A multi-aperture coherent synthetic split-phase modulation detection system

Abstract

This invention provides a multi-aperture coherent combining system with split-path phase modulation detection, relating to the field of optoelectronic technology. The system, along the optical path, sequentially includes a split-beam laser source module, a signal generation module, a multi-aperture emission module, a signal demodulation module, and a marker feedback module. The signal generation module receives multiple split-beam lasers and generates different modulation signals, using these signals to modulate different split-beam lasers. The signal demodulation module, located at the optical axis of a far-field target, demodulates the modulated split-beam lasers in the combined beam to obtain split-beam lasers deviating from the optical axis. The marker feedback module marks the deviated split-beam lasers and feeds them back to the optical axis processing module connected to the split-beam laser source module, thereby enabling the detection of far-field spots. This invention solves the problems of low compensation accuracy and efficiency in closed-loop correction during multi-aperture coherent combining.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic technology, and in particular to a multi-aperture coherent synthesis split-path phase modulation detection system. Background Technology

[0002] Coherent combining is a technique that increases the amplitude of a laser array by combining the phase, polarization, and optical path of multiple unit lasers. This not only increases the power density at the target location to N times the power density of a single unit laser, but also... 2 It can achieve multiple times (N is the number of synthesis units) and continuously improve the synthesis power while maintaining the quality of the laser synthesis beam.

[0003] Currently, multi-aperture coherent combining has become the main method for generating high-power beams. That is, firstly, a seed laser is amplified in power by a fiber laser preamplifier; then, the amplified laser is split into multiple beams by a laser beam splitter; next, each beam passes through the same phase modulator, amplifier, collimator, and other units before being output; finally, all the output beams are combined by a laser beam combiner to form an array laser before being emitted. To ensure improved energy focusing of the combined beam, existing multi-aperture coherent combining methods utilize the image of the far-field spot to form a feedback loop for laser correction, ensuring that each laser beam has the same phase, optical path length, power, polarization, beam diameter, and spatial orientation during the multi-aperture coherent combining process.

[0004] However, due to the large number of synthesis units and the long transmission distance, the far-field beams of multi-aperture coherent synthesis methods such as SPGD (stochastic parallel gradient descent), multi-jitter phase-locked loop, genetic algorithm, and deep learning neural network are all randomly adjusted, which cannot accurately identify the angle and position deviation of the emitted beam and cannot perform accurate compensation. In addition, the large number of synthesis units makes the convergence iteration of multi-aperture coherent synthesis methods slow and the algorithm time long, resulting in low compensation efficiency. Summary of the Invention

[0005] Therefore, it is necessary to provide a multi-aperture coherent synthesis split-path phase modulation detection system to address the above-mentioned technical problems and solve the problems of low compensation accuracy and efficiency in closed-loop correction during multi-aperture coherent synthesis.

[0006] This invention provides a multi-aperture coherent combining split-path phase modulation detection system, the system comprising, along the optical path direction, the following components in sequence:

[0007] The beam splitting laser source module is used to generate multi-aperture multi-beam splitting lasers.

[0008] The signal generation module is used to receive multiple beams of laser light and generate different modulation signals, and use the different modulation signals to modulate different beams of laser light respectively;

[0009] A multi-aperture emission module is used to coherently combine the modulated split laser beam and collimate the combined beam at the optical axis for output.

[0010] The signal demodulation module is located at the optical axis of the far-field target plate and is used to demodulate the modulated split laser beams in the composite beam to obtain split laser beams that deviate from the optical axis.

[0011] The marking feedback module is used to mark the split laser beams that deviate from the optical axis and feed them back to the optical axis processing module connected to the split laser source module, thereby realizing the detection of far-field light spots.

[0012] Furthermore, the beam-splitting laser source module is a seed source that outputs continuous laser light, splits the seed light into multiple beam-splitting lasers, and pre-amplifies the power of the multiple beam-splitting lasers to form a multi-aperture synthesized multi-beam-splitting laser.

[0013] Furthermore, the signal generating module includes interconnected components:

[0014] A signal generator is used to generate different modulated signals and send them to a phase modulator.

[0015] A phase modulator is used to receive the split laser beam and modulate the split laser beam using the modulation signal.

[0016] Furthermore, the signal demodulation module includes the following components connected in sequence:

[0017] The signal detection unit is used to convert the phase-modulated optical signal into a processable and measurable electrical signal and transmit it to the signal demodulation unit;

[0018] The signal demodulation unit is used to process the electrical signal and restore it to its original information.

[0019] Furthermore, the modulation signal includes at least two different modulation signals, each of which is used to modulate one or more of the split-beam lasers.

[0020] Furthermore, the modulation signal generated by the signal generator includes standard modulation signals and / or non-standard modulation signals.

[0021] Furthermore, the standard modulation signals include: sine wave, triangle wave, square wave, sawtooth wave, rectangular wave, noise, harmonics, pulse code modulation, and differential phase shift keying; the non-standard modulation signals include: pseudo-random code, sinc, exponential rising, exponential falling, electrocardiogram, Gaussian, semi-sine, and Lorentz.

[0022] Furthermore, the output modes of the modulation signal include: continuous wave, modulation, frequency sweep, burst, and sequence.

[0023] Furthermore, the number of the split laser beams is the same as the number of the phase modulators.

[0024] Furthermore, the modulation field applied to the split laser using a sinusoidal modulation signal is as follows: ;

[0025] The modulated split laser beam is: ;

[0026] in, Indicates the amplitude of the modulated electrical signal; Indicates the frequency of the modulated electrical signal; Indicates amplitude; Indicates the center frequency of the electromagnetic field; Indicates the modulation amplitude. , Indicates the amplitude of the modulated electrical signal. This represents the half-wave voltage of the phase modulator; It indicates the frequency of the modulated electrical signal.

[0027] In summary, this invention provides a multi-aperture coherent synthesis split-path phase modulation detection system. Compared with the prior art, the technical solution conceived by this invention can achieve the following beneficial effects:

[0028] (1) This invention uses different modulation signals to modulate the split laser beams of different paths. After the modulated split laser beams are combined, the modulated split laser beams in the combined beam are demodulated to obtain the split laser beams that deviate from the optical axis. Finally, the far-field offset beams are accurately marked and directly fed back to the optical axis processing module. By using the far-field spot of the multi-aperture combined beam for detection, the split laser beams that deviate from the optical axis can be accurately marked, and the offset beams can be accurately compensated directly according to the relevant algorithm. This improves the energy concentration of coherent synthesis in a simple and intuitive way. This method is highly operable and not only solves the problems of slow beam convergence and beam divergence in high-power multi-aperture emission, but also solves the problems of low compensation accuracy and efficiency in closed-loop correction during multi-aperture coherent synthesis.

[0029] (2) This invention uses different modulation signals to modulate the split laser beams of different paths. After demodulation, the position of each laser beam can be calculated and marked through data processing, and then fed back to the optical axis control module. Only one step is needed to adjust the optical axis control module. Marking the beams of multi-aperture coherent synthesis can reduce the algorithm time of coherent synthesis, avoid long convergence iterations, and greatly improve the focusing efficiency by reducing the number of compensations for the marked beams. It is fast and efficient.

[0030] (3) This invention generates a specific signal through a signal generator, which is then loaded onto a phase modulator to modulate a single-mode laser. For multi-aperture coherent combining systems, there is no need to change the optical path or add additional experimental equipment. It has a high compatibility with different multi-aperture coherent combining devices.

[0031] (4) Based on the phase modulation and demodulation of multiple beams, the present invention marks the composite beam with a signal and supplements it with a compensation algorithm. It can realize the accurate position identification and compensation calculation of the beam and complete the compensation in one go after identification, so as to realize the focusing and synthesis of coherent composite beam.

[0032] (5) The present invention uses a phase modulator in conjunction with a signal generator to apply different phase modulation signals to the aperture beam. After transmission through the transmitting device and long-distance free space, the modulated beam is demodulated at the target plate, so that the modulation signal mark of different beams can be identified, and the offset angle and distance of the beam can be confirmed.

[0033] (6) The modulation signal loaded by the present invention can be changed according to the number of synthetic apertures and the application scenario. It can be changed to a sine wave, a rectangular wave, or even a vector signal with angular quantum number, which has scalability and extensibility. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in this 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 some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the system composition of a multi-aperture coherent synthesis split-path phase modulation detection system provided by the present invention;

[0036] Figure 2 This is a schematic diagram of the optical field modulated by pseudo-random codes in a multi-aperture coherent synthesis split-path phase modulation detection system provided by the present invention.

[0037] Figure 3This is a schematic diagram of the synthesized aperture cross-section of a multi-aperture coherent synthesis split-path phase modulation detection system provided by the present invention;

[0038] Figure 4 This is a schematic diagram of the laser modulation drive signal waveform of a multi-aperture coherent synthesis split-path phase modulation detection system provided by the present invention;

[0039] 1-Beam splitting laser source module; 2-Signal generation module; 3-Multi-aperture emission module; 4-Signal demodulation module; 5-Marker feedback module. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0041] It should be noted that, in the description of the embodiments of the present invention, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a method, step, or system that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to the method, step, or system. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the method, step, or system that includes said element.

[0042] like Figure 1 As shown, this invention provides a multi-aperture coherent combining split-path phase modulation detection system. The system, along the optical path, sequentially includes: a split-beam laser source module for generating multi-aperture multi-path split-beam lasers; a signal generation module for receiving the multi-path split-beam lasers and generating different modulation signals, and using these different modulation signals to modulate different paths of the split-beam lasers; a multi-aperture emission module for coherently combining the modulated split-beam lasers and collimating the combined beam at the optical axis; a signal demodulation module, located at the optical axis of a far-field target plate, for demodulating the modulated split-beam lasers in the combined beam to obtain split-beam lasers deviating from the optical axis; and a marking feedback module for marking the deviating split-beam lasers and feeding them back to the optical axis processing module connected to the split-beam laser source module, thereby achieving the detection of far-field light spots.

[0043] As one example, firstly, a single-frequency laser is split into identical laser beams by an optical fiber beam splitter; then, different signals are modulated onto the different laser beams by devices such as an acousto-optic modulator or an electro-optic modulator, modulating the intensity, frequency, or phase of the original laser; next, the modulated lasers are combined coherently by a multi-aperture coherent combining device, thereby generating interference and ensuring stable output of the laser signal; finally, the modulated coherent lasers are demodulated individually on a far-field detector, mapping the corresponding modulated beams one by one.

[0044] This invention introduces a split-beam laser source into the detection system of the multi-aperture coherent combining system under test. Different modulation signals are applied to different split laser beams through signal modulators in each channel. After passing through the combining aperture, the beams are emitted. Then, at the far-end target plate, the signals of each beam are demodulated through signal traversal, and different beams are marked in the marking feedback module. The marked coherent beams, aided by a corresponding algorithm, can converge rapidly within a few passes, significantly improving the coherent combining effect of high-power lasers and effectively reducing the influence of mechanical and turbulent factors. This not only solves the problems of slow beam convergence and indistinguishable beam divergence effects in high-power multi-aperture emission, but also addresses the low compensation accuracy and efficiency issues in closed-loop correction during multi-aperture coherent combining.

[0045] The beam splitting laser source module serves as the system's light source and is connected to the signal generation module. It refers to a coherent combining light source that requires marking of multi-aperture coherently combined beams, i.e., n laser beams split from the same laser source by an optical fiber beam splitter.

[0046] As an embodiment of the present invention, the beam splitting laser source module outputs continuous laser light from a seed source, splits the seed light into multiple beam split lasers, and pre-amplifies the power of the multiple beam split lasers to form a multi-aperture synthesized multi-beam split laser.

[0047] Furthermore, it connects to the phase modulator in the signal generation module. The number of split laser beams matches the number of phase modulators.

[0048] The signal generation module, located after the beam splitting laser source module, is used to receive multiple beam splitting lasers, generate different modulation signals, and use the different modulation signals to modulate different beam splitting lasers respectively.

[0049] It should be noted that the modulation of multi-aperture beams mainly relies on specific modulators. These modulators can change the beam during its propagation. Modulators typically use electrical, acoustic, or magnetic methods to change certain characteristics of the beam, such as intensity, phase, and polarization state.

[0050] Specifically, the modulation of multi-aperture beams can be achieved in various ways, including spatial light modulation, liquid crystal modulation, grating modulation, etc. These modulation methods can modulate each sub-beam independently, thereby realizing a more complex spatial light field.

[0051] As an embodiment of the present invention, the signal generation module includes a signal generator and a phase modulator that are interconnected.

[0052] A signal generator is used to generate different modulated signals and send them to a phase modulator.

[0053] A phase modulator is used to receive split laser beams and modulate the split laser beams using a modulation signal.

[0054] It should be noted that the modulation signals mainly include one or more of the following: sinusoidal phase modulation, white noise (WNS) modulation, pseudo-random bit sequence (PRBS) modulation, piecewise parabolic signal (PPS) modulation, and multi-phase coded signal modulation.

[0055] When the phase modulator is driven by a pseudo-random code (PRBS), the resulting optical power spectral density contains discrete periodic characteristics. As a specific example, such as... Figure 2 The image shown is a schematic diagram of the optical field modulated by pseudo-random codes.

[0056] The white noise source (WNS) phase modulation method is implemented by filtering through a passband filter and then amplifying by a radio frequency (RF) amplifier to drive an electro-optic modulator.

[0057] The initial WNS is a relevant increment in the following sense:

[0058]

[0059]

[0060] The modulated laser passes through a combined aperture, resulting in coherent synthesis and providing a stable coherent light source.

[0061] Preferably, the modulation signal includes at least two different modulation signals, each of which is used to modulate one or more split-beam lasers.

[0062] For example, five different modulation signals can be applied to five different split laser beams. That is, different modulation signals are used to modulate different beams separately, with each beam using a different modulation signal. Alternatively, two different modulation signals can be used to modulate the five split laser beams; three beams can use the first modulation signal, and the other two can use the second modulation signal; or one beam can use the first modulation signal, three beams can use the second modulation signal, and the last beam can use both modulation signals.

[0063] It should be noted that the modulation signals generated by the signal generator include standard modulation signals and / or non-standard modulation signals. That is to say, different modulation signals are used to modulate different beams of laser light. These different modulation signals can be different standard modulation signals, different non-standard modulation signals, or both standard and non-standard modulation signals can be used simultaneously to modulate different beams of laser light.

[0064] As an example, standard modulation signals include: sine wave, triangle wave, square wave, sawtooth wave, rectangular wave, noise, harmonics, pulse code modulation, and differential phase shift keying.

[0065] As an example, non-standard modulation signals include: pseudo-random code, sinc, exponential rise, exponential fall, electrocardiogram, Gaussian, semi-sine, and Lorentz.

[0066] Furthermore, the output modes of the modulated signal include: continuous wave, modulation, frequency sweep, burst, and sequence.

[0067] The multi-aperture emission module is used to coherently combine the modulated split laser beams and collimate the combined beam at the optical axis. More specifically, located after the signal generation module, there is an array of beam collimators to ensure that multiple beams can be collimated and output through the beam collimators, and to complete coherent combining.

[0068] like Figure 3 The diagram shown is a schematic of a synthetic aperture cross-section. The multi-aperture emitter performs co-aperture emission, which, after long-distance transmission, connects to the demodulation module at the far-field target plate.

[0069] The signal demodulation module is located at the optical axis of the far-field target plate and is coaxial with the laser source emission axis. After the modulated laser beam has been transmitted over a long distance, it can demodulate the modulated beam of each channel. In other words, it is used to demodulate the modulated split laser beams in the composite beam separately to obtain split laser beams that deviate from the optical axis.

[0070] It should be noted that laser demodulation is the inverse process of laser modulation, and its purpose is to recover the loaded information from the modulated laser beam.

[0071] The target plate, located at the far-field optical axis of free-space transmission, is a beam receiving and detection device for coherently synthesized far-field beams. It receives the synthesized beam, and a beam splitter in front of the target plate separates a small portion of the light for the demodulation module. The demodulation module then sends the demodulated signal to the feedback marker module.

[0072] Demodulation methods include optical demodulation and electronic demodulation. Optical demodulation uses external optical devices, such as fiber optic gratings and optical spectrometers, to demodulate the signal; electronic demodulation uses specific circuits to process the signal, such as photodetectors.

[0073] As an embodiment of the present invention, the signal demodulation module includes a signal detection unit and a signal demodulation unit connected in sequence.

[0074] The signal detection unit converts the phase-modulated optical signal into a processable and measurable electrical signal and transmits it to the signal demodulation unit. For example, a photodetector, including but not limited to a PIN photodiode or an avalanche photodiode, can be used. When an optical signal shines on the detector, the detector converts the optical signal into a current or voltage signal.

[0075] A signal demodulation unit is used to process electrical signals to recover the original information. For example, for sinusoidal phase modulation, the demodulation process typically involves measuring the frequency and phase of the signal. A phase-locked loop (PPL) or a delay-locked loop (DLL) can be used. These loop structures can track the frequency and phase changes of the input signal, thereby accurately recovering the original information.

[0076] In addition, the signal demodulation module includes an error detection module to determine the difference between the demodulated signal and the original signal. It should be noted that this difference may be caused by various factors, such as distortion during modulation and demodulation, environmental noise, and errors in system components. The error detection module can use performance metrics such as bit error rate (BER) or signal-to-noise ratio (SNR) for detection and analysis, allowing for the evaluation and adjustment of system performance.

[0077] The demodulated signal from the demodulation module is connected to the processing module of the system optical axis via the feedback module.

[0078] The marking feedback module, located after the signal demodulation module, is used to mark the deviated laser beams and feed the information back to the optical axis processing module connected to the laser beam source module, thereby enabling the detection of far-field spots. In other words, it processes the demodulated, marked beam and feeds it back to the system's optical axis processing module.

[0079] It should be noted that the optical axis processing module, connected to the beam-splitting laser source module, is used to adjust the optical axis angle of the n laser beams. The optical axis processing module can be a fast-reflecting mirror or a piezoelectric driven positioner, etc.

[0080] This invention is applicable to the split-path phase modulation detection of multi-aperture coherent combining devices and can solve the problem of multi-beam marking in multi-aperture combining devices. Using a single-frequency laser as a carrier, different modulation signals are applied to modulate the beams separately. The beams are then demodulated at a far-field target plate. A one-to-one correspondence is established between the successfully demodulated beams and the exit pupil beams, thus achieving beam calibration for multi-aperture combining.

[0081] A single-frequency laser is an amplitude-stable quasi-monochromatic electromagnetic field, and its instantaneous electric field can be expressed as:

[0082] ;

[0083] in, Indicates amplitude, It represents the center frequency of the electromagnetic field.

[0084] The modulation field applied to the split laser by the signal generation module is as follows:

[0085] ;

[0086] in, Indicates the amplitude of the modulated electrical signal; It indicates the frequency of the modulated electrical signal.

[0087] The modulated split laser beam is then:

[0088] ;

[0089] in, Indicates amplitude; Indicates the center frequency of the electromagnetic field; Indicates the modulation amplitude. , Indicates the amplitude of the modulated electrical signal. This represents the half-wave voltage of the phase modulator; It indicates the frequency of the modulated electrical signal.

[0090] In one specific embodiment, a high-power laser light source using multi-aperture coherent synthesis of the present invention is used as the beam. The laser operating wavelength is 1064nm, the output power is 0-5W, the number of array units is 7, the single aperture diameter is 55mm, the spacing between adjacent apertures is 60mm, the electro-optic modulator is a Photline / IXBLUE NIR-MPX-LN-02 lithium niobate (LiNbO3) phase modulator, and the far-field demodulator uses a SAM 1080 fiber grating demodulator, i.e., as shown below. Figure 4 The waveform of the laser modulation drive signal is shown.

[0091] In summary, this invention is particularly applicable to the split-path phase modulation detection of multi-aperture coherent combining devices, and is used for far-field spot detection of multi-aperture combined beams. The purpose is to solve the problem of inaccurate control of multi-aperture beams in multi-aperture coherent combining systems, as well as the problem that the beams from the exit pupil position and the beams at the far-field target plate cannot be matched one-to-one, making it impossible to directionally adjust specific beams. This invention, through the interaction of the beam splitting laser source module, signal generation module, multi-aperture emission module, signal demodulation module, and marking feedback module, can accurately mark the combined beam and accurately compensate for the offset beams according to relevant algorithms.

[0092] It should be noted that, for the sake of simplicity, the foregoing embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0093] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0094] In the several embodiments provided in this application, it should be understood that the disclosed methods or systems can be implemented in other ways. For example, the embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed.

[0095] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0096] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0097] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage device. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application.

[0098] Those skilled in the art will understand that all or part of the circuits in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, which may include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, etc.

[0099] The foregoing description is merely an exemplary embodiment of this disclosure and should not be construed as limiting the scope of this disclosure. Any equivalent changes and modifications made in accordance with the teachings of this disclosure shall still fall within the scope of this disclosure. Those skilled in the art will readily conceive of embodiments of this disclosure upon considering the specification and practicing the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not described herein. The specification and embodiments are to be considered exemplary only, and the scope and spirit of this disclosure are defined by the claims.

[0100] 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.

[0101] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A multi-aperture coherent synthesis split-path phase modulation detection system, characterized in that, The system, along the optical path, comprises, in sequence: The beam splitting laser source module is used to generate multi-aperture multi-beam splitting lasers. The signal generation module is used to receive multiple beams of laser light and generate different modulation signals, and use the different modulation signals to modulate different beams of laser light respectively; The multi-aperture emission module employs an array of beam collimators for common-aperture emission, which is used to coherently combine the modulated split laser beams and collimate the combined beams at the optical axis for output. The signal demodulation module is located at the optical axis of the far-field target plate and is used to demodulate the modulated split laser beams in the composite beam to obtain split laser beams that deviate from the optical axis. The marking feedback module is used to mark the position of the split laser beam that deviates from the optical axis, confirm the angle and distance of the beam deviation, and feed it back to the optical axis processing module connected to the split laser source module. The optical axis processing module is used to adjust the optical axis angle of the multiple laser beams, thereby realizing the detection of the far-field spot.

2. The multi-aperture coherent synthesis split-path phase modulation detection system according to claim 1, characterized in that, The beam splitting laser source module is a seed source that outputs continuous laser light. The seed light is split into multiple beam splitting lasers. The power of the multiple beam splitting lasers is pre-amplified to form a multi-aperture synthesized multi-beam splitting laser.

3. The multi-aperture coherent synthesis split-path phase modulation detection system according to claim 1, characterized in that, The signal generation module includes interconnected components: A signal generator is used to generate different modulated signals and send them to a phase modulator. A phase modulator is used to receive the split laser beam and modulate the split laser beam using the modulation signal.

4. The multi-aperture coherent synthesis split-path phase modulation detection system according to claim 1, characterized in that, The signal demodulation module comprises, in sequence, the following: The signal detection unit is used to convert the phase-modulated optical signal into a processable and measurable electrical signal and transmit it to the signal demodulation unit; The signal demodulation unit is used to process the electrical signal and restore it to its original information.

5. The multi-aperture coherent synthesis split-path phase modulation detection system according to claim 1, characterized in that, The modulation signal includes at least two different modulation signals, each of which is used to modulate one or more of the split laser beams.

6. The multi-aperture coherent synthesis split-path phase modulation detection system according to claim 3, characterized in that, The modulated signal generated by the signal generator includes standard modulated signals and / or non-standard modulated signals.

7. The multi-aperture coherent synthesis split-path phase modulation detection system according to claim 6, characterized in that, The standard modulation signals include: sine wave, triangle wave, square wave, sawtooth wave, rectangular wave, noise, harmonics, pulse code modulation, and differential phase shift keying; the non-standard modulation signals include: pseudo-random code, sinc, exponential rising, exponential falling, electrocardiogram, Gaussian, semi-sine, and Lorentz.

8. A multi-aperture coherent synthesis split-path phase modulation detection system according to any one of claims 5 to 7, characterized in that, The output modes of the modulation signal include: continuous wave, modulation, frequency sweep, burst, and sequence.

9. The multi-aperture coherent synthesis split-path phase modulation detection system according to claim 3, characterized in that, The number of split laser beams is the same as the number of phase modulators.

10. A multi-aperture coherent synthesis split-path phase modulation detection system according to claim 7, characterized in that, The modulation field applied to the split laser using a sinusoidal modulation signal is as follows: ; The modulated split laser beam is: ; in, Indicates the amplitude of the modulated electrical signal; Indicates the frequency of the modulated electrical signal; Indicates amplitude; Indicates the center frequency of the electromagnetic field; Indicates the modulation amplitude. , Indicates the amplitude of the modulated electrical signal. This represents the half-wave voltage of the phase modulator; It indicates the frequency of the modulated electrical signal.

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