Space laser communication receiving and transmitting coaxial self-calibration system

Abstract

The utility model provides a space laser communication receiving and transmitting coaxial self-calibration system. Comprising a dual-wavelength calibration laser, a first beam splitter, a second beam splitter, a first attenuator, a second attenuator, a third attenuator, a fourth attenuator, a first wavelength division multiplexer, a second wavelength division multiplexer, a third wavelength division multiplexer, a fourth wavelength division multiplexer, a first lambda 1 signal laser, a second lambda 1 signal laser and a first lambda 2 signal laser, a second lambda2 signal laser, a first optical transceiver module, a second optical transceiver module, a third optical transceiver module and a fourth optical transceiver module. According to the utility model, dual-wavelength calibration and transmit-receive isolation are used, the calibration capability of high precision and high reliability is realized, and a one-to-many self-calibration target can be realized; meanwhile, the system has the advantages of stray light prevention, backup calibration and the like, and can be widely applied to various satellite, airborne and other space laser communication links.

Description

Technical Field

[0001] The utility model relates to the technical field of measurement and testing, in particular to a coaxial self-calibration system for transmitting and receiving space laser communications. Background Art

[0002] In space laser communications, communication distances are extremely long. Even with highly directional lasers, the smallest beam divergence angles are magnified in space, making establishing optical communication links between satellites extremely difficult. Therefore, a mechanism is necessary to perform initial pointing, beacon acquisition, and target tracking. This is the PAT system, which aligns the transmit and receive beams and maintains stability throughout the communication process. The optical antenna transceiver system is a critical component of the PAT system and is extremely helpful for satellite optical communication systems.

[0003] With the rapid growth of satellite optical communication missions, the demand for communication performance continues to increase, and optical communication systems are placing increasingly stringent demands on the transceiver performance of optical antennas. Traditional optical system design in space optical communications has lagged behind the high performance demands placed on terminals. Because the operating environment of systems in space is complex, optical transceiver antennas can experience issues such as decreased received power and component misalignment due to factors such as vibration, temperature, vacuum, and radiation. To meet high-performance communication transmission requirements, the performance of the optical antenna transceiver system must be ensured. High-precision transceiver system coaxiality improves transmission energy utilization, thereby reducing bit error rates.

[0004] In long-distance space laser communications, even small deviations in the calibration of the transmit and receive beams can severely impact the efficiency and stability of the optical link. To improve the coaxiality of the transmit and receive beams, it is necessary to ensure the coaxiality of the pyramidal feedback beam with the transmitted beam, and the coaxiality of the pyramidal feedback beam with the received beam. The alignment accuracy between the two beams is the coaxial error. As part of the total alignment error, excessive coaxial error can lead to low received optical power, significant thermal noise, decreased communication speed, and increased bit error rate. Coaxial error is also a system error and can be eliminated through a closed-loop system.

[0005] Therefore, a cone calibration system for coaxial transmission and reception is needed. Summary of the Invention

[0006] The utility model aims to solve the problems of integration, volume and isolation of the coaxial self-calibration system for space laser communication, and provides a coaxial self-calibration system for transceiver in space laser communication. It uses dual-wavelength calibration and transceiver isolation, has high-precision and high-reliability calibration capabilities, and can achieve the "one-to-many" self-calibration goal; at the same time, it has the advantages of preventing stray light and backup calibration, and can be widely used in various types of satellite, airborne and other space laser communication links.

[0007] The utility model provides a space laser communication transceiver coaxial self-calibration system, comprising a dual-wavelength laser, a first attenuator optically connected to one output end of the dual-wavelength laser in sequence, a first wavelength division multiplexer, and a first optical transceiver module;

[0008] The first λ1 signal laser of the space laser communication system to be calibrated is optically connected to the input end of the first wavelength division multiplexer;

[0009] The first optical transceiver module includes an optical transceiver system located on the output optical path of the first wavelength division multiplexer, a cone located on the transmission optical path of the optical transceiver system, and a filter and a CMOS camera located in turn on the reflection optical path of the cone.

[0010] The dual-wavelength laser outputs a first calibration light with a wavelength of λ2, which reaches the first wavelength division multiplexer after passing through the first attenuator. The first calibration light is conjugated with the laser output by the first λ1 signal laser. The laser output by the first λ1 signal laser is used for laser link establishment and laser communication through the first optical transceiver module. The first calibration light is used for coaxial transceiver calibration.

[0011] The space laser communication transceiver coaxial self-calibration system described in the present invention is preferably configured such that the wavelength of the first calibration light is 808 nm, and the wavelength of the laser output by the first λ1 signal laser is 850 nm.

[0012] The space laser communication transceiver coaxial self-calibration system described in the utility model preferably further includes a second attenuator, a second wavelength division multiplexer, and a second optical transceiver module optically connected to the other output end of the dual-wavelength laser in sequence;

[0013] The first λ2 signal laser of the space laser communication system to be calibrated is optically connected to the input end of the second wavelength division multiplexer; the second optical transceiver module has the same structure as the first optical transceiver module;

[0014] The dual-wavelength laser outputs a second calibration light with a wavelength of λ1, which is output to the second wavelength division multiplexer through the second attenuator. The second calibration light is conjugated with the laser output by the first λ2 signal laser. The laser output by the first λ2 signal laser is used for laser link establishment and laser communication through the second optical transceiver module. The second calibration light is used for coaxial transceiver calibration.

[0015] The space laser communication transceiver coaxial self-calibration system described in the present invention is preferably configured such that the wavelength of the second calibration light is 850 nm, and the wavelength of the laser output by the first λ2 signal laser is 808 nm.

[0016] The space laser communication transceiver coaxial self-calibration system described in the present invention preferably further includes a first beam splitter connected between the output end of the dual-wavelength laser and the first attenuator, a second beam splitter connected between the output end of the dual-wavelength laser and the second attenuator, a third attenuator, a third wavelength division multiplexer, and a third optical transceiver module optically connected in sequence to the other output end of the first beam splitter, and a fourth attenuator, a fourth wavelength division multiplexer, and a fourth optical transceiver module optically connected in sequence to the other output end of the second beam splitter;

[0017] The second λ1 signal laser of the space laser communication system to be calibrated is optically connected to the input end of the third wavelength division multiplexer, and the second λ2 signal laser of the space laser communication system to be calibrated is optically connected to the input end of the fourth wavelength division multiplexer;

[0018] The third optical transceiver module and the fourth optical transceiver module have the same structure as the first optical transceiver module. The second λ1 signal laser and the first λ1 signal laser output lasers of the same wavelength, and the second λ2 signal laser and the first λ2 signal laser output lasers of the same wavelength.

[0019] The laser light output by the second λ1 signal laser is used for laser link establishment and laser communication through the third optical transceiver module, and the laser light output by the second λ2 signal laser is used for laser link establishment and laser communication through the fourth optical transceiver module.

[0020] The space laser communication transceiver coaxial self-calibration system described in the utility model is preferably configured such that the maximum output power of the dual-wavelength laser is 1 mW.

[0021] The utility model discloses a coaxial self-calibration system for transmitting and receiving space laser communications. As an optimal mode, the beam splitting ratios of the first beam splitter and the second beam splitter are both 50:50.

[0022] The utility model describes a space laser communication transceiver coaxial self-calibration system. As an optimal mode, the first attenuator, the second attenuator, the third attenuator and the fourth attenuator are all tunable mechanical attenuators with a tuning attenuation range of 5dBm to 40dBm.

[0023] The utility model describes a space laser communication transceiver coaxial self-calibration system. As an optimal mode, the first wavelength division multiplexer, the second wavelength division multiplexer, the third wavelength division multiplexer and the fourth wavelength division multiplexer are all WDMs with working bands λ1 and λ2.

[0024] The space laser communication transceiver coaxial self-calibration system described in the utility model is preferably configured such that the first optical transceiver module, the second optical transceiver module, the third optical transceiver module and the fourth optical transceiver module are all rear optical path transceiver modules;

[0025] The filters of the first optical transceiver module and the third optical transceiver module are both 808nm filters, and the filters of the second optical transceiver module and the fourth optical transceiver module are both 850nm filters.

[0026] The self-calibration system is a system that can perform high-precision and high-reliability self-calibration of multiple optical heads at the same time.

[0027] The dual-wavelength calibration laser is a miniaturized dual-wavelength laser with wavelengths of λ1 and λ2 and a maximum output power of 1mW.

[0028] The utility model provides a highly integrated, compact, and highly isolated coaxial self-calibration system for space laser communications, thereby overcoming the problems of insufficient energy for self-calibration of signal light and solving the problems of low transmit-receive isolation of optical systems.

[0029] The utility model has the following advantages:

[0030] (1) The present invention introduces a dual-wavelength laser into the laser communication optical system, providing a separate calibration light source for the cone self-calibration scheme, replacing the signal light beam method for cone self-calibration. The signal light beam emitted by the optical system is greatly attenuated after entering the receiving branch through cone reflection, and the receiving target surface can only receive weak signal light energy, which is not conducive to the coaxial self-calibration of the transmitter and receiver. If the emission energy of the signal light is increased, part of the signal light beam energy will not be reflected through the cone, and will directly enter the receiving target surface through the co-transmitting and receiving system, disrupting the normal cone self-calibration results.

[0031] Therefore, signal light self-calibration schemes require both increasing and decreasing emission energy, which presents limitations. The present invention provides a calibration light source (the wavelength of the calibration light and the wavelength of the signal emission light are mutually the transmit and receive wavelengths), using calibration light source calibration instead of signal light source calibration. Only low-power beam energy is required to enter the receiving branch target surface for calibration. At the same time, low-power light energy ensures high isolation of the transceiver system, realizing a lightweight, high-isolation corner self-calibration scheme.

[0032] (2) The utility model adopts a dual-wavelength laser, which can simultaneously perform angle cone calibration on multiple optical systems, making the entire machine compact and highly integrated.

[0033] (3) The present invention uses a signal laser, a calibration laser, and a wavelength division multiplexer to couple the different wavelength beams emitted by the two lasers into an optical system. This does not affect the normal signal transmission and reception of the laser terminal, while retaining the signal light cone self-calibration method. The laser terminal can be calibrated not only by the calibration light but also by the signal light, and has a cone calibration backup function, thereby improving the self-calibration reliability of the laser terminal. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a structural diagram of a coaxial self-calibration system for space laser communication transmission and reception;

[0035] Figure 2 Schematic diagram of a dual-wavelength laser for a coaxial self-calibration system for transceiver in space laser communication.

[0036] Reference numerals:

[0037] 1. Dual-wavelength laser; 2. First attenuator; 3. First wavelength division multiplexer; 4. First optical transceiver module; 41. Optical transceiver system; 42. Corner cone; 43. Filter; 44. CMOS camera; 5. Second attenuator; 6. Second wavelength division multiplexer; 7. Second optical transceiver module; 8. First beam splitter; 9. Second beam splitter; 10. Third attenuator; 11. Third wavelength division multiplexer; 12. Third optical transceiver module; 13. Fourth attenuator; 14. Fourth wavelength division multiplexer; 15. Fourth optical transceiver module; 21. First λ1 signal laser; 22. First λ2 signal laser; 23. Second λ1 signal laser; 24. Second λ2 signal laser. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0039] Example 1

[0040] like Figure 1 As shown, a space laser communication transceiver coaxial self-calibration system can simultaneously perform coaxial self-calibration on four sets of laser payloads, including a dual-wavelength calibration laser 1, a first beam splitter 8, a second beam splitter 9, a first attenuator 2, a second attenuator 5, a third attenuator 10, a fourth attenuator 13, a first wavelength division multiplexer 3, a second wavelength division multiplexer 6, a third wavelength division multiplexer 11, a fourth wavelength division multiplexer 14, a first λ1 signal laser 21, a second λ1 signal laser 21, a first λ2 signal laser 22, a second λ2 signal laser 24, a first optical transceiver module 4, a second optical transceiver module 7, a third optical transceiver module 12, and a fourth optical transceiver module 15. The optical transceiver module includes an optical transceiver system 41, a pyramid 42, a filter 43, and a CMOS camera 44.

[0041] The calibration method of the utility model is as follows: when the laser terminal performs self-calibration of the corner cone, the dual-wavelength laser is turned on and a calibration beam of a certain energy is emitted. The energy of the calibration beam is attenuated by the first beam splitter 8 and the first attenuator 2, and is coupled with the signal beam into the first optical transceiver module 4 using the first wavelength division multiplexer 3. The beam is reflected into the corner cone 42 through the optical transceiver system 41, and the reflected beam of the corner cone enters the CMOS camera 44 through the filter 43 for imaging. By analyzing the position error of the imaging light spot, the transceiver coaxiality is accurately calibrated.

[0042] Specifically, the laser terminal performs cone self-calibration. The dual-wavelength laser 1 emits a laser beam with a wavelength of 808 nm and a power of 0 dBm. After passing through a 50:50 first beam splitter 8 and a 10 dB first attenuator 2, the calibration beam energy is reduced to -13 dBm. This calibration beam, along with the signal light emitted by the 850 nm signal laser, is coupled into the first optical transceiver module 4 via a first wavelength division multiplexer 3. The 850 nm signal light passes through an optical transceiver system 41 for laser link establishment and laser communication. The 808 nm first calibration light is totally reflected by cone 42, passes through filter 43, and reaches a CMOS camera 44 for imaging. Calibration of the transceiver and transmitter coaxiality is performed based on the positional error of the imaging spot.

[0043] In this embodiment, the output power of the dual-wavelength laser 1 is 1 mW, and the wavelengths of the emitted light beams are 808 nm and 850 nm.

[0044] In this embodiment, the splitting ratio of the first beam splitter 8 and the second beam splitter 9 is 50:50.

[0045] In this embodiment, the attenuation range of the first attenuator 2 , the second attenuator 5 , the third attenuator 10 and the fourth attenuator 13 is 5 dB to 40 dB.

[0046] In this embodiment, the first wavelength division multiplexer 3, the second wavelength division multiplexer 6, the third wavelength division multiplexer 11 and the fourth wavelength division multiplexer 14 are reflective WDMs with an insertion loss of 3.3 dB.

[0047] In this embodiment, the first optical transceiver module 4 , the second optical transceiver module 7 , the third optical transceiver module 12 and the fourth optical transceiver module 15 are designed as a common-aperture transceiver system.

[0048] In this embodiment, the precision of the pyramid 42 is 5".

[0049] In this embodiment, the calibration light is 850 nm, the working wavelength of the optical path narrowband filter 43 is 850 nm±8 nm, T≥95%, and the cut-off depth OD7@808 nm±8 nm.

[0050] In this embodiment, the 850nm filter only allows the 850nm calibration light to pass through, blocking a small amount of 808nm signal light and other wavelengths reflected within the system, so that the 850nm light is stronger and can be used for calibration.

[0051] The above is only a preferred specific implementation method of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the present invention can make equivalent replacements or changes based on the technical solution and utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A coaxial self-calibration system for space laser communication transceivers, characterized by: It comprises a dual-wavelength laser (1), a first attenuator (2), a first wavelength division multiplexer (3), and a first optical transceiver module (4) optically connected to one output end of the dual-wavelength laser (1) in sequence; The first λ1 signal laser (21) of the space laser communication system to be calibrated is optically connected to the input end of the first wavelength division multiplexer (3); The first optical transceiver module (4) comprises an optical transceiver system (41) located on the output optical path of the first wavelength division multiplexer (3), a cone (42) located on the emission optical path of the optical transceiver system (41), and a filter (43) and a CMOS camera (44) located in sequence on the reflection optical path of the cone (42). The dual-wavelength laser (1) outputs a first calibration light having a wavelength of λ2, which reaches the first wavelength division multiplexer (3) through the first attenuator (2); the first calibration light is conjugated with the laser light output by the first λ1 signal laser (21); the laser light output by the first λ1 signal laser (21) is used for laser link establishment and laser communication through the first optical transceiver module (4); and the first calibration light is used for coaxial transceiver calibration.

2. A space laser communication transceiver coaxial self-calibration system according to claim 1, characterized in that: The wavelength of the first calibration light is 808 nm, and the wavelength of the laser output by the first λ1 signal laser (21) is 850 nm.

3. The space laser communication transceiver coaxial self-calibration system according to claim 1, characterized in that: It also includes a second attenuator (5), a second wavelength division multiplexer (6), and a second optical transceiver module (7) optically connected to the other output end of the dual-wavelength laser (1) in sequence; The first λ2 signal laser (22) of the space laser communication system to be calibrated is optically connected to the input end of the second wavelength division multiplexer (6); the second optical transceiver module (7) has the same structure as the first optical transceiver module (4); The dual-wavelength laser (1) outputs a second calibration light having a wavelength of λ1, which is output to the second wavelength division multiplexer (6) through the second attenuator (5); the second calibration light is conjugated with the laser light output by the first λ2 signal laser (22); the laser light output by the first λ2 signal laser (22) is used for laser link establishment and laser communication through the second optical transceiver module (7); and the second calibration light is used for coaxial transceiver calibration.

4. The space laser communication transceiver coaxial self-calibration system according to claim 3, characterized in that: The wavelength of the second calibration light is 850 nm, and the wavelength of the laser output by the first λ2 signal laser (22) is 808 nm.

5. The space laser communication transceiver coaxial self-calibration system according to claim 3, characterized in that: The invention also includes a first beam splitter (8) connected between the output end of the dual-wavelength laser (1) and the first attenuator (2), a second beam splitter (9) connected between the output end of the dual-wavelength laser (1) and the second attenuator (5), a third attenuator (10), a third wavelength division multiplexer (11), and a third optical transceiver module (12) optically connected in sequence to the other output end of the first beam splitter (8), and a fourth attenuator (13), a fourth wavelength division multiplexer (14), and a fourth optical transceiver module (15) optically connected in sequence to the other output end of the second beam splitter (9); The second λ1 signal laser (23) of the space laser communication system to be calibrated is optically connected to the input end of the third wavelength division multiplexer (11), and the second λ2 signal laser (24) of the space laser communication system to be calibrated is optically connected to the input end of the fourth wavelength division multiplexer (14); The third optical transceiver module (12) and the fourth optical transceiver module (15) have the same structure as the first optical transceiver module (4); the second λ1 signal laser (23) and the first λ1 signal laser (21) output lasers of the same wavelength; and the second λ2 signal laser (24) and the first λ2 signal laser (22) output lasers of the same wavelength. The lasers output by the two λ1 signal lasers (23) are used for laser link establishment and laser communication via the third optical transceiver module (12), and the lasers output by the two λ2 signal lasers (24) are used for laser link establishment and laser communication via the fourth optical transceiver module (15).

6. The space laser communication transceiver coaxial self-calibration system according to claim 1, characterized in that: The maximum output power of the dual-wavelength laser (1) is 1 mW.

7. The space laser communication transceiver coaxial self-calibration system according to claim 5, characterized in that: The beam splitting ratios of the first beam splitter (8) and the second beam splitter (9) are both 50:

50.

8. The space laser communication transceiver coaxial self-calibration system according to claim 5, characterized in that: The first attenuator (2), the second attenuator (5), the third attenuator (10) and the fourth attenuator (13) are all tunable mechanical attenuators with a tuning attenuation range of 5dBm to 40dBm.

9. The space laser communication transceiver coaxial self-calibration system according to claim 5, characterized in that: The first wavelength division multiplexer (3), the second wavelength division multiplexer (6), the third wavelength division multiplexer (11) and the fourth wavelength division multiplexer (14) are all WDMs with working bands λ1 and λ2.

10. The space laser communication transceiver coaxial self-calibration system according to claim 5, characterized in that: The first optical transceiver module (4), the second optical transceiver module (7), the third optical transceiver module (12) and the fourth optical transceiver module (15) are all rear optical path transceiver modules; The filters of the first optical transceiver module (4) and the third optical transceiver module (12) are both 808nm filters, and the filters of the second optical transceiver module (7) and the fourth optical transceiver module (15) are both 850nm filters.

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