Rear-intercept-adjustable optical fiber nutation coupling system suitable for wide-temperature ground environment

Abstract

The invention relates to a rear-intercept-adjustable optical fiber nutation coupling system suitable for a ground wide-temperature environment, relates to the technical field of space optical communication, and solves the problem that in the prior art, focal length change and rear-intercept change of a coupling lens caused by environment temperature change cannot be dynamically corrected in real time; the back intercept cannot be actively adjusted; and the axial error cannot be inhibited. The optical fiber nutation coupling system comprises a substrate, an optical fiber, a precision displacement mechanism, an optical fiber seat, a light shield, a coupling lens group, a narrow-band filter lens group, a fast reflecting mirror seat, a fast reflecting mirror, a reflecting mirror and a light beam reflex lens group. According to the optical fiber nutation coupling system with the adjustable rear intercept suitable for the ground wide-temperature environment, large-stroke and high-bandwidth real-time dynamic correction can be carried out on axial deviation and radial deviation at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of space optical communication, and in particular to an optical fiber nutation coupling system with adjustable back intercept suitable for a wide temperature environment on the ground. Background Art

[0002] Compared with microwave communication, laser communication has the advantages of fast speed, low power consumption, high confidentiality, and strong anti-interference. It is a key technology to achieve integrated space-ground-air interconnection. In particular, the planning of the State Grid project and the accelerated pace of the construction of the global Internet satellite constellation have made space optical communication a research hotspot. The efficient optical fiber coupling technology is one of the key problems of the current space optical communication system. Only by accurately coupling the space light into the optical fiber can stable communication be achieved. The optical fiber nutation coupling system is a new coupling method developed in recent years, which can effectively compensate for platform vibration, atmospheric turbulence and temperature changes.

[0003] Traditional fiber nutation coupling systems, such as those disclosed in Chinese patent documents CN110601756B, CN110632714B, CN109560878B, CN114928405B and CN115291331B, only use a single piezoelectric fast mirror to perform real-time closed-loop control of the fiber power, which can only suppress the radial deviation of the light beam, but cannot perform real-time dynamic correction for the change in the focal length and back intercept of the coupling lens caused by the change in ambient temperature, which can easily lead to a decrease in coupling efficiency and an increase in the bit error rate. In view of the strict temperature control environment between satellites, Chinese patent application CN117811659A further proposed an axial deviation correction system based on thermal control on the basis of the above patent tilt control, but this method can only adjust the focal length of the lens, but cannot actively adjust the back intercept, and the axial deviation correction range is extremely small, which cannot be applied to the wide temperature environment on the ground where the temperature changes by 50°C. Meanwhile, the method for adjusting axial deviation based on thermal control disclosed in Chinese patent application CN117811659A has a low correction frequency and cannot suppress axial errors with high-frequency characteristics such as turbulence, vibration and temperature. Summary of the invention

[0004] The present invention aims to solve the technical problems in the prior art that the focal length change and back intercept change of the coupling lens caused by the ambient temperature change cannot be corrected in real time, the back intercept cannot be actively adjusted, and the axial error cannot be suppressed, and provide a fiber nutation coupling system with adjustable back intercept suitable for a wide temperature environment on the ground.

[0005] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0006] A fiber nutation coupling system with adjustable back intercept suitable for wide temperature environment on the ground, comprising: a substrate, an optical fiber, a precision displacement mechanism, an optical fiber seat, a light shield, a coupling lens group, a narrow-band filter group, a quick-reflection mirror seat, a quick-reflection mirror, a reflector and a beam deflection mirror group; wherein the beam deflection mirror group, the quick-reflection mirror seat, the narrow-band filter group, the coupling lens group and the precision displacement mechanism are arranged on the substrate in sequence in the direction of the light path; the quick-reflection mirror seat is provided with a quick-reflection mirror; the front end of the quick-reflection mirror is a reflector; the optical fiber seat is arranged on the precision displacement mechanism; the front end of the optical fiber seat is provided with a light shield, and the rear end is connected to the end face of the optical fiber;

[0007] The precision displacement mechanism is used for adjusting the axial position deviation; the fast reflection mirror is a two-dimensional angle adjustment mechanism;

[0008] During spatial optical coupling, the parallel light is reflected by the beam deflecting mirror group and reaches the reflector. After being reflected again, it is transmitted through the narrow-band filter group and the coupling lens group and focused in the middle of the optical fiber end face. After entering the optical fiber, most of it enters the communication terminal for signal demodulation, and a small part enters the power detector for real-time closed loop of the precision displacement mechanism and the fast reflection mirror.

[0009] In the above technical solution, the optical fiber is a multimode optical fiber, a single-mode optical fiber or a single-mode polarization-maintaining optical fiber.

[0010] In the above technical solution, the precision displacement mechanism is a transmission mechanism including a stepping motor, a reducer and a ball screw.

[0011] In the above technical solution, the precision displacement mechanism has a stroke of ±2 mm.

[0012] In the above technical solution, the narrowband filter group allows light near the communication band to pass through and cuts off lasers of other wavelengths.

[0013] In the above technical solution, the fast reflection mirror is a piezoelectric ceramic fast reflection mirror or a voice coil type fast reflection mirror.

[0014] The present invention has the following beneficial effects:

[0015] The optical fiber nutation coupling system with adjustable back intercept and applicable to a wide temperature environment on the ground can simultaneously perform real-time dynamic correction of axial deviation and radial deviation with a large stroke and high bandwidth.

[0016] The optical fiber nutation coupling system with adjustable back intercept suitable for a wide temperature environment on the ground of the present invention introduces a precise displacement mechanism so that the optical fiber back intercept of the system can be actively and quickly adjusted within a large travel range, and can effectively correct the axial deviation under large temperature changes, and is suitable for a wide temperature environment on the ground.

[0017] The optical fiber nutation coupling system with adjustable back intercept suitable for wide temperature environment on the ground adopts a servo mechanism instead of a thermal control compensation method, and has the advantages of high correction frequency, high rigidity, high repeatability and the like.

[0018] The optical fiber nutation coupling system with adjustable back intercept suitable for wide temperature environment on the ground has been applied to the satellite-to-ground laser communication ground station system working in the wide temperature environment of -30℃ to +55℃ on the ground, and has achieved good practical effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0020] Figure 1 The structure diagram of the optical fiber nutation coupling system with adjustable back intercept applicable to a wide temperature environment on the ground according to the present invention.

[0021] The reference numerals in the figures indicate:

[0022] 1-substrate; 2-optical fiber; 3-precision displacement mechanism; 4-optical fiber holder; 5-light shield; 6-coupling lens group; 7-narrow band filter group; 8-fast mirror holder; 9-fast mirror; 10-reflecting mirror; 11-beam deflecting mirror group. DETAILED DESCRIPTION

[0023] The inventive concept of the present invention is:

[0024] The optical fiber nutation coupling system with adjustable back intercept suitable for wide temperature environment on the ground of the present invention independently places the optical fiber on a high-rigidity, large-stroke precision displacement mechanism, and forms a three-dimensional real-time closed-loop adjustment mechanism with a fast reflection mirror, which can simultaneously perform high-frequency dynamic correction of axial and radial deviations.

[0025] The present invention is described in detail below with reference to the accompanying drawings.

[0026] The following is combined with Figure 1 The implementation of the technical solution is further described in detail to more clearly illustrate the characteristics of the present invention, but this cannot be used to limit the protection scope of the present invention. Any optical fiber nutation coupling system that realizes optical fiber axial position deviation correction based on a displacement mechanism belongs to the protection scope of the present invention.

[0027] The optical fiber nutation coupling system with adjustable back intercept applicable to a wide temperature environment on the ground of the present invention has strong versatility and can be used in coherent light or incoherent light communication systems. This embodiment is applied to the OOK communication system.

[0028] The optical fiber nutation coupling system with adjustable back intercept and applicable to a wide temperature environment on the ground of the present invention comprises: a substrate 1, an optical fiber 2, a precision displacement mechanism 3, an optical fiber seat 4, a light shield 5, a coupling lens group 6, a narrow-band filter group 7, a quick-reflection mirror seat 8, a quick-reflection mirror 9, a reflector 10 and a beam deflection mirror group 11. The beam deflection mirror group 11, the quick-reflection mirror seat 8, the narrow-band filter group 7, the coupling lens group 6 and the precision displacement mechanism 3 are arranged on the substrate 1 in sequence in the direction of the optical path; the quick-reflection mirror seat 8 is provided with a quick-reflection mirror 9; the front end of the quick-reflection mirror 9 is a reflector 10; the optical fiber seat 4 is arranged on the precision displacement mechanism 3; the front end of the optical fiber seat 4 is provided with a light shield 5, and the rear end is connected to the end face of the optical fiber 2.

[0029] The spatial optical coupling path of the optical fiber nutation coupling system with adjustable back intercept suitable for a wide temperature environment on the ground of the present invention is as follows: the parallel light is reflected by the beam deflection mirror group 11, reaches the reflector 10, is reflected again, is transmitted through the narrowband filter group 7 and the coupling lens group 6, and is focused at the center of the end face of the optical fiber 2.

[0030] After the spatial light is coupled into the optical fiber 2 , most of it enters the communication terminal for signal demodulation, and a small part enters the power detector for real-time closed loop of the precision displacement mechanism 3 and the fast reflection mirror 9 .

[0031] The optical fiber 2 is a multimode optical fiber; in other specific embodiments, the optical fiber 2 may also be a single-mode optical fiber or a single-mode polarization-maintaining optical fiber.

[0032] The precision displacement mechanism 3 is a transmission mechanism including a stepping motor, a reducer and a ball screw, and performs position feedback based on a grating, and has high positioning accuracy and repeatability.

[0033] The precision displacement mechanism 3 has high rigidity and a control bandwidth of about 100 Hz, and can quickly and in real time correct high-frequency axial errors caused by turbulence, vibration, temperature, etc.

[0034] The precision displacement mechanism 3 has a travel range of ±2 mm, which can meet the requirements of adjusting the axial position deviation caused by a wide temperature environment on the ground.

[0035] The narrowband filter group 7 only allows light near the communication band to pass through, while lasers of other wavelengths are cut off. In this embodiment, the narrowband filter group 7 only allows lasers near the 1550nm band to pass through, while lasers of other wavelengths are cut off.

[0036] The fast mirror 9 is a two-dimensional angle adjustment mechanism, which can be a piezoelectric ceramic fast mirror or a voice coil fast mirror, etc., and has a high control bandwidth. In this embodiment, the fast mirror 9 is a piezoelectric ceramic fast mirror, which can adjust the two-dimensional rotation angle of the mirror 10 and has a control bandwidth of about 1600 Hz.

[0037] The core of the fiber nutation coupling system with adjustable back intercept suitable for wide temperature environment on the ground of the present invention is that the axial deviation is corrected by the precision displacement mechanism 3, the radial deviation is corrected by the fast reflection mirror 9, and the three-dimensional mechanism performs real-time rapid search, so that the real-time power reaching the power detector tends to be maximum.

[0038] The optical fiber nutation coupling system with adjustable back intercept and applicable to a wide temperature environment on the ground can simultaneously perform real-time dynamic correction of axial deviation and radial deviation with a large stroke and high bandwidth.

[0039] The optical fiber nutation coupling system with adjustable back intercept suitable for a wide temperature environment on the ground of the present invention introduces a precise displacement mechanism so that the optical fiber back intercept of the system can be actively and quickly adjusted within a large travel range, and can effectively correct the axial deviation under large temperature changes, and is suitable for a wide temperature environment on the ground.

[0040] The optical fiber nutation coupling system with adjustable back intercept suitable for wide temperature environment on the ground adopts a servo mechanism instead of a thermal control compensation method, and has the advantages of high correction frequency, high rigidity, high repeatability and the like.

[0041] The optical fiber nutation coupling system with adjustable back intercept suitable for wide temperature environment on the ground has been applied to the satellite-to-ground laser communication ground station system working in the wide temperature environment of -30℃ to +55℃ on the ground, and has achieved good practical effect.

[0042] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A fiber nutation coupling system with adjustable back intercept suitable for wide temperature environment on the ground, characterized in that: include: A substrate (1), an optical fiber (2), a precision displacement mechanism (3), an optical fiber seat (4), a light shield (5), a coupling lens group (6), a narrow-band filter group (7), a quick-reflection mirror seat (8), a quick-reflection mirror (9), a reflector (10) and a light beam deflection mirror group (11); wherein the light beam deflection mirror group (11), the quick-reflection mirror seat (8), the narrow-band filter group (7), the coupling lens group (6) and the precision displacement mechanism (3) are arranged in sequence on the substrate (1) in the direction of the optical path; a quick-reflection mirror (9) is arranged on the quick-reflection mirror seat (8); the front end of the quick-reflection mirror (9) is a reflector (10); the optical fiber seat (4) is arranged on the precision displacement mechanism (3); a light shield (5) is arranged on the front end of the optical fiber seat (4), and the rear end is connected to the end face of the optical fiber (2); The precision displacement mechanism (3) is used for adjusting the axial position deviation; the fast reflection mirror (9) is a two-dimensional angle adjustment mechanism; During spatial optical coupling, the parallel light is reflected by the beam deflection mirror group (11) and reaches the reflector (10). After being reflected again, it is transmitted through the narrow-band filter group (7) and the coupling lens group (6) and focused at the center of the end face of the optical fiber (2). After entering the optical fiber (2), most of the light enters the communication terminal for signal demodulation, and a small part enters the power detector for real-time closed loop of the precision displacement mechanism (3) and the fast reflection mirror (9).

2. The optical fiber nutation coupling system with adjustable back intercept suitable for wide temperature environment on the ground according to claim 1, characterized in that: The optical fiber (2) is a multimode optical fiber, a single-mode optical fiber or a single-mode polarization-maintaining optical fiber.

3. The optical fiber nutation coupling system with adjustable back intercept suitable for wide temperature environment on the ground according to claim 1, characterized in that: The precision displacement mechanism (3) is a transmission mechanism comprising a stepping motor, a reducer and a ball screw.

4. The optical fiber nutation coupling system with adjustable back intercept suitable for a wide temperature environment on the ground according to claim 3, characterized in that: The precision displacement mechanism (3) has a travel range of ±2 mm.

5. The optical fiber nutation coupling system with adjustable back intercept suitable for wide temperature environment on the ground according to claim 1, characterized in that: The narrowband filter group (7) allows light near the communication band to pass through and cuts off laser light of other wavelengths.

6. The optical fiber nutation coupling system with adjustable back intercept suitable for wide temperature environment on the ground according to claim 1, characterized in that: The fast reflection mirror (9) is a piezoelectric ceramic fast reflection mirror or a voice coil type fast reflection mirror.

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