Vacuum sealed multi-channel ultra-stable optical reference cavity

Abstract

The invention relates to the technical field of optical precision instruments, in particular to a vacuum sealing multichannel ultra-stable optical reference cavity which comprises a cavity part, a plurality of cavity mirrors, a vacuum sealing assembly and a plurality of heat shielding layers, and a vent hole and a plurality of communicated light passing channels are formed in the cavity part; the vent hole is communicated with the light transmission channel; the plurality of cavity mirrors are fixed on the peripheral side of the cavity part and cover the light transmission channel; the vacuum sealing assembly is fixed to the top of the cavity part and communicates with the vent hole, and the vacuum sealing assembly is configured to apply a vacuum environment to the interiors of all the light passing channels through the vent hole; a plurality of high-reflectivity cavity mirrors are located in the heat shielding layer on the innermost side, and the cavity part is fixed to the heat shielding layer on the innermost side; the adjacent heat shielding layers are arranged at intervals, and any heat shielding layer is provided with a through hole communicating with the internal space of all the heat shielding layers. The cavity can stably operate in an air environment without a vacuum maintaining system, and can be applied to a portable ultra-stable laser system and an application scene of compact space precision measurement.

Description

Technical Field

[0001] The present invention relates to the technical field of optical precision instruments, and in particular to a vacuum-sealed multi-channel ultra-stable optical reference cavity. Background Art

[0002] Fabry-Perot optical cavities are widely used in active laser frequency stabilization and the generation of ultra-narrow linewidth lasers. Due to their excellent cavity length stability and extremely narrow spectral width, they can be used for laser frequency stabilization to achieve sub-hertz-level and long-term frequency stable laser output.

[0003] The traditional ultra-stable Fabry-Perot cavity uses ultra-low expansion coefficient glass as the cavity spacer. The cavity mirrors are optically glued to both sides of the cavity. In order to ensure the stability of the cavity length, the optical empty channels in the cavity mirrors on both sides need to be evacuated to a high vacuum to avoid the influence of pressure fluctuations on the refractive index. At the same time, the cavity needs to ensure temperature stability at the nano-K level, and needs to have a multi-layer heat shielding structure and active temperature control to reduce cavity length fluctuations.

[0004] The ultra-stable optical reference cavity used for active laser frequency stabilization is usually placed in a high vacuum chamber. However, the high vacuum in the vacuum chamber makes the ultra-stable optical cavity bulky, and the currently portable ultra-stable optical reference cavity also has a large volume, which increases the cost of using it in resource-constrained space precision measurement environments.

[0005] At present, portable ultra-stable optical reference cavities still face major challenges. How to ensure the high vacuum degree of the cavity while reducing the volume of the ultra-stable cavity requires solving many problems. In order to solve this technical problem, the present invention proposes a vacuum-sealed multi-channel ultra-stable optical reference cavity. Summary of the invention

[0006] In view of this, the present invention provides a vacuum-sealed multi-channel ultra-stable optical reference cavity to solve the problem of how to ensure a high vacuum degree of the cavity while reducing the volume of the ultra-stable cavity.

[0007] In a first aspect, the present invention provides a vacuum-sealed multi-channel ultra-stable optical reference cavity, comprising:

[0008] A cavity member, wherein a vent hole and a plurality of interconnected light-passing channels are provided inside; the vent hole is connected to all the light-passing channels;

[0009] A plurality of cavity mirrors, fixed outside the light passage of the cavity member and covering the light passage;

[0010] A vacuum sealing component, fixed to the top of the cavity member and communicated with the vent hole, the vacuum sealing component being configured to apply a vacuum environment to the interior of all the light passages through the vent hole;

[0011] A plurality of heat shielding layers are sequentially sleeved from the inside to the outside, the cavity part and the plurality of cavity mirrors with high reflectivity are located inside the innermost heat shielding layer, and the cavity part is fixed inside the vacuum chamber; any of the heat shielding layers is provided with a through hole connecting the internal spaces of all the heat shielding layers for light transmission.

[0012] The above-mentioned structure, the cavity part has a multi-channel structure, an internal vacuum seal and a multi-layer heat shielding layer, has the advantages of portability, small size, and no need for a vacuum holding system. The multi-layer heat shielding layer reduces external thermal interference. Compared with the traditional ultra-stable optical reference cavity that needs to be placed in a high vacuum chamber, resulting in the traditional ultra-stable optical reference cavity having a larger volume, the vacuum-sealed multi-channel ultra-stable optical reference cavity provided by the present invention has a multi-channel structure, an internal vacuum seal and a multi-layer heat shielding layer. Therefore, it can operate stably in an air environment without a vacuum holding system, and can be used in application scenarios of portable ultra-stable laser systems and compact space precision measurement.

[0013] In an optional embodiment, adjacent heat shielding layers are arranged at intervals.

[0014] In an optional embodiment, the cavity member is a polyhedron structure, including a tetrahedron, a hexahedron, an octahedron, etc.

[0015] In an optional embodiment, the cavity member is fixed to the innermost heat shielding layer by a support structure arranged thereon, and the support structure is configured to adopt multi-point support.

[0016] In an optional embodiment, the support structure includes an external frame and a plurality of supports having one end fixed to the external frame, and the other end of the supports is connected to the cavity member;

[0017] The support is made of a material with low thermal conductivity and applies a radial force to fix the cavity member.

[0018] In an optional embodiment, the vacuum sealing component uses an indium sealing process to seal the cavity part, and the vacuum degree inside the cavity part is lower than 10 -6 Pa.

[0019] In an optional embodiment, the cavity member is made of a material with a low thermal expansion coefficient, including but not limited to ULE low expansion glass, microcrystalline glass, composite ceramics, etc.

[0020] In the above structure, the cavity part uses low vibration sensitive material (material with low thermal expansion coefficient) and a support structure is arranged between the cavity part and the first layer of heat shielding layer. The support structure reduces the torsional force on the cavity part and compensates for the external force by optimizing the coaxiality design of the support point, so as to reduce the sensitivity of the cavity to external vibrations and enable it to maintain high stability in portable applications.

[0021] In an optional embodiment, the heat shielding layer is made of a material with a low thermal expansion coefficient, and the surface is coated with a low emissivity material.

[0022] In an optional embodiment, the surface of any one of the heat shielding layers is gold-plated.

[0023] In the above structure, the heat shielding layer is made of a material with a low thermal expansion coefficient. The surface of the heat shielding layer is gold-plated to reduce heat radiation. The cavity is placed in a sealed vacuum chamber so that the heat exchange between the cavity and the outside world is only heat conduction and heat radiation.

[0024] In an optional embodiment, the through holes at corresponding positions on all the heat shielding layers are coaxially arranged, and an optical fiber coupling structure is fixed at the position of the through holes on the outermost heat shielding layer.

[0025] The vacuum-sealed multi-channel ultra-stable optical reference cavity provided by the present invention has the following advantages:

[0026] 1. The present invention provides a vacuum-sealed multi-channel ultra-stable optical reference cavity, comprising a cavity part, a plurality of cavity mirrors, a vacuum sealing assembly, and a plurality of heat shielding layers sequentially arranged from the inside to the outside, wherein an air vent and a plurality of interconnected light-transmitting channels are arranged inside the cavity part; the air vent is connected to the light-transmitting channel; a plurality of cavity mirrors are fixed on the circumference of the cavity part and cover the light-transmitting channels; the vacuum sealing assembly is fixed to the top of the cavity part and is connected to the air vent, and the vacuum sealing assembly is configured to apply a vacuum environment to the inside of all light-transmitting channels through the air vent; the cavity part and a plurality of cavity mirrors with high reflectivity are located inside the innermost heat shielding layer, and the cavity part is fixed to the innermost heat shielding layer; adjacent heat shielding layers are arranged at intervals, and any heat shielding layer is provided with a through hole connecting the internal spaces of all heat shielding layers.

[0027] The above structure is provided with a cavity part, and a vent hole and a plurality of interconnected light-passing channels are provided inside the cavity part; the vent hole is connected with the light-passing channel, in order to achieve high vacuum sealing inside the light-passing channel, avoid the change of refractive index affecting the stability of the cavity, and reduce the interference of the pressure fluctuation in the cavity on the resonant frequency of the cavity, therefore, the present invention provides a vacuum sealing component on the cavity part, and the vacuum sealing component is connected with the vent hole on the cavity part, and is used to evacuate all the light-passing channels through the vent hole. Among them, the vacuum sealing component can adopt the existing exhaust valve, and its purpose is to connect the vent hole in the cavity part through the exhaust valve to achieve high vacuum in the light-passing channel inside the cavity part. Light-passing channels are designed on multiple sides of the cavity part to facilitate the input and output of multiple laser beams. The design of multiple light-passing channels allows the cavity part to support applications such as multi-laser locking and single wavelength multi-channel locking, and enhances the applicability of the cavity part. Several cavity mirrors are fixed at the light passage on the side of the cavity part and the light passage is sealed. The cavity part adopts a multi-layer heat shielding structure to effectively isolate the influence of external temperature fluctuations on the cavity part, thereby improving the temperature stability of the cavity part, and any heat shielding layer is provided with a through hole connecting the internal space of all heat shielding layers, and the through hole is used for external laser to enter and leave the cavity of the cavity part. The cavity part has a multi-channel structure, internal vacuum sealing and multi-layer heat shielding layers, and has the advantages of portability, small size, and no need for a vacuum holding system. The multi-layer heat shielding layer reduces external thermal interference. Compared with the traditional ultra-stable optical reference cavity, which needs to be placed in a high vacuum chamber, resulting in a larger volume of the traditional ultra-stable optical reference cavity, the vacuum-sealed multi-channel ultra-stable optical reference cavity provided by the present invention has a multi-channel structure, internal vacuum sealing and multi-layer heat shielding layers, so it can operate stably in an air environment without a vacuum holding system, and can be used in portable ultra-stable laser systems and compact space precision measurement application scenarios.

[0028] 2. The present invention provides a vacuum-sealed multi-channel ultra-stable optical reference cavity, wherein the cavity components are made of materials with a low thermal expansion coefficient of 2, and the cavity components are fixed to the innermost heat shielding layer by a support structure arranged thereon, and the support structure is configured to adopt multi-point support.

[0029] In the above structure, the cavity part uses low vibration sensitive material (material with low thermal expansion coefficient) and a support structure is arranged between the cavity part and the first layer of heat shielding layer. The support structure reduces the torsional force on the cavity part and compensates for the external force by optimizing the coaxiality design of the support point, so as to reduce the sensitivity of the cavity to external vibrations and enable it to maintain high stability in portable applications.

[0030] 3. The present invention provides a vacuum-sealed multi-channel ultra-stable optical reference cavity, wherein the heat shielding layer is made of a material with a low thermal expansion coefficient, and the surface is coated with a low emissivity material. The surface of any of the heat shielding layers is gold-plated.

[0031] In the above structure, the heat shielding layer is made of a material with a low thermal expansion coefficient, such as a ceramic material. The surface of the heat shielding layer is gold-plated to reduce heat radiation. The cavity part is placed in a sealed vacuum chamber, so that the heat exchange between the cavity part and the outside world is only heat conduction and heat radiation. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 A schematic structural view of a vacuum-sealed multi-channel ultra-stable optical reference cavity provided in an embodiment of the present invention;

[0034] Figure 2 A schematic diagram of the sealing process of a vacuum-sealed multi-channel ultra-stable optical reference cavity provided in an embodiment of the present invention.

[0035] Description of reference numerals:

[0036] 1- Cavity parts;

[0037] 2-Laparoscope;

[0038] 3-vacuum sealing assembly; 31-vacuum sealing indium ring; 32-vacuum valve;

[0039] 4- first heat shielding layer;

[0040] 5- Second heat shielding layer;

[0041] 6- The third heat shielding layer;

[0042] 7-Outer vacuum chamber;

[0043] 8- Solenoid valve;

[0044] 9-Fiber coupling structure;

[0045] 10- Support structure. DETAILED DESCRIPTION

[0046] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0048] Example

[0049] Fabry-Perot optical cavities are widely used in active laser frequency stabilization and the generation of ultra-narrow linewidth lasers. Due to their excellent cavity length stability and extremely narrow spectral width, they can be used for laser frequency stabilization to achieve sub-hertz-level and long-term frequency stable laser output.

[0050] The traditional ultra-stable Fabry-Perot cavity uses ultra-low expansion coefficient glass as the cavity spacer. The cavity mirrors are optically glued to both sides of the cavity. In order to ensure the stability of the cavity length, the optical empty channels in the cavity mirrors on both sides need to be evacuated to a high vacuum to avoid the influence of pressure fluctuations on the refractive index. At the same time, the cavity needs to ensure temperature stability at the nano-K level, and needs to have a multi-layer heat shielding structure and active temperature control to reduce cavity length fluctuations.

[0051] The ultra-stable optical reference cavity used for active laser frequency stabilization is usually placed in a vacuum chamber with a high vacuum degree. However, the vacuum chamber with a high vacuum degree makes the ultra-stable optical cavity bulky, and the currently portable ultra-stable optical reference cavity also has a large volume, which increases the cost of using it in a resource-constrained space precision measurement environment.

[0052] Currently, portable ultra-stable optical reference cavities still face major challenges. How to ensure the high vacuum degree of the cavity while reducing the volume of the ultra-stable cavity requires solving many problems. In order to solve this technical problem, this embodiment proposes a vacuum-sealed multi-channel ultra-stable optical reference cavity.

[0053] In this embodiment, if Figure 1 As shown, the vacuum-sealed multi-channel ultra-stable optical reference cavity includes a cavity part 1, a plurality of cavity mirrors 2, a vacuum sealing component 3, a plurality of heat shielding layers sequentially arranged from the inside to the outside, an electromagnetic valve 8, a fiber coupling structure 9 and a supporting structure 10.

[0054] In this embodiment, a vent and a plurality of interconnected light-passing channels are provided inside the cavity part 1; the vent is connected to the light-passing channel; a plurality of cavity mirrors 2 are fixed on the periphery of the cavity part 1 and cover the light-passing channel; a vacuum sealing component 3 is fixed to the top of the cavity part 1 and is connected to the vent, and the vacuum sealing component 3 is configured to apply a vacuum environment to the inside of all light-passing channels through the vent; the cavity part 1, a plurality of cavity mirrors 2 with high reflectivity and the vacuum sealing component 3 are located inside the innermost heat shielding layer, and the cavity part 1 is fixed to the innermost heat shielding layer; adjacent heat shielding layers are arranged at intervals, and any heat shielding layer is provided with a through hole connecting the internal spaces of all heat shielding layers.

[0055] The above structure is provided with a cavity part 1, and a vent hole and several interconnected light-passing channels are provided inside the cavity part 1; the vent hole is connected with the light-passing channel, in order to achieve high vacuum sealing inside the light-passing channel, avoid the change of refractive index affecting the stability of the cavity, and reduce the interference of the pressure fluctuation in the cavity on the resonance frequency of the cavity, so this embodiment is provided with a vacuum sealing component 3 on the cavity part 1, and the vacuum sealing component 3 is connected with the vent hole on the cavity part 1, and is used to evacuate all the light-passing channels through the vent hole. Among them, the vacuum sealing component 3 can adopt an existing exhaust valve, and its purpose is to connect the vent hole in the cavity part 1 through the exhaust valve to achieve high vacuum in the light-passing channel inside the cavity part 1. After the high vacuum inside the cavity part is completed, the vacuum sealing component 3 is closed. Light-passing channels are designed on multiple sides of the cavity part 1 to facilitate the input and output of multiple laser beams. The design of multiple light-passing channels allows the cavity part 1 to support applications such as multi-laser locking and single wavelength multi-channel locking, and enhances the applicability of the cavity part 1. A number of cavity mirrors 2 are fixed to the light passage on the side of the cavity component 1 by optical bonding. The cavity component 1 adopts a multi-layer heat shielding structure to effectively isolate the influence of external temperature fluctuations on the cavity component 1, thereby improving the temperature stability of the cavity component 1, and any heat shielding layer is provided with a through hole that connects the internal space of all heat shielding layers and is coaxial with the cavity mirror 2. The through hole is used for external laser to enter and leave the cavity of the cavity component 1, and a high-transmittance window piece is installed in the through hole of the innermost heat shielding layer to increase the heat shielding effect.

[0056] The vacuum-sealed multi-channel ultra-stable optical reference cavity provided in the present embodiment has a multi-channel structure, an internal vacuum seal and a multi-layer heat shielding layer, and has the advantages of portability, small size, and no need for a vacuum holding system. The multi-layer heat shielding layer reduces external thermal interference. Compared with the traditional ultra-stable optical reference cavity that needs to be placed in a high vacuum chamber, resulting in the traditional ultra-stable optical reference cavity having a larger volume, the vacuum-sealed multi-channel ultra-stable optical reference cavity provided in the present embodiment has a multi-channel structure, an internal vacuum seal and a multi-layer heat shielding layer. Therefore, it can operate stably in an air environment without a vacuum holding system, and can be used in portable ultra-stable laser systems and application scenarios of precision measurement in compact spaces.

[0057] In this embodiment, the vacuum sealing component 3 uses an indium sealing process to seal the cavity part 1, and the vacuum degree inside the cavity part 1 is less than 10 -6 Pa.

[0058] The vent holes of the traditional reference cavity are exposed, and the entire cavity is placed in a vacuum chamber, which is evacuated from atmospheric pressure to 10 -6 Pa. The disadvantage is that during the vacuuming process, oil and debris will enter the cavity through the vent hole and contaminate the cavity mirror 2. At the same time, the entire vacuum chamber is bulky. This embodiment uses a hot-pressed indium sealing process to directly seal the cavity part 1. After the cavity part 1 with a light passage and a vent hole is processed, the lens is bonded to one side of the vent hole using an optical bonding method, and the other side is sealed with a hot-pressed indium vacuum valve. After the indium vacuum valve is sealed, the light passage is evacuated, and then the vacuum passage is clamped off to achieve a reference cavity without the need for an external vacuum chamber. The vacuum degree inside the cavity part is 10 -6 Pa level, it can operate without a huge vacuum chamber, providing a new method for the limited volume resources in space applications.

[0059] like Figure 1 As shown, in this embodiment, the heat shielding layer includes a first heat shielding layer 4, a second heat shielding layer 5, a third heat shielding layer 6 and an outer vacuum chamber 7; the first heat shielding layer 4 is at the innermost side, the outer vacuum chamber 7 is at the outermost side, and the second heat shielding layer 5 and the third heat shielding layer 6 are arranged from the inside to the outside. Among them, there are intervals between the first heat shielding layer 4, the second heat shielding layer 5, the third heat shielding layer 6 and the outer vacuum chamber 7. It can be understood that in some other embodiments, the number of heat shielding layers can be set according to needs, for example, it can be set to four layers, five layers, six layers, etc.

[0060] In this embodiment, the heat shielding layer is a material with a low thermal expansion coefficient, and the surface is coated with a low emissivity material. Materials with low thermal conductivity and low thermal expansion coefficient, such as ceramic materials, can also be selected. In this embodiment, multiple heat shielding layers are used to gradually reduce external thermal interference, and the surface of the heat shielding layer is gold-plated to reduce thermal radiation. An electromagnetic valve 8 is installed on the outer vacuum chamber 7, and the electromagnetic valve is used to evacuate the space inside the outer vacuum chamber 7 to a high vacuum degree, so that the heat exchange between the cavity part 1 and the outside world only exists in heat conduction and heat radiation. After the cavity is launched into space, the electromagnetic valve is opened so that the vacuum degree inside the outer vacuum chamber 7 is the same as the vacuum degree of the satellite.

[0061] In this embodiment, if Figure 1As shown, the through holes at corresponding positions on all heat shielding layers are coaxially arranged, and the outermost heat shielding layer is fixed with fiber coupling structures 9 at the positions of several through holes. By fixing the fiber coupling structures 9 at the positions of the through holes on the heat shielding layer, a plug-and-play optical path design can be realized without the need for an additional cavity optical path.

[0062] Specifically, Figure 1 Take this as an example to illustrate: Figure 1 The left side is the light hole. Figure 1 The middle right side is a light exit hole, and a fiber coupling structure 9 is fixed at the light entrance hole, which is used as a light source. That is, on the outermost heat shielding layer, only one fiber coupling structure 9 is fixed at the light entrance hole.

[0063] In this embodiment, the cavity member 1 is a polyhedral structure. Figure 1 In the embodiment shown, the cavity member 1 is a hexahedral structure. In some other embodiments, an octahedral structure or other structures may also be adopted.

[0064] In this embodiment, the cavity member 1 is made of a material with a low thermal expansion coefficient, such as ULE, microcrystalline glass, composite ceramic structure, etc.

[0065] Furthermore, in this embodiment, the cavity member 1 is fixed to the innermost heat shielding layer by a support structure 10 disposed thereon, and the support structure 10 is configured to adopt multi-point support.

[0066] Specifically, Figure 1 As shown, the support structure 10 includes an external frame and a plurality of supports having one end fixed to the external frame, and the other end of the supports is connected to the cavity member;

[0067] The support is made of a material with low thermal conductivity and applies a radial force to fix the cavity member.

[0068] In the above structure, the cavity part 1 is made of low vibration sensitive material (material with low thermal expansion coefficient) and a support structure 10 is arranged between the cavity part 1 and the first heat shielding layer 4. The support structure 10 reduces the torsional force on the cavity part 1 and compensates for the external force by optimizing the coaxiality design of the support point. The support structure 10 uses titanium alloy screws (supports) to apply radial force to the external frame, and the supports use low thermal conductivity materials to reduce heat conduction. Finite element analysis is used to optimize the installation position of the support structure 10 and the angle of the light passage, so that when there is micro-vibration in the outside world, the support structure 10 attenuates the external acceleration through the vibration reduction characteristics of its material. The support structure 10 reduces the sensitivity of the cavity part to external vibrations through its own vibration reduction characteristics, so that it can maintain high stability in portable applications.

[0069] In this embodiment, if Figure 2As shown, the vacuum-sealed multi-channel ultra-stable optical reference cavity includes a cavity mirror 2, a cavity component 1, a vacuum-sealed indium ring 31 and an exhaust valve 32.

[0070] Specifically, Figure 2 As shown, one end of the exhaust channel is sealed, and the cavity part 1 and the exhaust valve 32 are sealed by a vacuum sealing indium ring 31. The exhaust valve 32 is fixed to the cavity part 1 by a hot pressing indium sealing process, and the exhaust channel is vacuumed by an external exhaust pump. The exhaust channel is connected to all optical channels. The vacuum degree of all optical channels can be achieved below 10 -6 Pa. After achieving high vacuum in all optical channels, pinch off the exhaust channel and seal it to achieve long-term sealing treatment.

[0071] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A vacuum-sealed multi-channel ultra-stable optical reference cavity, characterized in that: include: A cavity member (1) is provided with a vent hole and a plurality of interconnected light passages; The vent hole is in communication with all the light passages; A plurality of cavity mirrors (2) fixed on the outside of the light passage of the cavity member (1) and covering the light passage; A vacuum sealing component (3) is fixed to the cavity member (1) and communicated with the vent hole, wherein the vacuum sealing component (3) is configured to apply a vacuum environment to the interior of all the light passages through the vent hole; A plurality of heat shielding layers are sequentially sleeved from the inside to the outside, the cavity part (1), the plurality of cavity mirrors (2) with high reflectivity and the vacuum sealing component (3) are located inside the innermost heat shielding layer, and the cavity part (1) is fixed to the innermost heat shielding layer; any of the heat shielding layers is provided with a through hole connecting the internal spaces of all the heat shielding layers.

2. The vacuum-sealed multi-channel ultra-stable optical reference cavity according to claim 1, characterized in that: Adjacent heat shielding layers are arranged at intervals.

3. The vacuum-sealed multi-channel ultra-stable optical reference cavity according to claim 1 or 2, characterized in that: The cavity member (1) is a polyhedral structure.

4. The vacuum-sealed multi-channel ultra-stable optical reference cavity according to claim 3, characterized in that: The cavity member (1) is fixed to the innermost heat shielding layer by a support structure (10) arranged thereon, and the support structure (10) is configured to adopt multi-point support.

5. The vacuum-sealed multi-channel ultra-stable optical reference cavity according to claim 4, characterized in that: The support structure (10) comprises an external frame and a plurality of supports having one end fixed to the external frame, and the other end of the supports being connected to the cavity member; The support is made of a material with low thermal conductivity and applies a radial force to fix the cavity member.

6. The vacuum-sealed multi-channel ultra-stable optical reference cavity according to any one of claims 1 to 5, characterized in that: The vacuum sealing component (3) uses an indium sealing process to seal the cavity part (1), and the vacuum degree inside the cavity part (1) is less than 10 -6 Pa.

7. The vacuum-sealed multi-channel ultra-stable optical reference cavity according to any one of claims 1 to 6, characterized in that: The cavity member (1) is made of a material with a low thermal expansion coefficient.

8. The vacuum sealed multi-channel ultra-stable optical reference cavity according to any one of claims 1 to 7, characterized in that: The heat shielding layer is made of a material with a low thermal expansion coefficient, and its surface is coated with a low emissivity material.

9. The vacuum-sealed multi-channel ultra-stable optical reference cavity according to claim 7, characterized in that: The surface of any of the heat shielding layers is gold-plated.

10. The vacuum sealed multi-channel ultra-stable optical reference cavity according to any one of claims 1 to 9, characterized in that: The through holes at corresponding positions on all the heat shielding layers are coaxially arranged, and optical fiber coupling structures (9) are fixed at the positions of several of the through holes on the outermost heat shielding layer.

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