Laser radar networking system

Abstract

The invention relates to a laser radar networking system. The system comprises a laser and an optical antenna network (7), the laser is formed by sequentially connecting a signal generation module (1), a pre-amplification module (2), a hybrid beam combination main amplification module (3), a transmitting and receiving module (4), a coherent detection module (5) and a signal processing module (6), and the optical antenna network (7) comprises a plurality of optical antennas; the hybrid beam combining main amplification module (3) comprises a pump laser (3-1), a hollow-core solid hybrid beam combiner (3-2) and a hollow-core optical fiber (3-3), and the transmitting and receiving module (4) comprises a hollow-core solid hybrid circulator (4-1) and a hollow-core optical fiber optical switch (4-2).

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser radar, in particular to a laser radar networking system. BACKGROUND

[0002] With the rapid development and large-scale promotion of wind power, meteorology, low-altitude economy and other fields, the market has higher requirements for the detection capability of laser radars, and it is urgent to realize global monitoring with large range and high precision. For example, in the field of wind power, the global wind conditions of tens of square kilometers need to be monitored to optimize the scheduling of wind turbines; in the field of meteorology, the changes of cross-regional meteorological elements need to be tracked to improve the accuracy of prediction and early warning; in the field of low-altitude economy, the safety state of a large piece of airspace needs to be evaluated to ensure the smoothness of the route.

[0003] The detection distance range of a single laser radar is limited, which is difficult to meet such global monitoring requirements, so the laser radar networking system emerges as the times require. The laser radar networking system deploys multiple laser radar nodes, and realizes the cooperative work of devices through transmission links to build a global detection network. Compared with a single laser radar, the laser radar networking system can realize global blind area detection, real-time data interaction and synchronous analysis.

[0004] However, the traditional laser radar generally uses solid quartz glass optical fiber for light pulse transmission, and this scheme has obvious technical bottlenecks. The use of traditional solid optical fiber for long-distance transmission of high-power laser will cause serious nonlinear effects, so the nonlinear effects will limit the single pulse energy, thereby causing the signal transmission distance to be limited or the detection distance range of a single radar to be limited. This makes the coverage range of the traditional laser radar networking system usually limited to within 5 kilometers. If the coverage area is expanded, a large number of relay devices need to be additionally added, which not only increases the deployment cost, but also may bring additional workload to the data synchronization of networking, which seriously restricts the large-scale application and practical value of the laser radar networking system.

[0005] In view of the above problems, the related technology needs to be improved. SUMMARY

[0006] Therefore, it is necessary to provide a laser radar networking system aiming at the above technical problems.

[0007] A laser radar networking system, the system comprising a laser and an optical antenna network (7), the laser being composed of a signal generation module (1), a pre-amplification module (2), a hybrid beam combining main amplification module (3), a transmitting and receiving module (4), a coherent detection module (5), a signal processing module (6) connected in sequence, and the optical antenna network (7) comprising a plurality of optical antennas;

[0008] The signal generation module (1) is configured to output signal light and reference light;

[0009] The pre-amplification module (2) comprises a solid core fiber amplifier for amplifying the signal light to obtain pre-amplified signal light;

[0010] The mixed-beam main amplification module (3) comprises a pump laser (3-1), an air-core solid mixed-beam combiner (3-2), and an air-core fiber (3-3). The pump laser (3-1) is configured to output pump light. The air-core solid mixed-beam combiner (3-2) is configured to couple the pre-amplified signal light and the pump light. The air-core fiber (3-3) is configured to amplify the pre-amplified signal light to obtain twice-amplified signal light.

[0011] The transmitting and receiving module (4) comprises an air-core solid mixed circulator (4-1) and an air-core fiber optical switch (4-2). The air-core solid mixed circulator (4-1) comprises a first port, a second port, and a third port. The first port is configured to receive the twice-amplified signal light and transmit the twice-amplified signal light to the air-core fiber optical switch (4-2) through the second port. The air-core fiber optical switch (4-2) is connected to the optical antenna network (7). The third port is connected to the coherent detection module (5).

[0012] The coherent detection module (5) is configured to receive the echo signal, mix the echo signal with reference light, and convert the echo signal into an electrical signal.

[0013] The signal processing module (6) is configured to process the electrical signal to obtain target object information.

[0014] In one embodiment, the air-core solid mixed-beam combiner (3-2) comprises:

[0015] An input fiber port (3-2-1) comprising a signal input fiber interface and a pump input fiber interface;

[0016] A solid core lead-in section (3-2-2) connected to the signal input fiber interface, wherein the core of the solid core lead-in section (3-2-2) is of a solid structure;

[0017] A gradual transition section (3-2-3) connected to the solid core lead-in section (3-2-2), wherein the core of the gradual transition section (3-2-3) gradually transitions from a solid structure to an air-core structure, and the mode field linearly expands from a single mode field to a large mode field;

[0018] An air-core stabilization section (3-2-4) connected to the gradual transition section (3-2-3);

[0019] A pump mode guiding structure (3-2-5) integrated in the cladding outside the gradual transition section (3-2-3) and the air-core stabilization section (3-2-4), and configured to realize spatial separation of the signal light and the pump light;

[0020] A hollow core output port (3-2-6) is used to connect the hollow core fiber (3-3) of the hollow core stable section (3-2-4).

[0021] In one embodiment, the cladding is uniformly provided with a plurality of independent air holes along the graded transition section (3-2-3) and the hollow core stable section (3-2-4), the air hole axis is parallel to the central axis of the hollow core solid hybrid combiner (3-2), one end of the air hole is in communication with the pump input fiber interface, and the other end extends to the cladding end outside the hollow core stable section (3-2-4), the inner wall of the air hole is coated with a film and the refractive index of the inner wall is higher than that of the cladding.

[0022] In one embodiment, the hollow core solid hybrid combiner (3-2) further comprises an isolation unit arranged between the input fiber port (3-2-1) and the solid lead-in section (3-2-2) for blocking reverse light.

[0023] In one embodiment, the hollow core fiber (3-3) comprises, from inside to outside, a hollow core transmission core (3-3-1), a gradient doped layer (3-3-2), and a filter cladding (3-3-3).

[0024] The hollow core transmission core (3-3-1) comprises an anti-resonant hollow core structure composed of a hollow channel and surrounding anti-resonant capillaries.

[0025] The gradient doped layer (3-3-2) is an annular quartz layer wrapped around the hollow core transmission core (3-3-1), and the doping concentration increases radially from inside to outside.

[0026] In one embodiment, the filter cladding (3-3-3) is an outer structure wrapped around the gradient doped layer (3-3-2) and is composed of a plurality of quartz capillaries arranged uniformly along the circumference, the capillaries are connected by fused quartz bridges to form a periodic photonic bandgap structure, the inner walls of the quartz capillaries are coated with multiple layers of alternating high and low refractive index films to form a distributed Bragg reflection structure, and the distributed Bragg reflection structure is used to reflect pump light satisfying total reflection conditions and transmit high-order mode pump light.

[0027] In one embodiment, a graded refractive index transition layer is arranged between the hollow core transmission core (3-3-1) and the gradient doped layer (3-3-2), and an isolation layer is arranged between the gradient doped layer (3-3-2) and the filter cladding (3-3-3).

[0028] In one embodiment, the pump guided mode structure (3-2-5) is used to realize spatial separation of signal light and pump light, the signal light is transmitted along the graded transition section (3-2-3) and the hollow core stable section (3-2-4), and the pump light is transmitted to the gradient doped layer (3-3-2) of the hollow core fiber (3-3) through the pump guided mode structure (3-2-5).

[0029] In one embodiment, the hollow transmission core (3-3-1) is divided from the inside out into a hollow channel (3-3-1-1), a quartz anti-resonant capillary (3-3-1-2), and a gradient refractive index transition layer (3-3-1-3).

[0030] The gradient doped layer (3-3-2) is divided into a doped layer (3-3-2-1) and an isolation layer (3-3-2-2) from the inside out.

[0031] The filter cladding (3-3-3) is divided into a distributed Bragg reflection structure (3-3-3-1) and a quartz sleeve (3-3-3-2) from the inside out.

[0032] In one embodiment, the optical antenna network (7) receives the echo signal reflected by the target object. The echo signal passes through the hollow fiber optic switch (4-2) in sequence, enters the hollow solid hybrid circulator (4-1) from the second port, and is output to the coherent detection module (5) from the third port.

[0033] In one embodiment, the optical antenna network (7) adjusts the number of optical antennas by modifying the parameters of the hollow fiber optical switch (4-2).

[0034] Beneficial effects:

[0035] In the aforementioned lidar networking system, the solid fiber amplifier of the pre-amplification module (2) first performs preliminary gain on the signal light, laying the foundation for subsequent amplification. The hybrid beam-combining main amplification module (3) efficiently couples the pump light and the pre-amplified signal through the hollow-core solid hybrid beam combiner (3-2), and achieves high-power amplification by combining with hollow fiber (3-3). This significantly reduces the nonlinear effect of traditional solid fiber under high power, and can maintain the high-quality characteristics of the signal light such as narrow linewidth and low distortion while increasing power, providing a high-fidelity signal source for subsequent detection.

[0036] Introducing hollow-core optical fiber as a signal transmission link in a lidar networking system fundamentally overcomes the technical limitations of traditional solid optical fiber, bringing multiple advantages to large-scale networking: Hollow-core optical fiber uses air or low-refractive-index gas as the transmission medium, and its nonlinear coefficient is lower than that of traditional solid optical fiber. m² / W, only for traditional solid optical fiber The signal attenuation in the air is approximately 1 / 2700th of that in solid fiber, and the transmission loss in the 1550nm band can be reduced to below 0.1dB / km, only half that of traditional solid fiber. This means that when high-power, narrow-linewidth signals output from hollow-core fiber amplifiers are transmitted through hollow-core fiber, they will not suffer from signal degradation due to nonlinear effects, nor will their power decrease significantly due to increased transmission distance. This ensures that remote nodes tens of kilometers away can still receive high-quality signals, significantly extending the network coverage from the traditional range of less than 5 kilometers to tens of kilometers, and enabling cross-regional networking without the need for additional repeater equipment.

[0037] Furthermore, the use of a single laser with a hollow-core optical switch and hollow-core fiber for long-distance transmission simplifies the network deployment process and reduces the total lifecycle cost. Eliminating the need for separate high-power lasers and amplifiers for each node significantly reduces the cost of the network system. Sharing the same laser also ensures high consistency in key parameters such as power and linewidth among the signals received by each node, avoiding signal discrepancies caused by multiple independent amplifiers. This improves the accuracy of multi-node data fusion and provides feasible technical support for large-scale, comprehensive monitoring in fields such as wind power, meteorology, and low-altitude economics. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of the architecture of a lidar networking system in one embodiment;

[0040] Figure 2 This is a schematic diagram of the hybrid beam combining main amplification module in one embodiment;

[0041] Figure 3 This is a schematic diagram of a transmit / receive module in one embodiment;

[0042] Figure 4 This is a schematic diagram of a hollow-solid hybrid bundle combiner in one embodiment;

[0043] Figure 5 This is a schematic diagram of the hollow fiber structure in one embodiment;

[0044] Figure 6 This is a schematic diagram of the hollow transmission core in one embodiment. Detailed Implementation

[0045] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0046] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0047] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0049] In one embodiment, Figure 1 This is a schematic diagram of the architecture of a lidar networking system in one embodiment.

[0050] The signal generation module (1) is used to output signal light and reference light. The signal light can be a polarization-maintaining narrow linewidth pulse light. The target distance is calculated by measuring the time difference from the pulse emission to the echo. The reference light can be a continuous local oscillator light. In the subsequent coherent detection module (5), the pulse light reflected by the target will be mixed with the local oscillator light. By calculating the frequency difference and phase difference between the two, the target's speed, distance and other information can be accurately extracted.

[0051] The pre-amplification module (2) is the pre-processing unit in the laser signal amplification link. It provides a qualified initial signal for the subsequent main amplification module (3). It uses a low-power solid fiber amplifier to perform preliminary gain on the narrow linewidth pulse light, increase the signal power to the range of the main amplification, and suppress noise.

[0052] Figure 2 This is a schematic diagram of a hybrid beam combining main amplification module in one embodiment. The hybrid beam combining main amplification module (3) consists of a pump laser (3-1), a hollow-solid hybrid beam combiner (3-2), and a hollow fiber (3-3). The pump laser (3-1) is used to output pump light. The number of pump lasers (3-1) can be adjusted according to the amplification requirements; there can be one or more. The pump light is equivalent to an energy source, used to provide the energy required for amplification of the signal light. The hollow-solid hybrid beam combiner (3-2) can achieve efficient coupling between the pump light and the pre-amplified signal light. Both are transmitted to the hollow fiber (3-3) along the same path, which reduces signal loss and allows the energy of the pump light to be uniformly transferred to the signal light, improving energy utilization efficiency. The structure of the hollow fiber (3-3) contains special materials that can absorb the energy of the pump light and then transfer it to the pre-amplified signal light, greatly increasing the power of the pre-amplified signal light. Moreover, the pre-amplified signal light is transmitted in the hollow channel and does not come into direct contact with the doped materials, avoiding the nonlinear effects of traditional solid fibers. After signal amplification, some residual pump light will remain, interfering with subsequent signal processing. Hollow-core fiber (3-3) can directly filter out this residual pump light without the need for additional filtering components, thus simplifying the structure.

[0053] Figure 3The following is a schematic diagram of the transmit and receive module in one embodiment. The transmit and receive module (4) realizes the transmission of high-power signals and the reception of low-power echo signals. It is mainly composed of a hollow-core solid hybrid circulator (4-1) and a hollow-core fiber optical switch (4-2). The first and second ports of the hollow-core solid hybrid circulator (4-1) are anti-resonant hollow fiber, and the third port is a standard single-mode polarization-maintaining solid fiber, which is connected to the coherent detection module (5). All the fibers of the hollow-core fiber optical switch (4-2) are anti-resonant hollow fiber with the same mode field as the first and second ports of the hollow-core solid hybrid circulator (4-1). A beam expansion component is designed at the output end of the anti-resonant hollow fiber to reduce the power density between the output end face of the hollow fiber and the incident surface of the remote optical antenna network (7) and avoid device damage. The secondary amplified signal light output from the hybrid beam-combining main amplification module (3) enters the hollow-core solid hybrid circulator (4-1) through the first port, and then is output to the hollow-core fiber optic switch (4-2) through the second port. It is then transmitted over a long distance to the remote optical antenna network (7) through the anti-resonant hollow fiber. The echo signal reflected from the target enters the remote optical antenna network (7) and the hollow-core fiber optic switch (4-2) in sequence, and then enters the hollow-core solid hybrid circulator (4-1) through the second port. The hollow-core solid hybrid circulator (4-1) performs signal separation, and outputs the echo signal from the standard single-mode polarization-maintaining solid fiber through the internally designed hollow-core-solid transition unit.

[0054] The coherent detection module (5) is used to receive the echo signal, mix the echo signal with the reference light, and convert it into an electrical signal;

[0055] The signal processing module (6) is used to process the electrical signal to obtain target information.

[0056] In the aforementioned lidar networking system, the solid fiber amplifier of the pre-amplification module (2) first performs preliminary gain on the signal light to lay the foundation for subsequent amplification. The hybrid beam-combining main amplification module (3) efficiently couples the pump light and the pre-amplified signal through the hollow-core solid hybrid beam combiner (3-2), and achieves high-power amplification by combining hollow fiber (3-3). This significantly reduces the nonlinear effects of traditional solid fiber under high power, and can maintain the high-quality characteristics of the signal light such as narrow linewidth and low distortion while increasing power, providing a high-fidelity signal source for subsequent detection.

[0057] In one embodiment, Figure 4 This is a schematic diagram of a hollow-solid hybrid bundler in one embodiment.

[0058] The input fiber optic port (3-2-1) contains two independent solid fiber optic interfaces for signal input and pump input. The signal input fiber is matched with the single-mode solid fiber output from the pre-amplification module (2). Depending on the amplification requirements, the pump input fiber can be one or multiple fibers. Figure 4The two pump input fiber ports are symmetrically distributed on both sides of the signal input fiber port, both of which are adapted to the solid fiber output from the main pump laser (3-1). The function of the input fiber port (3-2-1) is to achieve precise docking between the hollow-solid hybrid combiner (3-2) and external devices.

[0059] The solid guide section (3-2-2) is located near the signal input fiber port (3-2-1). The fiber core is a solid quartz structure, which enables lossless signal light input.

[0060] The material or structure of the gradient transition section (3-2-3) is gradually adjusted, eventually becoming a hollow channel, ensuring that the light energy enters the subsequent hollow channel as completely as possible. The gradient transition section (3-2-3) begins at the end of the solid introductory section (3-2-2), with the fiber core gradually transitioning from solid quartz to a hollow channel, while the mode field linearly expands from a single-mode mode field to a large mode field. The hollow stabilization section (3-2-4) is a stable large-mode-field hollow channel, maintaining the expanded large mode field while ensuring stable transmission of the laser mode to the output end. The gradient transition section (3-2-3) and the hollow stabilization section (3-2-4) together constitute the mode field transition region. Through the linear expansion of the mode field diameter, the energy of the input light gradually diffuses into the hollow mode field, greatly reducing coupling loss.

[0061] The pump guide structure (3-2-5) is integrated into the cladding of the mode field transition region, specifically in the cladding outside the gradient transition section (3-2-3) and the hollow stable section (3-2-4). This mode structure guides the pump light transmission, ensuring stable transmission along a predetermined path within the cladding and achieving spatial separation between the pre-amplified signal light and the pump light. The pre-amplified signal light enters from the solid inlet section (3-2-2), passes through the gradient transition section (3-2-3) to the hollow channel of the hollow stable section (3-2-4), and propagates along the center, maintaining a narrow linewidth. The pump light, after entering from the pump input, propagates within the pump guide structure (3-2-5), remaining entirely outside the pre-amplified signal light and spatially separated from it to avoid interference.

[0062] The hollow output port (3-2-6) is the connection interface between the hollow-solid hybrid combiner (3-2) and the hollow fiber (3-3). It enables low-loss connection with the hollow stable section (3-2-4) and precise docking with the hollow fiber (3-3).

[0063] In one embodiment, multiple independent vents in the cladding serve as transmission channels for the pump light. These vents are uniformly spaced along the cladding of the gradient transition section (3-2-3) and the hollow-core stable section (3-2-4), with the vent axis parallel to the central axis of the combiner. The vents are distributed around the periphery of the signal light channel, and their transmission direction is completely consistent with the signal light, ensuring that the pump light accompanies the signal light throughout its transmission for subsequent energy coupling. One end of each vent is connected to the pump input fiber interface, ensuring that the pump light enters the vent channel directly from the input port. The other end extends to the end of the cladding of the hollow-core stable section (3-2-4), ensuring that the pump light completely covers the transmission path of the signal light within the combiner, preventing interruptions. The inner wall of the vent is coated with a thin film, and the refractive index of the inner wall is higher than that of the cladding. When light travels from the inner wall of the vent to the cladding, total internal reflection occurs at the inner wall of the vent, preventing light leakage into the cladding and confining it within the vent for forward transmission, significantly reducing pump light loss.

[0064] In one embodiment, the hollow-solid hybrid combiner (3-2) further includes an isolation unit located between the input fiber port (3-2-1) and the solid guide section (3-2-2) to block reverse light.

[0065] In one embodiment, Figure 5 The diagram shows the structure of a hollow fiber in one embodiment, consisting of a hollow transmission core (3-3-1), a gradient doped layer (3-3-2), and a filter cladding (3-3-3) from the inside out.

[0066] The hollow transmission core (3-3-1) utilizes the geometry and refractive index distribution of the capillary to counteract reflection losses at the interface between the hollow channel and the capillary through anti-resonance, allowing the signal light to propagate primarily in the air. The core is filled with an inert gas. The mode field of the hollow transmission core (3-3-1) perfectly matches the mode field diameter of the output fiber of the hollow-solid hybrid combiner (3-2). The 1550nm signal light propagates with low loss in the hollow channel, while the anti-resonance structure allows only the fundamental mode to propagate stably, preventing mode instability.

[0067] After the pump light enters the hollow fiber (3-3) through the cladding pores of the hybrid combiner (3-2), it is mainly distributed in the outer region, exhibiting a gradient distribution with low concentration on the inner side and high concentration on the outer side. The doping concentration of the gradient doped layer (3-3-2) increases radially from the inside to the outside, allowing the high-concentration doped region on the outside to preferentially absorb more pump light energy and reduce energy waste. At the same time, the low concentration on the inner side avoids the increase in noise caused by the direct interaction between the signal light and the high-concentration dopant. The gradient doped layer (3-3-2) is a ring-shaped quartz layer surrounding the hollow transmission core (3-3-1), achieved through a doping process. Co-doping occurs when the doping concentration increases radially from the inside to the outside, creating an energy absorption gradient that is lower inside and higher outside. 980nm pump light injected from the pump mode structure (3-2-5) of the hollow-solid hybrid combiner (3-2) directly enters the gradient doped layer (3-3-2), providing energy for signal gain.

[0068] The filter cladding (3-3-3) is the outermost structure surrounding the gradient doped layer (3-3-2). The inner wall of the filter cladding (3-3-3) capillary is coated with multiple alternating high- and low-refractive-index films, forming a distributed Bragg reflection (DBR) structure. The DBR structure reflects pump light that satisfies the total internal reflection condition. This portion of the pump light is the useful pump light that is not completely absorbed by the gradient doped layer (3-3-2). After reflection, the DBR allows it to circulate within the cladding, where it is absorbed again by the gradient doped layer (3-3-2), improving pump light utilization. Higher-order mode pump light is transmitted, but its energy is dispersed, making it difficult to absorb effectively and potentially interfering with the signal light. The DBR allows it to be transmitted, preventing it from becoming noise. This distributed Bragg reflection structure is used to control the reflection or transmission characteristics of the 980nm pump light.

[0069] In one embodiment, a gradient refractive index transition layer is provided between the hollow transmission core (3-3-1) and the gradient doped layer (3-3-2). This transition layer, through a gradual change in refractive index, addresses the light reflection and mode field mismatch issues caused by the material differences between the two layers, thereby improving the energy interaction efficiency between the signal light and the gradient doped layer (3-3-2). An isolation layer is provided between the gradient doped layer (3-3-2) and the filter cladding layer (3-3-3). This isolation layer prevents unprocessed light from the gradient doped layer (3-3-2) from interfering with the filtering function of the filter cladding layer, and also prevents reflected light from the filter cladding layer from negatively impacting the energy absorption stability of the doped layer.

[0070] When the 1550nm signal light is transmitted with low loss as the fundamental mode in the hollow transmission core (3-3-1), some energy penetrates into the inner surface region of the gradient-doped layer (3-3-2) in the form of an evanescent wave, achieving non-contact amplification and avoiding nonlinear effects caused by direct contact between the signal light and the doped layer. The 980nm residual pump light that is not absorbed by the gradient-doped layer (3-3-2) diffuses outward and reaches the distributed Bragg reflection structure of the filter cladding (3-3-3), where total internal reflection occurs, and the residual pump light is reflected back to the gradient-doped layer (3-3-2) and absorbed again. The residual pump light that is not absorbed after reflection contains a large number of higher-order modes and its propagation direction is dispersed. When it reaches the interface of the filter cladding (3-3-3) for the second time, it cannot reach the condition of total internal reflection and the pump light is transmitted to the outer quartz sleeve and absorbed by the sleeve.

[0071] In one embodiment, Figure 6The diagram below illustrates the structure of the hollow transmission core in one embodiment. The hollow transmission core (3-3-1) consists of a hollow channel (3-3-1-1), a quartz anti-resonant capillary (3-3-1-2), and a gradient refractive index transition layer (3-3-1-3) from the inside out. The hollow channel (3-3-1-1) is the innermost hollow region and serves as the main transmission path for the signal light. It is filled with inert gas to reduce nonlinear effects at the source and maintain the narrow linewidth characteristics of the signal. The quartz anti-resonant capillary (3-3-1-2) is a ring-shaped capillary structure surrounding the hollow channel. It counteracts light reflection loss through the anti-resonance effect, ensuring that the signal light is transmitted stably only in the fundamental mode. The gradient refractive index transition layer (3-3-1-3) is the outermost transition structure. By gradually changing the refractive index, it reduces light reflection and improves energy interaction efficiency.

[0072] The gradient doped layer (3-3-2) consists of a doped layer (3-3-2-1) and a fluorine-doped isolation layer (3-3-2-2) from the inside out; the doped layer (3-3-2-1) is based on a quartz substrate. The co-doped layer, with doping concentration increasing from the inside to the outside, can efficiently absorb pump light energy and signal light from the hollow channel to achieve non-contact amplification. The isolation layer (3-3-2-2) is an outer isolation structure that prevents untreated light in the doped layer (3-3-2-1) from interfering with the screening function of the outer filter cladding, while also blocking reflected light from the filter cladding from affecting the stability of energy absorption.

[0073] The filter cladding (3-3-3) consists of a quartz capillary distributed Bragg reflection structure (3-3-3-1) and a quartz sleeve (3-3-3-2) from the inside out. The distributed Bragg reflection structure (3-3-3-1) is composed of a quartz capillary inner wall coated with alternating high and low refractive index films, which can reflect useful pump light that is not completely absorbed, while transmitting high-order mode pump light with dispersed energy that is prone to interfering with signals. The quartz sleeve (3-3-3-2) is the outermost protective structure, which absorbs the transmitted high-order mode pump light, completely removes stray light, and avoids interference with subsequent links.

[0074] In one embodiment, the core logic of the optical antenna network (7) is to decompose a large-scale detection target area into N sub-regions, with each remote optical antenna responsible for detecting one sub-region. By splicing together all the sub-regions, a large-scale area can be formed. The network can extend the detection boundary in terms of distance, range, dimension, and blind zone through the superposition of multiple antenna capabilities.

[0075] A single optical antenna has a limited detection range. Networking can extend the detection range by rationally configuring the positions of multiple optical antennas. For example, by networking an optical antenna with a radar with a detection range of 3km, and using 3 optical antennas placed in a straight line, a total detection range of 9km can be achieved.

[0076] Conventional radar uses multiple optical antennas concentrated in one location to achieve small-area measurements. A network system can distribute these multiple optical antennas to achieve large-area measurements. For example, a single optical antenna can achieve a detection range with a diameter of 30 meters. By rationally configuring multiple optical antennas, each covering a portion of the area, and with the edges of these areas connecting, a detection range with a diameter exceeding 100 meters can be achieved.

[0077] A single optical antenna can typically only achieve detection at a fixed elevation angle. Networking can cover all dimensions by using multiple optical antennas with complementary angles. For example, by networking an optical antenna with a fixed elevation angle of 60° and using three optical antennas with reasonable angle configuration, it is possible to achieve detection within a 180° angle range. Multiple optical antennas, through reasonable configuration, can not only compensate for the blind spots of a single radar but also compensate for blind spots caused by obstructions.

[0078] Furthermore, the number of network antennas can be flexibly configured. For example, a 1x8 optical switch can support a network of up to 8 optical antennas. If only 5 optical antennas are needed, the optical switch parameters can be modified so that only 5 channels operate normally, saving energy and preventing damage from the lasers on the other 3 channels. If a network of 10 optical antennas is temporarily required, a 1x3 optical switch can be cascaded on one of the optical paths of the 1x8 optical switch to achieve temporary capacity expansion. Using hollow-core optical switches in conjunction with hollow-core optical fibers for long-distance transmission also simplifies the network deployment process and reduces the total lifecycle cost.

[0079] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0080] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A laser radar networking system, characterized by, The system comprises a laser and an optical antenna network (7), the laser is sequentially connected by a signal generation module (1), a pre-amplification module (2), a hybrid beam main amplification module (3), a transmitting and receiving module (4), a coherent detection module (5), a signal processing module (6), and the optical antenna network (7) comprises a plurality of optical antennas; The signal generation module (1) is used for outputting signal light and reference light; The pre-amplification module (2) comprises a solid core fiber amplifier, which is used for amplifying the signal light to obtain pre-amplified signal light; The hybrid beam main amplification module (3) comprises a pump laser (3-1), a hollow core solid hybrid beam combiner (3-2) and a hollow core fiber (3-3), the pump laser (3-1) is used for outputting pump light, the hollow core solid hybrid beam combiner (3-2) is used for coupling the pre-amplified signal light and the pump light, and the hollow core fiber (3-3) is used for amplifying the pre-amplified signal light to obtain twice-amplified signal light; The transmitting and receiving module (4) comprises a hollow core solid hybrid circulator (4-1) and a hollow core fiber optical switch (4-2), the hollow core solid hybrid circulator (4-1) comprises a first port, a second port and a third port, the first port is used for receiving the twice-amplified signal light and transmitting the twice-amplified signal light to the hollow core fiber optical switch (4-2) through the second port, the hollow core fiber optical switch (4-2) is connected with the optical antenna network (7), and the third port is connected with the coherent detection module (5); The coherent detection module (5) is used for receiving echo signals, mixing the echo signals with the reference light and converting the echo signals into electrical signals; The signal processing module (6) is used for processing the electrical signals to obtain target object information.

2. The system of claim 1, wherein, The hollow core solid hybrid beam combiner (3-2) comprises: An input fiber port (3-2-1) comprising a signal input fiber interface and a pump input fiber interface; A solid core lead-in section (3-2-2) connected with the signal input fiber interface, wherein a fiber core of the solid core lead-in section (3-2-2) is in a solid structure; A gradual transition section (3-2-3) connected with the solid core lead-in section (3-2-2), wherein a fiber core of the gradual transition section (3-2-3) gradually transitions from a solid structure to a hollow structure, and a mode field linearly expands from a single mode field to a large mode field; A hollow core stabilization section (3-2-4) connected with the gradual transition section (3-2-3); A pump mode guiding structure (3-2-5) integrated in a cladding outside the gradual transition section (3-2-3) and the hollow core stabilization section (3-2-4), which is used for realizing spatial separation of the signal light and the pump light; A hollow core output port (3-2-6) used for connecting the hollow core stabilization section (3-2-4) and the hollow core fiber (3-3).

3. The system of claim 2, wherein, The cladding uniformly has a plurality of independent air holes along the gradual transition section (3-2-3) and the hollow core stabilization section (3-2-4), an air hole axis is parallel to a central axis of the hollow core solid hybrid beam combiner (3-2), one end of the air hole is in communication with the pump input fiber interface, the other end of the air hole extends to a cladding end outside the hollow core stabilization section (3-2-4), an inner wall of the air hole is coated with a film, and a refractive index of the inner wall is higher than a refractive index of the cladding.

4. The system of claim 2, wherein, The hollow-core solid hybrid beam combiner (3-2) further comprises an isolation unit arranged between the input fiber port (3-2-1) and the solid lead-in section (3-2-2) for blocking the reverse light.

5. The system of claim 1, wherein, The hollow-core fiber (3-3) comprises, from inside to outside, a hollow transmission core (3-3-1), a gradient-doped layer (3-3-2), and a filter cladding (3-3-3). The hollow transmission core (3-3-1) comprises an anti-resonant hollow channel and surrounding anti-resonant capillaries. The gradient-doped layer (3-3-2) is an annular quartz layer wrapped around the hollow transmission core (3-3-1), and the doping concentration increases gradually from inside to outside along the radial direction. The filter cladding (3-3-3) is an outer structure wrapped around the gradient-doped layer (3-3-2) and comprises a plurality of quartz capillaries arranged uniformly along the circumference, and the capillaries are connected by fused quartz bridges to form a periodic photonic bandgap structure. The inner wall of the quartz capillary is coated with a plurality of alternating high-refractive-index and low-refractive-index thin films to form a distributed Bragg reflection structure. The distributed Bragg reflection structure is used for reflecting pump light satisfying total reflection conditions and transmitting high-order mode pump light.

6. The system of claim 5, wherein, A gradient-index transition layer is arranged between the hollow transmission core (3-3-1) and the gradient-doped layer (3-3-2), and an isolation layer is arranged between the gradient-doped layer (3-3-2) and the filter cladding (3-3-3).

7. The system of claim 2, wherein, The pump guiding structure (3-2-5) is used for spatial separation of signal light and pump light. The signal light is transmitted along the gradient transition section (3-2-3) and the hollow-core stable section (3-2-4), and the pump light is transmitted to the gradient-doped layer (3-3-2) of the hollow-core fiber (3-3) through the pump guiding structure (3-2-5).

8. The system of claim 5, wherein, The hollow transmission core (3-3-1) comprises, from inside to outside, a hollow channel (3-3-1-1), a quartz anti-resonant capillary (3-3-1-2), and a gradient-index transition layer (3-3-1-3). The gradient-doped layer (3-3-2) comprises, from inside to outside, a doped layer (3-3-2-1) and an isolation layer (3-3-2-2). The filter cladding (3-3-3) comprises, from inside to outside, a distributed Bragg reflection structure (3-3-3-1) and a quartz sleeve (3-3-3-2).

9. The system of claim 1, wherein, The optical antenna network (7) is used for receiving echo signals reflected by a target object. The echo signals enter the hollow-core solid hybrid circulator (4-1) from the second port through the hollow-core fiber optical switch (4-2) and are output from the third port to the coherent detection module (5).

10. The system of claim 1, wherein, The optical antenna network (7) adjusts the number of optical antennas by modifying the parameters of the hollow-core fiber optical switch (4-2).

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