External cavity laser lattice anti-vibration bottom plate and preparation method thereof

Abstract

The invention provides an external cavity laser lattice anti-vibration bottom plate and a preparation method thereof, and relates to the technical field of laser bottom plates, and the external cavity laser lattice anti-vibration bottom plate comprises a bottom layer, a core layer and a surface layer which are stacked in sequence; the bottom layer is of a phonon band gap structure; the arrangement structure of the core layer material is a negative Poisson's ratio Buckling structure with a tension effect, the Buckling structure comprises elastic perforated spherical shells arranged periodically, and the Buckling structure realizes the negative Poisson's ratio effect through buckling of the spherical shells and rotation of connecting nodes; and the surface layer is of an Octet-Truss unit cell structure. According to the lattice anti-vibration bottom plate of the external cavity laser, efficient isolation of multi-frequency-band vibration is achieved through a three-layer structure, meanwhile, light weight and structural stability are achieved, and the lattice anti-vibration bottom plate is suitable for anti-vibration supporting of the external cavity laser.

Description

Technical Field

[0001] This application relates to the field of laser base plate technology, and in particular to an anti-vibration base plate for an external cavity laser and its preparation method. Background Technology

[0002] External cavity lasers are widely used in many high-precision fields such as precision measurement, quantum communication, and laser processing.

[0003] However, during the operation of an external cavity laser, external vibrations can cause mechanical displacement of the laser cavity, which in turn causes changes in the cavity length and ultimately results in laser frequency drift. Traditional base plates mostly adopt solid structures or simple honeycomb structures. When the vibration frequency is in the range of 80-500Hz, the vibration transmissibility of traditional base plates is relatively high (e.g., the transmissibility is -6dB at 100Hz), which cannot effectively attenuate vibration energy and seriously affects the stability of laser output. Summary of the Invention

[0004] In view of this, this application proposes a lattice anti-vibration base plate for an external cavity laser and its preparation method.

[0005] In a first aspect, this application provides a lattice-based vibration-damping substrate for an external cavity laser, the lattice-based vibration-damping substrate comprising a bottom layer, a core layer and a surface layer stacked sequentially; The underlying layer is a phonon bandgap structure; The core layer material is arranged in a Bucklicrystal structure with a negative Poisson's ratio and a tensile effect. The Bucklicrystal structure includes periodically arranged elastic perforated spherical shells. The negative Poisson's ratio effect is achieved by buckling of the spherical shells and rotation of the connecting nodes. The surface layer has an Octet-Truss cell structure.

[0006] In one embodiment, the phonon bandgap structure is a Gyroid hole structure.

[0007] In one embodiment, the depth of the Gyroid hole structure is 2.5-5 mm, the hole diameter is 0.3-0.8 mm, and the arrangement interval is 1.0-2.0 mm.

[0008] In one embodiment, the support surface of the Gyroid porous structure has a nano-ripple structure with an amplitude of 50-200 nm and a period of 1-5 μm.

[0009] In one embodiment, the core layer includes an embedded spiral microchannel, the embedded spiral microchannel comprising a plurality of interconnected channel units; In this system, the water flow direction in adjacent flow channel units is opposite, the flow channel unit extends along the laser heat source path, and the hydraulic diameter of the flow channel unit is 250-350μm.

[0010] In one embodiment, the cell edge length of the Bucklicrystal structure is 1.0-2.0 mm, and the cell rod diameter of the Bucklicrystal structure is 0.2-0.5 mm.

[0011] In one embodiment, the Octet-Truss cell structure has a thickness of 1-5 mm, a cell edge length of 0.6-1.2 mm, and a porosity of 10%-30%.

[0012] Secondly, this application also provides a method for fabricating a lattice-based vibration-damping substrate for an external cavity laser, the method comprising: Provide titanium alloy substrate; Based on the design parameters, the titanium alloy substrate is 3D printed to form an initial substrate, which includes an initial bottom layer, an initial core layer and an initial surface layer that are initially formed and stacked in sequence. The initial substrate is post-processed to form an external cavity laser lattice vibration-damping substrate, wherein the external cavity laser lattice vibration-damping substrate comprises a bottom layer, a core layer, and a surface layer stacked sequentially; the bottom layer is a phonon bandgap structure, the core layer is a Bucklicrystal structure with a negative Poisson's ratio exhibiting a tensile effect, the Bucklicrystal structure comprises periodically arranged elastic perforated spherical shells, and the Bucklicrystal structure achieves the negative Poisson's ratio effect through the buckling of the spherical shells and the rotation of the connecting nodes; the surface layer is an Octet-Truss unit cell structure.

[0013] In one embodiment, the post-processing of the initial substrate includes: The initial substrate is subjected to supercritical CO2 infiltration annealing to form a first intermediate substrate; The first intermediate substrate is subjected to hot isostatic pressing to form the lattice vibration-resistant base plate of the external cavity laser.

[0014] In one embodiment, the post-processing of the initial substrate includes: The initial substrate is subjected to supercritical CO2 infiltration annealing to form a first intermediate substrate, the surface of which has a Gyroid porous structure. A nano-wave structure is formed on the surface of each pillar of the Gyroid hole structure on the surface of the first intermediate substrate by using focused ion beam etching technology to form a second intermediate substrate. The second intermediate substrate is subjected to hot isostatic pressing to form the lattice vibration-resistant base plate of the external cavity laser.

[0015] The lattice vibration-damping substrate for an external cavity laser disclosed in this application has the following advantages over related technologies: 1. The external cavity laser lattice vibration-damping base plate of this application includes a bottom layer, a core layer, and a surface layer. The surface layer adopts an Octet-Truss cell structure, whose three-dimensional truss network disperses vibration energy through axial tension and compression of rod units, and uses the geometric stability of tetrahedral substructures to suppress bending deformation, which can initially attenuate high-frequency vibrations and uniformly distribute loads. The core layer is a negative Poisson's ratio Bucklicrystal structure, which generates a lateral contraction effect through the buckling instability of the elastic perforated spherical shell and the rotation of the connecting nodes, forming nonlinear dissipation of vibration energy in the mid-to-low frequency band, and the negative Poisson's ratio characteristic remains effective under large strain, enhancing broadband vibration resistance. The phonon bandgap structure of the bottom layer forms an elastic wave propagation bandgap in a specific frequency band by means of the scattering and interference effect of the periodic elastic medium, blocking the transmission of vibration from the base plate to the laser body. The three-layer structure achieves efficient isolation of multi-frequency vibrations through a hierarchical mechanism of "high-frequency attenuation-mid-frequency dissipation-low-frequency blocking", combined with the synergistic design of material parameters and lattice configuration, while also being lightweight and structurally stable, and is suitable for vibration-damping support of external cavity lasers.

[0016] 2. By forming a nano-wave pattern on the surface of the pillars of the Gyroid porous structure, nanoscale periodic undulations are introduced into the surface of the micron-scale Gyroid skeleton, forming a "micron-nano" dual-periodic composite configuration. When elastic waves are incident, the periodic geometric modulation of the nano-wave pattern not only enhances the Bragg scattering effect but also induces additional energy dissipation through the coupling of surface waves and volume waves, extending the phonon bandgap to higher frequencies and increasing the bandgap width. Simultaneously, the nano-wave pattern increases surface roughness, improves the interfacial bonding between the structure and the damping coating, and further enhances vibrational energy dissipation.

[0017] 3. The core layer includes embedded spiral microchannels, which enable liquid cooling. These embedded spiral microchannels consist of multiple interconnected flow units with opposite flow directions between adjacent units. The flow units extend spirally along the laser heat source path, allowing for precise distribution along the heat source and increasing the contact perimeter between the fluid and the laser heating area, thereby improving heat transfer efficiency. Therefore, using embedded spiral microchannels to dissipate heat from the external cavity laser reduces the thermal deformation coefficient, meeting sub-micron cavity stability requirements. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of the anti-vibration base plate of the external cavity laser lattice in one embodiment of this application; Figure 2 This is an exploded structural diagram of the anti-vibration base plate of the external cavity laser lattice in one embodiment of this application; Figure 3 This is a schematic flowchart illustrating the fabrication method of the anti-vibration substrate of the external cavity laser lattice in one embodiment of this application.

[0020] Explanation of reference numerals in the attached figures: 11-Bottom layer, 111-Gyroid porous structure, 12-Core layer, 121-Embedded spiral microchannel, 13-Surface layer, 131-Support. Detailed Implementation

[0021] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0022] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0024] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0025] As described in the background section, external cavity lasers are widely used in many high-precision fields such as precision measurement, quantum communication, and laser processing.

[0026] However, during the operation of an external cavity laser, external vibrations can cause mechanical displacement of the laser cavity, which in turn causes changes in the cavity length and ultimately results in laser frequency drift. Traditional base plates mostly adopt solid structures or simple honeycomb structures. When the vibration frequency is in the range of 80-500Hz, the vibration transmissibility of traditional base plates is relatively high (e.g., the transmissibility is -6dB at 100Hz), which cannot effectively attenuate vibration energy and seriously affects the stability of laser output.

[0027] Based on this, in some embodiments, such as Figure 1 and Figure 2 As shown, this application provides a lattice-based vibration damping substrate for an external cavity laser, which includes a bottom layer 11, a core layer 12, and a surface layer 13 stacked sequentially.

[0028] The bottom layer, 11, is a phonon bandgap structure. This phonon bandgap structure is designed to achieve vibration transmission attenuation >20dB within the 80-500Hz frequency range. A phonon bandgap structure refers to a structure in a periodically arranged elastic medium (such as composite materials or crystal structures) where the periodic modulation of material parameters (such as density and elastic modulus) prevents phonons (lattice vibration quanta) from propagating within a specific frequency range, forming a "bandgap" region similar to that in electronic band theory. This structure achieves selective control of elastic wave (sound wave) propagation through the artificial design of periodic units.

[0029] The principle of phonon bandgap structures is based on the scattering and interference effects of elastic waves in periodic media. When an elastic wave is incident on a periodic structure, the scattered waves induced by different unit structures will coherently superimpose: within a specific frequency range, the phase difference of the scattered waves leads to destructive interference, preventing the elastic wave from penetrating the structure and forming a bandgap; while at frequencies outside the bandgap, the wave can propagate freely. This process is similar to Bragg scattering, and the bandgap formation conditions can be determined by using dispersion relations (such as plane wave expansion) based on parameters such as the lattice constant of the periodic structure, material parameters (such as density and shear modulus), and the wavelength of the elastic wave. For example, the bandgap width and position of a periodic structure composed of two different materials arranged alternately can be precisely designed by adjusting the material properties and period length. Setting the bottom layer 11 as a phonon bandgap structure can prevent the propagation of vibration waves in the anti-vibration base plate of the external cavity laser, reduce equipment resonance damage, and improve the stability of the external cavity laser.

[0030] The core layer 12 material is arranged in a Bucklicrystal structure with a negative Poisson's ratio and a tensile effect. The Bucklicrystal structure includes periodically arranged elastic perforated spherical shells. The Bucklicrystal structure achieves the negative Poisson's ratio effect through the buckling of the spherical shells and the rotation of the connecting nodes.

[0031] It should be noted that the three-dimensional metamaterial arrangement structure "Bucklicrystal" with negative Poisson's ratio is a novel artificial periodic structure designed based on fullerenes (such as C60) or their derived carbon structures. Its characteristic is that it expands laterally when under tension and contracts laterally when under compression (i.e., the "tensile expansion effect"), which has unique advantages in lightweighting, energy absorption and flexible devices.

[0032] Because the three-dimensional tensile expansion behavior is induced by elastic buckling, this new type of material is named "bucklicrystals". The tensile expansion behavior originates from the elastic buckling instability of the structural units. This controllable instability causes the material to expand laterally under pressure (negative Poisson's ratio effect). Among them, the classic negative Poisson's ratio "bucklicrystal" structure consists of periodically arranged elastic perforated spherical shells, and the negative Poisson's ratio effect is achieved through the buckling of the spherical shells and the rotation of the connecting nodes. Bucklicrystal structures can be divided into two main categories: octahedral symmetry group (Oh) and icosahedral symmetry group (Ih). The octahedral symmetry group can be further divided into 6-hole spherical shells (corresponding to the vertices of the octahedron), 12-hole spherical shells (the midpoints of the edges of the octahedron), and 24-hole spherical shells (the face centers of the octahedron + edge subdivisions); the icosahedral symmetry group can be further divided into 30-hole spherical shells (the combination of icosahedron edges + vertices) and 60-hole shells (icosahedral face subdivisions). For a detailed explanation of the Bucklicrystal structure, please refer to the description in the literature "3D Soft Metamaterials with Negative Poisson's Ratio".

[0033] The Bucklicrystal structure employs a unique vibration modulation mechanism through periodically arranged elastic perforated spherical shells and negative Poisson's ratio characteristics. When a vibration wave is incident, the spherical shell structure undergoes isotropic volume contraction due to mechanical buckling instability. Combined with the coordinated rotation of the connecting nodes (such as the unidirectional rotation of 12 / 24-hole spherical shell nodes and the semi-clockwise / semi-counterclockwise rotation of 6-hole spherical shell nodes), geometric nonlinearity is introduced into the structure, causing the vibration energy to be significantly attenuated through scattering and interference effects. This mechanism is similar to the selective blocking of elastic waves by phonon band gaps, which can prevent vibration waves of specific frequencies from propagating in the structure. Moreover, the negative Poisson's ratio effect remains effective over a large strain range, avoiding the vibration failure problem of traditional materials under small strain. In addition, its modular crystal assembly method allows for precise design of vibration attenuation frequency bands by adjusting the number of spherical shell holes (6 / 12 / 24 holes) and lattice parameters. Experiments and finite element simulations have confirmed that this structure can significantly reduce mechanical resonance damage and has superior vibration stability and energy dissipation capabilities compared to traditional materials. Therefore, the arrangement structure of the core layer 12 material is a negative Poisson's ratio Bucklicrystal structure with a tensile effect, which can effectively improve vibration stability and energy dissipation capacity.

[0034] Surface layer 13 is an Octet-Truss unit cell structure. The Octet-Truss unit cell structure is a three-dimensional spatial truss structure composed of octahedrons and tetrahedrons. Each node connects 12 struts, forming an efficient mechanical transmission path, and has high symmetry and lightweight and high strength mechanical properties.

[0035] When external loads are applied to the Octet-Truss cell structure, the loads are transmitted axially in tension and compression through the bar elements. Triangular stability (the tetrahedral substructure composed of bar elements) suppresses bending deformation, ensuring uniform stress distribution throughout the structure. Due to the spatially staggered arrangement of the bar elements, the lateral and axial deformations exhibit a coupling effect when the structure is compressed or stretched (some configurations exhibit negative Poisson's ratio characteristics). Furthermore, by adjusting the length, cross-sectional dimensions, and material properties of the bar elements, their equivalent elastic modulus, strength, and energy dissipation capacity can be controlled. Because the bar elements of the Octet-Truss cell structure primarily bear axial forces, the material utilization rate is high, with a density only 5% to 20% of that of solid materials, yet it can withstand high loads. Therefore, surface layer 13 is lightweight while capable of withstanding high loads. Moreover, the three-dimensional truss network can disperse vibration energy, dissipating impact energy through bar element buckling or plastic deformation. Therefore, it can be used as a vibration-resistant support with excellent vibration resistance. In addition, by changing lattice parameters (such as porosity and rod diameter), the stiffness and damping characteristics can be customized to adapt to the vibration isolation of external cavity lasers, so that the lattice anti-vibration base plate of external cavity lasers has excellent vibration resistance.

[0036] The aforementioned external cavity laser lattice vibration-damping base plate includes a bottom layer 11, a core layer 12, and a surface layer 13. The surface layer 13 adopts an Octet-Truss cell structure, whose three-dimensional truss network disperses vibration energy through axial tension and compression of rod units. It utilizes the geometric stability of the tetrahedral substructure to suppress bending deformation, which can initially attenuate high-frequency vibrations and uniformly distribute the load. The core layer 12 is a negative Poisson's ratio Bucklicrystal structure. Through the buckling instability of the elastic perforated spherical shell and the rotation of the connecting nodes, a lateral contraction effect is generated, forming vibration energy in the mid-to-low frequency range. The nonlinear dissipation of energy and the continued effectiveness of the negative Poisson's ratio under large strain enhance broadband vibration resistance; the phonon bandgap structure of the bottom layer 11 utilizes the scattering and interference effects of the periodic elastic medium to form an elastic wave propagation bandgap in a specific frequency band, blocking the transmission of vibration from the bottom plate to the laser body; the three-layer structure achieves efficient isolation of multi-frequency vibration through a hierarchical mechanism of "high-frequency attenuation-mid-frequency dissipation-low-frequency blocking", combined with the synergistic design of material parameters and lattice configuration, while also being lightweight and structurally stable, making it suitable for vibration-resistant support of external cavity lasers.

[0037] In some embodiments, the phonon bandgap structure is a Gyroid hole structure 111.

[0038] Among them, Gyroid pore structure 111 is a porous structure based on a three-dimensional periodic minimum surface. Its geometric feature is a continuous interlocking double helical surface network, which belongs to the cubic crystal system (space group I4132). It consists of two sets of symmetrical intersecting helical channels forming a nodeless continuous skeleton. The pores are periodically distributed in three-dimensional space, and it has both structural symmetry and spatial continuity.

[0039] Based on the above characteristics, when an elastic wave is incident, the periodic undulations of the spiral channel wall induce Bragg scattering of the elastic wave. The scattered waves at different positions interfere and cancel each other out due to phase differences, forming a propagation bandgap in a specific frequency band. Simultaneously, the spatial symmetry of the Gyroid perforated structure 111 (such as the I4132 point group) ensures consistent propagation characteristics of the elastic wave in the x, y, and z axes. By adjusting the skeleton thickness, perforation diameter, and material elastic modulus (such as metal, polymer, or composite material), the bandgap position and width can be precisely controlled. Its continuous, node-free curved surface structure, compared to traditional lattice structures, reduces elastic wave reflection loss, achieving a phonon bandgap effect over a wide frequency range. The surface layer 13, employing the Gyroid perforated structure 111, can combine lightweight design with wide-frequency vibration resistance. Furthermore, the Gyroid perforated structure 111 also facilitates heat diffusion; therefore, the surface layer 13, using the Gyroid perforated structure 111, can simultaneously achieve vibration suppression, heat diffusion, and structural strength.

[0040] In some embodiments, the depth of the Gyroid hole structure 111 is 2.5-5 mm, the hole diameter is 0.3-0.8 mm, and the arrangement interval is 1.0-2.0 mm.

[0041] The depth of the Gyroid hole structure 111 can be 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, and 5mm. The hole diameter can be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, and 0.8mm. The arrangement interval can be 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, and 2.0mm. It should be noted that the above depth values, hole diameters, and arrangement intervals are only some examples of this embodiment. The depth of the Gyroid hole structure 111 can be any value between 2-4mm, the hole diameter can be any value between 0.3-0.8mm, and the arrangement interval can be any value between 1.0-2.0mm.

[0042] For example, with a bottom layer of Gyroid hole structure 111 having a thickness of 3mm, a hole diameter of 0.5mm, and an arrangement period of 1.5mm, simulation verification shows that the vibration transfer function attenuation reaches 22dB in the 80-500Hz frequency band, meeting the design requirement of achieving vibration transmission attenuation >20dB in the 80-500Hz frequency range. Therefore, through reasonable parameter settings, the Gyroid hole structure 111 can effectively achieve vibration transmission attenuation in the 80-500Hz frequency range.

[0043] In some embodiments, such as Figure 1 and Figure 2As shown, the surface of the support 131 of the Gyroid porous structure 111 has a nano-wave structure with an amplitude of 50-200 nm and a period of 1-5 μm.

[0044] The amplitude of the nano-ripple structure can be 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm, 180nm, 190nm, and 200nm. The period of the nano-ripple structure can be 1μm, 2μm, 3μm, 4μm, and 5μm. It should be noted that the above amplitude and period are only some examples of this embodiment; the amplitude of the nano-ripple structure can be any value between 50-200nm, and the period of the nano-ripple structure can be any value between 1-5μm. For example, the amplitude can be set to 100nm, and the period can be 2μm.

[0045] It is understandable that by introducing nanoscale periodic undulations on the surface of the micrometer-scale Gyroid framework, forming a "micrometer-nanometer" dual-period composite configuration, when elastic waves are incident, the periodic geometric modulation of the nano-wave textured surface not only enhances the Bragg scattering effect (the nano-period corresponds to the scattering wavelength of the high-frequency elastic wave), but also induces additional energy dissipation through the coupling effect of surface waves and volume waves, thus extending the phonon bandgap to higher frequencies and increasing the bandgap width. Simultaneously, the amplitude modulation of the nano-wave texture can change the phase difference of the surface-scattered waves. By optimizing the matching relationship between amplitude and period, the destructive interference of scattering can be enhanced in specific frequency bands. For example, when the period of the nano-wave texture matches an integer multiple of half the wavelength of the elastic wave, the bandgap suppression effect is significantly improved. Therefore, the nano-wave textured structure on the surface of the support 131 of the Gyroid hole structure 111 can broaden the phonon bandgap frequency range while blocking the mid-to-low frequency vibrations corresponding to the micrometer-scale structure and the high-frequency noise corresponding to the nano-wave texture (such as high-frequency vibrations of electronic devices). Furthermore, the nano-wave texture increases surface roughness, improves the interfacial bonding between the structure and the damping coating, and further enhances vibration energy dissipation.

[0046] In some embodiments, such as Figure 1 and Figure 2 As shown, the core layer 12 includes an embedded spiral microchannel 121, which includes multiple interconnected channel units.

[0047] In this embodiment, the water flow directions in adjacent flow channel units are opposite, and the flow channel units extend along the laser heat source path. The hydraulic diameter of the flow channel unit is 250-350 μm. The hydraulic diameter of the flow channel unit can be 250 μm, 260 μm, 270 μm, 280 μm, 290 μm, 300 μm, 310 μm, 320 μm, 330 μm, 340 μm, and 350 μm. It should be noted that the above hydraulic diameters are only partial examples of this embodiment, and the hydraulic diameter can be any value between 250-350 μm. For example, if the hydraulic diameter is 300 μm, then after connecting external water cooling systems to the inlet and outlet of the flow channel, the expected flow rate is 0.5 L / min.

[0048] In applications, the heat generated when the external cavity laser is working will cause thermal deformation of the base plate. The thermal deformation coefficient of the traditional milled base plate is as high as 3.8μm / K. This thermal deformation will change the cavity structure, causing the frequency drift to exceed 100kHz, which makes it difficult to meet the submicron level cavity stability requirements.

[0049] In this embodiment, it can be understood that the embedded spiral microchannel 121 can achieve liquid cooling. Furthermore, the embedded spiral microchannel 121 is composed of multiple interconnected channel units, with adjacent channel units flowing in opposite directions. The channel units extend spirally along the laser heat source path, thus precisely distributing along the heat source through a spiral extension path, increasing the contact perimeter between the fluid and the laser heating area, thereby improving heat transfer efficiency. Therefore, by using the embedded spiral microchannel 121 to dissipate heat from the external cavity laser, the thermal deformation coefficient can be reduced, meeting the sub-micron level cavity stability requirements.

[0050] For example, when 25°C deionized water is introduced into the microchannel at a flow rate of 0.8 L / min, the heat exchange efficiency reaches 92%, the thermal deformation coefficient is reduced to 0.7 μm / K, and the frequency drift can be controlled within 100 kHz.

[0051] In some embodiments, the cell edge length of the Bucklicrystal structure is 1.0-2.0 mm, and the cell rod diameter of the Bucklicrystal structure is 0.2-0.5 mm.

[0052] In this embodiment, the cell edge length of the Bucklicrystal structure can be 1.0 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, and 2.0 mm, and the cell rod diameter can be 0.2 mm, 0.3 mm, 0.4 mm, and 0.5 mm. It should be noted that the above cell edge length and cell rod diameter are only some examples of this embodiment; the cell edge length of the Bucklicrystal structure can be any value between 1.0 and 2.0 mm, and the cell rod diameter can be any value between 0.2 and 0.5 mm. For example, the cell edge length of the Bucklicrystal structure can be 1.2 mm, and the cell rod diameter can be 0.3 mm. Under these parameters, finite element simulation verification shows that the negative Poisson's ratio of the Bucklicrystal structure is -0.2.

[0053] In this embodiment, by setting the Bucklicrystal structure to the above-mentioned parameters, the core layer 12 can enhance its ability to buffer and absorb vibrations while providing structural stiffness support.

[0054] In some embodiments, the thickness of the Octet-Truss cell structure is 1-5 mm, the cell edge length of the Octet-Truss cell structure is 0.6-1.2 mm, and the porosity of the Octet-Truss cell is 10%-30%.

[0055] The thickness of the Octet-Truss unit structure can be 1 mm, 2 mm, 3 mm, 4 mm, and 5 mm. The cell edge length of the Octet-Truss unit structure can be 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, and 1.2 mm. The porosity of the Octet-Truss unit can be 10%, 15%, 20%, 25%, and 30%. It should be noted that the above thickness, cell edge length, and porosity are only some examples of this embodiment. The thickness of the Octet-Truss unit structure can be any value between 1 and 5 mm, the cell edge length can be any value between 0.6 and 1.2 mm, and the porosity of the Octet-Truss unit can be any value between 10% and 30%. For example, the thickness of the Octet-Truss unit structure can be 2 mm, the edge length of each cell is 0.8 mm, and the porosity can be 15%.

[0056] In this embodiment, by setting the Octet-Truss cell structure to the above parameters, the surface layer 13 can achieve structural lightweighting while enhancing vibration resistance and thermal stability.

[0057] Based on the above embodiments, in one example, the surface layer 13 is designed as a 2mm thick Octet-Truss cell structure, with each cell having a side length of 0.8mm. The porosity is controlled at 15% by the scanning spacing (120μm) and energy density (60J / mm³). This structure can provide uniform impact stiffness in both the transverse and longitudinal directions. The surface of the support column 131 of the Gyroid porous structure 111 has a nano-corrugated structure with an amplitude that can be set to 100nm and a period of 2μm. The nano-corrugated structure can convert mechanical vibration energy into heat energy, which can enhance vibration energy dissipation and improve the vibration resistance of the base plate. The core layer 12 adopts a Bucklicrystal structure array. The cell parameters of the Bucklicrystal structure are set to a side length of 1.2mm and a rod diameter of 0.3mm. Finite element simulation verifies that its negative Poisson's ratio reaches -0.2. When subjected to transverse compression, it will produce a transverse expansion effect, enhancing the structural damping. The embedded microchannel is designed in a spiral shape along the laser heat source path (e.g., within 5mm of the laser installation position), with a hydraulic diameter controlled at 300μm. The inlet and outlet of the channel are connected to an external water cooling system, and the flow rate is set to 0.5L / min. The phonon bandgap is achieved through the bottom layer 11Gyroid hole structure 111, with a hole diameter of 0.5mm and an arrangement period of 1.5mm. COMSOL simulation verification shows that the vibration transfer function attenuation reaches 22dB in the 80-500Hz frequency band.

[0058] Based on the same inventive concept, this application also provides a method for fabricating a lattice-based vibration-damping substrate for an external cavity laser, such as... Figure 3 As shown, the fabrication method of the external cavity laser lattice anti-vibration substrate includes the following steps S301 to S303.

[0059] S301: Provides titanium alloy substrate.

[0060] The titanium alloy substrate can be Ti-6Al-4V. Furthermore, a gradient lattice structure anti-vibration base plate can be fabricated using laser powder bed melting (LPBF) technology.

[0061] S302: Based on design parameters, 3D printing is performed on a titanium alloy substrate to form an initial substrate. The initial substrate includes an initial bottom layer, an initial core layer, and an initial surface layer that are initially formed and stacked in sequence.

[0062] The steps for 3D printing based on titanium alloy substrates can include multifunctional lattice topology design, simulation analysis, and additive manufacturing. Multifunctional lattice topology design can include parameter design for a surface layer, a core layer, and a bottom layer. For example, the surface layer is an Octet-Truss cell structure with a cell size gradient of 0.5-1 mm to enhance vibration resistance and load-bearing capacity; the core layer is a Bucklicrystal structure with a cell edge length of 1 mm, utilizing the negative Poisson's ratio effect to achieve broadband vibration dissipation; the bottom layer is a Gyroid porous structure with a period of 1.5 mm, serving as a phonon bandgap layer to block vibration propagation.

[0063] The simulation analysis includes lattice vibration transfer function simulation and opto-mechanical-thermal coupling simulation. For example, the lattice vibration transfer function simulation involves setting the simulation software parameters to a frequency range of 1-1000Hz, superimposing a damping ratio function, obtaining the maximum damping gain at 120Hz, and plotting the transfer function curve. The opto-mechanical-thermal coupling simulation involves setting the titanium alloy's elastic modulus to 110GPa and Poisson's ratio to 0.3, performing static structural analysis to determine stress concentration regions, coupling solid mechanics, heat conduction, and fluid dynamics modules, setting the microchannel wall heat transfer coefficient to 1500W / (m²·K), establishing a laser cavity model, analyzing the effect of cavity length variation on frequency, and setting a maximum allowable drift of 80kHz.

[0064] Additive manufacturing involves printing using 3D printing equipment. For example, the parameters can be set as follows: laser power and energy density: 150W (50J / mm³) for the surface layer, 200W (65J / mm³) for the core layer, and 180W (60J / mm³) for the bottom layer, to achieve gradient distribution; scanning path: using a third-order Hilbert space-filling curve, scanning speed of 600-800mm / s, and layer thickness of 30μm to improve structural uniformity.

[0065] Taking the bottom layer as an example, a continuous curved porous structure is formed by adjusting the periodic parameter (P=2mm) and amplitude parameter (A=0.8mm) in the generating function. During 3D printing, a layer thickness of 50μm, a laser power of 180W, and a scanning speed of 800mm / s are used to achieve a hole connectivity rate >98%. This structure is designed based on phonon bandgap theory, and analysis shows that a damping peak (damping ratio 0.3) exists at 120Hz, which can effectively attenuate mid-to-high frequency vibrations. The bottom surface of the bottom layer is machined into a plane with a roughness Ra<0.8μm for connection with the laser base.

[0066] S303: Post-processing the initial substrate to form an external cavity laser lattice vibration-damping base plate. The external cavity laser lattice vibration-damping base plate comprises a bottom layer, a core layer, and a surface layer stacked sequentially. The bottom layer is a phonon bandgap structure. The core layer is made of a Bucklicrystal structure with a negative Poisson's ratio exhibiting a tensile effect. The Bucklicrystal structure includes periodically arranged elastic perforated spherical shells. The negative Poisson's ratio effect is achieved through the buckling of the spherical shells and the rotation of the connecting nodes. The surface layer is an Octet-Truss cell structure.

[0067] Understandably, in step S302, after 3D printing the titanium alloy substrate based on the design parameters, the resulting initial substrate already has a formed bottom layer, core layer, and surface layer structure. However, the initial substrate only has a complete structural shape but has not undergone heat treatment, stress relief, or other optimizations, and therefore does not meet the final performance requirements. Thus, it needs to be stabilized through heat treatment, surface treatment, stress relief, and other processes to form a final lattice vibration-damping base plate with stable mechanical properties and target vibration resistance / thermal stability characteristics. The final formed external cavity laser lattice vibration-damping base plate achieves efficient isolation of multi-frequency vibrations while also being lightweight and structurally stable, making it suitable for vibration-damping support of external cavity lasers.

[0068] In some embodiments, the core layer includes an embedded spiral microchannel, which includes a plurality of interconnected channel units; wherein the water flow direction in adjacent channel units is opposite, the channel units extend along the laser heat source path, and the hydraulic diameter of the channel units is 250-350 μm.

[0069] In applications, the core layer can be pre-designed as an embedded spiral microchannel structure with specific parameters. Then, the channel part of the core layer can be set as a cavity, and no powder is filled inside during printing or it is subsequently cleaned, thus obtaining the embedded spiral microchannel.

[0070] In some embodiments, step S303 involves post-processing the initial substrate, including: supercritical CO2 infiltration annealing of the initial substrate to form a first intermediate substrate; and hot isostatic pressing of the first intermediate substrate to form an external cavity laser lattice anti-vibration base plate.

[0071] It is understandable that supercritical CO2 infiltration annealing (temperature 40-60℃, pressure 7.38-10MPa, holding pressure for 3-5h) is used on the initial substrate. Taking advantage of the characteristics of supercritical CO2, which has both liquid solubility and gas diffusion rate, its molecules penetrate into the intergranular gaps of titanium alloy. Through physical adsorption and chemical activation, the grain boundary energy barrier is reduced, forming a nanoscale CO2 adsorption layer, thereby constructing the first intermediate substrate. Supercritical CO2 infiltration annealing, through grain boundary damping regulation, increases the damping coefficient of the substrate by 40%-60%, effectively dissipating the energy of mid-to-high frequency vibrations.

[0072] It is understandable that since the initial substrate only has a complete structural shape and has not undergone heat treatment, stress relief and other optimizations, it cannot meet the requirements for vibration resistance and thermal stability. Therefore, it is first subjected to supercritical CO2 infiltration annealing (temperature 40-60℃, pressure 7.38-10MPa, holding pressure for 3-5h). Taking advantage of the characteristics of supercritical CO2, which has both liquid dissolution ability and gas diffusion rate, its molecules penetrate into the intergranular gaps of titanium alloy. Through physical adsorption and chemical activation, the grain boundary energy barrier is reduced, forming a nanoscale CO2 adsorption layer, which increases the damping coefficient by 40%-60% and eliminates some micropores, thus obtaining the first intermediate substrate.

[0073] Subsequently, the first intermediate substrate undergoes hot isostatic pressing (850-950℃, 100-150MPa, pressure held for 2-4 hours). In a high-temperature, high-pressure inert gas environment, residual porosity is eliminated through atomic diffusion and plastic flow (porosity reduced to below 0.05 vol%), promoting uniform distribution of the β-Ti phase (content increased to over 98%), ultimately forming a mechanically stable lattice-resistant substrate for external cavity lasers. Furthermore, the synergistic effect of these two processes gives the substrate both high damping characteristics and structural stiffness, with flatness error controlled within λ / 15, reduced thermal expansion coefficient fluctuations, and laser cavity length drift ≤50kHz, meeting the precision vibration resistance and thermal stability requirements of high-power external cavity lasers.

[0074] In some other embodiments, step S303 involves post-processing the initial substrate, including: supercritical CO2 infiltration annealing of the initial substrate to form a first intermediate substrate, the surface of which has a Gyroid porous structure; using focused ion beam etching technology to process the surface of each pillar of the Gyroid porous structure on the surface of the first intermediate substrate to form a nano-ripple structure, thus forming a second intermediate substrate; and hot isostatic pressing of the second intermediate substrate to form an external cavity laser lattice anti-vibration base plate.

[0075] It is understandable that the initial substrate is first subjected to supercritical CO2 infiltration annealing (temperature 40-60℃, pressure 7.38-10MPa, holding pressure for 3-5h). The high diffusivity of supercritical CO2 molecules is utilized to penetrate to the grain boundaries of the titanium alloy, thereby reducing the grain boundary energy barrier through physical adsorption, increasing the damping coefficient by 40%-60%, and eliminating some micropores, forming the first intermediate substrate with a Gyroid porous structure on the surface.

[0076] Subsequently, focused ion beam etching technology was used to process nano-wave structures with amplitudes of 50-200 nm and periods of 1-5 μm on the surface of each pillar of the surface Gyroid porous structure. Bragg scattering was enhanced through the "micron-nano" dual periodic effect, which extended the phonon bandgap to the high-frequency band by 200-500 Hz, forming the second intermediate substrate.

[0077] Finally, the second intermediate substrate is subjected to hot isostatic pressing (temperature 850-950℃, pressure 100-150MPa, holding pressure for 2-4h). Under high temperature and high pressure, the residual porosity is eliminated by atomic diffusion (porosity is reduced to below 0.05vol%), promoting the uniform distribution of β-Ti phase (content of more than 98%), and finally forming the lattice anti-vibration substrate of the external cavity laser.

[0078] Compared to the previous embodiment, in this embodiment, a nano-wave structure is formed on the surface of the pillars of the Gyroid porous structure. This introduces nanoscale periodic undulations into the surface of the micron-sized Gyroid skeleton. The periodic geometric modulation of the nano-wave surface not only enhances the Bragg scattering effect but also induces additional energy dissipation through the coupling of surface waves and volume waves, extending the phonon bandgap to higher frequencies and increasing the bandgap width. Simultaneously, the nano-wave structure increases surface roughness, improves the interfacial bonding between the structure and the damping coating, and further enhances vibrational energy dissipation.

[0079] For example, in the process of fabricating nano-ripple structures on the surface of lattice pillars using focused ion beam (FIB) etching technology, the ripple parameters can be controlled by adjusting the ion beam energy (5keV) and scanning speed (10mm / s): the amplitude is set to 100nm (with an error of ±10nm detected by atomic force microscopy (AFM), and the period is 2μm (observed by scanning electron microscopy (SEM)). The etching path is uniformly distributed along the pillar axis, covering the surfaces of all surface and core pillars.

[0080] Based on the above embodiments, in one example, the mass of the lattice substrate obtained after additive manufacturing is 150g. By reducing material usage through topology optimization, the substrate's dimensions are 100mm × 80mm × 10mm, with a total volume of approximately 18cm³. Taking the density of titanium alloy as 4.5g / cm³, the theoretical mass should be 81g. However, considering the lattice porosity (surface layer 15%, core layer 30%, bottom layer 40%), the actual calculated mass is: surface layer volume 20cm³ × (1-15%) × 4.5g / cm³ = 76.5g, core layer volume 30cm³ × (1-30%) × 4.5g / cm³ = 94.5g, bottom layer volume 50cm³ × (1-40%) × 4.5g / cm³ = 135g, for a total mass of approximately 150g. The actual measured mass using an electronic balance (accuracy 0.1g) is 150.3g, with an error of <1% compared to the theoretical value, representing a 64% weight reduction compared to a traditionally milled substrate (420g).

[0081] The lattice substrate obtained after additive manufacturing exhibits a vibration transmissibility of -26 dB at 100 Hz. The vibration transmissibility test was conducted on a vibration table, with the substrate fixed to the table and an accelerometer mounted on top. A sinusoidal vibration of 100 Hz with an amplitude of 1g was input, and the sensor at the output end measured an acceleration of 0.05g. The transmissibility was calculated as 20 × log10(0.05 / 1) = -26 dB. The ambient temperature during testing was 23℃ ± 1℃, and the humidity was 50% ± 5%, with no additional load on the substrate surface. This result represents a 20 dB improvement over the traditional substrate (-6 dB), meeting the design requirement of attenuation > 20 dB in the 80-500 Hz frequency band. The vibration signal was recorded using a spectrum analyzer, verifying the effectiveness of the phonon bandgap design. In summary, the external cavity laser lattice anti-vibration substrate of this application exhibits better vibration resistance and is lighter than traditional milled substrates, making it effectively suitable for vibration-resistant support of external cavity lasers.

[0082] It should be noted that the fabrication method of the external cavity laser lattice anti-vibration substrate provided in the embodiments of this application is based on the same application concept as the external cavity laser lattice anti-vibration substrate provided in the embodiments of this application. Therefore, for the specific structural description of the external cavity laser lattice anti-vibration substrate, please refer to the aforementioned embodiments of the external cavity laser lattice anti-vibration substrate. Repeated descriptions will not be repeated.

[0083] Those skilled in the art will understand that the features described in the various embodiments and / or claims of this application can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in this application. In particular, the features described in the various embodiments and / or claims of this application can be combined and / or combined in various ways without departing from the spirit and teachings of this application. All such combinations and / or combinations fall within the scope of this application. Therefore, the scope of this application should not be limited to the above embodiments, but should be defined not only by the appended claims, but also by their equivalents. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An external cavity laser crystal lattice vibration-isolating base plate, characterized in that, The outer cavity laser lattice anti-vibration bottom plate comprises a bottom layer, a core layer and a surface layer which are sequentially stacked; The bottom layer is a phonon band gap structure; The arrangement structure of the core layer material is a negative Poisson's ratio Bucklicrystal structure with a negative Poisson's ratio effect, the Bucklicrystal structure comprises periodically arranged elastic perforated spherical shells, and the Bucklicrystal structure realizes the negative Poisson's ratio effect through buckling of the spherical shells and rotation of the connecting nodes; The surface layer is an Octet-Truss unit cell structure.

2. The external cavity laser bench of claim 1, wherein, The phonon band gap structure is a Gyroid hole structure.

3. The external cavity laser bench of claim 2, wherein, The depth of the Gyroid hole structure is 2.5-5mm, the hole diameter is 0.3-0.8mm, and the arrangement interval is 1.0-2.0mm.

4. The external cavity laser bench of claim 2, wherein, The strut surface of the Gyroid hole structure has a nano-ridge structure, the amplitude of the nano-ridge structure is 50-200nm, and the period is 1-5μm.

5. The external cavity laser bench of claim 1, wherein, The core layer comprises embedded spiral micro-flow channels, and the embedded spiral micro-flow channels comprise a plurality of connected flow channel units; The flow directions in adjacent flow channel units are opposite, the flow channel units extend along the laser heat source path, and the flow channel units have a hydraulic diameter of 250-350μm.

6. The external cavity laser bench of claim 1, wherein, The unit cell edge length of the Bucklicrystal structure is 1.0-2.0mm, and the unit cell rod diameter of the Bucklicrystal structure is 0.2-0.5mm.

7. The external cavity laser bench of claim 1, wherein, The thickness of the Octet-Truss unit cell structure is 1-5mm, the unit cell edge length of the Octet-Truss unit cell structure is 0.6-1.2mm, and the porosity of the Octet-Truss unit cell is 10%-30%.

8. A method of making an anti-vibration base plate for an external cavity laser, the method comprising: providing a base plate; providing a plurality of posts; and attaching the plurality of posts to the base plate. The preparation method comprises: providing a titanium alloy base material; 3D printing the titanium alloy base material based on design parameters to form an initial base plate, the initial base plate comprising an initially formed and sequentially stacked initial bottom layer, initial core layer and initial surface layer; post-processing the initial base plate to form an outer cavity laser lattice anti-vibration bottom plate, wherein the outer cavity laser lattice anti-vibration bottom plate comprises a bottom layer, a core layer and a surface layer which are sequentially stacked; the bottom layer is a phonon band gap structure, the material of the core layer is a negative Poisson's ratio Bucklicrystal structure with a negative Poisson's ratio effect, the Bucklicrystal structure comprises periodically arranged elastic perforated spherical shells, and the Bucklicrystal structure realizes the negative Poisson's ratio effect through buckling of the spherical shells and rotation of the connecting nodes; and the surface layer is an Octet-Truss unit cell structure.

9. The method of claim 8, wherein the method further comprises: The post-processing of the initial base plate comprises: performing supercritical CO2 infiltration annealing on the initial base plate to form a first intermediate base plate; performing hot isostatic pressing treatment on the first intermediate base plate to form the outer cavity laser lattice anti-vibration bottom plate.

10. The method of claim 8, wherein the method further comprises: The post-processing of the initial base plate comprises: performing supercritical CO2 infiltration annealing on the initial base plate to form a first intermediate base plate, and the surface layer of the first intermediate base plate is a Gyroid hole structure; The Gyroid hole structure of the first intermediate substrate is processed by using a focused ion beam etching technology to form a nano corrugated structure on the surface of each pillar of the Gyroid hole structure, thereby forming a second intermediate substrate; The second intermediate substrate is subjected to a hot isostatic pressing treatment to form the anti-vibration bottom plate of the external cavity laser crystal lattice.

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