A laser processing lens and a processing system using the same

Abstract

This invention provides a laser processing lens and its application processing system, belonging to the field of laser beam processing technology. The lens comprises a negative lens group, a positive lens group, and a coupling component. These three components are coaxially arranged vertically with their optical axes coinciding with the incident laser, ensuring stable linear laser transmission. The negative lens group has a negative total optical power, which can diverge and expand the laser beam, increasing the beam divergence angle, balancing the converging effect of the positive lens group, shifting the reflected focus outward, and simultaneously generating negative spherical aberration to counteract the positive spherical aberration of the positive lens group. The positive lens group uses multiple low-power positive lenses arranged at intervals to gradually converge the beam. The lenses are made of materials with a low coefficient of thermal expansion to suppress thermal deformation and focus drift. An air buffer layer is placed between adjacent lenses to block heat conduction and disperse reflected light. The coupling component is located below, receiving the converged beam and coupling it with a high-pressure water jet. This invention can improve focus shift and reduce beam coupling efficiency while preventing the reflected focus from falling inside the lens.

Description

Technical Field

[0001] This invention belongs to the field of laser beam processing technology, specifically relating to a laser processing lens and its application processing system. Background Technology

[0002] Laser processing, as a key technology in advanced manufacturing, is widely used in precision drilling, cutting, and microstructure machining. Water-guided laser processing relies on high-pressure micro-flows to guide laser transmission and utilizes total internal reflection to achieve flexible beam transmission. This significantly reduces the heat-affected zone and improves processing accuracy, making it a preferred solution for high-precision and high-consistency machining.

[0003] The laser processing lens is a core component of water-guided laser processing, and its beam shaping and coupling quality directly determines the system's stability. Referring to Chinese invention patent application number "201811623608.4", existing technologies employ a combination of multiple meniscus lenses and plano-convex lenses to coaxially couple the laser beam with the visible beam, aligning the working plane with the imaging plane and enabling visual monitoring of the processing process. This type of lens, through specific curvature radius, thickness, and spacing design, can correct astigmatism and distortion, meeting the needs of conventional laser processing.

[0004] However, existing laser processing lenses are prone to absorbing laser energy during high-power laser processing, resulting in thermal deformation and thermal drift. This leads to focus shift and reduced beam coupling efficiency, and the reflected focus is prone to fall inside the lens, causing optical damage. Summary of the Invention

[0005] The technical problem to be solved by the present invention is how to avoid the reflected focus falling inside the lens while improving focus offset and beam coupling efficiency. In view of the shortcomings of the prior art, a processing system for laser-processed lenses and their applications is provided.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a laser processing lens, comprising a negative lens group, a positive lens group, and a coupling component; the negative lens group and the positive lens group are coaxially arranged vertically at intervals, and their optical axes coincide with the extension line of the incident laser transmitted vertically from top to bottom; the total optical power of the negative lens group is negative, and it includes at least one negative lens; the positive lens group includes multiple positive lenses, which are arranged at intervals along the extension line of the incident laser; the optical power of the positive lenses is positive and less than a preset weak optical power value; both the positive lenses and the negative lenses are made of a preset material, and the coefficient of thermal expansion of the preset material is lower than a preset low coefficient of thermal expansion; an air buffer layer is provided between adjacent lenses; the coupling component is located below the positive lens group and is configured to receive the converging beam output by the positive lens group and couple with a high-pressure water jet to form a laser beam output.

[0007] Compared to existing technologies, the beneficial effects of the laser processing lens of this invention include: The laser processing lens is composed of a negative lens group, a positive lens group, and a coupling component. The negative lens group and the positive lens group are coaxially spaced vertically with their optical axes coinciding with the incident laser. This arrangement ensures stable linear transmission of the laser as it enters the laser processing lens, avoiding aberrations and coupling offsets caused by off-axis deviations, thus guaranteeing subsequent processing accuracy. Furthermore, the total optical power of the negative lens group is negative and includes at least one negative lens. This allows the incident laser to diverge and expand as it propagates to the negative lens group, increasing the beam divergence angle, reducing the convergence steepness of the subsequent positive lens group, balancing its converging effect, shifting the reflection focus outwards, and gradually increasing the aperture size, thus reducing the power density per unit area. This significantly reduces the thermal shock and distortion of the lens caused by high-power lasers. Simultaneously, negative spherical aberration is generated to counteract the positive spherical aberration generated by the subsequent positive lens group, achieving spherical aberration self-correction for the entire laser processing lens, resulting in high spot quality and focused performance. The system exhibits good consistency, with the positive lens group comprising multiple positive lenses arranged at intervals along the optical path. The optical power of each positive lens is positive and less than the preset weak light power value, thereby reducing the focusing intensity of a single positive lens and gradually smoothing the beam convergence. This avoids abrupt focusing that creates a high-heat internal focal point, instead forming the working focal point only on the outer rear end, reducing heat accumulation and lens damage. Simultaneously, both the negative and positive lenses are made of materials with low thermal expansion coefficients. This not only suppresses thermal expansion deformation under high-power lasers, reducing thermal drift and focal point shift, and ensuring the stability of optical-water coupling, but also ensures that the refractive indices of each lens are consistent, preventing inward shift of the reflection focal point due to interface refraction distortion. An air buffer layer between adjacent lenses blocks heat conduction and disperses reflected light energy, preventing the formation of secondary focal points in the lens gaps after the reflected light paths of multiple lenses intersect, thus avoiding thermal interference between lenses. Finally, the coupling component is located below the positive lens group, receiving the converged beam and coupling it with the high-pressure water jet to form a water-guided laser beam, achieving total internal reflection transmission of the laser within the water flow.

[0008] Optionally, the absolute value of the incident surface radius of curvature of the negative lens is smaller than the absolute value of the exit surface radius of curvature of the negative lens, and the absolute value of the incident surface radius of curvature of the positive lens is smaller than the absolute value of the exit surface radius of curvature of the positive lens.

[0009] Optionally, the thickness of each lens is configured to be calculated using the following formula, and the size of the air buffer layer is 2-8 mm: , Among them, the For minimum thickness, and The The radius of curvature of the incident surface of the lens is given by the following formula: For the lens thickness, the For the maximum thickness, and The The refractive index of the lens is denoted as .

[0010] Optionally, the laser processing lens further includes a lens housing, which is a hollow structure with openings at both ends. The negative lens includes a negative meniscus lens, and the positive lens includes a first biconvex lens, a first positive meniscus lens, and a second positive meniscus lens. The negative meniscus lens, the first biconvex lens, the first positive meniscus lens, and the second positive meniscus lens are arranged alternately in the lens housing from top to bottom, and are all alternately fixed in the lens housing by multiple pressure ring structures that are threaded to the inner wall of the lens housing through their outer walls.

[0011] Optionally, the coupling assembly includes a window and a nozzle. The window is placed flat below the lens housing and corresponds to the lower opening end of the lens housing. The nozzle is installed below the window and a cavity structure is formed between the window and the nozzle. A water inlet is provided on one side of the cavity structure. The nozzle is a hollow structure with openings at the top and bottom, and the central axis of the opening coincides with the extension line of the incident laser, so as to form an outlet at the upper opening end for the coupled laser beam to pass through. The inner diameter of the nozzle gradually decreases from top to bottom.

[0012] Secondly, the present invention also provides a processing system for a laser processing lens application, comprising a motion control module, a laser transmission module, a water jet coupling module, and a laser processing lens as described in any one of claims 1 to 5. The laser processing lens is mounted below the laser output port of the laser transmission module and is drivenly connected to the motion control module. The water jet coupling module is connected to the coupling component of the laser processing lens. The motion control module is configured to clamp and move the workpiece to be processed and is communicatively connected to both the laser transmission module and the water jet coupling module. The motion control module is used for: The water jet coupling module is activated to transmit high-pressure pure water to the coupling component, while the supply parameters of the high-pressure pure water are adjusted to a preset supply range. Determine whether the water flow state at the coupling component is a preset state. If so, drive the laser transmission module to turn on and transmit laser to the laser processing lens. Adjust the supply parameters of the high-pressure pure water and the output parameters of the laser to adapt the laser to the water beam channel and complete the coupling with the water beam; When the workpiece is clamped and fixed, the laser processing lens is driven to move and focus, and the workpiece is driven to move along the preset processing trajectory for processing; Once the workpiece is processed, the laser transmission module is turned off. After a preset time, the water jet coupling module is turned off, and the processing data is collected and stored in the database.

[0013] Compared to existing technologies, the beneficial effects of the processing system for laser processing lenses of the present invention include: The processing system comprises a motion control module, a laser transmission module, a water jet coupling module, and the laser processing lens as described above. Before processing, the motion control module first drives the water jet coupling module to activate and adjust its parameters to a preset range, thereby establishing a stable water flow and a uniform water layer, providing preconditions for laser coupling. Next, the motion control module activates the laser transmission module after determining that the water flow has reached a preset state, thus emitting the laser only after the water flow has stabilized, avoiding damage to the lens caused by laser stunts. Finally, the motion control module adjusts the water pressure and laser... The output parameters adapt the laser to the water jet channel, thereby achieving efficient optical-water coupling and maintaining high coupling efficiency. Subsequently, after the workpiece is clamped, the motion control module can drive the lens to focus and move the workpiece along the trajectory for processing, ensuring that the focus falls precisely on the processing surface. Finally, after processing is completed, the motion control module can first shut down the laser transmission module and then shut down the water jet coupling module after a delay, thereby achieving a process of stopping energy input first and then stopping water flow, avoiding residual heat damage and water path residual interference. With this setting, the modules work together to achieve fully automatic water flow voltage stabilization, laser start-up and shutdown, coupling matching, trajectory processing, and data aggregation, solving the problems of cumbersome manual adjustment, unstable coupling, low processing accuracy, and discontinuous process.

[0014] Optionally, the water jet coupling module includes a water storage tank, a pure water filter, a high-pressure water pump, a water delivery pipeline, and a pressure and flow sensor. The pure water filter is installed on the water storage tank and is connected to the coupling assembly of the laser processing lens through the high-pressure water pump and the delivery pipeline. The pressure and flow sensor is installed inside the delivery pipeline. The motion control module is communicatively connected to the pure water filter, the high-pressure water pump, and the pressure and flow sensor, and is used for: The pure water filter and the high-pressure water pump are turned on in sequence. The actual water pressure value of the delivery pipeline is collected in real time by the pressure and flow sensor. The operating frequency of the high-pressure water pump is adjusted so that the actual water pressure value is within the preset water pressure range.

[0015] Optionally, the laser transmission module includes a laser emitter, a collimating lens group, and a reflecting lens assembly. The motion control module includes a control element, a first power sensor, and a second power sensor. The laser emitter is mounted above the collimating lens group, and the reflecting lens assembly is mounted below the collimating lens group and above the laser processing lens. The first power sensor is mounted between the reflecting lens assembly and the laser processing lens. The second power sensor is mounted below the outlet of the coupling assembly. The control element is communicatively connected to the laser emitter, the first power sensor, and the second power sensor, and is used for: The laser emitter is driven to turn on, so that the laser is transmitted to the laser processing lens through the collimating lens group and the reflecting lens assembly, and the incident laser power of the laser entering the laser processing lens is collected by the first power sensor. The emitted laser power of the laser output through the outlet is collected by the second power sensor, and the optical-water coupling efficiency is calculated based on the following formula: , Among them, the The light-water coupling efficiency is the stated value. The emitted laser power, the The incident laser power; In real time, it is determined whether the optical-water coupling efficiency is within the preset coupling efficiency range. If not, the supply parameter is adjusted. If the optical-water coupling efficiency is outside the preset coupling efficiency range after adjusting the supply parameter, the output power of the laser emitter is synchronously adjusted until the optical-water coupling efficiency is within the preset coupling efficiency range.

[0016] Optionally, the motion control module further includes a three-axis precision motion platform and a suction clamping fixture, both of which are communicatively connected to the control element. The suction clamping fixture is mounted on the reference positioning surface of the three-axis precision motion platform. The control element is also used for: When the workpiece is placed on the reference positioning surface, the adsorption clamping fixture is driven to clamp and adsorb the workpiece, and at the same time, the workpiece processing contour motion reference is established according to the imported initial preset trajectory. The single-axis real-time positioning error compensation amount of the three-axis precision motion platform is calculated according to the following formula, and the preset machining trajectory is generated based on the single-axis real-time positioning error compensation amount and the workpiece machining contour motion reference: , Among them, the The single-axis real-time positioning error compensation amount, the The error attenuation amplitude fitting coefficients, the The time constant, the The error decay time constant, the The inherent static deviation fitting coefficients, the This refers to the duration of continuous processing.

[0017] Optionally, the motion control module further includes an electric lift, which is located on one side of the three-axis precision motion platform and is driven and connected to the laser processing lens. The control element is communicatively connected to the electric lift and is also used for: Based on the position and height of the processing surface of the workpiece, and according to the focal length parameter of the laser processing lens, the laser processing lens is driven to rise and fall as a whole by the electric lifting device, adjusting the distance of the laser processing lens relative to the processing surface to match the focal length parameter. Attached Figure Description

[0018] The present invention will now be described in further detail with reference to the accompanying drawings.

[0019] Figure 1 : A schematic diagram of the structure of the laser processing lens in this embodiment of the invention.

[0020] Figure 2 : A schematic diagram of the connection of the processing system for the laser processing lens in this embodiment of the invention.

[0021] Figure 3 : A partial structural schematic diagram of the processing system used in the laser processing lens in this embodiment of the invention.

[0022] Figure 4 : A point diagram of the optical system of the processing system used in the laser processing lens in this embodiment of the invention.

[0023] Figure 5 : The modulation transfer function diagram of the optical system of the processing system used in the laser processing lens in this embodiment of the invention.

[0024] Figure 6 : A schematic diagram of the reflection focus of each lens in the processing system used for laser processing lenses in this embodiment of the invention.

[0025] Figure 7 : Schematic diagram of wavefront aberration of the optical system of the processing system used in the laser processing lens in this embodiment of the invention.

[0026] Among them, 1-negative lens group, 2-positive lens group, 21-first biconvex lens, 22-first positive meniscus lens, 23-second positive meniscus lens, 3-coupling assembly, 31-window, 32-nozzle, 321-outlet, 33-cavity structure, 331-inlet, 4-lens housing, 41-first pressure ring, 42-second pressure ring, 43-third pressure ring, 44-fourth pressure ring, 5-motion main control module, 6-laser transmission module, 61-laser emitter, 62-collimating lens group, 621-third positive meniscus lens, 622-second biconvex lens, 63-reflecting lens group, 631-first reflector, 632-second reflector, 7-water jet coupling module. Detailed Implementation

[0027] To better understand the present invention, the following embodiments further illustrate the content of the invention, but the scope of protection of the present invention is not limited to the following embodiments. Numerous specific details are set forth in the following description to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the present invention can be practiced without one or more of these details.

[0028] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this invention are used only to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0029] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0030] The following will explain the proper nouns that appear in the embodiments of this application.

[0031] The Abbe number, also known as the "dispersion coefficient," is a parameter that measures the degree of light dispersion in a transparent medium. Generally, the higher the refractive index of the medium, the stronger the dispersion and the smaller the Abbe number; conversely, the lower the refractive index, the less the dispersion and the larger the Abbe number.

[0032] Positive spherical aberration refers to the fact that the surface of a sphere has a stronger ability to converge or diverge light rays in the region far from the optical axis than it does for paraxial light rays. This causes the convergence point of light rays far from the optical axis to be located in the same direction as the convergence point of paraxial light rays, hence the name positive spherical aberration.

[0033] Negative spherical aberration refers to the weaker ability of a spherical surface to converge or diverge light rays in regions far from the optical axis. This causes the point of convergence of light rays far from the optical axis to be located in the opposite direction to the point of convergence of light rays paraxially, hence the name negative spherical aberration. Generally speaking, lenses with converging properties will produce positive spherical aberration, while lenses with diverging properties will produce negative spherical aberration.

[0034] It is important to note that the sign of spherical aberration is determined by the shape of the sphere and the object-image relationship. A convex spherical surface can produce both positive and negative spherical aberration; similarly, a concave spherical surface can also produce both.

[0035] Spherical aberration correction is an important part of optical design. It is usually achieved by using concave and convex spherical surfaces with different curvatures or positive and negative lenses with different curvatures in combination to minimize the spherical aberration of the entire optical system.

[0036] Numerical aperture (NA) is a dimensionless parameter in optical systems used to measure the system's ability to collect light and its resolution. Specifically, a larger NA indicates that the optical system can collect a wider range of light angles. A high NA means the optical system can collect more light energy. For example, in laser lenses, a larger NA results in a smaller laser beam spot under the same incident light conditions, allowing the laser beam to be coupled into a smaller nozzle and enabling smaller diameter water jets.

[0037] The working principle of laser processing equipment is to combine a laser beam with a high-pressure water jet, so that the laser beam is stably confined in the high-pressure water jet and transmitted to the workpiece surface by the water flow. The laser processing lens in the laser processing equipment is usually composed of multiple lenses, which are used to focus the laser beam, thereby enabling the laser beam to be coupled more effectively into the high-pressure water jet.

[0038] In some applications, ordinary optical glass is often used as the lens material for laser processing lenses in laser processing equipment. However, when the laser source is a high-power laser, directly using this laser source may cause problems. High-energy laser beams, under prolonged exposure, can cause thermal drift in the optical system due to high temperatures. Thermal drift may prevent the laser beam from effectively coupling with the water jet and could potentially damage the laser processing equipment.

[0039] To address the aforementioned technical problems, in a first aspect, an embodiment of the present invention provides a laser processing lens, comprising a negative lens group 1, a positive lens group 2, and a coupling component 3; the negative lens group 1 and the positive lens group 2 are coaxially arranged vertically at intervals, and their optical axes coincide with the extension line of the incident laser transmitted vertically from top to bottom; the total optical power of the negative lens group 1 is negative, and it includes at least one negative lens; the positive lens group 2 includes multiple positive lenses, which are arranged at intervals along the extension line of the incident laser; the optical power of the positive lenses is positive and less than a preset weak optical power value; both the positive and negative lenses are made of a preset material, and the coefficient of thermal expansion of the preset material is lower than a preset low coefficient of thermal expansion; an air buffer layer is provided between adjacent lenses; the coupling component 3 is located below the positive lens group 2 and is configured to receive the converging beam output from the positive lens group 2, and couple with a high-pressure water jet to form a laser beam output.

[0040] Specifically, the preset material can be ultraviolet fused silica glass or low thermal expansion coefficient optical glass; the thermal expansion coefficient characterizes the degree of material deformation under heat, and the lower the coefficient, the more stable the dimensions at high temperatures. The preset low thermal expansion coefficient can be 5.1 × 10⁻⁶. -7 / ℃ and below, such as 1×10 -6 / ℃; the preset low-light focal length value can be 0.05mm. -1 or 0.08mm -1 .

[0041] In this embodiment, as Figure 1As shown, a laser processing lens is composed of a negative lens group 1, a positive lens group 2, and a coupling component 3. The negative lens group 1 and the positive lens group 2 are coaxially spaced vertically with their optical axes coinciding with the incident laser. This arrangement ensures stable linear transmission of the laser as it enters the lens, avoiding aberrations and coupling offsets caused by off-axis deviations, thus guaranteeing subsequent processing accuracy. Furthermore, the negative lens group 1 has a negative total optical power and contains at least one negative lens. When the incident laser propagates to the negative lens group 1, it can diverge and expand the beam, increasing the divergence angle and reducing the convergence steepness of the subsequent positive lens group 2. This balances the converging effect of the positive lens group 2, shifting the reflection focus outwards. The aperture gradually increases, reducing the power density per unit area and significantly reducing the thermal shock and distortion of the lens caused by high-power lasers. Simultaneously, it generates negative spherical aberration to counteract the positive spherical aberration generated by the subsequent positive lens group, achieving spherical aberration self-correction for the entire laser processing lens. This results in high spot quality and good focusing consistency. Meanwhile, the positive lens group... 2. The system comprises multiple positive lenses arranged at intervals along the optical path. The optical power of each positive lens is positive and less than the preset weak light power value, thereby reducing the focusing intensity of a single positive lens and gradually converging the beam. This avoids the formation of a high-heat focus inside the lens through abrupt focusing, and the working focus is only formed on the outer rear end, reducing heat accumulation and lens damage. At the same time, both the negative and positive lenses are made of materials with low thermal expansion coefficients. This not only suppresses thermal expansion deformation under high-power lasers, reducing thermal drift and focus shift, and ensuring the stability of optical-water coupling, but also ensures that the refractive index of each lens is consistent, avoiding the inward shift of the reflection focus caused by interface refraction distortion. An air buffer layer is set between adjacent lenses to block heat conduction and disperse the reflected light energy, preventing the formation of secondary focus in the gap between lenses after the reflected light paths of multiple lenses cross, and avoiding thermal interference between lenses. Finally, the coupling component 3 is set below the positive lens group 2. It can receive the converged beam and couple it with the high-pressure water jet to form a water-guided laser beam, realizing total internal reflection transmission of the laser in the water flow. This setup effectively solves the problems of easy heat damage to lenses, easy focus drift, and poor optical-water coupling stability in high-power laser processing, achieving precision processing effects with low deformation, low loss, and high coaxiality.

[0042] Optionally, the absolute value of the radius of curvature of the incident surface of the negative lens is smaller than the absolute value of the radius of curvature of the exit surface of the negative lens, and the absolute value of the radius of curvature of the incident surface of the positive lens is smaller than the absolute value of the radius of curvature of the exit surface of the positive lens.

[0043] Specifically, the absolute value of the radius of curvature of the incident surface of the negative lens can be 21.54 mm or 20 mm, and the absolute value of the radius of curvature of the exit surface can be 32.5 mm or 30 mm; the absolute value of the radius of curvature of the incident surface of the positive lens can be 11.17 mm or 21.84 mm, and the absolute value of the radius of curvature of the exit surface can be 22.81 mm or 71.09 mm.

[0044] In this optional embodiment, the absolute value of the radius of curvature of the incident surface of the negative lens is set to be smaller than the absolute value of the radius of curvature of the exit surface, while the absolute value of the radius of curvature of the incident surface of the positive lens is smaller than the absolute value of the radius of curvature of the exit surface. This setting can realize the asymmetric curvature structure of the negative lens and the positive lens respectively. Through the gradient of the radius of curvature, which is smaller at the front and larger at the back, the converging ability of the reflected light on each surface is deliberately weakened, so that both the negative lens and the positive lens can gradually deflect the laser beam, avoiding the generation of strong reflection focus and aberrations by the sharp refraction of light, so that the reflection focus can only fall outside the lens group. On this basis, the asymmetric curvature structure of the negative lens can also enhance the divergence effect and generate negative spherical aberration, which cancels out the positive spherical aberration of the positive lens and improves the beam quality. The asymmetric curvature structure of the positive lens can also further realize the smooth convergence, so that the beam gradually converges and does not form a solid focus inside the lens. At the same time, all the reflection focus on the surface of each lens falls outside the objective lens group, avoiding the burning of the lens by the reflected energy. This configuration allows the positive and negative lenses to work together to achieve the effects of no internal high-heat focal points in the optical path, regular beam shape, and low transmission loss, thus solving the problems of reflection ablation, large spherical aberration, and low coupling efficiency caused by unreasonable curvature design of traditional lenses.

[0045] Optionally, the thickness of each lens is configured to be calculated using the following formula, and the size of the air buffer layer is 2-8 mm: , in, For minimum thickness, and , Let be the radius of curvature of the incident surface of the lens. For lens thickness, For the maximum thickness, and , Let be the refractive index of the lens.

[0046] Specifically, minimum thickness It can be 10.77mm or 10mm; maximum thickness It can be 15.6mm or 16mm; lens refractive index It can be 1.458 or 1.46; the air buffer layer size can be 2mm, 4mm, 5mm or 8mm.

[0047] In this optional embodiment, the air buffer layer is set to 2-8mm, and the thickness of each lens is set to satisfy the formula. With this setting, in the formula In this approach, the center thickness of the lens can be determined based on its curvature and refractive index, avoiding insufficient structural strength due to excessive thinness and exacerbating laser absorption heating and thermal deformation problems due to excessive thickness. Furthermore, the thickness can be adaptively matched based on the radius of curvature to ensure lens surface accuracy and optical stability. Introducing the lens refractive index allows for thickness calculations to better align with the characteristics of materials with low thermal expansion. Based on this, and The near-field focusing critical distance of the reflected light in each lens is set at 2-8mm, which is greater than the near-field focusing critical distance. This utilizes the air optical path to increase the propagation distance of the reflected light, causing the reflected light to diverge continuously within the air buffer layer, preventing it from converging into a single point. This acts as an optical path isolation buffer, preventing the reflected light from the previous lens from focusing on the next lens, ensuring the stability of the optical path structure. Simultaneously, the air buffer layer effectively isolates heat. This configuration... In conjunction with the size setting of the air buffer layer, the laser processing lens combines the advantages of structural strength, low heat generation, and low reflection damage, solving the problems of easy breakage, large thermal deformation, and poor optical path stability caused by unreasonable lens thickness.

[0048] Optionally, the laser processing lens also includes a lens housing 4, which is a hollow structure with openings at both ends. The negative lens includes a negative meniscus lens, and the positive lens includes a first biconvex lens 21, a first positive meniscus lens 22, and a second positive meniscus lens 23. The negative meniscus lens, the first biconvex lens 21, the first positive meniscus lens 22, and the second positive meniscus lens 23 are arranged alternately in the lens housing 4 from top to bottom, and are all alternately fixed in the lens housing 4 by multiple pressure ring structures that are threadedly connected to the inner wall of the lens housing 4 through the outer wall.

[0049] Specifically, negative lenses include not only negative meniscus lenses but also plano-concave negative lenses; there are four lenses, correspondingly, such as... Figure 1 As shown, the pressure ring structure may include a first pressure ring 41, a second pressure ring 42, a third pressure ring 43, and a fourth pressure ring 44; In this optional embodiment, such as Figure 1As shown, a lens housing 4 with openings at both ends and a hollow structure is also provided. The negative meniscus lens (negative lens) and the first biconvex lens 21, first positive meniscus lens 22, and second positive meniscus lens 23 (positive lens) are arranged alternately from top to bottom on the lens housing 4. Each lens is alternately fixed by a pressure ring structure connected by threads on the outer wall. This arrangement not only provides protection through the lens housing 4, ensuring stable coaxiality and axial spacing of the lenses and preventing lens displacement caused by processing vibration, but also forms a stable optical path combination of negative in front and positive in back, realizing a beam shaping process of divergence and gradual convergence. On this basis, the negative meniscus lens is responsible for initial divergence and beam expansion and outward shifting of the reflection focus. The biconvex lens 21, first positive meniscus lens 22, and second positive meniscus lens 23 converge the beam step by step, so that the reflection focus falls entirely outside the lens group, eliminating internal heat damage. With this arrangement, the lens housing 4 and the pressure ring structure cooperate to achieve precise and controllable lens spacing, high overall coaxiality, and strong structural rigidity, effectively solving the problems of easy eccentricity, unstable spacing, and loosening and drifting after long-term use when assembling multiple lenses.

[0050] Optionally, the coupling assembly 3 includes a window 31 and a nozzle 32. The window 31 is placed flat below the lens housing 4 and corresponds to the lower opening end of the lens housing 4. The nozzle 32 is installed below the window 31, and a cavity structure 33 is formed between the window 31 and the nozzle 32. A water inlet 331 is provided on one side of the cavity structure 33. The nozzle 32 is a hollow structure with openings at the top and bottom, and the central axis of the opening coincides with the extension line of the incident laser, so as to form an outlet 321 at the upper opening end for the coupled laser beam to pass through. The inner diameter of the nozzle 32 gradually decreases from top to bottom.

[0051] Specifically, the window 31 can be an ultraviolet fused silica window or an optical-grade sapphire window; the inner diameter of the nozzle 32 can gradually change to a conical convergence or a stepped contraction; the diameter of the outlet 321 can be 40μm, 50μm or 60μm.

[0052] In this optional embodiment, such as Figure 1As shown, a coupling assembly 3 is formed by a window 31, a nozzle 32, and a cavity structure 33. The window 31 can close the lower opening of the lens housing 4, serving to seal the optical path, isolate the water path from the optical path, and ensure vertical transmission of the laser. The nozzle 32 is located below the window 31, forming a cavity structure 33 between them. A water inlet 331 is provided on one side, allowing high-pressure pure water to be introduced to form a uniform and continuous water layer, providing a medium for total internal reflection of the laser. At the same time, the nozzle 32 is a hollow structure with openings at the top and bottom, and its central axis coincides with the laser, ensuring coaxial output of the laser and water beam. Furthermore, the inner diameter of the nozzle 32 gradually decreases from top to bottom, thereby converging and shaping the water flow to form a micro water beam with a stable diameter and high straightness, confining the laser within the water beam for transmission. With this configuration, the window 31, cavity structure 33, and nozzle 32 work together to achieve stable water layer formation, low-loss laser coupling, and regular water beam output, effectively solving the problems of easy eccentricity, unstable water beam, severe light leakage, and low coupling efficiency in optical-water coupling.

[0053] For example, the negative meniscus lens can have an incident surface radius of curvature of -21.54 mm, an exit surface radius of curvature of -32.5 mm, a refractive index of 1.458, an Abbe number of 67.821, and a center thickness of 6 mm. The first biconvex lens 21 can have an incident surface radius of curvature of 38.87 mm, an exit surface radius of curvature of -60.77 mm, a refractive index of 1.458, an Abbe number of 67.821, and a center thickness of 5 mm. The first positive meniscus lens 22 can have an incident surface radius of curvature of 21.84 mm, an exit surface radius of curvature of 71.09 mm, a refractive index of 1.458, an Abbe number of 67.821, and a center thickness of 6 mm. The second positive meniscus lens 23 has an incident surface radius of curvature of 11.17 mm and an exit surface radius of curvature of 22.81 mm. Its refractive index is 1.458, its Abbe number is 67.821, and its center thickness is 6 mm. The distance between the exit surface of the negative meniscus lens and the incident surface of the first biconvex lens 21 is 2 mm; the distance between the exit surface of the first biconvex lens 21 and the incident surface of the first positive meniscus lens 22 is 5 mm; and the distance between the exit surface of the first positive meniscus lens 22 and the incident surface of the second positive meniscus lens 23 is 4 mm.

[0054] It should be noted that the lens housing 4 may also have a first protrusion and a second protrusion inside, such as... Figure 1As shown, the first pressure ring 41 may have an external thread, which can engage with the internal thread of the lens housing 4 to fix the negative meniscus lens inside the lens housing 4; the second pressure ring 42 may be disposed between the negative meniscus lens and the first biconvex lens 21, and is used to fix or adjust the distance between the negative meniscus lens and the first biconvex lens 21; the third pressure ring 43 may be disposed between the first biconvex lens 21 and the first positive meniscus lens 8, and is used to fix or adjust the distance between the biconvex lens 7 and the first positive meniscus lens 22, and can press the first positive meniscus lens 22 tightly fixed on the first boss; the fourth pressure ring 44 may have an external thread, which can engage with the internal thread of the lens housing 4 to fix the second positive meniscus lens 23 on the second boss.

[0055] Secondly, an embodiment of the present invention provides a processing system for a laser processing lens application, comprising a motion control module 5, a laser transmission module 6, a water jet coupling module 7, and a laser processing lens as described in any one of claims 1 to 5. The laser processing lens is mounted below the laser output port of the laser transmission module 6 and is drivenly connected to the motion control module 5. The water jet coupling module 7 is connected to the coupling component 3 of the laser processing lens. The motion control module 5 is configured to clamp and move the workpiece to be processed and is communicatively connected to both the laser transmission module 6 and the water jet coupling module 7. The motion control module 5 is used to: drive the water jet coupling module 7 to open and transmit high-pressure pure water to the coupling component. Component 3 simultaneously adjusts the supply parameters of high-pressure pure water to a preset supply range; determines whether the water flow state at coupling component 3 is in a preset state; if so, drives laser transmission module 6 to turn on, transmitting laser to the laser processing lens; adjusts the supply parameters of high-pressure pure water and the output parameters of the laser to adapt the laser to the water jet channel, completing coupling with the water jet; when the workpiece to be processed is clamped and fixed, drives the laser processing lens to move and complete focusing, drives the workpiece to move along the preset processing trajectory for processing; when the workpiece to be processed is completed, drives laser transmission module 6 to turn off, waits for a preset time, drives water jet coupling module 7 to turn off, and summarizes the processing condition data to the storage database.

[0056] Specifically, the high-pressure pure water supply parameters can be a water pressure of 0.5-2.0 MPa and a flow rate of 0.2-0.8 L / min; the preset coupling efficiency can be 95%, 96%, or 98%; and the preset waiting time to shut off can be 3s, 5s, or 10s.

[0057] In this embodiment, as Figure 2As shown, a processing system for laser processing lenses is constructed by setting up a motion control module 5, a laser transmission module 6, a water jet coupling module 7, and the aforementioned laser processing lens. Before processing, the motion control module 5 first drives the water jet coupling module 7 to open and adjust its parameters to a preset range, thereby establishing a stable water flow and a uniform water layer, providing preconditions for laser coupling. Next, the motion control module 5 determines that the water flow has reached a preset state and then activates the laser transmission module 6, thereby emitting the laser only after the water flow has stabilized, avoiding damage to the lens caused by laser idling. Finally, the motion control module 5 adjusts the water pressure and laser output parameters to adapt the laser to the water jet channel. This achieves efficient optical-water coupling and maintains high coupling efficiency. Subsequently, after the workpiece is clamped, the motion control module 5 can drive the lens to focus and move the workpiece along the trajectory for processing, ensuring that the focus falls precisely on the processing surface. Finally, after processing is completed, the motion control module 5 can first turn off the laser transmission module 6 and then delay turning off the water jet coupling module 7, thereby realizing the process of stopping energy input first and then stopping water flow, avoiding residual heat damage and water path residual interference. With this setting, the modules work together to achieve fully automatic water flow voltage stabilization, laser start-up and shutdown, coupling matching, trajectory processing, and data aggregation, solving the problems of cumbersome manual adjustment, unstable coupling, low processing accuracy, and discontinuous process.

[0058] Optionally, the water jet coupling module 7 includes a water storage tank, a pure water filter, a high-pressure water pump, a water delivery pipeline, and a pressure and flow sensor. The pure water filter is installed on the water storage tank and is connected to the coupling component 3 of the laser processing lens through the high-pressure water pump and the delivery pipeline. The pressure and flow sensor is installed inside the delivery pipeline. The motion control module 5 is communicatively connected to the pure water filter, the high-pressure water pump, and the pressure and flow sensor, and is used to: sequentially drive the pure water filter and the high-pressure water pump to start, collect the actual water pressure value of the delivery pipeline in real time through the pressure and flow sensor, and adjust the operating frequency of the high-pressure water pump so that the actual water pressure value is within the preset water pressure range.

[0059] Specifically, the pure water filter can be a multi-stage filter cartridge or a reverse osmosis pure water device; the preset water pressure range can be 0.5-1.0MPa or 1.0-2.0MPa; the frequency of the water pump can be 20-50Hz or 30-60Hz.

[0060] In this optional embodiment, a water jet coupling module 7 is composed of a water storage tank, a pure water filter, a high-pressure water pump, a water supply pipeline, and a pressure and flow sensor. The pure water filter purifies the raw water to remove impurities, preventing impurities from clogging the nozzle 31, scratching the window 32, and obstructing the light path. The high-pressure water pump supplies water to the coupling component 3 through the water supply pipeline, providing a stable pressure water source. Based on this, the pressure and flow sensor collects the actual water pressure in real time, and the motion control module 5 adjusts the water pump frequency to ensure the water pressure falls within a preset range, forming a closed-loop pressure stabilization control to ensure uniform water layer thickness and stable water jet shape within the cavity. This configuration, with the pure water filter, high-pressure water pump, pressure and flow sensor, and motion control module 5 working together, achieves pure water supply, closed-loop pressure stabilization, and rapid response adjustment, effectively solving the problems of decreased coupling efficiency and poor processing stability caused by large water pressure fluctuations, poor water quality, and uneven water layers.

[0061] Optionally, the laser transmission module 6 includes a laser emitter 61, a collimating lens group 62, and a reflecting lens assembly 63. The motion control module 5 includes a control element, a first power sensor, and a second power sensor. The laser emitter 61 is mounted above the collimating lens group 62, and the reflecting lens assembly 63 is mounted below the collimating lens group 62 and above the laser processing lens. The first power sensor is mounted between the reflecting lens assembly 63 and the laser processing lens, and the second power sensor is mounted below the outlet 321 of the coupling assembly 3. The control element is communicatively connected to the laser emitter 61, the first power sensor, and the second power sensor, and is used to: drive the laser emitter 61 to turn on, so as to emit laser light that is transmitted to the laser processing lens through the collimating lens group 62 and the reflecting lens assembly 63; and collect the incident laser power of the laser light entering the laser processing lens through the first power sensor; collect the emitted laser power of the laser light output through the outlet 321 through the second power sensor; and calculate the optical-water coupling efficiency based on the following formula: , in, For light-water coupling efficiency, The output laser power, The incident laser power is used to determine whether the optical-water coupling efficiency is within the preset coupling efficiency range in real time. If not, the supply parameters are adjusted. If the optical-water coupling efficiency is outside the preset coupling efficiency range after adjusting the supply parameters, the output power of the laser emitter 61 is adjusted synchronously until the optical-water coupling efficiency is within the preset coupling efficiency range.

[0062] Specifically, the laser emitter 61 can be a pulsed fiber laser or an ultraviolet laser; the preset coupling efficiency range can be 95%-100%; such as Figure 3As shown, the collimating lens group 62 consists of a third positive meniscus lens 621 and a second biconvex lens 622 that are coaxially spaced from top to bottom, and the reflecting lens assembly 63 consists of a first reflecting mirror 631 that is inclined below the second biconvex lens 622 and a second reflecting mirror 632 that is inclined above the laser processing lens.

[0063] In this optional embodiment, such as Figure 2 As shown, the laser transmitter 61, collimating lens group 62, and reflecting lens assembly 63 constitute the laser transmission module 6. Simultaneously, a control element, a first power sensor, and a second power sensor constitute the motion control module 5. The collimating lens group 62 shapes the laser beam into parallel light, and the reflecting lens assembly 63 deflects the light path before it enters the laser processing lens, ensuring coaxial incident beam. Based on this, the first power sensor collects the incident power, the second power sensor collects the output power, and the control element controls the motion via... The coupling efficiency is calculated, and the optical-water matching status is monitored in real time. This setup, when the coupling efficiency falls below a preset range, first adjusts the water pressure to change the water beam shape, then adjusts the laser power to compensate for energy loss, bringing the efficiency back to the acceptable range. Thus, through the coordinated operation of laser transmission, power detection, and closed-loop adjustment, high-quality beam transmission and real-time monitoring and dynamic correction of coupling efficiency are achieved, effectively solving problems such as focus drift, light leakage, energy attenuation, and unstable coupling efficiency.

[0064] It should be noted that the upper surface of the first reflector 631 can be coated with a high-reflectivity film, while the lower surface of the first reflector 631 may not be coated. It should be understood that the reflectivity of the upper surface coated with the high-reflectivity film can reach 99.9%. Based on this, when a laser beam propagates to the upper surface of the first reflector 631, it can be reflected by the upper surface, changing the propagation direction of the laser beam. Similarly, the lower surface of the second reflector 632 can be coated with a high-reflectivity film. When a laser beam is reflected by the first reflector 631 and propagates to the second reflector 632, it can be reflected by the lower surface of the second reflector 632, changing the propagation direction of the laser beam. The second reflector 632 and the first reflector 631 can be parallel. It should be understood that when the angle of the second reflector 632 is adjusted, the propagation direction of the laser beam reflected by the second reflector 632 will also be deflected. Therefore, before use, the angle of the second reflector 632 can be adjusted so that the focal point of the laser beam reflected by the second reflector 632 is at the same position as the center of the circular hole on the upper surface of the nozzle 32.

[0065] For example, with Figure 3 Taking the laser processing lens shown as an example, in the processing system where the laser processing lens is applied, when using such... Figure 1 The specific settings of the lenses or mirrors used in the laser processing lens shown are shown in Table 1: Table 1 Optical Lens Data Sheet Figure 4 Optical system point diagram of the processing system used for laser processing lenses employing the optical data in Table 1. (See Table 1 for example.) Figure 4 As shown, the root mean square radius of the diffuse spot is 1.425 μm, which is smaller than the radius of the Airy disk, 1.752 μm. This means that the optical system using this data forms a very small spot, indicating that the laser beam propagating into the water layer can couple well with the water jet to form a laser beam.

[0066] Figure 5 The modulation transfer function diagram of the optical system for the laser processing lens application using the optical data in Table 1. (See Table 1 for example.) Figure 5 As shown, the horizontal axis represents spatial frequency, and the vertical axis represents the optical transfer function (OTF) magnitude. At a spatial frequency of 700 Hz, the OTF magnitude essentially matches the diffraction limit, approaching ideal imaging. The optical transfer function (OTF) is a function that characterizes the relative changes in modulation and lateral phase shift during imaging, with spatial frequency as the variable.

[0067] Figure 6 A schematic diagram of the reflection focal points of each lens in a processing system using the optical data in Table 1 for laser processing lenses. (See table below.) Figure 6 As shown, 61 is a schematic diagram of the reflection focus formed when the laser beam propagates to the exit surface of the third positive meniscus lens; 62-1 is a schematic diagram of the reflection focus formed when the laser beam propagates to the incident surface of the second biconvex lens; 62-2 is a schematic diagram of the reflection focus formed when the laser beam propagates to the exit surface of the second biconvex lens; 63-1 is a schematic diagram of the reflection focus formed when the laser beam propagates to the incident surface of the negative meniscus lens; 63-2 is a schematic diagram of the reflection focus formed when the laser beam propagates to the exit surface of the negative meniscus lens; 64-1 is a schematic diagram of the reflection focus formed when the laser beam propagates to the incident surface of the first biconvex lens; 64-2 is a schematic diagram of the laser beam propagating to the incident surface of the first biconvex lens; A schematic diagram of the reflection focus formed when the laser beam propagates to the exit surface of the first biconvex lens; 65-1 is a schematic diagram of the reflection focus formed when the laser beam propagates to the incident surface of the first positive meniscus lens; 65-2 is a schematic diagram of the reflection focus formed when the laser beam propagates to the exit surface of the first positive meniscus lens; 66-1 is a schematic diagram of the reflection focus formed when the laser beam propagates to the incident surface of the second positive meniscus lens; 66-2 is a schematic diagram of the reflection focus formed when the laser beam propagates to the exit surface of the second positive meniscus lens; 67 is a schematic diagram of the reflection focus formed when the laser beam propagates to the window. It can be seen that the reflection focus is not on any of the lenses of the laser processing lens.

[0068] Figure 7 A schematic diagram of wavefront aberrations in the optical system of a laser processing lens application system using the optical data in Table 1. (See table below.) Figure 7 As shown, the optical path difference of the optical system is between 0.25 and +0.25 wavelengths, which is extremely small.

[0069] In traditional laser processing equipment, when a laser beam passes through a 150μm or 200μm fiber core, the diameter of the conventional nozzle is typically 60μm or 50μm. However, when using the processing system employing the laser processing lens provided in the above embodiment, under the same incident laser beam conditions, the focused spot diameter of the laser beam is 50μm. Therefore, the laser beam can be coupled into a smaller diameter nozzle 32, reducing the laser beam diameter to 40μm. Compared to a conventional nozzle emitting a laser beam with a diameter of 80μm, this significantly reduces the processing kerf width and effectively reduces material loss when applied to the surface processing of valuable materials. Furthermore, because the nozzle 32 has a smaller diameter, the laser beam diameter is also reduced, thereby increasing the energy density in the laser beam and effectively shortening the processing time.

[0070] Optionally, the motion control module 5 also includes a three-axis precision motion platform and a suction clamping fixture, both of which are communicatively connected to the control element. The suction clamping fixture is mounted on the reference positioning surface of the three-axis precision motion platform. The control element is also used to: drive the suction clamping fixture to clamp and suction the workpiece when it is placed on the reference positioning surface, and simultaneously establish a workpiece machining contour motion reference based on the imported initial preset trajectory; calculate the single-axis real-time positioning error compensation amount of the three-axis precision motion platform according to the following formula, and generate a preset machining trajectory based on the single-axis real-time positioning error compensation amount and the workpiece machining contour motion reference. , in, This is the compensation amount for real-time positioning error on a single axis. The fitting coefficients for the error attenuation amplitude are... It is a time constant. The error decay time constant, The inherent static deviation fitting coefficients, This refers to the duration of continuous processing.

[0071] Specifically, the error attenuation amplitude fitting coefficient can be 0.005mm or 0.01mm; the time constant can be 100s or 200s; the inherent static deviation fitting coefficient can be 0.002mm or 0.003mm; and the continuous processing time can be 10min, 30min or 60min.

[0072] In this optional embodiment, the motion control module 5 is further equipped with a three-axis precision motion platform and an adsorption clamping fixture. The adsorption clamping fixture flattens and fixes the workpiece to prevent slippage during processing. The three-axis precision motion platform moves the workpiece according to a preset processing trajectory for processing. At the same time, the motion control module 5 imports the trajectory to establish a processing benchmark and processes the workpiece according to the preset processing trajectory. The calculation of single-axis real-time positioning error compensation amount compensates for positioning errors caused by platform mechanical backlash, temperature rise drift, and motion lag. This compensation amount can be superimposed on the original trajectory to correct platform motion deviations. This setup is suitable for adsorption clamping fixtures, three-axis precision motion platforms, and [other types of equipment]. The two mechanisms work together to achieve stable workpiece clamping, accurate trajectory correction, and real-time compensation for positioning errors, effectively solving the problems of inaccurate mechanical motion positioning, trajectory distortion, and long-term machining accuracy decay.

[0073] Optionally, the motion control module 5 also includes an electric lifter, which is located on one side of the three-axis precision motion platform and is connected to the laser processing lens drive. The control element is communicatively connected to the electric lifter and is also used to: based on the position height of the processing surface of the workpiece, and according to the focal length parameter of the laser processing lens, drive the laser processing lens to lift and lower as a whole through the electric lifter, and adjust the distance of the laser processing lens relative to the processing surface to adapt to the focal length parameter.

[0074] Specifically, the electric lifter's adjustable stroke can be 5-20mm or 10-30mm; the focal length parameter can be 10mm, 15mm or 20mm; and the height difference of the workpiece's machined surface must include at least 0.1mm, 0.2mm or 0.5mm.

[0075] In this optional embodiment, the motion control module 5 is further equipped with an electric lifter, which is connected to the laser processing lens drive. The control element can drive the lifter to raise and lower the entire lens according to the height of the workpiece processing surface and the lens focal length parameters, thereby precisely adjusting the distance between the lens and the workpiece, ensuring that the laser focus is stably placed on the processing surface, and avoiding defects such as incomplete cutting, large taper, and wide heat-affected zone caused by defocus. With this configuration, the electric lifter, the three-axis precision motion platform, the control element, and the laser processing lens work together to achieve automatic focusing, adaptive matching of the focus position, and consistent processing depth, solving the problems of low efficiency, poor accuracy, and mismatch between the focus and the workpiece surface in manual focusing.

[0076] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., 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 laser processing lens, characterized in that, It includes a negative lens group (1), a positive lens group (2) and a coupling component (3); the negative lens group (1) and the positive lens group (2) are arranged coaxially at intervals, and the optical axis coincides with the extension line of the incident laser that is transmitted vertically from top to bottom; The total optical power of the negative lens group (1) is negative and includes at least one negative lens; the positive lens group (2) includes multiple positive lenses and is arranged at intervals along the extension line of the incident laser; the optical power of the positive lens is positive and is less than a preset weak light power value; both the positive lens and the negative lens are made of a preset material, and the thermal expansion coefficient of the preset material is lower than a preset low thermal expansion coefficient; an air buffer layer is provided between two adjacent lenses; the coupling component (3) is located below the positive lens group (2) and is configured to receive the converging beam output by the positive lens group (2) and couple with the high-pressure water jet to form a laser beam output.

2. The laser processing lens as described in claim 1, characterized in that, The absolute value of the incident surface radius of curvature of the negative lens is less than the absolute value of the exit surface radius of curvature of the negative lens, and the absolute value of the incident surface radius of curvature of the positive lens is less than the absolute value of the exit surface radius of curvature of the positive lens.

3. The laser processing lens as described in claim 2, characterized in that, The thickness of each lens is configured to be calculated using the following formula, and the size of the air buffer layer is 2-8 mm: ， Among them, the For minimum thickness, and The The radius of curvature of the incident surface of the lens is given by the following formula: For the lens thickness, the For the maximum thickness, and The The refractive index of the lens is denoted as .

4. The laser processing lens as described in claim 1, characterized in that, It also includes a lens housing (4), which is a hollow structure with openings at both ends. The negative lens includes a negative meniscus lens, and the positive lens includes a first biconvex lens (21), a first positive meniscus lens (22), and a second positive meniscus lens (23). The negative meniscus lens, the first biconvex lens (21), the first positive meniscus lens (22), and the second positive meniscus lens (23) are arranged in the lens housing (4) from top to bottom at intervals, and are all alternately fixed in the lens housing (4) by multiple pressure ring structures that are threaded to the inner wall of the lens housing (4) through the outer wall.

5. The laser processing lens as described in claim 4, characterized in that, The coupling component (3) includes a window (31) and a nozzle (32). The window (31) is placed flat below the lens housing (4) and corresponds to the lower opening end of the lens housing (4). The nozzle (32) is installed below the window (31) and a cavity structure (33) is formed between the window (31) and the nozzle (32). A water inlet (331) is provided on one side of the cavity structure (33). The nozzle (32) is a hollow structure with openings at the top and bottom, and the central axis of the opening coincides with the extension line of the incident laser, so as to form an outlet (321) at the upper opening end for the coupled laser beam to pass through. The inner diameter of the nozzle (32) gradually decreases from top to bottom.

6. A processing system for laser-processed lenses, characterized in that, The system includes a motion control module (5), a laser transmission module (6), a water jet coupling module (7), and a laser processing lens as described in any one of claims 1 to 5. The laser processing lens is mounted below the laser output port of the laser transmission module (6) and is driven and connected to the motion control module (5). The water jet coupling module (7) is connected to the coupling component (3) of the laser processing lens. The motion control module (5) is configured to clamp and move the workpiece to be processed and is communicatively connected to the laser transmission module (6) and the water jet coupling module (7), respectively. The motion control module (5) is used for: Drive the water jet coupling module (7) to turn on, transmit high-pressure pure water to the coupling component (3), and adjust the supply parameters of the high-pressure pure water to the preset supply range at the same time; Determine whether the water flow state at the coupling component (3) is a preset state. If so, drive the laser transmission module (6) to turn on and transmit the laser to the laser processing lens. Adjust the supply parameters of the high-pressure pure water and the output parameters of the laser to adapt the laser to the water beam channel and complete the coupling with the water beam; When the workpiece is clamped and fixed, the laser processing lens is driven to move and focus, and the workpiece is driven to move along the preset processing trajectory for processing; After the workpiece is processed, the laser transmission module (6) is turned off. After waiting for a preset time, the water jet coupling module (7) is turned off, and the processing condition data is summarized into the storage database.

7. The processing system for laser processing lenses as described in claim 6, characterized in that, The water jet coupling module (7) includes a water storage tank, a pure water filter, a high-pressure water pump, a water delivery pipeline, and a pressure and flow sensor. The pure water filter is installed on the water storage tank and is connected to the coupling assembly (3) of the laser processing lens through the high-pressure water pump and the delivery pipeline. The pressure and flow sensor is installed inside the delivery pipeline. The motion control module (5) is communicatively connected to the pure water filter, the high-pressure water pump, and the pressure and flow sensor, and is used for: The pure water filter and the high-pressure water pump are turned on in sequence. The actual water pressure value of the delivery pipeline is collected in real time by the pressure and flow sensor. The operating frequency of the high-pressure water pump is adjusted so that the actual water pressure value is within the preset water pressure range.

8. The processing system for laser processing lenses as described in claim 7, characterized in that, The laser transmission module (6) includes a laser emitter (61), a collimating lens group (62), and a reflecting lens assembly (63). The motion control module (5) includes a control element, a first power sensor, and a second power sensor. The laser emitter (61) is mounted above the collimating lens group (62), and the reflecting lens assembly (63) is mounted below the collimating lens group (62) and above the laser processing lens. The first power sensor is mounted between the reflecting lens assembly (63) and the laser processing lens. The second power sensor is mounted below the outlet (321) of the coupling assembly (3). The control element is communicatively connected to the laser emitter (61), the first power sensor, and the second power sensor, and is used for: The laser emitter (61) is driven to turn on, so as to emit laser light that is transmitted to the laser processing lens through the collimating lens group (62) and the reflecting lens assembly (63), and the incident laser power of the laser light entering the laser processing lens is collected by the first power sensor. The emitted laser power of the laser output through the outlet (321) is collected by the second power sensor, and the optical-water coupling efficiency is calculated based on the following formula: ， Among them, the The light-water coupling efficiency is the stated value. The emitted laser power, the The incident laser power; In real time, determine whether the optical-water coupling efficiency is within the preset coupling efficiency range. If not, adjust the supply parameters. If the optical-water coupling efficiency is outside the preset coupling efficiency range after adjusting the supply parameters, synchronously adjust the output power of the laser emitter (61) until the optical-water coupling efficiency is within the preset coupling efficiency range.

9. The processing system for laser processing lenses as described in claim 8, characterized in that, The motion control module (5) also includes a three-axis precision motion platform and an adsorption clamping fixture, both of which are communicatively connected to the control element. The adsorption clamping fixture is mounted on the reference positioning surface of the three-axis precision motion platform. The control element is also used for: When the workpiece is placed on the reference positioning surface, the adsorption clamping fixture is driven to clamp and adsorb the workpiece, and at the same time, the workpiece processing contour motion reference is established according to the imported initial preset trajectory. The single-axis real-time positioning error compensation amount of the three-axis precision motion platform is calculated according to the following formula, and the preset machining trajectory is generated based on the single-axis real-time positioning error compensation amount and the workpiece machining contour motion reference: ， Among them, the The single-axis real-time positioning error compensation amount, the The error attenuation amplitude fitting coefficients, the The time constant, the The error decay time constant, the The inherent static deviation fitting coefficients, the This refers to the duration of continuous processing.

10. The processing system for laser processing lenses as described in claim 9, characterized in that, The motion control module (5) also includes an electric lift, which is located on one side of the three-axis precision motion platform and is connected to the laser processing lens drive. The control element is communicatively connected to the electric lift and is also used for: Based on the position and height of the processing surface of the workpiece, and according to the focal length parameter of the laser processing lens, the laser processing lens is driven to rise and fall as a whole by the electric lifting device, adjusting the distance of the laser processing lens relative to the processing surface to match the focal length parameter.

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