Incoherent light long-distance three-dimensional imaging device using multi-beam synthesis
By using an incoherent optical imaging device with multi-beam synthesis and atmospheric random modulation, the problem of long-distance high resolution in optical three-dimensional imaging under atmospheric turbulence was solved. It achieved high collimation and high-intensity thermal light source synthesis, thereby improving imaging resolution and ranging accuracy.
Patent Information
- Application Number
- CN202511304645.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-12
- Publication Date
- 2025-11-25
AI Technical Summary
Existing optical 3D imaging technologies cannot overcome atmospheric turbulence to achieve high-resolution imaging over long distances. In particular, the small lateral coherence size of thermal light sources leads to the reception of photons in the incoherent part, resulting in a decrease in second-order coherence, a long distance accumulation time, and difficulty in actively detecting and tracking targets.
A non-coherent light long-distance three-dimensional imaging device employing multi-beam synthesis achieves multi-beam synthesis and atmospheric random modulation through a multi-fiber beam splitter, a multi-channel modulator, a transmitting and receiving collimating lens group, a filter, a single-photon detector, and a time correlation module. Combined with active and passive amplitude and phase modulation, it utilizes intensity correlation to achieve super-resolution imaging and ranging.
It achieves the synthesis of high-collimation, high-intensity, narrow-band thermal light sources, overcomes the influence of atmospheric turbulence, and improves the resolution and ranging accuracy of long-distance 3D imaging, making it suitable for long-distance high-resolution 3D imaging.
Smart Images
Figure CN121008291A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of incoherent light correlation imaging technology, and more specifically to a long-distance three-dimensional imaging device using incoherent light synthesized from multiple beams. Background Technology
[0002] Optical 3D imaging typically employs coherent laser active emission, combining time-of-flight measurement of target distance with 2D passive imaging to form a 3D image. However, the emitted laser is affected by environmental factors such as the atmosphere, causing rapid phase changes and intensity decay. The ranging distance is limited by the emission intensity, and the 2D image can be blurred by turbulence, with imaging resolution limited by the receiver aperture.
[0003] Intensity correlation imaging based on thermal-optical second-order coherence can overcome atmospheric turbulence and optical aperture limitations to achieve super-resolution two-dimensional imaging. Many research groups both domestically and internationally have conducted studies on the second-order coherence of thermal light sources and ghost imaging experiments. Thermal light sources typically possess characteristics such as broad spectrum and large divergence angles. To meet the requirement that the system's temporal resolution is smaller than the light source's coherence time, narrowband filtering is necessary, leading to a reduction in the average photon number for each frequency mode and spatial mode, hindering its application in long-distance imaging and ranging. On the other hand, research on ranging using thermal light sources is scarce, mainly because the lateral coherence dimension of thermal light sources is small, resulting in the reception of incoherent photons and a significant decrease in measured second-order coherence. This leads to a long ranging accumulation time, making it difficult to actively detect and continuously track targets, thus obscuring its application prospects.
[0004] In summary, there is an urgent need to develop high-collimation, high-intensity, narrow-band thermal light source imaging and ranging technologies to provide technical support for the engineering application of long-range high-resolution three-dimensional imaging technology that is resistant to atmospheric turbulence. Summary of the Invention
[0005] To address the shortcomings of existing technologies, this invention provides a long-distance three-dimensional imaging device using incoherent light synthesized from multiple beams, which solves the problem that optical three-dimensional imaging cannot overcome atmospheric turbulence to achieve high-resolution imaging at long distances.
[0006] To achieve the above objectives, the present invention provides the following technical solution:
[0007] A long-distance three-dimensional imaging device using incoherent light synthesized by multi-beam synthesis, the three-dimensional imaging device comprising: a laser, a multi-fiber beam splitter, a multi-channel modulator, a transmitting collimating lens group, a receiving collimating lens group, a filter, a single-photon detector, a time correlation module, and a three-dimensional imaging reconstruction processing module;
[0008] The transmitting collimating lens group includes 2N transmitting collimating lenses, and the receiving collimating lens group includes N receiving collimating lenses, where N is an integer and N≥2;
[0009] The laser is connected to the multi-fiber beam splitter, the multi-fiber beam splitter to the multi-channel modulator, and the multi-channel modulator to each transmitting collimator via multimode fiber.
[0010] The receiving collimating lens and the corresponding filter, as well as the filter and the corresponding single-photon detector, are all connected by single-mode optical fiber.
[0011] The laser is connected to the time correlation module, and the time correlation module is connected to each single-photon detector via radio frequency cables; the time correlation module is connected to the 3D imaging reconstruction processing module via a network cable.
[0012] The laser generates pulsed light signals; the fiber optic beam splitter divides the laser into 2N paths; the multi-channel modulator performs random amplitude and phase modulation on the 2N input beams; the modulated 2N beams are emitted in parallel through 2N spatially separated transmitting collimators and converged to the target; incoherent light synthesis with random amplitude and phase over long distances is achieved using multi-channel modulation and atmospheric random modulation; the receiving collimators are combined to form an aperture to receive the incoherent light reflected from the target; and a filter and a single-photon detector are used to select a narrowband spectrum for coincidence measurement, achieving super-resolution imaging based on intensity correlation, with an imaging resolution δ = 1.22λL / B.
[0013] Where λ is the laser wavelength;
[0014] L is the target distance;
[0015] B is the synthetic aperture length;
[0016] By utilizing the pulse flight time of actively emitted lasers for ranging, three-dimensional reconstruction imaging of distant targets can be achieved.
[0017] Preferably, the multi-channel modulator can actively apply different random amplitude and phase modulations to multiple lasers at different times.
[0018] Preferably, the spacing between adjacent transmitting collimators is greater than the atmospheric coherence length of 0.05m, so that each transmission at the long-distance synthesis point obtains a different atmospheric modulation phase as passive random modulation.
[0019] Preferably, the emitting collimating mirrors in the emitting collimating mirror group all emit parallel light and can independently adjust the emission orientation to achieve light field convergence and superposition at any distance.
[0020] Preferably, the receiving collimating mirror is mounted on a two-dimensional displacement stage, and the distance between adjacent receiving collimating mirrors remains fixed during the measurement process, enabling the scanning and reception of incoherent echoes scattered by targets at different positions in a two-dimensional plane.
[0021] Preferably, the filter is a tunable Bragg fiber grating filter or a tunable Fabry-Perot filter, and the center wavelengths of all filters are kept coincident through tuning and temperature control.
[0022] Preferably, the single-photon detector is a Geiger-mode avalanche diode or an enhancement-mode charge-coupled device that converts optical signals into electrical signals. All single-photon detectors have similar or identical quantum efficiencies and dark noise levels.
[0023] Preferably, the time correlation module processes N+1 signals simultaneously, and the laser-emitted pulse signal is connected to the trigger channel of the time correlation module; the outputs of the N single-photon detectors are respectively connected to the N detection channels of the time correlation module.
[0024] Preferably, the receiving collimating lens group includes: a first receiving collimating lens and a second receiving collimating lens; N=2;
[0025] The first receiving collimating lens is matched with a corresponding first filter and a first single-photon detector;
[0026] The second receiving collimating lens is matched with a corresponding second filter and a second single-photon detector;
[0027] The time correlation module processes three signals simultaneously. The laser-emitted pulse signal is connected to the trigger channel of the time correlation module; the outputs of the first single-photon detector and the second single-photon detector are respectively connected to the first detection channel and the second detection channel of the time correlation module.
[0028] Preferably, the imaging method of the three-dimensional imaging device includes:
[0029] Set the laser emission pulse parameters of the laser, emit pulses of a specific period, and generate a pulse timing access to the trigger channel of the time-related module;
[0030] Periodic pulses are split into multiple paths by a multi-path fiber optic beam splitter;
[0031] The multi-beam beams are superimposed by a multi-channel modulator with random amplitudes and phases that change over time, and are then emitted through the emitting collimating lens group respectively.
[0032] Adjust the distance between the transmitting collimating mirrors to be greater than the atmospheric coherence wavelength, and adjust the angle of the transmitting collimating mirrors to converge to the approximate distance of the target to be measured;
[0033] Two-dimensional scanning receives collimating lens group to obtain the echo photons of the target under test, and selects the same narrow spectral band for detection through filter;
[0034] All single-photon detectors convert the filtered optical signal into an electrical signal, which is then connected to all detection channels of the time-correlation module.
[0035] Using the trigger channel electrical signal as the start signal and the second single-photon detector electrical signal as the stop signal, the flight time t of the echo photons at different positions of the target under test is obtained according to the scanning azimuth of the first receiving collimating lens. i The target distance d is obtained. i =ct i / 2, where c is the speed of light;
[0036] Using the electrical signal of the first detection channel as the start signal and the electrical signal of the second detection channel as the end signal, a two-dimensional image of the echo intensity distribution at different positions of the target under test is obtained according to the scanning orientation of the receiving collimating lens group.
[0037] A 3D image is obtained by fusing azimuth, pitch, and distance information through a 3D imaging reconstruction algorithm.
[0038] This invention provides a long-range three-dimensional imaging device utilizing incoherent light synthesized from multiple beams. Compared with existing technologies, it has the following advantages:
[0039] In this invention, the three-dimensional imaging device employs multi-beam transmission and optical synthetic aperture reception. The number of transmitted beams can be increased to improve transmission power according to the application scenario, making it suitable for long-distance imaging. The increased baseline of the receiving aperture can further improve imaging resolution. Furthermore, it can utilize multi-channel modulation and atmospheric random modulation to achieve incoherent light synthesis with random amplitude and phase over long distances. This combination of active and passive amplitude and phase random modulation synthesizes a high-collimation, high-intensity, narrow-band thermal light source, compensating for the inherent periodicity of active modulation and the disadvantage of short coherence time caused by slow atmospheric modulation speed. Through the second-order coherence of this light source, high-resolution three-dimensional imaging of distant targets with turbulence resistance can be achieved. Attached Figure Description
[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0041] Figure 1 This is a schematic diagram of the structure of the three-dimensional imaging device in an embodiment of the present invention. Detailed Implementation
[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0043] This application provides a long-distance three-dimensional imaging device using incoherent light synthesized by multiple beams, which solves the problem that optical three-dimensional imaging cannot overcome atmospheric turbulence to achieve high-resolution imaging at long distances.
[0044] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.
[0045] Example 1:
[0046] like Figure 1 As shown, the present invention provides a long-distance three-dimensional imaging device using incoherent light synthesized by multi-beam synthesis. The three-dimensional imaging device includes: a laser, a multi-fiber beam splitter, a multi-channel modulator, a transmitting collimating lens group, a receiving collimating lens group, a filter, a single-photon detector, a time correlation module, and a three-dimensional imaging reconstruction processing module.
[0047] The transmitting collimating lens group includes 2N transmitting collimating lenses, and the receiving collimating lens group includes N receiving collimating lenses, where N is an integer and N≥2;
[0048] The laser is connected to the multi-fiber beam splitter, the multi-fiber beam splitter to the multi-channel modulator, and the multi-channel modulator to each transmitting collimator via multimode fiber.
[0049] The receiving collimating lens and the corresponding filter, as well as the filter and the corresponding single-photon detector, are all connected by single-mode optical fiber.
[0050] The laser and the time correlation module, as well as the time correlation module and each single-photon detector, are connected via radio frequency cables; the time correlation module and the three-dimensional imaging reconstruction processing module are connected via network cables.
[0051] The laser generates pulsed light signals; the fiber optic beam splitter divides the laser into 2N paths; a multi-channel modulator randomly modulates the amplitude and phase of the 2N input lights; the modulated 2N lights are emitted in parallel through 2N spatially separated transmitting collimators and converged to the target. Long-distance incoherent light synthesis with random amplitude and phase is achieved using multi-channel modulation and atmospheric random modulation; receiving collimators are combined to form an aperture to receive the incoherent light reflected from the target; the light reflected from the target received by the receiving collimators is filtered by corresponding filters to select narrowband spectra in the same wavelength band for measurement, and then converted into electrical signals by corresponding single-photon detectors; the receiving collimators are scanned, and intensity correlation is performed on all single-photon detectors through a time correlation module to achieve two-dimensional super-resolution imaging of the target; the laser pulse timing is correlated with one of the single-photon detectors through the time correlation module, and accurate target ranging is performed based on the pulse flight time of the actively emitted laser; the three-dimensional imaging reconstruction processing module integrates the two-dimensional super-resolution imaging, ranging information, and the angle of the receiving collimators to reconstruct a three-dimensional image of the object.
[0052] The multi-channel modulator can actively apply different random amplitude and phase modulations to multiple lasers at different times. On the other hand, the adjacent spacing of the transmitting collimator is greater than the atmospheric coherence length of 0.05m, so that each emission at the long-distance synthesis point obtains a different atmospheric modulation phase as passive random modulation. The transmitting collimators in the transmitting collimator group all emit parallel light and can independently adjust the emission orientation to achieve light field convergence and superposition at any distance. In summary, the synthesis of thermal light source combining active and passive modulation is realized.
[0053] This combination of active and passive amplitude and phase random modulation compensates for the inherent periodicity of active modulation and the disadvantage of short coherence time caused by slow atmospheric modulation speed; it realizes an actively controllable small divergence angle, high power, narrowband incoherent light source, which is suitable for long-distance high-resolution imaging.
[0054] The receiving collimating mirror is mounted on a two-dimensional displacement stage. The distance between adjacent receiving collimating mirrors is adjustable. During the measurement process, the distance between adjacent receiving collimating mirrors remains fixed, enabling the scanning and reception of incoherent echoes scattered by the target at different positions in a two-dimensional plane.
[0055] The receiving collimating lens and the two-dimensional displacement stage can be connected in various conventional ways to achieve the above functions. The following is an example to illustrate this; other connection methods will not be elaborated on:
[0056] The receiving collimator is equipped with a slider, and the two-dimensional displacement stage is equipped with a slide rail. The slider and the slide rail are slidably connected. The slider has a threaded hole, and the threaded hole is connected to a clamping bolt. When the clamping bolt is tightened, the head of the clamping bolt abuts against the slide rail, thereby fixing the receiving collimator and the two-dimensional displacement stage relatively. When the clamping bolt is loosened, the head of the clamping bolt moves away from the slide rail, and the two no longer contact each other. At this time, the receiving collimator can slide freely along the slide rail, thereby adjusting the distance between adjacent receiving collimators.
[0057] The filters are of the types such as tunable Bragg fiber grating filters and tunable Fabry-Perot filters. The center wavelengths of all filters are kept to coincide through tuning and temperature control. Narrowband spectra below about 4 pm are selected for coincidence measurement.
[0058] The single-photon detector is a Geiger-mode avalanche diode or an enhanced charge-coupled device that converts optical signals into electrical signals. All single-photon detectors have similar or identical quantum efficiencies and dark noise levels, approximately 10%@1000cps, and time jitter of less than 400ps, ensuring that intensity fluctuation correlations are not overwhelmed by additional noise. Based on the laser pulse time-of-flight ranging principle, the target distance is obtained.
[0059] Super-resolution imaging is achieved based on the intensity correlation of the thermo-optical field. According to the Rayleigh diffraction limit formula, the theoretical resolution of this invention is δ=1.22λL / B.
[0060] Where λ is the laser wavelength;
[0061] L is the target distance;
[0062] B represents the synthetic aperture length.
[0063] The time correlation module processes N+1 signals simultaneously, with an optimal time resolution of less than 10 ps; the laser emits pulse signals and connects them to the trigger channel of the time correlation module; the outputs of the N single-photon detectors are respectively connected to the N detection channels of the time correlation module.
[0064] The 3D imaging reconstruction processing module uses deep learning and strategy optimization algorithms to quickly reconstruct the 3D image of the object from information such as super-resolution imaging, ranging information, and the angle of the receiving collimator, thus completing the 3D reconstruction imaging of the target object.
[0065] The three-dimensional imaging device employs multi-beam transmission and optical synthetic aperture reception. The number of transmitted beams can be increased to improve transmission power according to the application scenario, making it suitable for long-distance imaging. The increased baseline of the receiving aperture can further improve the imaging resolution. Furthermore, it can utilize the random phase applied by atmospheric disturbances to synthesize a high-collimation, high-intensity, narrow-band thermal light source through a combination of active and passive modulation. The second-order coherence of this light source enables high-resolution three-dimensional imaging of distant targets against turbulence.
[0066] Example 2:
[0067] The receiving collimating lens group includes: a first receiving collimating lens and a second receiving collimating lens; N=2;
[0068] The first receiving collimating lens is matched with a corresponding first filter and a first single-photon detector;
[0069] The second receiving collimating lens is matched with a corresponding second filter and a second single-photon detector.
[0070] The time correlation module processes three signals simultaneously. The laser-emitted pulse signal is connected to the trigger channel of the time correlation module; the outputs of the first single-photon detector and the second single-photon detector are respectively connected to the first detection channel and the second detection channel of the time correlation module.
[0071] Using the trigger channel as the start signal and the second single-photon detector's electrical signal as the stop signal, the flight time t of the echo photons at different positions of the target under test is obtained based on the scanning azimuth of the first receiving collimating lens. i Target distance d i =ct i / 2, where c is the speed of light;
[0072] Using the electrical signal of the first detection channel as the start signal and the electrical signal of the second detection channel as the end signal, a two-dimensional image of the echo intensity distribution at different positions of the target under test is obtained based on the scanning azimuth of the first and second receiving collimating lenses. Through deep learning and policy optimization, the azimuth, elevation, and range information are fused to reconstruct a three-dimensional image of the distant target.
[0073] In summary, compared with the prior art, the present invention has the following beneficial effects:
[0074] In this embodiment of the invention, the three-dimensional imaging device employs multi-beam transmission and optical synthetic aperture reception. The number of transmitted beams can be increased to improve transmission power according to the application scenario, making it suitable for long-distance imaging. The increased baseline of the receiving aperture can further improve the imaging resolution. Furthermore, it can utilize multi-channel modulation and atmospheric random modulation to achieve incoherent light synthesis with random amplitude and phase over long distances. This combination of active and passive amplitude and phase random modulation synthesizes a high-collimation, high-intensity, narrow-band thermal light source, compensating for the inherent periodicity of active modulation and the disadvantage of short coherence time caused by slow atmospheric modulation speed. Through the second-order coherence of this light source, high-resolution three-dimensional imaging of distant targets with anti-turbulence can be achieved.
[0075] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0076] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A long-distance three-dimensional imaging device utilizing incoherent light synthesized from multiple beams, characterized in that, The three-dimensional imaging device includes: a laser, a multi-fiber beam splitter, a multi-channel modulator, a transmitting collimating lens group, a receiving collimating lens group, a filter, a single-photon detector, a time correlation module, and a three-dimensional imaging reconstruction processing module; The transmitting collimating lens group includes 2N transmitting collimating lenses, and the receiving collimating lens group includes N receiving collimating lenses, where N is an integer and N≥2; The laser is connected to the multi-fiber beam splitter, the multi-fiber beam splitter to the multi-channel modulator, and the multi-channel modulator to each transmitting collimator via multimode fiber. The receiving collimating lens and the corresponding filter, as well as the filter and the corresponding single-photon detector, are all connected by single-mode optical fiber. The laser is connected to the time correlation module, and the time correlation module is connected to each single-photon detector via radio frequency cables; the time correlation module is connected to the 3D imaging reconstruction processing module via a network cable. The laser generates pulsed light signals; the fiber optic beam splitter divides the laser into 2N paths; the multi-channel modulator performs random amplitude and phase modulation on the 2N input beams; the modulated 2N beams are emitted in parallel through 2N spatially separated transmitting collimators and converged to the target; incoherent light synthesis with random amplitude and phase over long distances is achieved using multi-channel modulation and atmospheric random modulation; the receiving collimators are combined to form an aperture to receive the incoherent light reflected from the target; and a filter and a single-photon detector are used to select a narrowband spectrum for coincidence measurement, achieving super-resolution imaging based on intensity correlation, with an imaging resolution δ = 1.22λL / B. Where λ is the laser wavelength; L is the target distance; B is the synthetic aperture length; By utilizing the pulse flight time of actively emitted lasers for ranging, three-dimensional reconstruction imaging of distant targets can be achieved.
2. The long-distance three-dimensional imaging device using incoherent light synthesized by multi-beam synthesis as described in claim 1, characterized in that, The multi-channel modulator can actively apply different random amplitude and phase modulations to multiple lasers at different times.
3. The long-distance three-dimensional imaging device using incoherent light synthesized by multi-beam synthesis as described in claim 1, characterized in that, The spacing between adjacent transmitting collimators is greater than the atmospheric coherence length of 0.05m, so that each transmission at the long-distance synthesis point obtains a different atmospheric modulation phase as passive random modulation.
4. The long-distance three-dimensional imaging device using incoherent light synthesized by multi-beam synthesis as described in claim 1, characterized in that, The transmitting collimating mirrors in the transmitting collimating mirror group all emit parallel light and can independently adjust the emission orientation to achieve light field convergence and superposition at any distance.
5. The long-distance three-dimensional imaging device using incoherent light synthesized by multi-beam synthesis as described in claim 1, characterized in that, The receiving collimating mirror is mounted on a two-dimensional displacement stage. During the measurement process, the distance between adjacent receiving collimating mirrors remains fixed, enabling the scanning and reception of incoherent echoes scattered by targets at different positions in a two-dimensional plane.
6. The long-distance three-dimensional imaging device using incoherent light synthesized by multi-beam synthesis as described in claim 1, characterized in that, The filters are either tunable Bragg fiber grating filters or tunable Fabry-Perot filters, and the center wavelengths of all filters are kept to coincide through tuning and temperature control.
7. The long-distance three-dimensional imaging device using incoherent light synthesized by multi-beam synthesis as described in claim 1, characterized in that, The single-photon detector is a Geiger-mode avalanche diode or an enhanced charge-coupled device that converts optical signals into electrical signals. All single-photon detectors have similar or identical quantum efficiencies and dark noise levels.
8. The long-distance three-dimensional imaging device using incoherent light synthesized by multi-beam synthesis as described in claim 1, characterized in that, The time correlation module processes N+1 signals simultaneously. The laser emits a pulse signal which is connected to the trigger channel of the time correlation module. The outputs of the N single-photon detectors are respectively connected to the N detection channels of the time correlation module.
9. The long-distance three-dimensional imaging device using incoherent light synthesized by multi-beam synthesis as described in claim 8, characterized in that, The receiving collimating lens group includes: a first receiving collimating lens and a second receiving collimating lens; N=2; The first receiving collimating lens is matched with a corresponding first filter and a first single-photon detector; The second receiving collimating lens is matched with a corresponding second filter and a second single-photon detector; The time correlation module processes three signals simultaneously. The laser-emitted pulse signal is connected to the trigger channel of the time correlation module; the outputs of the first single-photon detector and the second single-photon detector are respectively connected to the first detection channel and the second detection channel of the time correlation module.
10. The long-distance three-dimensional imaging device using incoherent light synthesized by multi-beam synthesis as described in claim 1, characterized in that, The imaging method of the three-dimensional imaging device includes: Set the laser emission pulse parameters of the laser, emit pulses of a specific period, and generate a pulse timing access to the trigger channel of the time-related module; Periodic pulses are split into multiple paths by a multi-path fiber optic beam splitter; The multi-beam beams are superimposed by a multi-channel modulator with random amplitudes and phases that change over time, and are then emitted through the emitting collimating lens group respectively. Adjust the distance between the transmitting collimating mirrors to be greater than the atmospheric coherence wavelength, and adjust the angle of the transmitting collimating mirrors to converge to the approximate distance of the target to be measured; Two-dimensional scanning receives collimating lens group to obtain the echo photons of the target under test, and selects the same narrow spectral band for detection through filter; All single-photon detectors convert the filtered optical signal into an electrical signal, which is then connected to all detection channels of the time-correlation module. Using the trigger channel electrical signal as the start signal and the second single-photon detector electrical signal as the stop signal, the flight time t of the echo photons at different positions of the target under test is obtained according to the scanning azimuth of the first receiving collimating lens. i The target distance d is obtained. i =ct i / 2, where c is the speed of light; Using the electrical signal of the first detection channel as the start signal and the electrical signal of the second detection channel as the end signal, a two-dimensional image of the echo intensity distribution at different positions of the target under test is obtained according to the scanning orientation of the receiving collimating lens group. A 3D image is obtained by fusing azimuth, pitch, and distance information through a 3D imaging reconstruction algorithm.