Light beam projection device, control method, upper computer and storage medium
By detecting the polarization state of the incident light and using multi-layered metasurfaces for phase control, the lidar detection mode can be flexibly switched, which solves the problem of lidar's lack of flexibility and adaptability in complex environments and improves the system's environmental adaptability. level of flexibility and integration.
Patent Information
- Application Number
- CN202411611366.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-12
- Publication Date
- 2025-01-21
AI Technical Summary
Lidar can only achieve a single detection mode, with poor flexibility and adaptability, making it difficult to effectively perceive and adapt in complex environments.
By detecting the polarized state of the light, the phase control of the multi -layer hyper structure is used to achieve the flexible switching of the dot -matrix structure light or a large range of beam projection.
The flexibility and adaptability of laser radar in complex environments have been realized, and the limitations of single -mode laser radar in complex environments have been overcome, and the integration and miniaturization of lidar technology is promoted.
Smart Images
Figure CN119335505A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of laser radar technology, and in particular to a light beam projection device, a control method, a host computer and a storage medium. Background Art
[0002] LiDAR 3D imaging is a typical active imaging technology. Compared with imaging technology based on image sensors, it has the advantages of being able to directly obtain depth information and having strong anti-interference capabilities. It plays a vital role in the fields of unmanned driving, intelligent robots, and drone navigation. LiDAR uses laser as a carrier and actively emits pulsed laser beams to process the echoes reflected or scattered by the target, and then obtains the 3D information of the target in conjunction with a certain scanning or snapshot imaging method. In order to improve the ability to adapt to complex environments, LiDAR technology is developing in the direction of miniaturization, high-function integration, and enhanced environmental adaptability.
[0003] At present, according to the difference in the detection mechanism of the transmitting end, LiDAR can be divided into two categories: dot matrix structured light scanning type and Flash snapshot type. Scanning LiDAR is usually equipped with movable components such as two-dimensional rotating mirrors or micro-electromechanical systems. It projects a dot matrix structured laser beam and controls it for high-speed scanning to achieve high-precision three-dimensional imaging. This type of LiDAR exhibits high detection accuracy and long detection distance due to its point detection characteristics. However, the need for scanning leads to relatively low detection efficiency. At the same time, the use of movable components also restricts the integration level and service life of the system. In contrast, Flash LiDAR abandons the complex and high-frequency rotating mechanical structure and has attracted widespread attention due to its unique advantages of snapshot detection. Its working principle is similar to that of a flashlight, projecting laser to a large area in a short time, and then using a high-sensitivity receiver to construct a three-dimensional image. However, due to the need to achieve a large range of laser projection, Flash LiDAR is significantly limited in power density and detection distance, and its detection accuracy is also lower than that of scanning LiDAR. To sum up, whether it is the dot matrix structured light projection mode or the Flash large-range beam projection mode, their single detection methods have limited the flexibility and adaptability of lidar to different degrees when facing different environmental perception needs. Summary of the invention
[0004] The present application provides a beam projection device, a control method, a host computer and a storage medium to solve the problems in the related art that the laser radar can only realize a single detection mode and has poor flexibility and adaptability.
[0005] A first aspect of the present application provides a light beam projection device, comprising: a device body and a light beam incident window; a multi-layer metasurface arranged in the device body, wherein the multi-layer metasurface is arranged behind the light beam incident window, and is used to perform phase control on incident light from the light beam incident window for at least one of lattice structured light projection and wide-range light beam projection; a detection component arranged on the device body, and is used to detect the polarization state of the incident light; and a host computer, and is used to determine the type of the incident light based on the polarization state, and control the multi-layer metasurface to perform phase control on the incident light based on the type, so as to achieve lattice structured light projection or wide-range light beam projection.
[0006] Optionally, the multi-layer metasurface includes a primary metasurface and a secondary metasurface, wherein the primary metasurface adopts a geometric phase unit and an arrayed phase design, and the secondary metasurface adopts a transmission phase unit and a non-arrayed phase design.
[0007] Optionally, the geometric phase unit is composed of a plurality of rectangular nanocolumns with variable angles of the same size, and the phase is controlled by controlling the angle of each rectangular nanocolumn with variable angles.
[0008] Optionally, the transmission phase unit is composed of circular nanocolumns with variable diameters, and phase regulation is performed by controlling the diameter of the circular nanocolumns with variable diameters.
[0009] Optionally, the host computer is further used to: if the type of incident light is left-handed circularly polarized light, control the first-level metasurface to focus the incident light into a lattice light beam, and control the second-level metasurface to adjust the exit deflection angle of the lattice light beam to achieve lattice structured light projection; if the type of incident light is right-handed circularly polarized light, control the first-level metasurface to adjust the right-handed circularly polarized light to the opposite phase of the incident light, so that the right-handed circularly polarized light diverges, and control the second-level metasurface to emit the divergent right-handed circularly polarized light to achieve large-scale light beam projection.
[0010] Optionally, the host computer is further used for: if the type of the incident light is left-handed circularly polarized light, the phase distribution of the geometric phase unit in the first-level metasurface is:
[0011]
[0012] in, x is the coordinate of the x-axis, y is the coordinate of the y-axis, i, j is the i-th row and j-th column, p is a negative real constant, (Γj, Γi) is the coordinate of the center position of the array unit, n m ×P m is the aperture size of the first-level metasurface, n m is the array size, P m is the arraying period, is the phase distribution of the array unit in the i-th row and j-th column of the first-level metasurface at (x, y);
[0013] The phase distribution of the transmission phase unit in the secondary metasurface is:
[0014]
[0015] in, is the phase distribution of the secondary metasurface at (x, y);
[0016] If the type of incident light is right-handed circularly polarized light, the phase distribution of the geometric phase unit in the metasurface is:
[0017]
[0018] in,
[0019] The phase distribution of the transmission phase unit in the secondary metasurface is the same as when the type of incident light is left-handed circularly polarized light.
[0020] A second aspect of the present application provides a control method for a light beam projection device, which is used to operate the light beam projection device of the above embodiment, and includes the following steps: acquiring the polarization state of incident light; determining the type of incident light based on the polarization state; and controlling the multi-layer metasurface to perform phase modulation on the incident light based on the type, so as to achieve dot matrix structured light projection or large-range light beam projection.
[0021] Optionally, the multi-layer metasurface includes a primary metasurface and a secondary metasurface, and the primary multi-layer metasurface is controlled to perform phase control on the incident light based on the type, including: if the type of the incident light is left-handed circularly polarized light, the primary metasurface is controlled to focus the incident light into a lattice light beam, and the secondary metasurface is controlled to control the exit deflection angle of the lattice light beam to achieve lattice structured light projection; if the type of the incident light is right-handed circularly polarized light, the primary metasurface is controlled to control the right-handed circularly polarized light to have a phase opposite to that of the incident light, so that the right-handed circularly polarized light diverges, and the secondary metasurface is controlled to emit the divergent right-handed circularly polarized light to achieve large-range light beam projection.
[0022] The third aspect of the present application provides a host computer, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor executes the program to execute a control method for a beam projection device as described in the above embodiment.
[0023] The fourth aspect of the present application provides a computer-readable storage medium on which a computer program or instruction is stored. The computer program or instruction is executed by a processor to perform a control method for a light beam projection device as described in the above embodiment.
[0024] Therefore, this application has at least the following beneficial effects:
[0025] The embodiment of the present application constructs a beam projection device, which can detect the polarization state of the incident light through the detection component. The upper computer determines the type of the incident light based on the polarization state, and controls the multi-layer metasurface to phase-regulate the incident light based on the type, so as to realize dot matrix structured light projection or large-scale beam projection, realizes beam projection of different modes based on the type of incident light, realizes flexible switching between the two modes, overcomes the flexibility limitation of the single-mode laser radar system in complex environments, increases the adaptability of the beam projection device in complex and changeable environments, and because of the use of multi-layer metasurfaces, the metasurfaces are small in size and light in weight, which can promote the laser radar technology to develop in the direction of higher level of integration and miniaturization. Therefore, the technical problems in the related technology that the laser radar can only realize a single detection mode and has poor flexibility and adaptability are solved.
[0026] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:
[0028] Figure 1 A schematic diagram of a light beam projection device provided according to an embodiment of the present application;
[0029] Figure 2 A schematic diagram of a primary metasurface provided according to an embodiment of the present application;
[0030] Figure 3 A schematic diagram of a secondary metasurface provided according to an embodiment of the present application;
[0031] Figure 4 A schematic diagram of the principle of a dot matrix structured light projection mode provided according to an embodiment of the present application;
[0032] Figure 5 It is a schematic diagram of the principle of the Flash wide-range light beam projection mode provided according to an embodiment of the present application;
[0033] Figure 6 A schematic diagram of a dot matrix structured light projection mode provided according to an embodiment of the present application;
[0034] Figure 7 A schematic diagram of a Flash large-range light beam projection mode provided according to an embodiment of the present application;
[0035] Figure 8A flowchart of a method for controlling a light beam projection device according to an embodiment of the present application;
[0036] Fig. 9 It is a schematic diagram of the structure of a host computer provided according to an embodiment of the present application. DETAILED DESCRIPTION
[0037] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.
[0038] The following describes the beam projection device, control method, host computer and storage medium of the embodiment of the present application with reference to the accompanying drawings. With respect to the dot matrix structured light projection mode or the Flash large-range beam projection mode mentioned in the background technology center, the single detection mode limits the flexibility and adaptability of the laser radar in the face of different environmental perception requirements to varying degrees. The present application provides a beam projection device, in which the polarization state of the incident light can be detected by the detection component, and the host computer determines the type of the incident light based on the polarization state, and controls the multi-layer meta-structure surface to phase-regulate the incident light based on the type, so as to realize dot matrix structured light projection or large-range beam projection, realize beam projection of different modes based on the type of the incident light, realize flexible switching between the two modes, overcome the flexibility limitation of the single-mode laser radar system in complex environments, increase the adaptability of the beam projection device in complex and changeable environments, and because of the use of multi-layer meta-structure surfaces, the meta-structure surface is small in size and light in weight, which can promote the laser radar technology to develop towards a higher level of integration and miniaturization. Thus, the problems that the laser radar in the related technology can only realize a single detection mode and has poor flexibility and adaptability are solved.
[0039] Specifically, Figure 1 A schematic diagram of a light beam projection device provided in an embodiment of the present application.
[0040] like Figure 1 As shown, the light beam projection device 10 includes: a device body 11, a light beam incident window 12, a multi-layer metasurface 13, a detection component 14 and a host computer 15.
[0041] Among them, the multilayer metasurface 13 is arranged in the device body 11 and behind the beam incident window 12, and is used to perform phase regulation on the incident light of the beam incident window 12 for at least one of dot matrix structured light projection and large-scale beam projection; the detection component 14 is arranged on the device body 11, and is used to detect the polarization state of the incident light; the host computer 15 is used to determine the type of the incident light based on the polarization state, and control the multilayer metasurface 13 to perform phase regulation on the incident light based on the type, so as to realize dot matrix structured light projection or large-scale beam projection.
[0042] It can be understood that the beam projection device 10 of the embodiment of the present application can detect the polarization state of the incident light through the detection component 14, and the upper computer 15 determines the type of the incident light based on the polarization state, and controls the multi-layer metasurface 13 to perform phase regulation on the incident light based on the type, so as to realize dot matrix structured light projection or large-scale beam projection, and realizes beam projection of different modes based on the type of incident light, and realizes flexible switching between the two modes, overcomes the flexibility limitation of the single-mode laser radar system in complex environments, and increases the adaptability of the beam projection device 10 in complex and changeable environments. In addition, due to the use of the multi-layer metasurface 13, the metasurface is small in size and light in weight, which can promote the development of laser radar technology towards a higher level of integration and miniaturization.
[0043] In the embodiment of the present application, the multi-layer metasurface 13 includes a primary metasurface and a secondary metasurface.
[0044] Among them, the first-level metasurface adopts geometric phase units and arrayed phase design, and the second-level metasurface adopts transmission phase units and non-arrayed phase design.
[0045] It can be understood that the embodiment of the present application adopts a hybrid cascade metasurface, that is, it includes a primary metasurface (level I metasurface) and a secondary metasurface (level II metasurface), and the primary metasurface and the secondary metasurface are composed of different types of units. The primary metasurface adopts a geometric phase unit and an arrayed phase design, which can achieve high-precision phase control of the incident light, and is particularly suitable for dot matrix structured light projection. The secondary metasurface adopts a transmission phase unit and a non-arrayed phase design, which is insensitive to the polarization state of the light wave and can achieve polarization-insensitive beamforming, which is suitable for large-range light beam projection. Through the cascading of the primary and secondary metasurfaces, the light beam projection device can flexibly switch between different projection modes to adapt to a variety of application scenarios.
[0046] In the embodiment of the present application, the geometric phase unit is composed of a plurality of rectangular nanocolumns with variable angles of the same size, and the phase is controlled by controlling the angle of each rectangular nanocolumn with variable angles.
[0047] It can be understood that the geometric phase unit in the embodiment of the present application is sensitive to the polarization state of the light wave, and can realize the mutual conversion of left-handed circularly polarized light and right-handed circularly polarized light, thereby realizing different projection modes, and through the careful design of the rotation angles of the rectangular nanocolumns, high-precision phase control of the incident light can be achieved, ensuring high precision and high resolution of the dot matrix structured light projection.
[0048] In the embodiment of the present application, the transmission phase unit is composed of variable diameter circular nanocolumns, and the phase is controlled by controlling the diameter of the variable diameter circular nanocolumns.
[0049] It can be understood that the transmission phase unit in the embodiment of the present application is insensitive to the polarization state of the light wave, and can realize polarization-insensitive beam forming, which is suitable for large-range light beam projection: by controlling the diameter of the circular nanocolumns, flexible phase control of the incident light can be achieved to ensure that the light beam has the desired shape and direction when it is emitted.
[0050] Specifically, the first-level metasurface Figure 2 As shown, the geometric phase unit and arrayed phase design are used. The unit structure is a rectangular nanocolumn with variable angles of the same size. Phase control is achieved by carefully designing the angles of the rectangular nanocolumns. The geometric metasurface is sensitive to the polarization of light waves, that is, left-handed circularly polarized light will be converted into right-handed circularly polarized light after passing through the geometric phase metasurface and given a geometric phase distribution, while right-handed circularly polarized light will be converted into left-handed circularly polarized light and given the opposite geometric phase distribution.
[0051] Secondary metasurfaces, such as Figure 3 As shown, a transmission phase unit and a non-arrayed phase design are adopted. The unit structure is a circular nanocolumn with a variable diameter. Phase control is achieved by carefully designing the diameter of the circular nanocolumn to realize polarization-insensitive beamforming.
[0052] In the embodiment of the present application, the host computer 15 is further used for: if the type of incident light is left-handed circularly polarized light, then controlling the first-level metasurface to focus the incident light into a lattice light beam, and controlling the second-level metasurface to adjust the exit deflection angle of the lattice light beam to achieve lattice structured light projection; if the type of incident light is right-handed circularly polarized light, then controlling the first-level metasurface to adjust the right-handed circularly polarized light to the opposite phase at the time of incidence, so that the right-handed circularly polarized light diverges, and controlling the second-level metasurface to emit the divergent right-handed circularly polarized light to achieve large-scale light beam projection.
[0053] It can be understood that, in the embodiment of the present application, when the type of incident light is left-handed circularly polarized light, the first-level metasurface is controlled to focus the incident light into a lattice light beam, and the second-level metasurface is controlled to adjust the exit deflection angle of the lattice light beam to achieve lattice structured light projection; when the type of incident light is right-handed circularly polarized light, the first-level metasurface is controlled to adjust the right-handed circularly polarized light to the opposite phase of the incident light, so that the right-handed circularly polarized light diverges, and the second-level metasurface is controlled to emit the divergent right-handed circularly polarized light to achieve large-scale light beam projection.
[0054] Specifically, when the incident light is left-handed circularly polarized light, Figure 4 As shown in the figure, the first-level metasurface first splits and focuses the incident light into a lattice beam, and then the second-level metasurface controls the outgoing deflection angle of the lattice beam to achieve lattice structured light projection with a large field of view and a small divergence angle; when the incident light is right-handed circularly polarized light, as shown in Figure 5 As shown, the first-level metasurface will give the opposite phase to the incident left-handed circularly polarized light, causing the incident light to diverge, and then be emitted through the second-level metasurface to achieve the same large-range beam illumination projection as the Flash lidar.
[0055] In the embodiment of the present application, the host computer 15 is further used to: if the type of the incident light is left-handed circularly polarized light, the phase distribution of the geometric phase unit in the first-level metasurface is:
[0056]
[0057] in, x is the coordinate of the x-axis, y is the coordinate of the y-axis, i, j is the i-th row and j-th column, p is a negative real constant, (Γj, Γi) is the coordinate of the center position of the array unit, n m ×P m is the aperture size of the first-level metasurface, n m is the array size, P m is the arraying period, is the phase distribution of the array unit in the i-th row and j-th column of the first-level metasurface at (x, y);
[0058] The phase distribution of the transmission phase unit in the secondary metasurface is:
[0059]
[0060] in, is the phase distribution of the secondary metasurface at (x, y);
[0061] If the type of incident light is right-handed circularly polarized light, the phase distribution of the geometric phase unit in the first-order metasurface is:
[0062]
[0063] in,
[0064] The phase distribution of the transmission phase unit in the secondary metasurface is the same as when the type of incident light is left-handed circularly polarized light.
[0065] Specifically, as a possible phase distribution design in the embodiment of the present application, the aperture size of the first-level metasurface is n m ×P m , where n m ×n m represents the array size, P m represents the array period. In the xy plane, the range occupied by the primary metasurface on the x-axis and y-axis is The range occupied by the array cell in the i-th row and j-th column on the x-axis is The range on the y-axis is The center position of the array unit is Γj, Γi = -nm2+j-12Pm, -nm2+i-12Pm, where i, j = 1, 2, ..., n m .
[0066] When the incident light is left-handed circularly polarized collimated light, the phase distribution of the metasurface array unit in the i-th row and column of the primary metasurface is:
[0067]
[0068] Where p is a negative real constant. According to this phase design, the incident light will be focused into n m ×n m Dot beam.
[0069] The phase distribution of the secondary metasurface is:
[0070]
[0071] When the distance between the primary metasurface and the secondary metasurface is ignored, the dot beam will project n m ×n m Large field of view, small divergence angle lattice structure beam, such as Figure 6 shown.
[0072] When the incident light is right-handed circularly polarized collimated light, the phase distribution of the metasurface array unit in the i-th row and column of the first-level metasurface is:
[0073]
[0074]
[0075] According to this phase design, the incident light will diverge after passing through the first-level metasurface. Since the second-level metasurface is polarization-insensitive, its phase distribution is still equation (2), so the final device will project a large-scale illumination beam, such as Figure 7 When the incident light is a pulsed laser, the beam projection effect consistent with that of the Flash LiDAR can be achieved.
[0076] In summary, the embodiments of the present application can utilize the polarization-sensitive characteristics of the geometric phase metasurface and the polarization-insensitive characteristics of the transmission metasurface, and realize flexible switching between the two laser radar detection modes of dot matrix structured light projection and large-scale beam projection by hybrid cascading the two, thereby overcoming the flexibility limitations of the single-mode laser radar system in complex environments and significantly enhancing the environmental adaptability and deployment flexibility of the system. For the needs of high-precision and long-distance environmental detection, the dot matrix structured light projection mode can be selected, and the scanning of the laser beam can be realized by translational control between cascaded metasurfaces. For application scenarios that require close-range and real-time environmental detection, the Flash large-scale beam projection mode can be selected to realize snapshot laser detection. In short, the present application makes full use of the multi-channel light wave control capability of the metasurface to realize dual-detection mode beam projection, and can also give play to the advantages of the metasurface being thin and easy to integrate, to realize a highly integrated and compact miniaturized laser radar, which is applied to human driving, intelligent robots, drone navigation and other fields.
[0077] According to the beam projection device proposed in the embodiment of the present application, the polarization state of the incident light can be detected by the detection component. The upper computer determines the type of the incident light based on the polarization state, and controls the multi-layer metasurface to perform phase regulation on the incident light based on the type, so as to realize dot matrix structured light projection or large-scale beam projection, and realizes beam projection of different modes based on the type of incident light, and realizes flexible switching between the two modes, which overcomes the flexibility limitations of a single-mode lidar system in a complex environment, increases the adaptability of the beam projection device in a complex and changeable environment, and because of the use of a multi-layer metasurface, the metasurface is small in size and light in weight, which can promote the development of lidar technology towards a higher level of integration and miniaturization.
[0078] Next, a control method of a light beam projection device according to an embodiment of the present application will be described with reference to the accompanying drawings.
[0079] Figure 8 It is a flow chart of the control method of the light beam projection device according to an embodiment of the present application.
[0080] like Figure 8 As shown, the control method of the light beam projection device includes the following steps:
[0081] In step S101 , the polarization state of incident light is acquired.
[0082] The polarization state of the incident light refers to the direction and mode in which the electric field vector of the light wave vibrates during propagation. A light wave is an electromagnetic wave whose electric field vector vibrates perpendicularly to the propagation direction.
[0083] In step S102 , the type of incident light is determined based on the polarization state.
[0084] The types of incident light include left-handed circularly polarized light and right-handed circularly polarized light.
[0085] Due to the polarization states of different incident lights, the electric field vectors of different circularly polarized lights vibrate along a spiral trajectory during propagation, and the radius of the spiral trajectory remains unchanged. For left-handed circularly polarized light, the electric field vector rotates counterclockwise, and for right-handed circularly polarized light, the electric field vector rotates clockwise. Therefore, the embodiment of the present application can determine the type of incident light based on the polarization state, so as to subsequently perform phase control based on the type of incident light.
[0086] In step S103, the phase of the incident light is controlled by the multi-layer metasurface based on the type to achieve dot matrix structured light projection or large-scale light beam projection.
[0087] The multi-layer metasurface includes a primary metasurface and a secondary metasurface.
[0088] It can be understood that the embodiments of the present application can control the phase of the incident light based on the type of the multi-layer metasurface to achieve dot matrix structured light projection or large-scale light beam projection, realize different modes of light beam projection based on the type of incident light, and realize flexible switching between the two modes, thereby overcoming the flexibility limitations of a single-mode lidar system in complex environments and increasing the adaptability of the light beam projection device in complex and changeable environments. The specific controls are as follows.
[0089] In an embodiment of the present application, a first-level multi-layer metasurface is controlled based on the type to perform phase control on the incident light, including: if the type of the incident light is left-handed circularly polarized light, the first-level metasurface is controlled to focus the incident light into a lattice light beam, and the second-level metasurface is controlled to control the exit deflection angle of the lattice light beam to achieve lattice structured light projection; if the type of the incident light is right-handed circularly polarized light, the first-level metasurface is controlled to control the right-handed circularly polarized light to have a phase opposite to that of the incident light, so that the right-handed circularly polarized light diverges, and the second-level metasurface is controlled to emit the divergent right-handed circularly polarized light to achieve wide-range light beam projection.
[0090] It can be understood that, in the embodiment of the present application, when the type of incident light is left-handed circularly polarized light, the first-level metasurface is controlled to focus the incident light into a lattice light beam, and the second-level metasurface is controlled to adjust the exit deflection angle of the lattice light beam to achieve lattice structured light projection; when the type of incident light is right-handed circularly polarized light, the first-level metasurface is controlled to adjust the right-handed circularly polarized light to the opposite phase of the incident light, so that the right-handed circularly polarized light diverges, and the second-level metasurface is controlled to emit the divergent right-handed circularly polarized light to achieve large-scale light beam projection.
[0091] It should be noted that the above explanation of the embodiment of the light beam projection device is also applicable to the control method of the light beam projection device of this embodiment, which will not be repeated here.
[0092] According to the control method of the light beam projection device proposed in the embodiment of the present application, the phase of the incident light can be controlled by controlling the multi-layer metasurface based on the type to realize dot matrix structured light projection or large-range light beam projection, and light beam projection of different modes based on the type of incident light is realized, and flexible switching between the two modes is realized, which overcomes the flexibility limitations of a single-mode lidar system in complex environments and increases the adaptability of the light beam projection device in complex and changing environments.
[0093] Fig. 9 A schematic diagram of the structure of the host computer provided in the embodiment of the present application. The host computer may include:
[0094] A memory 901 , a processor 902 , and a computer program stored in the memory 901 and executable on the processor 902 .
[0095] When the processor 902 executes the program, the control method of the light beam projection device provided in the above embodiment is implemented.
[0096] Furthermore, the host computer also includes:
[0097] The communication interface 903 is used for communication between the memory 901 and the processor 902 .
[0098] The memory 901 is used to store computer programs that can be executed on the processor 902 .
[0099] The memory 901 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.
[0100] If the memory 901, the processor 902 and the communication interface 903 are implemented independently, the communication interface 903, the memory 901 and the processor 902 can be connected to each other through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Fig. 9 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.
[0101] Optionally, in a specific implementation, if the memory 901, the processor 902 and the communication interface 903 are integrated on a chip, the memory 901, the processor 902 and the communication interface 903 can communicate with each other through an internal interface.
[0102] The processor 902 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.
[0103] An embodiment of the present application also provides a computer-readable storage medium on which a computer program or instruction is stored. When the computer program or instruction is executed by a processor, the control method of the light beam projection device as described above is implemented.
[0104] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.
[0105] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.
[0106] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.
[0107] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one or a combination of multiple of the following technologies known in the art: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.
[0108] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.
Claims
1. A light beam projection device, characterized in that: include: Device body and light beam incident window; A multi-layer metasurface disposed in the device body, wherein the multi-layer metasurface is disposed behind the light beam incident window and is used to perform phase control on at least one of lattice structured light projection and large-scale light beam projection on incident light from the light beam incident window; A detection component disposed on the device body, used to detect the polarization state of incident light; A host computer is used to determine the type of the incident light based on the polarization state, and control the multi-layer metasurface to perform phase regulation on the incident light based on the type, so as to realize the dot matrix structured light projection or the large-range light beam projection.
2. The light beam projection device according to claim 1, characterized in that: The multi-layer metasurface includes a primary metasurface and a secondary metasurface, wherein the primary metasurface adopts a geometric phase unit and an arrayed phase design, and the secondary metasurface adopts a transmission phase unit and a non-arrayed phase design.
3. The light beam projection device according to claim 2, characterized in that: The geometric phase unit is composed of a plurality of rectangular nanocolumns with variable angles of the same size, and the phase is controlled by controlling the angle of each rectangular nanocolumn with variable angles.
4. The light beam projection device according to claim 2, characterized in that: The transmission phase unit is composed of circular nanocolumns with variable diameters, and phase regulation is performed by controlling the diameter of the circular nanocolumns with variable diameters.
5. The light beam projection device according to claim 2, characterized in that: The host computer is further used for: If the type of the incident light is left-handed circularly polarized light, controlling the primary metasurface to focus the incident light into a lattice light beam, and controlling the secondary metasurface to adjust the exit deflection angle of the lattice light beam to achieve the lattice structured light projection; If the type of the incident light is right-handed circularly polarized light, the first-level metasurface is controlled to adjust the right-handed circularly polarized light to a phase opposite to that of the incident light, so that the right-handed circularly polarized light diverges, and the second-level metasurface is controlled to emit the divergent right-handed circularly polarized light to achieve the large-range light beam projection.
6. The light beam projection device according to claim 5, characterized in that: The host computer is further used for: If the type of the incident light is left-handed circularly polarized light, the phase distribution of the geometric phase unit in the primary metasurface is: in, x is the coordinate of the x-axis, y is the coordinate of the y-axis, i,j is the i-th row and j-th column, p is a negative real constant, (Γ j , Γ i ) is the center position coordinate of the array unit, n m ×P m is the aperture size of the first-level metasurface, n m is the array size, P m is the arraying period, is the phase distribution of the array unit in the i-th row and j-th column of the first-level metasurface at (x, y); The phase distribution of the transmission phase unit in the secondary metasurface is: in, is the phase distribution of the secondary metasurface at (x, y); If the type of the incident light is right-handed circularly polarized light, the phase distribution of the geometric phase unit in the metasurface is: in, The phase distribution of the transmission phase unit in the secondary metasurface is the same as when the type of incident light is left-handed circularly polarized light.
7. A method for controlling a light beam projection device, characterized in that: Used to control the light beam projection device according to any one of claims 1 to 6, comprising the following steps: Obtaining the polarization state of incident light; determining a type of the incident light based on the polarization state; Based on the type described, multi-layer metasurfaces are controlled to perform phase regulation to achieve dot matrix structured light projection or large-range light beam projection.
8. The control method of the light beam projection device according to claim 7, characterized in that: The multi-layer metasurface includes a primary metasurface and a secondary metasurface, and the phase control of the primary multi-layer metasurface based on the type includes: If the type of the incident light is left-handed circularly polarized light, controlling the primary metasurface to focus the incident light into a lattice light beam, and controlling the secondary metasurface to adjust the exit deflection angle of the lattice light beam to achieve the lattice structured light projection; If the type of the incident light is right-handed circularly polarized light, the first-level metasurface is controlled to adjust the right-handed circularly polarized light to a phase opposite to that of the incident light, so that the right-handed circularly polarized light diverges, and the second-level metasurface is controlled to emit the divergent right-handed circularly polarized light to achieve the large-range light beam projection.
9. A host computer, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the control method of the light beam projection device as claimed in claim 7 or 8.
10. A computer-readable storage medium having a computer program or instruction stored thereon, characterized in that: The computer program or instructions are executed by a processor to implement the control method of the light beam projection device as claimed in claim 7 or 8.