A method, device and system for visual monitoring of crystal growth

Abstract

The present invention relates to a method, device and system for visual monitoring of crystal growth, the method comprising: obtaining a crystal growth image in a crystal growth furnace; processing the crystal growth image, extracting reflective aperture data on the interface between solid and liquid; modeling the outer edge of the crystal growth layer by layer during the pulling growth process according to the reflective aperture data, obtaining a crystal growth morphology image and displaying it. The present invention obtains the aperture through the image of the crystal in the crystal growth furnace to reconstruct the crystal contour, monitor the crystal growth process, and facilitate the subsequent control of the crystal growth quality.

Description

Technical Field

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

[0002] In applications such as laser communications, laser resonators, and nonlinear optics, the growth quality of optical crystal materials is very important and has a great impact on the performance of optical components. For example, during the crystal growth process, the growth rate, growth shape, and posture of the crystal seeding and shoulder expansion stages are very important for subsequent crystal growth.

[0003] At present, the growth process of crystals is generally monitored manually. The reference data for manual monitoring includes the weight of the crystal transmitted by the weighing device on the lifting rod, but due to factors such as seed crystal rotation, melt flow, melt surface tension, and mechanical and airflow disturbances, accurate values ​​cannot be obtained. Therefore, it is still necessary to use naked eyes and CCD cameras for observation in the early stage. The growth of crystals can be judged by images at different times. The disadvantage is that it is impossible to accurately describe the morphological characteristics and size data of the crystals, and the whole process requires manual participation. With the popularization of intelligence, there is an urgent need to digitally monitor the morphology of crystals during crystal growth. It is very important to obtain numerical characteristics such as the radius and shape of the crystal during the crystal growth process. Summary of the invention

[0004] Based on this, it is necessary to provide a method, device and system for visual monitoring of crystal growth in response to the above-mentioned technical problems existing in the prior art. The present invention obtains the aperture through the image of the crystal in the crystal growth furnace to reconstruct the crystal contour and monitor the crystal growth process, which is convenient for subsequent control of the crystal growth quality.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A method for visually monitoring crystal growth, comprising:

[0007] Acquire a crystal growth image in a crystal growth furnace;

[0008] Process the crystal growth image and extract the reflective aperture data on the interface between solid and liquid;

[0009] According to the reflective aperture data, the outer edge of the crystal growth is modeled layer by layer during the pulling growth process, and the crystal growth morphology image is obtained and displayed;

[0010] The crystal growth images include crystal growth images at different rotation angles and different heights;

[0011] Preferably, the camera is aligned with the center of the seed crystal when acquiring the crystal growth image;

[0012] Preferably, the crystal growth image is processed to extract the reflective aperture data on the interface between the solid and the liquid, including:

[0013] Slicing: collecting a row of data on the slice line on the crystal growth image. The slice line intersects with the boundary line between the solid and the liquid and is perpendicular to the pulling direction of the seed crystal.

[0014] Smoothing: smoothing a row of data on the slice line;

[0015] Aperture extraction: extracting the peak value of one aperture from the smoothed data;

[0016] Preferably, the slicing line intersects the boundary line between the solid and the liquid at the center of the boundary line between the solid and the liquid;

[0017] Preferably, one of Fourier transform filtering, convolution smoothing or Savitzky-Golay smoothing is used to smooth a row of data on the slice line;

[0018] Preferably, in the smoothed data, a derivative, a Canny edge detection operator or deep learning is used to obtain the peak value of one of the apertures.

[0019] Preferably, the outer edge of the crystal growth is modeled layer by layer during the pulling growth process according to the reflective aperture data, and the crystal growth morphology image is obtained and displayed, including:

[0020] Rotation edge reconstruction: Slicing, smoothing and aperture extraction operations are performed on crystal growth images at different rotation angles to obtain the solid-liquid interface edge at the corresponding height;

[0021] Lifting edge reconstruction: Slicing, smoothing, aperture extraction and rotation edge reconstruction operations are performed on crystal growth images at different heights to obtain solid-liquid interface edges at different heights;

[0022] Contour reconstruction forms and displays the crystal growth morphology image according to the height and solid-liquid interface edge.

[0023] In order to solve the above technical problems, another technical solution adopted by the present invention is:

[0024] The visual monitoring method for crystal growth as described above is used to visually monitor the growth process of a crystal grown using the Czochralski method, wherein the crystal includes lithium niobate, lithium tantalate, artificial yttrium aluminum garnet, and artificial gadolinium gallium garnet.

[0025] In order to solve the above technical problems, another technical solution adopted by the present invention is:

[0026] A visual monitoring device for crystal growth, comprising:

[0027] An image acquisition module, for acquiring a crystal growth image in the crystal growth furnace;

[0028] Aperture extraction module, which processes the crystal growth image and extracts the reflective aperture data on the interface between solid and liquid;

[0029] The contour reconstruction module models the outer edge of the crystal layer by layer during the pulling growth process according to the reflective aperture data, obtains the crystal growth morphology image and displays it;

[0030] The crystal growth images include crystal growth images at different rotation angles and different heights;

[0031] Preferably, the camera is aligned with the center of the seed crystal when acquiring the crystal growth image;

[0032] Preferably, the aperture extraction module comprises:

[0033] Slicing: collecting a row of data on the slice line on the crystal growth image. The slice line intersects with the boundary line between the solid and the liquid and is perpendicular to the pulling direction of the seed crystal.

[0034] Smoothing: smoothing a row of data on the slice line;

[0035] Aperture extraction: extracting the peak value of one aperture from the smoothed data;

[0036] Preferably, the slicing line intersects the boundary line between the solid and the liquid at the center of the boundary line between the solid and the liquid;

[0037] Preferably, one of Fourier transform filtering, convolution smoothing or Savitzky-Golay smoothing is used to smooth a row of data on the slice line;

[0038] Preferably, in the smoothed data, a derivative, a Canny edge detection operator or deep learning is used to obtain the peak value of one of the apertures.

[0039] Preferably, the contour reconstruction module comprises:

[0040] Rotation edge reconstruction: Slicing, smoothing and aperture extraction operations are performed on crystal growth images at different rotation angles to obtain the solid-liquid interface edge at the corresponding height;

[0041] Lifting edge reconstruction: Slicing, smoothing, aperture extraction and rotation edge reconstruction operations are performed on crystal growth images at different heights to obtain solid-liquid interface edges at different heights;

[0042] Contour reconstruction forms and displays the crystal growth morphology image according to the height and solid-liquid interface edge.

[0043] In order to solve the above technical problems, another technical solution adopted by the present invention is:

[0044] A computer-readable storage medium stores program information. After a computer reads the program information, the computer executes the visual monitoring method for crystal growth as described above.

[0045] In order to solve the above technical problems, another technical solution adopted by the present invention is:

[0046] An electronic device includes at least one processor and at least one memory, wherein program information is stored in the at least one memory, and the at least one processor reads the program information and executes the above-mentioned visual monitoring method for crystal growth.

[0047] In order to solve the above technical problems, another technical solution adopted by the present invention is:

[0048] A crystal growth visual monitoring system is used to visually monitor the growth process of the crystal, the system comprising:

[0049] A crystal growth assembly, used for crystal growth, comprising a crystal growth furnace, a heat preservation cover, and a crucible, wherein the crucible is arranged in the crystal growth furnace and the heat preservation cover is arranged on the crystal growth furnace;

[0050] A monitoring assembly, disposed on a side wall of the crystal growth furnace, comprising a camera;

[0051] A control assembly is arranged outside the crystal growth furnace and includes a controller;

[0052] The camera captures the crystal growth image in the crystal growth furnace and sends it to the controller; after acquiring the crystal growth image in the crystal growth furnace, the controller processes the crystal growth image, extracts the reflective aperture data on the interface between the solid and the liquid, and models the growing outer edge of the crystal layer by layer during the pulling growth process according to the reflective aperture data, obtains the crystal growth morphology image and displays it.

[0053] Preferably, a reflective layer is provided on the inner wall of the heat-insulating cover and the crystal growth furnace;

[0054] Preferably, the reflective layer is a platinum layer or a ceramic layer;

[0055] Preferably, the reflective layer on the inner wall of the crystal growth furnace is higher than the crucible;

[0056] Preferably, the crystal growth images include crystal growth images at different rotation angles and different heights;

[0057] Preferably, the camera is aligned with the center of the seed crystal when taking the crystal growth image;

[0058] Preferably, the crystal growth image is processed to extract the reflective aperture data on the interface between the solid and the liquid, including:

[0059] Slicing: collecting a row of data on the slice line on the crystal growth image. The slice line intersects with the boundary line between the solid and the liquid and is perpendicular to the pulling direction of the seed crystal.

[0060] Smoothing: smoothing a row of data on the slice line;

[0061] Aperture extraction: extracting the peak value of one aperture from the smoothed data;

[0062] Preferably, the slicing line intersects the boundary line between the solid and the liquid at the center of the boundary line between the solid and the liquid;

[0063] Preferably, one of Fourier transform filtering, convolution smoothing or Savitzky-Golay smoothing is used to smooth a row of data on the slice line;

[0064] Preferably, in the smoothed data, a derivative, a Canny edge detection operator or deep learning is used to obtain the peak value of one of the apertures.

[0065] Preferably, the outer edge of the crystal growth is modeled layer by layer during the pulling growth process according to the reflective aperture data, and the crystal growth morphology image is obtained and displayed, including:

[0066] Rotation edge reconstruction: Slicing, smoothing and aperture extraction operations are performed on crystal growth images at different rotation angles to obtain the solid-liquid interface edge at the corresponding height;

[0067] Lifting edge reconstruction: Slicing, smoothing, aperture extraction and rotation edge reconstruction operations are performed on crystal growth images at different heights to obtain solid-liquid interface edges at different heights;

[0068] Contour reconstruction forms and displays the crystal growth morphology image according to the height and solid-liquid interface edge.

[0069] Due to the adoption of the above technical solution, the present invention has the following advantages compared with the prior art:

[0070] 1. The present invention uses a camera placed in an observation hole to capture images of crystal growth, extracts the reflective aperture on the interface between solid and liquid, models the outer edge of the crystal growth layer by layer during the pulling growth process, obtains characteristic parameters of the crystal shape, obtains the crystal growth morphology during the growth process, monitors the crystal growth process, and facilitates control and adjustment of the process according to the crystal growth process to ensure that the crystal growth result meets the requirements;

[0071] 2. The present invention adds a platinum reflective layer on the inner wall of the heat-insulating cover and the crystal growth furnace to improve the reflectivity, increase the image contrast, and facilitate the extraction of the reflective aperture. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1 This is the solid-liquid interface image at the seeding stage;

[0073] Figure 2 Aperture formation for the solid-liquid interface;

[0074] Figure 3 is a flow chart of the visual monitoring method of the present invention;

[0075] Figure 4 Schematic diagram of image slicing;

[0076] Figure 5 It is the image slice data diagram, X is the image width, and Y is the image luminous intensity;

[0077] Figure 6 is a smoothed plot of the slice data;

[0078] Figure 7 Reconstruct the image for the rotated edge;

[0079] Figure 8 This is the structure diagram of the seeding stage;

[0080] Fig. 9 Reconstruction of the rotating edge during the seeding stage;

[0081] Fig.10 Reconstruct a top view of the crystal;

[0082] Fig.11 Reconstruct the outline main view for the crystal;

[0083] Fig.12 is a structural block diagram of the visual monitoring device of the present invention;

[0084] Fig.13 It is a structural schematic diagram of the visual monitoring system of the present invention.

[0085] Among them, 1. Crystal growth furnace; 2. Insulation cover; 3. Crucible; 4. Lifting rod; 5. Induction coil; 6. Reflection layer; 7. Camera; 8. Controller; 9. Seed crystal. DETAILED DESCRIPTION

[0086] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0087] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0088] At present, the growth process of crystals is generally monitored manually. The reference data for manual monitoring includes the weight of the crystal transmitted by the weighing device on the lifting rod, but due to factors such as seed crystal rotation, melt flow, melt surface tension, and mechanical and air flow disturbances, accurate values ​​cannot be obtained. With the popularization of intelligence, there is an urgent need to digitally monitor the morphology of crystals during crystal growth, among which it is very important to obtain numerical characteristics such as the radius and shape of the crystal during the crystal growth process.

[0089] On this basis, the present invention provides a method, device and system for visual monitoring of crystal growth, the method comprising: acquiring a crystal growth image in a crystal growth furnace; processing the crystal growth image to extract reflective aperture data on the interface between solid and liquid; modeling the growing outer edge of the crystal layer by layer during the pulling growth process according to the reflective aperture data, obtaining and displaying a crystal growth morphology image.

[0090] The present invention obtains an aperture through an image of the crystal in a crystal growth furnace to reconstruct the crystal contour and monitor the crystal growth process, thereby facilitating subsequent control of the crystal growth quality.

[0091] The visual monitoring method of crystal growth of the present invention is used for visually monitoring the growth process of crystals grown by the Czochralski method, such crystals include lithium niobate, lithium tantalate, artificial yttrium aluminum garnet (YAG), artificial gadolinium gallium garnet (GGG), etc. In the following description, the present invention takes lithium niobate crystal as an example.

[0092] The specific shape of the aperture is as follows Figure 1 As shown in the figure, the light ring surrounds the crystal and is a brighter area at the solid-liquid interface. This area is an important feature for measuring the growth edge of the crystal.

[0093] The aperture is formed due to Figure 2The curved surface at the interface between a liquid and a solid is shown. Because liquids have surface tension and solids and liquids have different surface energies, the contact between liquids and solids has both hydrophilic and hydrophobic characteristics. For lithium niobate melts and lithium niobate crystals, this hydrophilicity causes the liquid surface to rise and bend around the growing edge of the crystal.

[0094] This aperture is easy to observe in a high-temperature crystal growth furnace and is generally brighter. The reason why the aperture is brighter is that in a crystal growth furnace, the high temperature causes black body radiation to be in the visible wavelength, and there are multiple radiation sources in the furnace, generally the induction coil, crucible, melt and insulation material at the bottom. These lights are more easily reflected by the curved aperture into the observation hole where the eye is located, because the curved aperture can reflect light at multiple angles, while the flat liquid surface only reflects light in a specific direction.

[0095] The present invention is described in detail below with reference to specific embodiments.

[0096] like Figure 3 As shown, a method for visually monitoring crystal growth comprises:

[0097] S1, acquiring a crystal growth image in a crystal growth furnace.

[0098] The crystal growth image in the crystal growth furnace can be captured in real time by a device with a shooting function such as a camera or an industrial camera, and the captured image can be sent to the controller.

[0099] In this embodiment, the crystal growth images include crystal growth images at different rotation angles and different heights. When acquiring the crystal growth images, the camera is aligned with the center of the seed crystal at the beginning of crystal growth, and the camera is installed in the observation hole on the crystal growth furnace.

[0100] S2, processes the crystal growth image and extracts the reflective aperture data on the interface between the solid and the liquid.

[0101] In this embodiment, the crystal growth image is processed to extract the reflective aperture data on the interface between the solid and the liquid, including:

[0102] Slice, such as Figure 4 As shown in FIG. 1 , a line of grayscale data on the slice line on the crystal growth image is collected by slicing. The slice line intersects with the boundary line between the solid and the liquid and is perpendicular to the pulling direction of the seed crystal. The collected data is shown in FIG. Figure 5 In this embodiment, the slice line intersects the boundary line between the solid and the liquid at the center of the boundary line between the solid and the liquid.

[0103] from Figure 5 From the slice data, we can see that the lower part in the middle of the image is the seed crystal, and the higher part is the liquid surface.

[0104] Smoothing, smoothing a row of data on the slice line. Specifically, one of the Fourier transform filtering method, the convolution smoothing method or the Savitzky-Golay smoothing method can be used to smooth a row of data on the slice line. Figure 6 As shown, in this embodiment, the Savitzky-Golay smoothing method is used to obtain the smoothing effect. From the smoothed curve, it can be seen that the protrusions on both sides of the central concave valley are apertures.

[0105] Aperture extraction: extract the peak value closest to the center of the concave valley from the smoothed data, that is, the peak value of an aperture. In this embodiment, the peak value of an aperture can be obtained by taking a derivative, a Canny edge detection operator, or deep learning from the smoothed data. For example, Figure 6 The pixel coordinates of the peak value corresponding to the left aperture of are (807, 156). The pixel point can be matched one-to-one with the actual size, for example, by marking an object with a known size.

[0106] S3, modeling the outer edge of the crystal layer by layer during the pulling growth process according to the reflective aperture data, obtaining and displaying the crystal growth morphology image.

[0107] In this embodiment, the outer edge of the crystal growth is modeled layer by layer during the pulling growth process according to the reflective aperture data, and the crystal growth morphology image is obtained and displayed, including:

[0108] Rotational edge reconstruction: Slicing, smoothing and aperture extraction operations are performed on crystal growth images at different rotation angles to obtain the solid-liquid interface edge at the corresponding height.

[0109] In this embodiment, as the lifting rod rotates, images at different rotation angles are captured multiple times, and the images are matched one-to-one with the rotation angles, thereby obtaining the overall solid-liquid interface edge contour at the corresponding height, such as Figure 7 shown.

[0110] The lifting edge reconstruction is to slice, smooth, extract aperture and rotate the edge reconstruction operations on the crystal growth images at different heights to obtain the solid-liquid interface edges at different heights.

[0111] In the crystal growth of this embodiment, the pulling rod is pulled while rotating, and the above-mentioned slicing, smoothing, aperture extraction and rotation edge reconstruction operations are repeated at a certain pulling height to obtain the solid-liquid interface edge at different heights. Figure 8 In the seeding stage shown in FIG. 1 , slicing, smoothing, aperture extraction and rotation edge reconstruction are performed as described above to obtain the rotation edge reconstruction of the height as shown in FIG. Fig. 9 shown.

[0112] Contour reconstruction forms and displays the crystal growth morphology image according to the height and solid-liquid interface edge.

[0113] In this embodiment, the edge reconstruction is repeated in sequence to obtain solid-liquid interface edges of different heights, and a three-dimensional outline of the crystal growth morphology image is formed and displayed according to the height and solid-liquid interface edge, such as Fig.10 , Fig.11 shown.

[0114] This embodiment also provides a visual monitoring device for the growth of lithium niobate crystals, such as Fig.12 As shown, the device comprises:

[0115] An image acquisition module, for acquiring a crystal growth image in the crystal growth furnace;

[0116] Aperture extraction module, which processes the crystal growth image and extracts the reflective aperture data on the interface between solid and liquid;

[0117] The contour reconstruction module models the outer edge of the crystal layer by layer during the pulling growth process according to the reflective aperture data, obtains and displays the crystal growth morphology image.

[0118] In this embodiment, the crystal growth images include crystal growth images at different rotation angles and different heights. When acquiring the crystal growth images, the camera is kept aligned with the center of the seed crystal at the beginning of crystal growth.

[0119] In this embodiment, the aperture extraction module includes:

[0120] Slicing, through slicing, collect a line of data on the slice line on the crystal growth image, the slice line intersects with the boundary line between the solid and the liquid and is perpendicular to the pulling direction of the seed crystal. Specifically, the slice line intersects with the boundary line between the solid and the liquid at the center of the boundary line between the solid and the liquid.

[0121] Smoothing, smoothing a row of data on the slice line. Specifically, one of Fourier transform filtering method, convolution smoothing method or Savitzky-Golay smoothing method is used to smooth a row of data on the slice line.

[0122] Aperture extraction, extracting the peak value closest to the fovea in the smoothed data, that is, the peak value of an aperture. Specifically, a derivative, a Canny edge detection operator or deep learning is used in the smoothed data to obtain the peak value of one of the apertures.

[0123] In this embodiment, the contour reconstruction module includes:

[0124] Rotation edge reconstruction: Slicing, smoothing and aperture extraction operations are performed on crystal growth images at different rotation angles to obtain the solid-liquid interface edge at the corresponding height;

[0125] Lifting edge reconstruction: Slicing, smoothing, aperture extraction and rotation edge reconstruction operations are performed on crystal growth images at different heights to obtain solid-liquid interface edges at different heights;

[0126] Contour reconstruction forms and displays the crystal growth morphology image according to the height and solid-liquid interface edge.

[0127] This embodiment also provides a computer-readable storage medium, in which program information is stored. After the computer reads the program information, the visual monitoring method for the growth of lithium niobate crystals as described above is executed.

[0128] It is understandable that the storage may be a magnetic medium, such as a floppy disk, a hard disk, or a magnetic tape; an optical medium, such as a DVD; or a semiconductor medium, such as a solid state disk (SSD).

[0129] This embodiment also provides an electronic device, including at least one processor and at least one memory, wherein the at least one memory stores program information, and the at least one processor reads the program information and executes the visual monitoring method for lithium niobate crystal growth as described above.

[0130] This embodiment also provides a visual monitoring system for lithium niobate crystal growth, which is used to visually monitor the growth process of lithium niobate crystals. Fig.13 As shown, the system includes:

[0131] A crystal growth assembly is used for growing lithium niobate crystals, comprising a crystal growth furnace 1, a heat preservation cover 2, a crucible 3, a lifting rod 4, and an induction coil 5. The crucible 3 is arranged in the crystal growth furnace 1 for placing lithium niobate melt, the heat preservation cover 2 is arranged on the crystal growth furnace 1, the lifting rod 4 is arranged on the heat preservation cover 2 for upward and downward movement, the lifting rod 4 can rotate along its own axis, a seed crystal 9 is arranged at the lower end of the lifting rod 4, and the induction coil 5 is arranged on the outside of the crucible 3 for heating the crucible 3.

[0132] The monitoring component is arranged on the side wall of the crystal growth furnace 1, and includes a camera 7. In this embodiment, an observation hole is arranged on the side wall of the crystal growth furnace 1, and the camera 7 is installed in the observation hole.

[0133] The control component is arranged outside the crystal growth furnace 1 , and includes a controller 8 .

[0134] In this embodiment, the camera 7 captures the crystal growth image in the crystal growth furnace 1 and sends it to the controller 8; after acquiring the crystal growth image in the crystal growth furnace 1, the controller 8 processes the crystal growth image, extracts the reflective aperture data on the interface between the solid and the liquid, and models the growing outer edge of the crystal layer by layer according to the reflective aperture data during the pulling growth process, obtains the crystal growth morphology image and displays it.

[0135] In this embodiment, in order to increase the brightness of the aperture, improve the light intensity of the upper part of the crystal growth furnace 1, and allow more reflected light to enter the observation hole through the aperture, the present invention provides a reflective layer 6 on the inner wall of the thermal insulation cover 2 and the inner wall of the crystal growth furnace 1 to improve the reflectivity. Specifically, the reflective layer 6 may be a platinum layer or a ceramic layer.

[0136] In some other specific embodiments, in order to save costs and improve reflectivity, the reflective layer 6 on the inner wall of the crystal growth furnace 1 can be higher than the crucible 3, that is, the lowest point of the reflective layer 6 on the inner wall of the crystal growth furnace 1 is higher than the upper end of the crucible 3, so that the reflected light passing through the aperture is enhanced.

[0137] In this embodiment, the crystal growth images include crystal growth images at different rotation angles and different heights. When taking the crystal growth images, the camera 7 is kept aligned with the center of the seed crystal 9 at the beginning of crystal growth.

[0138] In this embodiment, the crystal growth image is processed to extract the reflective aperture data on the interface between the solid and the liquid, including:

[0139] Slicing, collecting a row of data on a slice line on the crystal growth image through slicing, the slice line intersects with the boundary line between the solid and the liquid and is perpendicular to the pulling direction of the seed crystal. Specifically, the slice line intersects with the boundary line between the solid and the liquid at the center of the boundary line between the solid and the liquid;

[0140] Smoothing, smoothing a row of data on the slice line. Specifically, one of Fourier transform filtering, convolution smoothing or Savitzky-Golay smoothing is used to smooth a row of data on the slice line.

[0141] Aperture extraction, extracting the peak value closest to the fovea in the smoothed data, that is, the peak value of an aperture. Specifically, a derivative, a Canny edge detection operator or deep learning is used in the smoothed data to obtain the peak value of one of the apertures.

[0142] In this embodiment, the outer edge of the crystal growth is modeled layer by layer during the pulling growth process according to the reflective aperture data, and the crystal growth morphology image is obtained and displayed, including:

[0143] Rotation edge reconstruction: Slicing, smoothing and aperture extraction operations are performed on crystal growth images at different rotation angles to obtain the solid-liquid interface edge at the corresponding height;

[0144] Lifting edge reconstruction: Slicing, smoothing, aperture extraction and rotation edge reconstruction operations are performed on crystal growth images at different heights to obtain solid-liquid interface edges at different heights;

[0145] Contour reconstruction forms and displays the crystal growth morphology image according to the height and solid-liquid interface edge.

[0146] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0147] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for visually monitoring crystal growth, characterized in that: include: Acquire a crystal growth image in a crystal growth furnace; Processing the crystal growth image to extract reflective aperture data on the interface between the solid and the liquid; Modeling the outer edge of the crystal layer by layer during the pulling growth process according to the reflective aperture data, obtaining and displaying a crystal growth morphology image; Wherein, the crystal growth images include crystal growth images at different rotation angles and different heights; When acquiring the crystal growth image, the camera is aligned with the center of the seed crystal; Processing the crystal growth image to extract reflective aperture data on the interface between the solid and the liquid includes: Slicing, collecting a row of data on a slice line on the crystal growth image, wherein the slice line intersects with the boundary line between the solid and the liquid and is perpendicular to the pulling direction of the seed crystal; Smoothing, smoothing a row of data on the slice line; Aperture extraction: extracting the peak value of one aperture from the smoothed data; Wherein, the slicing line intersects with the boundary line between the solid and the liquid at the center of the boundary line between the solid and the liquid; Smoothing a row of data on the slice line using one of Fourier transform filtering, convolution smoothing or Savitzky-Golay smoothing; In the smoothed data, a derivative, a Canny edge detection operator or deep learning is used to obtain a peak value of one of the apertures.

2. The method for visually monitoring crystal growth according to claim 1, characterized in that: According to the reflective aperture data, the outer edge of the crystal growth is modeled layer by layer during the pulling growth process, and a crystal growth morphology image is obtained and displayed, including: Rotation edge reconstruction: Slicing, smoothing and aperture extraction operations are performed on crystal growth images at different rotation angles to obtain the solid-liquid interface edge at the corresponding height; Lifting edge reconstruction: Slicing, smoothing, aperture extraction and rotation edge reconstruction operations are performed on crystal growth images at different heights to obtain solid-liquid interface edges at different heights; Contour reconstruction forms and displays the crystal growth morphology image according to the height and solid-liquid interface edge.

3. The method for visually monitoring crystal growth according to any one of claims 1 to 2, characterized in that: Used for visually monitoring the growth process of crystals grown by the Czochralski method, wherein the crystals include lithium niobate, lithium tantalate, artificial yttrium aluminum garnet, and artificial gadolinium gallium garnet.

4. A visual monitoring device for crystal growth, characterized in that: include: An image acquisition module, for acquiring a crystal growth image in the crystal growth furnace; An aperture extraction module processes the crystal growth image to extract reflective aperture data on the interface between the solid and the liquid; A contour reconstruction module, which models the outer edge of the crystal layer by layer during the pulling growth process according to the reflective aperture data, obtains and displays a crystal growth morphology image; Wherein, the crystal growth images include crystal growth images at different rotation angles and different heights; When acquiring the crystal growth image, the camera is aligned with the center of the seed crystal; The aperture extraction module comprises: Slicing, collecting a row of data on a slice line on the crystal growth image, wherein the slice line intersects with the boundary line between the solid and the liquid and is perpendicular to the pulling direction of the seed crystal; Smoothing, smoothing a row of data on the slice line; Aperture extraction: extracting the peak value of one aperture from the smoothed data; Wherein, the slicing line intersects with the boundary line between the solid and the liquid at the center of the boundary line between the solid and the liquid; Smoothing a row of data on the slice line using one of Fourier transform filtering, convolution smoothing or Savitzky-Golay smoothing; In the smoothed data, a derivative, a Canny edge detection operator or deep learning is used to obtain a peak value of one of the apertures.

5. The visual monitoring device for crystal growth according to claim 4, characterized in that: The contour reconstruction module comprises: Rotation edge reconstruction: Slicing, smoothing and aperture extraction operations are performed on crystal growth images at different rotation angles to obtain the solid-liquid interface edge at the corresponding height; Lifting edge reconstruction: Slicing, smoothing, aperture extraction and rotation edge reconstruction operations are performed on crystal growth images at different heights to obtain solid-liquid interface edges at different heights; Contour reconstruction forms and displays the crystal growth morphology image according to the height and solid-liquid interface edge.

6. A computer-readable storage medium, characterized in that: The storage medium stores program information, and the computer reads the program information to execute the method for visually monitoring crystal growth according to any one of claims 1 to 2.

7. An electronic device, characterized in that: The method comprises at least one processor and at least one memory, wherein at least one of the memories stores program information, and at least one of the processors reads the program information and executes the method for visually monitoring crystal growth according to any one of claims 1 to 2.

8. A crystal growth visual monitoring system, used to implement the crystal growth visual monitoring method according to any one of claims 1 to 2, characterized in that: The system includes: A crystal growth assembly, used for crystal growth, comprising a crystal growth furnace, a heat preservation cover, and a crucible, wherein the crucible is arranged in the crystal growth furnace, and the heat preservation cover is arranged on the crystal growth furnace; A monitoring component, disposed on a side wall of the crystal growth furnace, comprising a camera; A control component, disposed outside the crystal growth furnace, comprising a controller; The camera captures the crystal growth image in the crystal growth furnace and sends it to the controller; after acquiring the crystal growth image in the crystal growth furnace, the controller processes the crystal growth image, extracts the reflective aperture data on the interface between the solid and the liquid, and models the growing outer edge of the crystal layer by layer during the pulling growth process according to the reflective aperture data, obtains the crystal growth morphology image and displays it.

9. The crystal growth visual monitoring system according to claim 8, characterized in that: The heat-insulating cover and the inner wall of the crystal growth furnace are both provided with a reflective layer; Wherein, the reflective layer is a platinum layer or a ceramic layer; The reflective layer on the inner wall of the crystal growth furnace is higher than the crucible; The crystal growth images include crystal growth images at different rotation angles and different heights; When taking the crystal growth image, the camera is aligned with the center of the seed crystal; Processing the crystal growth image to extract reflective aperture data on the interface between the solid and the liquid includes: Slicing, collecting a row of data on a slice line on the crystal growth image, wherein the slice line intersects with the boundary line between the solid and the liquid and is perpendicular to the pulling direction of the seed crystal; Smoothing, smoothing a row of data on the slice line; Aperture extraction: extracting the peak value of one aperture from the smoothed data; The slicing line intersects the boundary line between the solid and the liquid at the center of the boundary line between the solid and the liquid; Smoothing a row of data on the slice line using one of Fourier transform filtering, convolution smoothing or Savitzky-Golay smoothing; In the smoothed data, a derivative, a Canny edge detection operator or deep learning is used to obtain a peak value of one of the apertures.

10. The crystal growth visual monitoring system according to claim 8, characterized in that: According to the reflective aperture data, the outer edge of the crystal growth is modeled layer by layer during the pulling growth process, and a crystal growth morphology image is obtained and displayed, including: Rotation edge reconstruction: Slicing, smoothing and aperture extraction operations are performed on crystal growth images at different rotation angles to obtain the solid-liquid interface edge at the corresponding height; Lifting edge reconstruction: Slicing, smoothing, aperture extraction and rotation edge reconstruction operations are performed on crystal growth images at different heights to obtain solid-liquid interface edges at different heights; Contour reconstruction forms and displays the crystal growth morphology image according to the height and solid-liquid interface edge.

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