Liquid guide laser processing device based on double-beam phase adjustment

Abstract

The utility model discloses a liquid guide laser processing device based on double-beam phase adjustment, belongs to the technical field of laser processing, and aims to reduce the width of a laser beam. The device comprises a laser light source, a first polarization state modulator, a beam splitter, a spatial light modulator, a second polarization state modulator, a polarization beam combiner and a coupler. A laser light source emits linearly polarized light, the linearly polarized light is converted into circularly polarized light through a first polarization state modulator, then the circularly polarized light is separated into first linearly polarized light and second linearly polarized light through a light beam separator, and on a second linearly polarized light transmission light path, a spatial light modulator adjusts the marginal region phase of the circularly polarized light to enable the marginal region phase to differ from the marginal region phase of the first linearly polarized light by a half cycle. And the second polarization state modulator adjusts the polarization direction to be the same as that of the first linearly polarized light, the polarization beam combiner combines the two beams of light, the coupler couples the combined laser beams to the liquid jet flow, and the liquid jet flow acts on the workpiece to be machined, so that optimization of the diameter of the laser beams is achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of laser processing, and particularly relates to a liquid-guided laser processing device based on double-beam phase adjustment. BACKGROUND

[0002] Laser processing is widely used in modern manufacturing industry due to its high precision, non-contact and small heat-affected zone. From fine micro-processing of electronic devices to complex shaping of aerospace parts, laser processing technology continues to drive manufacturing towards high precision and high efficiency. However, as the requirements for processing precision and quality continue to rise in various industries, traditional laser processing technology has exposed many limitations in processing high-hardness, high-brittle and complex-shaped materials.

[0003] In the traditional laser processing process, due to the high concentration of laser energy, it is easy to produce a high temperature gradient in the processing area, which causes thermal stress damage, micro-cracks and increased surface roughness of the material. Especially for some materials that are sensitive to heat, such as optical crystals, semiconductor materials, etc., these thermal damage defects seriously affect the product performance and service life.

[0004] To overcome the above problems, liquid-guided laser processing technology has emerged. This technology couples the laser beam into a liquid jet, uses the conduction and diffusion of laser energy by the liquid to effectively reduce the temperature peak of the processing area and reduce thermal stress damage. At the same time, the liquid jet can flush the debris generated during processing to improve the quality of the processed surface. However, the existing liquid-guided laser processing device has deficiencies in beam width regulation, and the emitted laser beam width is large, which cannot meet the user's demand. CONTENT OF THE INVENTION

[0005] Therefore, the application provides a liquid-guided laser processing device based on double-beam phase adjustment, which mainly aims to reduce the width of the laser beam.

[0006] To achieve the above purpose, the application mainly provides the following technical solutions:

[0007] In one aspect of the application, a liquid-guided laser processing device based on double-beam phase adjustment is provided, which comprises:

[0008] a laser light source, a first polarization state modulator, a beam splitter, a second polarization state modulator, a spatial light modulator, a polarization beam combiner and a coupler;

[0009] The first polarization modulator is located on the output optical path of the laser source and is used to convert the linearly polarized light emitted by the laser source into circularly polarized light. The beam splitter is disposed downstream of the first polarization modulator along the propagation direction of the circularly polarized light and is used to separate the circularly polarized light into first linearly polarized light and second linearly polarized light. The second polarization modulator and the spatial light modulator are located on the transmission optical path of the second linearly polarized light and between the beam splitter and the polarization combiner. The second polarization modulator is used to adjust the polarization direction of the second linearly polarized light to be the same as the polarization direction of the first linearly polarized light, and the spatial light modulator is used to adjust the phase of the edge region of the second linearly polarized light to be half a period different from the phase of the edge region of the first linearly polarized light. The polarization combiner is used to receive and combine the first linearly polarized light output by the beam splitter and the second linearly polarized light modulated by the second polarization modulator and the spatial light modulator. The coupler is located on the output optical path of the polarization combiner and is used to couple the laser beam combined by the polarization combiner into a liquid jet, and the liquid jet acts on the workpiece.

[0010] Optionally, the liquid-guided laser processing apparatus based on dual-beam phase adjustment further includes:

[0011] Beam pointing adjustment lens group;

[0012] The beam pointing adjustment mirror group includes at least a first reflector, a second reflector, a third reflector, and a fourth reflector;

[0013] The first and second mirrors are located between the first polarization modulator and the beam splitter;

[0014] The third reflecting mirror is located on the transmission optical path of the first linearly polarized light and is between the beam splitter and the polarization combiner;

[0015] The fourth reflector is located on the transmission optical path of the second linearly polarized light, and between the spatial light modulator and the polarization combiner.

[0016] Optionally, the liquid-guided laser processing apparatus based on dual-beam phase adjustment further includes:

[0017] Condenser lens assembly;

[0018] The condenser lens assembly includes at least a first condenser lens;

[0019] The first condenser lens is located between the polarization combiner and the coupler.

[0020] Optionally, the liquid-guided laser processing apparatus based on dual-beam phase adjustment further includes:

[0021] Liquid supply system;

[0022] The coupler has a jet hole at its bottom and a coupling cavity inside the coupler. The coupling cavity is connected to the jet hole and the liquid supply system. The liquid supply system is used to deliver a high-pressure liquid medium into the coupling cavity. The high-pressure liquid medium is configured to exit through the jet hole to form the liquid jet.

[0023] Optionally, the liquid-guided laser processing apparatus based on dual-beam phase adjustment further includes:

[0024] Heat sink block;

[0025] The polarization combiner has a main exit surface and a side exit surface, the main exit surface being disposed toward the coupler and the side exit surface being disposed toward the heat sink.

[0026] Optionally, the liquid-guided laser processing apparatus based on dual-beam phase adjustment further includes:

[0027] Image acquisition equipment;

[0028] The image acquisition device is located on the side of the coupler away from the workpiece to be processed, and the detection end of the image acquisition module is positioned facing the coupler.

[0029] Optionally, the liquid-guided laser processing apparatus based on dual-beam phase adjustment further includes:

[0030] Coupling adjustment mechanism;

[0031] The coupling adjustment mechanism includes at least a first motion component, a second motion component, and a third motion component;

[0032] The first motion component is connected to the spatial light modulator; the second motion component is connected to the fourth reflector; and the third motion component is connected to the coupler.

[0033] By employing the above technical solution, this application has at least the following beneficial effects:

[0034] The liquid-guided laser processing apparatus based on dual-beam phase adjustment provided in the embodiments of this application, by setting up components such as a first polarization modulator, a beam splitter, a second polarization modulator, a spatial light modulator, and a polarization beam combiner, first converts linearly polarized light into circularly polarized light, then separates the circularly polarized light into first linearly polarized light and second linearly polarized light. Next, the polarization direction of the second linearly polarized light is adjusted by the second polarization modulator, and the phase of the edge region of the second linearly polarized light is adjusted by the spatial light modulator to a phase difference of half a cycle from the phase of the edge region of the first linearly polarized light. Finally, the first and second linearly polarized lights are combined by the polarization beam combiner, thus achieving control over the laser beam width. Specifically, when the first and second linearly polarized lights are combined in the polarization beam combiner, because the phase difference between the edge regions of the first and second linearly polarized lights is half a cycle, interference occurs in the encounter region. During the interference process, the peaks and troughs of the edge regions of the first and second linearly polarized lights superimpose and cancel each other out, forming a narrower laser beam. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of a liquid-guided laser processing apparatus based on dual-beam phase adjustment, according to an optional embodiment of this application.

[0036] Figure 2 This is the energy distribution diagram of the light spot without phase modulation;

[0037] Figure 3 For application Figure 1 The device shown presents a spot energy distribution diagram formed after phase modulation.

[0038] Figure 4 To form Figure 3 The schematic diagram of the energy distribution of the light spot shown;

[0039] Figure 5 For application Figure 1 The energy distribution diagram of another light spot formed after phase modulation of the device shown;

[0040] Figure 6 This is a flowchart of an optional embodiment of a liquid-guided laser processing method based on dual-beam phase adjustment, which is a schematic diagram of the present application.

[0041] The reference numerals in the attached figures are as follows:

[0042] 1. Laser source; 2. First polarization modulator; 3. Beam splitter; 31. First linearly polarized light; 32. Second linearly polarized light; 4. Second polarization modulator; 5. Spatial light modulator; 6. Polarization beam combiner; 7. Coupler; 8. Liquid jet; 9. Workpiece to be processed; 10. First reflector; 11. Second reflector; 12. Third reflector; 13. Fourth reflector; 14. First condenser lens; 15. Liquid supply system; 16. Heat sink; 17. Image acquisition device. Detailed Implementation

[0043] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0044] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0045] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0046] The preferred embodiments of this application are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit this application.

[0047] See also Figures 1 to 5As shown, according to an embodiment of this application, a liquid-guided laser processing apparatus based on dual-beam phase adjustment is provided, comprising: a laser source 1, a first polarization modulator 2, a beam splitter 3, a second polarization modulator 4, a spatial light modulator 5, a polarization beam combiner 6, and a coupler 7; the first polarization modulator 2 is located on the output optical path of the laser source 1 and is used to convert the linearly polarized light emitted by the laser source 1 into circularly polarized light; the beam splitter 3 is disposed downstream of the first polarization modulator 2 along the propagation direction of the circularly polarized light and is used to separate the circularly polarized light into a first linearly polarized light 31 and a second linearly polarized light 32; the second polarization modulator 4 and the spatial light modulator 5 are located on the transmission optical path of the second linearly polarized light 32, and are coupled in the optical path of the laser source 1. Between beam splitter 3 and polarization combiner 6, second polarization modulator 4 is used to adjust the polarization direction of second linearly polarized light 32 to be the same as that of first linearly polarized light 31, and spatial light modulator 5 is used to adjust the phase of the edge region of second linearly polarized light 32 to be half a cycle different from the phase of the edge region of first linearly polarized light 31; polarization combiner 6 is used to receive and combine the first linearly polarized light 31 output by beam splitter 3 and the second linearly polarized light 32 modulated by second polarization modulator 4 and spatial light modulator 5; coupler 7 is located on the output optical path of polarization combiner 6, and coupler 7 is used to couple the laser beam after being combined by polarization combiner 6 into liquid jet 8, and liquid jet 8 acts on workpiece 9.

[0048] In this embodiment, by setting up components such as a first polarization modulator 2, a beam splitter 3, a second polarization modulator 4, a spatial light modulator 5, and a polarization beam combiner 6, linearly polarized light is first converted into circularly polarized light. Then, the circularly polarized light is separated into a first linearly polarized light 31 and a second linearly polarized light 32. Next, the polarization direction of the second linearly polarized light 32 is adjusted by the second polarization modulator 4, and the phase of the edge region of the second linearly polarized light 32 is adjusted by the spatial light modulator 5 to be half a period different from the phase of the edge region of the first linearly polarized light 31. Finally, the first linearly polarized light 31 and the second linearly polarized light 32 are combined by the polarization beam combiner 6, thus achieving control over the laser beam width. Specifically, when the first linearly polarized light 31 and the second linearly polarized light 32 are combined in the polarization beam combiner 6, because the phase of the edge region of the first linearly polarized light 31 differs from the phase of the edge region of the second linearly polarized light 32 by half a period, interference occurs in the encounter region. During the interference process, the peaks and troughs of the edge regions of the first linearly polarized light 31 and the second linearly polarized light 32 superimpose and cancel each other out, forming a narrower laser beam.

[0049] Among them, the laser source 1 can be a laser, which can emit horizontally polarized light or vertically polarized light with wavelengths in the range of 400nm to 1200nm, providing initial laser energy for the entire processing device.

[0050] The first polarization modulator 2 can be a quarter-wave plate. The quarter-wave plate can modulate the electric field vector of the linearly polarized light (such as horizontally polarized light or vertically polarized light) emitted by the laser source 1, so that the linearly polarized light rotates in a plane perpendicular to the propagation direction to form circularly polarized light.

[0051] Specifically, in practical applications, the fast axis of the quarter-wave plate can be adjusted to be 45° to the polarization direction of the horizontally or vertically polarized light emitted by the laser, thereby converting the horizontally or vertically polarized light into circularly polarized light. The resulting circularly polarized light then reaches beam splitter 3. Beam splitter 3 can separate the circularly polarized light into two beams of different polarizations: a first linearly polarized beam 31 and a second linearly polarized beam 32. In this way, the goal of dual-beam output is successfully achieved, providing a foundation for further adjustments to the polarization direction and phase of these two beams to control the laser beam width.

[0052] Among them, the beam splitter 3 can be a polarizing beam splitter. The polarizing beam splitter can use its selective effect on light with different polarization states to separate circularly polarized light into a first linearly polarized light 31 and a second linearly polarized light 32 with different polarization directions, which is equivalent to splitting a beam of light into two beams of light with specific polarization characteristics.

[0053] Specifically, the polarization directions of the first linearly polarized light 31 and the second linearly polarized light 32 are perpendicular to each other, and their propagation directions are also perpendicular to each other. Therefore, the polarization directions and phase states of the first linearly polarized light 31 and the second linearly polarized light 32 can be adjusted subsequently to achieve a laser beam that meets the user's requirements after merging. In this embodiment, the first linearly polarized light 31 can directly enter the polarization combiner 6, and the polarization direction and phase state of the second linearly polarized light 32 are only adjusted along its propagation path before entering the polarization combiner 6.

[0054] In this configuration, a second polarization modulator 4 and a spatial light modulator 5 are provided on the propagation path of the second linearly polarized light 32 before it enters the polarization combiner 6. The second polarization modulator 4 is used to adjust the polarization direction of the second linearly polarized light 32 so that the polarization direction of the second linearly polarized light 32 is the same as that of the first linearly polarized light 31. The spatial light modulator 5 is used to adjust the phase of the edge region of the second linearly polarized light 32 so that the phase of the edge region of the second linearly polarized light 32 differs from the phase of the edge region of the first linearly polarized light 31 by half a cycle.

[0055] Specifically, the second polarization modulator 4 can be a half-wave plate. When the second linearly polarized light 32 is incident on the half-wave plate, the polarization direction of the light will rotate due to the optical path delay effect of the half-wave plate on light with different polarization directions. According to the theory of light polarization, the half-wave plate will rotate the polarization direction of the linearly polarized light passing through it by twice the angle between its fast axis and the polarization direction of the incident light. That is to say, in this embodiment, by adjusting the direction of the fast axis of the half-wave plate, the polarization direction of the second linearly polarized light 32 can be precisely adjusted to be the same as the polarization direction of the first linearly polarized light 31, providing the necessary conditions for the effective merging of the first linearly polarized light 31 and the second linearly polarized light 32 in the polarization combiner 6. The spatial light modulator 5 can be a liquid crystal reflective spatial light modulator 5. The liquid crystal reflective spatial light modulator 5 can be used for laser beams with wavelengths in the range of 400nm to 1100nm, with a liquid crystal pixel pitch of less than 20um, a liquid crystal area size of more than 10mm×10mm, and an adjustable phase range of 0 to 2π. When the second linearly polarized light 32 is incident on the liquid crystal reflective spatial light modulator 5, by applying different voltages to the pixel electrodes of the liquid crystal reflective spatial light modulator 5, the orientation of liquid crystal molecules at each pixel position can be controlled, thereby independently adjusting the phase of the second linearly polarized light 32 passing through that position. For the edge region of the second linearly polarized light 32, a voltage distribution mode can be preset so that the phase of this part of the light differs from the phase of the edge region of the first linearly polarized light 31 by half a cycle. It should be noted that in practical applications, different workpieces 9 and processing techniques have specific requirements for the shape of the laser beam. For example, for some workpieces that require processing of circular holes or circular end grooves, it may be necessary to adjust the laser beam to be circular and have a small spot size; while for some workpieces that require processing of square holes or square end grooves, it may be necessary to adjust the beam to a rectangular shape. In addition, besides controlling the spot shape, the energy distribution of the spot can also be adjusted by adjusting the phase delay of each pixel of the spatial light modulator 5, thereby achieving a higher energy density in the liquid jet 8. In this embodiment, the liquid crystal reflective spatial light modulator 5 has the ability to flexibly adjust the shape of the laser beam. Its principle is based on independent phase modulation of each liquid crystal pixel. Since the pixel pitch is less than 20 μm and the liquid crystal region size is greater than 10 mm × 10 mm, the user can achieve high-density phase modulation within a relatively large area. By applying a voltage distribution pattern to the pixel electrodes that meets the user's requirements, the phase of the second linearly polarized light 32 can be precisely controlled at different positions, thereby changing the wavefront shape of the beam. For example, when the user wants to adjust the laser beam to a circle, a specific phase distribution can be set at the corresponding position of the liquid crystal reflective spatial light modulator 5 according to the geometric characteristics of the circle. For pixels at different radii from the center, the orientation of the liquid crystal molecules is changed by adjusting the voltage, thereby causing different phase delays in the light passing through these positions.This causes the light to form a circular wavefront distribution during propagation, and finally, after passing through the polarization combiner 6 and the coupler 7, the laser beam acting on the workpiece 9 appears circular.

[0056] In the transmission optical path of the second linearly polarized light 32, a polarization beam combiner 6 is provided downstream of the second polarization modulator 4 and the spatial light modulator 5. At the same time, the polarization beam combiner 6 is also in the transmission optical path of the first linearly polarized light 31, so that the polarization beam combiner 6 can receive and combine the first linearly polarized light 31 output by the beam splitter 3 and the second linearly polarized light 32 modulated by the second polarization modulator 4 and the spatial light modulator 5, thereby merging the first linearly polarized light 31 and the second linearly polarized light 32 with the same polarization direction into a single beam in space, realizing the superposition and redistribution of light energy.

[0057] Specifically, the polarization beam combiner 6 can be a beam combiner mirror. See also Figure 4 As shown, when the first linearly polarized light 31 and the second linearly polarized light 32 are incident on the beam combiner, since the polarization directions of the first linearly polarized light 31 and the second linearly polarized light 32 are the same, they will spatially coincide under the action of the beam combiner and propagate in the same direction. Simultaneously, because the phase difference between the edge regions of the first linearly polarized light 31 and the second linearly polarized light 32 is half a period, according to the principle of light interference, the two beams superimpose in the meeting region. At the meeting point of wave crests and troughs, the amplitudes of the light cancel each other out, resulting in a decrease in light intensity; while at the meeting points of wave crests and wave troughs, the light intensity increases. From the distribution of the first linearly polarized light 31 and the second linearly polarized light 32, the energy of the combined laser beam in the edge region decreases due to interference cancellation, which is equivalent to a narrowing of the laser beam width. In the central region, the first linearly polarized light 31 and the second linearly polarized light 32 have no phase difference or the phase difference is not maintained at half a period, resulting in enhanced superposition of light intensity. Here, when the spatial light modulator 5 presets a circular phase distribution mode for the second linearly polarized light 32, see... Figure 3 As shown, the merged laser beam is circular. At this time, within the liquid crystal region of the spatial light modulator 5, based on the circular geometry, different voltages are applied to the pixel electrodes at pixels with different radii from the center, causing the liquid crystal molecules to change orientation, thereby generating different phase delays for the second linearly polarized light 32 passing through these positions. In this way, the wavefront of the second linearly polarized light 32 is adjusted to a circular distribution. After merging with the first linearly polarized light 31, the overall laser beam is circular. This circular beam, guided by the liquid jet 8, acts on the workpiece 9, suitable for processing areas with circular contours such as circular holes and circular grooves. When the liquid crystal reflective spatial light modulator 5 presets a square phase distribution mode for the second linearly polarized light 32, see [reference needed]. Figure 5As shown, the merged laser beam is square. In this case, the spatial light modulator 5 divides the liquid crystal area into different regions for phase modulation according to the positions of the four sides and four corners of the square. For different pixel positions inside and outside the square edge, by precisely applying voltage, the phase of the second linearly polarized light 32 passing through these positions is changed in a specific way, so that after merging with the first linearly polarized light 31, the beam wavefront forms a square distribution, ultimately presenting a square laser beam. The square laser beam can be used to cut square contours of workpieces, process square areas on the surface, etc., and can accurately meet the processing requirements of specific shapes in surface processing and other processing scenarios. It should be noted that... Figure 2 The image shows the energy distribution of the beam spot without phase modulation. In this image, the energy distribution is relatively broad and uniform, with a wide beam width and energy distributed over a large spatial range. No significant changes in energy at the edge regions due to interference are observed. In contrast, Figure 3 This demonstrates the energy distribution of a circular laser beam obtained after phase modulation using this device. Figure 3 It can be clearly observed that the energy in the edge region of the circular beam is significantly reduced due to interference, while the energy originally distributed over a wider area concentrates in the central region, resulting in a noticeably narrower beam width. Compared to Figure 2 , Figure 3 The more compact energy concentration region indicates that a narrower circular laser beam has been successfully achieved through phase modulation, effectively improving energy concentration. This is a significant advantage for scenarios requiring high precision and small spot size processing, enabling more accurate control of the processing area and achieving the processing of even smaller structures. Let's look at... Figure 5 This presents the energy distribution of the square laser beam after phase modulation. Figure 2 compared to, Figure 5 The energy in the edge region of the square beam in the image exhibits a significant cancellation effect due to interference; the energy is no longer as... Figure 3 Instead of being widely distributed, the beam is concentrated within a square outline, significantly narrowing its width in both the horizontal and vertical directions. This narrowed square beam allows for more efficient use of laser energy in applications requiring precise processing of specific shapes, improving processing efficiency while maintaining accuracy. This greatly expands the applicability of laser processing in various shape-related scenarios, demonstrating the significant advantage of this device in controlling the laser beam width based on dual-beam phase adjustment.

[0058] The laser beam, after being combined by the polarization combiner 6, reaches the coupler 7 located on the output optical path of the polarization combiner 6 along the propagation direction. The coupler 7 can couple the laser beam after being combined by the polarization combiner 6 into the liquid jet 8. The characteristics of the liquid jet 8 are used to transmit the laser beam to the workpiece 9, so as to realize the processing of the workpiece 9. The liquid jet 8 plays the role of guiding and transmitting the laser beam, and may also have auxiliary functions such as cooling and chip removal.

[0059] Specifically, the coupler 7 can be a liquid-core fiber coupler 7. The liquid-core fiber coupler 7 contains a liquid channel surrounded by an optical material used to guide the laser beam. The laser beam, after being combined by the polarization combiner 6, is incident on the input end of the liquid-core fiber coupler 7. The liquid-core fiber coupler 7 ensures efficient coupling of the laser beam within the liquid channel, maintaining good transmission characteristics of the laser beam in the liquid environment, reducing energy loss and laser beam divergence, and stably transmitting laser energy to the surface of the workpiece 9.

[0060] In some possible implementations disclosed in this application, see [link to relevant documentation]. Figure 1 As shown, the liquid-guided laser processing device based on dual-beam phase adjustment further includes: a beam pointing adjustment mirror group; the beam pointing adjustment mirror group includes at least a first reflecting mirror 10, a second reflecting mirror 11, a third reflecting mirror 12, and a fourth reflecting mirror 13; the first reflecting mirror 10 and the second reflecting mirror 11 are located between the first polarization modulator 2 and the beam splitter 3; the third reflecting mirror 12 is located on the transmission optical path of the first linearly polarized light 31, and between the beam splitter 3 and the polarization combiner 6; the fourth reflecting mirror 13 is located on the transmission optical path of the second linearly polarized light 32, and between the spatial light modulator 5 and the polarization combiner 6.

[0061] In this embodiment, by setting a beam pointing adjustment mirror group, the transmission direction of the laser beam can be flexibly changed, so that the laser beam is transmitted along a predetermined route, ensuring the compactness and rationality of the entire processing device.

[0062] The first reflecting mirror 10 and the second reflecting mirror 11 are used to adjust the propagation direction of the circularly polarized light to be perpendicular to the incident surface of the beam splitter 3.

[0063] Specifically, the first reflector 10 and the second reflector 11 are arranged parallel to each other, and both are parallel to the reflecting surface of the beam splitter 3.

[0064] The third mirror 12 is used to reflect the first linearly polarized light 31 to the polarization combiner 6.

[0065] Specifically, the third mirror 12 is also parallel to the reflecting surface of the beam splitter 3, and the third mirror 12 is also parallel to the reflecting surface of the polarization combiner 6.

[0066] The fourth reflector 13 is used to reflect the second linearly polarized light 32, which has been modulated by the second polarization modulator 4 and the spatial light modulator 5, to the polarization combiner 6.

[0067] Specifically, the fourth reflector 13 is located above the polarization combiner 6, and the propagation directions of the first linearly polarized light 31 and the second linearly polarized light 32 are perpendicular to each other before entering the polarization combiner 6.

[0068] In some possible implementations disclosed in this application, see [link to relevant documentation]. Figure 1 As shown, the liquid-guided laser processing device based on dual-beam phase adjustment further includes: a condenser lens group; the condenser lens group includes at least a first condenser lens 14; the first condenser lens 14 is located between the polarization combiner 6 and the coupler 7.

[0069] In this embodiment, by setting the first condenser lens 14, the laser beam combined by the polarization combiner 6 can be focused, thereby increasing the energy density of the laser beam.

[0070] The first condenser lens 14 can be a spherical or aspherical lens made of transparent materials such as optical glass. It can use the principle of light refraction to converge the laser beam after it has been combined by the polarization combiner 6, thereby increasing the energy density of the laser beam.

[0071] Specifically, the laser beam emitted from the polarization combiner 6 will be incident on the first condenser 14. After being refracted by the first condenser 14, the laser beam will converge towards the central axis and then be transmitted to the coupler 7.

[0072] In some possible implementations disclosed in this application, see [link to relevant documentation]. Figure 1 As shown, the liquid-guided laser processing device based on dual-beam phase adjustment also includes: a liquid supply system 15; a jet hole is opened at the bottom of the coupler 7, and a coupling cavity is provided inside the coupler 7. The coupling cavity is connected to the jet hole and the liquid supply system 15 respectively. The liquid supply system 15 is used to transport high-pressure liquid medium to the coupling cavity. The high-pressure liquid medium is configured to be ejected through the jet hole to form a liquid jet 8.

[0073] In this embodiment, by setting up a liquid supply system 15, a high-pressure liquid medium can be stably delivered to the coupling cavity, and then ejected through the jet hole to form a liquid jet 8, ensuring the stability and accuracy of the processing.

[0074] The coupling cavity is used to contain the high-pressure liquid medium from the liquid supply system 15, providing a stable environment for the coupling of the laser beam and the high-pressure liquid medium.

[0075] The high-pressure liquid medium supplied by the liquid supply system 15 to the coupling cavity can be one or a mixture of pure water, inorganic salt solution, mineral oil, kerosene, glycerin, propylene glycol, and polyvinyl alcohol. The flow rate of the high-pressure liquid medium can be 0.05 L / H to 50 L / H, and the pressure of the high-pressure liquid medium can be 2 MPa to 100 MPa.

[0076] Specifically, in this embodiment, the high-pressure liquid medium supplied by the liquid supply system 15 to the coupling cavity is mineral oil. The interface between the liquid jet 8 formed by the mineral oil and the space can totally reflect the laser beam, thereby forming an extremely high instantaneous laser power density, and effectively removing the material from the workpiece 9.

[0077] The jet orifice, which connects to the bottom of the coupling cavity, serves as the channel for the high-pressure liquid medium to flow out of the coupler 7, allowing the high-pressure liquid medium to be ejected through the jet orifice. The jet orifice can be circular, rectangular, or rounded rectangular, etc. When the jet orifice is circular, its diameter is 5μm to 150μm; when the jet orifice is rectangular or rounded rectangular, its width is 5μm to 150μm, and its aspect ratio is 1 to 50.

[0078] Specifically, in this embodiment, the jet hole is circular with a diameter of 15 μm. The material at the jet hole at the bottom of the coupling cavity is stainless steel, copper, diamond, sapphire, ruby, or a non-metallic material, which is used to ensure the stability and uniformity of the liquid jet 8, maintain the consistency of the coupling between the laser beam and the liquid jet 8, thereby ensuring the stability of the processing process and the reliability of the processing quality.

[0079] In some possible implementations disclosed in this application, see [link to relevant documentation]. Figure 1 As shown, the liquid-guided laser processing device based on dual-beam phase adjustment also includes: a heat sink block 16; a polarization beam combiner 6 having a main emission surface and a side emission surface, the main emission surface being arranged toward the coupler 7 and the side emission surface being arranged toward the heat sink block 16.

[0080] In this embodiment, the heat sink block 16 can absorb the heat emitted from the side exit surface of the polarization combiner 6, thereby playing a heat dissipation role, protecting the polarization combiner 6 and other surrounding optical components, enabling them to work in a stable temperature environment, and ensuring the optical performance of the entire device.

[0081] In practical applications, after the first linearly polarized light 31 enters the polarization combiner 6, a portion of the first linearly polarized light 31 merges with the second linearly polarized light 32 under the action of the polarization combiner 6, while the other portion of the first linearly polarized light 31 enters the heat sink block 16 under the action of the polarization combiner 6. Similarly, after the second linearly polarized light 32 enters the polarization combiner 6, a portion of the second linearly polarized light 32 merges with the first linearly polarized light 31 under the action of the polarization combiner 6, while the other portion of the second linearly polarized light 32 enters the heat sink block 16 under the action of the polarization combiner 6.

[0082] Specifically, in this embodiment, after the first linearly polarized light 31 and the second linearly polarized light 32 are incident on the polarization combiner 6, 50% of the first linearly polarized light 31 and 50% of the second linearly polarized light 32 enter the heat sink block 16 under the action of the polarization combiner 6.

[0083] In some possible implementations disclosed in this application, see [link to relevant documentation]. Figure 1 As shown, the liquid-guided laser processing device based on dual-beam phase adjustment also includes: an image acquisition device 17; the image acquisition device 17 is located on the side of the coupler 7 away from the workpiece 9 to be processed, and the detection end of the image acquisition module is set towards the coupler 7.

[0084] In this embodiment, by setting up the image acquisition device 17, the position information of the spot formed by the laser beam at the bottom of the coupler 7 and the position information of the jet hole at the bottom of the coupler 7 can be detected. This helps to determine whether the laser beam accurately enters the liquid jet 8 area, and provides guidance for the user to adjust the transmission optical path of the laser beam or the position of the coupler 7, ensuring that the laser beam is accurately coupled with the jet nozzle.

[0085] Among them, the image acquisition device 17 can be a surveillance camera (CCD), etc.

[0086] Specifically, when there is a deviation between the laser beam spot formed by the laser beam at the bottom of the coupler 7 and the jet hole at the bottom of the coupler 7 (not overlapping or not completely overlapping), the user can make fine adjustments to the transmission optical path of the laser beam or the position of the coupler 7 based on the image fed back by the image acquisition device 17, so that the laser beam can be coupled into the liquid jet 8 at the best angle and position, minimizing the energy loss of the laser beam during the coupling process and ensuring that the laser energy is efficiently transmitted to the workpiece 9 to be processed.

[0087] In some possible embodiments disclosed in this application, the liquid-guided laser processing device based on dual-beam phase adjustment further includes: a coupling adjustment mechanism (not shown in the figure); the coupling adjustment mechanism includes at least a first motion component, a second motion component and a third motion component; the first motion component is connected to the spatial light modulator 5; the second motion component is connected to the fourth reflector 13; and the third motion component is connected to the coupler 7.

[0088] In this embodiment, by setting a coupling adjustment mechanism, the transmission optical path of the laser beam and the position of the coupler 7 can be adjusted so that the laser beam can be coupled into the liquid jet 8 at the optimal angle and position, minimizing the energy loss of the laser beam during the coupling process and ensuring that the laser energy is efficiently transmitted to the workpiece 9 to be processed.

[0089] The first motion component, the second motion component, and the third motion component each have at least two degrees of freedom, including translational and rotational degrees of freedom. The translational degree of freedom enables the motion component to make linear displacement in a plane or space direction, changing the position of the connected parts. The rotational degree of freedom allows the motion component to rotate around a specific axis, thereby adjusting the angle and attitude of the connected parts.

[0090] Specifically, the first motion component is connected to the spatial light modulator 5. Its translational degree of freedom allows the spatial light modulator 5 to move horizontally or vertically, precisely calibrating the incident position of the laser beam. Its rotational degree of freedom allows the spatial light modulator 5 to rotate around an axis, flexibly changing the modulation angle of the laser beam to meet different processing requirements. Similarly, the second motion component is connected to the fourth reflector 13. Relying on translational and rotational degrees of freedom, the position and angle of the fourth reflector 13 can be precisely controlled to ensure that the laser beam propagates along a predetermined path. The third motion component is connected to the coupler 7. Through translational and rotational operations, the spatial position and attitude of the coupler 7 can be adjusted in all directions to achieve the optimal coupling effect between the laser beam and the liquid jet 8.

[0091] Furthermore, to fully illustrate the specific implementation process of this embodiment, a liquid-guided laser processing method based on dual-beam phase adjustment is provided, see [link to relevant documentation]. Figure 6 As shown, the method includes:

[0092] Step S101: Detect the center position of the first linearly polarized light spot 31 at the bottom of the coupler 7.

[0093] Here, determining the center position of the spot formed by the first linearly polarized light 31 at the bottom of the coupler 7 provides a basis for subsequently adjusting the propagation path of the second linearly polarized light 32. Specifically, an image acquisition device 17 (such as a CCD monitor camera) can be used to detect the center position of the spot of the first linearly polarized light 31 at the bottom of the coupler 7. The image acquisition device 17 is located on the side of the coupler 7 away from the workpiece 9, with its detection end facing the coupler 7. It can capture an image of the bottom of the coupler 7 and identify the center position of the spot of the first linearly polarized light 31 from the image using image processing technology.

[0094] Step S201: Detect the center position of the second linearly polarized light spot 32 at the bottom of the coupler 7.

[0095] Here, the center position of the spot formed by the second linearly polarized light 32 at the bottom of the coupler 7 is determined so that it can be aligned with the center of the spot of the first linearly polarized light 31 in subsequent adjustments. Specifically, the center position of the spot of the second linearly polarized light 32 at the bottom of the coupler 7 can also be detected using the image acquisition device 17. By capturing an image of the bottom of the coupler 7, the center position information of the spot of the second linearly polarized light 32 is extracted from the image using an image processing algorithm.

[0096] Step S301: Adjust the optical path so that the center of the spot of the first linearly polarized light 31 at the bottom of the coupler 7 coincides with the center of the spot of the second linearly polarized light 32.

[0097] Here, the centers of the first linearly polarized light 31 and the second linearly polarized light 32 are ensured to coincide at the bottom of the coupler 7, enabling accurate spatial superposition of the two beams. This lays the foundation for effective merging of the first and second linearly polarized lights 31 and 32 in the polarization combiner 6, as well as for achieving laser beam width control and interference effects. Specifically, the propagation path of the first linearly polarized light 31 can be kept unchanged, and the propagation path of the second linearly polarized light 32 can be adjusted using only the first and second motion components in the coupling adjustment mechanism. The first motion component is connected to the spatial light modulator 5. Its translational degree of freedom allows the spatial light modulator 5 to move horizontally or vertically, thereby precisely calibrating the incident position of the second linearly polarized light 32. Its rotational degree of freedom allows the spatial light modulator 5 to rotate around its axis, flexibly changing the modulation angle of the second linearly polarized light 32. The second motion component is connected to the fourth reflector 13. Relying on translation and rotation degrees of freedom, it can precisely control the position and angle of the fourth reflector 13 to ensure that the second linearly polarized light 32 propagates along a predetermined path, and finally achieve the overlap of the center of the light spot at the bottom of the coupler 7 with the first linearly polarized light 31 and the second linearly polarized light 32.

[0098] Step S401: Adjust the position of the coupler 7 so that the center of the jet hole at the bottom of the coupler 7, the center of the spot of the first linearly polarized light 31, and the center of the spot of the second linearly polarized light 32 coincide.

[0099] Here, the alignment of the center of the jet hole at the bottom of the coupler 7, the center of the spot of the first linearly polarized light 31, and the center of the spot of the second linearly polarized light 32 ensures that the laser beam is accurately coupled into the liquid jet 8, minimizing energy loss during coupling and ensuring efficient transmission of laser energy to the workpiece 9. Specifically, the position of the coupler 7 can be adjusted using the third motion component connected to the coupler 7 in the coupling adjustment mechanism, thereby adjusting the position of the jet hole. This third motion component has translational and rotational degrees of freedom. Translation allows the coupler 7 to move linearly in a plane or space, changing its position; rotation allows the coupler 7 to rotate around a specific axis, adjusting its angle and orientation. These operations comprehensively adjust the spatial position and orientation of the coupler 7, ensuring that the center of the jet hole at the bottom of the coupler 7, the center of the spot of the first linearly polarized light 31, and the center of the spot of the second linearly polarized light 32 coincide, achieving optimal coupling between the laser beam and the liquid jet 8.

[0100] Furthermore, prior to step S101, the liquid-guided laser processing method based on dual-beam phase adjustment includes:

[0101] Step S100: Replace the first polarization modulator 2 with the third polarization modulator; adjust the third polarization modulator so that it can convert the linearly polarized light emitted by the laser source 1 into the first linearly polarized light 31, which is suitable for total reflection by the beam splitter 3.

[0102] It should be noted that in the normal processing flow, the function of the first polarization modulator 2 (such as a quarter-wave plate) is to convert the linearly polarized light emitted from the laser source 1 into circularly polarized light, so as to achieve subsequent separation and modulation of the two beams. However, when detecting the center position of the spot of the first linearly polarized light 31 at the bottom of the coupler 7, it is necessary to directly generate the first linearly polarized light 31 in order to avoid interference from the second linearly polarized light 32. Therefore, the first polarization modulator 2 is replaced with a third polarization modulator to directly obtain the required first linearly polarized light 31, simplifying the detection process and improving the accuracy of detection.

[0103] Here, the third polarization modulator can be a half-wave plate. The half-wave plate rotates the polarization direction of the linearly polarized light passing through it by twice the angle between its fast axis and the polarization direction of the incident light by adjusting the direction of the fast axis of the half-wave plate. That is, by adjusting the direction of the fast axis of the half-wave plate, precise control of the polarization direction of the linearly polarized light emitted by the laser source 1 can be achieved. The beam splitter 3 (such as a polarizing beam splitter) has a selective effect on light with different polarization directions; only light with a specific polarization direction can be totally reflected by it. Therefore, in step S100, the half-wave plate is adjusted so that the polarization direction of the linearly polarized light emitted by the laser source 1, after passing through the half-wave plate, exactly meets the condition that it can be totally reflected by the beam splitter 3, thus obtaining the desired first linearly polarized light 31.

[0104] Furthermore, prior to step S201, the liquid-guided laser processing method based on dual-beam phase adjustment includes:

[0105] Step S200: Adjust the third polarization modulator so that it can convert the linearly polarized light emitted by the laser source 1 into second linearly polarized light 32, which is suitable for complete transmission through the beam splitter 3.

[0106] Here, the purpose of step S200 is to directly generate the required second linearly polarized light 32 when detecting the center position of the second linearly polarized light 32 at the bottom of the coupler 7, avoiding interference caused by complex operations such as dual-beam separation in the normal processing flow, thereby simplifying the detection process and improving the accuracy of detection. Specifically, after step S101 is completed, the fast axis direction of the third polarization modulator (such as a half-wave plate) can be adjusted again to convert the linearly polarized light emitted by the laser source 1 into second linearly polarized light 32 that can completely pass through the beam splitter 3 (such as a polarizing beam splitter), providing an accurate and pure detection object for the subsequent step S201 (detecting the center position of the second linearly polarized light 32 at the bottom of the coupler 7), ensuring the smooth progress of the spot center position detection link in the entire liquid-guided laser processing method.

[0107] It will be readily understood by those skilled in the art that the aforementioned advantageous methods can be freely combined and superimposed without conflict.

[0108] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application. The above are merely preferred embodiments of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this application, and these improvements and modifications should also be considered within the protection scope of this application.

Claims

1. A liquid-guided laser processing device based on dual-beam phase adjustment, characterized in that, include: Laser source (1), first polarization modulator (2), beam splitter (3), second polarization modulator (4), spatial light modulator (5), polarization beam combiner (6) and coupler (7); The first polarization modulator (2) is located on the output optical path of the laser source (1) and is used to convert the linearly polarized light emitted by the laser source (1) into circularly polarized light. The beam splitter (3) is disposed downstream of the first polarization modulator (2) along the propagation direction of the circularly polarized light and is used to separate the circularly polarized light into a first linearly polarized light (31) and a second linearly polarized light (32). The second polarization modulator (4) and the spatial light modulator (5) are located on the transmission optical path of the second linearly polarized light (32) and between the beam splitter (3) and the polarization combiner (6). The second polarization modulator (4) is used to adjust the polarization direction of the second linearly polarized light (32) to be similar to that of the first linearly polarized light. The polarization directions of (31) are the same. The spatial light modulator (5) is used to adjust the phase of the edge region of the second linearly polarized light (32) to be half a cycle different from the phase of the edge region of the first linearly polarized light (31). The polarization beam combiner (6) is used to receive and combine the first linearly polarized light (31) output by the beam splitter (3) and the second linearly polarized light (32) modulated by the second polarization modulator (4) and the spatial light modulator (5). The coupler (7) is located on the output light path of the polarization beam combiner (6). The coupler (7) is used to couple the laser beam after being combined by the polarization beam combiner (6) into the liquid jet (8). The liquid jet (8) acts on the workpiece (9).

2. The liquid-guided laser processing device based on dual-beam phase adjustment according to claim 1, characterized in that, Also includes: Beam pointing adjustment lens group; The beam pointing adjustment mirror group includes at least a first reflector (10), a second reflector (11), a third reflector (12), and a fourth reflector (13); The first reflector (10) and the second reflector (11) are located between the first polarization modulator (2) and the beam splitter (3); The third reflector (12) is located on the transmission optical path of the first linearly polarized light (31) and between the beam splitter (3) and the polarization combiner (6); The fourth reflector (13) is located on the transmission optical path of the second linearly polarized light (32) and between the spatial light modulator (5) and the polarization combiner (6).

3. The liquid-guided laser processing device based on dual-beam phase adjustment according to claim 1, characterized in that, Also includes: Condenser lens assembly; The condenser lens group includes at least a first condenser lens (14); The first condenser (14) is located between the polarization combiner (6) and the coupler (7).

4. The liquid-guided laser processing apparatus based on dual-beam phase adjustment according to claim 1, characterized in that, Also includes: Liquid supply system (15); The coupler (7) has a jet hole at its bottom and a coupling cavity inside the coupler (7). The coupling cavity is connected to the jet hole and the liquid supply system (15) respectively. The liquid supply system (15) is used to deliver a high-pressure liquid medium to the coupling cavity. The high-pressure liquid medium is configured to be ejected through the jet hole to form the liquid jet (8).

5. The liquid-guided laser processing apparatus based on dual-beam phase adjustment according to claim 1, characterized in that, Also includes: Heat sink block (16); The polarization combiner (6) has a main exit surface and a side exit surface, the main exit surface being disposed toward the coupler (7) and the side exit surface being disposed toward the heat sink block (16).

6. The liquid-guided laser processing apparatus based on dual-beam phase adjustment according to claim 1, characterized in that, Also includes: Image acquisition device (17); The image acquisition device (17) is located on the side of the coupler (7) away from the workpiece (9), and the detection end of the image acquisition module is set towards the coupler (7).

7. The liquid-guided laser processing apparatus based on dual-beam phase adjustment according to claim 2, characterized in that, Also includes: Coupling adjustment mechanism; The coupling adjustment mechanism includes at least a first motion component, a second motion component, and a third motion component; The first motion component is connected to the spatial light modulator (5); the second motion component is connected to the fourth reflector (13); and the third motion component is connected to the coupler (7).

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