Multi-node networking laser communication system

Abstract

The application belongs to the field of laser communication, and particularly relates to a multi-node networking laser communication system, which realizes signal light capture in a wide field of view through a super-wide-angle system, divides and images the light field to the focal plane of a DMD through a homogenizing system, controls the on-off state of the DMD micromirror through a dynamic adjustment system, thereby spatially gates the signal light in the target direction, and completes link establishment after collimation through a relay system; the transmission process is the reverse. The multi-node networking laser communication system realizes bidirectional functions of receiving and transmitting based on the same optical path, has the advantages of multi-target rapid inertia-free tracking, simplified system structure, strong spatial filtering capability, and low initial capture precision.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of laser communication, and particularly relates to a multi-node networking laser communication system. BACKGROUND

[0002] With the rapid iteration of information technology, the industry demand for Internet of Everything continues to rise, and the requirements for communication capacity, communication distance and communication rate in various fields of society show exponential growth. High-digital, high-quality and high-identification information transmission equipment has also emerged in large numbers. Under this background, laser communication has become the core and key technology supporting the next generation of satellite Internet, intelligent constellation and space information infrastructure, with its ultra-high transmission rate of Gbps or even Tbps.

[0003] With the deep evolution of space missions towards data-intensive, communication-networked and platform-miniaturized directions, emerging application scenarios such as low-orbit constellation systems, deep space exploration missions and on-orbit intelligent services have put forward rigorous requirements for the performance and functions of laser communication systems. Such requirements not only reflect the leap in the order of magnitude of transmission rate and network capacity, but also put forward overall improvement appeals for multi-dimensional indicators such as link adaptive capability, multi-node cooperative communication capability and high-stability control capability of laser communication systems in complex dynamic environments. Therefore, laser communication systems must have core technical foundations such as inter-satellite link (ISL) dynamic networking, multi-terminal cooperative communication and high-stability link control.

[0004] Currently, traditional laser communication systems generally adopt a point-to-point communication architecture, and each communication node needs to be independently configured with a complete set of transceiver terminals. In the beam alignment and tracking link, traditional systems mostly rely on mechanical APT (acquisition, pointing and tracking) systems, which have inherent defects such as large inertia and slow scanning speed, making it difficult to adapt to high-dynamic and multi-user networking communication scenarios.

[0005] At the same time, the point-to-point architecture design also leads to a series of chain problems: first, the system complexity and hardware cost are high, and when the number of networking nodes increases, each node needs to be equipped with independent optical transmitting / receiving equipment, supporting control systems and auxiliary equipment, greatly increasing the hardware deployment cost and later maintenance difficulty; second, the overall energy consumption of the system continues to rise, and independent equipment configuration requires each node to provide continuous and stable power supply, which puts a heavy burden on the energy supply system. SUMMARY

[0006] Therefore, the present application aims to provide a multi-node networking laser communication system to solve the technical problems of node complexity, high energy consumption and high alignment accuracy of existing laser communication systems in multi-node networking.

[0007] To achieve the above object, the technical scheme of the present application is implemented as follows:

[0008] A multi-node networking laser communication system comprises:

[0009] A super wide-angle system is used to realize a wide field of view coverage in a range of ±65°, and is used to receive signal light emitted by a target in the wide field of view when acting as a receiving end, and is used to emit signal light to the target in the wide field of view when acting as a transmitting end;

[0010] The front focal point of the homogenization system coincides with the rear focal point of the super wide-angle system, and is used to homogenize and spatially divide the received signal light when acting as a receiving end, and is used to combine and directionally guide the emitted signal light when acting as a transmitting end;

[0011] A spatial light modulation system is arranged on the focal plane of the homogenization system, and is used to spatially filter and field-gate the homogenized and spatially divided signal light when acting as a receiving end, and is used to reflect and directionally gate the emitted signal light when acting as a transmitting end;

[0012] A relay system, the front focal plane of the relay system is arranged with the spatial light modulation system, and the rear focal plane of the relay system is the exit pupil of the relay system, and is used to collimate the gated signal light when acting as a receiving end, and is used to relay the emitted signal light to the spatial light modulation system when acting as a transmitting end;

[0013] A coupling system, which is used to couple the collimated signal light of the relay system to a communication terminal when acting as a receiving end, and is used to couple the signal light emitted by the communication terminal to the relay system when acting as a transmitting end.

[0014] Further, the super wide-angle system comprises six lenses, which are respectively:

[0015] The first lens is a plano-concave lens, the optical aperture D1 is 76mm<D1<84mm, and the optical power Φ1 is -0.025<Φ1<-0.015;

[0016] The second lens is a meniscus lens, the optical aperture D2 is 26mm<D2<34mm, and the optical power Φ2 is -0.02<Φ2<-0.015;

[0017] The third lens is a meniscus lens, the optical aperture D3 is 20mm<D3<35mm, and the optical power Φ3 is -0.025<Φ3<-0.015;

[0018] The fourth lens is a biconvex lens, the optical aperture D4 is 25mm<D4<35mm, and the optical power Φ4 is 0.015<Φ4<0.025;

[0019] The fifth lens is a biconvex lens, the optical aperture D5 is 30mm < D5 < 40mm, and the optical power Φ5 is 0.01 < Φ5 < 0.02;

[0020] The sixth lens is a meniscus lens, the optical aperture D6 is 25mm < D6 < 35mm, and the optical power Φ6 is 0.01 < Φ6 < 0.02;

[0021] The center distance d1 between the first lens and the second lens is 65mm < d1 < 68mm;

[0022] The center distance d2 between the second lens and the third lens is 40mm < d2 < 42mm;

[0023] The center distance d3 between the third lens and the fourth lens is 6mm < d3 < 8mm;

[0024] The center distance d4 between the fourth lens and the fifth lens is 15mm < d4 < 17mm;

[0025] The center distance d5 between the fifth lens and the sixth lens is 10mm < d5 < 12mm.

[0026] Further, the light homogenizing system comprises a relay lens group and an imaging lens array; wherein,

[0027] The relay lens group comprises four lenses, which are respectively:

[0028] The seventh lens is a meniscus lens, the optical aperture D7 is 14mm < D7 < 18mm, and the optical power Φ7 is 0.015 < Φ7 < 0.025;

[0029] The eighth lens is a biconcave lens, the optical aperture D8 is 14mm < D8 < 18mm, and the optical power Φ8 is -0.05 < Φ8 < -0.04;

[0030] The ninth lens is a meniscus lens, the optical aperture D9 is 14mm < D9 < 18mm, and the optical power Φ9 is 0 < Φ9 < 0.01;

[0031] The tenth lens is a meniscus lens, the optical aperture D10 is 16mm < D10 < 20mm, and the optical power Φ10 is 0.01 < Φ10 < 0.02;

[0032] The imaging lens array comprises two lens groups arranged side by side, the optical parameters of the two lens groups are the same, each lens group comprises two lenses, which are respectively:

[0033] The eleventh lens is a meniscus lens, the optical aperture D11 is 5mm < D11 < 10mm, and the optical power Φ11 is 0.01 < Φ11 < 0.02;

[0034] The twelfth lens is a biconvex lens, the optical aperture D12 is 5mm < D12 < 10mm, and the optical power Φ12 is 0.05 < Φ12 < 0.06;

[0035] The center distance d6 between the seventh lens and the eighth lens is 10mm < d6 < 12mm;

[0036] The center distance d7 between the eighth lens and the ninth lens is 8mm < d7 < 10mm;

[0037] The center distance d8 between the ninth lens and the tenth lens is 7mm < d8 < 9mm;

[0038] The center distance d9 between the tenth lens and the eleventh lens is 16mm < d9 < 18mm;

[0039] The center distance d10 between the eleventh lens and the twelfth lens is 6mm < d10 < 8mm.

[0040] Further, the spatial light modulation system comprises a Digital Micromirror Device (DMD) and a dynamic adjustment system, and the dynamic adjustment system is used for adjusting the switching state of the micromirror array of the DMD in real time.

[0041] Further, the communication terminal comprises a tracking system, and the dynamic adjustment system drives the micromirror at the corresponding position on the DMD to switch to the on state according to the feedback signal provided by the tracking system.

[0042] Further, the relay system is an f-θ lens, and comprises four lenses, which are respectively:

[0043] The thirteenth lens is a plano-convex lens, the optical aperture D13 is 15mm < D13 < 20mm, and the optical power Φ13 is 0.01 < Φ13 < 0.02;

[0044] The fourteenth lens is a biconcave lens, the optical aperture D14 is 15mm < D14 < 20mm, and the optical power Φ14 is -0.02 < Φ14 < -0.01;

[0045] The fifteenth lens is a biconvex lens, the optical aperture D15 is 15mm < D15 < 20mm, and the optical power Φ15 is 0.01 < Φ15 < 0.02;

[0046] The sixteenth lens is a meniscus lens, the optical aperture D16 is 15mm < D16 < 20mm, and the optical power Φ16 is 0 < Φ16 < 0.01;

[0047] The center distance d11 between the thirteenth lens and the fourteenth lens is 1mm < d11 < 3mm;

[0048] The center interval d12 between the fourteenth lens and the fifteenth lens is 1mm < d12 < 3mm;

[0049] The center interval d13 between the fifteenth lens and the sixteenth lens is 1mm < d13 < 3mm.

[0050] Further, the multi-node networking laser communication system further comprises a TIR prism system between the light homogenizing system and the spatial light modulation system, for folding the homogenized and spatially segmented signal light and the emitted signal light.

[0051] Further, the TIR prism system comprises a first TIR prism and a second TIR prism, the first TIR prism comprises a surface a, a surface b and a surface c, the second TIR prism comprises a surface d, a surface e and a surface f, the surface b is a side surface of the surface a and the surface c, the surface c is cemented with the surface d, the signal light realizes total reflection at the surface d, and the angle satisfies θr > arcsin 1 / n, wherein θr is an included angle between an optical axis of the signal light incident to the surface d and a normal line of the surface d, and n is a refractive index of the second TIR prism.

[0052] Further, the number of the coupling systems is at least one.

[0053] Further, the number of the coupling systems is two, each coupling system comprises a plane mirror, a half-mirror, a first converging lens and a second converging lens, the selected and collimated signal light is reflected to the half-mirror through the plane mirror, the half-mirror reflects a part of the light to the first converging lens, the light is incident to one communication terminal through the converging of the first converging lens, and the half-mirror also transmits another part of the light to the second converging lens, and the light is incident to another communication terminal through the converging of the second converging lens.

[0054] Compared with the prior art, the application can achieve the following beneficial effects:

[0055] 1. The application realizes wide field of view coverage by using an ultra-wide-angle system, and combines the high-speed switching capability of a DMD to quickly select and track multiple targets in the full field of view without any mechanical movement, thereby completely eliminating the time delay of mechanical scanning, improving the system response speed and reconfiguration capability by orders of magnitude, and perfectly adapting to high dynamic, multi-node spatial networking scenarios.

[0056] 2. The application uses the light path reversibility principle, and the multi-node networking laser communication system can be used as a receiving end and a transmitting end, without the need to configure multiple independent transceiver devices, thereby greatly reducing the number of hardware devices, significantly reducing the volume, weight, power consumption and manufacturing cost of the system, and providing feasibility for large-scale constellation system deployment.

[0057] 3、The present application establishes the accurate mapping of the spatial angle-DMD pixel group through the homogenization system, and then uses the DMD for spatial gating. This not only allows the multi-node networking laser communication system to selectively establish a link with a target in a specific direction, but more importantly, can directly eliminate background light and interference in the optical physics level, greatly improving the signal-to-noise ratio of the multi-node networking laser communication system. At the same time, the architecture of the multi-node networking laser communication system supports independent and parallel gating control of multiple discrete targets in a large field of view, laying the foundation for true multi-target simultaneous communication, thereby improving the spectral utilization and overall communication capacity of the system.

[0058] 4、The ultra-wide-angle system of the present application realizes instantaneous global coverage of a large field of view through special anti-telephoto optical design, which expands the instantaneous search range of the spatial signal. This design directly reduces the requirement for the initial pointing accuracy of the multi-node networking laser communication system, so that multiple light signals in an uncertain area can be captured at one time without the need for slow scanning of the traditional mechanical APT system, significantly reducing the time required for the first capture of the light signal and improving the link establishment efficiency of the multi-node networking laser communication system in a complex dynamic space environment.

[0059] 5、The front focal point of the homogenization system precisely coincides with the rear focal point of the ultra-wide-angle system, and the imaging lens array of the homogenization system maps the incident light beams of different directions to different positions on the DMD focal plane, realizing the homogenization and equal division of the light beams. This design not only guarantees the uniformity of the signals from all directions, but also realizes the spatial separation of the signals from all directions through beam partitioning, preventing signal aliasing, and ensuring the stability and reliability of the communication link through real-time feedback regulation of the dynamic adjustment system, meeting the demand for high data transmission quality in space tasks. BRIEF DESCRIPTION OF DRAWINGS

[0060] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated in and constitute a part of this application. The embodiments of the application illustrated in the drawings, and their description, are presented to add generic structure for public understanding of the application. In the drawings:

[0061] Figure 1 The structure diagram of the multi-node networking laser communication system described in the embodiments of the present application;

[0062] Figure 2 The structure diagram of the ultra-wide-angle system described in the embodiments of the present application;

[0063] Figure 3 The schematic diagram of the homogenization system described in the embodiments of the present application;

[0064] Figure 4 The field of view segmentation principle diagram of the DMD described in the embodiments of the present application;

[0065] Figure 5 Structure diagram of f-θ lens according to the present application.

[0066] Legend: super wide-angle system 1, first lens 11, second lens 12, third lens 13, fourth lens 14, fifth lens 15, sixth lens 16, homogenization system 2, relay lens group 21, seventh lens 211, eighth lens 212, ninth lens 213, tenth lens 214, imaging lens array 22, eleventh lens 221, twelfth lens 222, TIR prism system 3, first TIR prism 31, second TIR prism 32, spatial light modulation system 4, DMD 41, dynamic adjustment system 42, relay system 5, thirteenth lens 51, fourteenth lens 52, fifteenth lens 53, sixteenth lens 54, coupling system 6, plane mirror 61, half-mirror 62, first converging lens 63, second converging lens 64, communication terminal 7. DETAILED DESCRIPTION

[0067] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not constitute a limitation on the present application.

[0068] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0069] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" and the like are only used for description purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited by "first", "second" and the like can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0070] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "assembly", "connection", "linkage" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0071] The present application will be described in detail below with reference to Figures 1-5 and in conjunction with the embodiments.

[0072] As Figure 1 shown, the embodiment of the present application provides a multi-node networking laser communication system, which can be used as a receiving end and a transmitting end. When used as a receiving end, it is used for receiving signal light transmitted by a target; when used as a transmitting end, it is used for transmitting signal light to a target.

[0073] The multi-node networking laser communication system comprises an ultra-wide-angle system 1, a homogenization system 2, a TIR prism system 3, a spatial light modulation system 4, a relay system 5 and a coupling system; wherein the ultra-wide-angle system 1 is used to realize a wide field of view coverage within ±65°, and when the ultra-wide-angle system 1 is used as a receiving end, it is used to receive signal light transmitted by a target within the wide field of view, and when the ultra-wide-angle system 1 is used as a transmitting end, it is used to transmit signal light to a target within the wide field of view; the front focal point of the homogenization system 2 coincides with the rear focal point of the ultra-wide-angle system 1, and when the homogenization system 2 is used as a receiving end, it is used to homogenize and spatially segment the received signal light to form an image, and when the homogenization system 2 is used as a transmitting end, it is used to combine and directionally guide the transmitted signal light; when the TIR prism system 3 is used as a receiving end, it is used to turn the homogenized and spatially segmented signal light, and when the TIR prism system 3 is used as a transmitting end, it is used to fold the transmitted signal light; the spatial light modulation system 4 is arranged on the focal plane of the homogenization system 2, and when the spatial light modulation system 4 is used as a receiving end, it is used to spatially filter and field-gate the homogenized and spatially segmented signal light, and when the spatial light modulation system 4 is used as a transmitting end, it is used to reflect and directionally gate the transmitted signal light; the front focal plane of the relay system 5 is arranged with the spatial light modulation system 4, and the rear focal plane of the relay system 5 is the exit pupil of the relay system 5, and when the relay system 5 is used as a receiving end, it is used to collimate the gated signal light, and when the relay system 5 is used as a transmitting end, it is used to relay the transmitted signal light to the spatial light modulation system 4; and when the coupling system 6 is used as a receiving end, it is used to couple the collimated signal light from the relay system 5 to a communication terminal 7, and when the coupling system 6 is used as a transmitting end, it is used to couple the signal light transmitted by the communication terminal 7 to the relay system 5.

[0074] The following will take the multi-node networking laser communication system as an example to illustrate the composition of each system in detail.

[0075] The ultra-wide-angle system as the optical antenna of the multi-node networking laser communication system has the core function of realizing the instantaneous global capture of each signal light in the range of ±65° large field of view. The ultra-wide-angle system 1 is an image telecentric system, which can better transfer the light beam. The ultra-wide-angle system 1 projects all potential signal lights in the large field of view into the homogenization system 2 in parallel through special reverse telephoto optical design. As shown in Figure 2 The ultra-wide-angle system 1 includes six lenses, which are a first lens 11, a second lens 12, a third lens 13, a fourth lens 14, a fifth lens 15 and a sixth lens 16 arranged in sequence. The first lens 11 is a plano-concave lens, the optical aperture D1 is 76mm<D1<84mm, and the optical power Φ1 is -0.025<Φ1<-0.015. The second lens 12 is a meniscus lens, the optical aperture D2 is 26mm<D2<34mm, and the optical power Φ2 is -0.02<Φ2<-0.015. The third lens 13 is a meniscus lens, the optical aperture D3 is 20mm<D3<35mm, and the optical power Φ3 is -0.025<Φ3<-0.015. The fourth lens 14 is a double convex lens, the optical aperture D4 is 25mm<D4<35mm, and the optical power Φ4 is 0.015<Φ4<0.025. The fifth lens 15 is a double convex lens, the optical aperture D5 is 30mm<D5<40mm, and the optical power Φ5 is 0.01<Φ5<0.02. The sixth lens 16 is a meniscus lens, the optical aperture D6 is 25mm<D6<35mm, and the optical power Φ6 is 0.01<Φ6<0.02. The center distance d1 between the first lens 11 and the second lens 12 is 65mm<d1<68mm. The center distance d2 between the second lens 12 and the third lens 13 is 40mm<d2<42mm. The center distance d3 between the third lens 13 and the fourth lens 14 is 6mm<d3<8mm. The center distance d4 between the fourth lens 14 and the fifth lens 15 is 15mm<d4<17mm. The center distance d5 between the fifth lens 15 and the sixth lens 16 is 10mm<d5<12mm.

[0076] The reverse telephoto design of the ultra-wide-angle system 1 is to realize the compression of the large field of view angle by using the first lens 11, the second lens 12 and the third lens 13 with negative optical power, and to realize the convergence of the light beam into an image by using the fourth lens 14, the fifth lens 15 and the sixth lens 16 with positive optical power.

[0077] The homogenization system 2 homogenizes the light signal received by the ultra-wide-angle system 1, and divides the homogenized light signal into equal parts to image onto the focal plane of the DMD, providing panoramic light field information for subsequent digital signal processing and spatial filtering, thereby completely eliminating the time delay introduced by traditional mechanical scanning. As shown in Figure 3As shown, the light homogenizing system 2 includes a relay lens group 21 and an imaging lens array 22. The relay lens group 21 is a telecentric system on the object side, and receives the light beam of the super-wide-angle system 1. The imaging lens array 22 is a telecentric system on the image side, and realizes field sharing.

[0078] The relay lens group 21 includes four lenses, i.e., a seventh lens 211, an eighth lens 212, a ninth lens 213, and a tenth lens 214. The seventh lens 211 is a meniscus lens, with an optical aperture D7 of 14mm < D7 < 18mm and an optical power Φ7 of 0.015 < Φ7 < 0.025. The eighth lens 212 is a double-concave lens, with an optical aperture D8 of 14mm < D8 < 18mm and an optical power Φ8 of -0.05 < Φ8 < -0.04. The ninth lens 213 is a meniscus lens, with an optical aperture D9 of 14mm < D9 < 18mm and an optical power Φ9 of 0 < Φ9 < 0.01. The tenth lens 214 is a meniscus lens, with an optical aperture D10 of 16mm < D10 < 20mm and an optical power Φ10 of 0.01 < Φ10 < 0.02. The center-to-center distance d6 between the seventh lens 211 and the eighth lens 212 is 10mm < d6 < 12mm. The center-to-center distance d7 between the eighth lens 212 and the ninth lens 213 is 8mm < d7 < 10mm. The center-to-center distance d8 between the ninth lens 213 and the tenth lens 214 is 7mm < d8 < 9mm.

[0079] The imaging lens array 22 includes two lens groups arranged side by side, and the two lens groups have the same optical parameters. Each lens group includes two lenses, i.e., an eleventh lens 221 and a twelfth lens 222. The eleventh lens 221 is a meniscus lens, with an optical aperture D11 of 5mm < D11 < 10mm and an optical power Φ11 of 0.01 < Φ11 < 0.02. The twelfth lens 222 is a double-convex lens, with an optical aperture D12 of 5mm < D12 < 10mm and an optical power Φ12 of 0.05 < Φ12 < 0.06. The center-to-center distance d9 between the tenth lens 214 and the eleventh lens 221 is 16mm < d9 < 18mm. The center-to-center distance d10 between the eleventh lens 221 and the twelfth lens 222 is 6mm < d10 < 8mm.

[0080] As shown in FIG. 2, the super-wide-angle system 1 includes a lens group 11 and a light homogenizing system 2. Figure 1As shown, the TIR prism system 3 includes a first TIR prism 31 and a second TIR prism 32. The first TIR prism 31 includes surface a, surface b, and surface c, where surface b is the side surface of surfaces a and c. Surface a serves as the incident surface of the first TIR prism 31, and surface c serves as the exit surface of the first TIR prism 31. The second TIR prism 32 includes surface d, surface e, and surface f. Surface c is bonded to surface d. Surface d serves as both the incident and reflecting surface of the second TIR prism 32, surface e serves as both the exit and incident surface of the second TIR prism 32, and surface f serves as the exit surface of the second TIR prism 32. The signal light emitted from the homogenizing system 2 enters the TIR prism system 3 through surface a, passes through surfaces c, d, and e in sequence, and then illuminates the working area of ​​DMD41. The selected signal light is reflected by DMD41, passes through surface e, and is incident on surface d. After total internal reflection on surface d, it exits from surface e and is incident on the relay system 5. The angle at which the beam is totally internally reflected on surface d satisfies θr > arcsin1 / n, where θr is the angle between the optical axis of the signal light incident on surface d and the normal to surface d, and n is the refractive index of the second TIR prism.

[0081] like Figure 1 As shown, the spatial light modulation system 4 includes a DMD41 and a dynamic adjustment system 42. The working area of ​​the DMD41 is divided into different sub-regions according to the beam partitioning of the homogenizing system 2. Each sub-region corresponds to the global field of view of the ultra-wide-angle system 1, and can modulate the signal light within the global field of view to achieve parallel sampling of the signal light. The dynamic adjustment system 42 is used to adjust the on / off state of the micromirror array of the DMD41 in real time. The signal light is imaged on the focal plane of the DMD41. By controlling the on / off state of the micromirror array through the dynamic adjustment system 42, a programmable spatial filter is formed, which adjusts only the micromirrors corresponding to the signal light in the target direction to the on state and reflects them to the subsequent relay system 5, thereby achieving background light suppression and target light selection in the spatial domain. The dynamic adjustment system 42 sends a pulse signal to the micromirror array. When the pulse signal is high, it controls the micromirrors to flip to a positive angle and be in an open state. The signal light is reflected to the relay system 5. When the pulse signal is low, it controls the micromirrors to flip to a negative angle and be in an closed state. The signal light is deflected to the absorption area or a non-working path, thereby achieving spatial gating of the target beam and thus achieving field selection.

[0082] Ultra-wide-angle system 1 receives signals from spatial directions The light rays are collected and converged by the homogenization system 2 and form corresponding light spots on the focal plane of the homogenization system 2. The front focal point of the homogenization system 2 is exactly overlapped with the back focal point of the ultra-wide-angle system 1 to ensure that the incident light energy from different directions collected and converged by the homogenization system 2 is received by the subsequent system without vignetting. The ultra-wide-angle system 1 converts the incident light beams of specific directions into convergent spherical wavefronts and focuses on the back focal plane of the ultra-wide-angle system 1. The relay lens group 21 located at the front end of the homogenization system 2 converts the incident light beams into angular parallel light; in the imaging lens array 22 located at the rear end of the homogenization system 2, each lens acts as an independent optical channel and only receives and processes the local wavefront information corresponding to its sub-lens channel, and converges the light beams to different positions on the focal plane of the homogenization system 2 according to the incident angle. For single-beam incidence, the focal spot energy is collected by multiple lenses of the imaging lens array 22 at the same time, and each lens forms a light spot on the focal plane; for multiple beams of incident light of different angles, multiple separate light spots are formed, and each lens converges multiple light spots corresponding to the incident angle on the focal plane at the same time.

[0083] The homogenization system 2 can be regarded as a kind of spatial light field shaping element. In the structure of the imaging lens array 22, each lens corresponds to a sub-lens, and its function can be represented by a ray tracing model as follows:

[0084] ;

[0085] Wherein, M represents the spatial mapping matrix of the homogenization system 2, which is used to describe the geometric transformation relationship between the incident light field and the image plane light field; represents the spatial position coordinates of the light ray on the entrance plane when the light ray enters the homogenization system 2; represents the direction angle of the light ray when the light ray enters the homogenization system 2, i.e. the incident angle of the light ray in x and y directions; represents the spatial position coordinates of the light ray on the focal plane after the light ray passes through the homogenization system 2; represents the exit direction angle of the light ray after the light ray passes through the homogenization system 2, i.e. the exit angle of the light ray in x and y directions.

[0086] For an ideal imaging lens array 22:

[0087] ;

[0088] Wherein, is the focal length of the lens. The matrix represents the following transformation relationship:

[0089]

[0090] The above transformation relationship shows that the light beams of each incident angle are mapped to different focal plane positions after the homogenization system 2, realizing field sharing.

[0091] DMD41 is located on the focal plane of the homogenizing system 2, and the incident light beams of different incident directions are simultaneously imaged onto the focal plane of the DMD41, realizing parallel sampling of spatial signals.

[0092] Each micromirror on the DMD41 has a center coordinate When the size of the micromirror is much smaller than the scale of the focal plane, it can be approximated that the micromirror represents a small field of view unit on the focal plane. Therefore, the micromirror array of the DMD41 is equivalent to pixelizing the entire field of view of the ultra-wide-angle system 1. By controlling the algorithm to identify the position of the target light spot, and setting the corresponding micromirror pixel group to the open state, while setting all other micromirrors to the closed state, only allowing the light beam from the target direction to enter the subsequent optical path, thereby achieving strong background light suppression and multi-target selection ability in space.

[0093] As Figure 4 shown, the field of view segmentation principle of the DMD41 is as follows:

[0094] Figure 4 (a) and (b) in FIG. 1 respectively show the on-off state of the micromirror, which is controlled by the dynamic adjustment system 42. The on-off state of the micromirror is represented as:

[0095] ;

[0096] The reflection function of the DMD is defined as:

[0097] ;

[0098] where d is the size of a single micromirror, and the rectangular function is

[0099] The output field after the ultra-wide-angle system 1, the homogenizing system 2, and the DMD41 is :

[0100] .

[0101] That is, the light beam is both spatially separated and shared by the homogenizing system 2, and is directionally reflected and selected by the DMD41.

[0102] ​The light beam reflected by the DMD41 in the on state is divergent. Therefore, a relay system 5 (the DMD is located on the front focal plane of the relay system 5, and the exit pupil of the relay system 5 is located on the rear focal plane of the relay system 5) is required to receive and re-collimate this light beam. The relay system 5 has two key functions: one is image transfer: relaying the modulation plane of the DMD41 to the exit pupil plane of the system; the other is beam collimation: converting the spherical wavefront from a specific pixel of the DMD41 into a plane wave to form a collimated light beam pointing in a specific direction. The direction of this outgoing light beam is uniquely determined by the coordinates of the activated micromirror cluster on the DMD41.

[0103] The relay system is an f-θ lens. The f-θ lens is an object-space telecentric system that converts the divergent light beam reflected by the DMD41 in the on state into a parallel light beam. As Figure 5 shown, the f-θ lens includes four lenses, namely the thirteenth lens 51, the fourteenth lens 52, the fifteenth lens 53, and the sixteenth lens 54. The thirteenth lens 51 is a plano-convex lens with an optical aperture D13 of 15mm < D13 < 20mm and a focal power Φ13 of 0.01 < Φ13 < 0.02; the fourteenth lens 52 is a biconcave lens with an optical aperture D14 of 15mm < D14 < 20mm and a focal power Φ14 of -0.02 < Φ14 < -0.01; the fifteenth lens 53 is a biconvex lens with an optical aperture D15 of 15mm < D15 < 20mm and a focal power Φ15 of 0.01 < Φ15 < 0.02; the sixteenth lens 54 is a meniscus lens with an optical aperture D16 of 15mm < D16 < 20mm and a focal power Φ16 of 0 < Φ16 < 0.01; the central interval d11 between the thirteenth lens 51 and the fourteenth lens 52 is 1mm < d11 < 3mm; the central interval d12 between the fourteenth lens 52 and the fifteenth lens 53 is 1mm < d12 < 3mm; the central interval d13 between the fifteenth lens 53 and the sixteenth lens 54 is 1mm < d13 < 3mm.

[0104] The number of coupling systems 6 is at least one. Figure 1 The case where the number of coupling systems 6 is two is shown. Each coupling system 6 respectively includes a plane mirror 61, a semi-transmissive semi-reflective mirror 62, a first converging lens 63, and a second converging lens 64. The selected and collimated signal light is reflected by the plane mirror 61 to the semi-transmissive semi-reflective mirror 62. The semi-transmissive semi-reflective mirror 62 reflects a part of the light to the first converging lens 63, and the light converges through the first converging lens 63 and is incident on a communication terminal 7. The semi-transmissive semi-reflective mirror 62 also transmits another part of the light to the second converging lens 64, and the light converges through the second converging lens 64 and is incident on another communication terminal 7.

[0105] In one example of the present application, the two communication terminals 7 are respectively a tracking system and a laser signal processing system, the dynamic adjustment system 42 drives the micro-mirror at the corresponding position on the DMD 41 to the open state according to the feedback signal provided by the tracking system, and the laser signal processing system is used for modulation, demodulation and codec processing of the signal light, to realize the conversion and transmission of information.

[0106] The above describes in detail the working process and principle of the multi-node networking laser communication system as a transmitting end. According to the optical path reversibility principle, when the multi-node networking laser communication system is a receiving end, it is just the opposite of the transmitting end, and the specific process is as follows:

[0107] Signal input: the signal light is coupled into the coupling system 6 by the communication terminal 7, forming a collimated light.

[0108] Into the relay system: the collimated light is emitted from the back focal plane (exit pupil plane) of the relay system 5.

[0109] DMD 41 selective reflection: according to the optical path reversibility, this beam of collimated light converges to a certain specific position of the front focal plane (i.e. DMD 41) of the relay system 5. This position is determined by the incident angle of the collimated light.

[0110] Through the dynamic adjustment system 42, only the micro-mirror area corresponding to the target transmission direction on the DMD 41 is set to the open state, and all other areas of the micro-mirror are in the off state. Therefore, the converging light will only be reflected by the micro-mirror in the target area, and the light irradiated to the off state area will be guided away from the main light path.

[0111] Into the light homogenization system 2: the reflected light selected by the DMD 41 enters the light homogenization system 2. At this time, the function of the light homogenization system 2 changes from light splitting imaging to beam combining and directing.

[0112] Since the micro-mirror on the DMD 41 is located in a specific sub-area, the reflected light will mainly enter the corresponding sub-lens channel of the imaging lens array 22. The sub-lens collimates the light beam and projects it to the spatial direction corresponding to the sub-lens channel.

[0113] Ultra-wide-angle system 1 emission: the light beam after beam combining and directing by the light homogenization system 2 is finally emitted to the remote target through the ultra-wide-angle system 1. The ultra-wide-angle system 1 functions as a transmitting antenna, and due to its large field of view characteristics, it can well cover the possible area of the target.

[0114] It should be understood that the above-mentioned various forms of processes can be reordered, added or deleted. For example, the steps described in the present disclosure can be executed in parallel, in sequence or in different orders, as long as the desired results of the technical solutions of the present disclosure can be achieved, which are not limited herein.

[0115] The foregoing detailed description has set forth various embodiments of the devices and / or processes via the use of specific terminology. However, embodiments thereof can be practiced with the exact description not being presented in detail. The term "device" should be understood to encompass devices operating in various modes, such as active mode, sleep mode, hibernate mode, and the like. The terms "coupled" and "connected," along with their derivatives, can be used. It should be understood that these terms are not intended as synonyms for each other. Rather, particular circuitry that can be said to be coupled or connected can be coupled and connected via some transmission medium. Furthermore, when used in the detailed description, the terms "coupled" and "connected," along with their derivatives, can be used. It should be understood that these terms are not intended as synonyms for each other. Rather, particular

Claims

1. A multi-node networking laser communication system, characterized by, The application relates to a communication system, which comprises the following components: a super wide-angle system, which is used for realizing wide field of view coverage in a range of +65 degrees, and is used for receiving signal light emitted by a target in a wide field of view when serving as a receiving end and for emitting signal light to the target in the wide field of view when serving as a transmitting end; a front focal point of a homogenizing system is coincident with a rear focal point of the super wide-angle system, which is used for homogenizing and spatially dividing the received signal light when serving as the receiving end and for beam combining and directional guiding of the emitted signal light when serving as the transmitting end; a spatial light modulation system, which is arranged on a focal plane of the homogenizing system, is used for spatially filtering and field of view gating of the homogenized and spatially divided signal light when serving as the receiving end and for reflecting direction gating of the emitted signal light when serving as the transmitting end; the spatial light modulation system comprises a digital micro-mirror device and a dynamic adjustment system, and the dynamic adjustment system is used for real-time adjustment of switch states of a micro-mirror array of the digital micro-mirror device; a relay system, a front focal plane of the relay system is arranged with the spatial light modulation system, and a rear focal plane of the relay system is an exit pupil of the relay system, which is used for collimating the gated signal light when serving as the receiving end and for relaying the emitted signal light to the spatial light modulation system when serving as the transmitting end; a coupling system, which is used for coupling the collimated signal light of the relay system to a communication terminal when serving as the receiving end and for coupling signal light emitted by the communication terminal to the relay system when serving as the transmitting end; the communication terminal comprises a tracking system, and the dynamic adjustment system drives micro-mirrors at corresponding positions on the digital micro-mirror device to switch to an open state according to a feedback signal provided by the tracking system.

2. The multi-node networking laser communication system of claim 1, wherein, The super wide-angle system comprises six lenses, which are respectively: a first lens, which is a plano-concave lens, has an optical aperture D1 of 76mm < D1 < 84mm and an optical power Phi1 of -0.025 < Phi1 < -0.015; a second lens, which is a meniscus lens, has an optical aperture D2 of 26mm < D2 < 34mm and an optical power Phi2 of -0.02 < Phi2 < -0.015; a third lens, which is a meniscus lens, has an optical aperture D3 of 20mm < D3 < 35mm and an optical power Phi3 of -0.025 < Phi3 < -0.015; a fourth lens, which is a double convex lens, has an optical aperture D4 of 25mm < D4 < 35mm and an optical power Phi4 of 0.015 < Phi4 < 0.025; a fifth lens, which is a double convex lens, has an optical aperture D5 of 30mm < D5 < 40mm and an optical power Phi5 of 0.01 < Phi5 < 0.02; a sixth lens, which is a meniscus lens, has an optical aperture D6 of 25mm < D6 < 35mm and an optical power Phi6 of 0.01 < Phi6 < 0.02; a center interval d1 of the first lens and the second lens is 65mm < d1 < 68mm; a center interval d2 of the second lens and the third lens is 40mm < d2 < 42mm; a center interval d3 of the third lens and the fourth lens is 6mm < d3 < 8mm; a center interval d4 of the fourth lens and the fifth lens is 15mm < d4 < 17mm; a center interval d5 of the fifth lens and the sixth lens is 10mm < d5 < 12mm.

3. The multi-node networking laser communication system of claim 1, wherein, The homogenizing system comprises a relay lens group and an imaging lens array; wherein, The relay lens group comprises four lenses, which are respectively: The seventh lens is a meniscus lens, the optical aperture D7 is 14mm<D7<18mm, and the optical power Φ7 is 0.015<Φ7<0.025; The eighth lens is a double concave lens, the optical aperture D8 is 14mm<D8<18mm, and the optical power Φ8 is -0.05<Φ8<-0.04; The ninth lens is a meniscus lens, the optical aperture D9 is 14mm<D9<18mm, and the optical power Φ9 is 0<Φ9<0.01; The tenth lens is a meniscus lens, the optical aperture D10 is 16mm<D10<20mm, and the optical power Φ10 is 0.01<Φ10<0.02; The imaging lens array comprises two lens groups arranged side by side, the optical parameters of the two lens groups are the same, and each lens group comprises two lenses, which are respectively: The eleventh lens is a meniscus lens, the optical aperture D11 is 5mm<D11<10mm, and the optical power Φ11 is 0.01<Φ11<0.02; The twelfth lens is a double convex lens, the optical aperture D12 is 5mm<D12<10mm, and the optical power Φ12 is 0.05<Φ12<0.06; The center distance d6 between the seventh lens and the eighth lens is 10mm<d6<12mm; The center distance d7 between the eighth lens and the ninth lens is 8mm<d7<10mm; The center distance d8 between the ninth lens and the tenth lens is 7mm<d8<9mm; The center distance d9 between the tenth lens and the eleventh lens is 16mm<d9<18mm; The center distance d10 between the eleventh lens and the twelfth lens is 6mm<d10<8mm.

4. The multi-node networking laser communication system of claim 1, wherein, The relay system is an f-θ lens, which comprises four lenses, which are respectively: The thirteenth lens is a plano-convex lens, the optical aperture D13 is 15mm<D13<20mm, and the optical power Φ13 is 0.01<Φ13<0.02; The fourteenth lens is a double concave lens, the optical aperture D14 is 15mm<D14<20mm, and the optical power Φ14 is -0.02<Φ14<-0.01; The fifteenth lens is a double convex lens, the optical aperture D15 is 15mm<D15<20mm, and the optical power Φ15 is 0.01<Φ15<0.02; The sixteenth lens is a meniscus lens, the optical aperture D16 is 15mm<D16<20mm, and the optical power Φ16 is 0<Φ16<0.01; The center distance d11 between the thirteenth lens and the fourteenth lens is 1mm<d11<3mm; The center distance d12 between the fourteenth lens and the fifteenth lens is 1mm<d12<3mm; The center distance d13 between the fifteenth lens and the sixteenth lens is 1mm<d13<3mm.

5. The multi-node networking laser communication system of claim 1, wherein, A TIR prism system is further arranged between the homogenization system and the spatial light modulation system, and is used for folding the homogenized and spatially divided signal light and the emitted signal light.

6. The multi-node networking laser communication system of claim 5, wherein, The TIR prism system comprises a first TIR prism and a second TIR prism, the first TIR prism comprises a surface a, a surface b and a surface c, the second TIR prism comprises a surface d, a surface e and a surface f, the surface b is a side surface of the surface a and the surface c, the surface c is cemented with the surface d, total reflection of signal light is realized on the surface d, and an angle satisfies θr>arcsin1 / n, wherein θr is an included angle between an optical axis of the signal light incident to the surface d and a normal line of the surface d, and n is a refractive index of the second TIR prism.

7. The multi-node networking laser communication system of claim 1, wherein, The number of coupling systems is at least one.

8. The multi-node networking laser communication system of claim 7, wherein, The number of coupling systems is two, each coupling system comprises a plane mirror, a half-mirror, a first converging lens and a second converging lens, the selected and collimated signal light is reflected to the half-mirror through the plane mirror, the half-mirror reflects part of the light to the first converging lens, the light is incident to one communication terminal through the converging of the first converging lens, and the half-mirror also transmits another part of the light to the second converging lens, the light is incident to another communication terminal through the converging of the second converging lens.

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