A coaxial and off-axis combined rotary optical interconnect

Abstract

The application discloses a coaxial and paraxial combined rotary optical interconnector, and belongs to the field of rotary interconnectors, which comprises a first optical interconnection assembly and a second optical interconnection assembly, the first optical interconnection assembly comprises a rotary shaft, the rotary shaft comprises a hollow rotary shaft and a solid rotary shaft which are symmetrically arranged at intervals, a first collimator is arranged in the hollow rotary shaft, the hollow rotary shaft and the solid rotary shaft are connected through a U-shaped connecting frame which is symmetrically arranged upwards and downwards, an L-shaped shell is arranged at intervals, a second collimator and a third collimator are arranged at two ends in the L-shaped shell respectively, and the first collimator and the second collimator constitute a coaxial interconnector; the direction of the third collimator is always downward; the second interconnection assembly comprises a fourth collimator, the fourth collimator is vertically upward, coaxially arranged with the third collimator, and constitutes a paraxial interconnector. The interconnector provided by the application combines coaxial interconnection and paraxial interconnection, realizes rotary input and fixed position output of optical signals, and realizes bidirectional and continuous transmission of optical signals.

Description

A rotating optical interconnect combining coaxial and paraaxial axes Technical Field

[0001] This invention belongs to the fields of optical signal transmission and rotating interconnects, and relates to an optical interconnect for optical signal transmission, particularly a rotating optical interconnect combining coaxial and paraaxial types. Background Technology

[0002] Optical signal rotational interconnection technology is a rotational coupling technology applied in the field of space optical communication. It can continuously transmit optical signals from a rotating component at one end to a fixed component at the other end. The device that realizes the optical signal rotational interconnection function is called a rotating optical connector, also known as a "smooth ring". Rotating optical connectors can be widely used in rotating spindles, robotic arms, rotating towers, aiming and tracking equipment, etc.

[0003] Based on the transmission path of the optical signal within the device, optical interconnects can be divided into coaxial and off-axis types. In a coaxial interconnect, the input, output, and internal optics are located at the center of the rotation axis, and the optical signal transmission path follows the center of the rotation axis. An off-axis interconnect, on the other hand, has its input, output, and internal optics separated from the rotation axis. Coaxial optical interconnects are widely used, have simple optical paths, and are easy to implement; however, when the center position of the rotation axis is occupied, further design of off-axis interconnects is required. Optical interconnects based on the direct coupling principle are the most common. Direct coupling utilizes free-space optics principles to directly align optical communication devices through an external mechanical structure. The direct coupling method mainly uses an optical beam expander system to directly align the output and receive signals. After optical beam expansion, the allowable range of off-axis deviation is increased, making this method easy to implement while achieving high optical coupling efficiency, and the mechanical structure is easy to manufacture. Therefore, this method is very suitable for the design of coaxial and off-axis optical interconnects on a rotation axis.

[0004] In summary, a rotating optical interconnect is designed based on the coaxial direct coupling method of optical devices to realize the coaxial and off-axis transmission of optical signals on the rotating axis in sequence, thus completing the bidirectional transmission of optical signals under dynamic rotation.

[0005] No patent documents related to this application were found through a search. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art. This invention designs a rotating optical interconnect that combines coaxial and off-axis interconnects. This interconnect combines coaxial interconnects and off-axis interconnects to realize the rotational input of optical signals and the fixed position output, thereby realizing bidirectional and continuous transmission of optical signals.

[0007] The technical problem solved by this invention is achieved through the following technical solution:

[0008] A coaxial and off-axis combined rotating optical interconnect includes a first optical interconnect component and a second optical interconnect component. The first optical interconnect component is disposed above the second optical interconnect component. The first optical interconnect component includes a rotating shaft, a U-shaped connecting frame, and an L-shaped housing. The rotating shaft includes a hollow rotating shaft and a solid rotating shaft arranged symmetrically at intervals, and the hollow rotating shaft and the solid rotating shaft are connected by a U-shaped connecting frame arranged symmetrically at the top and bottom. The L-shaped housing is disposed at the interval between the hollow rotating shaft and the solid rotating shaft, and one end of the L-shaped housing is coaxially fixed to the end of the hollow rotating shaft. A second collimator and a third collimator are respectively disposed at both ends inside the L-shaped housing. Furthermore, a first collimator is installed inside the hollow rotating shaft. The first collimator is connected to a rotating optical fiber. The second collimator and the third collimator are connected through a stationary third optical fiber. The first collimator and the second collimator form a coaxial interconnect. The direction of the third collimator is always downward. The second interconnect assembly includes a base support frame, a collimator fixing base, and a fourth collimator. The base support frame is symmetrically arranged at the lower part of the collimator fixing base. The fourth collimator is installed on the collimator fixing base. The fourth collimator is connected to a stationary optical fiber. The fourth collimator is vertically upward and coaxially arranged with the third collimator, forming a bypass interconnect.

[0009] Furthermore, both the rotating optical fiber and the stationary optical fiber are equipped with APC optical connectors. The rotating optical fiber is fixed to the surface of the hollow rotating shaft, and a small hole is reserved on the hollow rotating shaft for it to pass through. Its APC connector serves as the rotating input port for optical signals; the APC connector of the stationary optical fiber serves as the fixed output port for optical signals.

[0010] Furthermore, the first collimator, the second collimator, the third collimator, and the fourth collimator are all fixed by collimator fixing plates.

[0011] Moreover, one end of the L-shaped outer shell is fixed to one end of the hollow rotating shaft by a deep groove ball bearing; and the outer wall of one end of the L-shaped outer shell is installed on the inner wall of the deep groove ball bearing, while the other end is suspended and always pointing downwards.

[0012] Moreover, the hollow shaft, solid shaft, and U-shaped connecting frame are integrated into one unit.

[0013] Moreover, the first, second, third, and fourth collimators are all the same collimator, and the light emitted by the front lens of each identical collimator is nearly parallel light. When two identical collimators are coupled, the coupling efficiency is highest when the distance D between the front surfaces of the two collimators is the working distance. The working distance refers to twice the distance between the front surface of the collimator and the waist position.

[0014] Furthermore, the working principle of the interconnect includes the following:

[0015] 1) The optical signal on the hollow shaft is transmitted through the rotating optical fiber on the hollow shaft to the first collimator inside the hollow shaft, and is converted into near-parallel light by the first collimator for emission;

[0016] 2) The nearly parallel light emitted from the first collimator is incident on the second collimator;

[0017] 3) The second collimator couples the received near-parallel light into the third optical fiber, transmits it to the third collimator, and then outputs it from the third collimator;

[0018] 4) The near-parallel light emitted from the third collimator is transmitted to the fourth collimator, which couples the received near-parallel light into the stationary optical fiber at the rear end, thus completing the fixed-position output of the optical signal.

[0019] The collimator output beam diameter d can be estimated using the following formula:

[0020] (1)

[0021] Where λ is the wavelength of the light used, MFD is the mode field diameter, and f is the focal length of the collimator.

[0022] Maximum waist-cinching distance To maintain collimation, the distance between the waist of the lens and the lens can be the furthest possible distance, which is approximately estimated using the following formula:

[0023] (2)

[0024] The distance D between the front faces of the first collimator and the second collimator, and between the third collimator and the fourth collimator, must meet the following conditions:

[0025] (3)

[0026] When the rotating shaft rotates dynamically, the U-shaped connecting frame will block the spatial light transmission of the third and fourth collimators twice within one rotation, causing a temporary interruption in signal transmission. The signal interruption time accounts for a very small percentage of a cycle and does not affect the normal operation of the entire device. Based on the principle of optical path reversibility, the optical signal transmitted along the above-mentioned optical path from the first collimator to the second collimator to the third collimator to the fourth collimator can return completely along the original path. The entire optical interconnection system is reversible, realizing bidirectional optical transmission.

[0027] The advantages and positive effects of this invention are:

[0028] This invention proposes a rotating optical interconnect combining coaxial and off-axis interconnects, suitable for optical signal transmission on a rotating axis, enabling bidirectional optical signal transmission between the rotating axis of a first optical interconnect component and a second optical interconnect component. A pair of coaxially aligned fiber collimators, i.e., coaxial interconnects, are installed in the hollow portion of the rotating axis. One end of the coaxial interconnect is connected to a rotating optical fiber fixed to the surface of the rotating axis, and the other end is connected to a third collimator at a 90° angle to it via a stationary third optical fiber, converting the axial optical signal into a radial optical signal. Under the influence of gravity, the third collimator always points downwards and forms an off-axis interconnect with the fourth collimator of the second optical interconnect component. The interconnect proposed in this invention combines coaxial and off-axis interconnects, enabling rotating input and fixed-position output of optical signals, achieving bidirectional and continuous optical signal transmission. Attached Figure Description

[0029] Figure 1 is a schematic diagram of the external structure of the spatial rotating optical interconnect combining coaxial and paraaxial elements of the present invention.

[0030] Figure 2 is a detailed cross-sectional view of the spatial rotating optical interconnect combining coaxial and paraaxial elements of the present invention.

[0031] Figure 3 is a front view schematic diagram of the spatial rotating optical interconnect that combines coaxial and paraaxial structures according to the present invention.

[0032] In the diagram: 1-1: Rotating optical fiber; 1-2: Stationary optical fiber; 1-3: Hollow shaft; 1-4: Solid shaft; 1-5: U-shaped connector; 1-6: L-shaped outer shell; 1-7: Collimator mounting base; 1-8: Base support frame; 1-9: Rotating optical fiber through hole; 2-1: First collimator; 2-2: Second collimator; 2-3: Third collimator; 2-4: Fourth collimator; 2-5: Collimator mounting plate; 2-6: Deep groove ball bearing; 2-7: Third optical fiber. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are merely descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0034] As shown in Figure 1, a coaxial and off-axis combined rotating optical interconnect includes a first optical interconnect component and a second optical interconnect component. The first optical interconnect component is disposed above the second optical interconnect component. The first optical interconnect component includes a rotating shaft, a U-shaped connector, an L-shaped housing, a rotating optical fiber, a first collimator, a second collimator, and a third collimator. The rotating shaft includes a hollow rotating shaft and a solid rotating shaft symmetrically arranged at intervals, and the hollow rotating shaft and the solid rotating shaft are connected by the U-shaped connector. Specifically, the hollow rotating shaft and the solid rotating shaft are arranged coaxially and spaced at a certain distance, and the U-shaped connector connects the hollow rotating shaft and the solid rotating shaft at this distance. The hollow shaft, solid shaft, and U-shaped connecting frame are integrated into one unit. The L-shaped outer shell is located at the interval between the hollow shaft and the solid shaft, and one end of the L-shaped outer shell is coaxially fixed to the end of the hollow shaft. A second collimator and a third collimator are respectively provided at both ends inside the L-shaped outer shell. A first collimator is also provided inside the hollow shaft. The first collimator is connected to a rotating optical fiber 1-1. The second collimator and the third collimator are connected through a third optical fiber 2-7. The first collimator and the second collimator form a coaxial interconnect. The interior of the L-shaped outer shell 1-6 and the third collimator remain stationary with the outer shell. The direction of the third collimator 2-3 is always downward.

[0035] The second interconnect component includes a base support frame, a collimator fixing base, a collimator fixing plate, and a fourth collimator. The base support frame is symmetrically arranged at the lower part of the collimator fixing base. The collimator fixing plate is arranged inside the collimator fixing base. The fourth collimator is fixed on the collimator fixing plate. A stationary optical fiber is connected to the fourth collimator. The fourth collimator is vertically upward and coaxially arranged with the third collimator, forming a cross-axis interconnect.

[0036] The rotating optical fiber 1-1 and the stationary optical fiber 1-2 are both equipped with APC optical connectors. The rotating optical fiber 1-1 is fixed to the surface of the rotating shaft, and a small hole 1-9 is reserved on the hollow rotating shaft for it to pass through. The rotating optical fiber 1-1 rotates with the shaft, and its APC connector serves as the rotating input port for optical signals. The stationary optical fiber 1-2 is led out from the collimator mounted on the fixed platform inside the interconnect and remains stationary. Its APC connector serves as the fixed output port for optical signals and can be used to connect with other fixed devices.

[0037] As shown in Figure 2, the first collimator is fixed to the hollow part of the hollow rotating shaft by a collimator fixing plate 2-5, and the collimator fixing plate is installed inside the hollow rotating shaft by screws. The collimator fixing plate and the hollow rotating shaft 1-3 remain stationary. The collimator fixing plate 2-5 has a high-precision hole along the axial direction. The first collimator 2-1 is tightly fitted inside the plate with zero clearance through the high-precision hole. The above structure realizes the synchronous rotation of the first collimator 2-1 and the rotating shaft.

[0038] One end of the L-shaped outer shell 1-6 is fixed to one end of the hollow rotating shaft via a deep groove ball bearing 2-6. The L-shaped outer shell is designed with an L-shaped structure. The outer wall of one end of the L-shaped structure is installed on the inner wall of the deep groove ball bearing 2-6, while the other end is suspended. The deep groove ball bearing 2-6 only provides support to one end of the L-shaped outer shell 1-6 and does not provide rotational power. Therefore, based on the gravity of the other end of the L-shaped outer shell 1-6, the outer shell will not be affected by the rotation of the rotating shaft and will remain stationary. That is, one end of the L-shaped outer shell 1-6 will always face downwards and be perpendicular to the fixed platform.

[0039] The light emitted by the front lens of each collimator is nearly parallel. When two identical collimators are coupled, the coupling efficiency is highest when the distance D between the front surfaces of the two collimators is the working distance. The working distance refers to twice the distance between the front surface of the collimator and the waist position.

[0040] In summary, the transmission process of optical signals is as follows:

[0041] 1. The optical signal on the rotating shaft 1-3 is transmitted through the rotating optical fiber 1-1 on the shaft to the first collimator 2-1 inside the shaft, and is converted into near-parallel light by the first collimator 2-1 for emission;

[0042] 2. The nearly parallel light emitted from the first collimator 2-1 is incident on the second collimator 2-2;

[0043] 3. The second collimator 2-2 couples the received near-parallel light into the third optical fiber 2-7, transmits it to the third collimator 2-3, and exits from the third collimator 2-3;

[0044] 4. The near-parallel light emitted from the third collimator 2-3 is transmitted to the fourth collimator 2-4, which is fixed in the mounting base 1-7. The fourth collimator couples the received near-parallel light into the stationary optical fiber 1-2 at the rear end, thus completing the fixed-position output of the optical signal.

[0045] The collimator output beam diameter d can be estimated using the following formula:

[0046] (1)

[0047] Where λ is the wavelength of the light used, MFD is the mode field diameter, and f is the focal length of the collimator.

[0048] Maximum waist-cinching distance To maintain collimation, the distance between the waist of the lens and the lens can be the furthest possible distance, which is approximately estimated using the following formula:

[0049] (2)

[0050] Therefore, the distance D between the front end faces of the first collimator 2-1 and the second collimator 2-2, and the third collimator 2-3 and the fourth collimator 2-4, must satisfy the following condition:

[0051] (3)

[0052] When the rotating shaft rotates dynamically, the U-shaped connecting frame 1-6 will block the spatial light transmission of the third collimator 2-3 and the fourth collimator 2-4 twice within one rotation, causing a temporary interruption in signal transmission. However, the signal interruption time accounts for a very small percentage within one cycle and does not affect the normal operation of the entire device.

[0053] Based on the principle of optical path reversibility, the optical signal transmitted along the above-mentioned optical path—from the first collimator 2-1 to the second collimator 2-2 to the third collimator 2-3 to the fourth collimator 2-4—can return completely along the original path. The entire optical interconnect system is reversible, realizing bidirectional optical transmission.

[0054] This invention proposes a rotating optical interconnect combining coaxial and off-axis designs, suitable for optical signal transmission along a rotating axis, enabling bidirectional optical signal transmission between the rotating axis of a first optical interconnect component and a second optical interconnect component. A pair of coaxially aligned fiber collimators, i.e., coaxial interconnects, are installed in the hollow portion of the rotating axis. One end of the coaxial interconnect is connected to a rotating optical fiber fixed to the surface of the rotating axis, and the other end is connected to a third collimator at a 90° angle to it via a stationary third optical fiber, converting the axial optical signal into a radial optical signal. The third collimator, serving as one end of the off-axis interconnect, always points downwards under gravity and, together with the fourth collimator of the second optical interconnect component, forms a pair of off-axis interconnects. The other end of the off-axis interconnect is connected to a stationary optical fiber.

[0055] The interconnect proposed in this invention combines coaxial interconnection and off-axis interconnection to achieve rotating input and fixed-position output of optical signals, enabling bidirectional and continuous transmission of optical signals.

[0056] Although embodiments and drawings of the present invention have been disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, variations and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. A rotating optical interconnect combining coaxial and paraaxial axes, characterized in that: The system includes a first optical interconnect component and a second optical interconnect component. The first optical interconnect component is disposed above the second optical interconnect component. The first optical interconnect component includes a rotating shaft, a U-shaped connecting frame, and an L-shaped housing. The rotating shaft includes a hollow rotating shaft and a solid rotating shaft arranged symmetrically at intervals, and the hollow rotating shaft and the solid rotating shaft are connected by a U-shaped connecting frame arranged symmetrically at the top and bottom. The L-shaped housing is disposed at the interval between the hollow rotating shaft and the solid rotating shaft, and one end of the L-shaped housing is coaxially fixed to the end of the hollow rotating shaft. A second collimator and a third collimator are respectively disposed at both ends inside the L-shaped housing. The hollow rotating shaft also contains... The first collimator is connected to a rotating optical fiber. The second collimator and the third collimator are connected through a stationary third optical fiber. The first collimator and the second collimator form a coaxial interconnect. The direction of the third collimator is always downward. The second optical interconnect assembly includes a base support frame, a collimator fixing base, and a fourth collimator. The base support frame is symmetrically arranged on the lower part of the collimator fixing base. The fourth collimator is arranged on the collimator fixing base and is connected to a stationary optical fiber. The fourth collimator is vertically upward and coaxially arranged with the third collimator, forming a cross-axis interconnect.

2. The coaxial and paraaxial combined rotating optical interconnect according to claim 1, characterized in that: Both the rotating optical fiber and the stationary optical fiber are equipped with APC optical connectors. The rotating optical fiber is fixed to the surface of the hollow rotating shaft, and a small hole is reserved on the hollow rotating shaft for it to pass through. Its APC connector serves as the rotating input port for optical signals; the APC connector of the stationary optical fiber serves as the fixed output port for optical signals.

3. The coaxial and paraaxial combined rotating optical interconnect according to claim 1, characterized in that: The first collimator, the second collimator, the third collimator, and the fourth collimator are all fixed by collimator fixing plates.

4. The rotating optical interconnect combining coaxial and paraaxial connections according to claim 1, characterized in that: One end of the L-shaped housing is fixed to one end of the hollow rotating shaft by a deep groove ball bearing; and the outer wall of one end of the L-shaped housing is installed on the inner wall of the deep groove ball bearing, while the other end is suspended and always facing downwards.

5. The coaxial and paraaxial combined rotating optical interconnect according to claim 1, characterized in that: The hollow shaft, solid shaft, and U-shaped connecting frame are integrated into one unit.

6. The coaxial and paraaxial combined rotating optical interconnect according to claim 1, characterized in that: The first, second, third, and fourth collimators are all the same collimator, and the light emitted by the front lens of each of the same collimators is nearly parallel light. When two identical collimators are coupled, the coupling efficiency is the highest when the distance D between the front surfaces of the two collimators is the working distance. The working distance refers to twice the distance between the front surface of the collimator and the waist position.

7. A rotating optical interconnect combining coaxial and paraaxial components according to any one of claims 1-6, characterized in that: The working principle of the interconnect includes the following: 1) The optical signal on the hollow shaft is transmitted to the first collimator inside the hollow shaft via the rotating optical fiber on the hollow shaft, and is converted into near-parallel light for emission by the first collimator; 2) The near-parallel light emitted from the first collimator is incident on the second collimator; 3) The second collimator couples the received near-parallel light into the third optical fiber, and then transmits it to the third collimator, from which it is emitted; 4) The near-parallel light emitted from the third collimator is transmitted to the fourth collimator, and the fourth collimator couples the received near-parallel light into the stationary optical fiber at the rear end, completing the fixed-position output of the optical signal; the diameter d of the collimator output beam is estimated according to the following formula: (1) Where λ is the wavelength of the light used, MFD is the mode field diameter, f is the focal length of the collimator, and the maximum beam waist distance is... To maintain collimation, the distance between the waist of the lens and the lens can be the furthest possible distance, which is approximately estimated using the following formula: (2) The distance D between the front end faces of the first collimator and the second collimator, and between the third collimator and the fourth collimator, must meet the following conditions: (3) When the rotating shaft rotates dynamically, the U-shaped connecting frame will block the spatial light transmission of the third collimator and the fourth collimator twice within one rotation, causing the signal transmission to be temporarily interrupted. The signal interruption time accounts for a very small proportion within one cycle and does not affect the normal operation of the entire device. Based on the principle of optical path reversibility, the optical signal transmitted along the above-mentioned optical path from the first collimator to the second collimator to the third collimator to the fourth collimator can return completely along the original path. The entire optical interconnection system is reversible and realizes bidirectional optical transmission.

Images