Limiting structure for inhibiting vibration noise of monocrystalline silicon optical cavity

Abstract

The invention provides a limiting structure for inhibiting vibration noise of a monocrystalline silicon optical cavity, and relates to the technical field of lasers, the limiting structure comprises a supporting part and a limiting part which are fixed on a refrigerator, the supporting part supports the monocrystalline silicon optical cavity, the limiting part comprises a first annular structure and N limiting elements on the inner periphery of the first annular structure, and N is greater than or equal to 3. Wherein the supporting part is located in the first annular structure, the monocrystalline silicon optical cavity is also located in the first annular structure, and the limiting elements are arranged in the circumferential direction of the first annular structure and abut against the monocrystalline silicon optical cavity. The limiting structure can realize double fixation of the position of the monocrystalline silicon optical cavity through the supporting part and the limiting part, can effectively inhibit displacement of the monocrystalline silicon optical cavity due to vibration of the refrigerating machine, further can effectively inhibit vibration of the refrigerating machine and influence on measurement of frequency stability of the monocrystalline silicon optical cavity, and improves measurement accuracy of the frequency stability of the monocrystalline silicon optical cavity. Therefore, the intrinsic high-frequency stability of the low-temperature monocrystalline silicon optical cavity can be measured.

Description

Technical Field

[0001] This application relates to the field of laser technology, and in particular to a limiting structure for suppressing vibration noise in a single-crystal silicon optical cavity. Background Art

[0002] Optimizing the frequency stability of cryogenic single-crystal silicon optical cavities is crucial for realizing ultrastable lasers in the E-17 range. However, cryogenic single-crystal silicon optical cavities typically require cooling to maintain their cryogenic state. Furthermore, the cooling system generates vibrations during operation, causing the entire experimental setup to shake and resulting in displacement of the single-crystal silicon optical cavity. This severely impacts the measurement of the intrinsic high-frequency stability of the single-crystal silicon optical cavity. Summary of the Invention

[0003] In view of this, this application provides a limiting structure for suppressing vibration noise in a single-crystal silicon optical cavity, as follows:

[0004] A limiting structure for suppressing vibration noise in a single-crystal silicon optical cavity, the limiting structure being used to fix the single-crystal silicon optical cavity during frequency stability measurement at low temperatures, the limiting structure comprising:

[0005] The support portion is fixed to the refrigerator, and the support structure is used to support the single-crystal silicon optical cavity. The refrigerator is used to reduce the temperature of the single-crystal silicon optical cavity to a preset temperature.

[0006] The limiting part is fixed to the refrigerator, and the limiting part includes a first annular structure and N limiting elements disposed on the inner periphery of the first annular structure, where N is an integer greater than or equal to 3;

[0007] The supporting portion is located in the first annular structure, and the single-crystal silicon optical cavity is also located in the first annular structure. The limiting element is arranged along the circumferential direction of the first annular structure and abuts against the single-crystal silicon optical cavity.

[0008] Optionally, the limiting elements are evenly arranged along the circumferential direction of the first annular structure, and the distance between the limiting elements and the refrigerator is the same along the first direction;

[0009] Wherein, the first direction is parallel to the arrangement direction of the limiting portion and the refrigerator.

[0010] Optionally, N=3.

[0011] Optionally, the material of the first ring structure is polyetheretherketone (PEEK), and the material of the limiting element is PEEK.

[0012] Optionally, the limiting portion further includes a first flexible film covering the side of the limiting element facing the monocrystalline silicon optical cavity, the limiting element abutting against the monocrystalline silicon optical cavity through the first flexible film.

[0013] Optionally, the first flexible film is an indium film.

[0014] Optionally, the limiting portion further includes a second annular structure, which is fixed to the refrigeration unit;

[0015] The supporting portion is located in the second annular structure, and the single-crystal silicon optical cavity is also located in the second annular structure. The second annular structure is connected to the first annular structure to fix the first annular structure.

[0016] Optionally, the support portion includes a third ring structure and M support elements located on the third ring structure, where M is an integer greater than or equal to 3;

[0017] The third annular structure is fixed to the refrigeration unit;

[0018] The supporting elements are evenly distributed on the third annular structure along the circumferential direction of the third annular structure, and the supporting elements extend in a direction away from the refrigerator. The single-crystal silicon optical cavity is located at the end of the supporting element away from the refrigerator, and the side of the supporting element that contacts the single-crystal silicon optical cavity has an outwardly convex curved surface.

[0019] Optionally, M=3.

[0020] Optionally, the support portion further includes a second flexible film covering the end of the support element away from the refrigerator, and the single-crystal silicon optical cavity is located on the side of the second flexible film away from the support element.

[0021] Compared with related technologies, the beneficial effects of the technical solution of this application are as follows:

[0022] The limiting structure includes a support portion and a limiting portion fixed to the refrigerator. The support portion supports the single-crystal silicon optical cavity, and the limiting portion includes a first annular structure and N limiting elements disposed on the inner periphery of the first annular structure, where N ≥ 3. The support portion is located within the first annular structure, and the single-crystal silicon optical cavity is also located within the first annular structure. The limiting elements are arranged along the circumferential direction of the first annular structure and abut against the single-crystal silicon optical cavity. Therefore, this limiting structure can achieve dual fixation of the single-crystal silicon optical cavity's position through the support portion and the limiting portion, effectively suppressing displacement of the single-crystal silicon optical cavity due to refrigerator vibration. This effectively suppresses the impact of refrigerator vibration on the frequency stability measurement of the single-crystal silicon optical cavity, contributing to the measurement of the intrinsic high-frequency stability of the low-temperature single-crystal silicon optical cavity. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0024] The structures, proportions, sizes, etc., shown in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this application. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0025] Figure 1 A schematic diagram of a limiting structure provided in this application;

[0026] Figure 2 A schematic diagram showing the relative positional relationship between a limiting structure and a single-crystal silicon optical cavity provided in this application;

[0027] Figure 3 The frequency noise curve induced by the refrigeration machine caused by a limiting structure provided in this application;

[0028] Figure 4 A schematic diagram of another limiting structure provided in this application;

[0029] Figure 5 A schematic diagram of the limiting portion in a limiting structure provided in this application;

[0030] Figure 6A schematic diagram of the supporting portion in a limiting structure provided in this application;

[0031] Figure 7 for Figure 6 The diagram shows a side view of the supporting structure. Detailed Implementation

[0032] The embodiments of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0033] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0034] As described in the background section, the refrigerator 001 will continuously shake the entire experimental setup during operation, which may cause the single-crystal silicon optical cavity 002 to shift, seriously affecting the measurement of the frequency stability of the single-crystal silicon optical cavity 002.

[0035] Based on the above, this application provides a limiting structure for suppressing vibration noise in a single-crystal silicon optical cavity. This limiting structure is used to fix the single-crystal silicon optical cavity 002 during the measurement of its frequency stability, thereby limiting its position and preventing displacement during the measurement process. Figure 1 As shown, Figure 1 This is a schematic diagram of a limiting structure provided in this application, specifically a top view of the limiting structure, which includes a supporting part 100 and a limiting part 200.

[0036] The support portion 100 is fixed to the refrigerator 001, which is used to cool the single-crystal silicon optical cavity 002 and maintain its low temperature. The single-crystal silicon optical cavity 002 is located on the support portion 100, which supports the single-crystal silicon optical cavity 002. That is, the support portion 100 can support the single-crystal silicon optical cavity 002 during the measurement of its frequency stability.

[0037] The limiting part 200 is also fixed to the refrigerator 001, and the limiting part 200 includes a first annular structure 202 and N limiting elements 204 disposed on the inner periphery of the first annular structure 202, where N is an integer greater than or equal to 3.

[0038] Among them, such as Figure 2 As shown, Figure 2 This is a schematic diagram of a limiting structure provided in this application. The supporting portion 100 is located in the first annular structure 202, and the single-crystal silicon optical cavity 002 is also located in the first annular structure 202. That is, the supporting portion 100 is located in the hollow region of the first annular structure 202, and the single-crystal silicon optical cavity 002 is also located in the hollow region of the first annular structure 202. In other words, the supporting portion 100 is located in the region enclosed by the first annular structure 202, and the single-crystal silicon optical cavity 002 is also located in the region enclosed by the first annular structure 202.

[0039] The limiting element 204 is arranged along the circumferential direction of the first annular structure 202 and abuts against the single-crystal silicon optical cavity 002. That is, the limiting element 204 is located on the inner periphery of the first annular structure 202 and is arranged along the annular direction of the first annular structure 202. Thus, the limiting element 204 can be distributed on the outer periphery of the single-crystal silicon optical cavity 002 and abut against the single-crystal silicon optical cavity 002. In this way, the single-crystal silicon optical cavity 002 can be fixed by the limiting element 204 abutting against the single-crystal silicon optical cavity 002. That is, the single-crystal silicon optical cavity 002 can be fixed by firmly embedding the single-crystal silicon optical cavity 002 into the limiting part 200. Since the limiting part 200 is fixed to the refrigerator 001, the single-crystal silicon optical cavity 002 can be fixed to the refrigerator 001 through the limiting part 200. Therefore, the displacement of the single-crystal silicon optical cavity 002 due to the vibration of the refrigerator 001 can be suppressed, thereby effectively suppressing the impact of the vibration of the refrigerator 001 on the frequency stability measurement of the single-crystal silicon optical cavity 002.

[0040] As described above, the limiting portion 200 of the limiting structure can fix the single-crystal silicon optical cavity 002, that is, it can limit the position of the single-crystal silicon optical cavity 002 and suppress the displacement of the single-crystal silicon optical cavity 002 due to the vibration of the refrigerator 001. At the same time, the single-crystal silicon optical cavity 002 is located on the support portion 100, and the support portion 100 is fixed on the refrigerator 001. Therefore, based on the frictional force between the support portion 100 and the single-crystal silicon optical cavity 002, the displacement of the single-crystal silicon optical cavity 002 due to the vibration of the refrigerator 001 can also be suppressed. Therefore, the limiting structure can both suppress the displacement of the single-crystal silicon optical cavity 002 due to the vibration of the refrigerator 001 by the frictional force of the supporting part 100 on the single-crystal silicon optical cavity 002, and also suppress the displacement of the single-crystal silicon optical cavity 002 due to the vibration of the refrigerator 001 by fixing the single-crystal silicon optical cavity 002 by the limiting structure 200. That is, the limiting structure can achieve dual fixation of the position of the single-crystal silicon optical cavity 002, with a stronger fixing effect on the single-crystal silicon optical cavity 002, which can effectively suppress the displacement of the single-crystal silicon optical cavity 002 due to the vibration of the refrigerator 001, and thus effectively suppress the impact of the vibration of the refrigerator 001 on the frequency stability measurement of the single-crystal silicon optical cavity 002, which helps to realize the measurement of the intrinsic high frequency stability of the low-temperature single-crystal silicon optical cavity 002.

[0041] For example Figure 3 As shown, Figure 3 During the measurement of the frequency stability of the single-crystal silicon optical cavity 002, the frequency noise level induced by the vibration of the refrigerator 001 is obtained. The frequency noise level induced by the vibration of the refrigerator 001 can be obtained by measuring the frequency noise level of the single-crystal silicon optical cavity 002 under the conditions of the refrigerator 001 being turned off and on, respectively, and then calculating the noise increase when the refrigerator 001 is turned on. As shown in the figure, based on the positional limitation of the single-crystal silicon optical cavity 002 by the limiting structure, the impact of the vibration of the refrigerator 001 on the frequency stability during the 3s measurement time is less than 2E-17. Under normal circumstances, the frequency noise level induced by the vibration of the refrigerator 001 is about 2E-16 during the 3s measurement time. The frequency noise level induced by the vibration of the refrigerator 001 is reduced by at least 10 times, which shows that the limiting structure can effectively suppress the impact of the vibration of the refrigerator 001 on the frequency stability measurement of the single-crystal silicon optical cavity 002, so as to support the further measurement of the inherent frequency stability of the low-temperature single-crystal silicon optical cavity 002 at the level of 3E-17 or better. In this way, a low-temperature single-crystal silicon optical cavity 002 and a corresponding ultra-stable laser with a basic Brownian thermal noise level close to 3E-17 or better can be realized.

[0042] Meanwhile, because this limiting structure provides stronger fixation for the single-crystal silicon optical cavity 002, it can also be used to fix single-crystal silicon optical cavities 002 with longer cavity lengths, such as those with a cavity length greater than or equal to 20cm, or even reaching 40cm. A longer cavity length means greater weight, resulting in greater inertia due to the shaking of the refrigerator 001, making fixation more difficult. However, this limiting structure provides stronger fixation for the single-crystal silicon optical cavity 002, thus enabling the fixation of larger cavity lengths and demonstrating strong practicality. It should be noted that the aforementioned refrigerator 001 is typically a GM-type constant temperature vibration isolation vacuum refrigerator 001. If this limiting structure is combined with a novel 3-stage refrigerator 001 based on a flexible long corrugated tube connection to measure the frequency stability of the single-crystal silicon optical cavity 002, the vibration level of the novel 3-stage refrigerator 001 with the flexible long corrugated tube connection is significantly reduced compared to the GM-type constant temperature vibration isolation vacuum refrigerator 001. This can suppress the vibration of the refrigerator 001 to a greater extent, which helps to achieve a higher intrinsic frequency stability measurement of the low-temperature single-crystal silicon optical cavity 002.

[0043] In addition, since the single-crystal silicon optical cavity 002 can be fixed by being embedded in the first annular structure 202, the size of the limiting part 200 can be customized according to the diameter of the single-crystal silicon optical cavity 002, thereby satisfying the fixing of single-crystal silicon optical cavities 002 of more sizes, with both large and small diameters being possible, which has strong practicality.

[0044] It should be noted that the support portion 100 being located within the first annular structure 202 does not necessarily mean that the height of the support portion 100 is less than the height of the first annular structure 202 and is completely surrounded by it. Specifically, the height of the support portion 100 can be greater than the height of the first annular structure 202, meaning that a portion of the support portion 100 is within the area enclosed by the first annular structure 202, while another portion extends beyond that area. Alternatively, the height of the support portion 100 can be less than the height of the first annular structure 202, and it can be completely surrounded by it. The same explanation applies to the single-crystal silicon optical cavity 002 being located within the area enclosed by the first annular structure 202, and will not be elaborated further here.

[0045] In one embodiment of this application, such as Figure 1 and Figure 2As shown, the limiting elements 204 are uniformly arranged along the circumferential direction of the first annular structure 202, and along the first direction, the limiting elements 204 are at the same distance from the refrigerator 001, that is, the limiting elements 204 are uniformly arranged along the circumferential direction of the first annular structure 202, and the limiting elements 204 are located at the same height, that is, the limiting elements 204 are located in the same horizontal plane. The first direction is parallel to the arrangement direction of the limiting portion 200 and the refrigerator 001. It should be noted that since the limiting portion 200 is located on the refrigerator 001, that is, the limiting portion 200 and the refrigerator 001 are stacked, the limiting elements 204 in the limiting portion 200 are at the same distance from the refrigerator 001 along the arrangement direction of the limiting portion 200 and the refrigerator 001, which means that the limiting elements 204 are located at the same height.

[0046] As described above, the limiting elements 204 are uniformly distributed on the first annular structure 202, and the limiting elements 204 abut against the single-crystal silicon optical cavity 002. This ensures that the force applied by the limiting elements 204 to the single-crystal silicon optical cavity 002 is uniform, thus fixing the single-crystal silicon optical cavity 002 while maintaining the symmetrical and uniform distribution of the force applied by the limiting elements 204. This ensures that the single-crystal silicon optical cavity 002 retains its structural symmetry under the constraint of the limiting elements 204. Furthermore, the limiting elements 204 being at the same height ensures that the force-bearing positions of the single-crystal silicon optical cavity 002 are at the same height, thus keeping the single-crystal silicon optical cavity 002 in a state of force balance. Consequently, while fixing the single-crystal silicon optical cavity 002, the force applied by the limiting elements 204 to the single-crystal silicon optical cavity 002 will not cause tilting or other problems, maintaining the position of the single-crystal silicon optical cavity 002 unchanged.

[0047] It should be noted that the limiting element 204 can be a protrusion located on the inner periphery of the first annular structure 202, and the shape of the side of the protrusion that contacts the single-crystal silicon optical cavity 002 can be an outwardly convex curved surface. Specifically, the limiting element 204 can be a cylindrical protrusion located on the inner periphery of the first annular structure 202. However, since the limiting element 204 can be a cylindrical protrusion located on the inner periphery of the first annular structure 202, only a portion of the side of the limiting element 204 that contacts the single-crystal silicon optical cavity 002 is in contact with the single-crystal silicon optical cavity 002. That is, the contact area between the limiting element 204 and the single-crystal silicon optical cavity 002 is small, which can suppress damage to the single-crystal silicon optical cavity 002 caused by the limiting element 204.

[0048] In one embodiment of this application, N=3, meaning that the number of limiting elements 204 disposed on the inner periphery of the first annular structure 202 can be three. This allows for the fixation of the single-crystal silicon optical cavity 002 with a smaller number of elements, and also achieves a symmetrical distribution of the forces applied by the limiting elements 204. However, this application does not limit this to a specific number; the choice depends on the specific circumstances.

[0049] It should be noted that although the above embodiments are all described using the limiting structure having a first annular structure 202 as an example, this application does not limit the limiting structure to having only one first annular structure 202. In other embodiments of this application, depending on actual needs, the limiting structure may also include multiple first annular structures 202, and the multiple first annular structures 202 may have different heights relative to the location of the refrigerator, and each first annular structure 202 may have N limiting elements 204 on its inner periphery to fix the single-crystal silicon optical cavity 002 at different height positions, ensuring the fixing effect of the single-crystal silicon optical cavity. It should also be noted that if the limiting structure includes multiple first annular structures 202, it is preferable that the multiple first annular structures 202 have the same structure, and that the shape and layout of the limiting elements 204 on the first annular structures 202 are the same, but this application does not limit this, and it depends on the specific situation. The first annular structure 202 and the limiting element 204 thereon have the same shape, which can be that the parameters characterizing the shape are the same, such as diameter, thickness, etc.

[0050] In one embodiment of this application, the material of the first annular structure 202 can be polyetheretherketone (PEEK), and the material of the limiting element 204 can also be PEEK, so that the first annular structure 202 and the limiting element 204 have poor thermal conductivity while possessing a certain degree of flexibility. The poor thermal conductivity of the first annular structure 202 and the limiting element 204 can effectively suppress heat conduction between the single-crystal silicon optical cavity 002 and the limiting portion 200, helping the single-crystal silicon optical cavity 002 maintain a low temperature. The first annular structure 202 and the limiting element 204 have a certain degree of flexibility, which helps the first annular structure 202 to be fitted around the support portion 100 and the single-crystal silicon optical cavity 002. During the process of the first annular structure 202 being fitted around the support portion 100 and the single-crystal silicon optical cavity 002, the limiting element 204 has a certain degree of flexibility, which effectively prevents the limiting element 204 from causing damage to the single-crystal silicon optical cavity 002 as the first annular structure 202 is fitted around the support portion 100 and the single-crystal silicon optical cavity 002.

[0051] It should be noted that this application does not limit the materials of the first annular structure 202 and the limiting element 204. The materials of the first annular structure 202 and the limiting element 204 can also be other materials with poor thermal conductivity and a certain degree of flexibility.

[0052] In one embodiment of this application, such as Figure 4 As shown, Figure 4 This is a schematic diagram of a limiting structure provided in this application, specifically a top view of the limiting structure. The limiting portion 200 also includes a first flexible film 206, which covers the side of the limiting element 204 facing the single-crystal silicon optical cavity 002. The limiting element 204 abuts against the single-crystal silicon optical cavity 002 through the first flexible film 206. Due to its high flexibility, the first flexible film 206 has a large adhesion coefficient. Therefore, the covering of the limiting element 204 facing the single-crystal silicon optical cavity 002 with the first flexible film 206 increases the friction between the limiting portion 200 and the single-crystal silicon optical cavity 002, thereby improving the fixing effect of the limiting portion 200 on the single-crystal silicon optical cavity 002. Furthermore, since the first flexible film 206 has great flexibility, it can serve as a buffer medium between the limiting element 204 and the single-crystal silicon optical cavity 002, preventing the limiting element 204 from applying excessive force to the single-crystal silicon optical cavity 002 and causing damage to the single-crystal silicon optical cavity 002.

[0053] In one embodiment of this application, the first flexible film 206 may be an indium film, and the thickness of the first flexible film 206 may be 10 μm. However, this application does not limit the material and thickness of the first flexible film 206, and it depends on the specific circumstances.

[0054] In one embodiment of this application, such as Figure 5 As shown, Figure 5 This is a structural schematic diagram of the limiting part 200 (the limiting element 204 is located at the inner periphery of the first annular structure 202). Figure 5 (Not shown in the image), specifically, this is a side view of the limiting portion 200. The limiting portion 200 also includes a second annular structure 208, which is fixed to the refrigerator 001. The supporting portion 100 is located within the second annular structure 208, and the single-crystal silicon optical cavity 002 is also located within the second annular structure 208; that is, both the supporting portion 100 and the single-crystal silicon optical cavity 002 are located within the area enclosed by the second annular structure 208. Furthermore, the second annular structure 208 connects with the first annular structure 202, fixing the first annular structure 202. This allows the first annular structure 202 to be fixed to the refrigerator 001 via the second annular structure 208, thereby achieving the fixation of the single-crystal silicon optical cavity 002.

[0055] In one embodiment of this application, the material of the second annular structure 208 can be stainless steel, such as 316 stainless steel. However, this application is not limited to this, and the material of the second annular structure 208 can also be other materials with good rigidity and poor thermal conductivity, so as to better fix and maintain the shape of the first annular structure 202, and at the same time better fix the first annular structure 202 to the refrigerator 001, and maintain the low temperature of the single crystal silicon optical cavity 002.

[0056] Based on the above, for the limiting part 200, its first annular structure 202 may include a bottom ring and a thin circular ring formed on the bottom ring and integrally formed with the bottom ring. The limiting element 204 is distributed on the inner periphery of the thin circular ring. The second annular structure 208 may be an integrally formed part in the shape of an "I". Therefore, the second annular structure 208 can be sleeved on the outside of the single crystal silicon optical cavity 002 and the support part 100 from top to bottom. Its bottom can be fixed to the refrigerator 001 by multi-point fixing. The top can be drilled with 8 symmetrically distributed threaded holes. The first annular structure 202 can be fixed to the top of the second annular structure 208 through the 8 threaded holes.

[0057] In one embodiment of this application, such as Figure 6 As shown, Figure 6 This is a structural schematic diagram of the support portion 100, specifically a top view of the support portion 100. The support portion 100 includes a third annular structure 102 and M support elements 104 located on the third annular structure 102, where M is an integer greater than or equal to 3. The third annular structure 102 is fixed to the refrigerator 001. The support elements 104 are evenly distributed on the third annular structure 102 along its circumferential direction, and extend in a direction away from the refrigerator 001, so that the support elements 104 are fixed to the refrigerator 001 through the third annular structure 102. The single-crystal silicon optical cavity 002 is located at the end of the support element 104 away from the refrigerator 001, and the side of the support element 104 that contacts the single-crystal silicon optical cavity 002 has an outwardly convex curved surface. For example, the side of the support element 104 that contacts the single-crystal silicon optical cavity 002 can be hemispherical, so that a portion of the side of the support element 104 facing the single-crystal silicon optical cavity 002 is in contact with the single-crystal silicon optical cavity 002. This allows the support element 104 to support the single-crystal silicon optical cavity 002 while having a small contact area with the single-crystal silicon optical cavity 002, which can suppress the risk of damage to the single-crystal silicon optical cavity 002 caused by the support element 104.

[0058] In one embodiment of this application, the third annular structure 102 and the support element 104 in the support portion 100 are made of stainless steel, such as 316 stainless steel, so that the third annular structure 102 and the support element 104 have high rigidity, can maintain their shape, and better support the single-crystal silicon optical cavity 002. However, this application is not limited to this, and the materials of the third annular structure 102 and the support element 104 can also be other materials with good rigidity, depending on the specific circumstances.

[0059] In one embodiment of this application, M=3, meaning the number of support elements 104 can be three, so that the support portion 100 can support the single-crystal silicon optical cavity 002 with a smaller number of support elements 104. Since the single-crystal silicon optical cavity 002 must be kept horizontal, the height of the support elements 104 must be strictly consistent. The more support elements 104 there are, the more difficult it is to maintain consistent heights. Therefore, having three support elements allows the support portion 100 to support the single-crystal silicon optical cavity 002 with a smaller number of support elements 104, reducing the fabrication difficulty of the support portion 100 and thus reducing the fabrication difficulty of the limiting structure.

[0060] It should be noted that this application does not limit the number of support elements 104. In order to support and fix the single-crystal silicon optical cavity 002, the number of support elements 104 can also be other numbers, such as 4, 5, 6, etc., depending on the specific situation.

[0061] In one embodiment of this application, such as Figure 7 As shown, Figure 7 for Figure 6 The schematic diagram of the side view of the support portion 100 shown illustrates that the support portion 100 also includes a second flexible film 106. The second flexible film 106 covers the end of the support element 104 away from the refrigerator 001, and the monocrystalline silicon optical cavity 002 is located on the side of the second flexible film 106 away from the support element 104. Similar to the function of the first flexible film 206 described above, the second flexible film 106 can increase the frictional force between the support portion 100 and the monocrystalline silicon optical cavity 002, thereby suppressing displacement of the monocrystalline silicon optical cavity 002 and enhancing the fixing effect of the support portion 100 on the monocrystalline silicon optical cavity 002.

[0062] In one embodiment of this application, the second flexible film 106 may be an indium film, and the thickness of the second flexible film 106 may be 10 μm. However, this application does not limit the material and thickness of the second flexible film 106, and it depends on the specific circumstances.

[0063] The various embodiments in this specification are described in a progressive, parallel, or combined manner. Each embodiment focuses on its differences from other embodiments, and similar or identical parts between embodiments can be referred to interchangeably. For the apparatuses disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and relevant parts can be referred to the method section.

[0064] It should be noted that, in the description of this application, the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component centrally located at the same time.

[0065] It should also be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or apparatus that includes the aforementioned element.

[0066] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A limiting structure for suppressing vibration noise in a single-crystal silicon optical cavity, the limiting structure being used to fix the single-crystal silicon optical cavity during frequency stability measurement at low temperatures, characterized in that, The limiting structure includes: The support portion is fixed to the refrigerator, and the support structure is used to support the single-crystal silicon optical cavity. The refrigerator is used to reduce the temperature of the single-crystal silicon optical cavity to a preset temperature. The limiting part is fixed to the refrigerator, and the limiting part includes a first annular structure and N limiting elements disposed on the inner periphery of the first annular structure, where N is an integer greater than or equal to 3; The supporting portion is located in the first annular structure, and the single-crystal silicon optical cavity is also located in the first annular structure. The limiting element is arranged along the circumferential direction of the first annular structure and abuts against the single-crystal silicon optical cavity.

2. The limiting structure for suppressing vibration noise of a single-crystal silicon optical cavity according to claim 1, characterized in that, The limiting elements are evenly arranged along the circumferential direction of the first annular structure, and along the first direction, the limiting elements are at the same distance from the refrigerator. Wherein, the first direction is parallel to the arrangement direction of the limiting portion and the refrigerator.

3. The limiting structure for suppressing vibration noise of a single-crystal silicon optical cavity according to claim 2, characterized in that, N=3。 4. The limiting structure for suppressing vibration noise of a single-crystal silicon optical cavity according to claim 1, characterized in that, The first ring structure is made of polyetheretherketone (PEEK), and the limiting element is also made of PEEK.

5. The limiting structure for suppressing vibration noise of a single-crystal silicon optical cavity according to claim 1, characterized in that, The limiting portion further includes a first flexible film, which covers the side of the limiting element facing the monocrystalline silicon optical cavity, and the limiting element abuts against the monocrystalline silicon optical cavity through the first flexible film.

6. The limiting structure for suppressing vibration noise of a single-crystal silicon optical cavity according to claim 5, characterized in that, The first flexible film is an indium film.

7. The limiting structure for suppressing vibration noise of a single-crystal silicon optical cavity according to claim 1, characterized in that, The limiting portion further includes a second annular structure, which is fixed to the refrigeration unit; The supporting portion is located in the second annular structure, and the single-crystal silicon optical cavity is also located in the second annular structure. The second annular structure is connected to the first annular structure to fix the first annular structure.

8. The limiting structure for suppressing vibration noise of a single-crystal silicon optical cavity according to claim 1, characterized in that, The supporting portion includes a third ring structure and M supporting elements located on the third ring structure, where M is an integer greater than or equal to 3; The third annular structure is fixed to the refrigeration unit; The supporting elements are evenly distributed on the third annular structure along the circumferential direction of the third annular structure, and the supporting elements extend in a direction away from the refrigerator. The single-crystal silicon optical cavity is located at the end of the supporting element away from the refrigerator, and the side of the supporting element that contacts the single-crystal silicon optical cavity has an outwardly convex curved surface.

9. The limiting structure for suppressing vibration noise of a single-crystal silicon optical cavity according to claim 8, characterized in that, M=3。 10. The limiting structure for suppressing vibration noise of a single-crystal silicon optical cavity according to claim 8, characterized in that, The support portion further includes a second flexible film, which covers the end of the support element away from the refrigerator, and the single-crystal silicon optical cavity is located on the side of the second flexible film away from the support element.

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