Theta lens refers to the image-side telecentric optical path, where the image-side principal ray is parallel to the optical axis and the convergence center of the principal ray is located at infinity on the image side. Compared with ordinary laser F-Theta lenses, more precise wide-angle end accuracy can be obtained, the overall distortion of the working surface is smaller, and a relatively uniform focus spot diameter can be obtained within the entire scanning range, which is a very important goal in ultra-fine processing.

[0035] Based on this, the present application discloses an ultraviolet ultrafast laser telecentric lens assembly and laser processing equipment to solve the above technical problems. Figure 1 As shown, an ultraviolet ultrafast laser telecentric lens group 100 includes a first lens 10, a second lens 20, a third lens 30, a fourth lens 40 and a fifth lens 50 arranged in sequence along the incident direction of light, the first lens 10 is a double convex positive lens, the second lens 20 is a double concave negative lens, the third lens 30 is a meniscus negative lens, the fourth lens 40 is a meniscus positive lens, and the fifth lens 50 is a double convex positive lens. The focal length of the ultraviolet ultrafast laser telecentric lens group 100 is 500 mm, the allowable tolerance is 10%, the upper deviation is +5%, the lower deviation is -5%, and the full field of view angle is 32°.

[0036] In order to obtain a more precise processing area, it is necessary to minimize the scanning field of view of the ultraviolet ultrafast laser telecentric lens group 100. The focal length of the ultraviolet ultrafast laser telecentric lens group 100 is designed to be 500mm, and the full field of view angle is 32°. Without moving the processing object or the workbench, the scanning field of view of the ultraviolet ultrafast laser telecentric lens group 100 of the present invention is 200mm*200mm, which can obtain ultra-fine processing accuracy.

[0037] In a specific embodiment of the present application, the ultraviolet ultrafast laser telecentric lens group 100 of the present application is specially designed so that the exit pupil is infinitely far away in the image space, and the main ray of the focused light beam is perpendicular to the focal plane under any full field of view angle, which can avoid tilting of the drilling and reduce the distortion caused by slight defocus of the processed object, thereby achieving the purpose of ultra-fine processing.

[0038] The ultraviolet ultrafast laser telecentric lens assembly 100 of the present application effectively corrects astigmatism and distortion, realizes the image-side telecentric optical path, and improves the imaging quality through the design of the shapes and relative positions of the first lens 10, the second lens 20, the third lens 30, the fourth lens 40, and the fifth lens 50. At the same time, the laser energy concentration is high, and the lens structure is simple and easy to design, and can be widely used in various fine laser processing equipment.

[0039] The wavelength λ of the incident laser beam of the ultraviolet ultrafast laser telecentric lens assembly 100 is 343 nm.

[0040] In a specific embodiment of the present application, the spot diameter after focusing is calculated according to the theoretical calculation formula of the diffuse spot after laser focusing:

[0041] spotΦ=1.83*λ*EFL / beamΦ

[0042] In the formula, spotΦ is the spot diameter after focusing (that is, the diffuse spot size after focusing);

[0043] λ is the laser wavelength of the processing beam;

[0044] EFL is the focal length of the UV ultrafast laser telecentric lens set 100;

[0045] beamΦ is the entrance pupil diameter of the ultraviolet ultrafast laser telecentric lens assembly 100 .

[0046] It can be seen from the above formula that a focused spot diameter of 15 μm can be obtained, and cutting with an ultra-short wavelength laser beam will obtain a finer tangent width. The wavelength λ of the ultraviolet laser currently used in this embodiment is 343 nm, and theoretically its resolution is three times greater than that of a laser with a wavelength of 1064 nm. Since the materials of the first lens 10, the second lens 20, the third lens 30, the fourth lens 40, and the fifth lens 50 of the ultraviolet ultrafast laser telecentric lens group 100 are all fused quartz, the ultraviolet ultrafast laser telecentric lens group 100 can be applied to the ultraviolet band laser λ=343 nm, and a very high resolution point distance can be obtained, that is, an ultra-fine diffuse spot can be obtained after focusing. Due to the characteristics of fused quartz, the ultraviolet ultrafast laser telecentric lens group 100 is suitable for high power density, that is, it can be applied to a 20w picosecond ultraviolet laser.

[0047] The entrance pupil diameter beamΦ of the ultraviolet ultrafast laser telecentric lens group 100 is 20 mm, which ensures the amount of light passing per unit time while making the ultraviolet ultrafast laser telecentric lens group 100 have a relatively small volume.

[0048] In a specific embodiment of the present application, the first lens 10 is composed of a first curved surface 11 and a second curved surface 12, the second lens 20 is composed of a third curved surface 21 and a fourth curved surface 22, the third lens 30 is composed of a fifth curved surface 31 and a sixth curved surface 32, the fourth lens 40 is composed of a seventh curved surface 41 and an eighth curved surface 42, and the fifth lens 50 is composed of a ninth curved surface 51 and a tenth curved surface 52, wherein the first curved surface 11 to the tenth curved surface 52 are arranged in sequence along the direction of the incident light, the curvature radius of the first curved surface 11 is 148.5±5% mm, and the curvature radius of the second curved surface 12 is -2 65±5%mm, the radius of curvature of the third curved surface 21 is -171.5±5%mm, the radius of curvature of the fourth curved surface 22 is 133.5±5%mm, the radius of curvature of the fifth curved surface 31 is -104±5%mm, the radius of curvature of the sixth curved surface 32 is -170.5±5%mm, the radius of curvature of the seventh curved surface 41 is -1395±5%mm, the radius of curvature of the eighth curved surface 42 is -258±5%mm, the radius of curvature of the ninth curved surface 51 is 947.5±5%mm, and the radius of curvature of the tenth curved surface 52 is -345.5±5%mm.

[0049] In a specific embodiment of the present application, the center thickness d1 of the first lens 10 on the optical axis is 87±5% mm, the center thickness d2 of the second lens 20 on the optical axis is 9±5% mm, the center thickness d3 of the third lens 30 on the optical axis is 50±5% mm, the center thickness d4 of the fourth lens 40 on the optical axis is 33.5±5% mm, and the center thickness d5 of the fifth lens 50 on the optical axis is 46±5% mm.

[0050] In a specific embodiment of the present application, the spacing S1 between the second curved surface 12 and the third curved surface 21 on the optical axis is 16±5% mm, the spacing S2 between the fourth curved surface 22 and the fifth curved surface 31 on the optical axis is 94±5% mm, the spacing S3 between the sixth curved surface 32 and the seventh curved surface 41 on the optical axis is 18±5% mm, and the spacing S4 between the eighth curved surface 42 and the ninth curved surface 51 on the optical axis is 1±5% mm.

[0051] In a specific embodiment of the present application, the ratio of the refractive index of the first lens 10 to the Abbe number is 1.4585 / 67.82±5%, the ratio of the refractive index of the second lens 20 to the Abbe number is 1.4585 / 67.82±5%, the ratio of the refractive index of the third lens 30 to the Abbe number is 1.4585 / 67.82±5%, the ratio of the refractive index of the fourth lens 40 to the Abbe number is 1.4585 / 67.82±5%, and the ratio of the refractive index of the fifth lens 50 to the Abbe number is 1.4585 / 67.82±5%.

[0052] In a specific embodiment of the present application, the structural parameters of the ultraviolet ultrafast laser telecentric lens assembly 100 are shown in the following table:

[0053] Table 1 Structural parameters of the ultraviolet ultrafast laser telecentric lens assembly 100

[0054]

[0055] Depend on Figure 2 and Figure 3 It can be seen that the ultraviolet ultrafast laser telecentric lens group 100 effectively alleviates the field curvature and distortion problems through precise correction, thereby improving the imaging quality within the entire scanning range. The image surface is flat and the astigmatism is small, ensuring that the imaging is very accurate both in the center and edge areas of the optical axis. This high-precision imaging capability makes the lens group particularly suitable for fields that require ultra-fine and high-precision processing, especially in high-demand application scenarios such as ultraviolet ultrafast laser processing.

[0056] Through optimization, the field curvature and distortion problems of the UV ultrafast laser telecentric lens group have been effectively solved. Field curvature refers to the difference in curvature of the image plane at different positions, which usually causes the image to be distorted in the edge area. Distortion refers to the deformation of the image geometry, such as stretching or compression. After correction, the flattening of the image plane means that the focal plane of the image has been optimized, reducing distortion or distortion, and significantly improving the clarity and accuracy of the image.

[0057] Moreover, the lens group performs uniformly throughout the entire scanning range, and the image quality remains consistent, with no obvious aberration or distortion, whether axially (center of the optical axis) or off-axis (area deviating from the optical axis). This shows that the imaging effect of the lens group is very stable in various positions and is suitable for high-precision optical applications.

[0058] Astigmatism refers to the asymmetry of imaging caused by imperfect or improperly designed lenses, which is usually manifested as elongation or compression of the image in certain directions. After using the ultraviolet ultrafast laser telecentric lens set 100, the astigmatism is smaller, that is, when the lens set is used for imaging, the point spread of the image is less, thereby improving the resolution. Smaller astigmatism means that the system can provide higher accuracy in ultra-fine and high-precision processing, especially in the fields of laser processing and micro-processing, and can obtain more accurate workpiece surface quality.

[0059] Depend on Figure 4 and Figure 5They respectively represent the performance of the optical transfer function (OTF) and the transfer function (MTF) of the ultraviolet ultrafast laser telecentric lens group 100 for ultraviolet laser. OTF is a function that describes the ability of an optical system to transfer different spatial frequency components in the spatial frequency domain, reflecting the overall imaging quality of the system. OTF can characterize the response of the system under different conditions, especially the ability to transfer different frequencies (details). MTF is the concretization of the contrast transfer function, which indicates the ability of the system to transfer image contrast. It is usually used to measure the resolution of the system at different spatial frequencies, reflecting the clarity and resolution of the system in imaging. These two functions are important tools for evaluating the imaging performance of optical systems. They can quantify how the system transfers optical information of different spatial frequencies, thereby helping to analyze the imaging quality.

[0060] Depend on Figure 4 and Figure 5 It can also be seen that there is no obvious difference between the on-axis point and the off-axis point of the ultraviolet ultrafast laser telecentric lens group 100 for ultraviolet laser, that is, whether it is in the center of the optical axis or in the area deviating from the optical axis, the clarity, contrast and resolution of the image are consistent, achieving the purpose of flat field. Flat field means that the focal plane of the imaging system is flat within the entire field of view, and the image quality is consistent at all positions without significant distortion or aberration. The analysis of OTF and MTF shows that the lens group has reached this ideal state and can provide consistent imaging effects throughout the entire scanning or observation range, especially in the axis and off-axis areas.

[0061] Figure 6 and Figure 7 It shows the diffuse spot and energy concentration of the ultraviolet laser after using the ultraviolet ultrafast laser telecentric lens set 100. The size of the diffuse spot in all fields of view is controlled at about 15μm, and all cutting energy is concentrated at about 15μm. It can be seen that after using the ultraviolet ultrafast laser telecentric lens set 100, the laser energy concentration is extremely high, so that precise marking or cutting can be achieved.

[0062] The diffuse spot is the shape of the light spot at the focal point after the laser is focused by the lens. The size and shape of the diffuse spot reflect the focusing quality of the laser. A light spot with a small range and regular shape indicates that the laser has a good focusing effect and is suitable for high-precision processing.

[0063] Energy concentration refers to the concentration of the energy of the laser beam in the focal area. High concentration means that most of the laser energy is concentrated in a small range, thereby improving processing accuracy and efficiency.

[0064] After using the UV ultrafast laser telecentric lens set 100, the size of the diffuse spot remains consistent in different fields of view and is controlled at about 15μm, indicating that the lens set has good optical quality and can maintain a stable focusing effect in different working ranges. The size of the diffuse spot is 15μm, which means that the laser beam has a very small spot at the focal point and has a very high precision, which is suitable for micro-machining. All cutting energy is concentrated around 15μm, and the energy of the laser is almost completely concentrated in a very small area. This high energy concentration is crucial for fine processing (such as laser cutting, marking, etc.), and can generate high temperatures in a small range, thereby effectively processing materials.

[0065] In summary, the ultraviolet ultrafast laser telecentric lens assembly 100 ensures the stability and efficiency of the laser in different fields of view by improving the focusing accuracy and energy concentration of the laser, and is particularly suitable for laser processing applications that require high precision and high energy density.

[0066] In another specific embodiment of the present application, the present application also discloses a laser processing equipment, specifically ultraviolet laser fine processing equipment, including an ultraviolet laser and an ultraviolet ultrafast laser telecentric lens group 100 for focusing the ultraviolet laser. The above-mentioned laser processing equipment can be a laser drilling machine, a laser marking machine or a laser cutting machine.

[0067] The emission wavelength of the ultraviolet laser is 343nm, and the power of the ultraviolet laser is equal to or greater than 20W. The laser processing equipment also includes a beam expander, an X-galvanometer and a Y-galvanometer. The laser emitted by the ultraviolet laser passes through the beam expander, the X-galvanometer and the Y-galvanometer in sequence, and finally focuses on the image plane through the ultraviolet ultrafast laser telecentric lens group 100. The scanning field of view of the ultraviolet ultrafast laser telecentric lens group 100 reaches 200mm*200mm, which can meet the needs of ultra-fine processing areas and effectively improve production efficiency. Furthermore, the main light of the ultraviolet ultrafast laser telecentric lens group 100 to each field of view is perpendicular to the image plane, thereby avoiding the tilt of the punching, and at the same time, it can avoid the distortion caused by slight defocus of the processed object, thereby ensuring the processing accuracy. At the same time, since the astigmatism of the ultraviolet ultrafast laser telecentric lens group 100 is small, it can avoid the drastic changes in the processing shape caused by slight defocus or tilt of the processed object.

[0068] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described implementation modes are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0069] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

[0070] Obviously, the embodiments described above are only some embodiments of the present application, rather than all embodiments. The preferred embodiments of the present application are given in the accompanying drawings, but they do not limit the patent scope of the present application. The present application can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive. Although the present application is described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions recorded in the aforementioned specific implementation methods, or to perform equivalent replacement of some of the technical features therein. Any equivalent structure made using the contents of the specification and drawings of this application, directly or indirectly used in other related technical fields, is similarly within the scope of patent protection of this application.

Claims

1. A UV ultrafast laser telecentric lens assembly, characterized in that: The invention comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens which are arranged in sequence along the incident direction of light, wherein the first lens is a biconvex positive lens, the second lens is a biconcave negative lens, the third lens is a meniscus negative lens, the fourth lens is a meniscus positive lens, and the fifth lens is a biconvex positive lens.

2. The ultraviolet ultrafast laser telecentric lens assembly according to claim 1, characterized in that: The focal length of the ultraviolet ultrafast laser telecentric lens group is 500 mm, the full field angle is 32°, the allowable tolerance of the ultraviolet ultrafast laser telecentric lens group is 10%, the upper deviation is +5%, and the lower deviation is -5%.

3. The ultraviolet ultrafast laser telecentric lens assembly according to claim 1, characterized in that: The first lens includes a first curved surface and a second curved surface, the second lens includes a third curved surface and a fourth curved surface, the third lens includes a fifth curved surface and a sixth curved surface, the fourth lens includes a seventh curved surface and an eighth curved surface, and the fifth lens includes a ninth curved surface and a tenth curved surface, wherein the first to tenth curved surfaces are arranged in sequence along the direction of the incident light, and the curvature radii of the first to tenth curved surfaces are 148.5mm, -265mm, -171.5mm, 133.5mm, -104mm, -170.5mm, -1395mm, -258mm, 947.5mm, and -345.5mm, respectively, and the allowable tolerance of the curvature radius is 10%, the upper deviation is +5%, and the lower deviation is -5%.

4. The ultraviolet ultrafast laser telecentric lens assembly according to claim 3, characterized in that: The spacing between the second curved surface and the third curved surface on the optical axis is 16 mm, the spacing between the fourth curved surface and the fifth curved surface on the optical axis is 94 mm, the spacing between the sixth curved surface and the seventh curved surface on the optical axis is 18 mm, and the spacing between the eighth curved surface and the ninth curved surface on the optical axis is 1 mm respectively. The allowable tolerance of the spacing is 10%, the upper deviation is +5%, and the lower deviation is -5%.

5. The ultraviolet ultrafast laser telecentric lens assembly according to claim 1, characterized in that: The center thicknesses of the first lens to the fifth lens on the optical axis are 87 mm, 9 mm, 50 mm, 33.5 mm, and 46 mm, respectively. The allowable tolerance of the center thickness is 10%, the upper deviation is +5%, and the lower deviation is -5%.

6. The ultraviolet ultrafast laser telecentric lens assembly according to claim 1, characterized in that: The ratio of the refractive index to the Abbe number of the first lens, the second lens, the third lens, the fourth lens and the fifth lens is 1.4585 / 67.82, and the allowable tolerance of the ratio of the refractive index to the Abbe number is 10%, the upper deviation is +5%, and the lower deviation is -5%.

7. The ultraviolet ultrafast laser telecentric lens assembly according to claim 1, characterized in that: The entrance pupil diameter of the ultraviolet ultrafast laser telecentric lens group is 20 mm.

8. The ultraviolet ultrafast laser telecentric lens assembly according to claim 1, characterized in that: The telecentricity of the ultraviolet ultrafast laser telecentric lens group is less than 3.2°.

9. The ultraviolet ultrafast laser telecentric lens assembly according to claim 1, characterized in that: The incident light beam wavelength of the ultraviolet ultrafast laser telecentric lens group is 343nm, and the pulse width is 500fs.

10. A laser processing device, characterized in that: The laser processing equipment comprises the ultraviolet ultrafast laser telecentric lens assembly as described in any one of claims 1-9.

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