A transportable spatial optical reference cavity with low vibration sensitivity

Abstract

The present invention discloses a low vibration sensitivity portable spatial optical reference cavity, including a cavity structure, the cavity structure is arranged in an anti-vibration support structure, a through cylindrical hole is opened in the cavity structure, a first cavity mirror and a second cavity mirror are respectively arranged at both ends of the through cylindrical hole, a first cavity mirror compensation ring and a second cavity mirror compensation ring are respectively arranged on the outside of the first cavity mirror and the outside of the second cavity mirror, a vacuum channel connected to the through cylindrical hole is opened on the side of the cavity structure, a ridge plate is arranged on the cavity structure, and a clamping structure arranged on the anti-vibration support structure is clamped on the ridge plate. The present invention is not only structurally firm and convenient to carry; at the same time, the vibration sensitivity in three directions is low; in addition, the length in the optical axis direction and the length in two directions perpendicular to the optical axis can be adjusted as needed to reduce the volume of the optical reference cavity.

Description

Technical Field

[0001] The invention belongs to the field of ultra-stable optical reference cavities, and in particular relates to a transportable spatial optical reference cavity with low vibration sensitivity. Background Art

[0002] Ultrastable lasers are key tools in many fields such as precision measurement and gravitational wave detection. With the development of space science, the demand for portable ultrastable lasers for space applications is becoming increasingly urgent. PDH laser frequency stabilization technology is currently the most commonly used and effective method to obtain ultrastable lasers. In the laser PDH frequency stabilization technology, the resonant frequency of the optical reference cavity is used as a frequency reference. The stability of the resonant frequency depends on the stability of the reference cavity length, so the stability of the reference cavity length directly affects the frequency of the laser. The changes in the stability of the reference cavity length caused by complex vibrations in the aerospace environment have become one of the key factors limiting the further improvement of the performance of ultrastable lasers in space. Therefore, a portable space optical reference cavity with low vibration sensitivity has become a key link in the development of ultrastable lasers.

[0003] At present, the commonly used reference cavity shapes are biconical reference cavity, cubic reference cavity and spherical reference cavity. The structural feature of the biconical reference cavity is that a supporting ring is set on the central plane perpendicular to the optical axis, and the optical reference cavity is squeezed at three points on the ring. Experiments show that the vibration sensitivity in the direction of the optical axis is good, but the vibration sensitivity in the other two directions is poor. The spherical reference cavity adopts the method of supporting the ball at two points in the diameter direction of the sphere. However, the assembly of the spherical reference cavity is complicated, and the inconsistent pressure at the two supporting points will destroy the symmetry of the original mechanical structure of the sphere. The structural feature of the cubic reference cavity is that the eight vertices of the cube are cut along the diagonal of the body, and Teflon hemispheres are used to support the eight cut corners. This type of reference cavity adopts three-dimensional constraints and has low vibration sensitivity. However, these reference cavities have a common problem. The support method of these reference cavities makes the reference cavity only suitable for working in the laboratory state, and it is difficult to overcome the complex vibration environment faced by the space reference cavity. In addition, spacecraft resources are limited, and the cubic and spherical reference cavity systems are large in size and heavy in weight, which are not suitable for space applications.

[0004] In order to solve the above problems, the present invention provides a low vibration sensitivity portable space optical reference cavity. The present invention adopts three-dimensional constraints and uses a special anti-slip fixed structure to fix and support the ten positions of the reference cavity respectively, so that the optical reference cavity has a good anti-vibration effect in all three directions. At the same time, the length in the optical axis direction and the length in the two directions perpendicular to the optical axis can be adjusted as needed to reduce the volume of the optical reference cavity and adapt to space applications. Summary of the invention

[0005] The object of the present invention is to overcome the above-mentioned disadvantages of the prior art and provide a transportable spatial optical reference cavity with low vibration sensitivity.

[0006] The above-mentioned object of the present invention is achieved by the following technical solutions:

[0007] A low-vibration-sensitivity, portable spatial optical reference cavity comprises a cavity structure, wherein the cavity structure is arranged in an anti-vibration support structure, a through cylindrical hole is opened in the cavity structure, a first cavity mirror and a second cavity mirror are respectively arranged at both ends of the through cylindrical hole, a first cavity mirror compensation ring and a second cavity mirror compensation ring are respectively arranged on the outside of the first cavity mirror and the outside of the second cavity mirror, a vacuum channel connected to the through cylindrical hole is opened on the side of the cavity structure, a ridge plate is arranged on the cavity structure, and a clamping structure arranged on the anti-vibration support structure is clamped on the ridge plate.

[0008] As described above, the cavity structure includes a supporting cavity, wherein the central axis direction of the supporting cavity is the Z-axis direction, the X-axis direction and the Y-axis direction are both perpendicular to the Z-axis direction, the X-axis direction and the Y-axis direction are perpendicular, the central axis passing through the cylindrical hole is located in the Z-axis direction, and the ridge plate includes a YZ plane ridge plate, an XZ plane ridge plate, and an XY plane ridge plate.

[0009] As described above, two YZ plane ridge plates symmetrically arranged with respect to the central axis of the supporting cavity and two XZ plane ridge plates symmetrically arranged with respect to the central axis of the supporting cavity are arranged on the periphery of one end of the supporting cavity; two YZ plane ridge plates symmetrically arranged with respect to the central axis of the supporting cavity and two XZ plane ridge plates symmetrically arranged with respect to the central axis of the supporting cavity are arranged on the periphery of the other end of the supporting cavity; and two XY plane ridge plates symmetrically arranged with respect to the central axis of the supporting cavity are arranged on two opposite edges of the supporting cavity.

[0010] As described above, the vibration-resistant support structure includes a base and a cover, which are fixed to each other by a second screw group, and a square frame portion for accommodating a support cavity is formed between the base and the cover, and the support cavity is located in the square frame portion, and a first end face fixing plate and a second end face fixing plate are respectively provided at both ends of the support cavity, and the first end face fixing plate is fixed to a frame opening on one side of the square frame portion by a first screw group, and the second end face fixing plate is fixed to a frame opening on the other side of the square frame portion by a third screw group.

[0011] As described above, a central hole is provided in the middle of the first end surface fixing plate and the second end surface fixing plate for the end of the supporting cavity to pass through, and the inner walls of the central holes of the first end surface fixing plate and the second end surface fixing plate are provided with X-direction fixing seats and Y-direction fixing seats, and two X-direction fixing seats are provided on both sides of each YZ plane ridge plate, and two Y-direction fixing seats are provided on both sides of each XZ plane ridge plate, one of the XY plane ridge plates has two Z-direction fixing seats fixed to the inner side of the cover on both sides, and the other XY plane ridge plate has two Z-direction fixing seats fixed to the inner side of the base on both sides. The clamping structure includes two threaded rods, each of which has a spherical end at one end, a concave ball groove at one end of a buffer pad, and an end face of the other end of the buffer pad is a plane, and the concave ball groove is covered on the spherical end; the end face of the other end of the threaded rod is provided with a cross groove, a straight groove or a hexagonal groove, and the two threaded rods of the clamping structure corresponding to each YZ plane ridge plate are respectively installed in the X-direction threaded holes on the corresponding two X-direction fixed seats, and the buffer pads at the ends of the two threaded rods are clamped on both sides of the YZ plane ridge plate; the two threaded rods of the clamping structure corresponding to each XZ plane ridge plate are respectively installed in the Y-direction threaded holes on the corresponding two Y-direction fixed seats, and the buffer pads at the ends of the two threaded rods are clamped on both sides of the XZ plane ridge plate; the two threaded rods of the clamping structure corresponding to each XY plane ridge plate are respectively installed in the Z-direction threaded holes on the corresponding two Z-direction fixed seats, and the buffer pads at the ends of the two threaded rods are clamped on both sides of the XY plane ridge plate.

[0012] As described above, portions of the first end surface fixing plate and the second end surface fixing plate that are coaxially opposite to the X-direction threaded hole and the Y-direction threaded hole are both provided with an X-direction through hole and a Y-direction through hole.

[0013] As mentioned above, the supporting cavity, the first cavity mirror compensation ring, and the second cavity mirror compensation ring are made of the same material and are all UIE glass or fused quartz.

[0014] As mentioned above, the buffer pad is made of polyimide or polytetrafluoroethylene.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The overall structure of the support cavity in the present invention is a rectangular parallelepiped, and grooves are cut on the support cavity to form 4 YZ plane ridges, 4 XZ plane ridges, and 2 XY plane ridges. A clamping structure is designed to clamp the ridges in the three-dimensional direction to fix the support cavity. This not only makes the structure firm and convenient to carry, but also has low vibration sensitivity in the three-dimensional direction. In addition, the length in the optical axis direction and the length in the two directions perpendicular to the optical axis can be adjusted as needed to reduce the volume of the support cavity. The invention meets the requirements of aerospace devices for vibration resistance and volume weight, and is suitable for space applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0018] Figure 2 This is a three-dimensional assembly exploded view of the present invention;

[0019] Figure 3 It is a side view of the present invention.

[0020] Figure 4 For along Figure 1 Schematic cross-section of the mid-surface S;

[0021] Figure 5 This is a graph of experimental data of vibration sensitivity in the x-direction of an embodiment of the present invention;

[0022] Figure 6 This is a graph of experimental data of vibration sensitivity in the y direction of an embodiment of the present invention;

[0023] Figure 7 This is a graph of experimental data of vibration sensitivity in the z direction of an embodiment of the present invention.

[0024] In the figure:

[0025] 1- cavity structure: 11- supporting cavity, 12- first cavity mirror, 13- first cavity mirror compensation ring, 14- second cavity mirror, 15- second cavity mirror compensation ring, 16- ridge plate, 161- YZ plane ridge plate, 162- XZ plane ridge plate, 163- XY plane ridge plate;

[0026] 2-anti-vibration support structure: 21-cover, 22-base, 231-first end surface fixing plate, 232-second end surface fixing plate; 233-X-direction through hole; 234-Y-direction through hole; 24-clamping structure, 250-first screw group, 251-second screw group, 252-third screw group, 26-X-direction fixing seat, 27-Y-direction fixing seat, 28-Z-direction fixing seat;

[0027] 24- clamping structure: 241- threaded rod, 242- buffer pad. DETAILED DESCRIPTION

[0028] In order to facilitate those skilled in the art to understand and implement the present invention, the present invention is further described in detail below in combination with embodiments and with reference to the accompanying drawings. The implementation examples described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0029] Example

[0030] A low vibration sensitivity portable space optical reference cavity comprises a cavity structure 1, which is arranged in an anti-vibration support structure 2, a through cylindrical hole is provided in the cavity structure 1, the through cylindrical hole serves as an optical channel, a first cavity mirror 12 and a second cavity mirror 14 are respectively provided at both ends of the through cylindrical hole, the first cavity mirror 12 and the second cavity mirror 14 are sealed and arranged at both ends of the through cylindrical hole, a first cavity mirror compensation ring 13 and a second cavity mirror compensation ring 15 are respectively provided on the outside of the first cavity mirror 12 and the outside of the second cavity mirror 14, a vacuum channel connected to the through cylindrical hole is provided on the side of the cavity structure 1, and the vacuum channel is used to vacuum the through cylindrical hole, a ridge plate 16 is provided on the cavity structure 1, and a clamping structure 24 provided on the anti-vibration support structure 2 is clamped on the ridge plate 16. Through the above structural setting, the cavity structure 1 is clamped and fixed in the anti-vibration support structure 2 by the clamping structure 24.

[0031] In some embodiments, the cavity structure 1 includes a support cavity 11, the central axis direction of the support cavity 11 is the Z axis direction, the X axis direction and the Y axis direction are both perpendicular to the Z axis direction, the X axis direction and the Y axis direction are perpendicular, the central axis of the cylindrical hole is located in the Z axis direction, and the ridge plate 16 includes a YZ plane ridge plate 161, an XZ plane ridge plate 162, and an XY plane ridge plate 163. The clamping structure 24 includes an X-axis clamp, a Y-axis clamp, and a Z-axis clamp, the X-axis clamp is clamped on both sides of the YZ plane ridge plate in the X axis direction, the Y-axis clamp is clamped on both sides of the XZ plane ridge plate in the Y axis direction, and the Z-axis clamp is clamped on both sides of the XY plane ridge plate in the Z axis direction. The displacement of the support cavity 11 in the X-axis direction is limited by the X-axis clamp and the YZ plane ridge plate, the displacement of the support cavity 11 in the Y-axis direction is limited by the Y-axis clamp and the XZ plane ridge plate, and the displacement of the support cavity 11 in the Z direction is limited by the Z-axis clamp and the XY plane ridge plate.

[0032] In some embodiments, two YZ plane ridge plates 161 and two XZ plane ridge plates 162 are symmetrically arranged with respect to the central axis of the support cavity 11, respectively, disposed on the periphery of one end of the support cavity 11; two YZ plane ridge plates 161 and two XZ plane ridge plates 162 are symmetrically arranged with respect to the central axis of the support cavity 11, respectively, disposed on the periphery of the other end of the support cavity 11; and two XY plane ridge plates 163 are symmetrically arranged with respect to the central axis of the support cavity 11, respectively, disposed on two opposite edges of the support cavity 11.

[0033] The above-mentioned support cavity 11, 4 YZ plane ridge plates, 4 XZ plane ridge plates, and 2 XY plane ridge plates constitute a whole with mirror symmetry of a cross section perpendicular to the Z axis and passing through the center of the support cavity 11. The above-mentioned support cavity 11, 4 YZ plane ridge plates, 4 XZ plane ridge plates, and 2 XY plane ridge plates constitute a whole with central symmetry of a cross section perpendicular to the X axis and passing through the center of the support cavity 11. The above-mentioned support cavity 11, 4 YZ plane ridge plates, 4 XZ plane ridge plates, and 2 XY plane ridge plates constitute a whole with central symmetry of a cross section perpendicular to the Y axis and passing through the center of the support cavity 11. Through the above-mentioned symmetrical arrangement, the deformation of the support cavity 11 can be effectively suppressed.

[0034] In some embodiments, the vibration-resistant support structure 2 includes a base 22 and a cover 21, and the base 22 and the cover 21 are fixed by a second screw group 521. A square frame portion for accommodating the support cavity 11 is formed between the base 22 and the cover 21. The support cavity 11 is located in the square frame portion, and a first end face fixing plate 231 and a second end face fixing plate 232 are respectively provided at both ends of the support cavity 11. The first end face fixing plate 231 is fixed to the frame opening on one side of the square frame portion by a first screw group 250, and the second end face fixing plate 232 is fixed to the frame opening on the other side of the square frame portion by a third screw group 252.

[0035] As a preferred solution, the screws of the second screw group 521 are symmetrically distributed on the top surface of the cover 21 with the center of the top surface of the cover 21 and the threaded ends are screwed into the threaded holes of the base 22; the screws of the first screw group 250 are symmetrically distributed on the first end surface fixing plate 231 with the center of the first end surface fixing plate 231; the screws of the third screw group 252 are symmetrically distributed on the second end surface fixing plate 232 with the center of the second end surface fixing plate 232.

[0036] In some embodiments, a center hole is opened in the middle of the first end surface fixing plate 231 and the second end surface fixing plate 232 for the end of the supporting cavity 11 to pass through, and the inner walls of the center holes of the first end surface fixing plate 231 and the second end surface fixing plate 232 are provided with X-axis fixing seats 26 and Y-axis fixing seats 27. Two X-axis fixing seats 26 are provided on both sides of each YZ plane ridge plate 161, and two Y-axis fixing seats 27 are provided on both sides of each XZ plane ridge plate 162. Two Z-axis fixing seats 28 fixed to the inner side of the cover 21 are distributed on both sides of one XY plane ridge plate 163, and two Z-axis fixing seats 28 fixed to the inner side of the base 22 are distributed on both sides of the other XY plane ridge plate. The clamping structure 24 includes two threaded rods 241, one end of each threaded rod 241 is a spherical end, one end of the buffer pad 242 is provided with a concave ball groove, the end face of the other end of the buffer pad 242 is a plane, the concave ball groove is covered on the spherical end to form a joint-like structure; the other end face of each threaded rod 241 is provided with a cross groove, a straight groove or a hexagonal groove. The two threaded rods 241 of the clamping structure 24 corresponding to each YZ plane ridge plate are respectively installed in the X-direction threaded holes on the corresponding two X-direction fixed seats 26, and the buffer pads at the ends of the two threaded rods 241 are clamped on both sides of the YZ plane ridge plate 161; the two threaded rods 241 of the clamping structure 24 corresponding to each XZ plane ridge plate 162 are respectively installed in the Y-direction threaded holes on the corresponding two Y-direction fixed seats 27, and the buffer pads 242 at the ends of the two threaded rods 241 are clamped on both sides of the XZ plane ridge plate 162; the two threaded rods 241 of the clamping structure 24 corresponding to each XY plane ridge plate 163 are respectively installed in the Z-direction threaded holes on the corresponding two Z-direction fixed seats 28, and the buffer pads 242 at the ends of the two threaded rods 241 are clamped on both sides of the XY plane ridge plate 163.

[0037] In order to facilitate the screwing of the threaded rod 241 in the X-axis threaded hole and the Y-axis threaded hole from the outside of the first end surface fixing plate 231 and the second end surface fixing plate 232, the first end surface fixing plate 231 and the second end surface fixing plate 232 are provided with an X-axis through hole 233 and a Y-axis through hole 234 on the coaxially opposite portions of the X-axis threaded hole and the Y-axis threaded hole, so that the screwdriver can screw the threaded rod 241 in the X-axis threaded hole through the X-axis through hole, thereby clamping the YZ plane ridge plate and the XZ plane ridge plate. The screwdriver screws the threaded rod 241 in the Z-axis threaded hole through the center hole of the first end surface fixing plate 231 and the second end surface fixing plate 232, thereby clamping the XY plane ridge plate.

[0038] As a preferred solution, the support cavity 11 is a rectangular parallelepiped with a square cross-section, and the four edges at one end of the support cavity 11 are cut into rectangular parallelepiped grooves, and the remaining parts form two symmetrically arranged YZ plane ridges and two symmetrically arranged XZ plane ridges. Similarly, the four edges at the other end of the support cavity 11 are cut into rectangular parallelepiped grooves, and the remaining parts form two symmetrically arranged YZ plane ridges and two symmetrically arranged XZ plane ridges. The two ends of one of the edges in the middle of the support cavity 11 are cut into rectangular parallelepiped grooves, and the remaining parts form the XY plane ridges in the middle, and the two ends of the other opposite edge in the middle of the support cavity 11 are cut into rectangular parallelepiped grooves, and the remaining parts form the XY plane ridges in the middle.

[0039] The supporting cavity 11 , the first cavity mirror compensation ring 13 , and the second cavity mirror compensation ring 15 are made of the same material, namely UIE glass or fused quartz.

[0040] In some embodiments, the buffer pad 242 is made of a non-metallic material with poor thermal conductivity and high mechanical strength, such as polyimide or polytetrafluoroethylene.

[0041] The transportable spatial optical reference cavity designed according to this embodiment has lower vibration sensitivity. Figure 5 , Figure 6 , Figure 7 They are experimental data diagrams of the vibration sensitivity coefficients of the transportable spatial optical reference cavity designed according to this embodiment. The vibration sensitivities in the x, y, and z directions are , , .

[0042] The present invention is not limited to the above-mentioned implementation modes. The above-mentioned embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the concept of the present invention. The implementation schemes in the above-mentioned embodiments can be further combined or replaced. Various changes and improvements made to the technical solutions of the present invention by those skilled in the art all belong to the protection scope of the present invention.

Claims

1. A low vibration sensitivity portable spatial optical reference cavity, comprising a cavity structure (1), characterized in that: The cavity structure (1) is arranged in the anti-vibration support structure (2); a through-columnar hole is provided in the cavity structure (1); a first cavity mirror (12) and a second cavity mirror (14) are provided at both ends of the through-columnar hole; a first cavity mirror compensation ring (13) and a second cavity mirror compensation ring (15) are provided on the outside of the first cavity mirror (12) and the outside of the second cavity mirror (14); a vacuum channel connected to the through-columnar hole is provided on the side of the cavity structure (1); a ridge plate (16) is provided on the cavity structure (1); a clamping structure (24) provided on the anti-vibration support structure (2) is clamped on the ridge plate (16); The cavity structure (1) comprises a supporting cavity (11), wherein the central axis direction of the supporting cavity (11) is the Z-axis direction, the X-axis direction and the Y-axis direction are both perpendicular to the Z-axis direction, the X-axis direction and the Y-axis direction are perpendicular, the central axis of the cylindrical hole is located in the Z-axis direction, and the ridge plate (16) comprises a YZ plane ridge plate (161), an XZ plane ridge plate (162), and an XY plane ridge plate (163). The outer periphery of one end of the support cavity (11) is provided with two YZ plane ridge plates (161) symmetrically arranged about the central axis of the support cavity (11) and two XZ plane ridge plates (162) symmetrically arranged about the central axis of the support cavity (11); the outer periphery of the other end of the support cavity (11) is provided with two YZ plane ridge plates (161) symmetrically arranged about the central axis of the support cavity (11) and two XZ plane ridge plates (162) symmetrically arranged about the central axis of the support cavity (11); and two XY plane ridge plates (163) symmetrically arranged about the central axis of the support cavity (11) are provided on two opposite corners of the support cavity (11). The anti-vibration support structure (2) comprises a base (22) and a cover (21); the base (22) and the cover (21) are fixed to each other via a second screw group (521); a square frame portion for accommodating a support cavity (11) is formed between the base (22) and the cover (21); the support cavity (11) is located in the square frame portion; a first end surface fixing plate (231) and a second end surface fixing plate (232) are respectively sleeved at two ends of the support cavity (11); the first end surface fixing plate (231) is fixed to a frame opening on one side of the square frame portion via a first screw group (250); and the second end surface fixing plate (232) is fixed to a frame opening on the other side of the square frame portion via a third screw group (252); A central hole is provided in the middle of the first end surface fixing plate (231) and the second end surface fixing plate (232) for the end of the supporting cavity (11) to pass through; the inner walls of the central holes of the first end surface fixing plate (231) and the second end surface fixing plate (232) are provided with an X-direction fixing seat (26) and a Y-direction fixing seat (27); two X-direction fixing seats (26) are provided on both sides of each YZ plane ridge plate (161); and two Y-direction fixing seats (27) are provided on both sides of each XZ plane ridge plate (162). ), one XY plane ridge plate (163) has two Z-direction fixing seats (28) fixed to the inner side of the cover (21) on both sides, and the other XY plane ridge plate has two Z-direction fixing seats (28) fixed to the inner side of the base (22) on both sides, and the clamping structure (24) includes two threaded rods (241), one end of each threaded rod (241) is a spherical end, one end of the buffer pad (242) is provided with a concave ball groove, and the end surface of the other end of the buffer pad (242) is a plane, and the concave ball groove covers On the spherical end, the other end surface of the threaded rod is provided with a cross groove or a slot or a hexagonal groove, and the two threaded rods (241) of the clamping structure (24) corresponding to each YZ plane ridge plate are respectively installed in the X-direction threaded holes on the corresponding two X-direction fixing seats (26), and the buffer pads at the ends of the two threaded rods (241) are clamped on both sides of the YZ plane ridge plate (161); the two threaded rods (241) of the clamping structure (24) corresponding to each XZ plane ridge plate (162) are respectively installed on the opposite The two threaded rods (241) of the clamping structure (24) corresponding to each XY plane spine plate (163) are respectively installed in the Z-direction threaded holes on the corresponding two Z-direction fixed seats (28), and the buffer pads (242) at the ends of the two threaded rods (241) are clamped on both sides of the XY plane spine plate (163).

2. A low vibration sensitivity portable spatial optical reference cavity according to claim 1, characterized in that: Parts of the first end surface fixing plate (231) and the second end surface fixing plate (232) that are coaxially opposite to the X-direction threaded hole and the Y-direction threaded hole are both provided with an X-direction through hole (233) and a Y-direction through hole (234).

3. The low vibration sensitivity portable spatial optical reference cavity according to claim 1, characterized in that: The supporting cavity (11), the first cavity mirror compensation ring (13), and the second cavity mirror compensation ring (15) are made of the same material and are all UIE glass or fused quartz.

4. The low vibration sensitivity transportable spatial optical reference cavity according to claim 1, characterized in that: The buffer pad (242) is made of polyimide or polytetrafluoroethylene.

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