Dynamic beam shaping module and laser powder bed fusion shaping light path system

Abstract

The invention relates to a dynamic beam shaping module and a laser powder bed melting shaping light path system, and belongs to the technical field of laser additive manufacturing. A dynamic beam shaping module comprises a diffractive optical element, the diffractive optical element comprises a light-transmitting substrate, and the surface of the light-transmitting substrate is provided with at least two independent diffractive functional areas which are not overlapped and are used for shaping laser beams with a first shape and a first energy distribution characteristic into laser beams with different shapes and / or different energy distribution characteristics; the light path adjusting mechanism is used for adjusting the different independent diffraction functional areas to be sequentially aligned with the laser beams in the first shape and the first energy distribution characteristic; and the beam expander is used for dynamically adjusting the laser beam entering the surface of the diffractive optical element. The defect that a traditional static diffractive optical element needs to be replaced by printing interruption is overcome, the stability of optical path structure switching is remarkably improved, and mechanical displacement errors caused by element switching are eliminated.

Description

Technical Field

[0001] This invention relates to the field of laser additive manufacturing technology, and in particular to a dynamic beam shaping module and a laser powder bed melting and shaping optical path system. Background Technology

[0002] Existing laser powder bed melting equipment mostly uses Gaussian laser beams. Due to the energy distribution characteristics of "high at the center and low at the edges," it is prone to causing large and unstable thermal gradients in the molten pool, leading to metallurgical defects such as cracks, pores, and spatter erosion, as well as the formation of high-temperature, weak, large-angle grain boundary structures, severely restricting the forming quality and material properties. Although the defects of Gaussian beams can be compensated by adjusting process parameters such as laser power, scanning speed, powder layer thickness, and scanning strategy, the inherent physical limitations of Gaussian beams restrict the optimization window, often resulting in a trade-off between efficiency and quality. Laser beam shaping technology, by converting Gaussian beams into novel spot shapes such as flat-top, annular, or Bezier beams, reconstructs the laser energy distribution pattern and precisely adjusts the temperature distribution and flow characteristics of the molten pool to obtain a relatively stable molten pool with a smaller temperature gradient. This helps suppress spatter and porosity defects and improves the uniformity of microstructure. This technology breaks through the physical bottleneck of traditional process parameter adjustment, significantly expanding the power-speed synergistic optimization space while improving printing quality, and providing new degrees of freedom for multi-dimensional processing strategy design. It has become a key technological breakthrough driving the development of laser additive manufacturing towards high precision and high performance.

[0003] Based on the principle of beam transformation, beam shaping technology is mainly divided into refractive and diffractive laser shaping systems. Refractive laser shaping elements (such as lens arrays and prism arrays) reorganize the spatial energy of the input laser through the principle of geometrical optics refraction. Diffractive laser shaping elements (such as diffractive optical elements, diffractive microlens arrays, and liquid crystal spatial light modulators) are based on wave optics, using micro / nano structures to modulate the phase and amplitude of the laser wavefront, achieving spatial shaping of the laser beam through diffraction transmission and interference superposition at different positions. While liquid crystal spatial modulators can dynamically adjust the spatial phase, intensity, and polarization state of the beam, they are expensive and have low optical threshold power. Refractive laser shaping elements and traditional single-function diffractive optical elements (DOEs) can only achieve static beam shaping. Although these technologies can improve energy distribution, beam mode switching requires replacing physical components that require manual switching during interrupted printing, making it difficult to meet the rapid prototyping requirements of laser powder bed fusion additive manufacturing. Summary of the Invention

[0004] Therefore, it is necessary to provide a dynamic beam shaping module and a laser powder bed melting shaping optical path system to address the problem that static shaping of traditional diffractive optical elements requires interruption of printing for manual replacement and recalibration.

[0005] The first aspect of this application discloses a dynamic beam shaping module, which includes:

[0006] A diffractive optical element, comprising a light-transmitting substrate, the surface of which has at least two independent diffraction functional regions that do not overlap, each independent diffraction functional region having a different micro / nano relief structure, the micro / nano relief structure being used to adjust the wavefront phase and amplitude of a laser beam to reconstruct the spatial energy distribution characteristics of the laser beam, the different independent diffraction functional regions being used to shape a laser beam of a first shape and a first energy distribution characteristic into a laser beam of a different shape and / or a different energy distribution characteristic;

[0007] An optical path adjustment mechanism is provided to adjust the different independent diffraction functional regions to sequentially align with a laser beam that has a first shape and a first energy distribution characteristic.

[0008] A beam expander is used to dynamically adjust the incident diameter and divergence angle of a laser beam incident on the surface of the diffractive optical element.

[0009] In one embodiment, the etching depth of the micro / nano relief structure is designed based on a reverse iterative algorithm, which is solved according to the phase and amplitude distribution of the input beam and the target output beam; the first shape of the input beam includes a circle, rectangle, square, ellipse and straight line, the first energy distribution characteristics of the input beam include Gaussian beam, uniform beam and dot ring beam, and the type of the target output beam includes Gaussian beam, uniform beam, vortex beam, Bessel beam, ring beam and dot ring beam.

[0010] In one embodiment, all of the independent diffraction functional regions include a first diffraction functional region that shapes a circular Gaussian spot into a circular uniform spot, a second diffraction functional region that shapes a circular Gaussian spot into a square uniform spot, and a third diffraction functional region that shapes a circular Gaussian spot into a ring-shaped spot.

[0011] In one embodiment, all of the independent diffraction functional regions include a first diffraction functional region that shapes a rectangular uniform light spot into an elliptical uniform light spot, and a second diffraction functional region that shapes a rectangular uniform light spot into a square Gaussian light spot.

[0012] In one embodiment, all of the independent diffraction functional regions include a first diffraction functional region for shaping a circular Gaussian spot into a circular Bessel spot, a second diffraction functional region for shaping a circular Gaussian spot into a square Bessel spot, a third diffraction functional region for shaping a circular Gaussian spot into an elliptical uniform spot, and a fourth diffraction functional region for shaping a circular Gaussian spot into an annular spot.

[0013] In one embodiment, all of the independent diffraction functional regions include a first diffraction functional region that shapes a circular uniform light spot into a circular Gaussian light spot, a second diffraction functional region that shapes a circular uniform light spot into a square uniform light spot, and a third diffraction functional region that shapes a circular uniform light spot into a ring light spot.

[0014] In one embodiment, all of the independent diffraction functional regions include a first diffraction functional region for shaping a circular Gaussian spot into a circular Bessel spot, a second diffraction functional region for shaping a circular Gaussian spot into a square Bessel spot, a third diffraction functional region for shaping a circular Gaussian spot into an elliptical uniform spot, and a fourth diffraction functional region for shaping a circular Gaussian spot into an annular spot.

[0015] In one embodiment, all of the independent diffraction functional regions include a first diffraction functional region that shapes a circular uniform light spot into a circular Gaussian light spot, a second diffraction functional region that shapes a circular uniform light spot into a square uniform light spot, and a third diffraction functional region that shapes a circular uniform light spot into a square uniform light spot.

[0016] In one embodiment, the connection between the diffractive optical element and the optical path adjustment mechanism is either an integral package or a separate package.

[0017] In one embodiment, the diffractive optical element uses a circular substrate, a rectangular substrate, or a hollow annular substrate.

[0018] In one embodiment, the electric component is an electric rotation component or an electric displacement component.

[0019] In one embodiment, the connection between the diffractive optical element and the optical path adjustment mechanism is an integral package. The diffractive optical element adopts a circular substrate, and a bearing through hole is opened in the center of the diffractive optical element. The electric component is an electric rotating component, which includes a transmission worm, a transmission worm wheel, a transmission pin, and a first bearing. The transmission worm is connected to the stepper motor and the transmission worm wheel respectively. The transmission worm wheel has a threaded through hole and a threaded retaining ring adapted to the through hole. The surface of the transmission worm wheel is machined with first grooves arranged at equal angular intervals. The sensor is a rotation angle infrared sensor. The sensor detects the angle of the transmission worm wheel through the first groove. The transmission pin is connected to the diffractive optical element and the transmission worm wheel respectively. The first bearing is installed in the bearing through hole, and the first bearing cooperates with the transmission worm wheel through the bearing through hole to form a rotating pair.

[0020] In one embodiment, the connection between the diffractive optical element and the optical path adjustment mechanism is an integral package. The diffractive optical element adopts a rectangular substrate, and the electric component is an electric displacement component. The electric displacement component includes a diffractive optical element fixing platform, a transmission rack, and a transmission gear. The diffractive optical element is disposed on the diffractive optical element fixing platform, and the diffractive optical element fixing platform is disposed on one side of the transmission rack. The side of the transmission rack away from the diffractive optical element fixing platform is connected to the transmission gear. The transmission rack and the transmission gear cooperate to form a kinematic pair. The surface of the transmission rack is machined with second grooves arranged at equal intervals. The sensor is a position sensor, and the sensor detects the position of the transmission rack through the second grooves.

[0021] In one embodiment, the connection between the diffractive optical element and the optical path adjustment mechanism is a separate package. The diffractive optical element uses a hollow annular substrate, and the electric component is an electric rotating component. The electric rotating component includes a diffractive optical element fixing component and a rotating shaft. The diffractive optical element is disposed on the diffractive optical element fixing component, and the rotating shaft passes through the diffractive optical element. The optical path adjustment mechanism further includes a mirror assembly. The mirror assembly includes a first mirror group, a first mirror group mounting component, a second mirror group, a second mirror group mounting component, a first mirror, and a second mirror. The first mirror group is disposed on the first mirror group mounting component. The first mirror group includes a third mirror, a fourth mirror, and a fifth mirror arranged at equal intervals. Two reflector groups are mounted on the second reflector group mounting component. The second reflector group includes a sixth, seventh, and eighth reflector arranged at equal intervals. The surfaces of both the first and second reflector group mounting components are machined with third grooves arranged at equal angular intervals. The sensor is a rotation angle infrared sensor. The sensor detects the angle of the first and second reflector group mounting components through the third grooves. The first and second reflectors are respectively located at both ends of the rotating shaft. The first and second reflectors are mirror-symmetrically arranged with respect to the diffractive optical element. The first reflector is at least partially opposite to the first reflector group, and the second reflector is at least partially opposite to the second reflector group.

[0022] The second aspect of this application discloses a laser powder bed melting and shaping optical path system, which includes the aforementioned dynamic beam shaping module, a laser, a scanning galvanometer, a field mirror, and a powder bed forming cavity. The laser is used to emit a collimated beam to the dynamic beam shaping module. The field mirror is connected to the scanning galvanometer via a junction ring. The powder bed forming cavity and the light outlet of the field mirror are arranged opposite each other. The beam emitted by the laser passes sequentially through the beam expander, the diffractive optical element, and the scanning galvanometer, and is finally focused by the field mirror onto the surface of the forming cylinder inside the powder bed forming cavity, thereby completing the layer-by-layer melting and shaping of metal powder according to the quality control system.

[0023] The beneficial effects of the dynamic beam shaping module and laser powder bed melting shaping optical path system provided by this invention are as follows: the diffractive optical element has multiple independent diffraction functional regions. By adjusting the movement of the diffractive optical element through the optical path adjustment mechanism, combined with the dynamic adjustment of the incident laser beam parameters by the beam expander, dynamic real-time switching of different beam energy distributions and spot types can be achieved. Compared with manually or electrically switching multiple single-function diffractive optical elements, this not only enhances the stability and accuracy of the optical path structure switching process and eliminates the mechanical displacement error introduced by the switching of diffractive optical elements, but also simplifies the optical path. The structure makes the entire optical path system more compact; and the response time is as low as tens of milliseconds, effectively overcoming the inefficiency of traditional methods that require interrupting printing, manually switching components, and recalibrating. Compared with laser direct shaping or spatial light modulators and other beam dynamic shaping solutions, the multifunctional diffractive optical element provided by this invention, with at least two independent diffraction functional regions on its surface having different micro-nano relief structures, can meet diverse beam shaping needs. Its simple combination with the optical path adjustment mechanism makes it easier to achieve low-cost, high-damage-threshold dynamic beam shaping, which is more advantageous in laser powder bed melting applications. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a laser powder bed melting and shaping optical path system;

[0025] Figure 2 A schematic diagram showing the specific structural division of the diffractive optical element and the preset laser beam incident position switching motion trajectory;

[0026] Figure 3 A first schematic diagram of an integrated package for diffractive optical elements and optical path adjustment mechanisms;

[0027] Figure 4 A second schematic diagram showing an integrated package of diffractive optical elements and optical path adjustment mechanisms;

[0028] Figure 5 A schematic diagram of a separate package for diffractive optical elements and optical path adjustment mechanisms;

[0029] Figure 6 This is a schematic diagram of the installation of the laser powder bed melting and shaping optical path system.

[0030] The correspondence between the reference numerals and the component names is as follows:

[0031] 100 Dynamic beam shaping module, 1 diffractive optical element, 11 Transparent substrate, 101 Independent diffraction functional area, 1011 First diffraction functional area, 1012 Second diffraction functional area, 1013 Third diffraction functional area, 1014 Fourth diffraction functional area, 102 Bearing through hole, 2 Optical path adjustment mechanism, 21 Stepper motor, 22 Sensor, 23 Electric rotating assembly, 231 Transmission worm gear, 232 Transmission worm wheel, 233 Transmission pin, 234 First bearing, 235 Diffractive optical element fixing component, 236 Rotating shaft, 2 4. Electric displacement assembly; 241. Diffractive optical element fixing platform; 242. Transmission rack; 243. Transmission gear; 25. Reflector assembly; 251. First reflector group; 2511. Third reflector; 2512. Fourth reflector; 2513. Fifth reflector; 252. First reflector group mounting piece; 253. Second reflector group; 2531. Sixth reflector; 2532. Seventh reflector; 2533. Eighth reflector; 254. Second reflector group mounting piece; 255. First reflector; 256. Second reflector; 3. Beam expander;

[0032] 200 laser;

[0033] 300 scanning galvanometer;

[0034] 400 shots;

[0035] 500 coupling;

[0036] 600 powder bed forming cavity;

[0037] 700 Mounting assembly, 71 Galvanometer mounting adapter, 72 Protective mirror mounting adapter, 73 First protective mirror;

[0038] 800 Motion device, 81 Lifting device, 82 Carrying platform, 83 Second protective mirror. Detailed Implementation

[0039] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0040] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0041] The following description, with reference to the accompanying drawings, describes some embodiments of the dynamic beam shaping module and laser powder bed melting shaping optical path system of the present invention.

[0042] Example 1

[0043] like Figure 1 and Figure 2 As shown, this embodiment discloses a dynamic beam shaping module, including a diffractive optical element 1, an optical path adjustment mechanism 2, and a beam expander 3. The diffractive optical element 1 includes a light-transmitting substrate 11, the surface of which has at least two independent diffractive functional regions 101 that do not overlap. Different independent diffractive functional regions 101 are provided with different micro-nano relief structures. The micro-nano relief structures are used to adjust the wavefront phase and amplitude of the laser beam to reconstruct the spatial energy distribution characteristics of the laser beam. Different independent diffractive functional regions 101 are used to shape the laser beam with a first shape and a first energy distribution characteristic into a laser beam with a different shape and / or a different energy distribution characteristic. The optical path adjustment mechanism 2 adjusts the different independent diffractive functional regions 101 to align sequentially with the laser beam with the first shape and the first energy distribution characteristic. The beam expander 3 is used to dynamically adjust the incident diameter and divergence angle of the laser beam incident on the surface of the diffractive optical element 1.

[0044] Compared to manually or electrically switching multiple single-function diffractive optical elements 1, the diffractive optical element 1 has multiple independent diffraction functional regions 101. The movement of the diffractive optical element 1 is adjusted by the optical path adjustment mechanism 2, and combined with the dynamic adjustment of the incident laser beam parameters by the beam expander 3, dynamic real-time switching of different beam energy distributions and spot types can be achieved. This not only enhances the stability and accuracy of the optical path switching process and eliminates mechanical displacement errors introduced by the switching of the diffractive optical element 1, but also simplifies the optical path structure, making the entire optical path system more compact. Furthermore, the response time is as low as tens of milliseconds, effectively overcoming the inefficiency of traditional methods that require interrupting printing, manually switching elements, and recalibrating. Compared to direct laser shaping or spatial light modulators and other dynamic beam shaping schemes, the multifunctional diffractive optical element 1 used in this application, with at least two independent diffraction functional regions 101 having different micro / nano relief structures on its surface, can meet diverse beam shaping needs. Its simple combination with the optical path adjustment mechanism 2 makes it easier to achieve low-cost, high-damage-threshold dynamic beam shaping, giving it a greater advantage in laser powder bed melting applications.

[0045] In addition to the features of the above embodiments, this embodiment further specifies that: the number of independent diffraction functional regions 101 is determined by the types of beam modes required by the optical path system, and includes at least two independent diffraction functional regions 101 with independent shaping effects. Clearly defining the number of independent diffraction functional regions 101 as determined by the types of beam modes required by the optical path system ensures that the number of functional regions matches the actual shaping requirements, avoiding insufficient functional regions that cannot meet multi-mode shaping needs, or excessive functional regions that cause structural redundancy; simultaneously, specifying at least two functional regions with independent shaping effects provides the necessary conditions for the dynamic beam shaping module to switch between at least two different beam shapes and / or energy distributions, ensuring the module's dynamic shaping capability and laying a quantitative foundation for adapting to different optical path application scenarios.

[0046] In addition to the features of the above embodiments, this embodiment further specifies that: the independent diffraction functional regions 101 can independently generate specific diffraction patterns and energy distribution states without interfering with or affecting each other. This ensures that during operation, the specific diffraction patterns and energy distribution states generated by each independent diffraction functional region 101 are not interfered with by other functional regions, avoiding deviations of the shaped beam parameters from the preset target due to interactions between functional regions, and guaranteeing the accuracy and independence of the shaping effect of each functional region; when the optical path adjustment mechanism 2 switches between different functional regions to align with the incident laser, a stable shaped beam corresponding to that functional region can be directly obtained without additional correction of interference factors, improving the shaping accuracy and reliability of the dynamic beam shaping module.

[0047] In addition to the features of the above embodiments, this embodiment further specifies that: the etching depth of the surface micro / nano relief structure is designed based on a reverse iterative algorithm, which solves the problem based on the phase and amplitude distribution of the input beam and the target output beam. The laser beam with the first energy distribution characteristic includes, but is not limited to, any one of Gaussian beams, vortex beams, Bessel beams, ring beams, uniform beams, and point-ring beams; it is not uniquely limited here. The first shape specifically includes, but is not limited to, any one of circles, rectangles, squares, ellipses, and straight lines; it is not uniquely limited here. The target output beam type specifically includes any one of Gaussian beams, uniform beams, vortex beams, Bessel beams, ring beams, and point-ring beams; it is not uniquely limited here. The specific selection of all the above parameters can be made according to the specific optical path structure design requirements. The etching depth of the surface micro / nano relief structure is designed based on a reverse iterative algorithm. The algorithm solves the problem based on the phase and amplitude distribution of the input and target output beams, ensuring that the micro / nano relief structure can accurately adjust the wavefront phase and amplitude of the laser beam. This reliably reconstructs the spatial energy distribution characteristics of the laser beam, ensuring that the shaping effect is consistent with the preset target. The algorithm clearly defines various types and shapes of the input and target output beams, covering common beam types and shapes in laser powder bed melting applications. This allows the dynamic beam shaping module to flexibly select parameters according to specific optical path structure design requirements, adapting to various shaping scenarios without the need for additional custom structures, significantly broadening the module's applicability.

[0048] In addition to the features of the above embodiments, this embodiment further specifies that: the optical path adjustment mechanism 2 can respond to the beam shaping control system commands in real time, and change the incident position of the laser beam on the surface of the diffractive optical element 1 according to a preset motion trajectory, that is, switch the laser beam incident on different independent diffraction functional areas 101 on the surface of the diffractive optical element 1 to achieve dynamic laser beam shaping. The optical path adjustment mechanism 2 can respond to the commands of the beam shaping control system in real time, ensuring that the module can promptly execute the shaping function switching according to external control requirements, improving the timeliness of response to dynamic shaping requirements; by changing the incident position of the laser on the surface of the diffractive optical element 1 according to a preset motion trajectory, the switching to different independent diffraction functional areas 101 is realized, ensuring the orderliness and accuracy of the switching process, avoiding switching errors caused by disordered motion trajectories, thereby reliably realizing dynamic laser beam shaping, and improving the control flexibility and switching reliability of the module.

[0049] In addition to the features of the above embodiments, this embodiment further specifies that: the beam expander 3 can respond to the beam shaping control system commands in real time, and dynamically adjust the parameters of the laser beam diameter and divergence angle according to the preset target beam's independent diffraction functional area 101 by changing the relative position of the internal lens group. The adjustment of the divergence angle must ultimately meet the position requirements of the focal plane of the shaped focusing spot, thereby obtaining better beam shaping quality. The beam expander 3 responds to the beam shaping control system commands in real time, and can adjust the laser beam diameter and divergence angle in a timely manner according to the parameter requirements of different independent diffraction functional areas 101, ensuring that the laser parameters incident on each functional area always meet the shaping requirements of the functional area, avoiding deviations in shaping effect caused by parameter mismatch; at the same time, by adjusting the divergence angle to meet the position requirements of the focal plane of the shaped focusing spot, it ensures that the focused spot can accurately fall on the target plane, further optimizing the quality of the shaped beam, and providing a high-quality beam foundation for the accurate melting of metal powder in the subsequent laser powder bed melting process.

[0050] In addition to the features of the above embodiments, this embodiment further specifies that: the beam expander 3 is an electrically operated continuously variable beam expander. The beam expander 3 uses optical materials and coatings with a high damage threshold. Preferably, the beam expander 3 is a 1-3X electrically operated continuously variable beam expander made of ultraviolet fused silica material, with a damage threshold ≥0.5MW / cm. 2 The beam expander 3 employs an electrically operated continuously variable magnification type, enabling continuous and stepless adjustment of the laser beam incident diameter and divergence angle. Compared to a fixed-magnification beam expander, it can more accurately adapt to the parameter requirements of different independent diffraction functional regions 101, improving the flexibility of parameter adjustment. High-damage-threshold optical materials and coatings are used, especially the preferred ultraviolet fused silica material. (1-3X electrically operated continuously variable magnification beam expander (damage threshold ≥ 0.5MW / cm)) 2 It can effectively resist the irradiation of high-power lasers, prevent the beam expander 3 from being damaged due to excessive laser energy, extend the service life of the beam expander 3, and at the same time ensure the stability of beam expansion performance in high-power scenarios, and improve the adaptability of the dynamic beam shaping module to high-power laser applications.

[0051] In addition to the features of the above embodiments, this embodiment further specifies that: the optical elements involved in the diffractive optical element 1 and the optical path adjustment mechanism 2 are typically mounted using an optical adjustment frame. The optical adjustment frame is used to precisely adjust the spatial position of each optical element in the optical path system to ensure the coaxiality of the entire optical path structure. The optical elements of the diffractive optical element 1 and the optical path adjustment mechanism 2 are mounted using an optical adjustment frame. The optical adjustment frame can finely adjust the spatial position of each element, effectively correcting positional deviations generated during installation. By precisely adjusting the position of each element, the coaxiality of the entire optical path structure is ensured, preventing the laser beam from deviating from the preset optical path and incident on non-target areas due to poor coaxiality. This ensures that the laser beam can accurately incident on the target independent diffraction functional area 101, improving the optical path stability and shaping accuracy of the dynamic beam shaping module.

[0052] like Figure 2 As shown in (a), in a first possible example, in addition to the features of the above embodiments, this embodiment further defines that all independent diffraction functional regions 101 include a first diffraction functional region 1011A that shapes a circular Gaussian spot into a circular uniform spot, a second diffraction functional region 1012A that shapes a circular Gaussian spot into a square uniform spot, and a third diffraction functional region 1013A that shapes a circular Gaussian spot into an annular spot. At this time, the first energy distribution feature is a Gaussian spot, the first shape is circular, and the optical path adjustment mechanism 2 changes the laser beam on the diffraction optical element 1 according to a preset motion trajectory, thereby dynamically outputting a circular uniform spot, a square uniform spot, or an annular spot.

[0053] like Figure 2 As shown in (b), in the second possible example, in addition to the features of the above embodiments, this embodiment further defines that: all independent diffraction functional regions 101 include a first diffraction functional region 1011B that shapes a rectangular uniform light spot into an elliptical uniform light spot and a second diffraction functional region 1012B that shapes a rectangular uniform light spot into a square Gaussian light spot.

[0054] like Figure 2 As shown in (c), in the third possible example, in addition to the features of the above embodiments, this embodiment further defines that: all independent diffraction functional regions 101 include a first diffraction functional region 1011C that shapes a circular Gaussian spot into a circular Bessel spot, a second diffraction functional region 1012C that shapes a circular Gaussian spot into a square Bessel spot, a third diffraction functional region 1013B that shapes a circular Gaussian spot into an elliptical uniform spot, and a fourth diffraction functional region 1014A that shapes a circular Gaussian spot into an annular spot.

[0055] like Figure 2As shown in (d), in the fourth possible example, in addition to the features of the above embodiments, this embodiment further defines that: all independent diffraction functional regions 101 include a first diffraction functional region 1011D that shapes a circular uniform light spot into a circular Gaussian light spot, a second diffraction functional region 1012D that shapes a circular uniform light spot into a square uniform light spot, and a third diffraction functional region 1013C that shapes a circular uniform light spot into an annular light spot.

[0056] like Figure 2 As shown in (e), in the fifth possible example, in addition to the features of the above embodiments, this embodiment further defines that: all independent diffraction functional regions 101 include a first diffraction functional region 1011E that shapes a circular Gaussian spot into a circular Bessel spot, a second diffraction functional region 1012E that shapes a circular Gaussian spot into a square Bessel spot, a third diffraction functional region 1013D that shapes a circular Gaussian spot into an elliptical uniform spot, and a fourth diffraction functional region 1014B that shapes a circular Gaussian spot into an annular spot.

[0057] like Figure 2 As shown in (f), in the sixth possible example, in addition to the features of the above embodiments, this embodiment further defines that: all independent diffraction functional regions 101 include a first diffraction functional region 1011F that shapes a circular uniform light spot into a circular Gaussian light spot, a second diffraction functional region 1012F that shapes a circular uniform light spot into a square uniform light spot, and a third diffraction functional region 1013E that shapes a circular uniform light spot into a square uniform light spot.

[0058] The specific shaping functions of the independent diffraction functional regions 101 of the diffractive optical element 1 under different scenarios are clearly defined, covering the shaping of various input light spots such as circular Gaussian, rectangular uniform, and circular uniform. It can output various target light spots such as circular uniform, square uniform, annular, circular Bessel, square Bessel, and elliptical uniform. Furthermore, through the first diffraction functional regions 1011A / 1011B / 1011C / 1011D / 1011E / 1011F and the second diffraction functional regions 1012A / 1012B / 1012C / 1012D / 1012... The clear division of the E / 1012F, the third diffraction functional region 1013A / 1013B / 1013C / 1013E, and the fourth diffraction functional region 1014A / 1014B makes the shaping targets of each functional region clearly identifiable. This multi-input, multi-output shaping function coverage can accurately match the differentiated requirements for spot shape and energy distribution at different forming stages during the laser powder bed melting process. It can achieve the switching of multiple key spots without replacing the diffraction optical element 1, significantly improving the functionality, practicality, and scene adaptability of the dynamic beam shaping module.

[0059] In some embodiments, such as Figure 2As shown, the shape design parameters of the independent diffraction functional area 101 are set to fan-shaped, circular, fan-ring, or rectangular (but not square or square). Optionally, when the shape of the independent diffraction functional area 101 is set to fan-shaped, circular, or fan-ring, the optical path adjustment mechanism 2 drives the diffraction optical element 1 to rotate. Optionally, when the shape of the independent diffraction functional area 101 is set to rectangular (but not square), square, or circular, the optical path adjustment mechanism 2 drives the diffraction optical element 1 to perform linear translation. By clarifying the various shape design parameters of the independent diffraction functional area 101 and establishing the adaptation relationship between the shape and the motion type of the optical path adjustment mechanism 2, it is ensured that the structural design of the diffraction optical element 1 matches the motion mode of the optical path adjustment mechanism 2, avoiding difficulties in switching functional areas due to incompatibility between shape and motion type. This adaptation design enables the optical path adjustment mechanism 2 to drive the diffraction optical element 1 more efficiently and accurately, ensuring that the laser beam can be quickly aligned with the target functional area, improving the structural compatibility and motion switching efficiency of the dynamic beam shaping module.

[0060] In some embodiments, different independent diffraction functional regions 101 have equal or unequal areas. This choice of area design allows the diffraction optical element 1 to adapt to different energy utilization requirements and modulation scenarios, improving the design flexibility of the dynamic beam shaping module. Specifically, when different independent diffraction functional regions 101 have equal areas, it ensures consistent energy utilization across different beam modes. The equal area design ensures that the effective area of ​​the laser beam within the functional region is consistent across different beam modes, avoiding reduced energy utilization in some modes due to area differences and ensuring energy stability of the beam after shaping in each mode. Specifically, when different independent diffraction functional regions 101 have unequal areas, it is used in scenarios requiring a larger modulation area in a specific mode. The unequal area design addresses the need for a larger modulation area in a specific mode by increasing the area of ​​the corresponding functional region to enhance modulation capability, avoiding limited shaping effects due to insufficient area.

[0061] In some embodiments, the partitioning position relationship of the independent diffraction functional regions 101 is set to either discrete or continuous variation. Two designs for the partitioning position relationship of the independent diffraction functional regions 101 are provided according to the target beam mode switching requirements, and matched with corresponding application scenarios. Specifically, when the partitioning position relationship of the independent diffraction functional regions 101 is set to discrete variation, it is suitable for instantaneous beam mode switching scenarios. The discrete variation design makes the positions of each functional region independent, allowing a direct jump from one functional region to another during switching without intermediate transition states. This is suitable for scenarios requiring rapid switching of beam spot modes in laser powder bed melting, improving switching speed. Specifically, when the partitioning position relationship of the independent diffraction functional regions 101 is set to continuous variation, it is suitable for scenarios with gradual transitions in beam modes. The continuous variation design makes the functional region positions gradually distributed, enabling a smooth transition of beam modes during switching. This avoids the impact of sudden energy changes caused by instantaneous switching on the formed part, and is suitable for scenarios with high requirements for mode switching stability.

[0062] In some embodiments, the design parameters for the partitioning arrangement of all independent diffraction functional regions 101 are set to a concentric ring distribution (see [reference]). Figure 2 (f)), sector array distribution (see Figure 2 (a)) or linear arrays (see Figure 2 (d) Specifically, when the partition positions of the independent diffraction functional regions 101 are arranged in a concentric ring distribution or a fan-shaped array distribution, they are adapted to rotational motion trajectories and angle switching scenarios. Optionally, when the partition positions of the independent diffraction functional regions 101 are arranged in a fan-shaped array distribution, they are specifically used for fixed-axis rotation mechanisms; when the partition positions of the independent diffraction functional regions 101 are arranged in a linear array, they are adapted to linear translational motion trajectories and single-direction changes in the light spot. The three arrangement rules for the independent diffraction functional area 101 are clearly defined, and the adaptation relationship between the arrangement rules and the motion trajectory and mechanism type is established: the concentric ring / fan array distribution is adapted to the rotational motion trajectory and angle switching scenario, and the fan array is specifically used for the fixed-axis rotation mechanism to ensure that each functional area can be aligned with the incident laser in sequence with the fixed center as the center during rotational motion, thereby improving the accuracy of rotational switching; the linear array distribution is adapted to the linear translational motion trajectory and the single-direction change of the light spot scenario, ensuring that the switching direction of the functional area is consistent with the changing direction of the light spot during translational motion, and avoiding misalignment between the motion direction and the light spot requirement; this adaptation design makes the structural arrangement of the diffraction optical element 1 highly consistent with the motion trajectory, thereby improving the efficiency and accuracy of functional area switching.

[0063] like Figure 3 , Figure 4 and Figure 5As shown, in addition to the features of the above embodiments, this embodiment further defines that the motion trajectory of the diffractive optical element 1 is linear linear motion, rotational motion, or a combination of linear and rotational motion. Specifically, the optical path adjustment mechanism 2 includes a stepper motor 21, a sensor 22, and an electric component. The stepper motor 21 drives the electric component, and the sensor 22 is used to detect the position or angle of the electric component. Three motion trajectories for the diffractive optical element 1 are provided, which can be flexibly selected according to the arrangement of different independent diffraction functional areas 101, covering most functional area arrangement scenarios and improving motion flexibility. The stepper motor 21 of the optical path adjustment mechanism 2 provides stable power to the electric component, ensuring sufficient and controllable motion driving force. The sensor 22 is used to detect the position or angle of the electric component, which can monitor the motion state of the electric component in real time and feed the information back to the control system to correct motion deviations in a timely manner, avoiding positional shifts caused by stepper motor 21 step loss, mechanical backlash, etc., and improving the accuracy and reliability of the motion of the diffractive optical element 1.

[0064] In addition to the features of the above embodiments, this embodiment further defines that: the motion path of the optical path adjustment mechanism 2 driving the diffractive optical element 1 follows the principle of prioritizing main functions and minimizing travel. The principle of "prioritizing main functions" ensures that the independent diffraction functional area 101 corresponding to the key beam shaping function commonly used in the laser powder bed melting process can be called first, reducing the switching waiting time of key functions and improving forming efficiency; the principle of "minimizing travel" shortens the movement distance of the diffractive optical element 1 between different functional areas by optimizing the motion path, reducing switching time, further improving the dynamic switching speed, while reducing the energy consumption and mechanical wear of the stepper motor 21, extending the service life of the optical path adjustment mechanism 2, and achieving a balance between efficiency and economy.

[0065] In addition to the features of the above embodiments, this embodiment further specifies that: the optical path adjustment mechanism 2 can respond in real time to the motion control commands of the beam shaping control system to achieve dynamic switching of the laser beam incident on the target functional area position of the diffractive optical element 1, ensuring timely execution of the target functional area switching task, avoiding disruption of the forming rhythm due to response delay, and improving the timeliness of dynamic shaping requirements. The high precision indicators of the optical path adjustment mechanism 2, with repeatability positioning accuracy ≤0.004° and positioning resolution ≤0.0005°, ensure that the diffractive optical element 1 can accurately return to or reach the target functional area position after each switching, avoiding laser beam incident on the edge of the functional area or non-target area due to positioning deviation, thereby ensuring the consistency and stability of the shaping effect and providing a guarantee for the high precision requirements of laser powder bed melting forming.

[0066] In addition to the features of the above embodiments, this embodiment further specifies that: the stepper motor 21 can be an absolute system stepper motor, which can directly determine the current position without relying on initial position calibration, avoiding position loss caused by power failure or missed steps in traditional incremental motors, improving the convenience and accuracy of position detection, thereby achieving precise adjustment of optical path calibration. The single-step resolution of the stepper motor 21 is ≤0.036°, ensuring that the motor can achieve fine movements of small angles, meeting the accuracy requirements of small-pitch switching of the independent diffraction functional area 101. Optionally, a backlash-free harmonic reducer can be equipped, with a reduction ratio range between 50:1 and 100:1, which can effectively eliminate mechanical transmission backlash, improve motor output torque and motion accuracy, further optimize the accuracy of optical path calibration, and provide power guarantee for the high-precision movement of the diffraction optical element 1.

[0067] like Figure 1 , Figure 3 , Figure 4 and Figure 5 As shown, in addition to the features of the above embodiments, this embodiment further specifies that: the dynamic beam shaping module 2 adopts a modular design concept in the installation of the optical path system. During optical component maintenance or optical path improvement, the corresponding optical components can be quickly disassembled and replaced, meeting the dynamic beam shaping requirements of different laser additive manufacturing optical path structures. Compared with traditional laser beam shaping solutions, the dynamic beam shaping module provided in this application increases application flexibility and versatility. The connection between the diffractive optical element 1 and the optical path adjustment mechanism 2 can be achieved through integrated packaging or separate packaging. The modular design of the dynamic beam shaping module allows components such as the diffractive optical element 1, the optical path adjustment mechanism 2, and the beam expander 3 to be independently disassembled and installed. During optical component maintenance or optical path improvement, it is not necessary to disassemble the entire module or optical path system, significantly shortening maintenance and improvement time and reducing operational difficulty. The modular design enables the module to adapt to the installation requirements of different laser additive manufacturing optical path structures, avoiding incompatibility due to differences in optical path structures and improving application versatility. The diffractive optical element 1 and the optical path adjustment mechanism 2 can be packaged in an integrated or separate manner, which can be flexibly selected according to the installation space size and maintenance convenience requirements, further enhancing the application flexibility of the module.

[0068] like Figure 2 (c) and Figure 3As shown, in addition to the features of the above embodiments, this embodiment further specifies that: the connection between the diffractive optical element 1 and the optical path adjustment mechanism 2 is an integral package, and the surface of the diffractive optical element 1 is etched with multiple independent diffraction functional regions 101 that are discretely varied and distributed around the center of the diffractive optical element 1. Optionally, the diffractive optical element 1 adopts a circular substrate, and the number of independent diffraction functional regions 101 is four, with a circular shape and equal area. The electric component is an electric rotation component 23, which drives the diffractive optical element 1 to be rotatably arranged around the center of the diffractive optical element 1. Specifically, the electric rotating assembly 23 includes a transmission worm 231, a transmission worm wheel 232, and a transmission pin 233. The transmission pin 233 is connected to the diffractive optical element 1 and the transmission worm wheel 232, respectively. The transmission worm 231 is connected to the stepper motor 21 and the transmission worm wheel 232, respectively. The transmission worm wheel 232 rotates around the center of the diffractive optical element 1. The stepper motor 21 drives the transmission worm 231 to rotate, which in turn drives the transmission worm wheel 232, thereby causing the transmission pin 233 and the diffractive optical element 1 to rotate accordingly. Further, a bearing through hole 102 is provided at the center of the diffractive optical element 1. The electric rotating assembly 23 includes a first bearing 234, which is installed in the bearing through hole 102. The first bearing 234 cooperates with the transmission worm wheel 232 through the bearing through hole 102 to form a rotating pair. The diffractive optical element 1 is rotatably supported on the first bearing 234. The rotation direction and rotation angle of the diffractive optical element 1 are dynamically responded to by control commands issued by the beam shaping control system. Optionally, the transmission worm gear 232 has a first through hole and a first retaining ring adapted to the first through hole. The first retaining ring axially fixes the diffractive optical element 1, restricting its axial movement. Further, the first retaining ring is fixedly disposed on the wall of the first through hole, for example, by threading it to the wall of the first through hole. The diffractive optical element 1 is located at the first retaining ring, and the first retaining ring abuts against both sides of the diffractive optical element 1 in the thickness direction, thereby restricting its axial movement. In one example, the transmission worm gear 232 has first grooves arranged at equal angular intervals on its surface. The sensor 22 is a rotation angle infrared sensor. The sensor 22 detects the angle of the transmission worm gear 232 through the first groove to control the motion accuracy of the optical path adjustment mechanism 2. The repeatability accuracy is ≤0.004°. The diffractive optical element 1, the optical path adjustment mechanism 2, and the beam expander 3 are integrally encapsulated in a closed housing. Standard connecting flanges are provided at both ends of the housing. The standard connecting flanges are used to detachably install the dynamic beam shaping module to the laser powder bed melting shaping optical path system. An optical window can be designed on the side of the housing for connecting an external coaxial monitoring system to monitor the changes in the characteristic state of the shaping laser beam during spatial propagation in real time.

[0069] The diffractive optical element 1 and the optical path adjustment mechanism 2 are integrated into a compact package, reducing the connection gap between components and improving overall stability. The transmission worm gear 232, in conjunction with the first bearing 234, forms a rotating pair, ensuring smooth and uninterrupted rotation of the diffractive optical element 1 and preventing spot deviation during rotation. The sensor 22 detects the angle of the transmission worm gear 232 through the first groove, enabling real-time detection of the rotation angle and ensuring a repeatability accuracy of ≤0.004°, guaranteeing the precision of functional area switching. The integrated enclosed housing protects the internal components from dust and vibration interference. The standard connecting flange facilitates the detachable installation of the dynamic beam shaping module and the laser powder bed melting shaping optical path system. The side optical window supports the connection of an external coaxial monitoring system, enabling real-time monitoring of laser beam propagation characteristics, timely detection of shaping anomalies, and improved reliability, installation convenience, and monitoring capabilities of the dynamic beam shaping module.

[0070] like Figure 2 (d) and Figure 4As shown, in addition to the features of the above embodiments, this embodiment further specifies that: the connection between the diffractive optical element 1 and the optical path adjustment mechanism 2 is an integral package, and the surface of the diffractive optical element 1 is etched with a plurality of continuously varying independent diffractive functional regions 101 distributed along a preset straight line. Optionally, the diffractive optical element 1 adopts a rectangular substrate, and the number of independent diffractive functional regions 101 is three, the shape is rectangular, and the area is equal. The electric component is an electric displacement component 24, which drives the diffractive optical element 1 to perform reciprocating linear motion along the preset straight line. Specifically, the electric displacement assembly 24 includes a diffractive optical element fixing platform 241, a transmission rack 242, and a transmission gear 243. The diffractive optical element 1 is fixed to the diffractive optical element fixing platform 241 by means of a clamping structure, etc. The diffractive optical element fixing platform 241 is fixed to the transmission rack 242 by means of threads, etc. The length direction of the transmission rack 242 is consistent with the preset straight line direction. The side of the transmission rack 242 away from the diffractive optical element fixing platform 241 is connected to the transmission gear 243. The transmission rack 242 and the transmission gear 243 cooperate to form a kinematic pair, which can realize the linear translational movement of the diffractive optical element 1. The movement direction and movement distance of the diffractive optical element 1 are dynamically responded to by the control commands issued by the beam shaping control system. The transmission rack 242 has second grooves arranged at equal intervals on its surface. The sensor 22 is a position sensor. The sensor 22 detects the position of the transmission rack 242 through the second grooves to control the motion accuracy of the optical path adjustment mechanism 2. The repeatability accuracy is ≤0.004°. The diffractive optical element 1, the optical path adjustment mechanism 2 and the beam expander 3 are integrated and encapsulated in a closed housing. Standard connecting flanges are provided at both ends of the housing. The standard connecting flanges are used to detachably install the dynamic beam shaping module to the laser powder bed melting shaping optical path system. An optical window can be designed on the side of the housing for connecting an external coaxial monitoring system to monitor the changes in the characteristic state of the shaping laser beam in real time during its spatial propagation.

[0071] The diffractive optical element 1 and the optical path adjustment mechanism 2 are integrated into a single package, making them suitable for linear translational motion scenarios. The rectangular structure facilitates installation in narrow optical path spaces. The kinematic pair formed by the transmission rack 242 and the transmission gear 243 provides smooth transmission and controllable stroke. Combined with the diffractive optical element fixing platform 241 fixed by the clamp structure, it ensures accurate and secure linear translational motion of the diffractive optical element 1, preventing functional area position shift during translation. The sensor 22 detects the position of the transmission rack 242 through the second groove, enabling real-time detection of the translational position and ensuring a repeatability accuracy of ≤0.004°, guaranteeing the accuracy of functional area switching. The integrated enclosed housing, standard connecting flange, and side optical window design protect the components, facilitate installation, and support real-time monitoring, improving the adaptability and practicality of the dynamic beam shaping module for linear translational scenarios.

[0072] like Figure 2 (f) and Figure 5As shown, in addition to the features of the above embodiments, this embodiment further specifies that: the connection between the diffractive optical element 1 and the optical path adjustment mechanism 2 adopts a split-package design, and the surface of the diffractive optical element 1 is etched with multiple independent diffractive functional regions 101 distributed along the same annular band. Optionally, the diffractive optical element 1 adopts a hollow annular substrate, and the independent diffractive functional regions 101 are continuously varied, with three regions of equal area in a fan-shaped annular form. The electric component is an electric rotating component 23, and the optical path adjustment mechanism 2 also includes a reflector assembly 25, which has a reflector for guiding the incident light beam toward different independent diffractive functional regions 101. The electric rotating component 23 drives the reflector assembly 25 to rotate, thereby rotating the reflector assembly 25 to different angles to guide the incident light beam toward different independent diffractive functional regions 101. Specifically, the reflector assembly 25 includes a first reflector group 251, a first reflector group mounting component 252, a second reflector group 253, a second reflector group mounting component 254, a first reflector 255, and a second reflector 256. The first reflector group 251 is fixedly connected to the first reflector group mounting component 252 by screws or other means. The first reflector group 251 includes a third reflector 2511, a fourth reflector 2512, and a fifth reflector 2513 arranged at equal intervals. The second reflector group 253 is fixedly connected to the second reflector group mounting component 254 by screws or other means. The second reflector group 253 includes a sixth reflector 2531, a seventh reflector 2532, and an eighth reflector 2533 arranged at equal intervals. The first reflector 255 and the second reflector 256 are respectively disposed at both ends of the diffractive optical element 1. Specifically, the output shaft of the electric rotating assembly 23 is connected to a rotating shaft 236, and the first reflector 255 and the second reflector 256 are fixedly connected to the rotating shaft 236 by means of threads or other means. Optionally, the rotating shaft 236 is movably inserted through the hollow through hole of the diffractive optical element 1, and the length direction of the rotating shaft 236 is consistent with the central axis of the annular belt.The first reflector 255 and the second reflector 256 are arranged in a mirror symmetrical manner with respect to the diffractive optical element 1. The first reflector 255 is at least partially opposite to the first reflector group 251, and the second reflector 256 is at least partially opposite to the second reflector group 253. The first reflector 255 and the second reflector 256 are driven to rotate by the rotating shaft 236. The rotation direction and rotation angle of the first reflector 255 and the second reflector 256 are dynamically responded to by control commands issued by the beam shaping control system. Specifically, the surfaces of the first reflector group mounting parts 252 and 254 are both machined with third grooves arranged at equal angles. The sensor 22 is a rotation angle infrared sensor. The sensor 22 detects the angle of the first reflector group mounting parts 252 and 254 through the third grooves to control the movement accuracy of the optical path adjustment mechanism 2. Specifically, the electric rotating assembly 23 includes a diffractive optical element fixing part 235. The diffractive optical element 1 is fixedly connected to the diffractive optical element fixing part 235 by means of positioning pins, etc., to achieve radial limiting. Optionally, a first baffle is fixedly mounted on the diffractive optical element fixing member 235, and the first baffle axially fixes the diffractive optical element 1. Figure 5 In one possible example shown, the diffractive optical element fixing component 235 is fixedly sleeved onto the diffractive optical element 1 to achieve circumferential limiting. The first baffle is fixed to the diffractive optical element fixing component 235 by means of threads or other methods, and protrudes from the axial direction of the diffractive optical element 1 to limit its axial movement. The diffractive optical element 1, the optical path adjustment mechanism 2, and the beam expander 3 are integrally encapsulated in a closed housing. Standard connecting flanges are provided at both ends of the housing. The standard connecting flanges are used to detachably install the dynamic beam shaping module to the laser powder bed melting shaping optical path system. An optical window can be designed on the side of the housing for connecting an external coaxial monitoring system to monitor the changes in the characteristic state of the shaping laser beam during spatial propagation in real time.

[0073] Furthermore, the first reflector 255, the third reflector 2511, the second reflector 256, and the sixth reflector 2531, together with the first diffraction functional area 1011 etched on the surface of the diffraction optical element 1, form a first adjustment optical path; the first reflector 255, the fourth reflector 2512, the second reflector 256, and the seventh reflector 2532, together with the second diffraction functional area 1012 etched on the surface of the diffraction optical element 1, form a second adjustment optical path; and the first reflector 255, the fifth reflector 2513, the second reflector 256, and the eighth reflector 2533, together with the third diffraction functional area 1013 etched on the surface of the diffraction optical element 1, form a third adjustment optical path.

[0074] The diffractive optical element 1 and the optical path adjustment mechanism 2 are packaged separately. The separate design reduces the installation difficulty of large components. At the same time, the axial fixing method of the positioning pin and the first baffle ensures that the diffractive optical element 1 is installed firmly and avoids loosening during rotation. The multiple mirrors of the mirror assembly 25 and the different independent diffraction functional areas 101 form three adjustable optical paths, which can realize the simultaneous shaping of multiple beams or the rapid switching of multi-optical path shaping, improve the shaping efficiency, and adapt to the needs of simultaneous shaping of multiple areas in laser powder bed melting. The sensor 22 can detect the rotation angle of the mirror in real time through the third groove set on the first mirror assembly mounting and the second mirror assembly mounting, ensuring the accuracy of optical path switching. The design of the integrated closed shell, standard connecting flange and side optical window also realizes the functions of component protection, convenient installation and real-time monitoring. The separate packaging combined with the multi-optical path design significantly improves the module's adaptability to complex optical path scenarios and shaping efficiency.

[0075] In some embodiments, the material of the light-transmitting substrate 11 is one of fused silica, sapphire, ZnSe, and plastic. The light-transmitting substrate 11 offers four material options: fused silica, sapphire, ZnSe, and plastic. Different materials have different core characteristics, allowing for flexible selection of the appropriate material based on the actual application scenario of the dynamic beam shaping module. This avoids the problem that a single material cannot meet the needs of multiple scenarios, significantly improving the scenario adaptability of the light-transmitting substrate 11 and the entire diffractive optical element 1.

[0076] In some embodiments, the thickness of the transparent substrate 11 is 1mm-10mm. The adjustable range of 1mm-10mm thickness of the transparent substrate 11 can be flexibly adjusted according to the overall size of the diffractive optical element 1, the processing requirements of the micro-nano relief structure, and the space constraints of the optical path system, avoiding the structural design limitations caused by a fixed thickness; a thickness of 3mm is preferred, which takes into account both the structural strength and optical performance of the substrate, and can be directly adapted in most laser powder bed melting optical path scenarios, reducing the cost of customized design and improving the versatility of the substrate.

[0077] In some embodiments, the transmission band of the transparent substrate 11 is 193nm-1080nm. The transmission band of the transparent substrate 11 covers 193nm to 1080nm, which is the wavelength range of lasers commonly used in laser powder bed melting. This ensures that the laser beam incident on the diffractive optical element 1 can efficiently pass through the substrate to reach the independent diffraction functional region 101, avoiding laser energy loss due to band mismatch, ensuring the energy stability of the laser beam before shaping, and laying the energy foundation for the subsequent precise adjustment of the wavefront phase and amplitude of the independent diffraction functional region 101.

[0078] In some embodiments, the surface of the light-transmitting substrate 11 is provided with a specified wavelength antireflection film to ensure that the transmittance of the laser beam in the specified wavelength is ≥99.8%. The specified wavelength antireflection film on the surface of the light-transmitting substrate 11 can significantly reduce the reflection loss of the laser beam on the substrate surface, so that the transmittance of the specified wavelength is ≥99.8%, maximizing the retention of laser energy, while avoiding interference of reflected light with the subsequent optical path, ensuring that the laser beam is incident on the independent diffraction functional region 101 with high energy utilization and low interference, thereby improving the energy utilization efficiency and optical path stability of the dynamic beam shaping module.

[0079] In some embodiments, the laser damage threshold of the transparent substrate 11 should meet the requirements of a 500W-5000W laser, and can be selected according to the optical path requirements, typically ≥5KJ / cm². 2 The diffraction efficiency is ≥98%. The laser damage threshold of the transparent substrate 11 meets the requirements of 500W-5000W lasers, and can be adapted to different power scenarios in laser powder bed melting, from low-power fine forming to high-power rapid forming. This avoids substrate ablation and cracking due to excessive laser power, and extends the service life of the diffraction optical element 1. The diffraction efficiency of ≥98% ensures that after the laser beam is shaped by the independent diffraction functional area 101, most of the energy can be converted into the target output beam, reducing diffraction loss and ensuring that the energy density of the shaped beam meets the requirements of metal powder melting, thereby improving the energy utilization efficiency and forming reliability of the module.

[0080] Example 2

[0081] like Figure 2As shown in (a), in addition to the features of the above embodiments, this embodiment further specifies that: the light-transmitting substrate 11 of the diffractive optical element 1 is a circular substrate made of fused silica material with a thickness of 5 mm, and the independent diffraction functional regions 101 on the surface are set as three continuously varying fan-shaped areas with equal areas. The specific functions of each independent diffraction functional region 101 are respectively set as a first diffraction functional region 1011A that shapes a circular Gaussian spot into a circular uniform spot, a second diffraction functional region 1012A that shapes a circular Gaussian spot into a square uniform spot, and a third diffraction functional region 1013A that shapes a circular Gaussian spot into an annular spot; the optical path adjustment mechanism 2 controls the trajectory of the incident laser beam on the surface of the diffractive optical element 1 to be set as an equilateral triangle. The movement path, with its three vertices (A1, B1, C1) located in the central regions of three independent diffraction functional regions 101, should ensure that the laser beam spot is completely covered by the target independent diffraction functional region 101 before shaping when it moves to the vertices. Specifically, based on the principle of minimum switching travel, the movement trajectory should include linear translational motion of vertices A1 and B1 and linear translational motion of vertices A1, B1, and C1, where any vertex can be used as the starting point. Based on the principle of prioritizing motion function, the optical path adjustment mechanism 2 may optionally adopt a fixed-axis rotational motion module, in which case the movement trajectory should be a fixed-axis rotational motion of vertices A1 and B1 and a fixed-axis rotational motion of vertices A1, B1, and C1, where any vertex can be used as the starting point.

[0082] The diffractive optical element 1 uses a fused silica circular substrate (5mm thick) to adapt to the circular light spot incident scenarios commonly used in laser powder bed melting. The high transmittance and stability of fused silica ensure optical performance. Three continuous equal-area fan-shaped independent diffraction functional areas 101 enable the switching from a circular Gaussian light spot to a circular uniform, square uniform, and annular light spot, covering the core requirements of contour scanning and filling scanning. The equilateral triangular translation path of the optical path adjustment mechanism 2 ensures that the laser spot completely covers the target functional area, avoiding shaping deviations caused by edge incident. The minimum switching stroke principle shortens the movement distance and improves the switching speed. The motion function priority principle supports the adaptation of fixed-axis rotation modules, increasing the flexibility of the movement mode and ensuring efficient switching of functional areas in different installation scenarios.

[0083] like Figure 2As shown in (b), in addition to the features of the above embodiments, this embodiment further specifies that: the light-transmitting substrate 11 of the diffractive optical element 1 is a circular substrate made of sapphire material, and the independent diffraction functional regions 101 are set as two discretely varying fan-shaped areas with unequal areas. The specific functions of each independent diffraction functional region 101 are set as a first diffraction functional region 1011B that shapes a rectangular uniform light spot into an elliptical uniform light spot and a second diffraction functional region 1012B that shapes a rectangular uniform light spot into a square Gaussian light spot; the optical path adjustment mechanism 2 controls the trajectory of the incident laser beam on the surface of the diffractive optical element 1 to be a straight translation path. The two vertices (A2, B2) of this trajectory are located in the central regions of the two independent diffraction functional regions 101, respectively. It should be ensured that when the laser beam moves to the vertex, the light spot before shaping is completely covered by the target independent diffraction functional region 101; specifically, based on the principle of minimum switching stroke, the trajectory includes the linear translational movement of the two vertices A2 and B2; wherein, any vertex can be used as a starting point.

[0084] The light-transmitting substrate 11 is made of sapphire, whose high hardness can resist dust abrasion in the laser powder bed melting environment and extend the life of the diffraction optical element 1. Two discrete unequal area fan-shaped functional areas realize the switching from rectangular uniform light spot to elliptical uniform and square Gaussian light spot. The unequal area design can adapt to the different energy requirements of the two light spots. The straight translation path ensures that the light spot completely covers the target functional area. The principle of minimum switching stroke makes the straight movement distance between A2 and B2 the shortest, which greatly shortens the switching time, improves the dynamic response efficiency, and adapts to the forming scene that needs to switch quickly between the two light spots.

[0085] like Figure 2As shown in (c), in addition to the features of the above embodiments, this embodiment further specifies that: the light-transmitting substrate 11 of the diffractive optical element 1 is a circular substrate made of sapphire material; the independent diffraction functional regions 101 are set as four discretely varying circles with equal areas; the specific functions of each independent diffraction functional region 101 are set as follows: a first diffraction functional region 1011C that shapes a circular Gaussian spot into a circular Bessel spot; a second diffraction functional region 1012C that shapes a circular Gaussian spot into a square Bessel spot; a third diffraction functional region 1013B that shapes a circular Gaussian spot into an elliptical uniform spot; and a fourth diffraction functional region 1014A that shapes a circular Gaussian spot into an annular spot; the optical path adjustment mechanism 2 controls the trajectory of the incident laser beam on the surface of the diffractive optical element 1 to be set as an annular rotation path or a composite linear and rotational motion path. The four path points (A3, B3, C3, D3) of the trajectory are located at the centers of the four independent diffraction functional regions 101, respectively. It should be ensured that when the laser beam moves to the vertex, the pre-shaping spot is completely covered by the target independent diffraction functional region 101. Specifically, based on the principle of prioritizing the function of the motion module, the optical path adjustment mechanism 2 may optionally adopt a fixed-axis rotation motion module, in which case the motion trajectory should be a fixed-axis rotation motion of the two vertices A3 and B3 and a fixed-axis rotation motion of the three vertices A3, B3, and C3 or the four vertices A3, B3, C3, and D3. Alternatively, the optical path adjustment mechanism 2 may optionally adopt a linear translation motion module, in which case the motion trajectory should be a linear translation motion of the two vertices A3 and B3 and a linear translation motion of the three vertices A3, B3, and C3, as well as a linear translation motion of the four vertices A3, B3, C3, and D3. Any vertex can be used as the starting point.

[0086] The sapphire circular substrate combines hardness and stability, making it suitable for long-term use in multi-functional areas. Four discrete, equal-area circular functional areas enable switching between circular Gaussian spots and Bezier (circular / square), elliptical uniform, and annular spots. The non-diffraction characteristics of Bezier spots improve the quality of deep-melt forming, and multiple spot types cover complex forming requirements. Annular rotation or linear-rotation composite motion paths ensure that the spot completely covers the functional areas. The motion module prioritizes functionality and supports fixed-axis rotation or linear translation module adaptation, which can be flexibly selected according to the optical path spatial layout to improve module installation compatibility. At the same time, multi-vertex motion trajectories support switching between some or all functional areas to adapt to different forming process requirements.

[0087] like Figure 2As shown in (d), in addition to the features of the above embodiments, this embodiment further specifies that: the light-transmitting substrate 11 of the diffractive optical element 1 is made of a rectangular substrate liquid crystal polymer material; the independent diffraction functional regions 101 are set as three continuously varying rectangles with equal areas, not squares; the specific functions of each independent diffraction functional region 101 are set as follows: a first diffraction functional region 1011D that shapes a circular uniform light spot into a circular Gaussian light spot; a second diffraction functional region 1012D that shapes a circular uniform light spot into a square uniform light spot; and a third diffraction functional region 1013C that shapes a circular uniform light spot into an annular light spot; optical path The adjustment mechanism 2 controls the trajectory of the incident laser beam on the surface of the diffractive optical element 1 to be a straight translation path. The three vertices (A4, B4, C4) of this trajectory are located in the central regions of the two independent diffraction functional areas 101, respectively. It should be ensured that when the laser beam moves to the vertices, the pre-shaping spot is completely covered by the target independent diffraction functional area 101. Specifically, based on the principle of minimum travel motion, the optical path adjustment mechanism 2 should select a linear translation motion module. The motion trajectory includes the linear translation motion of the two vertices A4 and B4, and the linear translation motion of the two vertices A4 and C4. Any vertex can be used as the starting point.

[0088] The light-transmitting substrate 11 adopts a rectangular liquid crystal polymer substrate, which is lightweight and easy to process into a rectangular and non-square structure, suitable for narrow optical path spaces; three continuous rectangular and non-square functional areas of equal area realize the switching from circular uniform light spot to Gaussian (circular), square uniform, and annular light spot, meet the reverse shaping requirements, and adapt to specific laser output spot types; the linear translation path ensures complete coverage of the light spot, and the linear movement distance between A4 and B4 and between A4 and C4 is the shortest under the principle of minimum travel, reducing switching time. The selection of the linear translation module further simplifies the mechanism structure, reduces costs, and is suitable for cost-sensitive low-to-medium power shaping scenarios.

[0089] like Figure 2As shown in (e), in addition to the features of the above embodiments, this embodiment further specifies that: the light-transmitting substrate 11 of the diffractive optical element 1 is made of ZnSe material with a rectangular substrate; the independent diffraction functional regions 101 are set as four continuously varying squares with equal areas; the specific functions of each independent diffraction functional region 101 are set as follows: a first diffraction functional region 1011E for shaping a circular Gaussian spot into a circular Bessel spot; a second diffraction functional region 1012E for shaping a circular Gaussian spot into a square Bessel spot; a third diffraction functional region 1013D for shaping a circular Gaussian spot into an elliptical uniform spot; and a fourth diffraction functional region 1014B for shaping a circular Gaussian spot into an annular spot; the optical path adjustment mechanism 2 The trajectory of the incident laser beam on the surface of the diffractive optical element 1 is set as a square translation path. The four path points (A5, B5, C5, D5) of this trajectory are located in the central regions of four independent diffraction functional regions 101. It should be ensured that when the laser beam moves to the vertex, the pre-shaping spot is completely covered by the target functional region. Specifically, based on the principle of minimum travel motion, the optical path adjustment mechanism 2 should select a linear translation motion module. The motion trajectory includes linear translation motion of the two vertices A5 and B5, linear translation motion of the two vertices A5 and C5, linear translation motion of the three vertices A5, B5, and C5, and linear translation motion of the four vertices A5, B5, C5, and D5. Any vertex can be used as the starting point.

[0090] The ZnSe rectangular substrate exhibits excellent transmittance in the mid-infrared band, making it suitable for specific mid-infrared laser applications. Four consecutive square functional areas enable the switching between circular Gaussian spots and Bezier (circular / square), elliptical uniform, and annular spots. The continuous square layout facilitates linear translation switching. The square translation path ensures complete spot coverage, and various vertex combinations of motion trajectories can adapt to different forming processes under the principle of minimum travel. The linear translation module simplifies the structure, improves switching efficiency, and meets the multi-spot requirements of mid-infrared laser forming.

[0091] like Figure 2As shown in (f), in addition to the features of the above embodiments, this embodiment further specifies that the light-transmitting substrate 11 of the diffractive optical element 1 is made of ZnSe material with a physically hollow circular ring substrate, and the independent diffraction functional regions 101 are set as three continuously varying concentric fan rings with equal areas. The specific functions of each independent diffraction functional region 101 are set as follows: a first diffraction functional region 1011F that shapes a circular uniform light spot into a circular Gaussian light spot, a second diffraction functional region 1012F that shapes a circular uniform light spot into a square uniform light spot, and a third diffraction functional region 1013E that shapes a circular uniform light spot into a square uniform light spot. In particular, the central region of its light-transmitting substrate 11 can be selectively hollowed out or left unetched, and this position corresponds to the unshaped light-transmitting region. The optical path adjustment mechanism 2 controls the movement of the incident laser beam on the surface of the functionally modulated diffractive optical element 1. The trajectory is set as a composite motion path of circular rotation and linear translation. The three path points (A6, B6, C6) of the circular rotation trajectory and the vertex D6 of the linear translation path are located in the central region of the independent diffraction functional region 101 and the geometric center region of the substrate, respectively. It should be ensured that when the laser beam moves to the vertex, the spot before shaping is completely covered by the independent diffraction functional region 101 of the target. Specifically, based on the principle of prioritizing the function of the motion module, the optical path adjustment mechanism 2 can optionally adopt a fixed-axis rotation motion module, in which case the motion trajectory should be a fixed-axis rotation motion of the two vertices A6 and B6 and a fixed-axis rotation motion of the three vertices A6, B6, and C6. Alternatively, the optical path adjustment mechanism 2 can optionally adopt a linear translation motion module, in which case the motion trajectory should be a linear translation motion of the two vertices A6 and B6 and a linear translation motion of the three vertices A6, B6, and C6. Any vertex can be used as the starting point.

[0092] The ZnSe hollow ring substrate is adapted to an optical path structure with a central rotating shaft. The hollow / unetched light-transmitting area in the center allows the laser to pass directly without shaping, adapting to rapid prototyping stages that do not require shaping and reducing function switching steps. Three continuous concentric fan-shaped functional areas of equal area enable the switching between circular uniform light spots and Gaussian (circular) and square uniform (two types) light spots, meeting the differentiated needs of square light spots. The combined motion path of ring rotation and linear translation ensures that the light spot completely covers the shaping area and the light-transmitting area. The motion module function priority principle supports the adaptation of rotation or translation modules, which can be flexibly selected according to the optical path layout. The integrated design of the light-transmitting area and the shaping area improves the functional integration of the dynamic beam shaping module and reduces the number of optical path components.

[0093] Example 3

[0094] like Figures 1 to 6As shown, this embodiment discloses a laser powder bed melting and shaping optical path system, including a dynamic beam shaping module 100; a laser 200, which emits a collimated beam to the dynamic beam shaping module 100; a scanning galvanometer 300; a field lens 400, which is connected to the scanning galvanometer 300 via a junction ring 500; and a powder bed forming cavity 600, which is positioned opposite to the light outlet of the field lens 400. The beam emitted by the laser 200 passes sequentially through a beam expander 3, a diffractive optical element 1, and the scanning galvanometer 300, and is finally focused by the field lens 400 onto the surface of the forming cylinder inside the powder bed forming cavity 600, thereby completing the layer-by-layer melting and shaping of metal powder according to the quality of the control system.

[0095] The laser powder bed melting and shaping optical path system disclosed in this application employs a modular design approach between the shaping optical path system formed by the laser 200, dynamic beam shaping module 100, scanning galvanometer 300, and field mirror 400, and the powder bed forming cavity 600. During equipment maintenance or upgrades, the optical path module and forming cavity module can be quickly disassembled and replaced via standardized interfaces. This method overcomes the drawbacks of traditional integral welded structures, such as difficult maintenance, the need for complete shutdown for upgrades, and time-consuming component replacements. Compared to traditional integral welded structures or bolted hard-connection solutions, this system, through its modular interface design, achieves high maintainability, flexible expandability, and convenient upgrades, offering greater advantages in production line compatibility and equipment iteration. Furthermore, the modular design facilitates the monitoring of the shaping beam quality and the adjustment of the optical path system.

[0096] In addition to the features of the above embodiments, this embodiment further specifies that: the laser 200 can be selected as a single-mode circular Gaussian laser, a multimode circular uniform light laser, or a multimode circular dot-ring laser; further, the output port of the laser 200 can be a QBH interface or a QCS interface; the QBH interface requires an additional collimator, and the QCS interface is preferred; further, the wavelength range of the laser 200 is 523nm-1080nm; the output power range is 5-5000W; the output beam diameter range is 5-14mm; and the beam quality M... 2 ≤1.2; Generally, commercial laser powder bed melting equipment typically uses a QCS interface, a wavelength of 1064nm, a laser power range of 5-1000W, a beam diameter of 7mm, and a beam quality of M. 2A single-mode circular Gaussian laser with a wavelength of 1.15. Laser 200 offers three types of options: single-mode Gaussian, multimode uniform, and multimode point-ring, to adapt to different forming requirements. The output port can be either QBH or QCS; the preferred QCS interface reduces the number of optical path components, lowering energy loss and installation complexity. The range of parameters for wavelength, power, beam diameter, and beam quality covers low-power fine-tuning to high-power rapid forming scenarios in laser powder bed melting, ensuring that suitable parameters can be found for different forming needs. The clear definition of commonly used commercial parameters allows the system to be directly compatible with mainstream commercial lasers, reducing equipment selection and integration difficulty and improving the feasibility of commercial applications.

[0097] In addition to the features of the above embodiments, this embodiment further specifies that: the diffractive optical element 1, the optical path adjustment mechanism 2, and the beam expander 3 are integrated and packaged in a closed housing; the dynamic beam shaping module 100 is typically packaged using an optical housing; the surface of the optical housing may optionally be provided with an optical window and a standard flange interface; the optical window is used to connect an external coaxial monitoring system to monitor the changes in the characteristic state of the shaping laser beam during spatial propagation in real time; and the standard flange interface allows the dynamic beam shaping module 100 to be detachably installed in a commonly used laser powder bed melting shaping optical path system. The diffractive optical element 1, optical path adjustment mechanism 2, and beam expander 3 are integrated and packaged in a closed housing / optical cover, which can effectively isolate dust and splashes in the laser powder bed melting environment, avoid component contamination or damage, and extend the module's service life. The optical window supports the connection of an external coaxial monitoring system, which can monitor the spatial propagation characteristics of the shaping beam in real time, detect shaping abnormalities in a timely manner, facilitate rapid adjustment, and improve the stability of forming quality. The standard flange interface allows the dynamic beam shaping module 100 to be directly adapted to commonly used laser powder bed melting shaping optical path systems without the need for customized interfaces, enabling quick and easy disassembly and installation, and improving the module's versatility and ease of installation.

[0098] In addition to the features of the above embodiments, this embodiment further specifies that: the dynamic beam shaping module 100 can be optionally directly mounted to the rear end of the scanning galvanometer 300 via a standard flange interface on the housing surface; or, optionally, it can be fixed to the laser powder bed melting and shaping optical path system via an electric translation stage or connector. The dynamic beam shaping module 100 provides two installation methods: one is to be directly mounted to the rear end of the scanning galvanometer 300 via a standard flange interface, which is suitable for scenarios with compact optical path space and no need to adjust the module position, and the installation is quick and the optical path coaxiality is easy to ensure; the other is to be fixed via an electric translation stage or connector, which is suitable for scenarios that require fine adjustment of the module position or flexible optical path spatial layout. The electric translation stage can realize fine position adjustment of the module, and the connector can adapt to different installation structures. The option of two installation methods enables the module to adapt to the spatial layout and installation requirements of different optical path systems, improving installation compatibility.

[0099] In addition to the features of the above embodiments, this embodiment further specifies that: the housing of the dynamic beam shaping module 100 is made of anodized aluminum plate. The use of anodized aluminum plate for the housing of the dynamic beam shaping module 100 allows for the formation of a dense oxide film on the aluminum plate surface, improving the corrosion resistance and wear resistance of the housing and extending its service life. The lightweight aluminum plate reduces the overall weight of the module, lowering the load on the optical path system. Simultaneously, the aluminum plate's good heat dissipation performance helps dissipate the heat generated by the internal components during operation, preventing high temperatures from affecting the performance of the optical components and ensuring long-term stable operation of the module.

[0100] like Figure 1 and Figure 6 As shown, in addition to the features of the above embodiments, this embodiment further specifies that: the laser 200, the dynamic beam shaping module 100, the scanning galvanometer 300, and the field mirror 400 are sequentially connected to form a shaping optical path system. The fixed sequential connection structure makes the optical path layout clear, facilitates the calibration of coaxiality during installation, reduces the difficulty of optical path tracing during subsequent maintenance, and improves the maintainability and optical path stability of the system.

[0101] In addition to the features of the above embodiments, this embodiment further specifies that: each optical component in the shaping optical path system can optionally be fitted with an adjustable optical adjustment frame to facilitate adjustment of the coaxiality of the optical path. Each optical component in the shaping optical path system can be optionally equipped with an adjustable optical adjustment frame, which allows for fine position adjustment of the components in the X / Y / Z axes or rotational directions. This facilitates calibration of the coaxiality of each component during installation or maintenance, avoiding optical path offset caused by component installation deviations. The option of adjusting the frame satisfies both high-precision coaxiality requirements and low-precision or cost-sensitive scenarios, improving the flexibility of system design.

[0102] In addition to the features of the above embodiments, this embodiment further specifies that: each optical component in the shaping optical path system may optionally be equipped with a three-axis to six-axis optical adjustment frame or a universal adjustment frame, depending on the usage requirements of the optical elements, to facilitate the adjustment of the coaxiality of the optical path; preferably, all optical adjustment frames can be locked to improve shock resistance and vibration damping. Three-axis to six-axis adjustment frames or universal adjustment frames are provided according to the usage requirements of the optical elements. Three-axis frames are suitable for simple position adjustments, while six-axis frames or universal frames are suitable for high-precision coaxiality calibration, ensuring that different precision requirements can be met; the locking function of the optical adjustment frames can fix the component position after adjustment, preventing component displacement due to vibration or slight impact during equipment operation, ensuring long-term stability of the optical path coaxiality, and improving the system's anti-interference capability and the consistency of forming quality.

[0103] In addition to the features of the above embodiments, this embodiment further specifies that: the numerical aperture of the scanning galvanometer 300 and the field lens 400 is 1.5-2.5 times the maximum incident beam diameter of the independent diffraction functional region 101, and the spot size incident on the independent diffraction functional region 101 is ≤80% of the minimum size of the functional region. Setting the numerical aperture of the scanning galvanometer 300 and the field lens 400 to 1.5-2.5 times the maximum incident beam diameter of the independent diffraction functional region 101 ensures that the beam can completely enter the effective optical area of ​​the galvanometer and the field lens, avoiding beam edge cutting due to insufficient numerical aperture, resulting in energy loss or spot distortion; the incident spot size is ≤80% of the minimum size of the functional region, ensuring that the spot falls completely within the independent diffraction functional region 101 and does not exceed the edge of the functional region, avoiding deviation in the shaping effect caused by the spot edge incident on non-functional regions, and ensuring the parameter stability and quality of the shaped beam.

[0104] like Figure 1 and Figure 6 As shown in (a), in addition to the features of the above embodiments, this embodiment further specifies that: the shaping optical path system and the powder bed forming cavity 600 are integrally packaged; the laser powder bed melting shaping optical path system also includes a mounting assembly 700, which includes a galvanometer mounting adapter 71, a protective mirror mounting adapter 72, and a first protective mirror 73. One end of the galvanometer mounting adapter 71 is connected to the scanning galvanometer 300, and the other end of the galvanometer mounting adapter 71 is connected to the powder bed forming cavity 600. The bottom of the scanning galvanometer 300 is provided with a threaded hole. The galvanometer mounting adapter 71 is used to fix the shaping optical path system to the powder bed forming cavity 600 via a threaded connection. The height of the galvanometer mounting adapter 71 at the top of the powder bed forming cavity 600 is determined by the relationship between the working distance of the field lens 400 and the height of the powder bed forming cavity 600. A through hole needs to be opened at the top of the powder bed forming cavity 600, and the size of the through hole is generally determined by the outer dimensions of the field lens 400. The protective lens mounting adapter 72 is fixed to the top of the powder bed forming cavity 600 by threads. The first protective lens 73 is set on the protective lens mounting adapter 72. The first protective lens 73 is set opposite to the light outlet of the field lens 400. The first protective lens 73 is used to protect the lens of the field lens 400 from splashes, fumes and other contaminants during the metal melting process in the forming process.

[0105] The shaping optical path system and the powder bed forming cavity 600 are integrated into a single package. The optical path system is mounted on the top of the cavity via a galvanometer mounting adapter 71, resulting in a compact structure that reduces the system's footprint. The height of the galvanometer mounting adapter 71 is determined by the working distance of the field lens 400 and the cavity height, ensuring that the field lens 400 can accurately focus on the surface of the forming cylinder. The through-hole at the top of the powder bed forming cavity 600 is designed according to the external dimensions of the field lens 400, preventing excessively large through-holes from causing dust ingress or excessively small through-holes from obstructing beam transmission. The first protective mirror 73 is located below the light outlet of the field lens 400, effectively blocking splashes and fumes during metal melting, preventing lens contamination or scratches, and extending the lifespan of the field lens 400. The protective mirror can also be replaced individually, reducing maintenance costs. The integrated package combined with the protective mirror design enhances the system's structural stability and maintenance economy.

[0106] like Figure 1 and Figure 6 As shown in (b), in addition to the features of the above embodiments, this embodiment further specifies that: the shaping optical path system and the powder bed forming cavity 600 are separately packaged. The laser powder bed melting shaping optical path system also includes a motion device 800. The motion device 800 includes a lifting device 81, a carrying platform 82, and a second protective mirror 83. The carrying platform 82 has a suitable through hole. The shaping optical path system is fixedly installed on the carrying platform 82 by threads. The carrying platform 82 is set on the lifting device 81. The second protective mirror 83 is located at the top of the powder bed forming cavity 600. The second protective mirror 83 is arranged opposite to the light outlet of the field lens 400. The second protective mirror 83 is used for the propagation of the laser beam and to ensure the sealing of the powder bed forming cavity 600.

[0107] The shaping optical path system and the powder bed forming cavity 600 are separately packaged. The optical path system is installed on the carrier platform 82, which is mounted on the lifting device 81. The height of the optical path system can be adjusted by lifting to adapt to powder bed forming cavities 600 of different heights or to adjust the focusing position of the field lens 400, thereby improving the system's adaptability to cavities of different specifications. The second protective mirror 83 is located at the top of the cavity, which not only ensures the normal transmission of the laser beam but also seals the powder bed forming cavity 600, ensuring the stability of the forming environment. The separate packaging facilitates the individual maintenance of the optical path system or the forming cavity. The design of the lifting device 81 and the protective mirror further enhances the system's flexibility and the reliability of the forming environment.

[0108] In addition to the features of the above embodiments, this embodiment further specifies that: the coaxiality between each optical component of the laser powder bed melting and shaping optical path system is ensured by a strategy of installing and adjusting each component individually; the adjustment process of optical path coaxiality utilizes a spot quality analysis instrument to adjust the coaxiality between optical components by evaluating the shape accuracy and energy distribution of the target spot. The strategy of installing and adjusting each optical component individually avoids the problem of difficulty in locating the source of coaxiality deviation after installing all components at once. Adjustments can be made promptly after installing each component to ensure the coaxiality between the preceding and following components, gradually accumulating to achieve high coaxiality of the entire optical path; the adjustment process utilizes a spot quality analysis instrument to determine whether the coaxiality meets the standard by observing the shape accuracy and energy distribution of the target spot. This is more accurate than traditional visual adjustment, allows for quantitative evaluation of the coaxiality effect, avoids subjective errors, ensures that the optical path coaxiality meets the forming requirements after adjustment, ensures that the shaping beam can be accurately focused on the target area, and improves the quality of metal powder melting and forming.

[0109] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0110] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A dynamic beam shaping module, characterized in that, The dynamic beam shaping module includes: A diffractive optical element (1) includes a light-transmitting substrate (11). The surface of the light-transmitting substrate (11) has at least two independent diffractive functional regions (101) that do not overlap. Different independent diffractive functional regions (101) are provided with different micro-nano relief structures. The micro-nano relief structures are used to adjust the wavefront phase and amplitude of the laser beam to reconstruct the spatial energy distribution characteristics of the laser beam. Different independent diffractive functional regions (101) are used to shape the laser beam with a first shape and a first energy distribution characteristic into a laser beam with a different shape and / or a different energy distribution characteristic. Optical path adjustment mechanism (2), wherein the optical path adjustment mechanism (2) adjusts different independent diffraction functional regions (101) to sequentially align with the laser beam in the first shape and the first energy distribution characteristics; A beam expander (3) is used to dynamically adjust the incident diameter and divergence angle of the laser beam incident on the surface of the diffractive optical element (1).

2. The dynamic beam shaping module according to claim 1, characterized in that, The etching depth of the micro / nano relief structure is designed based on a reverse iterative algorithm, which is solved according to the phase and amplitude distribution of the input beam and the target output beam. The first shape of the input beam includes a circle, rectangle, square, ellipse and straight line, and the first energy distribution characteristics of the input beam include Gaussian beam, uniform beam and point ring beam. The type of the target output beam includes Gaussian beam, uniform beam, vortex beam, Bessel beam, ring beam and point ring beam.

3. The dynamic beam shaping module according to claim 1, characterized in that... The design parameters of the diffractive optical element (1) include at least one of the following design parameters: The shape design parameters of the independent diffraction functional area (101) are set to fan-shaped, circular, fan-ring, or rectangular and not square or square. When the shape of the independent diffraction functional area (101) is set to fan-shaped, circular, or fan-ring, the optical path adjustment mechanism (2) drives the diffraction optical element (1) to rotate. When the independent diffraction functional area (101) is set to rectangular and not square, square, or circular, the optical path adjustment mechanism (2) drives the diffraction optical element (1) to translate linearly. The area design parameters of the independent diffraction functional region (101) are set to have equal or unequal areas for different independent diffraction functional regions (101). When different independent diffraction functional regions (101) have equal areas, it is used to ensure consistent energy utilization of different beam modes. When different independent diffraction functional regions (101) have unequal areas, it is used for scenarios where a larger modulation area is required in a specific mode. The partition position relationship design parameters of the independent diffraction functional area (101) are set to be discrete or continuous according to the switching requirements of the target beam mode. When the partition position relationship of the independent diffraction functional area (101) is set to be discrete, it is suitable for instantaneous switching of beam mode. When the partition position relationship of the independent diffraction functional area (101) is set to be continuous, it is suitable for gradual transition of beam mode. The design parameters for the partitioning arrangement rules of all the independent diffraction functional regions (101) are set to concentric ring distribution, fan-shaped array distribution or linear array.

4. The dynamic beam shaping module according to claim 1, characterized in that... The motion trajectory of the diffractive optical element (1) is linear linear motion, rotational motion, or a combination of linear and rotational motion. The optical path adjustment mechanism (2) includes a stepper motor (21), a sensor (22), and an electric component. The stepper motor (21) drives the electric component, and the sensor (22) is used to detect the position or angle of the electric component.

5. The dynamic beam shaping module according to claim 4, characterized in that... The connection between the diffractive optical element (1) and the optical path adjustment mechanism (2) is an integral package or a split package; the diffractive optical element (1) adopts a circular substrate, a rectangular substrate or a hollow ring substrate; the electric component is an electric rotation component (23) or an electric displacement component (24).

6. The dynamic beam shaping module according to any one of claims 1 to 5, characterized in that... The light-transmitting substrate (11) includes at least one of the following: The material of the light-transmitting substrate (11) is one of fused silica, sapphire, ZnSe and plastic; The thickness of the light-transmitting substrate (11) is 1mm-10mm; The light-transmitting substrate (11) has a transmission wavelength of 193nm-1080nm; The surface of the light-transmitting substrate (11) is provided with a specified wavelength antireflection film to ensure that the transmittance of the specified wavelength laser beam is ≥99.8%. The laser damage threshold of the transparent substrate (11) should meet the requirements of 500W-5000W lasers.

7. A laser powder bed melting and shaping optical path system, characterized in that, include: The dynamic beam shaping module (100) according to any one of claims 1 to 6; A laser (200) is used to emit a collimated beam to the dynamic beam shaping module (100); Scanning galvanometer (300); A field lens (400) is connected to the scanning galvanometer (300) via a junction ring (500); A powder bed forming cavity (600) is arranged opposite to the light outlet of the field lens (400). The light beam emitted by the laser (200) passes sequentially through the beam expander (3), the diffractive optical element (1) and the scanning galvanometer (300), and is finally focused by the field lens (400) onto the surface of the forming cylinder inside the powder bed forming cavity (600).

8. The laser powder bed melting and shaping optical path system according to claim 7, characterized in that, The diffractive optical element (1), the optical path adjustment mechanism (2), and the beam expander (3) are integrated and packaged in a closed housing. The dynamic beam shaping module (100) is usually packaged using an optical housing. The surface of the optical housing is provided with an optical window and a standard flange interface. The optical window is used to connect an external coaxial monitoring system to monitor the changes in the characteristic state of the shaping laser beam in real time during spatial propagation. The standard flange interface is used to detachably install the dynamic beam shaping module (100) to the laser powder bed melting shaping optical path system.

9. The laser powder bed melting and shaping optical path system according to claim 7, characterized in that, The laser (200), the dynamic beam shaping module (100), the scanning galvanometer (300), and the field mirror (400) are sequentially connected to form a shaping optical path system.

10. The laser powder bed melting and shaping optical path system according to claim 9, characterized in that, The shaping optical path system and the powder bed forming cavity (600) are integrally packaged. The laser powder bed melting shaping optical path system also includes a mounting assembly (700). The mounting assembly (700) includes a galvanometer mounting adapter (71), a protective mirror mounting adapter (72), and a first protective mirror (73). One end of the galvanometer mounting adapter (71) is connected to the scanning galvanometer (300), and the other end of the galvanometer mounting adapter (71) is connected to the powder bed forming cavity (600). The protective mirror mounting adapter (72) is disposed on the powder bed forming cavity (600), and the first protective mirror (73) is disposed on the protective mirror mounting adapter (72). The first protective mirror (73) is disposed opposite to the light outlet of the field lens (400), and the first protective mirror (73) is located at the top of the powder bed forming cavity (600). Alternatively, the shaping optical path system and the powder bed forming cavity (600) are separately packaged. The laser powder bed melting shaping optical path system also includes a motion device (800). The motion device (800) includes a lifting device (81), a carrying platform (82), and a second protective mirror (83). The shaping optical path system is disposed on the carrying platform (82), which is disposed on the lifting device (81). The second protective mirror (83) is located at the top of the powder bed forming cavity (600) and is disposed opposite to the light outlet of the field lens (400).

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