A method for preparing high-transmittance diamond microstructures

Abstract

This application belongs to the field of optoelectronic technology and discloses a method for preparing high-transmittance diamond microstructures. The method includes: step S1, using an anhydrous ethanol suspension and an anhydrous ethanol solution of diamond nanopowder to perform ultrasonic treatment and cleaning on a first substrate to obtain a second substrate; step S2, using a laser to perform surface etching on the second substrate to form diamond growth regions and diamond growth inhibition regions as designed to form a third substrate; step S3, using hydrogen, argon and methane gas to grow diamond on the surface of the third substrate based on the diamond growth regions and diamond growth inhibition regions to obtain a high-transmittance diamond microstructure. By using ultrasonic technology and laser, combined with hydrogen, argon and methane gas, and based on the diamond growth regions and diamond growth inhibition regions, a high-transmittance diamond microstructure is prepared, which improves the efficiency of high-transmittance diamond microstructure preparation.

Description

Technical Field

[0001] This application relates to the field of optoelectronic technology, and more specifically, to a method for preparing high-transmittance diamond microstructures. Background Technology

[0002] Diamond possesses exceptional physical and chemical properties, making it widely applicable in industrial, medical, and scientific fields. The fabrication of diamond microstructures involves controlling growth conditions and parameters through various methods and processes to obtain diamond materials with specific microstructures, demonstrating promising application potential in optics, electronics, and thermal engineering. For example, diamond exhibits optical properties such as high refractive index, high transmittance, high dispersion, and low absorption coefficient. Microstructures on the diamond surface can further enhance the performance and function of optical components, achieving anti-reflective or anti-transmittance effects. Furthermore, diamond's high thermal conductivity and low electrical conductivity make it suitable as a heat sink material for high-power electronic devices. Fabricating diamond structures with microchannels facilitates efficient active heat dissipation using liquid or two-phase fluid media.

[0003] However, due to the high hardness and brittleness of diamond, it is difficult to machine. Using lasers to process diamond directly may cause thermal effects, graphitization, and particulate pollution.

[0004] Therefore, in order to solve the technical problem of difficult diamond microstructure processing in existing diamond preparation methods, there is an urgent need for a high-transmittance diamond microstructure preparation method. Summary of the Invention

[0005] The purpose of this application is to provide a method for preparing high-transmittance diamond microstructures. By using ultrasonic technology and laser, combined with hydrogen, argon and methane gases, and based on the diamond growth region and the diamond growth inhibition region, high-transmittance diamond microstructures are prepared. This solves the problem of difficult diamond microstructure processing in existing diamond preparation methods. The use of methane and hydrogen gases, which are environmentally friendly, improves the optical properties of diamond and increases the preparation efficiency of high-transmittance diamond microstructures.

[0006] In a first aspect, this application provides a method for preparing high-transmittance diamond microstructures, comprising the following steps:

[0007] S1, using an anhydrous ethanol suspension and anhydrous ethanol solution of diamond nanopowder, the first substrate is subjected to ultrasonic treatment and ultrasonic cleaning to obtain the second substrate.

[0008] S2, using a laser to perform surface etching on the second substrate, so that the surface of the second substrate forms the diamond growth region and the diamond growth inhibition region as required by the design, to obtain a third substrate with the diamond growth region and the diamond growth inhibition region after etching treatment; the diamond growth inhibition region is arranged in a staggered array.

[0009] S3, using hydrogen, argon and methane gases, diamond is grown on the surface of the third substrate based on the diamond growth region and the diamond growth inhibition region to obtain a high-transmittance diamond microstructure.

[0010] The high-transmittance diamond microstructure preparation method provided in this application can realize the preparation of high-transmittance diamond microstructures. By using ultrasonic technology and laser, combined with hydrogen, argon and methane gases, based on the diamond growth region and the diamond growth inhibition region, high-transmittance diamond microstructures are prepared. This solves the problem of difficult diamond microstructure processing in existing diamond preparation methods. The use of methane and hydrogen gases, which are environmentally friendly, improves the optical properties of diamond and increases the preparation efficiency of high-transmittance diamond microstructures.

[0011] Optionally, step S1 includes:

[0012] A1, the first substrate is placed in an anhydrous ethanol suspension of the diamond nanopowder and subjected to ultrasonic treatment to obtain the ultrasonically treated first substrate.

[0013] A2, using the anhydrous ethanol solution, the first substrate after ultrasonic treatment is ultrasonically cleaned and then dried to obtain the second substrate.

[0014] The method for preparing high-transmittance diamond microstructures provided in this application can achieve the preparation of high-transmittance diamond microstructures. By using an anhydrous ethanol suspension of diamond nanoparticles, diamond nanoparticles can be attached to the surface of the substrate, providing growth points for subsequent diamond preparation and improving the growth rate and quality of diamond.

[0015] Optionally, the diamond nanopowder is diamond powder with a particle size of 20~100nm; the concentration of the diamond nanopowder in the anhydrous ethanol suspension is 5g / L~20g / L; the ultrasonic frequency during the ultrasonic treatment and ultrasonic cleaning processes is 35~60kHz, and the treatment time and cleaning time of the ultrasonic treatment are both 10~20 minutes.

[0016] Optionally, the laser power is 10~1000W; the laser spot diameter is 10~600μm; the laser pulse width is 1fs~500ns; and the laser repetition frequency is 1~10.6 Hz.

[0017] Optionally, the diamond growth region is used to grow diamond; the diamond growth inhibition region is used to inhibit the diamond growth rate; in step S3, the difference in diamond growth rate between the diamond growth region and the diamond growth inhibition region enables the third substrate to grow a high-transmittance diamond microstructure.

[0018] Optionally, step S3 includes:

[0019] B1, the third substrate is placed on the sample stage of the reaction chamber in the microwave plasma chemical vapor deposition system;

[0020] B2, the hydrogen, argon and methane gas are introduced into the reaction chamber, and the gas pressure, microwave power and temperature of the reaction chamber are adjusted so that diamond grows in the diamond growth region on the surface of the third substrate;

[0021] B3. After the preset growth cycle, the argon and methane gas are stopped, the gas pressure is adjusted to atmospheric pressure and the temperature is adjusted to room temperature, the hydrogen flow rate and the microwave power of the reaction chamber are gradually reduced, and after the third substrate returns to room temperature, the high-transmittance diamond microstructure is obtained.

[0022] The method for preparing high-transmittance diamond microstructures provided in this application can prepare high-transmittance diamond microstructures by using hydrogen, argon and methane gases and adjusting appropriate gas pressure and temperature. This method can prepare diamonds without pollution and improves the preparation efficiency of high-transmittance diamond microstructures.

[0023] Optionally, step B2 includes:

[0024] B21, the ignition operation is performed in the reaction chamber;

[0025] B22, using the hydrogen and argon, based on a preset cleaning pressure, a preset cleaning temperature and a preset first microwave power, plasma cleaning is performed on the surface of the third substrate within a preset first cleaning cycle.

[0026] B23, within the preset growth cycle, the argon gas is stopped, the methane gas is introduced, and the gas pressure in the reaction chamber is adjusted to a preset growth gas pressure threshold so that diamond grows in the diamond growth region on the surface of the third substrate.

[0027] Optionally, the hydrogen flow rate is 80-500 sccm; the argon flow rate is 3-10% of the hydrogen flow rate; the preset cleaning gas pressure is 10-100 Torr; the preset cleaning temperature is 750-900℃; the preset first microwave power is 1-10 kW; the preset first cleaning cycle is 15-30 minutes; the preset growth cycle is 6-12 hours; the methane gas flow rate is 3-5% of the hydrogen flow rate; and the preset growth gas pressure threshold is 70-120 Torr.

[0028] Optionally, step B3 includes:

[0029] B31, after a preset growth cycle, the methane gas is stopped and argon gas is introduced. Based on a preset cleaning gas pressure, a preset cleaning temperature and a preset first microwave power, plasma cleaning is performed on the surface of the third substrate within a preset first cleaning cycle.

[0030] B32, stop the argon gas supply, adjust the gas pressure to atmospheric pressure and the temperature to room temperature, gradually reduce the hydrogen gas flow rate and the microwave power of the reaction chamber, and obtain the high-transmittance diamond microstructure after the third substrate returns to room temperature.

[0031] Optionally, after step S3, the following steps are also included:

[0032] If the high-transmittance diamond microstructure fails to meet the design requirements, then the process returns to step S2 or step S3 based on the growth structure of the high-transmittance diamond microstructure.

[0033] Beneficial effects: The high-transmittance diamond microstructure preparation method provided in this application, through ultrasonic technology and laser, combined with hydrogen, argon and methane gases, based on the diamond growth region and the diamond growth inhibition region, prepares high-transmittance diamond microstructures, solving the problem of difficult diamond microstructure processing in existing diamond preparation methods. The use of methane and hydrogen gases, which are environmentally friendly, improves the optical properties of diamond and increases the preparation efficiency of high-transmittance diamond microstructures. Attached Figure Description

[0034] Figure 1 A flowchart illustrating the method for preparing high-transmittance diamond microstructures provided in this application embodiment.

[0035] Figure 2 This is a schematic diagram of the diamond growth region and the diamond growth inhibition region.

[0036] Figure 3 This is a schematic diagram of the microstructure of high-transmittance diamond. Detailed Implementation

[0037] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0038] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0039] Please refer to Figure 1 , Figure 1 This application discloses a method for preparing high-transmittance diamond microstructures, comprising the following steps:

[0040] Step S1: The first substrate is ultrasonically treated and ultrasonically cleaned using an anhydrous ethanol suspension and an anhydrous ethanol solution of diamond nanopowder to obtain the second substrate.

[0041] Step S2: The surface of the second substrate is etched by laser to form the diamond growth region and the diamond growth inhibition region required by the design on the surface of the second substrate, so as to obtain the third substrate with diamond growth region and diamond growth inhibition region after etching treatment; the diamond growth inhibition region is arranged in a staggered array.

[0042] Step S3: Using hydrogen, argon, and methane gases, diamond is grown on the surface of a third substrate based on the diamond growth region and the diamond growth inhibition region to obtain a high-transmittance diamond microstructure.

[0043] This method for preparing high-transmittance diamond microstructures utilizes ultrasonic technology and lasers, combined with hydrogen, argon, and methane gases. Based on the diamond growth region and the diamond growth inhibition region, it prepares high-transmittance diamond microstructures, solving the problem of difficult diamond microstructure processing in existing diamond preparation methods. By using environmentally friendly gases such as methane and hydrogen, it improves the optical properties of diamond and increases the preparation efficiency of high-transmittance diamond microstructures.

[0044] Specifically, in step S1, the first substrate is ultrasonically treated and ultrasonically cleaned using an anhydrous ethanol suspension and an anhydrous ethanol solution of diamond nanoparticles to obtain the second substrate, comprising:

[0045] A1. The first substrate is placed in an anhydrous ethanol suspension of diamond nanopowder and subjected to ultrasonic treatment to obtain the ultrasonically treated first substrate.

[0046] A2. Using anhydrous ethanol solution, the first substrate after ultrasonic treatment is ultrasonically cleaned and then dried to obtain the second substrate.

[0047] In step S1, the first substrate is placed in an anhydrous ethanol suspension of diamond nanoparticles with a particle size of approximately 20-100 nm (diamond nanoparticle concentration of 5 g / L-20 g / L) for ultrasonic treatment. The ultrasonic frequency is 35-60 kHz, and the ultrasonic treatment time can be 10-20 minutes, resulting in the ultrasonically treated first substrate. The first substrate needs to be modified according to the application of the diamond. Generally, it is a silicon wafer. When diamond is used to manufacture materials such as metals, ceramics, glass, and crystals, the first substrate can also be a metal, ceramic, glass, or crystal. If the particle size of the diamond nanoparticles is too large, it will lead to uneven distribution and increase the surface roughness of the substrate. The concentration of diamond nanoparticles is set at 5 g / L-20 g / L to ensure that the anhydrous ethanol suspension of diamond nanoparticles does not have too low a diamond nanoparticle content, which would prevent the diamond nanoparticles from not fully interacting with the substrate and resulting in insufficient substrate preparation capacity. At the same time, it can also avoid the diamond nanoparticles from agglomerating and settling due to too high a concentration, which would reduce the interaction effect between the diamond nanoparticles and the substrate and reduce the substrate preparation effect.

[0048] The first substrate, after ultrasonic treatment, is cleaned with anhydrous ethanol. The number of cleaning cycles can be set according to the actual situation. The ultrasonic frequency is 35~60kHz, and the ultrasonic cleaning time can be 10~20 minutes. After drying, the second substrate is obtained. It is important to note that the ultrasonic frequency should not be too low or too high. If the ultrasonic frequency is too low, the interaction force will be too large, increasing the surface roughness of the substrate. If the ultrasonic frequency is too high, the interaction force will be too low, preventing the diamond nanopowder from fully interacting with the first substrate.

[0049] The purpose of immersing the first substrate in an anhydrous ethanol suspension of diamond nanoparticles for ultrasonic treatment is to utilize the cavitation effect of the liquid under ultrasound. Under the action of ultrasound, cavitation erosion generates microbubbles, which can cavitate the first substrate, allowing diamond nanoparticles to adhere to the surface of the first substrate. This provides growth points for subsequent diamond preparation, improving the growth rate and quality of diamond.

[0050] Specifically, in step S2, the second substrate is placed on a horizontal worktable, and the surface of the second substrate is etched using a pulsed laser to obtain a third substrate with diamond growth regions and diamond growth inhibition regions after etching. The staggered array arrangement of the diamond growth inhibition regions means that the diamond growth inhibition regions are divided into multiple rows, each row including multiple diamond growth inhibition regions arranged at equal intervals along the row direction, with any two adjacent rows of diamond growth inhibition regions staggered in the row direction.

[0051] The pulsed laser has a laser power of 10~1000W, a spot diameter of 10~600μm, a pulse width of 1fs~500ns, and a repetition frequency of 1~10. 6 Hz.

[0052] Specifically, in step S2, a pulsed laser is used to ablate the second substrate according to design requirements, thereby forming a diamond growth inhibition region, while the unablated portion forms a diamond growth region. Ablation of the second substrate destroys the nanodiamonds attached to the surface of the ablated area (diamond growth inhibition region) with the laser, while the unablated area will grow diamonds based on diamond nanoparticles as seeds. The ablated area loses the diamond nanoparticles, thus significantly reducing the diamond growth rate in the inhibition region. In summary, the difference in diamond growth rate between the diamond growth region and the inhibition region allows for the fabrication of diamonds with a honeycomb-like structure using microwave plasma chemical vapor deposition (MSCVD). This structure has a smaller growth thickness in each inhibition region compared to the diamond growth region, causing the growth region to protrude relative to the inhibition region, forming a honeycomb-like structure and improving transmittance. This results in a high-transmittance diamond microstructure. Similarly, other diamond structures can be fabricated based on the difference in diamond growth rate, depending on actual needs.

[0053] like Figure 2 As shown, Figure 2 This diagram illustrates the diamond growth region and the diamond growth inhibition region. The black circle represents the diamond growth inhibition region, while the white area outside the black circle represents the diamond growth region. Φ50μm indicates that the diameter of the diamond growth inhibition region is 50μm.

[0054] Specifically, in step S3, using hydrogen, argon, and methane gases, diamond is grown on the surface of the third substrate based on the diamond growth region and the diamond growth inhibition region to obtain a high-transmittance diamond microstructure, including:

[0055] B1, place the third substrate on the sample stage of the reaction chamber in the microwave plasma chemical vapor deposition system;

[0056] B2, hydrogen, argon and methane gas are introduced into the reaction chamber, and the gas pressure, microwave power and temperature of the reaction chamber are adjusted so that diamond grows in the diamond growth area on the surface of the third substrate.

[0057] B3. After the preset growth cycle, the argon and methane gas supply is stopped, the gas pressure is adjusted to atmospheric pressure and the temperature is adjusted to room temperature, the hydrogen flow rate and the microwave power of the reaction chamber are gradually reduced, and after the third substrate returns to room temperature, a high-transmittance diamond microstructure is obtained.

[0058] In step S3, the third substrate is placed on the sample stage of the reaction chamber in the microwave plasma chemical vapor deposition system. It is necessary to ensure that the surface of the sample stage is uniform and free of large particles and warping, so as to avoid uneven contact between the sample stage surface and the third substrate, which may cause the third substrate to warp or crack during the heating process.

[0059] Specifically, in step S3, hydrogen, argon, and methane gases are introduced into the reaction chamber, and the gas pressure, microwave power, and temperature of the reaction chamber are adjusted to allow diamond to grow in the diamond growth region on the surface of the third substrate, including:

[0060] B21, ignition operation is performed in the reaction chamber;

[0061] B22 utilizes hydrogen and argon gas, based on preset cleaning gas pressure, preset cleaning temperature and preset first microwave power, to perform plasma cleaning on the surface of the third substrate within a preset first cleaning cycle.

[0062] B23, within the preset growth cycle, stop the introduction of argon gas, introduce methane gas, and adjust the gas pressure in the reaction chamber to the preset growth gas pressure threshold so that diamond can grow in the diamond growth area on the surface of the third substrate.

[0063] In step S3, the gas pressure in the reaction chamber is adjusted to 2-6 Torr, and hydrogen gas is introduced into the reaction chamber at a flow rate of 30-120 sccm to initiate a ignition operation. After the ignition operation is completed, the hydrogen flow rate is increased to 80-500 sccm, and argon gas is introduced at a flow rate of 3-10% of the hydrogen flow rate (i.e., 3-10% of 80-500 sccm). The gas pressure in the reaction chamber is adjusted to 10-100 Torr (i.e., the preset cleaning gas pressure), the microwave power in the reaction chamber is adjusted to 1-10 kW (i.e., the preset first microwave power), and the temperature in the reaction chamber is adjusted to 750-900℃ (i.e., the preset cleaning temperature) to perform plasma cleaning on the surface of the third substrate for a cleaning time of 15-30 minutes (i.e., the preset first cleaning cycle). The purity of the hydrogen and argon gas is not less than 7N.

[0064] While maintaining a constant hydrogen flow rate, stop the argon flow and introduce methane gas at a flow rate of 3-5% of the hydrogen flow rate (i.e., 3-5% of 80-500 sccm). Adjust the gas pressure in the reaction chamber to 70-120 Torr (the preset growth pressure threshold). At this point, the surface temperature of the third substrate is 750-950℃, and diamond growth begins on the surface of the third substrate. The growth time is 6-12 hours (the preset growth cycle). The purity of the methane gas should not be less than 6N.

[0065] Specifically, in step B3, after a preset growth cycle, the introduction of argon and methane gas is stopped, the gas pressure is adjusted to atmospheric pressure and the temperature is adjusted to room temperature, the hydrogen flow rate and the microwave power of the reaction chamber are gradually reduced, and after the third substrate returns to room temperature, a high-transmittance diamond microstructure is obtained, including:

[0066] B31, after the preset growth cycle, the methane gas is stopped and argon gas is introduced. Based on the preset cleaning gas pressure, preset cleaning temperature and preset first microwave power, the surface of the third substrate is plasma cleaned within the preset first cleaning cycle.

[0067] B32, stop the argon gas supply, adjust the gas pressure to atmospheric pressure and the temperature to room temperature, gradually reduce the hydrogen gas flow rate and the microwave power of the reaction chamber, and obtain a high-transmittance diamond microstructure after the third substrate returns to room temperature.

[0068] In step S3, after a preset growth cycle (6-12 hours) of diamond growth begins on the surface of the third substrate, argon gas with a flow rate of 3-10% of the hydrogen flow rate (i.e., 3-10% of 80-500 sccm) is introduced, the gas pressure in the reaction chamber is adjusted to 10-100 Torr (i.e., the preset cleaning gas pressure), the microwave power in the reaction chamber is adjusted to 1-10 kW (i.e., the preset first microwave power), and the temperature in the reaction chamber is adjusted to 750-900℃ (i.e., the preset cleaning temperature) to perform plasma cleaning on the surface of the third substrate for a cleaning time of 15-30 minutes (i.e., the preset first cleaning cycle).

[0069] Argon gas supply was stopped, and hydrogen flow rate, pressure, microwave power, and temperature were gradually reduced until the pressure dropped to atmospheric pressure, the temperature to room temperature, and the hydrogen and microwave power to zero. The cooling rate was set to less than 1°C per second to prevent thermal mismatch from causing significant stress on the diamond and third substrate surfaces, which could lead to damage. After the third substrate returned to room temperature, the substrate with the diamond microstructure was removed, resulting in a high-transmittance diamond microstructure, such as... Figure 3 As shown, Figure 3This is a schematic diagram of the high-transmittance diamond microstructure. As can be seen from the figure, diamonds only grow in the diamond growth region and not in the black region where diamond growth is inhibited. Based on the difference in diamond growth between the two regions, the high-transmittance diamond microstructure can be obtained.

[0070] Specifically, after obtaining a high-transmittance diamond microstructure by using hydrogen, argon, and methane gases to grow diamond on the surface of a third substrate, based on the diamond growth region and the diamond growth inhibition region, the process also includes:

[0071] If the high transmittance diamond microstructure does not meet the design requirements, then return to step S2 or step S3 according to the growth structure of the high transmittance diamond microstructure.

[0072] After preparing the high-transmittance diamond microstructure, it needs to be observed under a high-magnification microscope. If the high-transmittance diamond microstructure does not meet the design requirements, the process returns to step S2 or step S3 based on the growth structure of the high-transmittance diamond microstructure. That is, if the diamond in the high-transmittance diamond microstructure has not grown completely in all diamond growth areas, the process returns to step S3, and the growth time is shortened based on the diamond coverage in the diamond growth areas. If the diamond in the high-transmittance diamond microstructure has grown in the diamond growth inhibition area, the process returns to step S2, and the diamond grown in the diamond growth inhibition area is laser-ablated, and the growth time is shortened based on the diamond coverage in the diamond growth area.

[0073] As can be seen from the above, the method for preparing high-transmittance diamond microstructures involves the following steps: Step S1, using anhydrous ethanol suspension and anhydrous ethanol solution of diamond nanopowder to ultrasonically treat and clean the first substrate to obtain a second substrate; Step S2, using laser to etch the surface of the second substrate to form the designed diamond growth region and diamond growth inhibition region, resulting in a third substrate with the etched diamond growth region and diamond growth inhibition region; Step S3, using hydrogen, argon, and methane gas, diamond is grown on the surface of the third substrate based on the diamond growth region and diamond growth inhibition region to obtain a high-transmittance diamond microstructure. Therefore, by combining ultrasonic technology and laser with hydrogen, argon, and methane gas, and based on the diamond growth region and diamond growth inhibition region, a high-transmittance diamond microstructure is prepared, solving the problem of difficult diamond microstructure processing in existing diamond preparation methods. The use of environmentally friendly gases such as methane and hydrogen improves the optical performance of diamond and increases the preparation efficiency of high-transmittance diamond microstructures.

[0074] In this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, without necessarily requiring or implying any such actual relationship or order between these entities or operations.

[0075] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for preparing high-transmittance diamond microstructures, characterized in that, Including the following steps: S1, using an anhydrous ethanol suspension and anhydrous ethanol solution of diamond nanopowder, the first substrate is subjected to ultrasonic treatment and ultrasonic cleaning to obtain the second substrate. S2, using a laser to perform surface etching on the second substrate, so that the surface of the second substrate forms the diamond growth region and the diamond growth inhibition region as required by the design, to obtain a third substrate with the diamond growth region and the diamond growth inhibition region after etching treatment; the diamond growth inhibition region is arranged in a staggered array. S3, using hydrogen, argon and methane gas, diamond is grown on the surface of the third substrate based on the diamond growth region and the diamond growth inhibition region to obtain a high-transmittance diamond microstructure. The laser power is 10~1000W; the laser spot diameter is 10~600μm; the laser pulse width is 1fs~500ns; and the laser repetition frequency is 1~10. 6 Hz; The diamond growth region is used to grow diamond; the diamond growth inhibition region is used to inhibit the diamond growth rate; in step S3, the difference in diamond growth rate between the diamond growth region and the diamond growth inhibition region enables the third substrate to grow a high-transmittance diamond microstructure.

2. The method for preparing high-transmittance diamond microstructures according to claim 1, characterized in that, Step S1 includes: A1, the first substrate is placed in an anhydrous ethanol suspension of the diamond nanopowder and subjected to ultrasonic treatment to obtain the ultrasonically treated first substrate. A2, using the anhydrous ethanol solution, the first substrate after ultrasonic treatment is ultrasonically cleaned and then dried to obtain the second substrate.

3. The method for preparing high-transmittance diamond microstructures according to claim 2, characterized in that, The diamond nanopowder is diamond powder with a particle size of 20~100nm; the concentration of the diamond nanopowder in the anhydrous ethanol suspension is 5g / L~20g / L; the ultrasonic frequency in the ultrasonic treatment and ultrasonic cleaning processes is 35~60kHz, and the treatment time of the ultrasonic treatment and the cleaning time of the ultrasonic cleaning are both 10~20 minutes.

4. The method for preparing high-transmittance diamond microstructures according to claim 1, characterized in that, Step S3 includes: B1, the third substrate is placed on the sample stage of the reaction chamber in the microwave plasma chemical vapor deposition system; B2, the hydrogen, argon and methane gas are introduced into the reaction chamber, and the gas pressure, microwave power and temperature of the reaction chamber are adjusted so that diamond grows in the diamond growth region on the surface of the third substrate; B3. After the preset growth cycle, the argon and methane gas are stopped, the gas pressure is adjusted to atmospheric pressure and the temperature is adjusted to room temperature, the hydrogen flow rate and the microwave power of the reaction chamber are gradually reduced, and after the third substrate returns to room temperature, the high-transmittance diamond microstructure is obtained.

5. The method for preparing high-transmittance diamond microstructures according to claim 4, characterized in that, Step B2 includes: B21, the ignition operation is performed in the reaction chamber; B22, using the hydrogen and argon, based on a preset cleaning pressure, a preset cleaning temperature and a preset first microwave power, plasma cleaning is performed on the surface of the third substrate within a preset first cleaning cycle. B23, within the preset growth cycle, the argon gas is stopped, the methane gas is introduced, and the gas pressure in the reaction chamber is adjusted to a preset growth gas pressure threshold so that diamond grows in the diamond growth region on the surface of the third substrate.

6. The method for preparing high-transmittance diamond microstructures according to claim 5, characterized in that, The hydrogen flow rate is 80-500 sccm; the argon flow rate is 3-10% of the hydrogen flow rate; the preset cleaning gas pressure is 10-100 Torr; the preset cleaning temperature is 750-900℃; the preset first microwave power is 1-10 kW; the preset first cleaning cycle is 15-30 minutes; the preset growth cycle is 6-12 hours; the methane gas flow rate is 3-5% of the hydrogen flow rate; and the preset growth gas pressure threshold is 70-120 Torr.

7. The method for preparing high-transmittance diamond microstructures according to claim 4, characterized in that, Step B3 includes: B31, after a preset growth cycle, the methane gas is stopped and argon gas is introduced. Based on a preset cleaning gas pressure, a preset cleaning temperature and a preset first microwave power, plasma cleaning is performed on the surface of the third substrate within a preset first cleaning cycle. B32, stop the argon gas supply, adjust the gas pressure to atmospheric pressure and the temperature to room temperature, gradually reduce the hydrogen gas flow rate and the microwave power of the reaction chamber, and obtain the high-transmittance diamond microstructure after the third substrate returns to room temperature.

8. The method for preparing high-transmittance diamond microstructures according to claim 1, characterized in that, After step S3, the following is also included: If the high-transmittance diamond microstructure fails to meet the design requirements, then the process returns to step S2 or step S3 based on the growth structure of the high-transmittance diamond microstructure.

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