Simulation method and device for laser processing of nanoparticles

Abstract

The invention discloses a simulation method and a simulation device for laser processing of nano particles, which are applied to the field of laser precision processing, and according to the method, the process of laser processing of nano particles is simulated, and simulation parameters at all first moments can be used as simulation results. Therefore, the interaction mechanism between the nanoparticles and the laser can be monitored with high time resolution, the interaction mechanism between the nanoparticles and the laser does not need to be obtained through an experiment mode, time and labor are saved, and the efficiency is high. And the photoelectric field is influenced by the morphology of the nanoparticles, so that the photoelectric field change caused by the morphology change of the nanoparticles under laser irradiation can be considered based on the photoelectric field in the simulation model at the first moment and the obtained multi-physical field in the simulation model at the second moment, and the calculation result is more suitable for the actual situation.

Description

Technical Field

[0001] This application relates to the field of laser precision machining, and particularly to a simulation method and device for laser machining of nanoparticles. Background Art

[0002] Flexible conductive devices are basic components in flexible electronics applications, and the patterning of liquid metals is the key to the preparation of flexible conductive devices. Ultrasonic treatment of liquid metals to obtain nanoparticles can overcome the surface energy of liquid metals, and these nanoparticles can be liquid metal nanoparticles. Moreover, by using a laser to provide photothermal energy to the nanoparticles, the nanoparticles can be connected to each other to form a conductive path. Since laser machining of nanoparticles is a multi-physical field process involving light, heat, and force, currently, it is usually necessary to study the interaction mechanism between nanoparticles and lasers to obtain optimal experimental parameters, which can include laser parameters and the types of nanoparticles, etc.

[0003] In related technologies, the interaction mechanism between lasers and nanoparticles is usually studied through experiments. During the research process, expensive experimental instruments such as high-speed cameras and electron microscopes are often required, and the experimental parameters need to be frequently changed. This method is time-consuming and laborious, and has low efficiency. Summary of the Invention

[0004] The present invention provides a simulation method and device for laser machining of nanoparticles, which can solve the problem that the method of obtaining the interaction mechanism between lasers and nanoparticles through experiments in related technologies is time-consuming and laborious and has low efficiency. The technical solutions include: On the one hand, a simulation method for laser machining of nanoparticles is provided. The method includes: During the process of simulating laser machining of nanoparticles based on a simulation model, an iterative process is repeatedly executed based on the simulation model until an iteration termination condition is detected. The iterative process includes: Based on the level set physical field in the simulation model at the first moment, the optical and electric fields in the simulation model at the first moment are obtained, and based on the optical and electric fields in the simulation model at the first moment, the multi-physical fields in the simulation model at the second moment are obtained. The multi-physical fields at least include a thermal field, a fluid field, and a level set physical field. The second moment is later than the first moment, and the time interval between the second moment and the first moment is a time step; If the iteration termination condition is not detected, the first moment and the second moment are updated; wherein, the updated first moment is the second moment before the update, and the time interval between the updated second moment and the second moment before the update is a time step; If the iteration termination condition is detected, the simulation parameters at each first moment are used as the simulation results, and the simulation parameters at least include multi-physical fields.

[0005] Optionally, if the morphology of the nanoparticles changes drastically at the first moment, the time step is the first time step; if the morphology of the nanoparticles changes gently at the first moment, the time step is the second time step; wherein, the first time step is smaller than the second time step.

[0006] Optionally, the method further includes: obtaining a plurality of change velocities of the boundary of the nanoparticles at the first moment; if the maximum value of the absolute values of the plurality of change velocities is greater than or equal to the velocity threshold, it is determined that the morphology of the nanoparticles changes drastically; if the maximum value of the absolute values of the plurality of change velocities is less than the velocity threshold, it is determined that the morphology of the nanoparticles changes gently.

[0007] Optionally, the simulation model includes a plurality of grids; after obtaining the multi-physical fields in the simulation model at the second moment based on the optoelectronic field in the simulation model at the first moment, the method further includes: if the maximum value of the level set physical fields of the plurality of grids is less than the level set physical field threshold, it is determined that the iteration termination condition is detected.

[0008] Optionally, obtaining the optoelectronic field in the simulation model at the first moment based on the level set physical field in the simulation model at the first moment includes: obtaining the relative permittivity of the nanoparticles at the first moment based on the level set physical field in the simulation model at the first moment; obtaining the optoelectronic field in the simulation model at the first moment based on the relative permittivity at the first moment and the optoelectronic field calculation model.

[0009] Optionally, obtaining the relative permittivity of the nanoparticles at the first moment based on the level set physical field in the simulation model at the first moment includes: if the level set physical field is less than the preset value, the relative permittivity of the nanoparticles is the first relative permittivity; if the level set physical field is greater than or equal to the preset value, the relative permittivity is the second relative permittivity; The first relative permittivity is different from the second relative permittivity.

[0010] Optionally, the first relative permittivity is the relative permittivity when the nanoparticles are gas, and the second relative permittivity is the relative permittivity when the nanoparticles are non-gas.

[0011] On the other hand, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the simulation method for laser processing of nanoparticles described in the above aspect is implemented.

[0012] In another aspect, a computer device is provided, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the simulation method of laser processing nanoparticles in the above aspect is implemented.

[0013] In yet another aspect, a simulation device for laser processing nanoparticles is provided. The device includes: An iterative process execution module, configured to repeatedly execute an iterative process based on a simulation model during the simulation of laser processing nanoparticles until an iteration termination condition is detected; wherein, the iterative process includes: Based on the level set physical field in the simulation model at the first moment, obtain the optical and electric field in the simulation model at the first moment, and based on the optical and electric field in the simulation model at the first moment, obtain the multi-physical field in the simulation model at the second moment; wherein, the multi-physical field at least includes a thermal field, a fluid field, and a level set physical field, the second moment is later than the first moment, and the time interval between the second moment and the first moment is a time step; If the iteration termination condition is not detected, update the first moment and the second moment; wherein, the updated first moment is the second moment before update, and the time interval between the updated second moment and the second moment before update is a time step; A determination module, configured to, if the iteration termination condition is detected, use the simulation parameters at each first moment as the simulation result, and the simulation parameters at least include the multi-physical field.

[0014] In summary, the embodiments of the present application provide a simulation method and device for laser processing nanoparticles. The method can obtain the optical and electric field in the simulation model at the first moment based on the level set physical field in the simulation model at the first moment, and obtain the multi-physical field in the simulation model at the second moment based on the optical and electric field in the simulation model at the first moment. If the iteration termination condition is detected, the simulation parameters at each first moment can be used as the simulation result. Thereby, while realizing high-time-resolution monitoring of the interaction mechanism between nanoparticles and laser, there is no need to obtain the interaction mechanism between nanoparticles and laser through experiments, which is time-saving, labor-saving, and has high efficiency. And since the optical and electric field is affected by the morphology of the nanoparticles, then based on the optical and electric field in the simulation model at the first moment, the multi-physical field in the simulation model at the second moment obtained can take into account the change in the optical and electric field caused by the morphological change of the nanoparticles under laser irradiation, making the calculation result more in line with the actual situation.

[0015] The additional aspects and advantages of the present invention will be partly given in the following description, partly will become obvious from the following description, or be understood through the practice of the present invention. Description of the Drawings

[0016] Figure 1It is a flowchart of a simulation method for laser processing of nanoparticles provided by an embodiment of the present application; Figure 2 It is a schematic diagram of laser processing of nanoparticles provided by an embodiment of the present application; Figure 3 It is a schematic diagram of a geometric model provided by an embodiment of the present application; Figure 4 It is a mesh schematic diagram of a geometric model provided by an embodiment of the present application; Figure 5 It is a flowchart of an iterative process provided by an embodiment of the present application; Figure 6 It is a schematic diagram of the volume fraction of nanoparticles at 0.2 nanoseconds (ns) provided by an embodiment of the present application; Figure 7 It is a schematic diagram of the temperature distribution of nanoparticles at 0.2 ns provided by an embodiment of the present application; Figure 8 It is a schematic diagram of the recoil pressure on nanoparticles at 0.2 ns provided by an embodiment of the present application; Figure 9 It is a schematic diagram of the volume fraction of nanoparticles at 5 ns provided by an embodiment of the present application; Figure 10 It is a schematic diagram of the temperature distribution of nanoparticles at 5 ns provided by an embodiment of the present application; Figure 11 It is a schematic diagram of the recoil pressure on nanoparticles at 5 ns provided by an embodiment of the present application; Figure 12 It is another schematic diagram of the volume fraction of nanoparticles at 0.2 ns provided by an embodiment of the present application; Figure 13 It is another schematic diagram of the temperature distribution of nanoparticles at 0.2 ns provided by an embodiment of the present application; Figure 14 It is another schematic diagram of the recoil pressure on nanoparticles at 0.2 ns provided by an embodiment of the present application; Figure 15 It is another schematic diagram of the volume fraction of nanoparticles at 5 ns provided by an embodiment of the present application; Figure 16 It is another schematic diagram of the temperature distribution of nanoparticles at 5 ns provided by an embodiment of the present application; Figure 17 It is another schematic diagram of the recoil pressure on nanoparticles at 5 ns provided by an embodiment of the present application; Figure 18 It is a schematic diagram of the structure of a computer device provided by an embodiment of the present application; Figure 19 It is a block diagram of a simulation device for laser processing of nanoparticles provided by an embodiment of the present application. Specific embodiments

[0017] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

[0018] Flexible conductive devices are basic components in flexible electronic applications. Liquid metals such as gallium-based alloys have both excellent flexibility and conductivity and are ideal materials for preparing flexible conductive devices. The patterning of liquid metals is the key to the preparation of flexible conductive devices. However, the extremely high surface energy of liquid metals themselves makes it difficult for them to wet flexible substrates. Ultrasonic treatment of liquid metals to obtain nanoparticles can overcome the surface energy of liquid metals. However, the oxide layer on the surface of each nanoparticle isolates the nanoparticles from each other and cannot form a conductive path. The nanoparticles can include liquid metal nanoparticles, gold nanoparticles, silver nanoparticles, etc.

[0019] Laser direct writing technology uses a high-energy focused light spot to scan nanoparticles, thereby realizing the processing of liquid metals. It has the characteristics of wide applicability to liquid metals, high precision, and good flexibility. Moreover, laser direct writing technology has great advantages in terms of patterning accuracy, process stability, processing and manufacturing efficiency, and scalability of liquid metals. Therefore, laser direct writing technology is usually used to provide photothermal energy to nanoparticles, so that the nanoparticles break due to the mismatch in thermal expansion between them and their oxide layers, and then conductive paths are formed between the nanoparticles.

[0020] Since the laser processing of nanoparticles is a multi-physical field process involving light, heat, and force, it is currently usually necessary to study the interaction mechanism between nanoparticles and lasers to obtain better experimental parameters, which can include laser parameters and the types of nanoparticles, etc.

[0021] In the related art, the interaction mechanism between lasers and nanoparticles can usually be studied in detail through experiments. This method often requires expensive experimental instruments such as high-speed cameras and electron microscopes, and requires frequent changes of experimental parameters. Therefore, studying only through experiments is time-consuming and laborious, and cannot comprehensively study the temperature field during the processing and the morphological change process of liquid metal nanoparticles.

[0022] In addition, the current laser processing simulation method is applicable to simulating the laser processing of large-sized workpieces (millimeter level and above), but not applicable to nanoparticles with nanoscale dimensions. For large-sized workpieces, the heat source generated by laser irradiation can be regarded as a surface heat source on the surface of the workpiece. However, for nanoparticles with nanoscale dimensions, the heat source generated by laser irradiation is distributed throughout the nanoparticle and should be regarded as a volume heat source.

[0023] In addition, the light field distribution formed during the laser irradiation process determines the heat source of the nanoparticles. However, the current simulation method is still unable to calculate the change in the light field distribution during the morphological change of liquid metal nanoparticles. The interaction between the nanoparticles and the light field under laser irradiation (this interaction includes scattering, absorption, surface plasmon oscillation, etc.) will make the light field distribution very sensitive to the morphology of the liquid metal nanoparticles. During the laser processing, the morphology of the liquid metal nanoparticles will continuously change significantly, and the light field distribution is affected by the morphology of the liquid metal nanoparticles, resulting in an obvious change in the heat source distribution with the change of the morphology of the liquid metal nanoparticles. The current simulation method is too rough in simulating the relevant process and will show obvious distortion when calculating the laser processing of nanoparticles.

[0024] Aiming at the deficiencies of the prior art, the embodiment of the present application provides a simulation method for laser processing of nanoparticles based on the level set method and uses the finite element method to complete numerical calculations. In this method, during the process of the computer device repeatedly executing the iterative process based on the simulation model, it can obtain the optical and electric field (which can characterize the light field distribution) in the simulation model at the first moment based on the level set physical field in the simulation model at the first moment, and obtain the multi-physical field in the simulation model at the second moment based on the optical and electric field in the simulation model at the first moment. If the iteration termination condition is not detected, the second moment and the first moment are updated. If the iteration termination condition is detected, the simulation parameters at each first moment can be used as the simulation results, thereby obtaining the thermal field (i.e., temperature distribution), fluid field, and level set physical field (i.e., the morphology of the nanoparticles) at each first moment during the laser processing of nanoparticles. Thus, while realizing the high-time-resolution monitoring of the interaction mechanism between the nanoparticles and the laser, there is no need to obtain the interaction mechanism between the nanoparticles and the laser through experiments. Compared with the related technology, it saves time and effort and has higher efficiency.

[0025] Moreover, since the optical and electric field is affected by the morphology of the nanoparticles, the multi-physical field in the simulation model at the second moment obtained based on the optical and electric field in the simulation model at the first moment can take into account the change in the optical and electric field caused by the morphological change of the nanoparticles under laser irradiation, making the calculation result more in line with the actual situation.

[0026] In addition, if the iteration termination condition is not detected, update the second moment and the first moment. Then, based on the level set physical field in the simulation model at the updated first moment, obtain the optical and electric fields in the simulation model at the updated first moment, that is, use the transient result at the updated first moment to feedback the calculation of the optical and electric fields, triggering a new round of calculation of the optical and electric fields. Subsequently, based on the optical and electric fields in the simulation model at the updated first moment, obtain the multi-physical fields in the simulation model at the updated second moment, and iterate multiple times until the iteration termination condition is detected. In this way, through the loop calculation method, comprehensively capture the dynamic trajectory of the optical and electric fields evolving with the morphology of the nanoparticles, ensuring a high degree of agreement between the simulation results and the actual physical process.

[0027] Figure 1 is a flowchart of a simulation method for laser processing of nanoparticles provided by an embodiment of the present application. This simulation method can be applied to a computer device. As Figure 1 shown, the method includes: Step 101, during the process of simulating laser processing of nanoparticles based on the simulation model, repeatedly execute the iteration process based on the simulation model until the iteration termination condition is detected.

[0028] After constructing the simulation model of laser processing of nanoparticles, the computer device can repeatedly execute the iteration process based on the simulation model until the iteration termination condition is detected. Among them, the iteration process may include the following steps S1 to S3: S1. Based on the level set physical field in the simulation model at the first moment, obtain the optical and electric fields in the simulation model at the first moment.

[0029] The computer device can obtain the optical and electric fields in the simulation model at the first moment based on the level set physical field in the simulation model at the first moment.

[0030] Among them, the optical and electric fields can characterize the light field distribution, and the level set physical field of the nanoparticles can characterize the morphology of the nanoparticles. In the case of first executing the iteration process, the level set physical field in the simulation model at the first moment can be calculated based on the initial optical and electric fields.

[0031] S2. Based on the optical and electric fields in the simulation model at the first moment, obtain the multi-physical fields in the simulation model at the second moment.

[0032] After the computer device obtains the optical and electric fields in the simulation model at the first moment, it can obtain the multi-physical fields in the simulation model at the second moment based on the optical and electric fields in the simulation model at the first moment. Among them, the second moment is later than the first moment, and the time interval between the second moment and the first moment is a time step.

[0033] S3. If the iteration termination condition is not detected, update the second moment and the first moment.

[0034] If the iteration termination condition is not detected, the second moment and the first moment can be updated. Among them, the updated first moment is the second moment before the update, and the time step is the interval between the updated second moment and the second moment before the update.

[0035] Step 102: If the iteration termination condition is detected, use the simulation parameters at each first moment as the simulation result of the analog simulation.

[0036] Among them, the simulation parameters can at least include multiple physical fields.

[0037] In summary, the embodiment of the present application provides a simulation method for laser processing of nanoparticles. In this method, when the computer device repeatedly executes the iteration process based on the simulation model, it can obtain the optical and electric field in the simulation model at the first moment based on the level set physical field in the simulation model at the first moment, and obtain the multiple physical fields in the simulation model at the second moment based on the optical and electric field in the simulation model at the first moment. If the iteration termination condition is not detected, the second moment and the first moment are updated. If the iteration termination condition is detected, the simulation parameters at each first moment can be used as the simulation result, so as to obtain the thermal field (i.e., temperature distribution), fluid field, and level set physical field (i.e., the morphology of nanoparticles) at each first moment during the laser processing of nanoparticles. Thus, while achieving high-time-resolution monitoring of the interaction mechanism between nanoparticles and lasers, there is no need to obtain the interaction mechanism between nanoparticles and lasers through experiments. Compared with the related technology, it saves time and effort and has high efficiency.

[0038] Moreover, since the optical and electric field is affected by the morphology of the nanoparticles, the multiple physical fields in the simulation model at the second moment obtained based on the optical and electric field in the simulation model at the first moment can take into account the change in the optical and electric field caused by the morphological change of the nanoparticles under laser irradiation, making the calculation result more in line with the actual situation.

[0039] In addition, if the iteration termination condition is not detected, the second moment and the first moment are updated. Thus, based on the level set physical field in the updated simulation model at the first moment, the optical and electric field in the updated simulation model at the first moment is obtained, that is, the transient result at the updated first moment is used to feed back the calculation of the optical and electric field, triggering a new round of calculation of the optical and electric field. Then, based on the optical and electric field in the updated simulation model at the first moment, the multiple physical fields in the updated simulation model at the second moment are obtained, and multiple iterations are advanced until the iteration termination condition is detected. Thus, by means of cyclic calculation, the dynamic trajectory of the optical and electric field evolving with the morphology of the nanoparticles is captured in all directions, ensuring a high degree of agreement between the simulation result and the real physical process.

[0040] In some embodiments, before step 101, the computer device may construct a simulation model for laser processing of nanoparticles. For example, the nanoparticles may be liquid metal nanoparticles, gold nanoparticles, silver nanoparticles, or the like.

[0041] Figure 2 FIG. 4 is a schematic diagram of laser processing of nanoparticles provided by an embodiment of the present application. As Figure 2 shown, the nanoparticle 10 is located on the side of the transparent substrate 20 away from the laser 30. The laser 30 is incident from the side of the transparent substrate 20 away from the nanoparticle 10 through the objective lens 40 and is focused at the interface between the transparent substrate 20 and the nanoparticle 10. Among them, the diameter of the nanoparticle 10 may be 150 nanometers (nm), the transparent substrate 20 may be a transparent sapphire substrate, and the pulse width of the laser 30 is in the nanosecond range.

[0042] In the embodiment of the present application, the computer device may construct a simulation model in simulation software. The process of the computer device constructing a simulation model for laser processing of nanoparticles may include the following steps: Step 1031: Construct a geometric model.

[0043] According to the actual situation, the geometric model constructed by the computer device may be a two-dimensional structure model to improve the calculation efficiency and convergence. Referring to Figure 3 , the geometric model may be a rectangle, the length d1 of the geometric model is 10 micrometers (μm), and the width d2 may be 8 μm.

[0044] The geometric model may include a physical domain and a perfectly matched layer domain 50, where the perfectly matched layer domain 50 wraps the physical domain. The physical domain may include the region where the transparent substrate 20 is located and a mesh refinement layer 60, the mesh refinement layer 60 wraps the nanoparticle 10, and the region between the mesh refinement layer 60 and the perfectly matched layer domain 50 is air. The thickness of the perfectly matched layer domain 50 is greater than 1 / 2 of the wavelength of the laser 30.

[0045] Since the surrounding space of the nanoparticles involves multi-field coupling, and there are complex phase changes and fluid motions, the computer device may perform mesh division on the geometric model. Figure 4 FIG. 5 is a schematic diagram obtained by performing mesh division on the geometric model. Optionally, the mesh may be of any shape. For example, the mesh may be a triangular mesh. And, the size of the mesh in the mesh refinement layer 60 is smaller than the size of the mesh in the inner boundary region of the physical domain, and the size of the mesh in the boundary region is smaller than the size of the mesh in the perfectly matched layer domain 50. Among them, the boundary region refers to the region in the physical domain other than the mesh refinement layer 60. Smaller-sized meshes are divided in the mesh refinement layer 60, and coarser meshes are divided in the boundary region and the perfectly matched layer domain to ensure the balance between calculation accuracy and calculation efficiency.

[0046] Step 1032: Construct an optoelectronic field calculation model.

[0047] After constructing the geometric model, the computer device can construct an optoelectronic field calculation model, and the optoelectronic field can characterize the light field distribution. Among them, the optoelectronic field calculation model can satisfy: Formula (1) In Formula (1), represents the gradient, is the relative magnetic permeability, E is the optoelectronic field, is the wave number of the laser, is the relative dielectric constant of the nanoparticle, is the induced current density, is the conductivity, is the vacuum permittivity, is the angular frequency.

[0048] In the embodiments of the present application, the relative magnetic permeability, the wave number of the laser, the induced current density, the conductivity, the vacuum permittivity, and the angular frequency are all constants, and the computer device pre-stores the relative magnetic permeability, the wave number of the laser, the induced current density, the conductivity, the vacuum permittivity, and the angular frequency.

[0049] The computer device can determine the relative dielectric constant according to the level set physical field of the nanoparticle. If the level set physical field is less than the preset value, the relative dielectric constant is the first relative dielectric constant. If the level set physical field is greater than or equal to the preset value, the relative dielectric constant is the second relative dielectric constant.

[0050] Among them, the first relative dielectric constant is different from the second relative dielectric constant. The computer device can pre-store the preset value. Since the level set physical field of the gas region , and the level set physical field of the liquid region and the solid region . Therefore, it can be considered that when the level set physical field is less than 0.5, the nanoparticle is a gas, and when the level set physical field is greater than or equal to 0.5, the nanoparticle is a liquid or a solid. Therefore, the preset value can be 0.5.

[0051] Optionally, the first relative dielectric constant can be the relative dielectric constant when the nanoparticle is a gas, and the second relative dielectric constant can be the relative dielectric constant when the nanoparticle is not a gas. For example, the second relative dielectric constant can be the relative dielectric constant when the nanoparticle is a liquid.

[0052] Taking the preset value of 0.5 as an example, the relative dielectric constant can satisfy: Formula (2) In Formula (2), is the relative permittivity when the nanoparticles are in a gaseous state, is the relative permittivity when the nanoparticles are in a liquid state, is the level set physical field of the nanoparticles.

[0053] Step 1033: Construct a multi-physical field calculation model.

[0054] After constructing the optoelectronic field calculation model, the computer device can construct a multi-physical field calculation model, which can include: a thermal field calculation model, a fluid field calculation model, and a level set physical field calculation model. Among them, the thermal field calculation model can satisfy: Formula (3) is the density, is the specific heat capacity, is the velocity vector of the fluid, i.e., the fluid field, is the temperature, i.e., the thermal field, is the thermal conductivity, is the total heat source, and t is the time.

[0055] This total heat source can satisfy: Formula (4) is the heat source converted from light energy, is the heat loss caused by the vaporization of the nanoparticles. The heat source converted from light energy is a constant, and the computer device pre-stores this heat source converted from light energy .

[0056] Formula (5) is the target value, is the imaginary part of the relative permittivity of the nanoparticles, represents taking the modulus. is a normalized Gaussian function that changes with time, used to simulate the change of the intensity of the laser light source over time. The computer device can obtain the value of.

[0057] Formula (6) Formula (7) is the mass loss rate when the nanoparticles vaporize, is the latent heat of vaporization. The latent heat of vaporization is a constant, and the computer device can pre-store this latent heat of vaporization , is the interface function.

[0058] Formula (8) is the condensation coefficient (i.e., the coefficient for vapor molecules to return to the liquid region and combine with liquid molecules), is the atomic mass of the nanoparticle, is the Boltzmann constant, is the evaporation temperature, is the standard atmospheric pressure.

[0059] Condensation coefficient , the atomic mass of the nanoparticle , the Boltzmann constant , the evaporation temperature and the standard atmospheric pressure are all constants, and the condensation coefficient can be pre-stored in the computer device , the atomic mass of the nanoparticle , the Boltzmann constant , the evaporation temperature and the standard atmospheric pressure .

[0060] Among them, the interface function The function of the function is to limit the gasification at the gas-liquid boundary, which can satisfy: Formula (9) represents taking the modulus.

[0061] Based on the mass conservation equation and considering the mass loss caused by gasification, a fluid field calculation model is set up, and this fluid field calculation model can satisfy: Formula (10) represents the vapor density of the nanoparticle, represents the liquid density of the nanoparticle. The vapor density of the nanoparticle and the liquid density of the nanoparticle are both constants, and the liquid density of the nanoparticle can be pre-stored in the computer device.

[0062] A fluid field calculation model can also be set up based on the momentum conservation equation, and the fluid field calculation model can satisfy: Formula (11) is the density, is the pressure, is the identity matrix, is the dynamic viscosity, is the melting temperature, is the coefficient of thermal expansion, is the gravitational acceleration vector, is the surface tension, is the recoil pressure of the vapor when the nanoparticles are vaporized, The superscript T in is the transpose symbol, characterizes the transpose of .

[0063] The pressure , the identity matrix , the melting temperature , the coefficient of thermal expansion and the gravitational acceleration vector can all be constants. The pressure , the identity matrix , the melting temperature , the coefficient of thermal expansion and the gravitational acceleration vector can be pre-stored in the computer device.

[0064] Equation (12) represents the surface tension coefficient of the nanoparticles, is the surface curvature, is the surface unit vector.

[0065] The surface tension coefficient , the surface curvature and the surface unit vector are all constants. The surface tension coefficient , the surface curvature and the surface unit vector can be pre-stored in the computer device.

[0066] Equation (13) The level set physical field calculation model can satisfy: Equation (14) In the above equation, represents the partial derivative of the level set physical field with respect to time t. The level set physical field at the gas-liquid interface is 0.5, and the level set physical field is between 0 and 1. is the preset boundary layer thickness, is the initial value. The preset boundary layer thickness and the initial value can be pre-stored in the computer device. Optionally, the boundary layer thickness is set to 1 / 15 of the maximum value of the divided grid.

[0067] In the embodiment of the present application, a simulation model can be set in the simulation software, and the target physical parameters can be generated by the simulation software, and the target physical parameters can include thermal conductivity ,density , heat capacity , dynamic viscosity It should be noted that, for each target physical parameter, the target physical parameter at different times may be different, and the target physical parameters of different grids may also be different.

[0068] In an embodiment of the present application, in the process of calculating multiple physical fields, the computer device can determine the thermal field, fluid field and level set physical field by combining the above formulas 3, 10, 11 and 14.

[0069] Step 1034, construct a cyclic calculation process of the photoelectric field and the multi-physical field.

[0070] After constructing the multi-physics field, the computer device can construct a cyclic calculation process of the optical field and the multi-physics field. The cyclic calculation process may include repeatedly executing the iterative process until the iterative termination condition is detected. Figure 5 , the iterative process may include the following steps A1 to A4: A1. Based on the level set physical field in the simulation model at the first moment, the photoelectric field in the simulation model at the first moment is obtained.

[0071] The computer device can obtain the optical and electrical field in the simulation model at the first moment based on the level set physical field in the simulation model at the first moment.

[0072] In an embodiment of the present application, the computer device can obtain the relative dielectric constant of the nanoparticles at the first moment based on the level set physical field at the first moment, and then obtain the photoelectric field in the simulation model at the first moment based on the relative dielectric constant at the first moment and the photoelectric field calculation model.

[0073] Optionally, the computer device may input the optical field calculation parameters and the relative dielectric constant at the first moment into the optical field calculation model to obtain the optical field in the simulation model at the first moment. The optical field calculation parameters may include parameters in the optical field calculation model other than the optical field and the relative dielectric constant.

[0074] In the embodiment of the present application, if the level set physical field at the first moment is less than a preset value, the relative dielectric constant of the nanoparticle at the first moment is the first relative dielectric constant. If the level set physical field at the first moment is greater than or equal to the preset value, the relative dielectric constant of the nanoparticle at the first moment is the second relative dielectric constant.

[0075] Among them, the first relative permittivity is different from the second relative permittivity. The first relative permittivity is the relative permittivity when the nanoparticles are in a gaseous state, and the second relative permittivity is the relative permittivity when the nanoparticles are in a non-gaseous state.

[0076] Since the relative permittivity of the nanoparticles is related to the level set physical field, the influence of the morphology of the nanoparticles on the optoelectronic field can be reflected therefrom.

[0077] In the case of the first execution of the iterative process, the multi-physical fields in the simulation model at the first moment are determined based on the initial optoelectronic field.

[0078] In some embodiments, the initial optoelectronic field can be pre-stored in the computer device, and the initial optoelectronic field is determined based on the initial optoelectronic field calculation parameters.

[0079] In some embodiments, the initial optoelectronic field calculation parameters can be pre-stored in the computer device, and the computer device can input the initial optoelectronic field calculation parameters into the optoelectronic field calculation model to obtain the initial optoelectronic field.

[0080] Among them, the initial optoelectronic field calculation parameters can include the parameters other than the optoelectronic field in the optoelectronic field calculation model (such as the above formulas 1 and 2).

[0081] In some embodiments, the initial relative permittivity in the initial optoelectronic field calculation parameters can be pre-stored in the computer device.

[0082] In some embodiments, the computer device can determine the initial relative permittivity based on the size relationship between the pre-stored initial level set physical field and a preset value. Among them, the initial level set physical field can be pre-stored in the computer device.

[0083] After determining the initial optoelectronic field, the computer device can input the initial optoelectronic field, the initial level set physical field, and the initial multi-physical field calculation parameters into the multi-physical field calculation model to obtain the multi-physical fields in the simulation model at the first moment in the case of the first execution of the iterative process.

[0084] Among them, the initial multi-physical field calculation parameters can include the parameters other than the optoelectronic field, the thermal field, the fluid field, the level set physical field in formula 6, and the level set physical fields in formulas 7, 9 to 14 in formulas 3 to 14. And the level set physical field in formula 6 is the initial level set physical field.

[0085] In the case of non-first execution of the iterative process, the multi-physical fields in the simulation model at the first moment are determined by the previous iterative process.

[0086] A2. Set the time step.

[0087] If the morphology of the nanoparticles changes significantly at the first moment, the time step can be set to the first time step. If the morphology of the nanoparticles changes mildly at the first moment, the time step can be set to the second time step. Among them, the first time step is smaller than the second time step.

[0088] The computer device can obtain multiple change speeds of the boundary of the nanoparticles at the first moment. The change speed refers to the degree of how fast the boundary position of the nanoparticles changes with time. If the maximum value of the absolute values of the multiple change speeds is greater than or equal to the speed threshold , it can be determined that the morphology of the nanoparticles changes significantly. If the maximum value of the absolute values of the multiple change speeds is less than the speed threshold , it can be determined that the morphology of the nanoparticles changes mildly.

[0089] That is to say, in the case of , the time step , in the case of , the time step . This is the first time step, is the second time step. The speed threshold can be pre-stored in the computer device. For example, the speed threshold can be 100 meters per second (m / s).

[0090] The computer device can obtain multiple change speeds of the nanoparticle boundary through simulation software.

[0091] It should be noted that by setting the time step, the controllability and accuracy of the calculation process can be ensured. During the laser processing of nanoparticles, the degree of change in the morphology of the nanoparticles is not constant. In some periods, the morphology changes mildly, and in some periods, the morphology changes significantly. In the case of significant changes in the morphology of the nanoparticles, a shorter first time step is required to make the calculation results more accurate. In the case of mild changes in the morphology of the nanoparticles, a longer second time step is required. Thus, a balance can be achieved between the accuracy and efficiency of the calculation.

[0092] Moreover, the size of the time step determines the degree of fit between the final calculation result and the actual situation. The smaller the time step , the higher the degree of fit. Moreover, the value of the speed threshold needs to be estimated according to specific circumstances. The smaller the speed threshold , the more accurate the calculation result but the lower the calculation efficiency. The larger the speed threshold , the less accurate the calculation result but the higher the calculation efficiency.

[0093] A3. Based on the optical and electric fields in the simulation model at the first moment, obtain the multi-physical fields in the simulation model at the second moment after a time step from the first moment.

[0094] After the computer device obtains the optical and electric fields in the simulation model at the first moment, it can obtain the multi-physical fields in the simulation model at the second moment based on the optical and electric fields in the simulation model at the first moment. Here, the second moment is later than the first moment, and the time interval between the second moment and the first moment is a time step.

[0095] In the embodiments of the present application, the computer device can obtain the multi-physical fields in the simulation model at the second moment after a time step from the first moment based on the optical and electric fields in the simulation model at the first moment.

[0096] The computer device can input the multi-physical field calculation parameters, the optical and electric fields in the simulation model at the first moment, and the level set physical field at the first moment into the multi-physical field calculation model to obtain the multi-physical fields in the simulation model at the second moment.

[0097] Among them, the multi-physical field calculation parameters can include the parameters other than the optical and electric fields, the thermal field, the fluid field, the level set physical field in Formula 6, and the level set physical fields in Formulas 7, 9 to 14 in Formulas 3 to 14, and the level set physical field in Formula 6 is the level set physical field at the first moment.

[0098] A4. If the iteration termination condition is not detected, update the first moment and the second moment.

[0099] If the computer device does not detect the iteration termination condition, it can update the first moment and the second moment and execute step A1 again. Here, the updated first moment is the second moment, and the time interval between the updated second moment and the second moment before the update is a time step. For example, the updated first moment is the second moment.

[0100] Moreover, the computer device can store the optical and electric fields and the multi-physical fields at the first moment, thereby avoiding being overwritten by the data (such as the optical and electric fields and the multi-physical fields) at the first moment of the next iteration.

[0101] In some embodiments, the simulation model is divided into multiple grids. After obtaining the multi-physical fields in the simulation model at the second moment based on the optical and electric fields in the simulation model at the first moment, the computer device can obtain the level set physical field of the grid to obtain the level set physical fields of multiple grids. If the maximum value of the level set physical fields of multiple grids is greater than or equal to the level set physical field threshold, it can be determined that the nanoparticles are not completely vaporized, so it can be determined that the iteration termination condition is not detected. Among them, the level set physical field threshold can be pre-stored in the computer device.

[0102] In some embodiments, when the iteration duration of the iteration process has not reached the termination duration, the computer device may determine that the iteration termination condition has not been detected. The iteration duration may be the time interval between the start time of the first execution of the iteration process and the detection time, where the detection time is the time when the iteration termination condition is detected, and the termination duration may be pre-stored in the computer device.

[0103] In some embodiments, when the computer device detects that the number of iterations has not reached the maximum number of iterations, it may determine that the iteration termination condition has not been detected. The maximum number of iterations may be pre-stored in the computer device.

[0104] When the iteration termination condition is detected, the computer device may stop the loop calculation.

[0105] Step 1035: Set the material physical parameters.

[0106] The material physical parameters may at least include: the optical parameters of the laser, the photoelectric field calculation model, and the physical parameters required for the multi-physics field calculation model. The physical parameters may include: the initial photoelectric field calculation parameters, the initial level set physical field, and the constants in the photoelectric field calculation model and the multi-physics field calculation model.

[0107] The optical parameters may include the laser spot size, the focal plane position, the wave number, etc. Optionally, the paraxial approximation can be selected to simulate the Gaussian light speed.

[0108] In some embodiments, the specific implementation process of step 102 may refer to the iteration process in step 101 above, and the embodiments of the present application will not repeat it here.

[0109] In some embodiments, if the iteration termination condition is detected, the computer device may use the simulation parameters at each first moment as the simulation result of the analog simulation. The simulation parameters may at least include the multi-physics field. Optionally, the simulation parameters may further include the recoil pressure of the vapor when the nanoparticles are vaporized. .

[0110] In some embodiments, if the maximum value of multiple level set physical fields is less than the level set physical field threshold, it may be determined that the nanoparticles have been completely vaporized, and thus it may be determined that the iteration termination condition has been detected.

[0111] In some embodiments, when the iteration duration of the iteration process reaches the termination duration, the computer device may determine that the iteration termination condition has been detected.

[0112] In some embodiments, when the computer device detects that the number of iterations reaches the maximum number of iterations, it determines that the iteration termination condition has been detected.

[0113] For each grid, the computer device can determine the simulation parameters of each grid in the above manner, thereby achieving high-spatial-resolution monitoring during the processing.

[0114] In the simulation method for laser processing of nanoparticles provided in the embodiments of the present application, high-spatial-resolution and high-time-resolution monitoring of the processing is performed, including temperature distribution, phase change, the force on the nanoparticles, and their morphological changes, etc. Based on the simulation results of the present application, in-depth research on laser processing problems at the nanoscale can be carried out, which is conducive to understanding the laser processing mechanism at the nanoscale and provides a theoretical basis for adjusting experimental parameters. In addition, by taking into account the changes in the optical field distribution caused by a series of morphological changes of the nanoparticles under laser irradiation, the calculation results are more in line with the actual situation. On the premise of maintaining high precision, this simulation method can comprehensively and highly faithfully simulate and reproduce the complex process of laser processing of nanoparticles, providing strong support for in-depth exploration of its internal physical mechanism, while pointing out the direction for the optimal selection of experimental parameters and inspiring more innovative application inspirations.

[0115] In summary, the embodiments of the present application provide a method for laser processing of nanoparticles. During the process of the computer device repeatedly executing the iterative process based on the simulation model, it can obtain the optical and electric field in the simulation model at the first moment based on the level set physical field in the simulation model at the first moment, and obtain the multi-physical field in the simulation model at the second moment based on the optical and electric field in the simulation model at the first moment. If the iteration termination condition is not detected, the second moment and the first moment are updated. If the iteration termination condition is detected, the simulation parameters at each first moment can be used as the simulation results, thereby obtaining the thermal field (i.e., temperature distribution), fluid field, and level set physical field (i.e., the morphology of the nanoparticles) at each first moment during the laser processing of nanoparticles. Since high-time-resolution monitoring of the interaction mechanism between the nanoparticles and the laser is achieved without obtaining the interaction mechanism between the nanoparticles and the laser through experiments, compared with the related art, it saves time and effort and has high efficiency.

[0116] In some embodiments, the computer device can establish a simulation model according to step 301. Figure 3 The size of the nanoparticles in is 150 nm. The size of the geometric model can be 10 μm × 8 μm, the grid refinement layer can be rectangular, and the size of the grid refinement layer can be 1 μm × 0.5 μm. The thickness of the perfectly matched layer domain can be 2 μm.

[0117] The grids in the geometric model are all triangular grids. The size of the grids in the perfectly matched layer domain is 0.75 nm - 200 nm, the size of the grids in the grid refinement layer is 0.08 nm - 20 nm, and the size of the grids in the remaining regions is 0.16 nm - 50 nm.

[0118] The termination duration of the loop calculation process is 5 ns, and the first time step , and the second time step .

[0119] In this embodiment, it is set that when the incident laser starts to irradiate, it is the start time of the calculation, that is, the first first moment. The incident laser is a nanosecond laser, the pulse width of the laser is 5 ns, the wavelength of the laser is 1064 nm, the spot radius of the laser is 17 μm, and the energy density of the laser is 20 joules per square centimeter (J / cm 2 ).

[0120] After the calculation based on the simulation model is completed, the computer device can perform visualization processing on the simulation parameters to obtain the changes in the morphology, temperature distribution, and recoil pressure of the nanoparticles with a diameter of 150 nm under the irradiation of the nanosecond laser with an energy density of 20 J / cm 2 . Figures 6 to 11 It is a schematic diagram of the simulation parameters of the nanoparticles.

[0121] The coordinate system in this schematic diagram is established with the target point of the nanoparticles in the geometric model as the origin, and this target point is in contact with the mesh refinement layer 60. This coordinate system includes a horizontal axis and a vertical axis, and the unit of both is μm. The horizontal axis is parallel to the width direction of the geometric model, and the vertical axis is parallel to the length direction of the geometric model.

[0122] Among them, Figure 6 is a schematic diagram of the volume fraction of the nanoparticles at the moment of 0.5 ns, Figure 7 is a schematic diagram of the temperature distribution of the nanoparticles at the moment of 0.5 ns. Figure 8 is a schematic diagram of the recoil pressure received by the nanoparticles at the moment of 0.5 ns.

[0123] Figure 9 is a schematic diagram of the volume fraction of the nanoparticles at the moment of 5 ns, Figure 10 is a schematic diagram of the temperature distribution of the nanoparticles at the moment of 1 ns, Figure 11 is a schematic diagram of the recoil pressure received by the nanoparticles at the moment of 5 ns.

[0124] From Figures 6 to 11 , it can be seen the temperature distribution, morphological changes, and changes in the recoil pressure of the nanoparticles at different moments. Under the action of the laser, the temperature of the nanoparticles rises rapidly, reaches the vaporization temperature, and a violent phase change (liquid to gas) occurs at the position close to the transparent substrate, forming a cavity. Moreover, the nanoparticles deform under the action of the vaporization recoil pressure.

[0125] In some other embodiments, the computer device can establish a simulation model according to step 301, Figure 3The size of the nanoparticles is 100 nm, the size of the geometric model is 10 μm × 8 μm, and the size of the mesh refinement layer is 1 μm × 0.5 μm. The thickness of the perfectly matched layer domain can be 2 μm.

[0126] All the meshes in the geometric model are triangular meshes. The size of the meshes in the perfectly matched layer domain is 0.75 nm - 200 nm, the size of the meshes in the mesh refinement layer is 0.08 nm - 20 nm, and the size of the meshes in the remaining regions is 0.16 nm - 50 nm.

[0127] The termination duration of the iterative calculation process is set to 5 ns, the first time step , the second time step .

[0128] In this embodiment, it is set that when the incident laser starts to irradiate, it is the start time of the calculation, that is, the first moment. The incident laser is a nanosecond laser, the pulse width of the laser is 5 ns, the wavelength of the laser is 1064 nm, the spot radius of the laser is 17 μm, and the energy density of the laser is 5 J / cm 2 .

[0129] After the calculation based on the simulation model is completed, the computer device can perform visualization processing on the simulation parameters to obtain the changes in the morphology, temperature distribution, and recoil pressure of the nanoparticles with a diameter of 100 nm under the irradiation of 5 J / cm 2 nanosecond laser over time.

[0130] Figures 12 to 17 is a schematic diagram of the simulation parameters of the nanoparticles in the geometric model. The coordinate system in this schematic diagram is established with the target point of the nanoparticles in the geometric model as the origin, and this target point is in contact with the mesh refinement layer 60. This coordinate system includes a horizontal axis and a vertical axis, and the unit of both is μm.

[0131] Among them, Figure 12 is a schematic diagram of the volume fraction of the nanoparticles at the moment of 0.5 ns, Figure 13 is a schematic diagram of the temperature distribution of the nanoparticles at the moment of 0.5 ns, Figure 14 is a schematic diagram of the recoil pressure received by the nanoparticles at the moment of 0.5 ns.

[0132] Figure 15 is a schematic diagram of the volume fraction of the nanoparticles at the moment of 5 ns, Figure 16 is a schematic diagram of the temperature distribution of the nanoparticles at the moment of 5 ns, Figure 17 is a schematic diagram of the recoil pressure received by the nanoparticles at the moment of 5 ns.

[0133] From Figures 12 to 17It can be seen the temperature distribution, morphological changes of the nanoparticles at different times, and the changes in the recoil pressure they are subjected to. The nanoparticles vaporize under the action of the laser, and significant morphological changes occur when the recoil pressure generated by the vaporization acts on the surface of the nanoparticles.

[0134] Figures 6 to 17 It shows the simulation effect of laser processing of nanoparticles in the embodiments of the present application, verifying its high spatial resolution and high temporal resolution.

[0135] The embodiments of the present application provide a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the simulation method of laser processing of nanoparticles described in the above embodiments.

[0136] Figure 18 It is a schematic structural diagram of a computer device provided by the embodiments of the present application. As Figure 18 shown, the computer device includes a memory 1801, a processor 1802, and a computer program stored on the memory 1801 and executable on the processor 1802. When the processor 1802 executes the computer program, it implements the simulation method of laser processing of nanoparticles described in the above embodiments.

[0137] Figure 19 It is a block diagram of a simulation device for laser processing of nanoparticles provided by the embodiments of the present application. As Figure 19 shown, the device includes: A construction module 1901, configured to construct a simulation model for laser processing of nanoparticles; An iterative process execution module 1902, configured to repeatedly execute an iterative process based on the simulation model during the simulation of laser processing of nanoparticles based on the simulation model until an iteration termination condition is detected; wherein, the iterative process includes: Based on the level set physical field in the simulation model at the first moment, obtain the optical and electric fields in the simulation model at the first moment, and based on the optical and electric fields in the simulation model at the first moment, obtain the multi-physical fields in the simulation model at the second moment; wherein, the multi-physical fields at least include a thermal field, a fluid field, and a level set physical field, the second moment is later than the first moment, and the time interval between the second moment and the first moment is a time step; If the iteration termination condition is not detected, update the first moment and the second moment; wherein, the updated first moment is the second moment before the update, and the time interval between the updated second moment and the second moment before the update is a time step; A determination module 1903, configured to, if the iteration termination condition is detected, use the simulation parameters at each first moment as the simulation result, and the simulation parameters at least include multi-physical fields.

[0138] Optionally, if the morphology of the nanoparticles changes drastically at the first moment, the time step is the first time step; If the morphology of the nanoparticles changes mildly at the first moment, the time step is the second time step; wherein, the first time step is less than the second time step.

[0139] Optionally, the iteration process execution module 1902 is further configured to: Obtain multiple change velocities of the boundary of the nanoparticles at the first moment; If the maximum value of the absolute values of the multiple change velocities is greater than or equal to the velocity threshold, it is determined that the morphology of the nanoparticles changes drastically; If the maximum value of the absolute values of the multiple change velocities is less than the velocity threshold, it is determined that the morphology of the nanoparticles changes mildly.

[0140] Optionally, the simulation model includes multiple grids; the iteration process execution module 1902 is further configured to: After obtaining the multi-physical fields in the simulation model at the second moment based on the optical and electric fields in the simulation model at the first moment, if the maximum value of the level set physical fields of the multiple grids is less than the level set physical field threshold, it is determined that the iteration termination condition is detected.

[0141] Optionally, the iteration process execution module 1902 is configured to: Obtain the relative permittivity of the nanoparticles at the first moment based on the level set physical field in the simulation model at the first moment; Obtain the optical and electric fields in the simulation model at the first moment based on the relative permittivity at the first moment and the optical and electric field calculation model.

[0142] The iteration process execution module 1902 is configured to: If the level set physical field is less than the preset value, the relative permittivity of the nanoparticles is the first relative permittivity; If the level set physical field is greater than or equal to the preset value, the relative permittivity is the second relative permittivity; The first relative permittivity is different from the second relative permittivity.

[0143] Optionally, the first relative permittivity is the relative permittivity when the nanoparticles are gas, and the second relative permittivity is the relative permittivity when the nanoparticles are non-gas.

[0144] In summary, the embodiment of the present application provides a device for laser processing of nanoparticles. During the process of repeatedly executing the iterative process based on the simulation model, the device can obtain the optical and electric field in the simulation model at the first moment based on the level set physical field in the simulation model at the first moment, and obtain the multi-physical field in the simulation model at the second moment based on the optical and electric field in the simulation model at the first moment. If the iteration termination condition is not detected, the second moment and the first moment are updated. If the iteration termination condition is detected, the simulation parameters at each first moment can be used as the simulation result, thereby obtaining the thermal field (i.e., temperature distribution), fluid field, and level set physical field (i.e., the morphology of nanoparticles) at each first moment during the laser processing of nanoparticles. Since the interaction mechanism between the nanoparticles and the laser is monitored with high time resolution, and there is no need to obtain the interaction mechanism between the nanoparticles and the laser through experiments, compared with the related technologies, it saves time and effort and has high efficiency.

[0145] It should be noted that the logic and / or steps represented in the flowchart or described in other ways herein, for example, can be considered as a definite sequence list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device), or in combination with these instruction execution systems, apparatus, or devices. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection portion having one or more wirings (electronic device), a portable computer diskette (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other media, then editing, interpreting, or otherwise processing it as appropriate, and then storing it in a computer memory.

[0146] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application specific integrated circuits having appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), and the like.

[0147] In the description of this specification, the descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0148] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0149] In addition, the terms "first", "second", etc. used in the embodiments of the present invention are only for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the technical features indicated in this embodiment. Thus, the features defined with the terms "first", "second", etc. in the embodiments of the present invention can explicitly or implicitly indicate that at least one such feature is included in this embodiment. In the description of the present invention, the meaning of the word "plurality" is at least two or more than two, such as two, three, four, etc., unless otherwise specifically defined in the embodiment.

[0150] In the present invention, unless otherwise clearly specified or limited in the embodiments, the terms "installed", "connected", "coupled" and "fixed" etc. appearing in the embodiments shall be understood in a broad sense. For example, the connection can be a fixed connection, a detachable connection, or integrated. Understandably, it can also be a mechanical connection, an electrical connection, etc.; of course, it can also be directly connected, or indirectly connected through an intermediate medium, or it can be the communication inside two elements, or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific implementation situations.

[0151] In the present invention, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0152] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A simulation method for laser processing of nanoparticles, characterized in that The method includes: During the process of simulating laser processing of nanoparticles based on a simulation model, an iterative process is repeatedly executed based on the simulation model until an iteration termination condition is detected; the iterative process includes: Based on the level set physical field in the simulation model at a first moment, the optical and electric field in the simulation model at the first moment is obtained, and based on the optical and electric field in the simulation model at the first moment, a multi-physical field in the simulation model at a second moment is obtained; the multi-physical field at least includes a thermal field, a fluid field, and the level set physical field, the second moment is later than the first moment, and the time interval between the second moment and the first moment is a time step; If the iteration termination condition is not detected, then update the first moment and the second moment; the updated first moment is the second moment before the update, and the time interval between the updated second moment and the second moment before the update is the time step; If the iteration termination condition is detected, then use the simulation parameters at each of the first moments as the simulation result, and the simulation parameters at least include the multi-physical field.

2. The simulation method for laser processing of nanoparticles according to claim 1, wherein: If the morphology of the nanoparticles changes violently at the first moment, then the time step is a first time step; If the morphology of the nanoparticles changes gently at the first moment, then the time step is a second time step; Wherein, the first time step is less than the second time step.

3. The simulation method for laser processing of nanoparticles according to claim 2, characterized in that, The method further includes: Obtain a plurality of change speeds of the boundary of the nanoparticles at the first moment; If the maximum value of the absolute values of the plurality of change speeds is greater than or equal to a speed threshold, then it is determined that the morphology of the nanoparticles changes violently; If the maximum value of the absolute values of the plurality of change speeds is less than the speed threshold, then it is determined that the morphology of the nanoparticles changes gently.

4. The simulation method for laser processing of nanoparticles according to any one of claims 1 to 3, characterized in that The simulation model includes a plurality of grids; after obtaining the multi-physical field in the simulation model at the second moment based on the optical and electric field in the simulation model at the first moment, the method further includes: If the maximum value of the level set physical fields of the plurality of grids is less than a level set physical field threshold, then it is determined that the iteration termination condition is detected.

5. The simulation method for laser processing of nanoparticles according to any one of claims 1 to 3, characterized in that, Obtaining the optical and electric field in the simulation model at the first moment based on the level set physical field in the simulation model at the first moment includes: Based on the level set physical field in the simulation model at the first moment, obtain the relative permittivity of the nanoparticles at the first moment; Based on the relative permittivity at the first moment and the optical and electric field calculation model, obtain the optical and electric field in the simulation model at the first moment.

6. The simulation method for laser processing of nanoparticles according to claim 5, wherein Obtaining the relative permittivity of the nanoparticles at the first moment based on the level set physical field in the simulation model at the first moment includes: If the level set physical field is less than a preset value, then the relative permittivity of the nanoparticles is a first relative permittivity; If the level set physical field is greater than or equal to the preset value, then the relative permittivity is a second relative permittivity; The first relative permittivity is different from the second relative permittivity.

7. The simulation method for laser processing of nanoparticles according to claim 6, characterized in that, The first relative permittivity is the relative permittivity when the nanoparticles are in a gaseous state, and the second relative permittivity is the relative permittivity when the nanoparticles are not in a gaseous state.

8. A computer-readable storage medium, characterized in that, A computer program is stored thereon, and when the computer program is executed by a processor, it implements the simulation method for laser processing of nanoparticles according to any one of claims 1-7.

9. A computer device, characterized in that, It includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, it implements the simulation method for laser processing of nanoparticles according to any one of claims 1-7.

10. A simulation device for laser processing of nanoparticles, characterized in that, The device includes: An iterative process execution module, configured to repeatedly execute an iterative process based on the simulation model during the simulation of laser processing of nanoparticles based on the simulation model until an iteration termination condition is detected; the iterative process includes: Based on the level set physical field in the simulation model at a first moment, obtaining the optical and electric fields in the simulation model at the first moment, and based on the optical and electric fields in the simulation model at the first moment, obtaining the multi-physical fields in the simulation model at a second moment; the multi-physical fields at least include a thermal field, a fluid field, and the level set physical field, the second moment is later than the first moment, and the time interval between the second moment and the first moment is a time step; If the iteration termination condition is not detected, updating the first moment and the second moment; the updated first moment is the second moment before the update, and the time interval between the updated second moment and the second moment before the update is the time step; A determination module, configured to, if the iteration termination condition is detected, use the simulation parameters at each of the first moments as the simulation result, and the simulation parameters at least include the multi-physical fields.

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