Device for single domain of large-size lithium niobate crystal

Abstract

The device comprises a lower electrode plate, an upper electrode plate and an annular lithium niobate ring block, an opening in the lower end of the lithium niobate ring block is placed on the lower electrode plate, lithium niobate powder is filled in the lithium niobate ring block, the lithium niobate crystal is embedded in the lithium niobate powder, and the upper electrode plate is arranged on the lower electrode plate. The lithium niobate ring block is formed by mixing the lithium niobate powder with glue and sintering the mixture after long-term curing. The crystal is put into the ring block for polarization, the mode is simple and convenient, the problem that polarization is incomplete due to the fact that a traditional crystal powder cap is easy to fall off and warp edges does not exist, and the problems that a niobium oxide pot is high in cost and needs outsourcing manufacturing, and the niobium oxide pot is easy to cause Li diffusion do not exist. And glue is not needed in the polarization process, so that the polarization sufficiency can be ensured, and the use and cost of the glue are saved.

Description

Technical Field

[0001] This utility model relates to the field of lithium niobate crystal processing technology, specifically to a device for single-domain processing of large-size lithium niobate crystals. Background Technology

[0002] Because native lithium niobate crystals of the same composition have a multi-domain structure, the spontaneous polarization direction within each domain is the same, but the spontaneous polarization direction between different domains may be different. Lithium niobate polarization is achieved by applying an external electric field to unify the polarization directions of these domains, thus obtaining a crystal with a consistent polarization direction. In the traditional Z-axis vertical polarization process, a polycrystalline cap is made by mixing crystal powder with glue, which is prone to edge warping or powder detachment during high-temperature polarization, leading to incomplete polarization. X-axis lithium niobate requires applying current to the cylindrical surface. For 3- to 6-inch crystals, a horizontal polarization method using a glue-mixed crystal powder is generally still used. However, for crystals larger than 8 inches, horizontal polarization easily causes the crystal to tilt, posing a very high risk. Some patented technologies propose using high-purity niobium oxide to make crucibles, with a vertical electric field laterally polarizing the X-axis lithium niobate crystal. However, niobium oxide crucibles are expensive to manufacture, and niobium oxide can cause Li diffusion, resulting in uneven crystal composition. Utility Model Content

[0003] This invention addresses the shortcomings of existing technologies by providing a device for single-domain conversion of large-size lithium niobate crystals.

[0004] This utility model is achieved through the following technical solution: a device for single-domain application of large-size lithium niobate crystals is provided, including a lower electrode plate, an upper electrode sheet, and an annular lithium niobate ring block. The lower end of the lithium niobate ring block is placed on the lower electrode plate, and the lithium niobate ring block is filled with lithium niobate powder. The lithium niobate crystal is embedded in the lithium niobate powder, and the upper electrode sheet covers the lithium niobate powder.

[0005] The lithium niobate rings in this solution are formed by mixing lithium niobate powder with adhesive, followed by long-term curing and sintering. The crystals are then placed within the rings for polarization. This method is simple and convenient, avoiding the problems of traditional powder cap manufacturing, such as easy detachment and warping leading to incomplete polarization. It also avoids the high cost and outsourcing requirements of niobium oxide pots, and the issue of Li diffusion caused by niobium oxide pots.

[0006] As an optimization, a ceramic plate is placed above the upper electrode sheet.

[0007] As an optimization, the lower electrode plate is disc-shaped.

[0008] As an optimization, a support frame located within the lithium niobate ring block is also included. The support frame includes two support rings arranged vertically and connected by a connecting rod. Multiple mounting blocks are fixed to the support rings circumferentially. It also includes inner support rods and outer support rods arranged circumferentially on the mounting blocks. The inner support rods are threaded to the inner side of the mounting blocks, and the outer support rods are threaded to the outer side of the mounting blocks.

[0009] As an optimization, the support frame also includes a central block located above the support ring, the central block being connected to the support ring above via a hanger, and a handle being fixedly attached to the central block.

[0010] As an optimization, six mounting blocks are fixedly connected to the support ring circumferentially.

[0011] The beneficial effects of this invention are as follows: This invention provides a device for single-domain polarization of large-size lithium niobate crystals. The lithium niobate ring is formed by mixing lithium niobate powder with adhesive, followed by long-term curing and sintering. The crystal is placed into the ring for polarization. This method is simple and convenient, avoiding the problems of traditional powder cap manufacturing, such as easy detachment and warping leading to incomplete polarization, as well as the high cost and outsourcing of niobium oxide pots, and the potential for Li diffusion caused by niobium oxide pots. The polarization process does not require adhesive, ensuring sufficient polarization and saving on adhesive usage and costs. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the internal structure of this utility model;

[0013] Figure 2 This is a schematic diagram of the internal structure of the support frame used in this utility model;

[0014] Figure 3 This is a schematic diagram of the support frame of this utility model;

[0015] Figure 4 This is a front view of the support frame of this utility model;

[0016] Figure 5 This is a top view of the support frame of this utility model;

[0017] As shown in the figure:

[0018] 1. Lithium niobate ring block, 2. Lower electrode plate, 3. Upper electrode sheet, 4. Lithium niobate crystal, 5. Support frame, 51. Support ring, 52. Mounting block, 53. Outer support rod, 54. Inner support rod, 55. Connecting rod, 56. Hanging rod, 57. Center block, 58. Handle. Detailed Implementation

[0019] To clearly illustrate the technical features of this solution, the following detailed implementation method will be used to explain the solution.

[0020] like Figures 1-5 As shown, this utility model discloses a device for single-domain formation of large-size lithium niobate crystals, including a lower electrode plate 2, an upper electrode sheet 3, and an annular lithium niobate ring block 1. The lithium niobate ring block 1 is made of lithium niobate material. The preparation process of the lithium niobate ring block 1 involves mixing ultrafine lithium niobate polycrystalline powder with glue, solidifying it into shape with a mold, and then drying it for more than one month. After drying, it is fired at 1240°C, at which point a lithium niobate ring block with a certain strength can be produced.

[0021] Both the lower electrode plate 2 and the upper electrode sheet 3 are platinum sheets, and electrode wires are connected to both. The lower electrode plate 2 is disc-shaped to prevent lithium niobate powder from spilling from the edges.

[0022] The lower end of the lithium niobate ring 1 is placed on the lower electrode plate 2. The lithium niobate ring 1 is filled with lithium niobate powder, and lithium niobate crystals 4 are embedded in the lithium niobate powder. The upper electrode plate 3 covers the lithium niobate powder. A ceramic plate is placed on top of the upper electrode plate 3 to provide a pressing effect, and the electrode wire of the upper electrode plate 3 passes through the central hole of the ceramic plate.

[0023] In use, first place a lower electrode plate 2 underneath, then place the prepared lithium niobate ring 1 on the lower electrode plate 2, sprinkle lithium niobate powder into it, and then place a lithium niobate crystal in and compact it (ensuring the crystal does not touch the bottom). At this time, to prevent the lithium niobate crystal from moving, a support frame 5 needs to be placed. Subsequently, pour in lithium niobate powder (calcined at 1240℃) 2cm above the crystal head. After the lithium niobate crystal is completely buried in the lithium niobate powder, remove the support frame 5, then place the upper electrode plate 3, press it on the upper electrode plate 3 with a ceramic plate, and lead out the electrode wire from the upper hole.

[0024] The support frame 5 is made of plastic injection molding. The support frame 5 includes two support rings 51 arranged vertically. The diameter of the support ring 51 is larger than the outer diameter of the lithium niobate crystal 4 and smaller than the inner diameter of the lithium niobate ring block 1.

[0025] Multiple mounting blocks 52 are fixedly connected to the upper circumferential edge of the support ring 51. In this embodiment, six mounting blocks 52 are fixedly connected to the upper circumferential edge of the support ring 51 and are evenly distributed circumferentially. The two support rings 51 are connected by connecting rods 55. There are three connecting rods 55, and their two ends are fixedly connected to the mounting blocks 52 of the upper and lower support rings 51 respectively, thereby connecting the two support rings 51 into one unit.

[0026] The inner support rods 54 and outer support rods 53 are also arranged circumferentially on the mounting block 52. In this embodiment, there are six mounting blocks on each support ring 51, so three inner support rods 54 and three outer support rods 53 are installed on each support ring 51.

[0027] The inner support rod 54 is threaded to the inside of the mounting block 52. Its position can be adjusted by rotating the inner support rod 54. A total of six inner support rods 54, through two support rings 51, surround the outside of the lithium niobate crystal 4, which plays a positioning role.

[0028] The outer support rod 53 is threaded to the outside of the mounting block 52. The position of the outer support rod 53 can be adjusted by rotating it. The six outer support rods 53, which are connected to the inner ring of the lithium niobate ring block 1 through the two support rings 51, play a positioning role for the support frame 5.

[0029] To facilitate the lifting of the support frame 5, the support frame 5 also includes a central block 57 located above the support ring 51. The central block 57 is connected to the support ring 51 above via a scalloped rod 56. A handle 58 is fixed to the central block 57 to facilitate lifting the entire support frame 5.

[0030] Of course, the above description is not limited to the examples above. Technical features of this utility model not described can be implemented by or using existing technology, and will not be repeated here. The above embodiments and drawings are only used to illustrate the technical solution of this utility model and are not intended to limit this utility model. This utility model has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that any changes, modifications, additions or substitutions made by those skilled in the art within the scope of this utility model do not depart from the spirit of this utility model and should also fall within the protection scope of the claims of this utility model.

Claims

1. A device for single-domain formation of large-size lithium niobate crystals, characterized in that: It includes a lower electrode plate (2), an upper electrode sheet (3), and an annular lithium niobate ring block (1). The lower end of the lithium niobate ring block (1) is placed on the lower electrode plate (2). The lithium niobate ring block (1) is filled with lithium niobate powder, and lithium niobate crystals (4) are embedded in the lithium niobate powder. The upper electrode sheet (3) covers the lithium niobate powder.

2. The apparatus for single-domain formation of large-size lithium niobate crystals according to claim 1, characterized in that: A ceramic plate is placed on top of the upper electrode sheet (3).

3. The apparatus for single-domain formation of large-size lithium niobate crystals according to claim 1, characterized in that: The lower electrode plate (2) is disc-shaped.

4. The apparatus for single-domain formation of large-size lithium niobate crystals according to claim 1, characterized in that: It also includes a support frame (5) located inside the lithium niobate ring block (1). The support frame (5) includes two support rings (51) arranged vertically. The two support rings (51) are connected by a connecting rod (55). Multiple mounting blocks (52) are fixedly connected to the support rings (51) along the circumferential direction. It also includes an inner support rod (54) and an outer support rod (53) arranged circumferentially on the mounting blocks (52). The inner support rod (54) is threaded to the inner side of the mounting block (52), and the outer support rod (53) is threaded to the outer side of the mounting block (52).

5. The apparatus for single-domain formation of large-size lithium niobate crystals according to claim 4, characterized in that: The support frame (5) also includes a central block (57) located above the support ring (51), the central block (57) being connected to the support ring (51) above via a hanger (56), and a handle (58) being fixedly attached to the central block (57).

6. The apparatus for single-domain formation of large-size lithium niobate crystals according to claim 4, characterized in that: The support ring (51) has six mounting blocks (52) fixedly connected to it circumferentially.

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