Large-size laser crystal annealing supporting device and annealing method

Abstract

The invention discloses a large-size laser crystal annealing supporting device and an annealing method. The large-size laser crystal annealing supporting device comprises a metal support; the supporting panel is arranged on the metal support, and the supporting panel is a fence-shaped panel composed of a plurality of metal strips. Through the design of the fence-shaped panel, the consistency of the heating and cooling rates of the upper part and the lower part of the crystal can be ensured to the maximum extent, and the temperature gradient in the crystal is reduced. Based on the device, the crystal annealing method provided by the invention can remarkably improve the annealing effect of the large-size laser crystal, effectively reduce the risk of crystal cracking and improve the optical uniformity of the crystal, and has the characteristics of energy conservation and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of large-size laser crystal preparation, and in particular relates to a large-size laser crystal annealing support device, and also relates to a large-size laser crystal annealing method based on the support device. Background Art

[0002] Laser crystals are widely used as an efficient energy conversion medium. The demand for large-sized laser crystals (diameter ≥ 200 mm and weight ≥ 50 kg) is growing due to their higher efficiency and more stable laser output.

[0003] Large-sized laser crystals usually need to be annealed after growth to improve crystal quality and eliminate stress and defects. The traditional annealing method is to place the large-sized laser crystal at the bottom of the annealing furnace. The temperature conduction environment of the upper and lower parts of the crystal is different, resulting in a large temperature gradient inside the crystal. Not only is the crystal annealing stress relief effect poor, it may even cause the crystal to crack. On the other hand, the annealing temperature of large-sized laser crystals is generally as high as 1500℃, and there are also high requirements for the support device for placing the crystal during annealing. Summary of the invention

[0004] In view of this, the primary purpose of the present invention is to provide a large-size laser crystal annealing support device, by which the large-size laser crystal is annealed, the risk of crystal cracking can be reduced to the greatest extent.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention first provides a large-size laser crystal annealing support device, comprising:

[0007] Metal bracket;

[0008] And a supporting panel arranged on the metal bracket, wherein the supporting panel is a fence-shaped panel composed of a plurality of metal strips.

[0009] In the present invention, the metal bracket can be any component that can play a supporting role, which is arranged on the lower surface of the support panel to support the support panel. In some specific embodiments, the metal bracket is composed of a plurality of metal tubes. The "several" mentioned here is not particularly limited, and is based on the ability to achieve stable support. It is preferred to use four or six metal tubes for support. The metal tube described in the present invention can be a solid tube or a hollow tube. In view of factors such as cost, a hollow tube is preferably used. The specific shape is not particularly limited. For example, the cross-section of the metal tube can be circular, square or triangular. It is preferred to select a metal tube with a symmetrical shape to further ensure the stability of the support.

[0010] Furthermore, the metal bracket described in this article needs to have high high temperature resistance and load-bearing performance to ensure the safety of large-sized laser crystals. In some specific embodiments of the present invention, the metal bracket can bear a load of ≥200kg at 1500°C.

[0011] As a further solution, in the present invention, by using a fence-shaped panel as a supporting panel, it is possible to facilitate the circulation of air between the upper and lower parts of the crystal during the annealing process, thereby facilitating heat exchange, maximizing the consistency of the heating and cooling rates of the upper and lower parts of the crystal, and reducing the temperature gradient in the crystal.

[0012] The width and spacing of each metal strip in the support panel can be designed as needed, and the design basis is to ensure the upper and lower air circulation as much as possible under the premise of ensuring the safety of the crystal, that is, the crystal will not fall. In some specific implementation cases of the present invention, in the support panel, the width of the metal strip is 10-20 mm, and the spacing between adjacent metal strips is 30-50 mm.

[0013] Similarly, in order to ensure the safety of the crystal, the support panel also needs to have high high temperature resistance and load-bearing performance, and its load-bearing capacity should be ≥150kg at 1500°C.

[0014] In a further solution, a metal baffle is vertically extended upward along the edge of the support panel. The metal baffle is provided to prevent the crystal from falling and ensure the safety of the crystal. Preferably, the thickness of the metal baffle is ≥2 mm, for example, it can be 2 to 3 mm.

[0015] In a further embodiment, the length or diameter of the support panel is denoted as L s , the height of the support device is denoted as H s ; The length of the large-size laser crystal is denoted as L c , the height or diameter is denoted as H c The length of the annealing furnace body is recorded as L f , the inner height or inner diameter is denoted as H f ;

[0016] Then it is necessary to satisfy L f >L s ≥L c , and [(H f -H c ) / 2]=H s .

[0017] The size of the support device is designed according to the size of the large-sized laser crystal and the annealing furnace body to ensure that the temperature field around the crystal is symmetrical during the annealing operation.

[0018] In a further solution, the materials of the support devices described herein need to be resistant to high temperatures to meet the requirements of high temperature annealing. In some specific embodiments of the present invention, the metal bracket, support panel and metal baffle are all high melting point metals, and the high melting point metal refers to tungsten, molybdenum or tungsten-molybdenum alloy. Preferably, a protective layer is provided on the surface of the metal, which can be formed by a method well known in the art, such as spraying, etc., to isolate the air, avoid oxidation of the metal of the support device, and increase the service life of the support device. It can be understood that the protective layer used also needs to be resistant to high temperatures. In some typical implementation cases of the present invention, the protective layer is a zirconium oxide powder layer with a thickness of ≥1 mm.

[0019] The present invention further provides a large-size laser crystal annealing method, which is based on the supporting device described above and comprises the following steps:

[0020] The supporting device described above is placed in the furnace of the annealing device, and the large-sized laser crystal is placed on the supporting panel of the supporting device so that the centers of the three coincide with each other;

[0021] Perform annealing according to the preset annealing program.

[0022] Specifically, the annealing is divided into a plurality of temperature zones, each temperature zone adopts a different heating and / or cooling rate, and the higher the temperature of the temperature zone, the lower the heating and / or cooling rate.

[0023] This annealing method can maximize the symmetry of the temperature field around the crystal, ensure the consistency of the heating and cooling rates of the upper and lower parts of the crystal, reduce the temperature gradient in the crystal, thereby avoiding the cracking problem that is prone to occur in large-size laser crystals during annealing and improving the quality of large-size laser crystals.

[0024] Beneficial effects of the present invention:

[0025] The large-size laser crystal annealing support device of the present invention adopts a fence-shaped panel as a support panel, which can maximize the consistency of the heating and cooling rates of the upper and lower parts of the crystal and reduce the temperature gradient of the crystal during the annealing process.

[0026] Based on the support device, large-size laser crystals are annealed. By aligning the centers of the support device, the crystal and the annealing furnace body, the symmetry of the temperature field around the crystal is ensured, thereby avoiding the risk of cracking of the large-size laser crystals. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the structure of a supporting device proposed in a preferred embodiment of the present invention.

[0028] Figure 2It is a schematic diagram of the structure of a supporting device proposed in another preferred embodiment of the present invention.

[0029] Figure 3 This is a schematic diagram of the placement structure of a large-size laser crystal during annealing in Example 2 of the present invention.

[0030] In the figure: 10-metal bracket, 20-support panel, 201-metal strip, 202-metal baffle. DETAILED DESCRIPTION

[0031] Embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. 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. In addition, unless otherwise specified, methods that do not specifically record conditions or steps are conventional methods, and the reagents and materials used can be obtained from commercial sources.

[0033] Example 1

[0034] This embodiment provides a structural schematic diagram of a supporting device, the structure of which is as follows: Figure 1 As shown in , the support device includes a metal support 10, a support panel 20 is arranged above the metal support 10, the entire support device is made of tungsten metal, and a zirconium oxide powder layer with a thickness of 1 mm is sprayed on the surface of the tungsten metal.

[0035] The height of the metal bracket 10 is 400 mm, and the metal bracket 10 is composed of a hollow tube formed by four tungsten sheets, and the cross section of the hollow tube is a square. In this embodiment, the minimum load-bearing capacity of the metal bracket 10 at 1500° C. is 200 kg.

[0036] The support panel 20 is a circular fence-shaped panel with a diameter of 600 mm. It is composed of a plurality of metal strips 201. The material of the metal strips 201 is the same as that of the metal bracket 10. The width of the metal strips 201 is 20 mm. One metal strip 201 is arranged along the central axis, and the remaining metal strips 201 are parallel to each other and intersect with the central axis metal strip 201 respectively. The distance between adjacent metal strips 201 is 50 mm. A metal baffle 202 extends vertically upward along the edge of the support panel 20. In this embodiment, the metal baffles 202 are symmetrically arranged at both ends of the central axis metal strip 201. The material of the metal baffles 202 is the same as that of the metal bracket 10. In this embodiment, the thickness of the metal baffles 202 is 2 mm.

[0037] This embodiment further provides a large-size laser crystal annealing method based on the above-mentioned support device, wherein the annealing furnace used is a cylindrical furnace body with an internal size of Annealed crystals are sized Nd-doped yttrium aluminum garnet (Nd:YAG) crystal. The specific steps are as follows:

[0038] Place the support device into the annealing furnace body, and place the Nd:YAG crystal horizontally on the support panel 20, so that the centers of the support panel 20, the annealing furnace body and the Nd:YAG crystal coincide with each other;

[0039] Close the furnace door and set the annealing program, in which the temperature rise program is: from room temperature to 800°C in 12 hours, then to 1200°C in 12 hours, and then to 1500°C in 12 hours; keep 1500°C constant for 7 days; then cool down, the cooling program is: drop to 1200°C in 24 hours, drop to 800°C in 24 hours, and drop to room temperature in 24 hours.

[0040] Example 2

[0041] This embodiment provides a structural schematic diagram of a supporting device, the structure of which is as follows: Figure 2 As shown in , the support device includes a metal support 10, a support panel 20 is arranged above the metal support 10, the entire support device is made of molybdenum metal, and a zirconium oxide powder layer with a thickness of 1 mm is sprayed on the surface of the tungsten metal.

[0042] The height of the metal bracket 10 is 300 mm, and it is composed of a hollow tube formed by six molybdenum sheets, and the cross section of the hollow tube is circular. In this embodiment, the minimum load-bearing capacity of the metal bracket 10 at 1500° C. is 300 kg.

[0043] The support panel 20 is a rectangular fence-shaped panel with a length of 800 mm. It is composed of a plurality of metal strips 201. The material of the metal strips 201 is the same as that of the metal bracket 10. The width of the metal strips 201 is 15 mm. One metal strip 201 is arranged along the central axis, and the remaining metal strips 201 are parallel to each other and intersect with the central axis metal strip 201 respectively. The distance between adjacent metal strips 201 is 40 mm. A metal baffle 202 extends vertically upward along the edge of the support panel 20. In this embodiment, the metal baffles 202 are symmetrically arranged at both ends of the central axis metal strip 201. The material of the metal baffles 202 is the same as that of the metal bracket 10. In this embodiment, the thickness of the metal baffles 202 is 2 mm.

[0044] This embodiment further provides a large-size laser crystal annealing method based on the above-mentioned supporting device, wherein the annealing furnace used is a square furnace body with internal dimensions of 1500mm×1200mm×1000mm (length×width×height); the annealed crystal is a Yb-doped yttrium aluminum garnet (Yb:YAG) crystal with a size of 800mm×500mm×400mm (length×width×height).

[0045] The specific steps are as follows:

[0046] Place the support device into the annealing furnace body, and place the Yb:YAG crystal on the support panel 20, so that the centers of the support panel 20, the annealing furnace body and the Yb:YAG crystal coincide with each other;

[0047] Close the furnace door and set the annealing program, in which the temperature rise program is: from room temperature to 800°C in 12 hours, then to 1300°C after 18 hours, and then to 1600°C after 24 hours; keep 1600°C constant for 7 days; then cool down, the cooling program is: drop to 1300°C in 48 hours, then drop to 800°C after 36 hours, and then drop to room temperature after 24 hours.

[0048] The Nd:YAG crystal and the Yb:YAG crystal obtained by the annealing method in Example 1 and Example 2 of the present invention are not cracked, and the optical uniformity is improved.

[0049] Comparative Example 1

[0050] This comparative example adopts the same implementation as Example 1, with the only difference being that the centers of the annealing furnace body and the Nd:YAG crystal do not coincide.

[0051] In this comparative example, crystal cracking was found after annealing.

[0052] Comparative Example 2

[0053] This comparative example adopts the same implementation as Example 2, with the only difference being that the annealing support device of Example 2 is not used, but the crystal is placed directly on the bottom of the furnace.

[0054] In this comparative example, it was found that the crystal did not crack after annealing, but the optical uniformity was not effectively improved.

[0055] Comparative Example 3

[0056] This comparative example adopts the same implementation as comparative example 2, except that the constant temperature time is 14 days.

[0057] In this comparative example, it was found that the crystal did not crack after annealing, and the optical uniformity was also effectively improved.

[0058] From the above embodiments and comparative examples, it can be seen that by using the annealing support device of the present invention to anneal a large-size laser crystal, not only the crystal does not crack and has excellent optical uniformity, but also the annealing time is shortened, the annealing effect can be obtained in a shorter time, and the annealing effect and annealing efficiency of the large-size laser crystal are improved.

[0059] 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.

[0060] 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 large-size laser crystal annealing support device, characterized in that: include: Metal bracket; And a supporting panel arranged on the metal bracket, wherein the supporting panel is a fence-shaped panel composed of a plurality of metal strips.

2. The large-size laser crystal annealing support device according to claim 1, characterized in that: The metal bracket is composed of a plurality of metal tubes, which are arranged on the lower surface of the support panel and are used to support the support panel; Preferably, the metal tube is a hollow tube, and the cross-section of the hollow tube is circular, square or triangular.

3. The large-size laser crystal annealing support device according to claim 1, characterized in that: The metal bracket can bear a load of ≥200kg at 1500°C.

4. The large-size laser crystal annealing support device according to claim 1, characterized in that: In the support panel, the width of the metal strips is 10-20 mm, and the spacing between adjacent metal strips is 30-50 mm.

5. The large-size laser crystal annealing support device according to claim 1, characterized in that: The support panel has a load-bearing capacity of ≥150kg at 1500°C.

6. The large-size laser crystal annealing support device according to claim 1, characterized in that: A metal baffle extends vertically upward along the edge of the support panel, and the thickness of the metal baffle is ≥2mm.

7. The large-size laser crystal annealing support device according to claim 1, characterized in that: The length or diameter of the support panel is denoted as L s , the height of the support device is denoted as H s ; The length of the large-size laser crystal is denoted as L c , the height or diameter is denoted as H c The length of the annealing furnace body is recorded as L f , the inner height or inner diameter is denoted as H f ; Then it is necessary to satisfy L f >L s ≥L c , and [(H f -H c ) / 2]=H s .

8. The large-size laser crystal annealing support device according to any one of claims 1 to 7, characterized in that: The support device is made of high melting point metal and has a protective layer on the surface; Preferably, the high melting point metal is tungsten, molybdenum or tungsten-molybdenum alloy; And / or, the protective layer is a zirconium oxide powder layer with a thickness of ≥1 mm.

9. A method for annealing a large-size laser crystal, based on the support device according to any one of claims 1 to 8, characterized in that: The following steps are involved: Placing the support device according to any one of claims 1 to 8 in the furnace body of the annealing device, and placing the large-sized laser crystal on the support panel of the support device so that the centers of the three coincide; Perform annealing according to the preset annealing program.

10. The large-size laser crystal annealing method according to claim 9, characterized in that: The annealing is divided into a plurality of temperature zones, each temperature zone adopts a different heating and / or cooling rate, and the higher the temperature of the temperature zone, the lower the heating and / or cooling rate.

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