A crystal preparation device

Abstract

The embodiments of this specification provide a crystal preparation device. The crystal preparation device includes: a cavity for placing raw materials; a laser heating component for heating the raw materials; and a control component for adjusting the heating parameters of the laser heating component in real time during the crystal growth process to adjust the temperature gradient during the crystal growth process.

Description

Technical Field

[0001] This specification relates to the field of crystal preparation technology, and in particular to a crystal preparation device. Background Art

[0002] With the advancement of science and technology, some high-end devices and scientific research requirements have increasingly stringent requirements for crystal quality. During the crystal growth process, factors such as the temperature field and temperature gradient directly affect crystal quality. Therefore, it is necessary to provide an improved crystal preparation device that facilitates real-time and precise control of the temperature field and temperature gradient during crystal growth. Summary of the Invention

[0003] One embodiment of this specification provides a crystal preparation device. The crystal preparation device includes: a chamber for placing a raw material; a laser heating assembly for heating the raw material; and a control assembly for adjusting the heating parameters of the laser heating assembly in real time during the crystal growth process to adjust the temperature gradient during the crystal growth process.

[0004] In some embodiments, the cavity includes a cooling structure including an inlet, an outlet, and a cooling channel.

[0005] In some embodiments, the laser heating assembly includes at least two laser emitting units installed on a furnace cover above the cavity.

[0006] In some embodiments, the at least two laser emitting units are distributed along the circumference of the furnace cover to form at least one annular shape.

[0007] In some embodiments, the difference between the radius of the outermost annular shape and the radius of the cavity is in the range of 50 mm to 500 mm.

[0008] In some embodiments, the radius of the innermost annular shape is in the range of 25 mm - 300 mm.

[0009] In some embodiments, the spacing between adjacent annular shapes is in the range of 5 mm to 200 mm.

[0010] In some embodiments, the heating parameters of the laser heating assembly include at least one of operating power, a shape of the laser beam, or a size of the laser beam.

[0011] In some embodiments, the crystal preparation device further includes a temperature measurement component for measuring temperature information related to the raw material or the cavity, and the control component further adjusts the heating parameters of the laser heating component in real time based on the temperature information.

[0012] In some embodiments, the control component further performs simulation modeling based on the temperature information, and adjusts the heating parameters of the laser heating component in real time based on the simulation results. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] This specification will be further described in the form of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting, and in these embodiments, like numbers represent like structures, wherein:

[0014] Figure 1 It is a schematic structural diagram of an exemplary crystal preparation device according to some embodiments of this specification.

[0015] Figure 2 is a schematic structural diagram of an exemplary cavity according to some embodiments of this specification.

[0016] Figure 3 It is a schematic structural diagram of an exemplary cavity and insulation component shown in some embodiments of this specification.

[0017] Figure 4A is a top view of an exemplary furnace cover according to some embodiments of the present specification.

[0018] Figure 4B is a top view of an exemplary furnace cover according to some other embodiments of the present specification.

[0019] Figure 5 It is a schematic diagram of the installation structure of at least two laser emitting units according to some embodiments of this specification.

[0020] Figure 6 It is a schematic diagram of the temperature field distribution inside the cavity according to some embodiments of this specification.

[0021] Figure 7 This is a schematic diagram of the crystal prepared according to Example 1 of this specification.

[0022] Figures 8A-8B This is a schematic diagram of the crystal prepared according to Example 2 of this specification.

[0023] In the figure, 100 is a crystal preparation device, 110 is a furnace body, 111 is a furnace body, 112 is a furnace cover, 1121 is a first through hole, 1122 is a laser input window, 11221 is a laser input window top cover, 11222 is a laser input window column, 11223 is a connecting piece, 1123 is a cooling passage, 1124 is a passage entrance, 1125 is a passage exit, 1126 is a passage, 113 is a bottom plate, 120 is a pulling component, 121 is a sealing sleeve, 130 is a moving component, 140 is a furnace frame, 1 50 is a moving component, 151 is a moving rod, 152 is a driving component, 200 is a cavity, 210 is a cooling structure, 211 is an inlet, 212 is an outlet, 213 is a cooling channel, 220 is an inner cavity, 230 is an outer cavity, 300 is a heat preservation component, 310 is an upper heat preservation component, 311 is a first gap, 312 is at least two through holes, 320 is a middle heat preservation component, 330 is a lower heat preservation component, 400 is a tray component, 410 is a tray through hole, and 500 is at least two laser emitting units. DETAILED DESCRIPTION

[0024] To more clearly illustrate the technical solutions of the embodiments of this specification, the following briefly describes the drawings required for describing the embodiments. Obviously, the drawings described below are merely examples or embodiments of this specification. Those skilled in the art can apply this specification to other similar scenarios based on these drawings without inventive effort. Unless otherwise apparent from the context or otherwise noted, the same reference numerals in the figures represent the same structure or operation.

[0025] It should be understood that the terms "system," "device," "unit," and / or "module" used herein are a method for distinguishing different components, elements, parts, portions, or assemblies at different levels. However, if other terms can achieve the same purpose, the terms may be replaced by other expressions.

[0026] As used in this specification and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not refer to the singular but also include the plural. Generally speaking, the terms "comprises" and "include" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements.

[0027] Figure 1 1 is a schematic diagram of an exemplary crystal preparation apparatus according to some embodiments of this specification. In some embodiments, the crystal preparation apparatus 100 can be used to prepare crystals such as YAG, LN, LT, LSO, LYSO, BBO, LBO, YVO4, and doped crystals thereof.

[0028] In some embodiments, as Figure 1 As shown, the crystal preparation device 100 may include a furnace body 110, a cavity (not shown in the figure), a heating component (not shown in the figure), a pulling component 120, a motion component 130 and a control component (not shown in the figure).

[0029] The furnace body 110 can be used to accommodate at least some components (e.g., the chamber) of the crystal preparation apparatus 100. In some embodiments, the shape of the furnace body 110 can be cylindrical, cubic, or multi-prism (e.g., triangular, pentagonal, or hexagonal). In some embodiments, the furnace body 110 can be a sealed structure or a non-sealed structure. In some embodiments, the material of the furnace body 110 can include, but is not limited to, stainless steel or quartz.

[0030] In some embodiments, the furnace body 110 may include a furnace body 111, a furnace cover 112, and a bottom plate 113. The furnace cover 112 may be disposed on the top of the furnace body 111. The bottom plate 113 may be disposed on the bottom of the furnace body 111. In some embodiments, the furnace cover 112 and / or the bottom plate 113 may be sealed or unsealed from the outer wall of the furnace body 111.

[0031] In some embodiments, a heat-insulating tube (not shown) may be provided in the furnace body 110. At least a portion of the heat-insulating tube may be located in the furnace body 110. In some embodiments, the upper end of the heat-insulating tube may be flush with the upper surface of the furnace cover 112. In some embodiments, the upper end of the heat-insulating tube may be higher than the upper surface of the furnace cover 112. In some embodiments, the shape of the heat-insulating tube may be a cylinder, a cube, a polygonal prism (for example, a triangular prism, a pentagonal prism, a hexagonal prism), etc. In some embodiments, the material of the heat-insulating tube may include quartz (silicon oxide), corundum (aluminum oxide), zirconium oxide, graphite, carbon fiber, ceramics, etc., or other high-temperature resistant materials (for example, borides, carbides, nitrides, silicides, phosphides, and sulfides of rare earth metals, etc.). For example, the heat-insulating tube may be a quartz tube.

[0032] In some embodiments, an upper sealing cover may be provided at the upper end of the insulation cylinder. The upper sealing cover and the insulation cylinder may be sealed (e.g., glued or clamped with a sealing ring). In some embodiments, the upper sealing cover and the furnace cover 112 may be integrally formed. In some embodiments, an observation member may be provided on the upper sealing cover to allow observation of the interior of the insulation cylinder.

[0033] In some embodiments, the bottom end of the heat-insulating cylinder may be provided with a lower sealing cover. The lower sealing cover may be sealed to the heat-insulating cylinder (e.g., glued or clamped with a sealing ring). In some embodiments, the bottom end of the heat-insulating cylinder may not be provided with a lower sealing cover. For example, the bottom end of the heat-insulating cylinder may be sealed to the bottom plate 113.

[0034] The cavity can be used to place the raw materials required for growing crystals. In some embodiments, the cavity can be located inside the furnace body 110 (for example, inside the heat preservation tube). In some embodiments, the cavity can include a cooling structure to reduce the temperature of the cavity to prevent the cavity from volatilizing due to high temperature and contaminating the raw materials (for example, raw material melt), thereby further ensuring the quality of the grown crystals. For relevant descriptions of the cavity, please refer to other parts of this specification (for example, Figure 2 and its description), which will not be repeated here.

[0035] In some embodiments, the crystal preparation apparatus 100 may further include a heat preservation component (not shown). In some embodiments, the heat preservation component may at least partially surround the cavity. For example, the heat preservation component may be located inside the heat preservation cylinder and arranged around the periphery of the cavity. For relevant descriptions of the heat preservation component, please refer to other parts of this specification (for example, Figure 3 and its description), which will not be repeated here.

[0036] The heating assembly can be used to heat the raw material to provide the heat (eg, a temperature field) required for crystal preparation. In some embodiments, the heating assembly can include a laser heating assembly.

[0037] In some embodiments, the laser heating assembly may include at least two laser emitting units for emitting laser light and providing a heat source. In some embodiments, the laser heating assembly may also include at least two laser shaping collimators for adjusting the shape and / or size of the laser beams emitted by the at least two laser emitting units. In some embodiments, the at least two laser shaping collimators correspond to the positions of the at least two laser emitting units. For example, the at least two laser shaping collimators may be installed in the paths of the laser beams emitted by the at least two laser emitting units.

[0038] In some embodiments, the laser heating assembly can be installed on the furnace cover 112 or the upper sealing cover above the cavity. In some embodiments, the laser output ports of the at least two laser emitting units can correspond to the interior of the cavity to heat the raw materials in the cavity. For the arrangement of the at least two laser emitting units on the furnace cover 112 or the upper sealing cover, please refer to other parts of this specification (for example, Figure 4A 、 Figure 4B 、 Figure 5 and its description), which will not be repeated here.

[0039] The lifting assembly 120 can move up and down and / or rotate to grow crystals. The motion assembly 130 can drive the lifting assembly 120 to move up and down and / or rotate. In some embodiments, one end of the lifting assembly 120 can pass through holes in the upper sealing cover and the furnace cover 112 and move up and down and / or rotate. The other end of the lifting assembly 120 can be in transmission connection with the motion assembly 130.

[0040] In some embodiments, a sealing sleeve 121 may be provided on the outside of the lifting assembly 120. One end of the sealing sleeve 121 may be connected to the insulation barrel through a through-hole in the upper sealing cover, or to the furnace body 110 through a through-hole in the furnace cover 112. The other end of the sealing sleeve 121 may be sealed to the motion assembly 130 (e.g., welded, glued, or bolted). In some embodiments, the sealing sleeve 121 may provide a sealed environment for the lifting assembly 120. In some embodiments, the air pressure environment within the sealing sleeve 121 may be the same as or different from the air pressure environment within the insulation barrel.

[0041] In some embodiments, the crystal preparation apparatus 100 may further include a vacuum assembly that can be used to place the interior of the furnace body 110, the insulation cylinder, and / or the cavity in a vacuum environment or an air pressure environment below standard atmospheric pressure. In some embodiments, the vacuum assembly can be connected to the insulation cylinder through the through-holes and pipes on the upper sealing cover, or connected to the furnace body 110 through the through-holes and pipes on the furnace cover 112. In some embodiments, the vacuum assembly may include a power component (e.g., a mechanical pump) and a gas storage component (e.g., a gas storage bottle) for vacuuming and introducing gas (e.g., inert gas), respectively.

[0042] In some embodiments, the crystal preparation device 100 may further include a furnace rack 140 for supporting components such as the furnace body 110. In some embodiments, the furnace rack 140 may be arranged at the bottom of the furnace body 110. In some embodiments, the furnace rack 140 and the furnace body 110 may be integrally formed or fixedly connected (e.g., bolted, welded, or hinged). In some embodiments, the furnace body 110 may be placed directly on the furnace rack 140. In some embodiments, the furnace rack 140 may be a cubic or cylindrical steel frame structure. In some embodiments, the legs of the furnace rack 140 may be circular or square steel pipes. In some embodiments, the furnace rack 140 may also be other reasonable structures well known to those skilled in the art, and this specification does not limit this.

[0043] In some embodiments, the crystal preparation apparatus may further include a tray assembly (not shown) for supporting the chamber and the heat preservation assembly. In some embodiments, the tray assembly may be disposed on the lower sealing cover or the bottom plate 113. In some embodiments, the tray assembly may be made of quartz (silicon oxide), corundum (aluminum oxide), zirconium oxide, graphite, carbon fiber, ceramic, or other high-temperature resistant materials such as borides, carbides, nitrides, silicides, phosphides, and sulfides of rare earth metals.

[0044] In some embodiments, the crystal preparation apparatus 100 may further include a moving assembly 150 for driving the cavity to move. In some embodiments, the moving assembly 150 may include a moving rod 151 and a driving component 152. In some embodiments, the moving rod 151 may be fixedly connected to the cavity. In some embodiments, the driving component 152 may include, but is not limited to, a linear transmission mechanism, a hinge transmission mechanism, a rack and pinion transmission mechanism, a screw and nut transmission mechanism, and the like. The driving component 152 is connected to the moving rod 151 for driving the moving rod 151 to move (e.g., up and down) to drive the cavity to move.

[0045] In some embodiments, the control component can adjust the heating parameters of the heating component (e.g., a laser heating component) in real time during the crystal growth process. In some embodiments, the control component can adjust the temperature gradient during the crystal growth process in real time by controlling the heating parameters of the laser heating component. In some embodiments, the temperature gradient can include a radial temperature gradient and / or an axial temperature gradient. In some embodiments, the control component can also adjust the temperature value of a specific position (e.g., a specific raw material position in the cavity, a specific melt position, a solid-liquid interface between the melt and the raw material) during the crystal growth process, the average temperature of multiple positions, the temperature variance of multiple positions, the melt temperature distribution (e.g., a temperature distribution curve, a temperature distribution diagram), the raw material temperature distribution, the temperature distribution in the cavity, etc., or any combination thereof, in real time by controlling the heating parameters of the laser heating component.

[0046] In the embodiments of this specification, temperature distribution can reflect the distribution of temperature in time and space. Unless otherwise specified, temperature distribution, temperature field, temperature field distribution and temperature field information can be used interchangeably.

[0047] In some embodiments, the heating parameters of the laser heating assembly may include the shape, size, etc. of the laser beam or any combination thereof. In some embodiments, the heating parameters of the laser heating assembly may also include the operating power of at least two laser emitting units. For relevant descriptions of how the control assembly adjusts the temperature gradient, the temperature value at a specific location, the average temperature at multiple locations, the temperature variance at multiple locations, the melt temperature distribution, etc. during the crystal growth process in real time by controlling the heating parameters of the laser heating assembly, please refer to other parts of this specification (for example, Figure 6 and its description), which will not be repeated here.

[0048] In some embodiments, the control component may include a central processing unit (CPU), an application-specific integrated circuit (ASIC), an application-specific instruction set processor (ASIP), a graphics processing unit (GPU), a physical processing unit (PPU), a digital signal processor (DSP), a field programmable gate array (FPGA), a programmable logic device (PLD), a controller, a microcontroller unit, a reduced instruction set computer (RISC), a microprocessor, etc., or any combination thereof.

[0049] In some embodiments, the crystal preparation apparatus 100 may further include a temperature measurement component (not shown). In some embodiments, the temperature measurement component may include at least one temperature sensing component for measuring temperature information related to the raw material or cavity and sending the measured temperature information to the control component. In some embodiments, the temperature sensing component may include but is not limited to an infrared thermometer, a photoelectric pyrometer, a fiber optic radiation thermometer, a colorimetric thermometer, an ultrasonic thermometer, a microwave sensor, a thermocouple sensor, or the like, or any combination thereof. In some embodiments, the temperature information related to the raw material or cavity may include but is not limited to the temperature value of a specific position in the raw material or cavity (e.g., a specific raw material position in the cavity, a specific melt position, or the intersection of the melt and the raw material), the average temperature of multiple positions, the temperature variance of multiple positions, the melt temperature distribution (e.g., a temperature distribution curve, a temperature distribution graph), the raw material temperature distribution or the temperature distribution in the cavity, or any combination thereof.

[0050] In some embodiments, the control component can adjust the heating parameters of the laser heating component in real time based on temperature information related to the raw material or the cavity to grow high-quality crystals.

[0051] In some embodiments, the control component can perform simulation modeling based on temperature information related to the raw material or the cavity, and further adjust the heating parameters of the laser heating component in real time based on the simulation results. In some embodiments, the control component can construct a temperature model using finite element analysis, MATLAB, regression methods, artificial neural networks, support vector machines, etc., and adjust the heating parameters of the laser heating component in real time based on the temperature model. In some embodiments, the temperature model can reflect the global or overall temperature distribution within the cavity. In some embodiments, the temperature model can reflect the temperature gradient within the cavity (e.g., axial temperature gradient, radial temperature gradient).

[0052] In some embodiments, if the temperature model indicates that the temperature at a certain location is lower than or higher than a preset temperature, the control component may increase or decrease the operating power of at least two laser emitting units to ensure that the temperature at that location is consistent with or substantially consistent with the preset temperature, or to ensure that the temperature difference between the two is within a preset range (e.g., 0.01% of the preset temperature). For example, if the temperature model indicates that the temperature at the solid-liquid interface between the growing crystal and the raw material melt is lower than or higher than a preset ideal growth temperature (which may be a system default or user-set), the control component may increase or decrease the operating power of at least two laser emitting units.

[0053] In some embodiments, if the temperature model indicates that the temperature at a certain location is lower than or higher than a preset temperature, the control component may adjust the at least two laser shaping collimators to adjust the size and / or shape of the laser beams emitted by the at least two laser emitting units so that the temperature at that location is consistent or substantially consistent with the preset temperature, or so that the temperature difference between the two is within a preset range (e.g., 0.01% of the preset temperature). For example, if the temperature model indicates that the temperature at the solid-liquid interface between the growing crystal and the raw material melt is lower than or higher than a preset temperature, the control component may adjust the at least two laser shaping collimators to reduce or increase the size of the laser beams emitted by the at least two laser emitting units or adjust the shape of the laser beams.

[0054] In some embodiments, if the temperature model indicates that the temperature gradient (e.g., radial temperature gradient) is too large or too small, the control component can adjust the heating parameters of at least two laser emission units to adjust the temperature gradient in real time. Figure 6 The description thereof will not be repeated here.

[0055] In some embodiments, the control component can train a machine learning model based on historical crystal growth information (e.g., historical temperature information related to the raw material or cavity, historical heating parameters of the laser heating component, and historical crystal-related parameters). The input of the machine learning model can include crystal-related parameters (e.g., crystal type, crystal size, crystal properties, the stage of crystal growth, etc.), and the output can include temperature information related to the raw material or cavity and / or the heating parameters of the laser heating component. In some embodiments, the control component can monitor the crystal-related parameters in real time and determine the required temperature information related to the raw material or cavity and / or the ideal heating parameters of the laser heating component based on the trained machine learning model. Furthermore, the control component can automatically adjust the heating parameters of the laser heating component based on the required temperature information related to the raw material or cavity and / or the ideal heating parameters of the laser heating component, thereby realizing intelligent real-time temperature field adjustment during the crystal growth process.

[0056] For the description of the control component adjusting the heating parameters of the laser heating component in real time based on the temperature information, please refer to other parts of this specification (for example, Figure 6 and its description), which will not be repeated here.

[0057] In some embodiments, the crystal preparation apparatus 100 may further include a feeding assembly (not shown) for feeding in real time (e.g., automatically) during the crystal growth process. This real-time feeding can substantially maintain the melt concentration in the chamber during crystal growth, thereby ensuring that the grown crystal has high uniformity from top to bottom.

[0058] In some embodiments, the feeding assembly may include a weighing component, a mixing component, and a transferring component.

[0059] The weighing component can be used to weigh the weight information of the growing crystal and / or the weight information of the supplementary material, and send it to the control component. In some embodiments, the weighing component may include at least one weighing sensor. In some embodiments, the weighing sensor may include but is not limited to a photoelectric sensor, a hydraulic sensor, an electromagnetic force sensor, a capacitive sensor, a magnetic pole variation sensor, a vibration sensor, a gyroscopic sensor, a resistance strain sensor, etc. or any combination thereof. In some embodiments, the control component can obtain the weight information of the growing crystal, and determine the relevant information of the supplementary material based on at least the weight information and the ratio of the raw materials (for example, between each reaction material) used to grow the crystal. In some embodiments, the relevant information of the supplementary material may include but is not limited to the composition of the supplementary material and the weight of each component. In some embodiments, the control component can control the weighing component to weigh each supplementary material component respectively.

[0060] The mixing component can be used to mix the supplement evenly. In some embodiments, the control component can control the mixing component to mix the various supplement ingredients evenly.

[0061] The material transfer component can transfer the supplemental material from the mixing component to the cavity. In some embodiments, the material transfer component can include a transmission element and a power element, and the power element and the transmission element can be in transmission connection. In some embodiments, the transmission element can include but is not limited to a gear conveyor belt. In some embodiments, the power element can include but is not limited to a motor.

[0062] In some embodiments, the crystal preparation apparatus 100 may further include a liquid level sensor (not shown) for measuring liquid level position information (eg, liquid level height information) of the melt in the cavity and sending the liquid level position information to the control component.

[0063] In some embodiments, during the crystal growth process, the control component can control the movement of the moving component 150 based on the liquid level position information to control the movement of the cavity, and further maintain the distance between the at least two laser emitting units and the melt liquid surface constant or substantially constant. This can avoid the change in the size of the light beams emitted by the at least two laser emitting units at the melt liquid surface due to the drop in the melt liquid level during the crystal growth process, which further causes the temperature field to change and affects the normal growth of the crystal.

[0064] In some embodiments, the crystal preparation apparatus 100 may further include a display assembly (not shown). In some embodiments, the display assembly may display information related to crystal growth in real time, such as temperature information related to the raw materials or the chamber, weight information of the growing crystal, information related to the replenishment material, heating parameters of the laser heating assembly, the pulling speed and / or rotation speed of the pulling assembly 120, and the appearance of the crystal. In some embodiments, the display assembly may include a liquid crystal display, a plasma display, a light-emitting diode display, or any combination thereof.

[0065] In some embodiments, the crystal preparation apparatus 100 may further include a storage component (not shown). The storage component may store data, instructions and / or any other information. In some embodiments, the storage component may store data and / or information involved in the crystal preparation process. For example, the storage component may store temperature information related to the raw material or cavity involved in the crystal preparation process, relevant information about the supplementary material, heating parameters of the laser heating component and / or data and / or instructions for completing the exemplary crystal preparation method described in the embodiments of this specification. In some embodiments, the storage component may include a USB flash drive, a mobile hard drive, an optical disk, a memory card, etc., or any combination thereof.

[0066] It should be noted that the above description of the crystal preparation device 100 is only for illustration and explanation, and does not limit the scope of application of this specification. For those skilled in the art, various modifications and changes can be made to the crystal preparation device 100 under the guidance of this specification. However, these modifications and changes are still within the scope of this specification. For example, the crystal preparation device 100 can be open, the furnace body 110 can be opened, and the operator (for example, a worker) can directly observe the insulation cylinder inside the furnace body 110. The insulation cylinder is sealed and has no gas exchange with the atmospheric environment. For another example, the crystal preparation device 100 can be a vacuum type, the interior of the furnace body 110 is in a vacuum state, and the crystal preparation device 100 has no gas exchange with the atmospheric environment.

[0067] Figure 2 is a schematic structural diagram of an exemplary cavity according to some embodiments of this specification.

[0068] In some embodiments, as Figure 2As shown, the chamber 200 may include a cooling structure 210 for reducing the temperature of the chamber 200 to prevent the high temperature volatilization of the chamber 200 from contaminating the raw materials (e.g., raw material melt), thereby further ensuring the quality of the grown crystal. In some embodiments, a cooling medium (e.g., cooling gas, cooling water, cooling oil) may be passed through the cooling structure 210 to achieve a cooling effect on the chamber 200.

[0069] In some embodiments, the cavity 200 may be a single cavity having a hollow structure, which may constitute the cooling structure 210 .

[0070] In some embodiments, as Figure 2 As shown, the cavity 200 may include an inner cavity 220 and an outer cavity 230, and the inner cavity 220 and the outer cavity 230 may be arranged to form a cooling structure 210. In some embodiments, the inner cavity 220 and the outer cavity 230 may be integrally formed or fixedly connected (e.g., by welding, gluing, etc.). In some embodiments, the inner cavity 220 and the outer cavity 230 may be detachably connected (e.g., by snap-fitting, etc.) to facilitate replacement (e.g., of the inner cavity 220 or the outer cavity 230), thereby reducing the cost of the cavity 200 and further reducing the cost of crystal preparation.

[0071] In some embodiments, as Figure 2 As shown, the cooling structure 210 may include at least one inlet 211, at least one outlet 212, and a cooling channel 213. In some embodiments, a cooling medium may enter the cooling channel 213 from the at least one inlet 211 and then flow out from the at least one outlet 212 to reduce the temperature of the portion of the cavity 200 near the feedstock. In some embodiments, the height of the at least one inlet 211 may be lower than the height of the at least one outlet 212 to improve the utilization of the cooling medium.

[0072] In some embodiments, the material of the cavity 200 may include metal materials such as copper, iron, and stainless steel to reduce the cost of the cavity 200 and further reduce the cost of preparing the crystal while ensuring the quality of the crystal. In some embodiments, the material of the cavity 200 may also include graphite, quartz, alumina, or zirconium oxide. In some embodiments, the material of the inner cavity 220 and the outer cavity 230 may be the same or different. For example, the material of the inner cavity 220 and the outer cavity 230 may both be copper. For another example, the material of the inner cavity 220 is copper, and the material of the outer cavity 230 is graphite. The embodiments of this specification do not impose any restrictions on the purity of the material of the cavity 200.

[0073] Figure 3 It is a schematic structural diagram of an exemplary cavity and insulation component shown in some embodiments of this specification.

[0074] In some embodiments, the heat preservation assembly 300 may at least partially surround the cavity 200. For example, Figure 3 As shown, the heat preservation component 300 can be disposed around the periphery of the cavity 200 .

[0075] In some embodiments, as Figure 3 As shown, the heat preservation assembly 300 may include an upper heat preservation component 310 , a middle heat preservation component 320 and a lower heat preservation component 330 .

[0076] In some embodiments, the upper heat-insulating component 310 may include a first gap 311 to allow at least a portion of the lifting assembly 120 to extend into the chamber 200 for vertical movement and / or rotation to grow crystals. In some embodiments, the upper heat-insulating component 310 may also include at least two through-holes 312 to facilitate the entry of laser beams emitted by the at least two laser emitting units into the chamber 200. In some embodiments, the at least two through-holes 312 may correspond to the at least two laser emitting units and be arranged in the same manner.

[0077] In some embodiments, the middle heat-insulating component 320 may be disposed around the cavity 200. The middle heat-insulating component 320 may be tightly connected to the upper heat-insulating component 310 and the lower heat-insulating component 330.

[0078] In some embodiments, the lower insulation component 330 may be disposed around the outer wall of the cavity 200 to insulate the cavity 200. In some embodiments, insulation components may not be disposed at at least one inlet 211 and at least one outlet 212 to facilitate the cooling medium to enter and exit the cooling channel 213.

[0079] In some embodiments, the insulation assembly 300 can be made of bulk insulation material, flocculent insulation material, or sheet insulation material. In some embodiments, the insulation assembly 300 can be made of high-temperature resistant materials such as metal, aluminum oxide, zirconium oxide, silicon oxide, tempered aluminum, carbide, nitride, or silicide. In some embodiments, the upper insulation component 310, the middle insulation component 320, and the lower insulation component 330 can be made of the same or different materials.

[0080] In some embodiments, the crystal preparation apparatus may further include a tray assembly 400 for supporting the chamber 200 and the heat preservation assembly 300. In some embodiments, the tray assembly 400 may include a tray through hole 410 connected to at least one inlet 211 to facilitate the flow of cooling medium into the cooling channel 213.

[0081] Figure 4A is a top view of an exemplary furnace cover according to some embodiments of the present specification. Figure 4B is a top view of an exemplary furnace cover according to some other embodiments of the present specification.

[0082] In some embodiments, as Figure 4A and Figure 4B As shown, the furnace cover 112 may be provided with a first through hole 1121, and at least a portion of the pulling assembly 120 may extend into the furnace body 110 or the cavity through the first through hole 1121 to move up and down and / or rotate to grow crystals (for example, Figure 2 and Figure 6 In some embodiments, the concentricity between the first through hole 1121 and the cavity may be less than 10 mm. In some embodiments, the concentricity between the first through hole 1121 and the cavity may be less than 8 mm. In some embodiments, the concentricity between the first through hole 1121 and the cavity may be less than 6 mm. In some embodiments, the concentricity between the first through hole 1121 and the cavity may be less than 4 mm. In some embodiments, the concentricity between the first through hole 1121 and the cavity may be less than 2 mm.

[0083] In some embodiments, as Figure 4A and Figure 4B As shown, at least two laser emitting units 500 may be mounted on the furnace cover 112. In some embodiments, the at least two laser emitting units 500 may be distributed circumferentially along the furnace cover 112. In some embodiments, the at least two laser emitting units 500 may be distributed circumferentially along the furnace cover 112 to form at least one annular shape, so as to precisely adjust the temperature gradient (e.g., radial temperature gradient) required for crystal growth during the crystal growth process. For example, Figure 4A As shown, at least two laser emitting units 500 can be circumferentially distributed on the furnace cover 112 with the first through hole 1121 as the center to form a ring shape (such as Figure 4A As shown by the dotted line a). For another example, Figure 4B As shown, at least two laser emitting units 500 can be centered on the first through hole 1121 and circumferentially distributed on the furnace cover 112 to form two annular shapes (respectively as Figure 4B (shown by the dashed lines b1 and b2).

[0084] In some embodiments, at least two laser emitting units 500 are circumferentially distributed to form an outermost annular shape (eg, Figure 4A As shown by the dotted line a, Figure 4B The radius of the cavity (shown by the dotted line b1) can be smaller than the radius of the cavity, so that the laser beams emitted by at least two laser emitting units 500 can avoid the cavity side wall temperature being too high as much as possible while providing the temperature field required for crystal growth, and further avoid the cavity volatilization affecting the crystal quality. Figure 2As shown, because the radius of the outermost annular shape formed by the circumferential distribution of at least two laser emitting units 500 is smaller than the radius of the cavity, the raw material near the center of the cavity 200 and near the annular shape melts to form melt A, while the raw material B near the sidewall of the cavity 200 does not melt. This annular heating method can prevent the cavity 200 from volatilizing due to excessive temperature and contaminating the raw material.

[0085] The radius of the outermost annular shape formed by the circumferential distribution of at least two laser emitting units 500 (eg Figure 4B The difference between the radius of the outermost annular shape and the radius of the cavity will affect the utilization rate of the raw materials and the quality of the crystal. For example, if the difference between the radius of the outermost annular shape and the radius of the cavity is too large, most of the raw materials in the cavity will not be melted to form a melt, which will further lead to a low utilization rate of the raw materials. For another example, if the difference between the radius of the outermost annular shape and the radius of the cavity is too small, the temperature of the side wall of the cavity will be too high, causing it to volatilize, further contaminating the raw materials in the cavity (for example, raw material melt), and affecting the quality of the crystal. Therefore, in some embodiments, in order to improve the utilization rate of the raw materials and ensure the quality of the crystal, the difference between the radius of the outermost annular shape and the radius of the cavity must meet the preset requirements.

[0086] In some embodiments, the difference between the radius of the outermost annular shape and the radius of the cavity may be within a range of 50 mm to 500 mm. In some embodiments, the difference between the radius of the outermost annular shape and the radius of the cavity may be within a range of 100 mm to 500 mm. In some embodiments, the difference between the radius of the outermost annular shape and the radius of the cavity may be within a range of 120 mm to 480 mm. In some embodiments, the difference between the radius of the outermost annular shape and the radius of the cavity may be within a range of 150 mm to 450 mm. In some embodiments, the difference between the radius of the outermost annular shape and the radius of the cavity may be within a range of 180 mm to 420 mm. In some embodiments, the difference between the radius of the outermost annular shape and the radius of the cavity may be within a range of 200 mm to 400 mm. In some embodiments, the difference between the radius of the outermost annular shape and the radius of the cavity may be within a range of 220 mm to 380 mm. In some embodiments, the difference between the radius of the outermost annular shape and the radius of the cavity may be within a range of 250 mm to 350 mm. In some embodiments, the difference between the radius of the outermost annular shape and the radius of the cavity may be within a range of 280 mm to 320 mm. In some embodiments, the difference between the radius of the outermost annular shape and the radius of the cavity may be in the range of 50 mm-200 mm. In some embodiments, the difference between the radius of the outermost annular shape and the radius of the cavity may be in the range of 50 mm-100 mm. In some embodiments, the difference between the radius of the outermost annular shape and the radius of the cavity may be in the range of 100 mm-200 mm. In some embodiments, the difference between the radius of the outermost annular shape and the radius of the cavity may be in the range of 400 mm-500 mm. In some embodiments, the difference between the radius of the outermost annular shape and the radius of the cavity may be in the range of 400 mm-450 mm. In some embodiments, the difference between the radius of the outermost annular shape and the radius of the cavity may be in the range of 450 mm-500 mm.

[0087] In some embodiments, the difference between the radius of the outermost annular shape and the radius of the cavity may be 0.5 times to 5 times the diameter of the crystal to be grown. In some embodiments, the difference between the radius of the outermost annular shape and the radius of the cavity may be 1 times to 4.5 times the diameter of the crystal to be grown. In some embodiments, the difference between the radius of the outermost annular shape and the radius of the cavity may be 1.5 times to 4 times the diameter of the crystal to be grown. In some embodiments, the difference between the radius of the outermost annular shape and the radius of the cavity may be 2 times to 3.5 times the diameter of the crystal to be grown. In some embodiments, the difference between the radius of the outermost annular shape and the radius of the cavity may be 2.5 times to 3 times the diameter of the crystal to be grown.

[0088] The radius of the outermost annular shape formed by the circumferential distribution of at least two laser emitting units 500 (eg Figure 4BThe outermost annular shape (shown as R in the figure) will affect the quality of the crystal. For example, if the radius of the outermost annular shape is too small, the thermal stress inside the growing crystal will be greater, which will further cause the crystal to crack easily. For another example, if the radius of the outermost annular shape is too large, more melt will be formed by melting the raw materials inside the cavity. The flow rate of the melt will affect the crystal growth interface, further resulting in more stripes on the surface of the growing crystal, affecting the optical uniformity of the crystal. Therefore, in some embodiments, in order to improve the quality of the crystal, the radius of the outermost annular shape must meet the preset requirements.

[0089] In some embodiments, the radius of the outermost annular shape may be 1.21 times to 3.5 times the diameter of the crystal to be grown. In some embodiments, the radius of the outermost annular shape may be 1.5 times to 3.2 times the diameter of the crystal to be grown. In some embodiments, the radius of the outermost annular shape may be 1.8 times to 3 times the diameter of the crystal to be grown. In some embodiments, the radius of the outermost annular shape may be 2 times to 2.8 times the diameter of the crystal to be grown. In some embodiments, the radius of the outermost annular shape may be 2.2 times to 2.6 times the diameter of the crystal to be grown. In some embodiments, the radius of the outermost annular shape may be 2.3 times to 2.5 times the diameter of the crystal to be grown.

[0090] The radius of the innermost annular shape formed by the circumferential distribution of at least two laser emitting units 500 (eg Figure 4B The innermost annular shape (shown as r in the figure) may affect crystal growth. For example, if the radius of the innermost annular shape is too large, the raw material near the center of the cavity cannot be melted to form a melt or the melt is insufficient, further resulting in the inability to grow crystals. For another example, if the radius of the innermost annular shape is too small, the temperature of the raw material near the center of the cavity is too high, further resulting in the inability to crystallize the melt and grow crystals. Therefore, in some embodiments, in order for the crystal to grow normally, the radius of the innermost annular shape must meet the preset requirements.

[0091] In some embodiments, the radius of the innermost annular shape may be in the range of 25 mm to 300 mm. In some embodiments, the radius of the innermost annular shape may be in the range of 30 mm to 270 mm. In some embodiments, the radius of the innermost annular shape may be in the range of 50 mm to 250 mm. In some embodiments, the radius of the innermost annular shape may be in the range of 70 mm to 230 mm. In some embodiments, the radius of the innermost annular shape may be in the range of 100 mm to 200 mm. In some embodiments, the radius of the innermost annular shape may be in the range of 120 mm to 180 mm. In some embodiments, the radius of the innermost annular shape may be in the range of 150 mm to 160 mm. In some embodiments, the radius of the innermost annular shape may be in the range of 20 mm to 100 mm. In some embodiments, the radius of the innermost annular shape may be in the range of 20 mm to 50 mm. In some embodiments, the radius of the innermost annular shape may be in the range of 50 mm to 100 mm. In some embodiments, the radius of the innermost annular shape may be in the range of 200 mm to 300 mm. In some embodiments, the radius of the innermost annular shape may be in the range of 200 mm to 250 mm. In some embodiments, the radius of the innermost annular shape may be in the range of 25 mm - 300 mm.

[0092] In some embodiments, the radius of the innermost annular shape may be 1.2 to 3 times the diameter of the crystal to be grown. In some embodiments, the radius of the innermost annular shape may be 1.4 to 2.8 times the diameter of the crystal to be grown. In some embodiments, the radius of the innermost annular shape may be 1.6 to 2.6 times the diameter of the crystal to be grown. In some embodiments, the radius of the innermost annular shape may be 1.8 to 2.4 times the diameter of the crystal to be grown. In some embodiments, the radius of the innermost annular shape may be 2 to 2.2 times the diameter of the crystal to be grown.

[0093] The distance between adjacent annular shapes in at least two annular shapes formed by the circumferential distribution of at least two laser emitting units 500 (eg Figure 4BThe difference between R and r in the figure will affect the control of the temperature field (or temperature gradient) and / or the installation of at least two laser emitting units 500. For example, if the spacing between adjacent annular shapes is too large, the radial temperature gradient cannot be accurately controlled, further affecting the crystal quality. For another example, if the spacing between adjacent annular shapes is too small, it will be difficult to install at least two laser emitting units 500. In addition, if the spacing between adjacent annular shapes is too small, it may be difficult to accurately control the overlap of the laser beams emitted by the laser emitting units on adjacent rings, which will in turn make it impossible to accurately control the radial temperature gradient. Therefore, in some embodiments, in order to ensure the crystal quality and facilitate the installation of at least two laser emitting units 500, the spacing between adjacent annular shapes must meet the preset requirements.

[0094] In some embodiments, the spacing between adjacent annular shapes may be within the range of 5 mm to 200 mm. In some embodiments, the spacing between adjacent annular shapes may be within the range of 20 mm to 180 mm. In some embodiments, the spacing between adjacent annular shapes may be within the range of 40 mm to 160 mm. In some embodiments, the spacing between adjacent annular shapes may be within the range of 60 mm to 140 mm. In some embodiments, the spacing between adjacent annular shapes may be within the range of 80 mm to 120 mm. In some embodiments, the spacing between adjacent annular shapes may be within the range of 50 mm to 200 mm. In some embodiments, the spacing between adjacent annular shapes may be within the range of 50 mm to 100 mm.

[0095] Figure 5 This is a schematic diagram of the installation structure of at least two laser emitting units according to some embodiments of this specification. Figure 4A , Figure 5 Shown Figure 4A Partial AA section view, Figure 5 Not shown are at least two laser emitting units.

[0096] In some embodiments, as Figure 5 As shown, at least two laser input windows 1122 can be provided on the furnace cover 112 for mounting at least two laser shaping collimating lenses. The at least two laser input windows 1122 can correspond to the laser output ports of at least two laser emitting units, so that the laser beams emitted by the at least two laser emitting units can be input into the cavity 200.

[0097] In some embodiments, as Figure 5 As shown, the laser input window 1122 may include a laser input window top cover 11221 , a laser input window column 11222 and a connector 11223 .

[0098] In some embodiments, the laser input window top cover 11221 may be provided with a second through hole for mounting a window (e.g., glass). In some embodiments, the laser input window top cover 11221 may not include the second through hole and may be an integrated window structure. In some embodiments, the laser input window top cover 11221 and the laser input window column 11222 may be detachably connected (e.g., bolted). In some embodiments, the laser input window top cover 11221 and the laser input window column 11222 may be sealedly connected via a sealing ring. In some embodiments, a connector 11223 may be disposed within the laser input window column 11222 and located below the laser input window top cover 11221. In some embodiments, the material of the connector 11223 may include, but is not limited to, quartz, and is used to transmit the laser beam so that it is incident into the cavity 200 to heat the raw material.

[0099] In some embodiments, the furnace cover 112 may further include a cooling passage 1123 for introducing a cooling medium (e.g., cooling gas, cooling water, or cooling oil) to reduce the temperature of the furnace cover 112. In some embodiments, the furnace cover 112 may further include a passage inlet 1124 and a passage outlet 1125. The cooling medium may enter the cooling passage 1123 through the passage inlet 1124 and then exit through the passage outlet 1125. In some embodiments, the height of the passage inlet 1124 may be lower than the height of the passage outlet 1125 to improve the utilization rate of the cooling medium.

[0100] In some embodiments, the first through hole 1121 , the at least two laser input windows 1122 , and the cooling passage 1123 may be independent of each other or not connected.

[0101] In some embodiments, as Figure 5 As shown, the furnace cover 112 may further be provided with a passage 1126 for the pulling assembly 120 to pass through for vertical movement and / or rotational movement. The passage 1126 is communicated with the first through hole 1121 .

[0102] Figure 6 FIG. 1 is a schematic diagram of the temperature field distribution inside the cavity according to some embodiments of this specification. Figure 2 , Figure 6 It can be understood as Figure 2 Top view of .

[0103] In some embodiments, during the crystal growth process, the temperature gradient includes an axial temperature gradient and / or a radial temperature gradient. The radial temperature gradient is used as an example for description below.

[0104] In some embodiments, the radial temperature gradient during the crystal growth process may include a first temperature gradient and a second temperature gradient, wherein the first temperature gradient may refer to the temperature gradient from the annular heating zone to the center point of the crystal growth (e.g., Figure 6Center point O) direction (for example, Figure 6 The second temperature gradient may refer to the direction from the annular heating zone to the inner wall of the cavity (for example, Figure 6 In some embodiments, the first and second temperature gradients are both negative by controlling the heating parameters of the laser heating assembly. This means that the temperature gradually decreases from the annular heating zone toward the center of crystal growth, thereby providing momentum for crystal growth. Furthermore, the temperature gradually decreases from the annular heating zone toward the inner wall of the cavity, thereby preventing contamination of the raw materials caused by volatilization of the cavity wall.

[0105] In some embodiments, in combination with the above, at least two laser emitting units can be distributed along the circumference of the furnace cover to form multiple annular shapes. Accordingly, the annular heating zone can include multiple sub-annular areas, each corresponding to the multiple annular shapes. In some embodiments, the temperature of the multiple sub-annular areas gradually decreases from the outside to the inside (i.e., from the annular heating zone to the center of crystal growth), thereby forming a negative temperature gradient in the x direction (i.e., the first temperature gradient). As an example only, in combination with Figure 4B , at least two laser emitting units are distributed along the circumference of the furnace cover to form two annular shapes b1 and b2, accordingly, as Figure 6 As shown, the two annular shapes b1 and b2 form two annular regions Y and Z respectively, and the temperature of the annular region Y is higher than the temperature of the annular region Z.

[0106] In some embodiments, during the crystal growth process, the first temperature gradient and / or the second temperature gradient can be adjusted in real time by adjusting the heating parameters of at least two laser emitting units. In some embodiments, the heating parameters of the laser emitting unit may include the operating power of the laser emitting unit, the shape of the laser beam, the size of the laser beam, etc., or any combination thereof. In some embodiments, the temperature and / or range of the annular heating zone can be adjusted by adjusting the heating parameters of at least two laser emitting units, thereby adjusting the first temperature gradient and / or the second temperature gradient. In some embodiments, the temperature and / or range of the multiple sub-annular areas can be adjusted by respectively adjusting the heating parameters of the laser emitting units corresponding to the multiple sub-annular areas.

[0107] In some embodiments, the temperature of the annular heating zone (or multiple sub-annular zones) can be increased or decreased by increasing or decreasing the operating power of at least two laser emitting units, and the temperature gradient can be adjusted accordingly. By way of example only, during the crystal growth process, if the first temperature gradient (for ease of description, the absolute value of the temperature gradient is used as an example) is lower than a preset temperature gradient (which can be a system default value or set by the user), that is, the temperature gradient along the direction from the annular heating zone to the center of crystal growth is lower than the preset temperature gradient, the operating power of the laser emitting units corresponding to the outer sub-annular zones can be increased (to increase the temperature of the outer sub-annular zones) and / or the operating power of the laser emitting units corresponding to the inner sub-annular zones can be decreased (to decrease the temperature of the inner sub-annular zones), thereby increasing the first temperature gradient so that the first temperature gradient is consistent with or substantially consistent with the preset temperature gradient, or so that the difference between the two temperature gradients is within a preset range (e.g., 0.01% of the preset temperature gradient). As another example, during the crystal growth process, if the first temperature gradient is higher than the preset temperature gradient, that is, the temperature gradient along the annular heating zone to the center point of crystal growth is higher than the preset temperature gradient, the operating power of the laser emitting unit corresponding to the outer sub-annular area can be reduced (to reduce the temperature of the outer sub-annular area) and / or the operating power of the laser emitting unit corresponding to the inner sub-annular area can be increased (to increase the temperature of the inner sub-annular area), thereby reducing the first temperature gradient so that the first temperature gradient is consistent or basically consistent with the preset temperature gradient, or the temperature gradient difference between the two is within a preset range (for example, 0.01% of the preset temperature gradient).

[0108] In some embodiments, the size of the laser beams emitted by at least two laser emitting units can be adjusted by adjusting at least two laser shaping collimators to adjust the temperature of the annular heating zone (or multiple sub-annular zones), thereby adjusting the temperature gradient. By way of example only, during crystal growth, if a first temperature gradient (for ease of description, the absolute value of the temperature gradient is used as an example) is lower than a preset temperature gradient (which can be a system default value or user-set), that is, the temperature gradient along the direction from the annular heating zone to the center of crystal growth is lower than the preset temperature gradient, the laser shaping collimators corresponding to the outer sub-annular zones can be adjusted to reduce the size of the corresponding laser beams (to more concentrate the laser beam energy to increase the temperature of the outer sub-annular zones) and / or the laser shaping collimators corresponding to the inner sub-annular zones can be adjusted to increase the size of the corresponding laser beams (to diverge the laser beam energy (assuming adjacent laser beams do not overlap) to reduce the temperature of the inner sub-annular zones), thereby increasing the first temperature gradient so that the first temperature gradient is consistent with or substantially consistent with the preset temperature gradient, or so that the difference between the two temperature gradients is within a preset range (e.g., 0.01% of the preset temperature gradient). As another example, if the first temperature gradient is higher than the preset temperature gradient, that is, the temperature gradient along the direction from the annular heating zone to the center point of crystal growth is higher than the preset temperature gradient, the laser shaping collimator corresponding to the outer sub-annular area can be adjusted to increase the size of the corresponding laser beam (diverge the energy of the laser beam (assuming that adjacent laser beams do not overlap) to reduce the temperature of the outer sub-annular area) and / or adjust the laser shaping collimator corresponding to the inner sub-annular area to reduce the size of the corresponding laser beam (make the energy of the laser beam more concentrated to increase the temperature of the inner sub-annular area), thereby reducing the first temperature gradient so that the first temperature gradient is consistent or basically consistent with the preset temperature gradient, or the temperature gradient difference between the two is within a preset range (for example, 0.01% of the preset temperature gradient).

[0109] In some embodiments, the size and / or shape of the laser beams emitted by at least two laser emitting units can be adjusted by adjusting at least two laser shaping collimators to thereby adjust the overlap of the beams, thereby adjusting the temperature of the annular heating zone (or multiple sub-annular zones), and accordingly, adjusting the temperature gradient. By way of example only, during the crystal growth process, if the first temperature gradient (for ease of description, the absolute value of the temperature gradient is used as an example) is lower than a preset temperature gradient (which can be a system default value or set by the user), that is, the temperature gradient along the direction from the annular heating zone to the center of crystal growth is lower than the preset temperature gradient, the laser shaping collimators corresponding to the outer sub-annular zones can be adjusted to change the size and / or shape of the corresponding laser beams so that adjacent laser beams at least partially overlap (to increase the temperature of the outer sub-annular zones) and / or the laser shaping collimators corresponding to the inner sub-annular zones can be adjusted to change the size and / or shape of the corresponding laser beams so that adjacent laser beams overlap less (to reduce the temperature of the inner sub-annular zones), thereby increasing the first temperature gradient so that the first temperature gradient is consistent with or substantially consistent with the preset temperature gradient, or so that the difference between the two temperature gradients is within a preset range (e.g., 0.01% of the preset temperature gradient). As another example, during the crystal growth process, if the first temperature gradient is higher than the preset temperature gradient, that is, the temperature gradient along the annular heating zone to the center point of crystal growth is higher than the preset temperature gradient, the laser shaping collimator corresponding to the outer sub-annular area can be adjusted to change the size and / or shape of the corresponding laser beam so that the overlapping part between adjacent laser beams is reduced (to reduce the temperature of the outer sub-annular area) and / or the laser shaping collimator corresponding to the inner sub-annular area can be adjusted to change the size and / or shape of the corresponding laser beam so that adjacent laser beams at least partially overlap (to increase the temperature of the inner sub-annular area), thereby reducing the first temperature gradient so that the first temperature gradient is consistent or substantially consistent with the preset temperature gradient, or the temperature gradient difference between the two is within a preset range (for example, 0.01% of the preset temperature gradient).

[0110] In some embodiments, taking a sub-annular region as an example, the heating parameters of the multiple laser emitting units corresponding to the sub-annular region can be adjusted separately to achieve precise control of the temperature of each circumferential position on the sub-annular region. In some embodiments, the heating parameters (e.g., operating power, shape, size) of the multiple laser emitting units corresponding to adjacent sub-annular regions can also be adjusted in conjunction to achieve precise control of the temperature and / or range of adjacent sub-annular regions, thereby achieving continuous and precise control of the radial temperature gradient.

[0111] In some embodiments, simulation modeling can be performed based on temperature information related to the raw material or cavity, and the heating parameters of the laser heating assembly can be adjusted in real time based on the simulation results. In some embodiments, a temperature model can be constructed using finite element analysis, MATLAB, regression methods, artificial neural networks, support vector machines, etc., and the heating parameters of the laser heating assembly can be adjusted in real time based on the temperature model. In some embodiments, the temperature model can reflect the global or overall temperature distribution within the cavity. In some embodiments, the temperature model can reflect the temperature gradient within the cavity (e.g., axial temperature gradient, radial temperature gradient).

[0112] Example 1: LT crystal (LiTaO3) growth

[0113] Perform the installation steps for the crystal preparation apparatus.

[0114] Step 1: Adjust the levelness of the tray assembly. The levelness should be less than 0.1mm / m.

[0115] Step 2: Adjust the distance between the lower end surface of the cavity and the bottom plate to no less than 100 mm.

[0116] Step 3: Adjust the concentricity between the cavity and the lifting assembly to less than 3mm.

[0117] Step 4: The raw materials required to grow LT crystals are loaded into the cavity.

[0118] Step 5: Install the insulation cylinder and upper sealing cover.

[0119] Step 6: Install the furnace cover.

[0120] Step 7: Install the laser emitters on the furnace cover. Install the laser shaping collimator lens on the upper surface of the laser input window and confirm the laser aperture size and relative position. A total of six laser emitters and six corresponding laser shaping collimators are installed. Three laser emitters form a ring, for a total of two rings. The spacing between adjacent rings is 50 mm. The radius of the innermost ring is 220 mm, and the radius of the outermost ring is 270 mm.

[0121] Step 8: Install the lifting assembly.

[0122] The reactants required for growing LT crystals include Ta2O5 and Li2CO3. Each reactant has a purity greater than or equal to 99.999% and is obtained by calcining at 800°C for 5 hours and then cooling to room temperature. The molar ratio of the reactants is calculated according to the following reaction equation: Ta2O5 + Li2CO3 = 2LiTaO3 + CO2↑, where the excess Li2CO3 is 0.001% to 10% of its theoretical weight (i.e., the theoretical weight calculated based on the reaction equation).

[0123] After weighing, all reaction materials are placed in a three-dimensional mixer and mixed for 0.5-48 hours. After removal, they are placed in a pressing mold and pressed into cylindrical blocks using a cold isostatic press at 100-300 MPa. The blocks are placed in a ceramic crucible with a diameter of 280 mm and an inner height of 120 mm, which is then placed in an insulation cylinder.

[0124] Adjust the concentricity of the ceramic crucible and the insulation tube, and align the upper end of the ceramic crucible with the lower end of the central insulation component. Sequentially adjust the concentricity of the ceramic crucible, upper sealing cover, and weighing component, ensuring a seal between the upper sealing cover and the insulation tube. Furthermore, assemble the observation unit and laser shaping collimator.

[0125] Flowing protective gas N2 or a mixed gas of N2 and O2 and cooling water are introduced, wherein the oxygen content accounts for 0.1%-10% of the volume of the flowing gas, and the flowing gas flow rate is in the range of 3mL / min-30L / min.

[0126] Set the parameters for growing crystals: crystal diameter to 157 mm, shoulder length to 30-45 mm, equal diameter length to 60 mm, tail length to 20-40 mm, heating time to 3 h-24 h, rotation speed to 2 rpm-10 rpm, pulling speed to 1-4 mm / h, cooling time to 3-60 h, and PID value to 0.5.

[0127] Install the LT seed crystal on the pulling assembly, connect the pulling assembly to the weighing component, and adjust the concentricity of the seed crystal and the upper sealing cover. Slowly lower the seed crystal to preheat during the heating process to avoid cracking of the seed crystal, and always keep the seed crystal 5-15mm away from the melt surface. Insert the material transfer component from the side of the observation part, and tightly connect the material transfer component to the discharge port of the mixing component. Prepare the mixing component for replenishment. When the raw material is partially melted, slowly sink the seed crystal to contact the melt, and adjust the temperature. During the temperature adjustment process, sink the seed crystal 2mm to fully melt the seed crystal and the melt, and the interface is intact, so as to reduce the cracking of the crystal caused by the seeding during the later cooling process of the crystal. After the temperature is appropriate, start the automatic control program to enter the automatic growth mode.

[0128] During the automatic growth mode, the temperature measurement component obtains temperature information related to the raw material or the cavity. Based on the obtained temperature information related to the raw material or the cavity, the control component outputs a control signal to control at least one of the operating power of the laser heating component, the shape of the laser beam, or the size of the laser beam, so that the temperature gradient (first temperature gradient) during crystal growth is consistent or substantially consistent with the preset temperature gradient, thereby achieving real-time adjustment of the temperature gradient during crystal growth. For example, when the first temperature gradient is lower than the preset temperature gradient, the control component controls to increase the operating power of the laser emitting unit corresponding to the outer sub-annular region, and / or decrease the operating power of the laser emitting unit corresponding to the inner sub-annular region, and / or adjust the laser shaping collimator corresponding to the outer sub-annular region to reduce the size of the corresponding laser beam or at least partially overlap adjacent laser beams, and / or adjust the laser shaping collimator corresponding to the inner sub-annular region to increase the size of the corresponding laser beam or reduce the overlap between adjacent laser beams, so as to increase the first temperature gradient and make the first temperature gradient consistent or substantially consistent with the preset temperature gradient. For another example, when the first temperature gradient is higher than the preset temperature gradient, the control component controls to reduce the operating power of the laser emitting unit corresponding to the outer sub-annular area, and / or increase the operating power of the laser emitting unit corresponding to the inner sub-annular area, and / or adjust the laser shaping collimator corresponding to the outer sub-annular area to increase the size of the corresponding laser beam or reduce the overlapping part between adjacent laser beams, and / or adjust the laser shaping collimator corresponding to the inner sub-annular area to reduce the size of the corresponding laser beam or at least partially overlap between adjacent laser beams, so as to reduce the first temperature gradient and make the first temperature gradient consistent with or basically consistent with the preset temperature gradient.

[0129] After the process of necking, shoulder release, automatic feeding, equalizing diameter, finishing, cooling, and increasing the oxygen ratio, the crystal growth is completed after 3-5 days.

[0130] like Figure 7 As shown, the color of the grown crystal is light yellow, and the shape of the crystal is consistent with the set shape. After testing, the crystal diameter is 157mm, the equal diameter length is 60mm, the surface is smooth, and there are no scattered points or inclusions inside the crystal.

[0131] Example 2: Ce:LYSO crystal growth

[0132] Perform the installation steps for the crystal preparation apparatus.

[0133] Step 1: Adjust the levelness of the tray assembly. The levelness should be less than 0.1mm / m.

[0134] Step 2: Adjust the distance between the lower end surface of the cavity and the bottom plate to no less than 100 mm.

[0135] Step 3: Adjust the concentricity between the cavity and the lifting assembly to less than 3mm.

[0136] Step 4: The raw materials required to grow Ce:LYSO crystals are loaded into the cavity.

[0137] Step 5: Install the insulation cylinder and upper sealing cover.

[0138] Step 6: Install the furnace cover.

[0139] Step 7: Install the laser emitters on the furnace cover. Install the laser shaping collimator lens on the upper surface of the laser input window and confirm the laser aperture size and relative position. Install a total of six laser emitters and six corresponding laser shaping collimators. The six laser emitters form a ring with a radius of 160mm-180mm.

[0140] Step 8: Install the lifting assembly.

[0141] The reactants required to grow Ce:LYSO crystals include lutetium oxide, yttrium oxide, silicon oxide, and cerium oxide. Each reactant has a purity greater than or equal to 99.999%. All reactants are calcined at 1200°C for 5 hours and then cooled to room temperature. The molar ratio of each reactant is calculated according to the following reaction equation:

[0142] (1-xy)Lu2O3+yY2O3+SiO2+2xCeO2→Lu 2(1-x-y) Y 2y Ce 2x SiO5+x / 2O2↑

[0143] Wherein, x=0.10%, y=5%-35%, SiO2 is in excess of 0.1%-5% of its theoretical weight, and other raw materials are weighed according to the stoichiometric ratio in the chemical equation.

[0144] After weighing, all reaction materials are placed in a three-dimensional mixer and mixed for 0.5-48 hours. After removal, they are placed in a pressing mold and pressed into cylindrical blocks using a cold isostatic press at 100-300 MPa. The blocks are placed in an iridium crucible with a diameter of 220 mm and an inner height of 120 mm, which is then placed in a heat-insulating cylinder.

[0145] Adjust the concentricity of the iridium crucible and the insulation cylinder, and align the upper end of the crucible with the lower end of the central insulation component. Sequentially adjust the concentricity of the crucible, upper sealing cover, and weighing component, ensuring a seal between the upper sealing cover and the insulation cylinder. Furthermore, assemble the observation unit and laser shaping collimator.

[0146] Flowing protective gas N2, or a mixed gas of N2 and O2 and cooling water are introduced, wherein the oxygen content accounts for 0.1%-10% of the volume of the flowing gas, and the flowing gas flow rate is in the range of 3mL / min-30L / min.

[0147] Set the following parameters for growing the crystal: crystal diameter to 75 mm, shoulder length to 15-35 mm, equal diameter length to 189 mm, tail length to 20-40 mm, heating time to 3-24 h, rotation speed to 2-10 rpm, pulling speed to 1-4 mm / h, cooling time to 3-60 h, and PID value to 0.02.

[0148] Install the Ce:LYSO seed crystal on the pulling assembly, which is connected to the weighing component, and adjust the concentricity of the seed crystal and the upper sealing cover. Slowly lower the seed crystal during the heating process to preheat it to avoid cracking of the seed crystal, and always keep the seed crystal 5-15mm away from the melt surface. Insert the material transfer component from the side of the observation part, and tightly connect the material transfer component to the discharge port of the mixing component. Prepare the mixing component for replenishment. When the raw material is partially melted, slowly sink the seed crystal to contact the melt, and adjust the temperature. During the temperature adjustment process, sink the seed crystal 2mm to fully melt the seed crystal and the melt, and the interface is intact, thereby reducing the cracking of the crystal caused by the seeding during the later cooling process of the crystal. After the temperature is appropriate, start the automatic control program to enter the automatic growth mode.

[0149] During the automatic growth mode, the temperature measurement component obtains temperature information related to the raw material or the cavity. Based on the obtained temperature information related to the raw material or the cavity, the control component outputs a control signal to control at least one of the operating power of the laser heating component, the shape of the laser beam, or the size of the laser beam, so that the temperature gradient (first temperature gradient) during crystal growth is consistent or substantially consistent with the preset temperature gradient, thereby achieving real-time adjustment of the temperature gradient during crystal growth. For example, when the first temperature gradient is lower than the preset temperature gradient, the control component controls to increase the operating power of the laser emitting unit corresponding to the outer sub-annular region, and / or decrease the operating power of the laser emitting unit corresponding to the inner sub-annular region, and / or adjust the laser shaping collimator corresponding to the outer sub-annular region to reduce the size of the corresponding laser beam or at least partially overlap adjacent laser beams, and / or adjust the laser shaping collimator corresponding to the inner sub-annular region to increase the size of the corresponding laser beam or reduce the overlap between adjacent laser beams, so as to increase the first temperature gradient and make the first temperature gradient consistent or substantially consistent with the preset temperature gradient. For another example, when the first temperature gradient is higher than the preset temperature gradient, the control component controls to reduce the operating power of the laser emitting unit corresponding to the outer sub-annular area, and / or increase the operating power of the laser emitting unit corresponding to the inner sub-annular area, and / or adjust the laser shaping collimator corresponding to the outer sub-annular area to increase the size of the corresponding laser beam or reduce the overlapping part between adjacent laser beams, and / or adjust the laser shaping collimator corresponding to the inner sub-annular area to reduce the size of the corresponding laser beam or at least partially overlap between adjacent laser beams, so as to reduce the first temperature gradient and make the first temperature gradient consistent with or basically consistent with the preset temperature gradient.

[0150] After 10-15 days of process flow including necking, shoulder release, automatic feeding, equalizing diameter, finishing, cooling, and increasing oxygen ratio, crystal growth is completed.

[0151] like Figure 8A and Figure 8B As shown, the grown crystals are colorless and transparent, and the crystal shape is consistent with the set shape. After testing, the crystal diameter is 75mm, the equal diameter length is 189mm-199mm, there are slight back-melt strips on the surface, and there are no scattered points or inclusions inside the crystal.

[0152] The beneficial effects that may be brought about by the embodiments of this specification include but are not limited to: (1) using a laser heating component to heat the raw material can make the raw material from the annular heating zone to the center of the cavity melt to form a raw material melt to grow crystals, while the raw material away from the center of the cavity (i.e., near the side wall of the cavity) does not melt, which not only improves the heat utilization rate, but also prevents the cavity from volatilizing due to excessive temperature and contaminating the raw material; (2) using a laser heating component to heat the raw material can make the material of the cavity not limited to metal materials such as copper, iron, and stainless steel, which can reduce the cost of the cavity and further reduce the preparation cost of the crystal; (3) the cavity includes a cooling structure for passing a cooling medium to reduce the temperature of the cavity, which can prevent the cavity from volatilizing due to excessive temperature and contaminating the raw material, and further ensure the quality of the grown crystal; (4) during the crystal growth process, the temperature gradient of the crystal growth can be adjusted in real time by adjusting the heating parameters of the laser heating component to facilitate the automatic growth of the crystal; (5) during the crystal growth process, based on the temperature information related to the raw material or the cavity, the heating parameters of the laser heating component can be adjusted in real time to facilitate the automatic growth of the crystal. It should be noted that different embodiments may produce different beneficial effects. In different embodiments, the beneficial effects that may be produced may be any one or a combination of the above, or any other possible beneficial effects.

[0153] While the basic concepts have been described above, it will be apparent to those skilled in the art that the detailed disclosure is merely illustrative and does not limit this specification. Although not explicitly stated herein, various modifications, improvements, and revisions to this specification may be made by those skilled in the art. Such modifications, improvements, and revisions are suggested in this specification and remain within the spirit and scope of the exemplary embodiments of this specification.

[0154] This specification also uses specific terms to describe the embodiments of this specification. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a feature, structure, or characteristic associated with at least one embodiment of this specification. Therefore, it should be emphasized and noted that references to "one embodiment," "an embodiment," or "an alternative embodiment" two or more times in different locations in this specification do not necessarily refer to the same embodiment. Furthermore, certain features, structures, or characteristics of one or more embodiments of this specification may be appropriately combined.

[0155] Similarly, it should be noted that, in order to simplify the presentation of this specification and thus facilitate understanding of one or more embodiments of the invention, the foregoing descriptions of the embodiments of this specification sometimes combine multiple features into a single embodiment, figure, or description thereof. However, this disclosure method does not imply that the subject matter of this specification requires more features than those recited in the claims. In fact, an embodiment may have fewer features than all of the features of a single disclosed embodiment.

[0156] In some embodiments, numbers are used to describe the quantity of components and attributes. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise stated, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the description and claims are approximate values, which may change according to the required characteristics of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of this specification are approximate values, in specific embodiments, the settings of such numerical values ​​are as accurate as possible within the feasible range.

[0157] Each patent, patent application, patent application publication, and other materials, such as articles, books, specifications, publications, and documents, cited in this specification is hereby incorporated by reference in its entirety. This includes application history documents that are inconsistent with or conflict with the content of this specification, as well as documents (currently or subsequently attached to this specification) that limit the broadest scope of the claims of this specification. It should be noted that if the descriptions, definitions, and / or terminology used in the accompanying materials are inconsistent or conflicting with the content of this specification, the descriptions, definitions, and / or terminology used in this specification will control.

[0158] Finally, it should be understood that the embodiments described in this specification are intended only to illustrate the principles of the embodiments of this specification. Other variations may also fall within the scope of this specification. Therefore, by way of example and not limitation, alternative configurations of the embodiments of this specification may be considered consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly described and illustrated in this specification.

Claims

1. A crystal preparation device, characterized in that: The device comprises: A cavity is used to place raw materials; the cavity includes a cooling structure, which includes an inlet, an outlet, and a cooling channel; a cooling medium enters the cooling channel from the inlet and flows out from the outlet to reduce the temperature of the cavity portion close to the raw materials; the cavity includes an inner cavity and an outer cavity, and the inner cavity and the outer cavity are surrounded to form the cooling structure; a laser heating assembly for heating the raw material; the laser heating assembly comprises at least two laser emitting units mounted on a furnace cover above the cavity; the furnace cover is provided with a first through hole, and the at least two laser emitting units are circumferentially distributed on the furnace cover with the first through hole as the center, forming at least two annular shapes; the difference between the radius of the outermost annular shape and the radius of the cavity is within a range of 50 mm to 500 mm; a liquid level sensor, configured to measure liquid level position information of the melt in the cavity and transmit the liquid level position information to a control component; A moving component, used for driving the cavity to move; a pulling assembly for up and down movement and / or rotation for crystal growth; and The control component is used to adjust the heating parameters of the laser heating component in real time during the crystal growth process to adjust the temperature gradient during the crystal growth process in real time, and is used to control the movement of the moving component based on the liquid level position information during the crystal growth process to control the movement of the cavity and maintain a constant distance between the at least two laser emitting units and the melt liquid surface.

2. The crystal preparation device according to claim 1, characterized in that The radius of the innermost annular shape is in the range of 25 mm to 300 mm.

3. The crystal preparation device according to claim 1, characterized in that The spacing between adjacent annular shapes is in the range of 5 mm to 200 mm.

4. The crystal preparation device according to claim 1, characterized in that The heating parameters of the laser heating assembly include at least one of operating power, a shape of the laser beam, or a size of the laser beam.

5. The crystal preparation device according to claim 1, characterized in that: The crystal preparation device further includes a temperature measuring component for measuring temperature information related to the raw material or the cavity. The control component also adjusts the heating parameters of the laser heating component in real time based on the temperature information.

6. The crystal preparation apparatus according to claim 5, wherein: The temperature gradient includes a radial temperature gradient, and the radial temperature gradient includes a first temperature gradient and a second temperature gradient, wherein, The first temperature gradient refers to the temperature gradient from the annular heating zone formed by the laser heating assembly to the center point of crystal growth, and the first temperature gradient is a negative temperature gradient; The second temperature gradient refers to the temperature gradient from the annular heating zone to the inner wall of the cavity, and the second temperature gradient is a negative temperature gradient.

7. The crystal preparation device according to claim 5, characterized in that: The control component also performs simulation modeling based on the temperature information and adjusts the heating parameters of the laser heating component in real time based on the simulation results.

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