Space double-channel optical fiber rotary connector

Abstract

The invention relates to an optical fiber rotary connector, in particular to a spatial dual-channel optical fiber rotary connector, and aims to overcome the defects that an existing dual-channel optical fiber rotary connector is poor in environmental adaptability or high in assembly difficulty or difficult to complete two-way signal transmission. The spatial dual-channel optical fiber rotary connector comprises a rotor sleeve, a stator shell, a first optical assembly and a second optical assembly, the rotor sleeve and the stator shell are coaxially and rotatably connected, and the first optical assembly comprises a first input assembly, a beam expanding assembly, a beam shrinking assembly and a first output assembly which are sequentially arranged along an optical path; the first input assembly and the beam expanding assembly are arranged in the rotor sleeve, input a first optical signal and form a collimated hollow light beam; the beam shrinking assembly and the first output assembly are arranged in the stator shell, and the collimated hollow light beam is shrunk and output; and the second optical assembly is arranged in a second input assembly and a second output assembly in the stator shell and is used for transmitting a second optical signal.

Description

Technical Field

[0001] The invention relates to an optical fiber rotary connector, in particular to a spatial dual-channel optical fiber rotary connector. Background Art

[0002] Fiber optic rotary connectors are important optical devices for signal transmission. They use optical fiber as a transmission medium to achieve signal transmission between a rotating platform and another stationary platform. Dual-channel fiber optic rotary connectors can achieve dual-channel signal transmission at the same time, which is convenient for transmitting multiple signals. Compared with single-channel fiber optic rotary connectors, they have the advantage of multi-channel transmission and are convenient for providing backup channels for signal transmission. Fiber optic rotary connectors used in the aerospace field need to have the characteristics of high reliability and long life. At present, with the rapid development of the aerospace industry, multi-channel fiber optic rotary connectors have been widely used and developed, especially dual-channel fiber optic rotary connectors. Existing dual-channel fiber optic rotary connectors often use dove prism structures, reflector structures, and lens structures.

[0003] The dual-channel fiber optic rotary connector with a dove prism structure uses the light transmission principle of the dove prism to achieve a 2:1 deceleration through a gear transmission mechanism, which offsets the 1:2 rotation ratio of the dove prism image and realizes multi-channel signal transmission at the stator end and the rotor end. Due to the existence of the mechanical structure, its adaptability in the space environment is poor and its reliability is low; and the environmental adaptability of the dove prism is poor. Under hot and humid conditions, condensation will occur on the surface of the dove prism, resulting in the failure of normal transmission of the optical signal. The dual-channel fiber optic rotary connector with a reflector structure uses a reflector to realize the steering of the light beam transmission. After multiple reflections, the light beam enters the receiving end to complete the signal transmission. This structure can select magnets or gears as the support of the reflector. However, due to the existence of the reflector structure, the transmission path of the multi-channel light beam is more complicated and the assembly difficulty is higher, resulting in partial light beam obstruction, which increases the insertion loss of the fiber optic rotary connection; at the same time, the magnet and gear structure will reduce the reliability of the fiber optic rotary connector and its environmental adaptability is poor. The dual-channel fiber optic rotary connector with a lens structure uses a Fresnel lens or a spherical lens structure to construct a passive symmetrical optical structure. Some optical devices at the transmitting end are placed off-axis and transmitted to the receiving end through the Fresnel lens or the spherical lens. However, the receiving end in this structure has poor ability to couple light beams, and requires high precision in processing and assembly. In addition, this structure mostly realizes unidirectional signal transmission and is difficult to achieve bidirectional transmission. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the existing dual-channel optical fiber rotary connector, such as poor environmental adaptability, high assembly difficulty, or difficulty in completing two-way signal transmission, and to provide a spatial dual-channel optical fiber rotary connector.

[0005] To achieve the above objectives, the technical solutions provided by the present invention are as follows:

[0006] A spatial dual-channel optical fiber rotary connector comprises a rotor sleeve and a stator shell respectively arranged at a rotor end and a stator end, the rotor sleeve and the stator shell are coaxially connected for rotation, and the special feature is that: it also comprises a first optical component for transmitting a first optical signal and a second optical component for transmitting a second optical signal; the first optical component comprises a first input component, a beam expansion component, a beam reduction component and a first output component sequentially arranged along the optical path; the first input component and the beam expansion component are arranged in the rotor sleeve, the first input component is used to couple the first optical signal and adjust it to match the diameter of the beam expansion component, the beam expansion component is used to expand and collimate a hollow light beam to form a collimated hollow light beam; the beam reduction component and the first output component are arranged in the stator shell, the collimated hollow light beam is shrunk by the beam reduction component, and then coupled and output by the first output component; the second optical component is arranged in the stator shell, comprises a second input component and a second output component coaxially arranged with the beam reduction component, and is used to transmit the second optical signal.

[0007] Further, the beam expansion assembly comprises a plano-concave lens and a plano-convex lens coaxially arranged in the rotor sleeve, the first input assembly comprises a first input optical fiber and a first gradient refractive index lens, and the first input optical fiber is a photonic crystal fiber;

[0008] The convex surface of the plano-convex lens is arranged opposite to the concave surface of the plano-concave lens; a first through hole is provided at the center of the plano-concave lens, and the first gradient refractive index lens is arranged in the first through hole;

[0009] One end of the first input optical fiber is connected to the incident end of the first gradient refractive index lens for transmitting the first optical signal, and the other end is connected to an external transmitting device. The first optical signal is transmitted from the first input optical fiber to the first gradient refractive index lens for beam expansion, and then reflected by the plano-convex lens and the plano-concave lens in turn to form a collimated hollow light beam.

[0010] Further, the beam expansion assembly comprises a plano-concave lens and a plano-convex lens coaxially arranged in the rotor sleeve, the first input assembly comprises a first input optical fiber and a first gradient refractive index lens, and the first input optical fiber is a multimode optical fiber;

[0011] The convex surface of the plano-convex lens is arranged opposite to the concave surface of the plano-concave lens; a first through hole is provided at the center of the plano-concave lens, and the first gradient refractive index lens is arranged in the first through hole;

[0012] One end of the first input optical fiber is connected to the incident end of the first gradient refractive index lens for transmitting the first optical signal, and the other end is connected to an external transmitting device;

[0013] An axicon lens group is also arranged between the first gradient refractive index lens and the plano-convex lens;

[0014] The first optical signal is transmitted from the first input optical fiber to the first gradient refractive index lens for beam expansion, and then forms a hollow light beam through the axicon lens group, and then is reflected by the plano-convex lens and the plano-concave lens in sequence to form a collimated hollow light beam.

[0015] Further, the beam reduction assembly includes a first meniscus lens, a second meniscus lens and a biconcave lens sequentially arranged along the optical path, and the first output assembly includes a second gradient refractive index lens and a first output optical fiber;

[0016] The first meniscus lens is arranged on the reflection light path of the plano-concave lens, the concave surfaces of the first meniscus lens and the second meniscus lens face the plano-concave lens, and the second gradient refractive index lens is located on the exit light path of the biconcave lens;

[0017] The output end of the second gradient refractive index lens is connected to one end of the first output optical fiber.

[0018] Further, the second input component includes a first fiber collimator and a second input fiber, and the input end of the first fiber collimator is connected to one end of the second input fiber for receiving the second optical signal;

[0019] The second output component includes a second fiber collimator and a second output fiber. The input end of the second fiber collimator corresponds to the output end of the first fiber collimator, and the output end is connected to one end of the second output fiber for outputting a second optical signal.

[0020] Furthermore, a first cavity and a second cavity which are connected are sequentially provided in the stator housing;

[0021] The rotor sleeve is nested in the stator housing and located in the first cavity, and is connected to the stator housing through a bearing assembly.

[0022] Furthermore, the stator housing is a cylindrical structure, and a stator end cover is provided at one end of the stator housing away from the first cavity;

[0023] The rotor sleeve is a cylindrical structure, and a rotor end cover is arranged at one end away from the second cavity;

[0024] A second through hole is provided at the center of the rotor end cover, and the incident end of the first gradient refractive index lens is embedded in the second through hole;

[0025] A third through hole is provided at the center of the stator end cover, and the other end of the first output optical fiber is arranged through the third through hole.

[0026] Further, the first output optical fiber is a multimode optical fiber;

[0027] The second input optical fiber and the second output optical fiber are both single-mode optical fibers.

[0028] Beneficial effects of the present invention:

[0029] 1. The two signal transmission channels formed in the present invention are coaxial transmission channels, which reduces the difficulty of assembly; the signals of both channels can realize bidirectional transmission, and the light beam of the external channel will not be blocked by the middle channel, which solves the problem of light beam blocking during coaxial transmission of multi-channel light beams, reduces the insertion loss of the external channel, and improves the overall performance of the optical fiber rotary connector.

[0030] 2. The present invention does not have mechanical transmission mechanisms such as gear mechanisms and magnets, so the difficulty of assembly is greatly reduced, which effectively increases the life of the optical fiber rotary connector and reduces the risk of the optical fiber rotary connector not working due to failure of the mechanical transmission mechanism. It has the characteristics of high reliability and strong environmental adaptability in space environments.

[0031] 3. The present invention expands the incident light beam of the Cassegrain beam expansion system through the first gradient refractive index lens, thereby expanding the range of the local hollow light beam. The Cassegrain beam expansion system has a simple structure, reduces the radial size of the coaxial transmission dual-channel optical fiber rotary connector, makes it easy to install and combine with a conductive slip ring to form an optoelectronic composite slip ring, and has a wider range of uses.

[0032] 4. The present invention generates a hollow light beam through a photonic crystal fiber, which reduces the requirements for the incident first signal light and has a wider range of applications. The hollow light beam is expanded by the first gradient refractive index lens to increase its central aperture, and then passes through the Cassegrain beam expansion system again, so that both the light spot and the central aperture are expanded, greatly reducing the shielding of the central channel on the external channel light beam.

[0033] 5. The space dual-channel optical fiber rotary connector of the present invention adopts high-precision self-lubricating ceramic ball bearings, which ensures the stability and reliability of optical signal transmission and has the characteristics of long life; the ceramic ball bearings are made of materials with little ion radiation influence and low condensable volatiles, which ensures that the optical fiber rotary connector is radiation-resistant, low-pollution, and has good spatial adaptability. At the same time, the space dual-channel optical fiber rotary connector of the present invention can also be used in radar or medical fields.

[0034] 6. The structure of the present invention is a passive setting, has strong anti-electromagnetic interference ability, and can be used in special environments or extreme environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a schematic structural diagram of an embodiment of the present invention;

[0036] Description of reference numerals:

[0037] 1-first input optical fiber, 2-plano-concave lens, 3-first gradient refractive index lens, 4-plano-convex lens, 5-first meniscus lens, 6-second meniscus lens, 7-biconcave lens, 8-second gradient refractive index lens, 9-first optical fiber collimator, 10-second optical fiber collimator, 11-second output optical fiber, 12-second input optical fiber, 13-statator housing, 14-ceramic ball bearing, 15-washer, 16-rotor sleeve, 17-rotor end cover, 18-support rod, 19-statator end cover, 20-first output optical fiber. DETAILED DESCRIPTION

[0038] The present invention provides a spatial dual-channel optical fiber rotary connector such as Figure 1 As shown, it includes a first optical component for transmitting a first optical signal and a second optical component for transmitting a second optical signal, as well as a rotor sleeve 16 arranged at a rotor end and a stator housing 13 arranged at a stator end.

[0039] The stator housing 13 and the rotor sleeve 16 are both cylindrical structures. A first cavity and a second cavity are connected in sequence in the stator housing 13. A stator end cover 19 is provided at one end of the stator housing 13 away from the first cavity. The rotor sleeve 16 is nested in the stator housing 13 and located in the first cavity. The rotor sleeve 16 is connected to the stator housing 13 through a bearing assembly. A rotor end cover 17 is provided at one end of the rotor sleeve 16 away from the second cavity. Figure 1 As shown, the bearing assembly is mainly composed of a ceramic ball bearing 14, a washer 15, and a retaining frame, and is a key component to ensure signal transmission and service life. In the present invention, the bearing assembly adopts non-metallic materials with low mass loss and low condensable volatility to reduce the pollution effect of condensable volatiles of non-metallic materials on the optical system. Among them, the bearing adopts a self-lubricating ceramic ball bearing 14, and the bearing retaining frame adopts a polyimide material, which greatly improves the service life from both material and structural aspects. At the same time, the first optical component and the second optical component of the present invention both adopt radiation-resistant optical glass, which effectively avoids the influence of space particle radiation.

[0040] The first optical component includes a first input component, a beam expansion component, a beam reduction component and a first output component which are arranged in sequence on the same optical axis. The first input component includes a first input optical fiber 1 and a first gradient refractive index lens 3. The incident end of the first gradient refractive index lens 3 is connected to one end of the first input optical fiber 1. The first input optical fiber 1 is a photonic crystal fiber, and the other end is connected to an external optical signal transmitting device for receiving an optical signal and converting it into a hollow light beam. The first gradient refractive index lens 3 expands the hollow light beam by gradient refractive index. The beam expansion component includes a plano-convex lens 4 and a plano-concave lens 2 which are arranged in sequence in the rotor sleeve 16 along the optical path. The plano-convex lens 4 is fixed in the rotor sleeve 16 by a support rod 18, and its convex surface is arranged opposite to the concave surface of the plano-concave lens 2. The plano-concave lens 2 is arranged close to the rotor end cover 17. The plano-concave lens 2 has a first through hole along the central axis, and a second through hole is arranged in the center of the rotor end cover 17. The first gradient refractive index lens 3 is arranged in the first through hole, and the incident end is embedded in the second through hole. The expanded hollow light beam is reflected by the plano-convex lens 4 and the plano-concave lens 2 in sequence to further expand the beam and form a collimated hollow light beam.

[0041] The plano-concave lens 2 and the plano-convex lens 4 form a Cassegrain beam expander system. The Cassegrain beam expander system has a simple and compact structure and can reduce the dispersion of light beam transmission and improve the coupling efficiency of the collimated hollow light beam. At the same time, the aperture size of the expanded hollow light beam can be adjusted according to the refractive index distribution and length of the first gradient refractive index lens 3, thereby reducing the obstruction of the light beam by the Cassegrain beam expander system.

[0042] The beam reduction assembly is arranged in the second cavity of the stator housing 13, and includes a first meniscus lens 5, a second meniscus lens 6, and a biconcave lens 7 arranged in sequence along the optical path. The first output assembly is arranged at an end of the second cavity away from the first cavity, and includes a second gradient refractive index lens 8 and a first output optical fiber 20.

[0043] The first meniscus lens 5 is arranged on the reflected light path of the plano-concave lens 2, the concave surfaces of the first meniscus lens 5 and the second meniscus lens 6 face the plano-concave lens 2, the second gradient refractive index lens 8 is located on the output light path of the biconcave lens 7 and at one end of the second cavity, the output end of the second gradient refractive index lens 8 is connected to one end of the first output optical fiber 20, the stator housing 13 is located at one end of the second cavity and a stator end cover 19 is arranged to seal the stator housing 13, a third through hole is provided in the center of the stator end cover 19, the other end of the first output optical fiber 20 is arranged through the third through hole for connecting to an external optical signal receiving device, in this embodiment, the first output optical fiber 20 is a multimode optical fiber. The collimated hollow light beam is subjected to the beam reduction assembly composed of the first meniscus lens 5, the second meniscus lens 6 and the biconcave lens 7 to achieve beam reduction and collimation, and then is incident into the gradient refractive index lens, and then coupled to the first output optical fiber 20 for output.

[0044] The present invention places the first meniscus lens 5 and the second meniscus lens 6 at the stator end, so that the collimated hollow light beam is contracted after reaching the stator end, reducing the influence of the position error of the first meniscus lens 5 and the second meniscus lens 6 on the contraction of the light beam during the rotation process. At the same time, the above optical axis, the central axis of the stator housing 13 and the central axis of the rotor sleeve 16 coincide. By selecting the refractive index distribution of the second gradient refractive index lens 8 and designing its length, the collimated hollow light beam after contraction can be efficiently coupled to the optical fiber, and the structure is simple, the cost is low, and the coupling efficiency is high.

[0045] The second optical component is arranged at the stator end, and includes a first fiber collimator 9 and a second fiber collimator 10 arranged in sequence along the optical path. The input end of the first fiber collimator 9 is connected to one end of the second input fiber 12, and the second optical signal is input through the second input fiber 12. The output end of the second fiber collimator 10 is connected to one end of the second output fiber 11, and the second optical signal is output through the second output fiber 11. Both the second input fiber 12 and the second output fiber 11 are single-mode fibers. Among them, the first fiber collimator 9 and the second input fiber 12 constitute the second input component, and the second fiber collimator 10 and the second output fiber 11 constitute the second output component.

[0046] The first meniscus lens 5 and the second meniscus lens 6 are respectively provided with mounting holes along the central axis, and the first optical fiber collimator 9 and the second optical fiber collimator 10 are respectively arranged at the mounting holes of the first meniscus lens 5 and the second meniscus lens 6. The second optical signal is transmitted from the second input optical fiber 12 to the first optical fiber collimator 9, and after collimation, is coupled to the second output optical fiber 11 through the second optical fiber collimator 10 to realize optical signal transmission.

[0047] In other embodiments of the present invention, the first input optical fiber 1 may also be a multimode optical fiber, and after the first optical signal is input, it is expanded by the first gradient index lens 3, and then a hollow light beam is generated by the axicon lens group, and then expanded by the plano-convex lens 4 and the plano-concave lens 2. At the same time, other transmission-type beam expansion systems may also be used to achieve beam expansion.

Claims

1. A spatial dual-channel optical fiber rotary connector, comprising a rotor sleeve (16) and a stator housing (13) respectively arranged at a rotor end and a stator end, wherein the rotor sleeve (16) and the stator housing (13) are coaxially rotatably connected, and characterized in that: Also included is a first optical component for transmitting the first optical signal and a second optical component for transmitting the second optical signal; The first optical component comprises a first input component, a beam expansion component, a beam reduction component and a first output component which are sequentially arranged along the optical path; The first input component and the beam expansion component are arranged in a rotor sleeve (16), the first input component is used to couple the first optical signal and adjust it to match the diameter of the beam expansion component, and the beam expansion component is used to expand and collimate the hollow light beam to form a collimated hollow light beam; The beam reduction component and the first output component are arranged in the stator housing (13); after the collimated hollow light beam is reduced by the beam reduction component, it is coupled and output by the first output component; The second optical component is arranged in the stator housing (13), and comprises a second input component and a second output component coaxially arranged with the beam reduction component, and is used for transmitting a second optical signal.

2. According to claim 1, a spatial dual-channel optical fiber rotary connector, characterized in that: The beam expansion component comprises a plano-concave lens (2) and a plano-convex lens (4) coaxially arranged in a rotor sleeve (16); the first input component comprises a first input optical fiber (1) and a first gradient refractive index lens (3); the first input optical fiber (1) is a photonic crystal optical fiber; The convex surface of the plano-convex lens (4) is arranged opposite to the concave surface of the plano-concave lens (2); a first through hole is provided at the center of the plano-concave lens (2), and the first gradient refractive index lens (3) is arranged in the first through hole; One end of the first input optical fiber (1) is connected to the incident end of the first gradient refractive index lens (3) for transmitting a first optical signal, and the other end is connected to an external transmitting device. The first optical signal is transmitted from the first input optical fiber (1) to the first gradient refractive index lens (3) for beam expansion, and then reflected by the plano-convex lens (4) and the plano-concave lens (2) in sequence to form a collimated hollow light beam.

3. According to claim 1, a spatial dual-channel optical fiber rotary connector, characterized in that: The beam expansion assembly comprises a plano-concave lens (2) and a plano-convex lens (4) coaxially arranged in a rotor sleeve (16); the first input assembly comprises a first input optical fiber (1) and a first gradient refractive index lens (3); the first input optical fiber (1) is a multimode optical fiber; The convex surface of the plano-convex lens (4) is arranged opposite to the concave surface of the plano-concave lens (2); a first through hole is provided at the center of the plano-concave lens (2), and the first gradient refractive index lens (3) is arranged in the first through hole; One end of the first input optical fiber (1) is connected to the incident end of the first gradient refractive index lens (3) for transmitting the first optical signal, and the other end is connected to an external transmitting device; An axicon lens group is also arranged between the first gradient refractive index lens (3) and the plano-convex lens (4); The first optical signal is transmitted from the first input optical fiber (1) to the first gradient refractive index lens (3) for beam expansion, and then passes through the axicon lens group to form a hollow light beam, and then is reflected in sequence by the plano-convex lens (4) and the plano-concave lens (2) to form a collimated hollow light beam.

4. A spatial dual-channel optical fiber rotary connector according to claim 2 or 3, characterized in that: The beam reduction assembly comprises a first meniscus lens (5), a second meniscus lens (6) and a biconcave lens (7) which are sequentially arranged along the optical path, and the first output assembly comprises a second gradient refractive index lens (8) and a first output optical fiber (20); The first meniscus lens (5) is arranged on the reflection light path of the plano-concave lens (2), the concave surfaces of the first meniscus lens (5) and the second meniscus lens (6) face the plano-concave lens (2), and the second gradient refractive index lens (8) is located on the exit light path of the biconcave lens (7); The output end of the second gradient refractive index lens (8) is connected to one end of the first output optical fiber (20).

5. A spatial dual-channel optical fiber rotary connector according to claim 4, characterized in that: The second input component comprises a first optical fiber collimator (9) and a second input optical fiber (12), wherein the input end of the first optical fiber collimator (9) is connected to one end of the second input optical fiber (12) for receiving a second optical signal; The second output component comprises a second optical fiber collimator (10) and a second output optical fiber (11); the input end of the second optical fiber collimator (10) corresponds to the output end of the first optical fiber collimator (9); the output end is connected to one end of the second output optical fiber (11) for outputting a second optical signal.

6. A spatial dual-channel optical fiber rotary connector according to claim 4, characterized in that: A first cavity and a second cavity that are connected are sequentially arranged in the stator housing (13); The rotor sleeve (16) is nested in the stator housing (13) and located in the first cavity, and is connected to the stator housing (13) via a bearing assembly.

7. A spatial dual-channel optical fiber rotary connector according to claim 6, characterized in that: The stator housing (13) is a cylindrical structure, and a stator end cover (19) is provided at one end of the stator housing (13) away from the first cavity; The rotor sleeve (16) is a cylindrical structure, and a rotor end cover (17) is arranged at one end away from the second cavity; A second through hole is provided at the center of the rotor end cover (17), and the incident end of the first gradient refractive index lens (3) is embedded in the second through hole; A third through hole is provided at the center of the stator end cover (19), and the other end of the first output optical fiber (20) is arranged through the third through hole.

8. The spatial dual-channel optical fiber rotary connector according to claim 7, characterized in that: The first output optical fiber (20) is a multimode optical fiber; The second input optical fiber (12) and the second output optical fiber (11) are both single-mode optical fibers.

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