All-optical radar image target recognition system and method based on MZI

Abstract

The invention provides an MZI-based all-optical radar image target recognition system and method, and the system comprises a laser light source which is used for transmitting laser; the beam splitter is used for splitting the received laser into N paths of laser with equal power; the detection array is used for converting the target image information into n1 paths of radar receiving signals; the MZI modulation array is used for modulating n1 paths of radar receiving signals to N paths of laser and outputting M paths of modulated laser; the phase control unit is used for outputting n2 paths of control signals; the MZI operation array is used for carrying out phase adjustment on the M paths of modulated laser according to n2 paths of control signals and outputting n paths of adjusted laser; and the photoelectric conversion unit is used for converting the n paths of adjusted laser into n paths of electric signals, and identifying and classifying the target image information according to the n paths of electric signals. The technical problem that hardware computing power of electronic computing of a recognition system in the prior art is difficult to greatly improve can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of all-optical computing processing and image target recognition, and in particular to an MZI-based all-optical radar image target recognition system and method. Background Art

[0002] As an important means of perceiving information about surrounding targets, radar is irreplaceable in military and civilian fields. All countries have invested a lot of energy in extensive research, and radar technology has developed rapidly, and its functions have become increasingly powerful. At present, the application scenarios and surrounding environments of radar are becoming increasingly complex. It is not only required to have basic functions such as obtaining target position, orientation, and size, but also to have the ability to identify targets. Radar automatic target recognition technology has emerged and has become a research hotspot in this field. In recent years, with the substantial improvement of computing power, storage technology and parallel computing technology have reached unprecedented heights of development, and the theories and methods of machine learning represented by neural networks have made continuous breakthroughs. Radar target recognition technology based on neural network algorithms has become a new research direction. Studies have shown that radar target recognition methods based on neural network algorithms have the advantages of being fast and accurate compared to traditional recognition methods, and have good adaptability to complex signal sources and low signal-to-noise ratio environments.

[0003] The application of neural network algorithms will greatly improve performance indicators such as target recognition accuracy, but its algorithm structure is complex, and there are a lot of floating-point operations during operation. The powerful functions require high-performance computing power as support, and the deployment of advanced neural network algorithms puts higher requirements on the computing power of hardware. At present, the hardware running neural networks mainly includes graphics processing units (GPUs), field programmable gate arrays (FPGAs), digital signal processors (DSPs), application specific integrated circuits (ASICs), and tensor processors (TPUs). However, these hardware based on traditional electronic computing technology use traditional COMS processes. Limited by Moore's Law, their computing power, cost, and power consumption will be difficult to be significantly optimized. Summary of the invention

[0004] The present invention provides a full optical radar image target recognition system and method based on Mach-Zenhder Interferometer (MZI), which can solve the technical problem that the hardware computing power of the electronic calculation of the recognition system in the prior art is difficult to be significantly improved.

[0005] According to one aspect of the present invention, a full optical radar image target recognition system based on MZI is provided, the system comprising:

[0006] A laser light source, used for emitting laser;

[0007] A beam splitter is used to split the received laser into N lasers with equal power;

[0008] The detection array is used to convert the target image information into n1 radar receiving signals;

[0009] The MZI modulation array is used to receive N lasers and n1 radar receiving signals, and is also used to modulate the n1 radar receiving signals onto the N lasers, and output M modulated lasers;

[0010] A phase control unit, used for outputting n2 control signals;

[0011] The MZI operation array is used to receive M-channel modulated lasers and n2-channel control signals, and is also used to adjust the phase of the M-channel modulated lasers according to the n2-channel control signals, and output n-channel adjusted lasers;

[0012] The photoelectric conversion unit is used to convert n regulated lasers into n electrical signals, and realize the recognition and classification of target image information according to the n electrical signals.

[0013] Preferably, the MZI modulation array includes n1 MZI units, and the n1 MZI units are arranged in multiple columns. The number of the MZI units in each column increases by one in an arithmetic progression, and each of the MZI units is connected to two adjacent MZI units in the following column through an optical waveguide, and the number of the MZI units in the first column is N / 2, and the number of the MZI units in the last column is M / 2.

[0014] Preferably, the MZI operation array includes n2 MZI units, the n2 MZI units are arranged in multiple columns, the number of the MZI units in each column decreases by one in an arithmetic progression, each of the MZI units is connected to two adjacent MZI units in the next column through an optical waveguide, and the number of the MZI units in the first column is M / 2, and the number of the MZI units in the last column is n / 2.

[0015] Preferably, n1 is obtained by the following formula:

[0016] n1=(M+N)(M-N+2) / 8.

[0017] Preferably, n2 is obtained by the following formula:

[0018] n2=(M+n)(M-n+2) / 8.

[0019] Preferably, the MZI unit includes a 50:50 first beam splitter, a 50:50 second beam splitter and a phase modulation module, wherein the first beam splitter is used to receive two incident lasers and output two lasers; the phase modulation module is used to receive one laser and one electrical signal output by the first beam splitter, and is also used to phase modulate one laser output by the first beam splitter according to the current electrical signal, and output one laser after the phase change; the second beam splitter is used to receive one laser after the phase change and another laser output by the first beam splitter, and output two lasers; wherein, when the MZI unit belongs to the MZI modulation array, the electrical signal is a radar reception signal; when the MZI unit belongs to the MZI operation array, the electrical signal is a control signal.

[0020] Preferably, the laser light source is a semiconductor laser or a fiber laser.

[0021] Preferably, the detection array adopts an optical imaging radar.

[0022] Preferably, the phase control unit is a multi-channel voltage source.

[0023] According to another aspect of the present invention, a method for image target recognition based on MZI is provided, wherein the method adopts any of the above-mentioned systems to perform image target recognition, and the method comprises:

[0024] The laser light source emits laser light;

[0025] The beam splitter divides the received laser into N lasers with equal power;

[0026] The detection array converts the target image information into n1 radar receiving signals;

[0027] The MZI modulation array receives N lasers and n1 radar receiving signals, modulates the n1 radar receiving signals onto N lasers, and outputs M modulated lasers;

[0028] The phase control unit outputs n2 control signals;

[0029] The MZI operation array receives M-channel modulated lasers and n2-channel control signals, performs phase adjustment on the M-channel modulated lasers according to the n2-channel control signals, and outputs n-channel adjusted lasers;

[0030] The photoelectric conversion unit converts n regulated lasers into n electrical signals, and recognizes and classifies the target image information according to the n electrical signals.

[0031] By applying the technical solution of the present invention, according to the principles of laser interference, laser phase modulation and optical neural network, the radar receiving signal output by the detection array is directly modulated onto the N-channel laser phase, and classified through the optical network to realize all-optical operation of radar signal processing, thereby improving the accuracy of radar target recognition and reducing the radar operation power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The included drawings are used to provide a further understanding of the embodiments of the present invention, which constitute a part of the specification, are used to illustrate the embodiments of the present invention, and together with the text description, explain the principles of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 A schematic diagram of the structure of a full optical radar image target recognition system based on MZI is shown according to an embodiment of the present invention;

[0034] Figure 2 Shows Figure 1 Schematic diagram of the structure of the MZI modulation array;

[0035] Figure 3 Shows Figure 2 Schematic diagram of the structure of the MZI unit;

[0036] Figure 4 Shows Figure 1 Schematic diagram of the structure of the MZI operation array.

[0037] The above drawings include the following reference numerals:

[0038] 1. Laser light source; 2. Beam splitter; 3. MZI modulation array; 4. Detection array; 5. MZI operation array; 6. Phase control unit; 7. Photoelectric conversion unit; 8. First beam splitter; 9. Second beam splitter; 10. Phase modulation module. DETAILED DESCRIPTION

[0039] It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0041] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0042] like Figure 1 As shown, the present invention provides a full optical radar image target recognition system based on MZI, and the system includes:

[0043] A laser light source 1, used for emitting laser light;

[0044] The beam splitter 2 is used to split the received laser into N laser beams with equal power. Figure 1 Medium laser 2-1, 2-2, ..., 2-(N-1), 2-N;

[0045] The detection array 4 is used to convert the target image information into n1 radar receiving signals, such as Figure 1 Middle signals 4-1, 4-2, ..., 4-(n1-1), 4-n1;

[0046] The MZI modulation array 3 is used to receive N lasers and n1 radar receiving signals, and is also used to modulate the n1 radar receiving signals onto N lasers and output M modulated lasers. Figure 1 Medium laser 3-1, 3-2, ..., 3-(M-1), 3-M;

[0047] The phase control unit 6 is used to output n2 control signals, such as Figure 1Middle signals 6-1, 6-2, ..., 6-(n2-1), 6-n2;

[0048] The MZI operation array 5 is used to receive M-channel modulated lasers and n2-channel control signals, and is also used to adjust the phase of the M-channel modulated lasers according to the n2-channel control signals, and output n-channel adjusted lasers, such as Figure 1 Medium laser 5-1, 5-2, ..., 5-(n-1), 5-n;

[0049] The photoelectric conversion unit 7 is used to convert the n-channel regulated laser light into n-channel electrical signals, such as Figure 1 The middle signals 7-1, 7-2, ..., 7-(n-1), 7-n realize the recognition and classification of the target image information according to the n-way electrical signals.

[0050] According to the principles of laser interference, laser phase modulation and optical neural network, the present invention directly modulates the radar receiving signal output by the detection array 4 onto the N-channel laser phase, and realizes all-optical operation of radar signal processing through optical network classification, thereby improving the accuracy of radar target recognition and reducing the radar operation power consumption.

[0051] In the present invention, the laser light source 1, the beam splitter 2, the MZI modulation array 3, the MZI operation array 5, and the detection array 4 are arranged in sequence and connected through an optical waveguide; the detection array 4 is connected to the MZI modulation array 3 through a circuit; and the phase control unit 6 is connected to the MZI operation array 5 through a circuit.

[0052] According to an embodiment of the present invention, the laser light source 1 is a semiconductor laser or a fiber laser.

[0053] Specifically, the laser light source 1 outputs monochromatic light with a wavelength of 1550 nm and a line width of less than 500 kHz, ensuring that it has a long coherence length.

[0054] According to an embodiment of the present invention, the beam splitter 2 is a waveguide beam splitter having one input port and N output ports. The value of the number of output ports N is related to the detection array 4 and the type of target to be identified. After passing through the beam splitter 2, the laser is divided into N beams of equal power.

[0055] According to one embodiment of the present invention, the detection array 4 adopts an optical imaging radar having n1 output ports, which converts the detected image information into radar receiving signals, that is, electrical signals 4-1, 4-2, ..., 4-(n1-1), 4-n1 and modulates the laser, wherein n1 is related to the size of the detection array 4.

[0056] According to an embodiment of the present invention, Figure 2As shown, the MZI modulation array 3 has N optical input ports, M optical output ports and n1 circuit input ports, and specifically includes n1 MZI units. Figure 2 Each intersection represents an MZI unit, and n1 MZI units are arranged in multiple columns. The number of the MZI units in each column increases by one in an arithmetic progression. Each of the MZI units is connected to two adjacent MZI units in the next column through an optical waveguide. The number of the MZI units in the first column is N / 2, the number of the MZI units in the second column is N / 2+1, the number of the MZI units in the third column is N / 2+2, ..., and so on. The number of the MZI units in the last column is M / 2.

[0057] The input ends of the N / 2 MZI units in the first column are used to receive N laser beams, and the output ends of the M / 2 MZI units in the last column are used to output M modulated laser beams.

[0058] n1 is selected so that (M+N)(M-N+2) / 8=n1 holds true, to ensure that each radar receiving signal in the detection array 4 modulates the laser. In a specific implementation, n1 can be 164645, N can be 512, and M can be 1256.

[0059] Specifically, the MZI unit includes a 50:50 first beam splitter 8, a 50:50 second beam splitter 9 and a phase modulation module 10, wherein the first beam splitter 8 is used to receive two incident lasers and output two lasers; the phase modulation module 10 is used to receive one laser and one electrical signal output by the first beam splitter 8, and is also used to phase modulate one laser output by the first beam splitter 8 according to the current electrical signal, and output one laser after the phase is changed; the second beam splitter 9 is used to receive one laser after the phase is changed and another laser output by the first beam splitter 8, and output two lasers; wherein, when the MZI unit belongs to the MZI modulation array 3, the electrical signal is a radar receiving signal; when the MZI unit belongs to the MZI operation array 5, the electrical signal is a control signal.

[0060] For example, Figure 3 As shown, taking an MZI unit in the MZI modulation array 3 as an example, assuming that the two input laser field intensities are E 11-in and E 21-in , and there are:

[0061]

[0062]

[0063] Where E0 is the input laser field intensity component, ω is the laser circular frequency, t is time, i is an imaginary number, φ 10 ,φ 20 are the initial phases of the two incident laser beams. After passing through the first beam splitter 8, the field intensities are E 11-out and E 21-out , then:

[0064]

[0065]

[0066] The phase modulation module 10 can be an electro-optical modulation crystal. Under the action of the electrical signal V, the phase changes by φ v , then the two laser beams incident on the second beam splitter 9 have a field intensity E 12-in and E 22-in They are:

[0067]

[0068]

[0069] After the second beam splitter 9, the two laser beams are output with field intensities of E 12-out and E 22-out :

[0070]

[0071]

[0072] It can be seen that the output laser is modulated by the electrical signal, thereby realizing the modulation of the input laser by signals 4-1, 4-2, ..., 4-(n1-1), 4-n1.

[0073] According to an embodiment of the present invention, the phase control unit 6 is a multi-channel voltage source. The voltage of each channel is generated through training, that is, the control signal is a trained electrical signal, which can be trained using an existing training method, which will not be described in detail in the present invention.

[0074] According to an embodiment of the present invention, Figure 4 As shown, the MZI operation array 5 has M optical input ports, n optical output ports and n2 parameter control ports, and specifically includes n2 MZI units. Figure 4Each intersection represents an MZI unit, and n2 MZI units are arranged in multiple columns. The number of the MZI units in each column decreases by one in an arithmetic progression. Each of the MZI units is connected to two adjacent MZI units in the next column through an optical waveguide. The number of the MZI units in the first column is M / 2, the number of the MZI units in the second column is M / 2-1, the number of the MZI units in the third column is M / 2-2, ..., and so on. The number of the MZI units in the last column is n / 2.

[0075] Specifically, the input ends of the M / 2 MZI units in the first column are used to receive M-channel modulated lasers, and the output ends of the n / 2 MZI units in the last column are used to output n-channel modulated lasers.

[0076] n2 is selected so that (M+n)(M-n+2) / 8=n2 holds true, to ensure that each control signal in the phase control unit 6 adjusts the laser. In a specific implementation, n=10, M=1256, then n2 can be 197496.

[0077] Wherein, n is the number of classification categories of target image information. After the laser passes through the MZI operation array 5, images of the same category will be output from the same output port, and images of different categories will be output from different output ports, thereby obtaining n beams of laser light with different phases and powers, thereby realizing image classification.

[0078] The present invention also provides a method for full optical radar image target recognition based on MZI, the method adopts any of the above-mentioned systems to perform image target recognition, and the method comprises:

[0079] The laser light source 1 emits laser;

[0080] The beam splitter 2 splits the received laser into N lasers with equal power;

[0081] The detection array 4 converts the target image information into n1 radar receiving signals;

[0082] The MZI modulation array 3 receives N lasers and n1 radar receiving signals, modulates the n1 radar receiving signals onto the N lasers, and outputs M modulated lasers;

[0083] The phase control unit 6 outputs n2 control signals;

[0084] The MZI operation array 5 receives M-channel modulated lasers and n2-channel control signals, performs phase adjustment on the M-channel modulated lasers according to the n2-channel control signals, and outputs n-channel adjusted lasers;

[0085] The photoelectric conversion unit 7 converts the n regulated laser beams into n electrical signals, and recognizes and classifies the target image information according to the n electrical signals.

[0086] In summary, the present invention provides a full-optical radar image target recognition system and method based on MZI. According to the principles of laser interference, laser phase modulation and optical neural network, the radar receiving signal output by the detection array 4 is directly modulated onto the N-channel laser phase, and through optical network classification, the full-optical operation of radar signal processing is realized, thereby improving the accuracy of radar target recognition and reducing the radar operation power consumption.

[0087] Parts of the present invention that are not described in detail are well known to those skilled in the art.

[0088] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0089] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0090] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A full optical radar image target recognition system based on MZI, characterized in that: The system comprises: A laser light source, used for emitting laser; A beam splitter is used to split the received laser into N lasers with equal power; The detection array is used to convert the target image information into n1 radar receiving signals; The MZI modulation array is used to receive N lasers and n1 radar receiving signals, and is also used to modulate the n1 radar receiving signals onto the N lasers, and output M modulated lasers; A phase control unit, used for outputting n2 control signals; The MZI operation array is used to receive M-channel modulated lasers and n2-channel control signals, and is also used to adjust the phase of the M-channel modulated lasers according to the n2-channel control signals, and output n-channel adjusted lasers; The photoelectric conversion unit is used to convert n regulated lasers into n electrical signals, and realize the recognition and classification of target image information according to the n electrical signals.

2. The system according to claim 1, characterized in that The MZI modulation array includes n1 MZI units, which are arranged in multiple columns. The number of the MZI units in each column increases by one in an arithmetic progression. Each of the MZI units is connected to two adjacent MZI units in the next column through an optical waveguide, and the number of the MZI units in the first column is N / 2, and the number of the MZI units in the last column is M / 2.

3. The system according to claim 1, characterized in that The MZI operation array includes n2 MZI units, which are arranged in multiple columns. The number of MZI units in each column decreases by one in an arithmetic progression. Each of the MZI units is connected to two adjacent MZI units in the next column through an optical waveguide, and the number of the MZI units in the first column is M / 2, and the number of the MZI units in the last column is n / 2.

4. The system according to claim 2, characterized in that n1 is obtained by the following formula: n1=(M+N)(M-N+2) / 8.

5. The system according to claim 3, characterized in that n2 is obtained by the following formula: n2=(M+n)(M-n+2) / 8.

6. The system according to claim 2 or 3, characterized in that: The MZI unit includes a 50:50 first beam splitter, a 50:50 second beam splitter and a phase modulation module, wherein the first beam splitter is used to receive two incident lasers and output two lasers; the phase modulation module is used to receive one laser and one electrical signal output by the first beam splitter, and is also used to phase modulate one laser output by the first beam splitter according to the current electrical signal, and output one laser after the phase is changed; the second beam splitter is used to receive one laser after the phase is changed and another laser output by the first beam splitter, and output two lasers; wherein, when the MZI unit belongs to the MZI modulation array, the electrical signal is a radar reception signal; when the MZI unit belongs to the MZI operation array, the electrical signal is a control signal.

7. The system according to claim 1, characterized in that The laser light source is a semiconductor laser or a fiber laser.

8. The system according to claim 1, characterized in that The detection array adopts optical imaging radar.

9. The system according to any one of claims 1 to 8, characterized in that: The phase control unit is a multi-channel voltage source.

10. A method for target recognition in full optical radar images based on MZI, characterized in that: The method uses any system described in claims 1-9 to perform image target recognition, and the method comprises: The laser light source emits laser light; The beam splitter divides the received laser into N lasers with equal power; The detection array converts the target image information into n1 radar receiving signals; The MZI modulation array receives N lasers and n1 radar receiving signals, modulates the n1 radar receiving signals onto N lasers, and outputs M modulated lasers; The phase control unit outputs n2 control signals; The MZI operation array receives M-channel modulated lasers and n2-channel control signals, performs phase adjustment on the M-channel modulated lasers according to the n2-channel control signals, and outputs n-channel adjusted lasers; The photoelectric conversion unit converts n regulated lasers into n electrical signals, and recognizes and classifies the target image information according to the n electrical signals.

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