Dry-type ultra-low-vibration optical measuring device

Abstract

The application provides a dry type ultra-low vibration optical measuring device, which comprises a main cavity part and a refrigeration part, the refrigeration part comprises a vacuum cavity and a refrigeration machine main body, the refrigeration machine main body is composed of a low-temperature refrigeration machine, a lower damping bellows and an upper damping bellows; a first-stage cold head of the low-temperature refrigeration machine is connected with a first-stage cold head cold screen, a second-stage cold head cools a main cavity sample cold plate through a second transverse cold heat bridge and a second-stage cold head heat-conducting copper braid, and the first-stage cold head cold screen cools a sample area cold screen through a first transverse cold heat bridge and a first-stage cold head heat-conducting copper braid; vertical direction damping is realized through the lower damping bellows, the upper damping bellows, a spring and a fluorine rubber damping combination structure, horizontal direction damping is realized through a first transverse bellows and a second transverse bellows, and the lower damping bellows and the upper damping bellows are communicated through a flexible connecting pipe to balance the internal pressure of the two bellows; the optical device has the characteristics of high-efficiency refrigeration and ultra-low vibration, and meets the demand of high-precision optical measurement.

Description

Technical Field

[0001] This invention relates to the field of optical measurement, more specifically to an optical measurement device using cryogenic refrigeration technology, and even further to a dry ultra-low vibration optical measurement device. Background Technology

[0002] With the continuous advancement and development of science and technology, cryogenic technology, optical technology, and strong magnetic field and low vibration technology have become indispensable auxiliary techniques in many scientific experimental fields such as physics, chemistry, materials science, quantum physics, and superconductivity. These experiments require the construction of an optical measurement device. Optical measurement devices are highly sensitive tools that utilize the magneto-optical effect to study the magnetic and optical properties of materials, and are widely used in materials science, biomedicine, and information technology. An optical measurement device typically consists of a light source, a magnetic field generator, a detector, and a data acquisition and analysis system.

[0003] Cryogenic refrigeration systems play a crucial role in optical measurement devices. They primarily provide the following support: (1) cooling samples to low temperatures (such as liquid helium or liquid nitrogen) to study the magnetic and optical properties of materials at low temperatures; (2) providing a stable low-temperature environment, reducing thermal noise interference with measurements, ensuring precise and controllable experimental conditions, and obtaining high-precision optical data at low temperatures; and (3) supporting research on phase transition behavior of materials at low temperatures, such as superconductivity or magnetic phase transitions, expanding the research scope of optical measurement devices, and enabling them to explore more low-temperature physical phenomena.

[0004] Cooling methods for optical measurement devices can be broadly categorized into two types: The first type utilizes refrigerants for cooling. These devices typically store liquid helium in specialized containers or continuously deliver liquid helium to the experimental area requiring cooling via a piping system. The second type employs closed-loop refrigerators, primarily GM refrigerators and pulse tube refrigerators. For the first type, using liquid helium as a refrigerant, liquid helium is a non-renewable resource, expensive and largely imported. Therefore, long-term use of liquid helium for cooling significantly increases experimental costs, posing a substantial economic burden for research requiring extended testing. As for the second type, using closed-loop refrigerators, while it can directly cool magnets and samples, the resulting vibrations are often excessive, making it difficult to meet the stringent stability and accuracy requirements of researchers. Summary of the Invention

[0005] The purpose of this invention is to solve the aforementioned technical problems, thereby providing a cooling system for a dry ultra-low vibration optical device. This system uses a closed-loop GM refrigerator or a pulse tube refrigerator for cooling, and combines this with a special vibration-damping structure that suspends the cold head to obtain experimental conditions for ultra-low temperature and ultra-low vibration, thus achieving ultra-low vibration cooling and stable operation under dry conditions. The specific dry ultra-low vibration optical measurement device of this invention is as follows:

[0006] A dry, ultra-low vibration optical measurement device includes a main cavity and a cooling section. The main cavity includes an upper part, a lower part, and a top plate located above the upper part. The cooling section includes a lower vacuum chamber and an upper chiller body. The vacuum chamber is connected to the lower part of the main cavity via a first transverse bellows at its bottom. A second transverse bellows is connected to the other side of the vacuum chamber, and the second transverse bellows is connected to a vacuum port. The chiller body includes a cryogenic chiller, a lower damping bellows, and an upper damping bellows. The hot-end flange of the cryogenic chiller is supported by the lower damping bellows. The first top flange of the bellows is fixed to the first bottom flange of the lower vibration-damping bellows, while the first bottom flange of the lower vibration-damping bellows is fixed to the top flange of the vacuum chamber. The first-stage and second-stage cold heads of the cryogenic refrigerator pass downward through the lower vibration-damping bellows and extend further into the vacuum chamber. An intermediate support rod is supported on the first top flange of the lower vibration-damping bellows. The bottom end of the intermediate support rod is supported on the first top flange of the lower vibration-damping bellows, and the top end of the intermediate support rod supports the second bottom flange of the upper vibration-damping bellows. The upper vibration-damping bellows is supported on the lower vibration-damping bellows by the intermediate support rod, thus achieving a rigid connection between the two.

[0007] Furthermore, a fixed plate is provided above the second top flange of the upper vibration damping bellows, and an intermediate sealing plate is provided below the second bottom flange of the upper vibration damping bellows. The sealing of the internal space of the upper vibration damping bellows is achieved through the fixed plate and the intermediate sealing plate.

[0008] Furthermore, a floating tie rod is fixedly supported on the second bottom flange of the upper vibration damping bellows, and a middle tie plate is supported at the top of the floating tie rod. The middle tie plate is located above the fixed plate. The middle tie plate is connected to the top plate through a spring and fluororubber damping. The fixed plate is supported on the top flange of the vacuum chamber by the main support rod. The top plate and the fixed plate are rigidly connected by the upper support rod.

[0009] Furthermore, a first vibration-damping bellows connection port is provided on the side wall of the vacuum chamber, in which a first vibration-damping bellows connector is installed; a second vibration-damping bellows connection port is provided at the center of the intermediate pull plate, in which a second vibration-damping bellows connector is installed, which constitutes a connection that penetrates the intermediate pull plate and further penetrates the fixed plate downwards; the first vibration-damping bellows connector is connected to the second vibration-damping bellows connector through a flexible connecting pipe, thereby realizing the interconnection between the internal spaces of the lower vibration-damping bellows and the upper vibration-damping bellows.

[0010] Furthermore, the cryogenic refrigerator includes a primary cold head and a secondary cold head. Inside the vacuum chamber, a primary cold head cold shield is fixedly connected to the primary cold head, and the primary cold head cold shield extends vertically downward and surrounds the secondary cold head.

[0011] Furthermore, the vacuum chamber is connected to the lower part of the main cavity of the main cavity through the first transverse corrugated pipe at the bottom. A sample cold plate is set inside the main cavity, and the sample to be measured is placed on the sample cold plate for cooling. A sample cold plate support is set below the sample cold plate, and the sample cold plate support is configured to support the sample cold plate and its lower end is fixed to the sample cold plate support base plate.

[0012] Furthermore, both the sample cold plate support and the sample cold plate support base are made of thermally insulating material to prevent heat from being conducted to the sample cold plate through the connection between them and the sample cold plate; a sample area cold screen is set around the sample cold plate inside the main cavity, and the sample area cold screen is supported on the bottom transition plate by the cold screen support to provide thermal shielding for the sample cold plate; both the cold screen support and the bottom transition plate are made of thermally conductive material to transfer cold between them.

[0013] Furthermore, the vacuum chamber and the main chamber are connected by a first transverse bellows. Inside the first transverse bellows, there is a first transverse thermal bridge that is connected to the cold shield of the first-stage cold head and extends horizontally into the main chamber. At the end of the first transverse thermal bridge in the main chamber, there is a thermally conductive copper braid for the cold shield that is connected to the cold shield of the sample area. The thermally conductive copper braid cools the cold shield of the sample area to the same temperature as the cold shield of the first-stage cold head.

[0014] Furthermore, a second transverse thermal bridge connected to the secondary cold head is provided inside the first transverse corrugated tube. It also extends horizontally into the main cavity and has a secondary cold head thermal braid at its end in the main cavity. The secondary cold head thermal braid is thermally connected to the sample cold plate to cool the sample cold plate to the same temperature as the secondary cold head, thereby providing the sample with a low-temperature environment that meets the test conditions.

[0015] Furthermore, a sample top viewing window is provided on the top plate of the main cavity to facilitate observation of the working status in the main cavity, and the cryogenic refrigerator is a GM refrigerator or a pulse tube refrigerator.

[0016] This application utilizes a special vibration damping structure consisting of a lower vibration damping bellows, an upper vibration damping bellows, and a combination of springs and fluororubber damping to achieve vertical buffering and vibration damping; horizontal vibration damping is achieved through a first and second transverse bellows; and ultra-soft, thermally conductive copper braids are used to reduce the temperature of the low-temperature experimental environment to as low as 3K, achieving a vibration damping effect with a vibration amplitude of less than 10nm. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 : A front view of a dry ultra-low vibration optical device according to the present invention;

[0019] Figure 2 : Rear cross-sectional view of a dry ultra-low vibration optical device according to the present invention;

[0020] Figure 3 Side view of a dry ultra-low vibration optical device according to the present invention.

[0021] Figure label:

[0022] 1-Main cavity section; 2-Refrigeration section; 3-Finishing plate; 4-Upper part of main cavity; 5-Lower part of main cavity; 6-Top plate of main cavity; 7-Vacuum chamber; 8-Refrigerator body; 9-Second transverse corrugated pipe; 10-First transverse corrugated pipe; 11-Vacuum extraction port; 12-Cryogenic refrigerator; 13-Lower vibration damping corrugated pipe; 14-Upper vibration damping corrugated pipe; 15-Second top flange; 16-Floating tie rod; 22-Hot end flange; 23-First top flange; 24-First bottom flange; 25-Top flange; 26-First-stage cold head; 27-Second-stage cold head; 28-Intermediate support rod; 29-Second bottom flange; 30-Fixed plate; 3 1-Intermediate sealing plate; 32-Intermediate pull plate; 33-Spring; 34-Fluororubber damper; 35-Top plate; 36-Upper support rod; 37-Main support rod; 38-First vibration damping bellows connector; 39-Second vibration damping bellows connector; 40-Flexible connecting pipe; 41-First-stage cold head cold screen; 42-Sample cold plate; 43-Sample cold plate support; 44-Sample cold plate support base plate; 45-Sample area cold screen; 46-Cold screen support; 47-Bottom transition plate; 48-First transverse thermal bridge; 49-Cold screen thermal conductive copper braid; 50-Second transverse thermal bridge; 51-Second-stage cold head thermal conductive copper braid; 52-Sample top viewing window. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. It is obvious that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0024] Figure 1 This invention illustrates a dry, ultra-low vibration optical device, comprising a main cavity portion 1 and a cooling portion 2. The main cavity portion 1 and the cooling portion 2 are fixedly connected to a mounting plate 3, for example, by using stainless steel screws to fix the main cavity portion 1 and the cooling portion 2 to the mounting plate 3 respectively. The main cavity portion 1 includes an upper part 4, a lower part 5, and a top plate 6 located above the upper part 4. For example, stainless steel screws can be used to achieve a tight connection between the upper part 4, the lower part 5, and the top plate 6.

[0025] The cooling section 2 includes a lower vacuum chamber 7 and an upper cooling unit 8. The vacuum chamber 7 is connected to the lower part 5 of the main cavity of the main cavity section 1 at its bottom via a first transverse bellows 10. A second transverse bellows 9 is connected to the other side of the vacuum chamber 7, and the second transverse bellows 9 is connected to a vacuum extraction port 11. Through the vacuum extraction port 11, a vacuum can be evacuated from the vacuum chamber 7 and the internal space of the main cavity section 1 connected to it to meet the working requirements of the optical device.

[0026] The main body 8 of the refrigeration unit includes a cryogenic refrigeration unit 12, a lower vibration-damping bellows 13, and an upper vibration-damping bellows 14. The hot-end flange 22 of the cryogenic refrigeration unit 12 is supported on the first top flange 23 of the lower vibration-damping bellows 13, and the first bottom flange 24 of the lower vibration-damping bellows 13 is fixed on the top flange 25 of the vacuum chamber 7. This allows the primary cold head 26 and the secondary cold head 27 of the cryogenic refrigeration unit 12 to pass through the lower vibration-damping bellows 13 and extend further into the vacuum chamber 7. An intermediate support rod 28 is supported on the first top flange 23 of the lower vibration-damping bellows 13. The bottom end of the intermediate support rod 28 is supported on the first top flange 23 of the lower vibration-damping bellows 13, and the top end of the intermediate support rod 28 supports the second bottom flange 29 of the upper vibration-damping bellows 14. The intermediate support rod 28 supports the upper vibration-damping bellows 14 on the lower vibration-damping bellows 13, achieving a rigid connection between the two. A fixed plate 30 is provided above the second top flange 15 of the upper vibration damping bellows 14, and an intermediate sealing plate 31 is provided below the second bottom flange 29 of the upper vibration damping bellows 14. The sealing of the internal space of the upper vibration damping bellows 14 is achieved by the fixed plate 30 and the intermediate sealing plate 31.

[0027] A floating tie rod 16 is fixedly supported on the second bottom flange 29 of the upper vibration damping bellows 14. A middle tie plate 32 is supported at the top of the floating tie rod 16 and is located above the fixed plate 30. The middle tie plate 32 is connected to the top plate 35 via a spring 33 and a fluororubber damper 34. An upper support rod 36 is supported on the fixed plate 30, and its top supports the top plate 35, thus achieving a rigid connection between the top plate 35 and the fixed plate 30. The fixed plate 30 is supported on the top flange 25 of the vacuum chamber 7 via a main support rod 37. The top flange 25 of the vacuum chamber 7 and the fixed plate 30 define the installation and fixing space for the cryogenic refrigerator 12.

[0028] from Figure 3 It can be seen that the first top flange 23 of the lower damping bellows 13 is wider in the front-rear direction than the top flange 25 of the vacuum chamber 7 and the hot end flange 22 of the cryogenic refrigerator 12, thus the hot end flange 22 of the cryogenic refrigerator 12 can be supported by the first top flange 23. The top flange 25 of the vacuum chamber 7 is wider in the front-rear direction than the first bottom flange 24 of the lower damping bellows 13, thus the first bottom flange 24 is supported on the top flange 25 of the vacuum chamber 7. The first top flange 23 of the lower damping bellows 13, the second bottom flange 29 of the upper damping bellows 14, and the top plate 35 have the same size in the front-rear direction, thus enabling the support and installation of the intermediate support rod 28 and the floating tie rod 16. The top flange 25 of the vacuum chamber 7 has the same size in the front-rear direction as the fixed plate 30, thus enabling the support and installation of the main support rod 37. Furthermore, there are four main support rods 37, four intermediate support rods 28, four upper support rods 36, and four floating tie rods 16, distributed at the four corners of the corresponding flanges or plates, thereby achieving uniform support and connection and making the force distribution more uniform.

[0029] Furthermore, a first vibration-damping bellows connection port is provided on the side wall of the vacuum chamber 7, in which a first vibration-damping bellows connector 38 is installed. A second vibration-damping bellows connection port is provided at the center of the intermediate pull plate 32, in which a second vibration-damping bellows connector 39 is installed, which penetrates the intermediate pull plate 32 and further penetrates the fixed plate 30 downwards. The first vibration-damping bellows connector 38 is connected to the second vibration-damping bellows connector 39 through a flexible connecting pipe 40, thereby realizing the interconnection between the internal spaces of the lower vibration-damping bellows 13 and the upper vibration-damping bellows 14. The flexible connecting pipe 40 is preferably a latex tube.

[0030] Furthermore, by connecting a vacuum pump assembly (not shown) to the vacuum port 11, a vacuum operation can be performed on the internal space of the vacuum chamber 7 and the main chamber portion 1 connected to it, thereby also evacuating the internal cavity of the lower damping bellows 13 connected to the vacuum chamber 7; subsequently, through the flexible connecting pipe 40, an indirect vacuum operation is simultaneously achieved on the internal cavity of the upper damping bellows 14. The pressure balance between the upper damping bellows 14 and the lower damping bellows 13 is achieved through the connection of the flexible connecting pipe 40.

[0031] The cryogenic refrigerator 12 includes a primary cold head 26 and a secondary cold head 27. Inside the vacuum chamber 7, a primary cold head cold shield 41 is fixedly connected to the primary cold head 26. The primary cold head cold shield 41 extends vertically downwards and surrounds the secondary cold head 27. The primary cold head cold shield 41 is cooled to approximately 35K by the primary cold head 26. The vacuum chamber 7 is connected at its bottom to the lower part 5 of the main chamber section 1 via a first transverse corrugated pipe 10. A sample cold plate 42 is disposed inside the main chamber section 1, and the sample to be measured is placed on the sample cold plate 42 for cooling. A sample cold plate support 43 is disposed below the sample cold plate 42, and the sample cold plate support 43 is configured to support the sample cold plate 42, with its lower end fixed to a sample cold plate support base plate 44. Both the sample cold plate support 43 and the sample cold plate support base plate 44 are made of thermally insulating material to prevent heat from being conducted to the sample cold plate 42 through the connection between the two and the sample cold plate 42. Inside the main cavity 1, a sample area cold shield 45 is arranged around the sample cold plate 42. The sample area cold shield 45 is supported on the bottom transition plate 47 by a cold shield support 46, which is used to provide thermal shielding for the sample cold plate 42. Both the cold shield support 46 and the bottom transition plate 47 are made of thermally conductive material to transfer cold between them.

[0032] The vacuum chamber 7 and the main chamber section 1 are connected by a first transverse bellows 10. Inside the first transverse bellows 10, a first transverse thermal bridge 48 is provided, which is connected to the first-stage cold head cold screen 41 and extends horizontally into the main chamber section 1. At the end of the first transverse thermal bridge 48 in the main chamber section 1, a thermally conductive copper braid 49 connected to the sample area cold screen 45 is provided. The thermally conductive copper braid 49 cools the sample area cold screen 45 to the same temperature as the first-stage cold head cold screen 41, for example, 35K. A sample top viewing window 52 is provided on the top plate 6 of the main chamber to facilitate observation of the working status in the main chamber section 1.

[0033] Furthermore, a second transverse thermal bridge 50, connected to the secondary cold head 27, is provided inside the first transverse corrugated pipe 10. This bridge also extends horizontally into the main cavity portion 1, and a secondary cold head thermally conductive copper braid 51 is provided at its end located in the main cavity portion 1. The secondary cold head thermally conductive copper braid 51 is thermally connected to the sample cold plate 42 to cool the sample cold plate 42 to the same temperature as the secondary cold head 27, for example, around 3K, thereby providing the sample with a low-temperature environment that meets the testing conditions.

[0034] During operation, the vacuum pump assembly (not shown) is connected to the vacuum port 11 to evacuate the vacuum chamber 7 to 1x10. -5 A vacuum environment of mbar was created, and then the cryogenic refrigerator 12 was turned on and ran for about 2 hours. The temperature of the first-stage cold head 26 dropped to about 35K, and the temperature of the second-stage cold head 27 dropped to about 2.8K. As a result, the first-stage cold head cold shield 41 connected to the first-stage cold head 26 was also cooled to about 35K. The thermally conductive copper braid 49 of the cold shield is thermally connected to the first-stage cold head cold shield 41 through the first transverse thermal bridge 48, and is thus cooled to about 35K. The thermally conductive copper braid 49 of the cold shield cools the sample area cold shield 45 to about 35K, providing the thermal shielding required for the operation of the sample cold plate 42. Since the cold shield support 46 and the bottom transition plate 47 are both made of thermally conductive material, the cold energy can be quickly transferred to the sample area cold shield 45. The second transverse thermal bridge 50 is connected to the secondary cold head 27 and cools the secondary cold head heat-conducting copper braid 51 connected to the end of the second transverse thermal bridge 50 located in the main cavity 1 to about 3K. As a result, the sample cold plate 42 is cooled to about 3K through the secondary cold head heat-conducting copper braid 51.

[0035] The lower damping bellows 13 is connected to the vacuum chamber 7, and its interior is also evacuated. This allows for indirect evacuation of the internal cavity of the upper damping bellows 14 simultaneously via the flexible connecting pipe 40. The flexible connecting pipe 40 achieves pressure balance between the lower and upper damping bellows 13 and 14. When the cryogenic refrigerator 12 starts operating, it experiences vibrations of a certain degree, which are detrimental to optical measurements. It is desirable to reduce these vibrations to a sufficiently low level to meet measurement accuracy requirements. The lower and upper damping bellows 13 and 14 buffer the vibrations of the cryogenic refrigerator 12. Furthermore, due to the connection via the flexible connecting pipe 40, the lower and upper damping bellows 13 and 14 achieve pressure balance. At this point, the vertical vibration and the weight of the cryogenic refrigerator 12 are transmitted to the spring 33 and the fluororubber damper 34 for balance and vibration reduction through the rigid connection of the intermediate support rod 28, the floating tie rod 16, and the upper support rod 36. Spring 33 buffers vibrations through "elastic deformation" without actively dissipating energy. However, when used alone, spring 33 is prone to "vibration rebound." Fluororubber damper 34 operates based on the hysteresis effect of viscoelastic materials, possessing both "elastic" (spring-like) and "viscous" (liquid-like) properties. When subjected to vibration, its molecular chains undergo "irreversible relative sliding and friction." Part of the kinetic energy from the vibration is used to overcome intramolecular friction and is ultimately dissipated into the environment as heat; the other part is temporarily stored through elastic deformation and then released. The combined use of spring 33 and fluororubber damper 34 achieves both buffering and attenuation, resulting in superior vibration reduction.

[0036] When the cryogenic refrigerator 12 is working, the horizontal vibration is balanced and damped by the first transverse bellows 10 and the second transverse bellows 9. Through the four damping bellows arranged in the vertical and horizontal directions and the corresponding connecting structures, the vibration can be reduced to a micro-amplitude of less than 10 nm, which can fully meet the requirements of optical measurement.

[0037] The present invention has provided a detailed description of an ultra-low vibration optical measurement device. Specific examples have been used to illustrate the principles and implementation methods of the invention. The descriptions of these embodiments are merely illustrative of the method and core ideas of the present invention. For those skilled in the art, the technical solutions of the present invention are not limited to the solutions defined in the specific embodiments. Technical solutions formed by other modifications that can be obviously implemented based on ordinary technical knowledge in the art are all within the protection scope of the present invention.

Claims

1. A dry ultra-low vibration optical measurement device, comprising a main cavity section and a cooling section, the main cavity section comprising an upper part of the main cavity, a lower part of the main cavity, and a main cavity top plate located above the upper part of the main cavity, the cooling section comprising a lower vacuum chamber and an upper refrigerator body, characterized in that: The vacuum chamber is connected to the lower part of the main cavity via a first transverse bellows at its bottom. A second transverse bellows is connected to the other side of the vacuum chamber, and the second transverse bellows is connected to a vacuum port. The main body of the refrigerator includes a cryogenic refrigerator, a lower damping bellows, and an upper damping bellows. The hot-end flange of the cryogenic refrigerator is supported on the first top flange of the lower damping bellows, and the first bottom flange of the lower damping bellows is fixed to the top flange of the vacuum chamber. The primary and secondary cold heads of the cryogenic refrigerator pass downwards through the lower damping bellows and further extend into the vacuum chamber. A middle support rod is supported on the first top flange of the lower damping bellows, with the bottom end of the middle support rod supported on the first top flange of the lower damping bellows and the top end of the middle support rod supporting the upper damping bellows. The second bottom flange of the bellows supports the upper vibration-damping bellows on the lower vibration-damping bellows via an intermediate support rod, achieving a rigid connection between the two. A fixed plate is installed above the second top flange of the upper vibration-damping bellows, and an intermediate sealing plate is installed below the second bottom flange of the upper vibration-damping bellows. The fixed plate and the intermediate sealing plate seal the internal space of the upper vibration-damping bellows. A floating tie rod is fixedly supported on the second bottom flange of the upper vibration-damping bellows, and an intermediate pull plate is supported at the top of the floating tie rod. The intermediate pull plate is located above the fixed plate. The intermediate pull plate is connected to the top plate via a spring and fluororubber damping. The fixed plate is supported on the top flange of the vacuum chamber via a main support rod, and the top plate and the fixed plate are rigidly connected via an upper support rod.

2. The dry ultra-low vibration optical measurement device as described in claim 1, characterized in that: A first vibration-damping bellows connection port is provided on the side wall of the vacuum chamber, in which a first vibration-damping bellows connector is installed; a second vibration-damping bellows connection port is provided at the center of the intermediate pull plate, in which a second vibration-damping bellows connector is installed, which constitutes a connection that penetrates the intermediate pull plate and further penetrates the fixed plate downwards; the first vibration-damping bellows connector is connected to the second vibration-damping bellows connector through a flexible connecting pipe, thereby realizing the interconnection between the internal spaces of the lower vibration-damping bellows and the upper vibration-damping bellows.

3. The dry ultra-low vibration optical measurement device as described in any one of claims 1-2, characterized in that: The cryogenic refrigerator consists of a primary cold head and a secondary cold head. Inside the vacuum chamber, a primary cold head cold shield is fixedly connected to the primary cold head. The primary cold head cold shield extends vertically downwards and surrounds the secondary cold head.

4. The dry ultra-low vibration optical measurement device as described in claim 3, characterized in that: The vacuum chamber is connected to the lower part of the main chamber through the first transverse corrugated pipe at the bottom. A sample cold plate is set inside the main chamber. The sample to be measured is placed on the sample cold plate for cooling. A sample cold plate support is set below the sample cold plate. The sample cold plate support is configured to support the sample cold plate and its lower end is fixed to the sample cold plate support base plate.

5. The dry ultra-low vibration optical measurement device as described in claim 4, characterized in that: Both the sample cold plate support and the sample cold plate support base are made of thermally insulating material to prevent heat from being conducted to the sample cold plate through the connection between them and the sample cold plate. Inside the main cavity, a sample area cold screen is set around the sample cold plate. The sample area cold screen is supported on the bottom transition plate by the cold screen support to provide thermal shielding for the sample cold plate. Both the cold screen support and the bottom transition plate are made of thermally conductive material to transfer cold between them.

6. The dry ultra-low vibration optical measurement device as described in claim 5, characterized in that: The vacuum chamber and the main chamber are connected by a first transverse bellows. Inside the first transverse bellows, there is a first transverse thermal bridge that is connected to the first-stage cold head and extends horizontally into the main chamber. At the end of the first transverse thermal bridge in the main chamber, there is a thermally conductive copper braid for the cold screen that is connected to the cold screen of the sample area. The thermally conductive copper braid cools the cold screen of the sample area to the same temperature as the cold screen of the first-stage cold head.

7. The dry ultra-low vibration optical measurement device as described in claim 6, characterized in that: A second transverse thermal bridge, which is connected to the secondary cold head, is provided inside the first transverse corrugated tube. It also extends horizontally into the main cavity and has a secondary cold head thermal braid at its end in the main cavity. The secondary cold head thermal braid is thermally connected to the sample cold plate to cool the sample cold plate to the same temperature as the secondary cold head, thereby providing the sample with a low-temperature environment that meets the test conditions.

8. The dry ultra-low vibration optical measurement device as described in any one of claims 1, 4-7, characterized in that: A sample top viewing window is provided on the top plate of the main cavity, and the cryogenic refrigerator is a GM refrigerator or a pulse tube refrigerator.

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