CN109579812B - Method for manufacturing high-regularity atomic gas chamber - Google Patents

Abstract

The invention belongs to optical precision processing technology, and relates to a manufacturing method of a high-regularity atomic gas chamber. The manufacturing method of the high-regularity atomic gas chamber of the present invention uses low-temperature bonding technology to sequentially bond the pre-processed gas chamber bracket and the optical window at room temperature, and processes the heating surface of the atomic gas chamber and the flushing and exhaust nozzle to form a high Regularity air chamber. Compared with the existing atomic gas chamber manufacturing method, the regularity of the gas chamber is greatly improved, the errors caused by the irregular shape of the gas chamber are reduced, and the laser wavefront distortion is reduced at the same time. It has high processing accuracy, good symmetry, and good surface quality. The advantages.

Description

A method for manufacturing a high-regularity atomic gas chamber

technical field

The invention belongs to optical precision processing technology, and relates to a manufacturing method of a high-regularity atomic gas chamber.

Background technique

As an angular rate sensitive unit, the atomic gas chamber is the core component of the nuclear magnetic resonance gyroscope. The gyro completes the preparation, manipulation and signal detection of working atoms in the atomic gas chamber. The performance of the atomic gas chamber determines the performance of the gyroscope from the source.

Conventional atomic gas chamber manufacturing usually adopts glass blowing, laser welding or welding processes. These technologies involve overall or local high temperature, and the gas chamber is formed or sealed through high-temperature deformation of glass, which will cause irregular contours inside and outside the gas chamber (the structural size error exceeds 0.3mm), high-temperature deformation in the local area (especially the four corners of the gas chamber), poor surface quality of the gas chamber window (surface shape is generally greater than λ/2), resulting in low installation accuracy of the gas chamber, beam wavefront distortion, etc. Errors, especially the irregularity of the gas chamber, will cause the inherent magnetic field generated by the polarized atoms in the gas chamber to be unable to completely cancel, causing the magnetic resonance line to broaden, and will also limit the polarization of the alkali metal or even the final polarization of the inert gas. ways to improve.

Contents of the invention

The purpose of the present invention is to provide a method for manufacturing a high-regularity atomic gas chamber, which can greatly improve the regularity of the gas chamber, reduce various errors caused by the irregular shape of the gas chamber, and reduce laser wavefront distortion.

The technical solution of the present invention: a method for manufacturing a high-regularity atomic gas chamber. At room temperature, the previously processed gas chamber bracket and the optical window are sequentially bonded by using low-temperature bonding technology, and the heating surface and the punching surface of the atomic gas chamber are processed. Exhaust nozzle.

The manufacturing method of the described high-regularity atomic gas chamber, its specific steps are as follows:

Step 1: Workpiece Preparation

Check that all the working surfaces of the first optical window 1, the second optical window 2, the first support 3 and the second support 4 meet the low-temperature bonding requirements;

Step 2: Bond the first support 3 and the second support 4

Low-temperature bonding the bottom surfaces of the first support 3 and the second support 4 to the first optical window 1;

Step 3: Polish the first bonding surface 5

Polishing the first bonding surface 5 of the first bracket 3 and the second bracket 4 to meet the bonding requirements;

Step 4: Bonding the First Optical Window 1

bonding the first optical window 1 to the first bonding surface 5 at low temperature;

Step 5: Polish the second bonding surface 6

Polishing the first bracket 3 and the second bracket 4 and the second bonding surface 6 on the side of the first optical window 1 to meet the bonding requirements;

Step 6: Bonding the Second Optical Window 2

bonding the second optical window 3 to the second bonding surface 6 at low temperature;

Step 7: Polish the third bonding surface 7

Polishing the first bracket 3 and the second bracket 4 and the third bonding surface 7 on the other side of the first optical window 1 meet the bonding requirements;

Step 8: Bonding the Second Optical Window 2

bonding the second optical window 2 to the third bonding surface 7 at low temperature;

Step 9: Curing

Curing the bonded workpiece;

Step 10: Exterior Finishing

Polish the outside of the workpiece to improve the dimensional accuracy, and coat the window to increase the transmittance;

Step 11: Thinning

Thinning the side of the workpiece including the first optical window 1, the second optical window 2, and the first bracket 3 to form a gas chamber heating surface 8;

Step 12: Milling

Milling is performed on one side of the workpiece including the first optical window 1 , the second optical window 2 , and the second bracket 4 to form an air chamber inflation and exhaust surface 9 .

The high-regularity atomic gas chamber is a high-regularity cuboid structure, which contains a high-regularity cuboid cavity.

The first optical window 1 is rectangular and consists of 2 pieces, the width of which is consistent with the width of the cuboid cavity.

The second optical window 2 is rectangular, and there are two pieces in total, and its width is consistent with the outer contour width of the gas chamber.

The first bracket 3 is a rectangular parallelepiped, its width is equal to that of the first optical window 1, and its height is equal to the height of the rectangular parallelepiped cavity.

The second bracket 4 is a cuboid structure, the outer contour is exactly the same as that of the first bracket 3 , and a through hole 10 is arranged in the center thereof.

The distance between the first bracket 3 and the second bracket 4 is the three-dimensional length of the cuboid cavity.

The first bonding surface 5 is composed of the top surfaces of the first bracket 3 and the second bracket 4 .

The second bonding surface 6 and the third bonding surface 7 are respectively composed of the first support 3 , the second support 4 and the two sides of the first optical window 1 .

The advantages and beneficial effects of the present invention are: providing a method for manufacturing a high-regularity atomic gas chamber, greatly improving the regularity of the gas chamber, reducing the magnetic field error caused by the irregular shape of the gas chamber, and reducing the laser wavefront at the same time distortion. In an embodiment of the present invention, it is proved by experiments that the size error of the air chamber is better than 0.01 mm, the surface shape of the air chamber window is better than λ/20, and the size regularity of the air chamber shape is at least an order of magnitude higher than that of the traditional method.

Description of drawings

Fig. 1 is a schematic view (exploded view) of the method for manufacturing a high-regularity atomic gas cell of the present invention.

Fig. 2 is a schematic diagram of step 2 of the method for manufacturing a high-regularity atomic gas cell of the present invention.

Fig. 3 is a schematic diagram of step 4 of the method for manufacturing a high-regularity atomic gas cell of the present invention.

Fig. 4 is a schematic diagram of step 6 of the manufacturing method of the high-regularity atomic gas cell of the present invention.

Fig. 5 is a schematic diagram of Step 8 of the manufacturing method of the high-regularity atomic gas cell of the present invention.

Fig. 6 is a schematic diagram of Step 11 of the method for manufacturing a high-regularity atomic gas cell of the present invention.

Fig. 7 is a schematic diagram of Step 12 of the manufacturing method of the high-regularity atomic gas cell of the present invention.

detailed description

The present invention will be described in further detail below.

Please refer to FIG. 1 , wherein FIG. 1 is a schematic diagram (exploded view) of the method for manufacturing a high-regularity atomic gas cell of the present invention. The invention utilizes the characteristics of high precision, high strength, low stress, and high sealing of the low-temperature bonding technology to bond six precision optical elements and then form a high-regularity gas chamber through further processing. The air chamber is a high regularity cuboid structure, which contains a high regularity cuboid cavity for containing working gas.

The six pieces of precision optical components include: two pieces of the first optical window 1 and two pieces of the second optical window 2, one piece of the first bracket 3, and one piece of the second bracket 4. The first optical window 1 is a cuboid, and its width is consistent with the three-dimensional width of the cuboid cavity of the atomic gas cell. The second optical window 2 is a cuboid whose width is consistent with the width of the outer contour of the gas chamber, approximately equal to the sum of the thickness of the two first optical windows 1 and the height of the first bracket 3 . The first support 3 is a cuboid, its width is equal to that of the first optical window 1 , and its height is consistent with the three-dimensional height of the cavity of the cuboid. The second bracket 3 is a cuboid with the same outer contour as the first bracket 3 , and a through hole 10 is arranged in the center thereof for inflating and exhausting the air chamber.

Its specific process steps are as follows:

Step 1: Workpiece Preparation

Check that the working surfaces of the first optical window 1, the second optical window 2, the first bracket 3, and the second bracket 4 meet the low-temperature bonding requirements, that is, the surface shape is at least better than λ/4, and usually requires to reach λ/10 ; Check the surface for at least level 2 flaws and no penetrating scratches to prevent the air chamber from being affected. All components must be ultra-precision cleaned to remove surface particles and contaminants, and surface treated to improve bonding efficiency.

Step 2: Bond the first support 3 and the second support 4

Please refer to FIG. 2 at the same time, wherein FIG. 2 is a schematic diagram of step 2 of the method for manufacturing a high-regularity atomic gas cell of the present invention. The bottom surfaces of the first bracket 3 and the second bracket 4 are cryogenically bonded to the first optical window 1, and limit tooling can be used to ensure the installation accuracy and ensure the alignment between the first bracket 3, the second bracket 4 and the first optical window 1. Both sides are aligned to reduce the workload of the subsequent polishing process and facilitate the control of dimensional accuracy. The distance between the first bracket 3 and the second bracket 4 is the three-dimensional length of the cuboid cavity of the air chamber.

Step 3: Polish the first bonding surface 5

Observing under the laser interferometer, it can be found that even if the outline dimensions of the first bracket 3 and the second bracket 4 are exactly the same, the first bonding surface 5 composed of the top surfaces of the first bracket 3 and the second bracket 4 still exists after step 2 There is a slight height difference, so it needs to be polished until it meets the bonding requirements and improves the regularity.

Step 4: Bonding the First Optical Window 1

Please also refer to FIG. 3 , wherein FIG. 3 is a schematic diagram of Step 4 of the method for manufacturing a high-regularity atomic gas cell of the present invention. The first optical window 1 is cryogenically bonded to the first bonding surface 5 , and a limit tool is used to ensure installation accuracy and to ensure that the two first optical windows 1 are completely aligned.

Step 5: Polish the second bonding surface 6

The second bonding surface 6 is composed of the same side of the first support 3 , the second support 4 and the first optical window 1 . Polish the surface to meet the bonding requirements to improve regularity.

Step 6: Bonding the Second Optical Window 2

Please also refer to FIG. 4 , wherein FIG. 4 is a schematic diagram of Step 6 of the method for manufacturing a high-regularity atomic gas cell of the present invention. The second optical window 3 is bonded to the second bonding surface 6 at a low temperature, and a limit tool is used to ensure installation accuracy.

Step 7: Polish the third bonding surface 7

The third bonding surface 7 is composed of the first bracket 3 , the second bracket 4 and the other side of the first optical window 1 . The third bonding surface 7 is polished to meet the bonding requirements, so as to improve regularity.

Step 8: Bonding the Second Optical Window 2

Please refer to FIG. 5 at the same time, wherein FIG. 5 is a schematic diagram of Step 8 of the method for manufacturing a high-regularity atomic gas cell according to the present invention. The second optical window 2 is cryogenically bonded to the third bonding surface 7, and a limit tool is used to ensure installation accuracy and ensure that the two second optical windows 2 are completely aligned.

Step 9: Curing

The bonded workpieces are cured, and the curing process can be carried out by standing at room temperature, or by drying, low-pressure treatment, heat treatment and other accelerated drying methods.

Step 10: Exterior Finishing

The outer surface of the workpiece is polished to improve the dimensional accuracy of the outer contour; the window part is coated to increase the beam transmittance.

Step 11: Thinning

Please also refer to FIG. 6 , wherein FIG. 6 is a schematic diagram of Step 11 of the method for manufacturing a high-regularity atomic gas cell of the present invention. Use optical molding equipment to thin the side of the workpiece including the first optical window 1, the second optical window 2, and the first bracket 3, and cut off excess parts to form the air chamber heating surface 8, which is convenient for heat conduction.

Step 12: Milling

Please also refer to FIG. 7 , wherein FIG. 7 is a schematic diagram of step 12 of the method for manufacturing a high-regularity atomic gas cell of the present invention. The optical forming equipment is used to mill the side of the workpiece including the first optical window 1 , the second optical window 2 and the second bracket 4 to form an air chamber inflation and exhaust surface 9 . The air chamber inflation and exhaust surface 9 is provided with an inflation and exhaust pipe, which is used for air chamber inflation and exhaust.

Implementation case

The sample material is quartz glass, the size of the first optical window is 67×11×2mm ³ , the size of the second optical window is 67×15×2mm ³ , the size of the first bracket is 28×11×11mm ³ , and the size of the second bracket is 28×11×11mm ³ , all working surfaces are polished to λ/10. The center of the second support 4 has a hole of φ2mm. Samples were washed with various solutions. First, the samples were ultrasonically cleaned in isopropanol for 10 min, immersed in a cleaning solution (H ₂ SO ₄ (96%):K ₂ Cr ₂ O ₇ : 5:1) for 30 min, and then in KOH solution for 5 min. The samples were rinsed under deionized water for 5 min, and finally dried with nitrogen. Clean samples are placed in a clean, dust-free container until bonding.

Follow steps 2-8 to assemble in sequence. The bonding solution for low-temperature bonding is 0.5% KOH aqueous solution, and the bonding solution is applied to the bonding interface, and then the two surfaces to be bonded are brought into contact and gently squeezed. After bonding, the workpiece should be cured at room temperature for at least 7 days or heat treated in the range of 60-120°C.

The outer surface of the workpiece is ground and polished to ensure that the outer dimension is 67×15×15mm ³ . Anti-reflective coating is applied to the window to increase the beam transmittance.

Use an internal circle cutting machine to thin the workpiece to 2 mm on one side including the first optical window, the second optical window, and the first bracket.

Use a five-axis machining center to mill the side of the workpiece including the first optical window 1, the second optical window 2, and the second bracket 4. The outer diameter of the central exhaust pipe is 4mm, the inner diameter is 2mm, and the thickness of the surface where the exhaust pipe is located is 2mm. Same as other faces.

Finally, a cube air chamber is formed, the side length of the outer contour is 15 mm, and the side length of the inner cavity is 11 mm.

Implementation Effect

The manufacturing method of the high-regularity atomic gas chamber of the present invention utilizes the high-precision, high-strength, and low-stress characteristics of the low-temperature bonding technology to form a high-regularity gas chamber through strict design and control of the low-temperature bonding sequence and process of six precision optical elements. The chamber has the advantages of high processing precision, good symmetry, and good surface quality. The formed atomic gas chamber has a dimensional error of better than 0.01mm, no distortion in the structure, and the shape of the gas chamber window is better than λ/20. Compared with the existing manufacturing methods of atomic gas chambers, such as laser welding method and glass blowing method, the regularity of the shape and surface size of the gas chamber is at least one order of magnitude higher than that of traditional processes.

Claims (9)

1. A method for manufacturing a high-regularity atomic gas chamber, characterized in that, at room temperature, the gas chamber bracket processed in advance is bonded with the optical window sequentially by using low-temperature bonding technology, and the heating surface of the atomic gas chamber and the punching surface are processed. Exhaust nozzle, the specific steps are as follows: Step 1: Workpiece Preparation Check that all working surfaces of the first optical window (1), the second optical window (2), the first support (3) and the second support (4) meet the requirements for low-temperature bonding; Step 2: Bond the first bracket (3), the second bracket (4) low-temperature bonding the bottom surfaces of the first bracket (3) and the second bracket (4) to the first optical window (1); Step 3: Polish the first bonding surface (5) Polishing the first bonding surface (5) of the first bracket (3) and the second bracket (4) to meet the bonding requirements; Step 4: Bond the first optical window (1) bonding the first optical window (1) to the first bonding surface (5) at a low temperature; Step 5: Polish the second bonding surface (6) Polishing the first bracket (3) and the second bracket (4) and the second bonding surface (6) on the side of the first optical window (1) to meet the bonding requirements; Step 6: Bond the Second Optical Window (2) bonding the second optical window (2) to the second bonding surface (6) at low temperature; Step 7: Polish the third bonding surface (7) Polishing the first bracket (3) and the second bracket (4) and the third bonding surface (7) on the other side of the first optical window (1) meet the bonding requirements; Step 8: Bond the Second Optical Window (2) bonding the second optical window (2) to the third bonding surface (7) at low temperature; Step 9: Curing Curing the bonded workpiece; Step 10: Exterior Finishing Polish the outside of the workpiece to improve the dimensional accuracy, and coat the window to increase the transmittance; Step 11: Thinning Thinning one side of the workpiece including the first optical window (1), the second optical window (2) and the first support (3) to form a gas chamber heating surface (8); Step 12: Milling Milling is performed on one side of the workpiece including the first optical window (1), the second optical window (2) and the second bracket (4), to form an air chamber inflation and exhaust surface (9). 2. The manufacturing method of a high-regularity atomic gas cell according to claim 1, wherein the high-regularity atomic gas cell is a high-regularity cuboid structure, which contains a high-regularity cuboid cavity. 3. The manufacturing method of a high-regularity atomic gas cell according to claim 2, characterized in that, the first optical window (1) is a rectangle, a total of 2 pieces, and its width is consistent with the width of the cuboid cavity. 4. The manufacturing method of a high-regularity atomic gas cell according to claim 2, characterized in that, the second optical window (2) is a rectangle, a total of 2 pieces, and its width is consistent with the outer contour width of the gas cell. 5. a kind of high regularity atomic gas chamber manufacturing method according to claim 2 is characterized in that, described first support (3) is cuboid structure, and its width is equal to the first optical window (1), and its height Consistent with the height of the cavity of the cuboid. 6. A kind of high-regularity atomic gas chamber manufacturing method according to claim 2, is characterized in that, described second support (4) is cuboid structure, and outer profile is identical with first support (3), and its center Through holes (10) are provided. 7. The manufacturing method of a high-regularity atomic gas chamber according to claim 2, characterized in that the distance between the first support (3) and the second support (4) is the three-dimensional length of a cuboid cavity. 8. A method for manufacturing a high-regularity atomic gas chamber according to claim 2, characterized in that, the first bonding surface (5) is formed by the top of the first support (3) and the second support (4). surface composition. 9. a kind of high-regularity atomic gas cell manufacturing method according to claim 2, is characterized in that, described second bonding surface (6), the 3rd bonding surface (7) are respectively made of first support (3) ), the second bracket (4) and the two sides of the first optical window (1).

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