CN-121984587-A - Star-earth laser communication atmosphere channel compensation system and method

Abstract

A star-to-ground laser communication atmosphere channel compensation system and method. Relates to the technical field of satellite-to-ground laser communication, in particular to a satellite-to-ground laser communication atmosphere channel compensation system and method. According to the invention, through structural coupling and parameter matching, the deep coordination of the multimode optical fiber and the MPLC is realized, and the optical signal coupling efficiency in a turbulent environment is obviously improved on the premise of reducing the complexity, the power consumption and the cost of the system. The system comprises a receiving module, a transmission connection module, a mode screening module and a MPLC optical mode demultiplexing module, wherein the receiving module captures and focuses multimode optical signals emitted by satellites to the transmission connection module through a coupling lens group, the transmission connection module receives and transmits the multimode optical signals to a multimode input end of an MPLC through a fiber core of a multimode optical fiber, and the mode screening module decomposes the multimode optical signals received by the multimode input end of the MPLC through the MPLC optical mode demultiplexing module to obtain fundamental modes of a plurality of modes and outputs the fundamental modes through an MPLC single-mode output end.

Inventors

• WANG XINGXING
• Geng Shengqiang
• DONG HUIBIN
• HUO ZHANWEI
• SUN WEI
• XING GUICHAO
• DAI LU

Assignees

• 长光卫星技术股份有限公司

Dates

Publication Date

20260505

Application Date

20260408

Claims (7)

1. 1. The star-to-ground laser communication atmosphere channel compensation system is characterized by comprising a coupling lens group (1), a multimode optical fiber (2), a flange (3), a multimode input end (4) of MPLC, an MPLC optical mode demultiplexing module (5) and an MPLC single-mode output end (6); the coupling lens group (1) captures and focuses multimode optical signals emitted by satellites on the fiber cores of the multimode optical fibers (2); the fiber core of the multimode optical fiber (2) receives and transmits multimode optical signals to the multimode input end (4) of the MPLC; the MPLC optical mode demultiplexing module (5) decomposes the multimode optical signals received by the multimode input end (4) of the MPLC to obtain the fundamental modes of a plurality of modes, and the fundamental modes are output through the MPLC single-mode output end (6).
2. 2. The atmospheric channel compensation system for satellite-to-ground laser communication according to claim 1, wherein the aperture of the output optical signal of the coupling lens group (1) is matched with the core of the multimode optical fiber (2), the receiving aperture of the coupling lens group (1) is 500mm, and the core diameter of the multimode optical fiber (2) is 50mm The core length of the multimode optical fiber (2) is 4m.
3. 3. A satellite-to-ground laser communication atmospheric channel compensation system according to claim 2, characterized in that the output end of the multimode optical fiber (2) and the multimode input end (4) of the MPLC are connected by means of a flange (3).
4. 4. A satellite-to-ground laser communication atmospheric channel compensation system according to claim 3, characterized in that the flange (3) is of the narrow key FC/APC type, the key gap of the flange (3) being 2.03mm.
5. 5. A satellite-to-ground laser communication atmospheric channel compensation system according to claim 4, characterized in that the numerical aperture of the multimode optical fiber (2) is 0.2 and the numerical aperture of the multimode input end (4) of the mplc is 0.22.
6. 6. A satellite-to-ground laser communication atmosphere channel compensation system according to claim 5, characterized in that the bending radius of the multimode optical fiber (2) is 。
7. 7. A method of atmospheric channel compensation for satellite-to-ground laser communication, the method being implemented by the system of any one of claims 1 to 6, the method comprising the steps of: s1, capturing and focusing free space laser signals emitted by satellites by a coupling lens group (1) to the fiber core of a multimode optical fiber (2); S2, the multimode optical fiber (2) transmits the received free space laser signal to the MPLC optical mode demultiplexing module (5) through the multimode input end (4) of the MPLC; s3, a MPLC optical mode demultiplexing module (5) decomposes signals received by a multi-mode input end (4) of the MPLC to obtain a plurality of modes of fundamental modes, and the fundamental modes are output through an MPLC single-mode output end (6).

Description

Star-earth laser communication atmosphere channel compensation system and method Technical Field The invention relates to the technical field of satellite-to-ground laser communication, in particular to a satellite-to-ground laser communication atmosphere channel compensation system and method. Background The satellite-to-ground laser communication is used as a core technology for breaking through the bottleneck of the traditional microwave communication capacity, and has become the optimal choice for satellite-to-ground large-capacity data transmission by virtue of the advantages of high transmission rate, repeated utilization of spectrum resources, high confidentiality and the like. However, when the free space optical signal passes through the atmospheric channel, the free space optical signal is inevitably influenced by atmospheric turbulence, so that optical field distortion and arrival angle fluctuation are caused, signal light is difficult to efficiently couple to the optical fiber, and the problems of signal power attenuation, flicker and the like are caused. Meanwhile, factors such as absorption and scattering of an optical signal by the atmosphere, laser emission loss and the like further exacerbate the problem of weak signal, and finally the error rate of a receiver is increased, so that the practical floor of the satellite-to-ground laser communication system is severely limited. In order to solve the technical bottleneck caused by the atmospheric channel, various compensation and coupling optimization schemes have been proposed in the industry, but certain defects exist, and the requirements of satellite-to-ground laser communication on low cost, low power consumption and high reliability are difficult to meet: (1) Schiavon M, vanzo A, campaci K, et al, in Multi-actuator LENS SYSTEMS for turbulence correction in free-space optical communication (Multi-actuator lens system for free-space optical communication turbulence correction) [ C ]// photonics MDPI, 2025, 12 (9): 870) propose an adaptive optical compensation technique, which, although adaptable to single-mode fiber devices, is complex in system, extremely high in cost and power consumption; (2) The research institute of China academy of sciences (institute of photoelectric technology) 2016's Shuoshi institute paper (research on control method for improving coupling efficiency of optical communication fibers, gan Xun, etc.), proposes a single mode fiber and Fast Steering Mirror (FSM) technology, however, the technology needs high-precision alignment, and is difficult to capture distorted light field energy; (3) The space diversity receiving technology is provided by arranging a plurality of groups of independent receiving antennas to form parallel channels, and can relieve turbulent multipath fading, but a plurality of sets of optical terminals and signal processing units are matched, so that the space occupation is large, the cost is high, and the multi-channel synchronous merging algorithm is complex. Furthermore, the related research also relates to an influence mechanism of atmospheric turbulence on satellite-ground laser communication. For example, yuan Renzhi, guo Jia, yao Haifeng and the like in a system of research status, key technology and future hope of satellite-to-ground fusion-oriented laser communication published in space-to-ground integrated information network (volume 5, 4, pages 34-42 of 2024), shen Lingjun and Song hero in three-layer transmission model numerical simulation of ground-star atmospheric turbulence path published in infrared and laser engineering (volume 52, 11, pages 265-277 of 2023) conduct numerical simulation research on an atmospheric turbulence transmission model; SONGHong-fei, CHEYing, ZHAOXin, LIPeng-fei and ZHOUJian-hong in Optics and Precision Engineering (optical and precision engineering) (2014, volume 22, 12 th edition, page 3205) published "Improvement of fiber coupling EFFICIENCY IN atmospheric turbulence (method of improving optical fiber coupling efficiency in atmospheric turbulence) discuss methods for improving optical fiber coupling efficiency. However, in-depth analysis, the above technical solution has long led to this field, and is derived from the long-established technical cognitive formulation and path dependence by those skilled in the art, and is embodied as a technical bias in the following two aspects: On the one hand, at the fiber-coupled device selection level, there is a path dependence on single-mode fibers and an inherent bias towards multimode fibers. From the technical evolution context, single-mode fibers are long regarded as the main choice of spatial optical coupling due to their high compatibility with existing optical communication devices, and the industry generally tends to compensate wavefront distortion caused by atmospheric turbulence to near the diffraction limit by complex means such as adaptive optics, and then couple into the single-mode fibers. However, the