BBO crystal growth device and growth method

Abstract

The invention discloses a BBO crystal growth device and a growth method, and relates to the technical field of crystal material growth. The growth method comprises the following steps: mixing and heating barium carbonate, boric acid, sodium carbonate and sodium fluoride to obtain a mixed solution, and putting the mixed solution into a crucible; arranging a seed crystal rod in the crucible, binding a BBO seed crystal on the seed crystal rod, enabling the end part of the BBO seed crystal to be in contact with the liquid level of the mixed solution, and driving the seed crystal rod to rotate at a preset speed; the temperature in the growth furnace is kept at a first preset temperature within a first preset time range; the temperature in the growth furnace is reduced at a first cooling rate within a second preset time range; the temperature in the growth furnace is reduced at a second cooling rate within a third preset time range; the temperature in the growth furnace is reduced at a third cooling rate within a fourth preset time range; lifting the seed crystal rod after a fourth preset time range, enabling the BBO crystal to leave the mixed solution, and annealing the BBO crystal. The method ensures stable growth of the crystal, and improves the growth yield and optical performance of the crystal.

Description

Technical Field

[0001] The present invention relates to the technical field of crystal material growth, and in particular to a BBO crystal growth device and a growth method. Background Art

[0002] Low-temperature phase barium metaborate crystal (β-BaBO crystal, abbreviated as BBO crystal) has extremely wide light transmittance range, large phase matching angle, high light damage threshold, broadband temperature matching and excellent optical uniformity, and has advantages in the preparation of lasers and other fields.

[0003] Traditional BBO crystal growth often uses the top seeding method, using sodium oxide or sodium fluoride as the flux. When sodium oxide is used as the flux, the three-dimensional network of boron-oxygen polyhedra in the solution leads to high viscosity, hindering solute transport. Crystals are prone to defects such as inclusions and growth lines, resulting in low crystallization yields, small blanks, and low utilization rates. While using sodium fluoride as a flux can increase crystallization yields, reduce viscosity, facilitate solute transport, and reduce defects, its high volatility can cause deviations in solution composition and lead to unstable growth. Summary of the Invention

[0004] The object of the present invention is to provide a BBO crystal growth method, which can ensure the stable growth of BBO crystals and improve the yield and optical properties of the grown BBO crystals.

[0005] The embodiment of the present invention is achieved as follows:

[0006] In one aspect of the present invention, a BBO crystal growth method is provided, comprising: thoroughly mixing barium carbonate, boric acid, sodium carbonate, and sodium fluoride and heating and melting them to obtain a mixed solution; placing the mixed solution in a crucible, and placing the crucible in a growth furnace having a first preset temperature; arranging a seed crystal rod in the middle of the crucible, and tying a BBO seed crystal to the end of the seed crystal rod so that the end of the BBO seed crystal contacts the liquid surface of the mixed solution, and simultaneously driving the seed crystal rod to rotate the BBO seed crystal at a preset speed; maintaining the temperature in the growth furnace at the first preset temperature within a first preset time range of contact between the BBO seed crystal and the mixed solution; and maintaining the temperature at the first preset temperature within a second preset time range of contact between the BBO seed crystal and the mixed solution. time range, the temperature in the growth furnace decreases at a first cooling rate; within a third preset time range in which the BBO seed crystal is in contact with the mixed solution, the temperature in the growth furnace decreases at a second cooling rate, which is greater than the first cooling rate; within a fourth preset time range in which the BBO seed crystal is in contact with the mixed solution, the temperature in the growth furnace decreases at a third cooling rate, which is greater than the first cooling rate and less than the second cooling rate; after the fourth preset time range in which the BBO seed crystal is in contact with the mixed solution, the seed crystal rod is lifted to allow the BBO crystal grown from the BBO seed crystal to leave the mixed solution, and the BBO crystal is annealed to room temperature at a preset rate.

[0007] Optionally, after placing the mixed solution in the crucible, the method further includes: raising the temperature in the growth furnace to 1000° C. within 6 hours and keeping it at that temperature for 2 days; and lowering the temperature in the growth furnace from 1000° C. to 915° C. within 6 hours.

[0008] Optionally, a seed crystal rod is provided in the middle of the crucible, and a BBO seed crystal is tied to the end of the seed crystal rod so that the end of the BBO seed crystal contacts the liquid surface of the mixed solution, and the seed crystal rod is driven to drive the BBO seed crystal to rotate at a preset speed, including: driving the seed crystal rod to drive the BBO seed crystal to rotate at a speed of 9 revolutions per minute.

[0009] Optionally, the temperature in the growth furnace is maintained at a first preset temperature within a first preset time range when the BBO seed crystal contacts the mixed solution, including: the temperature in the growth furnace is maintained at 915° C. within a time range of 0 to 2 days when the BBO seed crystal contacts the mixed solution.

[0010] Optionally, within a second preset time range in which the BBO seed crystal is in contact with the mixed solution, the temperature in the growth furnace is reduced at a first cooling rate, including: within a time range in which the BBO seed crystal is in contact with the mixed solution from 2 days to 2 months, the temperature in the growth furnace is reduced at 0.1°C / day.

[0011] Optionally, within a third preset time range in which the BBO seed crystal is in contact with the mixed solution, the temperature in the growth furnace is reduced at a second cooling rate, where the second cooling rate is greater than the first cooling rate, including: within a time range in which the BBO seed crystal is in contact with the mixed solution for 2 months to 5 months, the temperature in the growth furnace is reduced at 1.5°C / day.

[0012] Optionally, within a fourth preset time range in which the BBO seed crystal is in contact with the mixed solution, the temperature in the growth furnace is reduced at a third cooling rate, where the third cooling rate is greater than the first cooling rate and less than the second cooling rate, including: within a time range in which the BBO seed crystal is in contact with the mixed solution for 5 months to 7 months, the temperature in the growth furnace is reduced at 0.6°C / day.

[0013] Optionally, within a second preset time range in which the BBO seed crystal is in contact with the mixed solution, the temperature in the growth furnace is reduced at a first cooling rate, including: within a time range in which the BBO seed crystal is in contact with the mixed solution from 2 days to 1 month, the temperature in the growth furnace is reduced at 0.2°C / day.

[0014] Optionally, within a third preset time range in which the BBO seed crystal is in contact with the mixed solution, the temperature in the growth furnace is reduced at a second cooling rate, where the second cooling rate is greater than the first cooling rate, including: within a time range in which the BBO seed crystal is in contact with the mixed solution for 1 month to 3 months, the temperature in the growth furnace is reduced at 2°C / day.

[0015] Optionally, within a fourth preset time range in which the BBO seed crystal is in contact with the mixed solution, the temperature in the growth furnace is reduced at a third cooling rate, where the third cooling rate is greater than the first cooling rate and less than the second cooling rate, including: within a time range in which the BBO seed crystal is in contact with the mixed solution for 3 months to 5 months, the temperature in the growth furnace is reduced at 0.6°C / day.

[0016] Optionally, a seed crystal rod is provided in the middle of the crucible, and a BBO seed crystal is tied to the end of the seed crystal rod so that the end face of the BBO seed crystal contacts the liquid surface of the mixed solution, and the seed crystal rod is driven to rotate the BBO seed crystal at a preset speed. The method further includes: stirring the mixed solution within a first preset time range, a second preset time range, a third preset time range, and a fourth preset time range during which the BBO seed crystal contacts the mixed solution.

[0017] Another aspect of the present invention provides a BBO crystal growth device, which is applied to the BBO crystal growth method, including a growth furnace and a crucible arranged in the growth furnace, the crucible being used to place a solution; further comprising a seed rod and a stirring part, the seed rod being arranged in the middle of the crucible and being used to bind the BBO seed crystal; the stirring part comprising a stirring blade and a stirring rod, the stirring blade being arranged at the end of the stirring rod, and the end of the stirring rod away from the stirring blade being fixedly connected to the seed rod; the seed rod can drive the stirring part to rotate in the solution in the crucible with the seed rod as the rotation center.

[0018] Optionally, there are two stirring parts, which are respectively arranged on opposite sides of the seed crystal rod; the stirring rod has a bent portion so that the stirring blades are located on opposite sides of the BBO seed crystal.

[0019] Optionally, the stirring rod has three bent portions, so that the stirring blade is located at the bottom of the crucible and is arranged opposite to the BBO seed crystal.

[0020] The beneficial effects of the present invention include at least one of the following:

[0021] The present invention provides a BBO crystal growth method, comprising: fully mixing barium carbonate, boric acid, sodium carbonate and sodium fluoride and heating and melting them to obtain a mixed solution; during the heating process, the sodium carbonate can be decomposed to generate sodium oxide, which is combined with the sodium fluoride as a co-solvent; on the one hand, because fluoride ions can effectively destroy the network structure in the solution, the viscosity of the solution is greatly reduced, thereby improving solute transport and reducing the possibility of wrapping and growth lines appearing in the BBO crystal during the growth process; on the other hand, compared with sodium fluoride, sodium oxide is not easy to volatilize, ensuring the stability of the component ratio, thereby ensuring the stability of the solution; placing the mixed solution in a crucible, and placing the crucible in a growth furnace with a first preset temperature; arranging a seed crystal rod in the middle of the crucible, and tying a BBO seed crystal to the end of the seed crystal rod so that the end of the BBO seed crystal contacts the liquid surface of the mixed solution, and driving the seed crystal rod to drive the BBO seed crystal to rotate at a preset speed; During a first preset time range during which the BBO seed crystal is in contact with the mixed solution, the temperature in the growth furnace is maintained at a first preset temperature; during a second preset time range during which the BBO seed crystal is in contact with the mixed solution, the temperature in the growth furnace is reduced at a first cooling rate; during a third preset time range during which the BBO seed crystal is in contact with the mixed solution, the temperature in the growth furnace is reduced at a second cooling rate, which is greater than the first cooling rate; and during a fourth preset time range during which the BBO seed crystal is in contact with the mixed solution, the temperature in the growth furnace is reduced at a third cooling rate, which is greater than the first cooling rate but less than the second cooling rate. By adaptively adjusting the temperature at different stages of crystal growth, the crystal growth yield can be further improved in conjunction with the solution. After the fourth preset time range during which the BBO seed crystal is in contact with the mixed solution, the seed rod is lifted to remove the BBO crystal grown from the BBO seed crystal from the mixed solution, and the BBO crystal is annealed to room temperature at a preset rate. The above-described BBO crystal growth method can ensure stable growth of the BBO crystal and improve the yield and optical properties of the BBO crystal.

[0022] The present invention also provides a BBO crystal growth device for use in a BBO crystal growth method, comprising a growth furnace and a crucible disposed within the growth furnace for holding a solution; a seed rod disposed in the middle of the crucible for holding a BBO seed crystal; and a stirring portion comprising a stirring blade and a stirring rod, the stirring blade disposed at the end of the stirring rod, the end of the stirring rod remote from the stirring blade being fixedly connected to the seed rod. The seed rod drives the stirring portion to rotate within the solution in the crucible, with the seed rod as the center of rotation. The BBO crystal growth device, through the provision of the stirring portion, ensures sufficient convection of the solution during crystal growth, significantly suppressing the formation of crystal defects. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 A schematic flow chart of a BBO crystal growth method is provided for an embodiment of the present invention;

[0025] Figure 2 One of the structural schematic diagrams of a BBO crystal growth device is provided for an embodiment of the present invention;

[0026] Figure 3 The second structural diagram of the BBO crystal growth device is provided for the embodiment of the present invention.

[0027] Icon: 100-BBO crystal growth device; 110-crucible; 120-seed crystal rod; 130-stirring part; 131-stirring rod; 132-stirring blade; 200-mixed solution; 300-BBO crystal. DETAILED DESCRIPTION

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0030] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0031] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" and the like indicate positions or locations based on the positions shown in the accompanying drawings, or the positions or locations in which the inventive product is typically placed when in use. These terms are intended solely to facilitate the description of the present invention and to simplify the description, and are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third," etc., are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0032] In addition, the terms "horizontal" and "vertical" do not mean that the components must be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", not that the structure must be completely horizontal, but can be slightly tilted.

[0033] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0034] Please refer to Figure 1 This embodiment provides a BBO crystal growth method, comprising the following steps:

[0035] Step S100, fully mixing barium carbonate, boric acid, sodium carbonate and sodium fluoride and heating and melting them to obtain a mixed solution 200;

[0036] Specifically, the growth method first selects high-purity barium carbonate (BaCO), boric acid (HBO), sodium carbonate (NaCO), and sodium fluoride (NaF) as starting materials. Barium carbonate, as a provider of barium, is an important source of barium ions in the BBO crystal structure; boric acid contributes boron to the crystal, playing a key role in building the basic skeleton of the BBO crystal; sodium carbonate can decompose to form sodium oxide, which is combined with sodium fluoride as a co-solvent. On the one hand, because fluoride ions can effectively destroy the network structure in the solution, the viscosity of the solution is greatly reduced, thereby improving solute transport and reducing the possibility of wrapping and growth lines in the BBO crystal during growth. On the other hand, compared with sodium fluoride, sodium oxide is less volatile, ensuring the stability of the component ratio and thus the stability of the solution. Therefore, compared with the existing growth methods that use sodium oxide or sodium fluoride as solvents, the solution prepared by the present application using the above raw materials has a lower viscosity, thereby reducing the possibility of defects during the growth of BBO crystal 300.

[0037] After the above raw materials are fully mixed, they are placed in a muffle furnace and heated to 1000° C. Through multiple melting processes, the above raw materials are completely melted into a mixed solution 200 to provide a growth environment for the subsequent growth of BBO crystals 300.

[0038] Step S200: placing the mixed solution 200 in the crucible 110, and placing the crucible 110 in a growth furnace with a first preset temperature;

[0039] Specifically, after obtaining a uniform mixed solution 200 in step S100, the mixed solution 200 is transferred to a high-temperature resistant crucible 110. Preferably, the crucible 110 is made of platinum. The platinum crucible 110 can withstand various chemical substances in the mixed solution 200, so that the grown BBO crystals will not have defects or performance degradation due to interference from the crucible 110 material. At the same time, its thermal conductivity is relatively high, which can evenly distribute heat in the crucible 110. When the mixed solution 200 is heated, the heat can be quickly and evenly transferred to all parts of the solution, so that the components in the solution can be melted synchronously.

[0040] Next, the crucible 110 containing the mixed solution 200 is stably placed in the growth furnace. At this time, the growth furnace is accurately set to a first preset temperature, thereby forming an environment conducive to crystal formation.

[0041] It should be noted that after the mixed solution 200 is placed in the crucible 110, the following steps may be performed to set the growth furnace at the first preset temperature:

[0042] First, the temperature in the growth furnace is raised to 1000°C within 6 hours and maintained at this temperature for 2 days. This prevents undesirable phenomena such as local overheating of the mixed solution 200 in the crucible 110, uneven boiling, or splashing of the solution due to excessive thermal stress caused by a rapid temperature rise. The relatively slow and steady temperature increase ensures that the mixed solution 200 in the crucible 110 is heated evenly, allowing the various components in the solution to smoothly enter a high-temperature initial state, laying a good thermal environment foundation for the subsequent crystal growth process. The insulation process allows the solution to achieve sufficient thermal and chemical equilibrium. Then, the temperature in the growth furnace is cooled from 1000°C to 915°C within 6 hours.

[0043] Step S300: a seed crystal rod 120 is disposed in the middle of the crucible 110, and a BBO seed crystal is attached to the end of the seed crystal rod 120 so that the end of the BBO seed crystal contacts the liquid surface of the mixed solution 200. The seed crystal rod 120 is driven to rotate the BBO seed crystal at a preset speed.

[0044] Specifically, a seed rod 120 is arranged in the middle of the crucible 110. The seed rod 120 is usually made of a material that is resistant to high temperatures and has good chemical stability. Preferably, the seed rod 120 is made of quartz, which can maintain structural stability in a high temperature environment and does not react with the surrounding chemicals, thereby ensuring that there will be no pollution to the crystal growth process.

[0045] Next, select a BBO seed crystal and securely attach it to the end of the seed rod 120. During the attachment process, ensure that the seed crystal is tightly connected to the seed rod 120 to prevent it from loosening or falling off during subsequent rotation. Before placing the BBO seed crystal in the solution, place it above the liquid surface and maintain a constant temperature for 20 minutes. Then, slowly lower the seed rod 120 so that the end of the BBO seed crystal contacts the liquid surface of the mixed solution 200. Once the BBO seed crystal contacts the mixed solution 200, the BBO seed crystal begins to grow.

[0046] At the same time, the driving device is started, so that the seed crystal rod 120 drives the BBO seed crystal to rotate at a preset speed, which can make the solute in the solution deposit evenly on the surface of the seed crystal, ensuring the orderly growth of the crystal along a specific lattice direction, and laying a solid foundation for ultimately obtaining high-quality BBO crystals with good optical properties and crystalline morphology.

[0047] It should be noted that, in one embodiment of the present application, the driving seed crystal rod 120 drives the BBO seed crystal to rotate at a speed of 9 revolutions per minute to promote uniform diffusion of the solute and reduce impurity inclusion.

[0048] Step S400: During a first preset time range in which the BBO seed crystal is in contact with the mixed solution 200, the temperature in the growth furnace is maintained at a first preset temperature;

[0049] Step S500: within a second preset time range in which the BBO seed crystal is in contact with the mixed solution 200, the temperature in the growth furnace is reduced at a first cooling rate;

[0050] Step S600: Within a third preset time range in which the BBO seed crystal is in contact with the mixed solution 200, the temperature in the growth furnace is reduced at a second cooling rate, where the second cooling rate is greater than the first cooling rate;

[0051] Step S700: During a fourth preset time period in which the BBO seed crystal is in contact with the mixed solution 200, the temperature in the growth furnace is reduced at a third cooling rate, where the third cooling rate is greater than the first cooling rate and less than the second cooling rate.

[0052] It should be noted that, in one embodiment of the present application, in the above steps S400 to S700, the mixed solution 200 can be stirred within the first preset time range, the second preset time range, the third preset time range, and the fourth preset time range of the contact between the BBO seed crystal and the mixed solution 200, so that the mixed solution 200 is always in a convection state, thereby further suppressing the formation of defects in the BBO crystal 300.

[0053] In existing growth methods, the cooling rate is usually a constant value, which cannot be coordinated with crystals at different growth stages. This can easily lead to problems such as disordered structure in the early stage of crystal growth, low growth efficiency in the middle stage, and defects in the late stage, affecting the crystal quality and growth effect. In the early stage of crystal growth, due to the relatively large degree of supercooling, the cooling rate during this period should not be too large; in the middle stage of crystal growth, the crystal grows relatively large and can receive more solute precipitation, so the cooling rate during this period can be appropriately increased; in the late stage of crystal growth, due to the relatively low growth temperature, the solution viscosity during this period is relatively high, so the cooling rate can be appropriately reduced. In the growth method of the present application, through the above-mentioned steps S400 to S700, different cooling rates can be adopted in different crystal growth stages, thereby improving the growth efficiency and yield of the BBO crystal 300.

[0054] Step S800: After the BBO seed crystal contacts the mixed solution 200 for a fourth preset time, the seed rod 120 is lifted to allow the BBO crystal 300 grown from the BBO seed crystal to leave the mixed solution 200, and the BBO crystal 300 is annealed to room temperature at a preset rate.

[0055] Specifically, after the above steps, the BBO seed crystal has gradually grown from the initial seed crystal form into a BBO crystal 300 with a certain size and structural integrity, such as Figure 2 、 Figure 3As shown, the grown BBO crystal is located in the mixed solution 200. Next, the seed rod 120 is lifted. As the seed rod 120 is slowly lifted, the BBO crystal grown from the BBO seed crystal gradually leaves the mixed solution 200.

[0056] To improve the quality and performance stability of the crystal, the BBO crystal is then annealed. During the annealing process, atoms or ions within the crystal begin to slowly diffuse and rearrange, releasing stress and repairing lattice defects to a certain extent. Impurity atoms may also migrate and accumulate at specific locations on the surface or within the crystal, significantly improving the overall quality of the crystal. Ultimately, a high-quality BBO crystal is obtained, meeting the application requirements of laser technology and other fields.

[0057] The above-mentioned BBO crystal growth method can ensure the stable growth of the BBO crystal 300 and improve the yield and optical performance of the grown BBO crystal 300 .

[0058] Another aspect of the present invention, as Figure 2 and Figure 3 As shown, a BBO crystal growth device 100 is provided, which is applied to a BBO crystal growth method, and includes a growth furnace and a crucible 110 disposed in the growth furnace, the crucible 110 being used to place a solution; the device also includes a seed rod 120 and a stirring portion 130, the seed rod 120 being disposed in the middle of the crucible 110 and being used to bind a BBO seed crystal; the stirring portion 130 includes a stirring blade 132 and a stirring rod 131, the stirring blade 132 being disposed at the end of the stirring rod 131, and the end of the stirring rod 131 away from the stirring blade 132 being fixedly connected to the seed rod 120; the seed rod 120 can drive the stirring portion 130 to rotate in the solution in the crucible 110 with the seed rod 120 as the rotation center.

[0059] Specifically, the growth furnace, the core heating component of the entire device, possesses precise temperature control capabilities. It accurately raises, maintains, or lowers the furnace temperature according to the requirements of different stages of the BBO crystal growth process, creating a stable and suitable thermal environment for crystal growth. The seed rod 120, positioned in the center of the crucible 110, ensures that the BBO seed crystals attached to its ends are in a relatively balanced growth environment, reducing crystal growth unevenness caused by edge effects or local environmental differences.

[0060] The stirring portion 130 includes a stirring blade 132 and a stirring rod 131 . The stirring blade 132 is a component that directly contacts the solution and generates a stirring effect. Preferably, the stirring blade 132 is made of a material that is corrosion-resistant, high-temperature-resistant, and has a certain mechanical strength.

[0061] When the seed crystal rod 120 starts to rotate under the action of the external drive device, since the stirring part 130 is fixedly connected to the seed crystal rod 120, the stirring part 130 will also rotate synchronously with the seed crystal rod 120 as the rotation center. The rotation around the seed crystal rod 120 can ensure that the stirring action is closely carried out around the seed crystal, so that the solution around the seed crystal is stirred most fully and effectively. In this way, the solute in the solution can quickly diffuse to the surface of the seed crystal, providing sufficient material supply for crystal growth, and at the same time, it can also promptly remove the by-products or excess solutes generated by the reaction on the surface of the seed crystal, keeping the growth environment on the surface of the seed crystal stable and suitable. At the same time, the rotation method with the seed crystal rod 120 as the rotation center can ensure the stability and symmetry of the stirring process, reduce local fluctuations or temperature changes of the solution caused by uneven stirring, thereby providing a more stable, uniform and controllable environment for crystal growth, helping to improve the growth quality and efficiency of the crystal and reduce the probability of internal defects in the crystal.

[0062] The BBO crystal growth apparatus 100 can ensure that the solution is in a convection state during the crystal growth process by disposing the stirring portion 130 , thereby greatly suppressing the formation of crystal defects.

[0063] It should be noted that, in a specific embodiment of the present application, Figure 2 As shown, there are two stirring parts 130 , which are respectively disposed on opposite sides of the seed crystal rod 120 ; the stirring rod 131 has a bent portion so that the stirring blades 132 are located on opposite sides of the BBO seed crystal.

[0064] Specifically, if Figure 2 As shown, the stirring rod 131 has a bent portion to form an L-shaped structure. Optionally, the stirring blade 132 at its end is rectangular. There are two stirring sections 130, which are respectively arranged on opposite sides of the seed crystal rod 120 to ensure the solution around the seed crystal is stirred most fully and effectively.

[0065] In another specific embodiment of the present application, Figure 3 As shown, the stirring rod 131 has three bent portions, so that the stirring blade 132 is located at the bottom of the crucible 110 and is arranged opposite to the BBO seed crystal.

[0066] Specifically, if Figure 3 As shown, stirring rod 131 has three bends, allowing one end of stirring rod 131 to be fixedly connected to seed crystal rod 120 and bent to extend toward mixed solution 200. Once stirring rod 131 reaches the bottom of crucible 110, it bends again to form an L-shaped structure, positioned opposite the BBO seed crystal. Optionally, stirring blades 132 at the end of the stirring rod 131 may be configured as multiple fan-shaped blades, enabling sufficient and effective stirring of the solution surrounding the seed crystal.

[0067] In Example 1 of the present application, the BBO crystal growth method is as follows:

[0068] Weigh 3240.00 g of BaCO3, 2028.69 g of H3BO3, 517.45 g of Na2CO3, and 35.82 g of NaF, mix these materials thoroughly, and heat them to 1000°C in a muffle furnace until the materials are completely melted into a mixed solution of 200°C.

[0069] The mixed solution 200 is placed in a crucible 110, and the crucible 110 is placed in a growth furnace. The growth furnace is heated to 1000° C. within 6 hours and kept warm for 2 days, and then slowly cooled to 915° C. within 6 hours.

[0070] A BBO seed crystal was attached to the end of a seed rod 120 and slowly lowered above the surface of mixed solution 200. After maintaining the temperature for 20 minutes, the BBO seed crystal was moved below the surface of mixed solution 200 to ensure full contact with the solution. Simultaneously, the BBO seed crystal was rotated by seed rod 120 at a speed of 9 rpm. At this point, the BBO seed crystal began to grow.

[0071] During the time period from 0 to 2 days that the BBO seed crystals are in contact with the mixed solution 200 , the temperature in the growth furnace is maintained at 915° C.

[0072] During the period from 2 days to 2 months that the BBO seed crystals are in contact with the mixed solution 200 , the temperature in the growth furnace is decreased at a rate of 0.1° C. / day.

[0073] During the period from 2 months to 5 months that the BBO seed crystals were in contact with the mixed solution 200, the temperature in the growth furnace was decreased at a rate of 1.5° C. / day.

[0074] During the period of 5 to 7 months that the BBO seed crystals were in contact with the mixed solution 200, the temperature in the growth furnace was decreased at a rate of 0.6° C. / day.

[0075] After the BBO seed crystal is in contact with the mixed solution 200 for 5 to 7 months, the BBO seed crystal grows into a BBO crystal 300. The seed rod 120 is lifted to separate the BBO crystal 300 from the mixed solution 200 and annealed to room temperature within 60 hours.

[0076] In Example 2 of the present application, the BBO crystal growth method is as follows:

[0077] Weigh 3240.00 g of BaCO3, 2028.69 g of H3BO3, 517.45 g of Na2CO3, and 35.82 g of NaF, mix these materials thoroughly, and heat them to 1000°C in a muffle furnace until the materials are completely melted into a mixed solution of 200°C.

[0078] The mixed solution 200 is placed in a crucible 110, and the crucible 110 is placed in a growth furnace. The growth furnace is heated to 1000° C. within 6 hours and kept warm for 2 days, and then slowly cooled to 915° C. within 6 hours.

[0079] A BBO seed crystal was attached to the end of a seed rod 120 and slowly lowered above the surface of mixed solution 200. After maintaining the temperature for 20 minutes, the BBO seed crystal was moved below the surface of mixed solution 200 to ensure full contact with the solution. Simultaneously, the BBO seed crystal was rotated by seed rod 120 at a speed of 9 rpm. At this point, the BBO seed crystal began to grow.

[0080] During the time period from 0 to 2 days that the BBO seed crystals are in contact with the mixed solution 200 , the temperature in the growth furnace is maintained at 915° C., while the mixed solution 200 is stirred.

[0081] During the period from 2 days to 1 month that the BBO seed crystals are in contact with the mixed solution 200 , the temperature in the growth furnace is decreased by 0.2° C. / day while the mixed solution 200 is stirred.

[0082] During the period of 1 to 3 months that the BBO seed crystals were in contact with the mixed solution 200 , the temperature in the growth furnace was decreased by 2° C. / day while the mixed solution 200 was stirred.

[0083] During the period of 3 to 5 months that the BBO seed crystals were in contact with the mixed solution 200 , the temperature in the growth furnace was decreased at a rate of 0.6° C. / day while the mixed solution 200 was stirred.

[0084] After the BBO seed crystal is in contact with the mixed solution 200 for 3 to 5 months, the BBO seed crystal grows into a BBO crystal 300. The seed rod 120 is lifted to separate the BBO crystal 300 from the mixed solution 200 and annealed to room temperature within 60 hours.

[0085] In particular, the present application does not impose any limitation on the stirring form of the mixed solution 200. The number of stirring parts 130 of the BBO crystal growth device 100 can be two, and the two stirring parts 130 are respectively arranged on opposite sides of the seed rod 120; or, the number of the stirring part 130 can be one, and the stirring rod 131 of the stirring part 130 has three bending parts, so that the stirring blade 132 is located at the bottom of the crucible 110 and is arranged opposite to the BBO seed crystal.

[0086] In Example 3 of the present application, the BBO crystal growth method is as follows:

[0087] Weigh 3240.00 g of BaCO3, 2028.69 g of H3BO3, 517.45 g of Na2CO3, and 35.82 g of NaF, mix these materials thoroughly, and heat them to 1000°C in a muffle furnace until the materials are completely melted into a mixed solution of 200°C.

[0088] The mixed solution 200 is placed in a crucible 110, and the crucible 110 is placed in a growth furnace. The growth furnace is heated to 1000° C. within 6 hours and kept warm for 2 days, and then slowly cooled to 915° C. within 6 hours.

[0089] A BBO seed crystal was attached to the end of a seed rod 120 and slowly lowered above the surface of mixed solution 200. After maintaining the temperature for 20 minutes, the BBO seed crystal was moved below the surface of mixed solution 200 to ensure full contact with the solution. Simultaneously, the BBO seed crystal was rotated by seed rod 120 at a speed of 9 rpm. At this point, the BBO seed crystal began to grow.

[0090] During the time period from 0 to 2 days that the BBO seed crystals are in contact with the mixed solution 200 , the temperature in the growth furnace is maintained at 915° C., while the mixed solution 200 is stirred.

[0091] During the period from 2 days to 2 months that the BBO seed crystals are in contact with the mixed solution 200 , the temperature in the growth furnace is decreased by 0.1° C. / day while the mixed solution 200 is stirred.

[0092] During the period of 2 to 5 months that the BBO seed crystals were in contact with the mixed solution 200 , the temperature in the growth furnace was decreased by 1.5° C. / day while the mixed solution 200 was stirred.

[0093] During the period of 5 to 7 months that the BBO seed crystals were in contact with the mixed solution 200 , the temperature in the growth furnace was decreased at a rate of 0.6° C. / day while the mixed solution 200 was stirred.

[0094] After the BBO seed crystal is in contact with the mixed solution 200 for 5 to 7 months, the BBO seed crystal grows into a BBO crystal 300. The seed rod 120 is lifted to separate the BBO crystal 300 from the mixed solution 200 and annealed to room temperature within 60 hours.

[0095] In particular, the present application does not impose any limitation on the stirring form of the mixed solution 200. The number of stirring parts 130 of the BBO crystal growth device 100 can be two, and the two stirring parts 130 are respectively arranged on opposite sides of the seed rod 120; or, the number of the stirring part 130 can be one, and the stirring rod 131 of the stirring part 130 has three bending parts, so that the stirring blade 132 is located at the bottom of the crucible 110 and is arranged opposite to the BBO seed crystal.

[0096] The foregoing description is merely an optional embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

[0097] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A BBO crystal growth method, characterized in that: include: Barium carbonate, boric acid, sodium carbonate and sodium fluoride are fully mixed and heated to melt to obtain a mixed solution (200); Placing the mixed solution (200) in a crucible (110), and placing the crucible (110) in a growth furnace with a first preset temperature; A seed crystal rod (120) is arranged in the middle of the crucible (110), and a BBO seed crystal is tied to the end of the seed crystal rod (120), so that the end of the BBO seed crystal is in contact with the liquid surface of the mixed solution (200), and the seed crystal rod (120) is driven to drive the BBO seed crystal to rotate at a preset speed; During a first preset time range in which the BBO seed crystal is in contact with the mixed solution (200), the temperature in the growth furnace is maintained at a first preset temperature; Within a second preset time range in which the BBO seed crystal is in contact with the mixed solution (200), the temperature in the growth furnace is reduced at a first cooling rate; Within a third preset time range in which the BBO seed crystal is in contact with the mixed solution (200), the temperature in the growth furnace is reduced at a second cooling rate, wherein the second cooling rate is greater than the first cooling rate; Within a fourth preset time range in which the BBO seed crystal is in contact with the mixed solution (200), the temperature in the growth furnace is reduced at a third cooling rate, wherein the third cooling rate is greater than the first cooling rate and less than the second cooling rate; After the BBO seed crystal is in contact with the mixed solution (200) for a fourth preset time range, the seed crystal rod (120) is lifted to allow a BBO crystal (300) grown from the BBO seed crystal to leave the mixed solution (200), and the BBO crystal (300) is annealed to room temperature at a preset rate.

2. The BBO crystal growth method according to claim 1, characterized in that: After placing the mixed solution (200) in the crucible (110), the method further comprises: Raising the temperature in the growth furnace to 1000° C. within 6 hours and maintaining the temperature for 2 days; The temperature in the growth furnace was lowered from 1000° C. to 915° C. within 6 hours.

3. The BBO crystal growth method according to claim 1, characterized in that: A seed crystal rod (120) is arranged in the middle of the crucible (110), and a BBO seed crystal is tied to the end of the seed crystal rod (120), so that the end of the BBO seed crystal is in contact with the liquid surface of the mixed solution (200), and the seed crystal rod (120) is driven to drive the BBO seed crystal to rotate at a preset speed, comprising: The seed crystal rod (120) is driven to drive the BBO seed crystal to rotate at a speed of 9 revolutions per minute.

4. The BBO crystal growth method according to claim 2, characterized in that: The temperature in the growth furnace is maintained at a first preset temperature within a first preset time range in which the BBO seed crystal is in contact with the mixed solution (200), comprising: During the time period of the BBO seed crystal being in contact with the mixed solution (200) ranging from 0 to 2 days, the temperature in the growth furnace is maintained at 915°C.

5. The BBO crystal growth method according to claim 4, characterized in that: Within a second preset time range in which the BBO seed crystal is in contact with the mixed solution (200), the temperature in the growth furnace is reduced at a first cooling rate, comprising: During the time period from 2 days to 2 months when the BBO seed crystal is in contact with the mixed solution (200), the temperature in the growth furnace is reduced by 0.1°C / day.

6. The BBO crystal growth method according to claim 5, characterized in that: Within a third preset time range in which the BBO seed crystal is in contact with the mixed solution (200), the temperature in the growth furnace is reduced at a second cooling rate, wherein the second cooling rate is greater than the first cooling rate, comprising: During the period of time that the BBO seed crystal is in contact with the mixed solution (200) ranging from 2 months to 5 months, the temperature in the growth furnace is reduced by 1.5°C / day.

7. The BBO crystal growth method according to claim 6, characterized in that: Within a fourth preset time range in which the BBO seed crystal is in contact with the mixed solution (200), the temperature in the growth furnace is reduced at a third cooling rate, the third cooling rate being greater than the first cooling rate and less than the second cooling rate, including: During the period of time when the BBO seed crystal is in contact with the mixed solution (200) for 5 to 7 months, the temperature in the growth furnace is reduced by 0.6°C / day.

8. The BBO crystal growth method according to claim 4, characterized in that: Within a second preset time range in which the BBO seed crystal is in contact with the mixed solution (200), the temperature in the growth furnace is reduced at a first cooling rate, comprising: During the time period from 2 days to 1 month when the BBO seed crystal is in contact with the mixed solution (200), the temperature in the growth furnace is reduced by 0.2°C / day.

9. The BBO crystal growth method according to claim 8, characterized in that: Within a third preset time range in which the BBO seed crystal is in contact with the mixed solution (200), the temperature in the growth furnace is reduced at a second cooling rate, wherein the second cooling rate is greater than the first cooling rate, comprising: During the period of time that the BBO seed crystal is in contact with the mixed solution (200) from 1 month to 3 months, the temperature in the growth furnace is reduced by 2°C / day.

10. The BBO crystal growth method according to claim 9, characterized in that: Within a fourth preset time range in which the BBO seed crystal is in contact with the mixed solution (200), the temperature in the growth furnace is reduced at a third cooling rate, the third cooling rate being greater than the first cooling rate and less than the second cooling rate, including: During the period of time when the BBO seed crystal is in contact with the mixed solution (200) for 3 to 5 months, the temperature in the growth furnace is reduced at a rate of 0.6°C / day.

11. The BBO crystal growth method according to any one of claims 1 to 10, characterized in that: A seed crystal rod (120) is arranged in the middle of the crucible (110), and a BBO seed crystal is tied to the end of the seed crystal rod (120) so that the end surface of the BBO seed crystal contacts the liquid surface of the mixed solution (200), and the seed crystal rod (120) is driven to drive the BBO seed crystal to rotate at a preset speed, the method further comprising: The mixed solution (200) is stirred within a first preset time range, a second preset time range, a third preset time range, and a fourth preset time range during which the BBO seed crystal contacts the mixed solution (200).

12. A BBO crystal growth device, applied to the BBO crystal growth method according to any one of claims 1 to 11, characterized in that: The invention comprises a growth furnace and a crucible (110) arranged in the growth furnace, wherein the crucible (110) is used for placing a solution; the invention also comprises a seed crystal rod (120) and a stirring part (130), wherein the seed crystal rod (120) is arranged in the middle of the crucible (110) and is used for binding a BBO seed crystal; the stirring part (130) comprises a stirring blade (132) and a stirring rod (131), wherein the stirring blade (132) is arranged at the end of the stirring rod (131), and one end of the stirring rod (131) away from the stirring blade (132) is fixedly connected to the seed crystal rod (120); the seed crystal rod (120) can drive the stirring part (130) to rotate in the solution of the crucible (110) with the seed crystal rod (120) as the rotation center.

13. The BBO crystal growth device according to claim 12, characterized in that: The number of the stirring parts (130) is two, and the two stirring parts (130) are respectively arranged on two opposite sides of the seed crystal rod (120); the stirring rod (131) has a bending portion so that the stirring blades (132) are located on two opposite sides of the BBO seed crystal.

14. The BBO crystal growth device according to claim 12, characterized in that: The stirring rod (131) has three bent portions, so that the stirring blade (132) is located at the bottom of the crucible (110) and is arranged opposite to the BBO seed crystal.

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