Polarization device for large-size lithium niobate crystal

Abstract

The utility model discloses a large-size lithium niobate crystal polarization device, which comprises a polarization furnace and a high-temperature-resistant crucible, a negative platinum sheet and a positive platinum sheet are respectively arranged at the bottom and the top of the high-temperature-resistant crucible, the interior of the high-temperature-resistant crucible is used for loading a lithium niobate crystal, and lithium niobate crystal crushed aggregates are respectively laid above and below the lithium niobate crystal; and the negative platinum sheet and the positive platinum sheet are respectively connected to a direct-current power supply outside the furnace through platinum wires. During use, the polarization furnace is heated to a set temperature, a direct-current power supply is turned on, pressurized polarization is performed, after polarization is completed, the temperature is reduced to room temperature, and crystals are taken out. The crystals and the platinum sheet are filled with lithium niobate crystal crushed aggregates, so that polarization current is effectively ensured to pass through the inside of the crystals, and the device is suitable for lithium niobate crystals with different shapes and sizes; the crushed lithium niobate crystals can effectively prevent the lithium niobate crystals from being broken down by polarization current, the stability of the crystal structures is ensured, and the crystals are prevented from cracking, so that the polarization yield is improved.

Description

Technical Field

[0001] The utility model belongs to the field of lithium niobate polarization, and in particular relates to a polarization device for a large-size lithium niobate crystal. Background Art

[0002] Lithium niobate (LiNb0 3 ) crystal is a crystal material that integrates multifunctional effects such as electro-optic, acousto-optic, photorefractive and laser effects, and has been widely used in many fields. In recent years, the research on lithium niobate crystals has mainly focused on large size, uniformity and ion doping. The polarization of lithium niobate crystals, as a post-crystal growth treatment process, plays a key role in the subsequent application of lithium niobate crystals.

[0003] At present, with the increasing demand for surface acoustic wave devices, the crystal end is also developing towards larger size. As the size increases, the methods used in the existing technology often have problems such as incomplete polarization and poor single domain effect. Summary of the invention

[0004] Purpose of the utility model: The technical problem to be solved by the utility model is to provide a polarization device for large-sized lithium niobate crystals in view of the shortcomings of the prior art, thereby improving the convenience and effect of polarization of lithium niobate crystals and saving working time.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0006] A polarization device for large-sized lithium niobate crystals includes a polarization furnace and a high-temperature resistant crucible. The bottom and top of the high-temperature resistant crucible are respectively provided with a negative platinum sheet and a positive platinum sheet. The interior of the high-temperature resistant crucible is used to load lithium niobate crystals. Lithium niobate crystal fragments are laid on the top and bottom of the lithium niobate crystals. The negative platinum sheet and the positive platinum sheet are respectively connected to a DC power supply outside the furnace through platinum wires. When in use, the polarization furnace is heated to a set temperature, the DC power supply is turned on, and pressure polarization is applied. After polarization is completed, it is cooled to room temperature and the crystal is taken out.

[0007] Furthermore, a heat-insulating brick is arranged above the platinum sheet, and the platinum sheet is pressed onto the top opening of the high-temperature resistant crucible through the heat-insulating brick.

[0008] Further preferably, the upper and lower parts and surrounding areas of the lithium niobate crystal are covered with lithium niobate crystal fragments.

[0009] Preferably, the size of the lithium niobate crystal is 2-8 inches.

[0010] Preferably, the lithium niobate crystal fragments are fragments made by rolling and grinding lithium niobate crystals, and the particle size of the fragments is 1 mm-3 mm.

[0011] Specifically, the polarization furnace is heated by silicon-molybdenum rods or silicon-carbon rods.

[0012] Preferably, the negative platinum sheet and the positive platinum sheet are circular in shape with a diameter of 3-20 cm.

[0013] Preferably, the high temperature resistant crucible is made of alumina, zirconia or quartz. Beneficial Effects

[0014] (1) The utility model effectively ensures that the polarization current passes through the interior of the crystal by filling the crystal and the platinum sheet with lithium niobate crystal fragments, and is suitable for use with lithium niobate crystals of different shapes and sizes;

[0015] (2) The lithium niobate crystal fragments in the utility model can effectively prevent the lithium niobate crystal from being broken down by the polarization current, ensure the stability of the crystal structure, avoid crystal cracking, and thus improve the polarization yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation methods, and the above and / or other advantages of the present invention will become more clear.

[0017] Figure 1 It is a structural schematic diagram of the device of the utility model.

[0018] Figure 2 This is a diagram of the domain structure of a lithium niobate wafer after being polarized using the present device.

[0019] Wherein, each reference numeral represents:

[0020] Polarization furnace 1, high temperature resistant crucible 2, negative platinum sheet 3, lithium niobate crystal fragments 4, lithium niobate crystal 5, positive platinum sheet 6, insulation brick 7, platinum wire 8, DC power supply 9. DETAILED DESCRIPTION

[0021] The present invention can be better understood according to the following embodiments.

[0022] The structures, proportions, sizes, etc. illustrated in the drawings of the specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the utility model, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effect and purpose that can be achieved by the utility model, should still fall within the scope of the technical content disclosed by the utility model. At the same time, the terms such as "upper", "lower", "front", "back", "middle" and so on quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the utility model. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the utility model without substantial change of the technical content.

[0023] like Figure 1 and Figure 2 As shown, the polarization device of the large-size lithium niobate crystal of the utility model comprises a polarization furnace 1, a high temperature resistant crucible 2, a negative platinum sheet 3 and a positive platinum sheet 6 are respectively arranged at the bottom and the top of the high temperature resistant crucible 2, the interior of the high temperature resistant crucible 2 is used to load the lithium niobate crystal 5, and lithium niobate crystal fragments 4 are respectively laid on the upper and lower parts of the lithium niobate crystal 5; the negative platinum sheet 3 and the positive platinum sheet 6 are respectively connected to the DC power supply 9 outside the furnace through the platinum wire 8. When in use, the polarization furnace is heated to the set temperature, the DC power supply is turned on, and the pressure is applied for polarization. After the polarization is completed, it is cooled to room temperature and the crystal is taken out.

[0024] A heat preservation brick 7 is arranged above the positive platinum sheet 6 , and the positive platinum sheet 6 is pressed onto the top opening of the high temperature resistant crucible 2 through the heat preservation brick 7 .

[0025] The upper and lower parts and surrounding areas of the lithium niobate crystal 5 are all covered with lithium niobate crystal fragments 4 .

[0026] The size of the lithium niobate crystal 5 is 6 inches.

[0027] The lithium niobate crystal fragments 4 are fragments made by rolling and grinding lithium niobate crystals, and the particle size of the fragments is 1 mm to 3 mm.

[0028] The polarization furnace 1 is heated by silicon-molybdenum rods or silicon-carbon rods.

[0029] The negative platinum sheet 3 and the positive platinum sheet 6 are circular in shape, with a diameter of 3-20 cm.

[0030] The material of the high temperature resistant crucible 2 is alumina, zirconia or quartz.

[0031] The polarization process of lithium niobate crystal is as follows: 1. Check whether all parts of the instrument are operating normally; 2. Place the platinum electrode at the bottom of the alumina crucible, and connect the platinum wire to the edge of the platinum sheet as a conductor; 3. Spread the lithium niobate crystal fragments on the platinum electrode, put the 6-inch lithium niobate crystal into the alumina crucible, fill the gap in the remaining part of the alumina crucible, flatten it, add the platinum sheet, and press it with insulation bricks; 4. Heat up. Heat to 1160 ℃ at a rate of 60 ℃ / h, keep warm for 20 hours, apply voltage, slowly apply voltage from 0 V to the appropriate value, and keep it constant for 2 hours; 5. Cool down to room temperature at a rate of 30 ℃ / h to complete the polarization. 6. Slice the polarized crystal for corrosion test to obtain the corrosion pits of the chip. The corrosion pits are relatively uniform, indicating that the polarization effect is good.

[0032] The utility model provides a concept and method for a polarization device of a large-sized lithium niobate crystal. There are many methods and ways to implement the technical solution. The above is only a preferred implementation of the utility model. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the utility model. These improvements and modifications should also be regarded as the protection scope of the utility model. All components not specified in this embodiment can be implemented by existing technologies.

Claims

1. A polarization device for a large-sized lithium niobate crystal, characterized in that: It comprises a polarization furnace (1), a high temperature resistant crucible (2), wherein a negative platinum sheet (3) and a positive platinum sheet (6) are respectively arranged at the bottom and the top of the high temperature resistant crucible (2), and the interior of the high temperature resistant crucible (2) is used to load lithium niobate crystals (5), and lithium niobate crystal fragments (4) are respectively laid on the top and bottom of the lithium niobate crystals (5); the negative platinum sheet (3) and the positive platinum sheet (6) are respectively connected to a direct current power supply (9) outside the furnace through a platinum wire (8); A heat-insulating brick (7) is arranged above the platinum sheet (6), and the platinum sheet (6) is pressed onto the top opening of the high-temperature resistant crucible (2) through the heat-insulating brick (7); The upper and lower parts and surrounding areas of the lithium niobate crystal (5) are covered with lithium niobate crystal fragments (4); The size of the lithium niobate crystal (5) is 6 inches; The lithium niobate crystal fragments (4) are obtained by rolling and grinding lithium niobate crystals, and the particle size of the fragments is 1 mm to 3 mm. The polarization furnace (1) is heated by silicon-molybdenum rods or silicon-carbon rods; The negative platinum sheet (3) and the positive platinum sheet (6) are circular in shape, with a diameter of 3-20 cm; The high temperature resistant crucible (2) is made of alumina, zirconia or quartz.

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