A levitated optical mechanical system

Abstract

The application provides a suspended optical mechanical system, comprising a first substrate block, a suspended waveguide, a suspended support beam, a plurality of support tether groups, a suspended detection mass and an optical cavity, wherein the suspended waveguide comprises a linear main body part extending along an X direction and a plurality of connection parts arranged in sequence and at intervals along the X direction, and the support tether groups are connected to the section of the suspended waveguide with the connection parts, the stability of the connection of the support tether and the suspended waveguide is increased, the width of the suspended waveguide at the connection parts is enlarged, the optical mode can be well limited in the waveguide, and the influence of the support tether on the optical mode is minimized. The tapered part of the connection part ensures the singularity of the mode in the process of light field transmission and slows down the change trend of the width of the suspended waveguide, which is beneficial to reduce the scattering loss and further increase the quality factor. The connection part arranged on one side can ensure that the gap width between the suspended waveguide and the optical cavity is constant, thereby ensuring the optimal coupling efficiency.

Description

Technical Field

[0001] This invention belongs to the field of optical-mechanical systems technology, and relates to a levitation optical-mechanical system. Background Technology

[0002] Over the past few decades, optomechanical devices (OMs), combining nanoscale mechanical devices with ultra-low-loss optical cavities, have seen rapid development. In OMs, minute changes in displacement, force, and mass can be converted into optical signals through mechanical motion for precise measurement. Due to their unique optomechanical coupling properties, OMs are now leading candidates for realizing quantum interfaces between solid-state qubits and photons, holding immense potential value in applications such as information storage, quantum sensing, and signal processing.

[0003] In an optomechanical system composed of a classic Brie-Perot cavity (FP cavity), there exists an optical resonant cavity consisting of two mirrors, which houses a series of optical modes determined by the cavity length. One mirror is fixed, and the other mirror is connected to a detection mass. Thus, the effective length of the optical cavity is determined by the motion of the detection mass. Through this mechanism, the optomechanical system smoothly guides mechanical motion to couple with the optical resonant modes; that is, mechanical motion alters the optical resonant modes. Therefore, by monitoring changes in the optical resonant modes, the state of the mechanical motion can be inferred. To measure changes in the optical resonant modes, a method must be employed to couple the optical modes into the detection optical channel. Common coupling methods include lateral coupling, docking coupling, and end coupling. Among these, lateral coupling offers high flexibility, high coupling efficiency, and controllable eigenrate coupling rate, providing unparalleled advantages in miniaturization and high efficiency of optomechanical devices.

[0004] The principle of lateral coupling is very simple: the waveguide is placed in the near field of the optical cavity, and the input and output of light waves to the optical cavity are achieved through evanescent field coupling. In this process, the coupling efficiency varies with the refractive index contrast between the waveguide and the surrounding environment, the waveguide width, and the gap between the waveguide and the resonant cavity.

[0005] Using suspended waveguides enhances the refractive index contrast between the waveguide and its surroundings, thereby increasing the effective refractive index and eliminating mode leakage losses from the waveguide to the substrate material. To keep the waveguide suspended, a support tether must be used to connect it to the substrate and the optical cavity. However, this support tether introduces additional losses during transmission, impacting device performance.

[0006] Therefore, how to improve the waveguide structure design of suspended optical mechanical systems to further reduce transmission loss and improve coupling efficiency, thereby obtaining higher quality devices, has become an important technical problem that needs to be solved by those skilled in the art.

[0007] It should be noted that the above introduction to the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of this application and facilitating understanding by those skilled in the art. It should not be assumed that these technical solutions are known to those skilled in the art simply because they have been described in the background section of this application. Summary of the Invention

[0008] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a suspended optical-mechanical system to solve the problems of high waveguide transmission loss and low coupling efficiency in existing suspended optical-mechanical systems.

[0009] To achieve the above and other related objectives, the present invention provides a levitation optical-mechanical system, comprising:

[0010] First substrate block;

[0011] A suspended waveguide is located on one side of the first substrate block in the Y direction and is spaced apart from the first substrate block. The suspended waveguide includes a straight main body extending in the X direction and a plurality of connecting parts arranged sequentially and spaced apart in the X direction. The connecting parts are located on the side of the straight main body block facing the first substrate block and are connected to the straight main body block. The connecting parts include a first gradient part, a middle part and a second gradient part connected sequentially in the X direction. The width of the first gradient part in the Y direction gradually increases in the X direction. The middle part is straight. The width of the second gradient part in the Y direction gradually decreases in the X direction. The X direction is perpendicular to the Y direction.

[0012] A suspension support beam is located on the side of the suspension waveguide away from the first substrate block and is spaced apart from the suspension waveguide;

[0013] Multiple support rope groups correspond one-to-one with multiple connecting parts. Each support rope group includes multiple first support ropes distributed on one side of the middle part in the Y direction and multiple second support ropes on the other side in the Y direction. The two ends of the first support ropes in the Y direction are respectively fixed to the first substrate block and the middle part, and the two ends of the second support ropes in the Y direction are respectively fixed to the straight main body and the suspension support beam.

[0014] A suspended detection mass block is located on the side of the suspended support beam away from the suspended waveguide and is spaced apart from the suspended support beam;

[0015] An optical cavity is located between the suspended support beam and the suspended detection mass block. The optical cavity includes a first suspended photonic crystal and a second suspended photonic crystal spaced apart in the Y direction. The first suspended photonic crystal is fixed to the suspended support beam, and the second suspended photonic crystal is fixed to the suspended detection mass block.

[0016] Optionally, the width of the first gradient portion in the Y direction increases non-linearly along the X direction, and the width of the second gradient portion in the Y direction decreases non-linearly along the X direction.

[0017] Optionally, the edge line of the first gradient portion along the cross-section of the XY plane away from the middle portion is a concave parabolic shape, and the edge line of the second gradient portion along the cross-section of the XY plane away from the middle portion is a concave parabolic shape.

[0018] Optionally, the maximum length of the connecting portion in the X direction ranges from 4 micrometers to 10 micrometers, and the width of the middle portion in the Y direction ranges from 2 micrometers to 5 micrometers.

[0019] Optionally, the maximum length of the first gradient portion in the X direction ranges from 1 micrometer to 1.5 micrometers, and the maximum length of the second gradient portion in the X direction ranges from 1 micrometer to 1.5 micrometers.

[0020] Optionally, one of the support rope groups includes 3-7 first support ropes arranged at equal intervals in the X direction and 3-7 second support ropes arranged at equal intervals in the X direction. The width of the first support rope in the X direction ranges from 150 nanometers to 250 nanometers, and the gap width between two adjacent first support ropes ranges from 0.4 micrometers to 1 micrometer. The width of the second support rope in the X direction ranges from 150 nanometers to 250 nanometers, and the gap width between two adjacent second support ropes ranges from 0.4 micrometers to 1 micrometer.

[0021] Optionally, the levitation optical-mechanical system includes at least one pair of connecting parts, with the two connecting parts in the same pair being symmetrical about the central axis of the optical cavity in the Y direction.

[0022] Optionally, the levitation optical-mechanical system includes at least two pairs of connecting parts, wherein the maximum length of the connecting part away from the Y-direction central axis of the optical cavity in the X-direction is less than the maximum length of the connecting part near the Y-direction central axis of the optical cavity in the X-direction.

[0023] Optionally, the suspended optical-mechanical system further includes a second substrate block, a third substrate block, multiple first tethers and multiple second tethers. The second substrate block, the first tethers, the suspended detection mass block, the second tethers and the third substrate block are arranged sequentially in the X direction. The two ends of the first tethers in the X direction are respectively connected to the second substrate block and the suspended detection mass block, and the two ends of the second tethers in the X direction are respectively connected to the suspended detection mass block and the third substrate block.

[0024] Optionally, the two ends of the suspension support beam in the X direction are connected to the second substrate block and the third substrate block, respectively.

[0025] Optionally, the suspended optical-mechanical system includes a support layer and a functional layer located on the support layer. The suspended waveguide, the suspended support beam, the support tether assembly, the suspended detection mass block, and the optical cavity are all formed based on the functional layer, and the first substrate block is formed based on the support layer and the functional layer.

[0026] Optionally, the functional layer includes a silicon nitride layer.

[0027] Optionally, the levitation optical-mechanical system is applied to a gyroscope or an accelerometer.

[0028] Optionally, the optical cavity includes a defect region and a mirror region, wherein the mirror region is distributed on both sides of the defect region in the X direction, or the mirror region is distributed on both sides of the defect region in the X direction and both sides in the Y direction.

[0029] As described above, the suspended optical-mechanical system of the present invention employs a suspended waveguide, which enhances the refractive index contrast between the waveguide and the surrounding environment, thereby increasing the effective refractive index and eliminating mode leakage loss of the optical field from the waveguide to the substrate material. The suspended waveguide is suspended by multiple support tethers, wherein the suspended waveguide includes a linear main body and multiple connecting portions located on one side of the linear main body in the Y direction, with the support tethers connected to the sections of the suspended waveguide with the connecting portions. The presence of the connecting portions, on the one hand, expands the width of the suspended waveguide at this location, allowing the optical modes within the suspended waveguide to be well confined within the waveguide, thereby reducing losses caused by the support tethers and minimizing the impact of the support tethers on the optical modes; on the other hand, it increases the stability of the connection between the support tethers and the suspended waveguide. Furthermore, the connecting section includes a first gradient section, an intermediate section, and a second gradient section connected sequentially along the X direction. The width of the gradient section in the Y direction changes non-linearly along the X direction. The presence of the gradient section ensures that the width at both ends of the section with the connecting section of the suspended waveguide is consistent with the width of the straight main body of the suspended waveguide, thereby ensuring mode uniformity during optical field transmission. On the other hand, it mitigates the changing trend of the suspended waveguide width, which helps reduce scattering loss and further increases the quality factor of the device, providing greater flexibility for the design of optical input / output in optical instruments. In addition, the multiple connecting sections are located only on one side of the straight main body, which ensures that the gap width between the suspended waveguide and the optical cavity remains constant in the X direction, thereby ensuring optimal coupling efficiency. Attached Figure Description

[0030] Figure 1 The diagram shown is a schematic representation of the XY plane structure of the levitation optical-mechanical system of the present invention in a specific embodiment.

[0031] Figure 2 This diagram shows the relative positions of the suspended waveguide (partial view) and the substrate.

[0032] Figure 3 The diagram shows an enlarged structural schematic of a suspended waveguide section with a connection and its surrounding area.

[0033] Component designation explanation

[0034] 1 First substrate block

[0035] 2 Suspended waveguide

[0036] 201 Straight-line main body

[0037] 202 Connecting Part

[0038] 202a First Gradient Section

[0039] 202b Middle Section

[0040] 202c Second Gradient Section

[0041] 3 Suspension support beam

[0042] 4. Support rope assembly

[0043] 401 First Support Rope

[0044] 402 Second Support Rope

[0045] 5 Suspension test mass block

[0046] 6 Optical cavity

[0047] 601 First Suspended Photonic Crystal

[0048] 602 Second Suspended Photonic Crystal

[0049] 7 Second substrate block

[0050] 8 Third substrate block

[0051] 9 First Tether

[0052] 10 Second Tether

[0053] 11 base plate

[0054] M-defect area Detailed Implementation

[0055] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0056] Please see Figures 1 to 3 It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0057] This embodiment provides a suspended optical-mechanical system. Please refer to [link / reference]. Figure 1The diagram shows the XY-plane structure of the suspended optical-mechanical system, including a first substrate 1, a suspended waveguide 2, a suspended support beam 3, multiple support tether groups 4, a suspended detection mass block 5, and an optical cavity 6. The suspended waveguide 2 is located on one side of the first substrate 1 in the Y direction and is spaced apart from the first substrate 1. The suspended waveguide 2 includes a straight main body 201 extending along the X direction and multiple connecting parts 202 arranged sequentially and at intervals along the X direction. The connecting parts 202 are located on the straight main body 201 facing towards... The connecting portion 202 is connected to one side of the first substrate block 1 and to the straight main body portion 201. The connecting portion 202 includes a first gradient portion 202a, a middle portion 202b, and a second gradient portion 202c connected sequentially along the X direction. The width of the first gradient portion 202a in the Y direction gradually increases along the X direction. The middle portion 202b is straight. The width of the second gradient portion 202c in the Y direction gradually decreases along the X direction. The X direction is perpendicular to the Y direction. The suspended support beam 3 is located away from the first substrate block 1 and away from the straight main body portion 201. A substrate block 1 is disposed on one side and spaced apart from the suspended waveguide 2; a plurality of support tether groups 4 correspond one-to-one with a plurality of connecting parts 202. The support tether group 4 includes a plurality of first support tethers 401 distributed on one side of the middle part 202b in the Y direction and a plurality of second support tethers 402 distributed on the other side in the Y direction. The two ends of the first support tethers 401 in the Y direction are respectively fixed to the first substrate block 1 and the middle part 202b, and the two ends of the second support tethers 402 in the Y direction are respectively fixed to the straight body part 202b. 1. The suspended support beam 3; the suspended detection mass block 5 is located on the side of the suspended support beam 3 away from the suspended waveguide 2 and is spaced apart from the suspended support beam 3; the optical cavity 6 is located between the suspended support beam 3 and the suspended detection mass block 5, and the optical cavity 6 includes a first suspended photonic crystal 601 and a second suspended photonic crystal 602 spaced apart in the Y direction, the first suspended photonic crystal 601 is fixed to the suspended support beam 3, and the second suspended photonic crystal 602 is fixed to the suspended detection mass block 5.

[0058] Please see Figure 2 The diagram shows the relative positions of the suspended waveguide 2 (partial) and the substrate 11. The suspended waveguide 2 is not in contact with the substrate 11, that is, the suspended waveguide 2 is in a suspended state, which can avoid the dissipation loss caused by light energy leakage from the suspended waveguide 2 to the substrate 11 during light transmission.

[0059] In this embodiment, the suspended optical-mechanical system further includes a second substrate block 7, a third substrate block 8, multiple first tethers 9, and multiple second tethers 10. The second substrate block 7, the first tethers 9, the suspended detection mass block 5, the second tethers 10, and the third substrate block 8 are arranged sequentially in the X direction. The two ends of the first tethers 9 in the X direction are connected to the second substrate block 7 and the suspended detection mass block 5, respectively. The two ends of the second tethers 9 in the X direction are connected to the suspended detection mass block 5 and the third substrate block 8, respectively. That is, the suspended detection mass block 5 is suspended by the first tethers 9 and the second tethers 10 distributed on both sides of it in the X direction.

[0060] As an example, the two ends of the suspension support beam 3 in the X direction are connected to the second substrate block 7 and the third substrate block 8 respectively, and the suspension support beam 3 is supported by the second substrate block 7 and the third substrate block 8.

[0061] As an example, the suspended optical-mechanical system includes a support layer and a functional layer located on the support layer. The suspended waveguide 2, the suspended support beam 3, the support tether assembly 4, the suspended detection mass block 5, the optical cavity 6, the first tether 9, and the second tether 10 are all formed based on the functional layer. The first substrate block 1, the second substrate block 7, and the third substrate block 8 are all formed based on the support layer and the functional layer. The thickness of the support layer below the suspended waveguide 2 is less than the thickness of the support layers below the first substrate block 1, the second substrate block 7, and the third substrate block 8 to ensure the suspension state of the suspended support beam 3. The aforementioned substrate 11 (see...) Figure 2 This can be considered as part of the support layer.

[0062] As an example, the suspended optical-mechanical system can be built on a silicon nitride / silicon platform, that is, the support layer includes a silicon layer and the functional layer includes a silicon nitride layer.

[0063] As an example, the levitation optical-mechanical system can also be built on a silicon-on-insulator (SOI) platform, in which case the support layer includes a silicon substrate layer and a silicon oxide layer located on the silicon substrate layer, and the functional layer includes a silicon top layer.

[0064] In the suspended optical-mechanical system of this embodiment, the optical wave input and output of the optical cavity 6 are achieved through coupling by the suspended waveguide 2. The suspended waveguide 2 is placed in the near field of the optical cavity 6, and the optical mode in the optical cavity 6 is coupled into the suspended waveguide 2 and transmitted.

[0065] As an example, the optical cavity 6 includes a defect region M and a mirror region. The mirror region is distributed on both sides of the defect region M in the X direction to confine the light field in the X direction. In this embodiment, the mirror region is also distributed on both sides of the defect region M in the Y direction, thereby confining the light field in both the X and Y directions.

[0066] As an example, both the first suspended photonic crystal 601 and the second suspended photonic crystal 602 constituting the optical cavity 6 have multiple air holes. The shape of the air holes can be elliptical or other suitable shapes, and the distance between two adjacent air holes is the lattice period. The defect region M can be realized by regularly changing the structure of the air holes, such as changing the lattice period and aperture size of the air holes. For the mirror region, it is composed of air holes with the same aperture size and lattice period. In this embodiment, both the first suspended photonic crystal 601 and the second suspended photonic crystal 602 include three rows of circular air holes, wherein the row direction is the X direction. The sizes of the multiple air holes located in the defect region M and arranged in the X direction form an arithmetic sequence, gradually decreasing (or gradually increasing) from the left and right sides towards the middle. The sizes of the multiple air holes located in the mirror region are the same. The multiple air holes of the first suspended photonic crystal 601 are arranged in a triangular array, that is, adjacent rows of air holes are staggered. At the same time, except for the air holes at the outermost edges on the left and right sides, each air hole forms an equilateral triangle with the two nearest air holes in the adjacent row. The arrangement of air holes in the second suspended photonic crystal 602 is basically the same as that of the first suspended photonic crystal 601. The row of air holes closest to the gap in the first suspended photonic crystal 601 is symmetrically distributed about the X-axis.

[0067] It should be noted that, based on the requirements of different devices, the specific arrangement of the air holes in the first suspended photonic crystal 601 and the second suspended photonic crystal 602 can be flexibly adjusted, and no special restrictions are imposed here.

[0068] The suspended optical-mechanical system of this embodiment can be applied to gyroscopes, accelerometers, or other inertial measurement units. The detection principle of this suspended optical-mechanical system is explained below using an accelerometer as an example: When the suspended optical-mechanical system is subjected to a force in the Y direction, the suspended detection mass 5 will displace in the Y direction, further causing a change in the size of the optical cavity 6 (a change in the gap width between the first suspended photonic crystal 601 and the second suspended photonic crystal 602). The resonant frequency of the optical cavity 6 will change with the change in the size of the optical cavity 6, further reflecting the change in the displacement amplitude of the suspended detection mass 5. The suspended waveguide 2 is coupled to the optical cavity 6 using an evanescent field. The change in the mode in the optical cavity 6 will further cause a change in the transmission mode in the suspended waveguide 2, which is transmitted to the detection end. When the detection end receives this mode change (e.g., wavelength information), it will further reflect the acceleration of the suspended detection mass 5.

[0069] Specifically, in this embodiment, the suspended optical-mechanical system employs the support tether assembly 4 to fix the suspended waveguide 2 to the first substrate block 1 and the suspended support beam 3. Studies have shown that in suspended optical-mechanical systems using suspended waveguides without the connecting portion 202, the support tether causes additional losses and reduces the optical quality factor of the device. However, in this embodiment, the suspended optical-mechanical system using the suspended waveguide 2 with the connecting portion 202 significantly improves optical transmission efficiency and enhances the optical quality factor. This is because the section of the suspended waveguide 2 with the connecting portion 202 has a larger width, allowing the optical modes within the suspended waveguide 2 to be well confined within the waveguide, thereby reducing losses caused by the support tether and minimizing the impact of the support tether on the optical modes. Furthermore, the presence of the connecting portion 202 increases the stability of the connection between the support tether and the suspended waveguide 2.

[0070] For details, please refer to Figure 3 The diagram shows an enlarged view of the section of the suspended waveguide 2 having the connecting portion 202 and its surrounding area. In this diagram, the width w1 of the first gradient portion 202a of the connecting portion 202 facing the middle portion 202b is the same as the width w2 of the middle portion 202b, and the width of the end of the first gradient portion 202a away from the middle portion 202b is 0. The width w3 of the end of the second gradient portion 202c facing the middle portion 202b is the same as the width w2 of the middle portion 202b, and the width of the end of the second gradient portion 202c away from the middle portion 202b is 0.

[0071] In other words, the widths at both ends of the section of the suspended waveguide 2 with the connecting portion 202 are the same as the width w0 of the straight main body portion 201. That is, the expanded waveguide region is gradually tapered until the waveguide width returns to its original width, thereby ensuring that one and only a single optical mode is transmitted inside the suspended waveguide 2.

[0072] In addition, the presence of the first gradient portion 202a and the second gradient portion 202c slows down the change trend of the width of the suspended waveguide 2, which helps to reduce scattering loss and further increase the quality factor of the device, providing greater flexibility for the design of optical input / output in optical instruments.

[0073] As an example, the width of the first gradient portion 202a in the Y direction increases non-linearly along the X direction, and the width of the second gradient portion 202c in the Y direction decreases non-linearly along the X direction.

[0074] Preferably, the width gradient of the first gradient portion 202a and the second gradient portion 202c in the Y direction follows a quadratic nonlinear gradient. In this embodiment, the edge line of the first gradient portion 202a on the side away from the middle portion 202b along the cross-section of the XY plane is a concave parabolic shape, and the edge line of the second gradient portion 202c on the side away from the middle portion 202b along the cross-section of the XY plane is also a concave parabolic shape. Compared to using a straight tapered method to change the waveguide size, using a parabolic tapered method can make the size of the connection part smaller while ensuring transmission efficiency, making the device more compact and beneficial to the miniaturization and integration of the system.

[0075] Furthermore, the multiple connecting portions 202 of the suspended waveguide 2 are all located on one side of the straight main body portion 201 (the side away from the optical cavity 6), making the suspended waveguide 2 asymmetrical about its extension direction. This asymmetrical structure can ensure that the gap width between the suspended waveguide 2 and the optical cavity 6 remains unchanged in the X direction, thereby ensuring the best coupling efficiency.

[0076] It should be noted that the connecting portion 202 of the suspended waveguide 2 reduces the loss caused by the support tether, improves the transmission efficiency of the suspended waveguide 2, and the transmission efficiency increases with the increase of the width and length of the connecting portion 202. In this embodiment, in order to balance the requirements of transmission efficiency and single-mode transmission, the maximum length L1 of the connecting portion 202 in the X direction is limited to the range of 4 micrometers to 10 micrometers, the width w2 of the middle portion 202b in the Y direction is limited to the range of 2 micrometers to 5 micrometers, the maximum length L2 of the first gradient portion 202a in the X direction is limited to the range of 1 micrometer to 1.5 micrometers, and the maximum length L3 of the second gradient portion 202c in the X direction is limited to the range of 1 micrometer to 1.5 micrometers to reduce scattering loss.

[0077] Furthermore, the inventors of this application have conducted in-depth research on the properties of the support tethers, including the influence of the width, spacing, and number of support tethers on the transmission efficiency. The research shows that the transmission efficiency of light in the suspended waveguide 2 decreases with increasing number and width of the support tethers, and that increasing the spacing between adjacent support tethers also reduces the transmission efficiency. Considering the balance between mechanical strength and transmission efficiency, in this embodiment, each of the support rope groups 4 is preferably configured to include 3-7 first support ropes 401 arranged at equal intervals in the X direction and 3-7 second support ropes 402 arranged at equal intervals in the X direction. The width w4 of the first support rope 401 in the X direction is limited to the range of 150 nanometers to 250 nanometers, and the gap width g1 between two adjacent first support ropes 401 is limited to the range of 0.4 micrometers to 1 micrometer. The width w5 of the second support rope 402 in the X direction is limited to the range of 150 nanometers to 250 nanometers, and the gap width g2 between two adjacent second support ropes 402 is limited to the range of 0.4 micrometers to 1 micrometer.

[0078] Specifically, the exact number of the support tether groups 4 is determined by the chip design, such as the length of the suspension waveguide 2. The longer the suspension waveguide 2 is, the more support tether groups are required. The number of connecting parts 202 corresponds to the number of support tether groups 4, that is, each support tether group 4 is connected to one connecting part 202.

[0079] As an example, the levitation optical-mechanical system includes at least one pair of connecting portions 202, with the two connecting portions 202 in the same pair being symmetrical about the Y-direction central axis of the optical cavity 6. In this embodiment, the levitation optical-mechanical system includes two pairs of connecting portions 202 (i.e., four connecting portions 202), wherein the maximum length in the X-direction of the connecting portion 202 farther from the Y-direction central axis of the optical cavity 6 is less than the maximum length in the X-direction of the connecting portion 202 closer to the Y-direction central axis of the optical cavity.

[0080] Specifically, the overall length of the connecting portions near the optical cavity 6 (i.e., the second and third connecting portions in the X direction) is longer than the overall length of the connecting portions away from the optical cavity 6 (i.e., the first and fourth connecting portions in the X direction) to improve structural stability. Preferably, the length of the gradient region near the connecting portion of the optical cavity 6 is the same as the length of the gradient region away from the connecting portion of the optical cavity 6, only the length of the middle region differs. For example, the width of the middle region away from the connecting portion of the optical cavity 6 ranges from 2 micrometers to 6 micrometers, the width of the middle region near the connecting portion of the optical cavity 6 ranges from 3 micrometers to 7 micrometers, and the overall length of the connecting portion near the optical cavity 6 ranges from 6 micrometers to 10 micrometers.

[0081] In summary, the suspended optical-mechanical system of this invention employs a suspended waveguide, which enhances the refractive index contrast between the waveguide and its surroundings, thereby increasing the effective refractive index and eliminating mode leakage loss from the waveguide to the substrate material. The suspended waveguide is suspended by multiple support tethers. The suspended waveguide includes a linear main body and multiple connecting portions located on one side of the linear main body in the Y direction. The support tethers are connected to the sections of the suspended waveguide with these connecting portions. The presence of these connecting portions, on the one hand, expands the width of the suspended waveguide at these locations, allowing the optical modes within the suspended waveguide to be effectively confined within the waveguide, thereby reducing losses caused by the support tethers and minimizing their impact on the optical modes. On the other hand, it increases the stability of the connection between the support tethers and the suspended waveguide. Furthermore, the connecting portion includes a first gradient portion, an intermediate portion, and a second gradient portion connected sequentially along the X direction. The width of the gradient portion in the Y direction changes non-linearly along the X direction. The presence of the gradient portion ensures that the width at both ends of the section with the connecting portion of the suspended waveguide is consistent with the width of the straight main body of the suspended waveguide, thereby ensuring mode uniformity during optical field transmission. It also mitigates the changing trend of the suspended waveguide width, which helps reduce scattering loss and further increases the device's quality factor, providing greater flexibility for the design of optical input / output in optical instruments. In addition, the multiple connecting portions are located only on one side of the straight main body, ensuring that the gap width between the suspended waveguide and the optical cavity remains constant in the X direction, thus ensuring optimal coupling efficiency. Therefore, this invention effectively overcomes the various shortcomings of the prior art and has high industrial applicability.

[0082] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A levitation optical-mechanical system, characterized in that, include: First substrate block; A suspended waveguide is located on one side of the first substrate block in the Y direction and is spaced apart from the first substrate block. The suspended waveguide includes a straight main body extending in the X direction and a plurality of connecting parts arranged sequentially and spaced apart in the X direction. The connecting parts are located on the side of the straight main body block facing the first substrate block and are connected to the straight main body block. The connecting parts include a first gradient part, a middle part and a second gradient part connected sequentially in the X direction. The width of the first gradient part in the Y direction gradually increases in the X direction. The middle part is straight. The width of the second gradient part in the Y direction gradually decreases in the X direction. The X direction is perpendicular to the Y direction. A suspension support beam is located on the side of the suspension waveguide away from the first substrate block and is spaced apart from the suspension waveguide; Multiple support rope groups correspond one-to-one with multiple connecting parts. Each support rope group includes multiple first support ropes distributed on one side of the middle part in the Y direction and multiple second support ropes on the other side in the Y direction. The two ends of the first support ropes in the Y direction are respectively fixed to the first substrate block and the middle part, and the two ends of the second support ropes in the Y direction are respectively fixed to the straight main body and the suspension support beam. A suspended detection mass block is located on the side of the suspended support beam away from the suspended waveguide and is spaced apart from the suspended support beam; An optical cavity is located between the suspended support beam and the suspended detection mass block. The optical cavity includes a first suspended photonic crystal and a second suspended photonic crystal spaced apart in the Y direction. The first suspended photonic crystal is fixed to the suspended support beam, and the second suspended photonic crystal is fixed to the suspended detection mass block.

2. The levitation optical-mechanical system according to claim 1, characterized in that: The width of the first gradient section in the Y direction increases non-linearly along the X direction, and the width of the second gradient section in the Y direction decreases non-linearly along the X direction.

3. The levitation optical-mechanical system according to claim 2, characterized in that: The edge line of the first gradient portion along the XY plane away from the middle portion is a concave parabolic shape, and the edge line of the second gradient portion along the XY plane away from the middle portion is also a concave parabolic shape.

4. The levitation optical-mechanical system according to claim 1, characterized in that: The maximum length of the connecting part in the X direction is 4 micrometers to 10 micrometers, and the width of the middle part in the Y direction is 2 micrometers to 5 micrometers.

5. The levitation optical-mechanical system according to claim 4, characterized in that: The maximum length range of the first gradient part in the X direction is 1 micrometer to 1.5 micrometers, and the maximum length range of the second gradient part in the X direction is 1 micrometer to 1.5 micrometers.

6. The levitation optical-mechanical system according to claim 1, characterized in that: The aforementioned support rope assembly includes 3-7 first support ropes arranged at equal intervals in the X direction and 3-7 second support ropes arranged at equal intervals in the X direction. The width of the first support rope in the X direction ranges from 150 nanometers to 250 nanometers, and the gap width between two adjacent first support ropes ranges from 0.4 micrometers to 1 micrometer. The width of the second support rope in the X direction ranges from 150 nanometers to 250 nanometers, and the gap width between two adjacent second support ropes ranges from 0.4 micrometers to 1 micrometer.

7. The levitation optical-mechanical system according to claim 1, characterized in that: The suspended optical-mechanical system includes at least one pair of connecting parts, and the two connecting parts in the same pair are symmetrical about the central axis of the optical cavity in the Y direction.

8. The levitation optical-mechanical system according to claim 7, characterized in that: The suspended optical-mechanical system includes at least two pairs of connecting parts, wherein the maximum length of the connecting part away from the Y-direction central axis of the optical cavity in the X-direction is less than the maximum length of the connecting part near the Y-direction central axis of the optical cavity in the X-direction.

9. The levitation optical-mechanical system according to claim 1, characterized in that: The suspended optical-mechanical system further includes a second substrate block, a third substrate block, multiple first tethers and multiple second tethers. The second substrate block, the first tethers, the suspended detection mass block, the second tether and the third substrate block are arranged sequentially in the X direction. The two ends of the first tether in the X direction are connected to the second substrate block and the suspended detection mass block, respectively. The two ends of the second tether in the X direction are connected to the suspended detection mass block and the third substrate block, respectively.

10. The levitation optical-mechanical system according to claim 9, characterized in that: The two ends of the suspension support beam in the X direction are connected to the second substrate block and the third substrate block, respectively.

11. The levitation optical-mechanical system according to claim 1, characterized in that: The suspended optical-mechanical system includes a support layer and a functional layer located on the support layer. The suspended waveguide, the suspended support beam, the support tether assembly, the suspended detection mass block, and the optical cavity are all formed based on the functional layer. The first substrate block is formed based on the support layer and the functional layer.

12. The levitation optical-mechanical system according to claim 11, characterized in that: The functional layer includes a silicon nitride layer.

13. The levitation optical-mechanical system according to claim 1, characterized in that: The suspended optical-mechanical system is used in gyroscopes or accelerometers.

14. The levitation optical-mechanical system according to claim 1, characterized in that: The optical cavity includes a defect region and a mirror region. The mirror region is distributed on both sides of the defect region in the X direction, or the mirror region is distributed on both sides of the defect region in the X direction and both sides in the Y direction.

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