A laser radar system

Abstract

The present invention provides a laser radar system, wherein the laser radar system includes: a polarization detection system, a transmitting device, a signal filtering device, and a receiving device; the transmitting device is used to transmit a first light beam into the air; the polarization detection system is used to detect polarization light characteristics corresponding to target polarization light, and the target polarization light represents light scattered by the air; the signal filtering device is arranged on the light incident side of the receiving device, and the signal filtering device can filter the current polarization light of the first light beam scattered by the air based on the polarization light characteristics detected by the polarization detection system, and project the filtered first light beam to the receiving device; the current polarization light represents polarization light corresponding to the polarization light characteristics. The laser radar system provided by the embodiment of the present invention has low computational complexity, fast processing speed, high accuracy, and its cost is also lower than that of laser radar systems using image processing methods, which is more in line with market demand.

Description

Technical Field

[0001] The present invention relates to the field of laser radar technology, and in particular to a laser radar system. Background Art

[0002] LiDAR (LiDAR) has shown great market potential in numerous applications, including intelligent robots, fully autonomous driving, and drones. However, in inclement weather (such as smog) or harsh environments (such as fire scenes), LiDAR's echo signals, affected by scattering from airborne particles, can generate significant noise or erroneous signals. This can easily lead to increased bit error rates and incorrect reconstruction of environmental location information, thus degrading LiDAR performance.

[0003] Existing LiDAR systems primarily use image processing methods (such as Kalman filtering or convolutional neural networks) to algorithmically determine the scattered signals of particles in the environment, thereby eliminating their influence and achieving defogging. However, image processing methods are computationally complex, slow, and expensive. As LiDAR systems have advanced, these image processing-integrated LiDARs have struggled to meet market demand. Summary of the Invention

[0004] To solve the above problems, an embodiment of the present invention aims to provide a laser radar system.

[0005] An embodiment of the present invention provides a laser radar system, including: a polarization detection system, a transmitting device, a signal filtering device and a receiving device; the transmitting device is used to transmit a first light beam into the air; the polarization detection system is used to detect polarization light characteristics corresponding to the target polarization light, and the target polarization light represents light scattered by the air; the signal filtering device is arranged on the light incident side of the receiving device, and the signal filtering device can filter the current polarization light of the first light beam scattered by the air based on the polarization light characteristics detected by the polarization detection system, and project the filtered first light beam to the receiving device; the current polarization light represents polarization light corresponding to the polarization light characteristics.

[0006] Optionally, the polarization detection system includes: a light source module, a collecting device and a polarization detection device; the collecting device is arranged on the light output side of the light source module, and the polarization detection device is arranged on the side of the collecting device away from the light source module; the collecting device is used to collect the air; the light source module is used to emit a second light beam to the collecting device; the second light beam is scattered into target polarized light by the air in the collecting device and is emitted to the polarization detection device; the polarization detection device is used to detect the polarization light characteristics corresponding to the target polarized light, and the polarization light characteristics represent the light intensity corresponding to different polarization states of the target polarized light.

[0007] Optionally, the polarization detection device includes: a polarization detection metasurface and a pixel unit; the polarization detection metasurface is used to disperse the target polarized light into multiple sub-beams, each of the sub-beams corresponding to a polarization state of the target polarized light; the pixel unit is arranged on the light-emitting side of the polarization detection metasurface, for receiving the multiple sub-beams and determining the light intensity of each sub-beam.

[0008] Optionally, the polarization detection metasurface includes: a first metasurface and a second metasurface; the pixel unit includes: a first pixel, a second pixel, a third pixel and a fourth pixel; the first metasurface is used to modulate the target polarized light into a sub-beam corresponding to the polarization state in the x-direction and a sub-beam corresponding to the polarization state in the y-direction, and respectively emit the two sub-beams to the first pixel and the second pixel; the second metasurface is used to modulate the target polarized light into a sub-beam corresponding to the polarization state in the positive 45-degree direction and a sub-beam corresponding to the polarization state in the negative 45-degree direction, and respectively emit the two sub-beams to the third pixel and the fourth pixel.

[0009] Optionally, the polarization detection metasurface further includes: a third metasurface; the pixel unit further includes: a fifth pixel and a sixth pixel; the third metasurface is used to modulate the target polarized light into a sub-beam corresponding to the polarization state of left-handed light and a sub-beam corresponding to the polarization state of right-handed light, and respectively emit the two sub-beams to the fifth pixel and the sixth pixel.

[0010] Optionally, the operating band of the polarization detection metasurface is the near-infrared band.

[0011] Optionally, the polarization detection device includes: a polarization camera.

[0012] Optionally, the light source module includes a first light source; the first light source includes a fiber laser, an edge-emitting laser array, a vertical cavity surface-emitting laser array or a light-emitting diode.

[0013] Optionally, the light source module includes: a mechanical rotating device and a second light source fixedly arranged on the mechanical rotating device.

[0014] Optionally, the light source module includes: a third light source and a deflection angle rotation device arranged on the light emitting side of the third light source.

[0015] Optionally, the filter in the signal filtering device includes: a polarizer, a combination of a polarizer and a quarter wave plate, a metasurface polarizer, or a multifunctional metasurface capable of filtering polarized light.

[0016] Optionally, the lidar system also includes: a processing device; the processing device is respectively connected to the polarization detection system and the signal filtering device, and is used to instruct the signal filtering device to filter the current polarized light of the first light beam scattered by the air according to the polarization light characteristics detected by the polarization detection system.

[0017] Optionally, the first light beam emitted by the emitting device is the same as the second light beam in the polarization detection system.

[0018] In the solution provided above in the embodiment of the present invention, when it is necessary to remove echo signal errors caused by the scattering of haze particles in the air, unlike traditional image processing methods, a polarization detection system is provided in the laser radar system. This polarization detection system detects the polarization characteristics of light scattered by the air, allowing the signal filtering device in the laser radar system to filter the current polarized light with this polarization characteristic that is incident thereon, thereby enabling the receiving device to receive a more accurate echo signal. This laser radar system has low computational complexity, fast processing speed, high accuracy, and is also less expensive than laser radar systems using image processing methods, better meeting market demand.

[0019] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 A schematic diagram of a laser radar system provided by an embodiment of the present invention is shown;

[0022] Figure 2 A schematic diagram of a polarization detection system in a laser radar system provided by an embodiment of the present invention is shown;

[0023] Figure 3 A schematic diagram of a polarization detection device in a laser radar system provided by an embodiment of the present invention is shown;

[0024] Figure 4 A schematic diagram of a polarization detection device including a first metasurface and a second metasurface in a laser radar system provided by an embodiment of the present invention is shown;

[0025] Figure 5A schematic diagram of a polarization detection device including a first metasurface, a second metasurface, and a third metasurface in a laser radar system provided by an embodiment of the present invention is shown;

[0026] Figure 6 A schematic diagram of a first light source module in a laser radar system provided by an embodiment of the present invention is shown;

[0027] Figure 7 FIG2 shows a schematic diagram of a second light source module in a laser radar system provided by an embodiment of the present invention;

[0028] Figure 8 FIG2 shows a schematic diagram of a third light source module in a laser radar system provided by an embodiment of the present invention;

[0029] Figure 9 A schematic diagram of a processing device in a laser radar system provided by an embodiment of the present invention is shown.

[0030] icon:

[0031] 1-Polarization detection system, 2-Transmitting device, 3-Signal filtering device, 4-Receiving device, 5-Processing device, 11-Light source module, 12-Collecting device, 13-Polarization detection device, 131-Polarization detection metasurface, 132-Pixel unit, 131a-First metasurface, 131b-Second metasurface, 131c-Third metasurface, 132a-First pixel, 132b-Second pixel, 132c-Third pixel, 132d-Fourth pixel, 132e-Fifth pixel, 132f-Sixth pixel, 111-First light source, 112-Mechanical rotation device, 113-Second light source, 114-Third light source, 115-Deflection angle rotation device. DETAILED DESCRIPTION

[0032] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0034] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0035] The embodiment of the present invention provides a laser radar system, see Figure 1 As shown, the laser radar system includes: a polarization detection system 1, a transmitting device 2, a signal filtering device 3 and a receiving device 4; the transmitting device 2 is used to transmit a first light beam into the air; the polarization detection system 1 is used to detect the polarization light characteristics corresponding to the target polarization light, and the target polarization light represents the light scattered by the air; the signal filtering device 3 is arranged on the light incident side of the receiving device 4, and the signal filtering device 3 can filter the current polarization light of the first light beam scattered by the air based on the polarization light characteristics detected by the polarization detection system 1, and project the filtered first light beam to the receiving device 4; the current polarization light represents the polarization light corresponding to the polarization light characteristics.

[0036] like Figure 1 As shown, Figure 1 The air is represented by the smoke pattern located above; the polarization detection system 1 in the laser radar system can detect the polarization light characteristics corresponding to the target polarization light, wherein the polarization light characteristics corresponding to the target polarization light refer to: the characteristics of the polarized light scattered by particles suspended in the air (such as haze particles or dust particles at a fire scene, etc.). The transmitting device 2 in the laser radar system is used to transmit a first light beam to the air, and the first light beam may include partially polarized light or natural light; when the first light beam enters the air, the air (such as particles in the air) can scatter the first light beam to obtain a scattered first light beam, and the scattered first light beam can be emitted to the signal filtering device 3 in the laser radar system. The scattered first light beam is a first light beam including the current polarization light, and the current polarization light is polarized light scattered by the air, which corresponds to the polarization light characteristics.

[0037] In an embodiment of the present invention, the signal filtering device 3 filters the currently polarized light in the scattered first light beam entering the signal filtering device 3 based on the polarization characteristics of the air detected by the polarization detection system 1, and transmits the filtered first light beam to a receiving device 4 located on the light-exiting side of the signal filtering device 3. Optionally, the signal filtering device 3 includes a filter, which includes one of: an analyzer, a combination of an analyzer and a quarter-wave plate, a metasurface polarizer, or a multifunctional metasurface capable of filtering polarized light. The filter is an optical device used to allow or block the transmission of light within a certain wavelength range, thereby detecting various polarizations. Selecting a polarizer, or a combination of an analyzer and a quarter-wave plate, as the filter in the signal filtering device 3 can reduce the overall manufacturing cost of the laser radar system. Selecting a metasurface polarizer or a multifunctional metasurface capable of filtering polarized light as the filter in the signal filtering device 3 can make the overall structure of the laser radar system more compact and lightweight, making it more suitable for relatively small installation spaces.

[0038] The lidar system provided in an embodiment of the present invention, when it is necessary to remove echo signal errors caused by the scattering of haze particles in the air, differs from traditional image processing methods in that a polarization detection system 1 is provided in the lidar system. This polarization detection system 1 detects the polarization characteristics corresponding to the light scattered by the air, enabling the signal filtering device 3 in the lidar system to filter the current polarized light with this polarization characteristic incident thereon, thereby enabling the receiving device 4 to receive a more accurate echo signal. This lidar system has low computational complexity, fast processing speed, high accuracy, and is also less expensive than lidar systems using image processing methods, better meeting market demand.

[0039] Alternatively, see Figure 2 As shown, the polarization detection system 1 includes: a light source module 11, a collection device 12 and a polarization detection device 13; the collection device 12 is arranged on the light output side of the light source module 11, and the polarization detection device 13 is arranged on the side of the collection device 12 away from the light source module 11; Figure 2 In the figure, the right side of the light source module 11 is shown as the light emitting side of the light source module 11 .

[0040] Among them, the collecting device 12 is used to collect air; the light source module 11 is used to emit a second light beam to the collecting device 12; the second light beam is scattered into target polarized light by the air in the collecting device 12 and is emitted to the polarization detection device 13; the polarization detection device 13 is used to detect the polarization light characteristics corresponding to the target polarized light, and the polarization light characteristics represent the light intensity corresponding to different polarization states of the target polarized light.

[0041] In the laser radar system provided in an embodiment of the present invention, the collecting device 12 included in the polarization detection system 1 is a container that can be connected to the air to accommodate the air entering it; the light source module 11 is used to emit a second light beam to the collecting device 12, and the second light beam may include partially polarized light or natural light; when the second light beam enters the collecting device 12, the air concentrated in the collecting device 12 can scatter the second light beam to obtain a scattered second light beam; wherein, the scattered second light beam includes target polarized light (i.e., polarized light whose polarization characteristics need to be detected), and the target polarized light can be emitted to the polarization detection device 13 arranged on the light output side of the collecting device 12.

[0042] In an embodiment of the present invention, the polarization detection device 13 can detect characteristics of the target polarized light incident thereon. The characteristics of the target polarized light are the polarization characteristics corresponding to the light scattered by the air. Since the target polarized light can be modulated into a variety of different polarization states (such as an x-direction polarization state or a y-direction polarization state), and each polarization state corresponds to a different light intensity, the light intensities corresponding to the different polarization states that can be modulated in the target polarized light can be used as the characteristics of the target polarized light, i.e., the polarization characteristics corresponding to the light scattered by the air. For example, the polarization characteristics can include the light intensity corresponding to the target polarized light modulated into the x-direction polarization state, and the polarization characteristics can include the light intensity corresponding to the target polarized light modulated into the y-direction polarization state, etc. Optionally, the polarization detection device 13 includes a polarization camera. The polarization camera can directly obtain the light intensities corresponding to the different polarization states of the target polarized light, such as Stokes parameters, i.e., the polarization state characteristics corresponding to the target polarized light. The polarization camera can be a full-Stokes camera.

[0043] In the lidar system provided by the embodiments of the present invention, the polarization detection system 1 has a simple overall structure. It determines the polarization characteristics of the target polarized light simply by measuring the intensity of the different polarization states of the target polarized light scattered by the air. This detection process eliminates the need for extensive calculations, resulting in rapid detection. Furthermore, the polarization detection system 1 can detect the polarization characteristics of the light scattered by the air in real time at a relatively low frequency, significantly reducing detection costs.

[0044] Alternatively, see Figure 3 As shown, the polarization detection device 13 includes: a polarization detection metasurface 131 and a pixel unit 132; the polarization detection metasurface 131 is used to disperse the target polarized light into multiple sub-beams, each sub-beam corresponding to a polarization state in the target polarized light; the pixel unit 132 is arranged on the light-emitting side of the polarization detection metasurface 131, and is used to receive multiple sub-beams and determine the light intensity of each sub-beam.

[0045] The polarization detection metasurface 131 is arranged on a side of the polarization detection device 13 close to the collecting device 12, as shown in FIG. Figure 3 On the left side of the polarization detection device 13, the target polarized light passing through the collecting device 12 and incident on the polarization detection device 13 can directly enter the polarization detection metasurface 131. In an embodiment of the present invention, the target polarized light can be dispersed into multiple sub-beams after being modulated by the polarization detection metasurface 131, and each sub-beam corresponds to a polarization state that the target polarized light can be modulated to. For example, the target polarized light incident on the polarization detection metasurface 131 through the collecting device 12 can be dispersed into two sub-beams after being modulated by the polarization detection metasurface 131, one sub-beam can correspond to the polarization state in the x-direction, and the other sub-beam can correspond to the polarization state in the y-direction. Optionally, the operating band of the polarization detection metasurface 131 is the near-infrared band, that is, the operating band of the second light beam is the near-infrared band, for example, it has high transmittance for light in the near-infrared band. Among them, near-infrared light is an electromagnetic wave between visible light and mid-infrared light, and is defined by the American Society for Testing and Materials as an electromagnetic wave with a wavelength in the range of 780 to 2526 nm. For example, the operating wavelength band of the polarization detection metasurface 131 in the embodiment of the present invention can be 885nm~925nm, or 1520nm~1570nm.

[0046] In the embodiment of the present invention, the pixel unit 132 is arranged on the light-emitting side of the polarization detection metasurface 131 (e.g. Figure 3 The pixel unit 132 is located on the right side of the polarization detection metasurface 131 in the image sensor 130, and can receive multiple sub-beams dispersed by the polarization detection metasurface 131, and can determine the corresponding light intensity for each sub-beam. For example, the pixel unit 132 can determine the light intensity corresponding to the sub-beam of polarization state in the x direction and the sub-beam of polarization state in the y direction dispersed by the polarization detection metasurface 131 (such as the light intensity of the sub-beam of polarization state in the x direction and the light intensity of the sub-beam of polarization state in the y direction). The light intensity corresponding to the sub-beams of different polarization states can be expressed as the characteristics of the target polarization state, such as the polarization light characteristics corresponding to the light scattered by the air.

[0047] In the laser radar system provided by the embodiment of the present invention, its polarization detection device 13 adopts a polarization detection metasurface 131 as an optical device for dispersing target polarized light. It can not only accurately modulate the target polarized light so that the multiple sub-beams obtained by dispersion are sub-beams with different polarization states; it can also enable the laser radar system with the polarization detection metasurface 131 to have the advantages of light weight, thin overall thickness, simple system, lower price and high production capacity.

[0048] Alternatively, see Figure 4As shown, the polarization detection metasurface 131 includes: a first metasurface 131a and a second metasurface 131b; the pixel unit 132 includes: a first pixel 132a, a second pixel 132b, a third pixel 132c and a fourth pixel 132d; the first metasurface 131a is used to modulate the target polarized light into a sub-beam corresponding to the polarization state in the x-direction and a sub-beam corresponding to the polarization state in the y-direction, and respectively direct the two sub-beams to the first pixel 132a and the second pixel 132b; the second metasurface 131b is used to modulate the target polarized light into a sub-beam corresponding to the polarization state in the positive 45-degree direction and a sub-beam corresponding to the polarization state in the negative 45-degree direction, and respectively direct the two sub-beams to the third pixel 132c and the fourth pixel 132d.

[0049] In the embodiment of the present invention, the polarization detection metasurface 131 in the polarization detection device 13 may include a first metasurface 131a and a second metasurface 131b; Figure 4 As shown, the first metasurface 131a can modulate the target polarized light into a beam with a polarization state in the x-direction and a polarization state in the y-direction (such as a pair of sub-beams polarized in orthogonal directions), and the second metasurface 131b can modulate the target polarized light into a beam with a polarization state in the positive 45-degree direction and a polarization state in the negative 45-degree (i.e., 135-degree) direction, so that the polarization detection device 13 used in the embodiment of the present invention is a device capable of detecting linear polarized light.

[0050] like Figure 4As shown, the pixel unit 132 in the polarization detection device 13 may also include multiple pixels, which may include a first pixel 132a, a second pixel 132b, a third pixel 132c and a fourth pixel 132d; wherein, a metasurface can correspond to two pixels one-to-one, and the pixels corresponding to each metasurface are different, so as to realize that the sub-beams of two different polarization states dispersed by the metasurface are respectively emitted to the two pixels corresponding to the metasurface; for example, the first metasurface 131a can correspond to the first pixel 132a and the second pixel 132b, and the sub-beam corresponding to the polarization state in the x direction dispersed by the first metasurface 131a can be emitted to the first pixel 132a, so that the first pixel 132a can process the sub-beam corresponding to the polarization state in the x direction; and the sub-beam corresponding to the polarization state in the y direction dispersed by the first metasurface 131a can be emitted to the second pixel 132b, so that the second pixel 132b can process the sub-beam corresponding to the polarization state in the y direction. Similarly, the second metasurface 131b can correspond to the third pixel 132c and the fourth pixel 132d. The sub-beam corresponding to the polarization state in the positive 45-degree direction dispersed by the second metasurface 131b can be emitted to the third pixel 132c, so that the third pixel 132c can process the sub-beam corresponding to the polarization state in the positive 45-degree direction; and the sub-beam corresponding to the polarization state in the negative 45-degree direction dispersed by the second metasurface 131b can be emitted to the fourth pixel 132d, so that the fourth pixel 132d can process the sub-beam corresponding to the polarization state in the negative 45-degree direction.

[0051] When the first pixel 132a, the second pixel 132b, the third pixel 132c, and the fourth pixel 132d each receive a sub-beam corresponding to a corresponding polarization state, the light intensity of each received sub-beam can be determined. For example, the target polarized light is decomposed into the light intensities corresponding to the corresponding polarization states, so that the polarization state characteristics corresponding to the light scattered by the air can be determined. In this embodiment of the present invention, the x-direction and the y-direction are two directions perpendicular to each other. For example, the x-direction can be the horizontal direction and the y-direction can be the vertical direction. The positive 45-degree direction is a direction with a positive 45-degree angle with the x-direction, and the negative 45-degree direction is a direction with a negative 45-degree angle with the x-direction.

[0052] The polarization detection metasurface 131 adopted in the embodiment of the present invention includes two metasurfaces, namely, a first metasurface 131a and a second metasurface 131b, which can decompose the target polarized light into sub-beams in the x-direction and the y-direction, and decompose the target polarized light into sub-beams in the positive 45-degree direction and the negative 45-degree direction, and each metasurface is provided with a first pixel 132a, a second pixel 132b, a third pixel 132c and a fourth pixel 132d for receiving sub-beams in different polarization states, respectively; so that the laser radar system including this structure can detect the light intensity of multiple linear polarizations in the target polarized light.

[0053] Alternatively, see Figure 5 As shown, the polarization detection metasurface 131 also includes: a third metasurface 131c; the pixel unit 132 also includes: a fifth pixel 132e and a sixth pixel 132f; the third metasurface 131c is used to modulate the target polarized light into a sub-beam corresponding to the polarization state of left-handed light and a sub-beam corresponding to the polarization state of right-handed light, and respectively emit the two sub-beams to the fifth pixel 132e and the sixth pixel 132f.

[0054] In the embodiment of the present invention, the polarization detection metasurface 131 in the polarization detection device 13 includes, in addition to the first metasurface 131a and the second metasurface 131b, a third metasurface 131c; Figure 5 As shown, the third metasurface 131c can modulate the target polarized light into the polarization state of left-handed light and the polarization state of right-handed light, so that the polarization detection device 13 used in the embodiment of the present invention can detect not only linear polarization light but also circular polarization light.

[0055] like Figure 5As shown, the pixel unit 132 in the polarization detection device 13 may further include a fifth pixel 132e and a sixth pixel 132f in addition to the first pixel 132a, the second pixel 132b, the third pixel 132c and the fourth pixel 132d; and the correspondence between the fifth pixel 132e and the sixth pixel 132f and the third metasurface 131c is consistent with the correspondence between the other two metasurfaces and the pixels, that is, the third metasurface 131c may correspond to the fifth pixel 132e and the sixth pixel 132f, so as to realize the dispersion of the third metasurface 131c. The two sub-beams of different polarization states are respectively emitted to the fifth pixel 132e and the sixth pixel 132f corresponding to the third metasurface 131c; for example, the sub-beam corresponding to the polarization state of the left-handed light dispersed by the third metasurface 131c can be emitted to the fifth pixel 132e, so that the fifth pixel 132e can process the sub-beam corresponding to the polarization state of the left-handed light; and the sub-beam corresponding to the polarization state of the right-handed light dispersed by the third metasurface 131c can be emitted to the sixth pixel 132f, so that the sixth pixel 132f can process the sub-beam corresponding to the polarization state of the right-handed light.

[0056] In the case that the fifth pixel 132e and the sixth pixel 132f also receive sub-beams corresponding to corresponding polarization states, it can be determined that the target polarized light is decomposed into light intensities corresponding to corresponding polarization states.

[0057] The embodiment of the present invention adds a third metasurface 131c and a fifth pixel 132e and a sixth pixel 132f corresponding to the third metasurface 131c on the basis of only two metasurfaces. It can not only detect linear polarization in the target polarized light, but also detect circular polarization, with a larger detection range, so that the lidar system can better eliminate the influence of light scattered by the air on the echo signal.

[0058] Alternatively, see Figure 6 As shown, the light source module 11 includes a first light source 111 ; the first light source 111 includes a fiber laser, an edge-emitting laser array, a vertical cavity surface-emitting laser array or a light-emitting diode.

[0059] Among them, when the light source module 11 includes a first light source 111, in order to make the second light beam emitted by the light source module 11 satisfy partially polarized light or natural light, the first light source 111 can include a fiber laser, an edge-emitting laser array, a vertical cavity surface emitting laser array or a light-emitting diode with poor polarization (such as the second light beam emitted by the first light source 111 can be decomposed into sub-beams corresponding to more types of polarization states) to achieve a richer variety of polarization states of the second light beam.

[0060] Alternatively, see Figure 7As shown, the light source module 11 includes: a mechanical rotating device 112 and a second light source 113 fixedly mounted on the mechanical rotating device 112. The mechanical rotating device 112 can rotate in a clockwise or counterclockwise direction, and drive the second light source 113 mounted on the upper surface of the mechanical rotating device 112 to rotate in the same direction; and the second light source 113 can be a fiber laser, edge-emitting laser array, vertical cavity surface-emitting laser array or light-emitting diode with any polarization, which is not limited in the embodiment of the present invention. Figure 7 As shown, the mechanical rotating device 112 can rotate in the direction of the arrow, so that the second light source 113 can also rotate in the direction of the arrow while emitting the second light beam. Figure 7 Such a structural arrangement allows for a richer variety of polarization states of the second light beam ultimately emitted by the light source module 11, based on the rotation function of the mechanical rotating device 112, even when the second light source 113 is a light source with a strong polarization property, for example, the second light beam emitted by the second light source 113 can only be decomposed into sub-beams with a polarization state in the x-direction.

[0061] Alternatively, see Figure 8 As shown, the light source module 11 includes: a third light source 114 and a deflection angle rotation device 115 provided on the light-emitting side of the third light source 114. The deflection angle rotation device 115 can be a self-rotating device provided on the light-emitting side of the third light source 114. For example, the deflection angle rotation device 115 can rotate in a clockwise or counterclockwise direction. Figure 8 The deflection angle rotation device 115 can rotate in the direction of the arrow; the third light source 114 can be a fiber laser, edge-emitting laser array, vertical-cavity surface-emitting laser array, or light-emitting diode of any polarization. In this embodiment of the present invention, after the second light beam emitted by the third light source 114 passes through the deflection angle rotation device 115 and is emitted, the second light beam can be decomposed into a wider variety of polarization states.

[0062] Alternatively, see Figure 9 As shown, the laser radar system also includes: a processing device 5; the processing device 5 is connected to the polarization detection system 1 and the signal filtering device 3 respectively, and is used to instruct the signal filtering device 3 to filter the current polarized light scattered by the air of the first light beam according to the polarization light characteristics detected by the polarization detection system 1.

[0063] In the laser radar system provided in an embodiment of the present invention, a processing device 5 can be set between the polarization detection system 1 and the signal filtering device 3. The processing device 5 is capable of processing the polarization light characteristics detected by the polarization detection system 1, calculating the angle of the current polarized light that needs to be filtered by the signal filtering device 3, and controlling the rotation of the filter in the signal filtering device 3 to achieve the function of filtering the current polarized light.

[0064] Specifically, when the polarization detection device 13 includes the first metasurface 131a and the second metasurface 131b, and the first pixel 132a, the second pixel 132b, the third pixel 132c, and the fourth pixel 132d respectively determine the light intensities corresponding to different polarization states of the target polarized light, the formula The three Stokes parameters S0, S1 and S2 corresponding to the target polarized light are calculated; where I represents the total light intensity of all polarization states corresponding to the target polarized light; I x I represents the light intensity corresponding to the sub-beams of polarization state in the x direction after the target polarized light is decomposed; y I represents the light intensity corresponding to the sub-beams of polarization state in the y direction after the target polarized light is decomposed; 45 Indicates the intensity of the target polarized light when it is decomposed into sub-beams with a polarization state of positive 45 degrees; I -45 Indicates that the target polarized light is decomposed into the intensity of the sub-beams with a polarization state of minus 45 degrees; after determining the Stokes parameter, we can continue to use the formula Determine the light intensity I(α) of the target polarized light in any polarization direction α. Similarly, when the polarization detection device 13 further includes a third metasurface 131c, and each pixel determines the light intensity corresponding to different polarization states of the target polarized light, the formula The four Stokes parameters S0, S1, S2 and S3 corresponding to the target polarization light are calculated; R Indicates the intensity of the target polarized light decomposed into right-handed polarization sub-beams; I L Indicates the intensity of the target polarized light decomposed into the sub-beams of the left-handed polarization state; I, I x , I y , I 45 and I -45 The meaning of only including the first metasurface 131a and the second metasurface 131b is the same and will not be repeated here. After determining the four Stokes parameters, the embodiment of the present invention can continue to use the formula Determine the light intensity I(α) of the target polarized light in any polarization direction α.

[0065] Optionally, the first light beam emitted by the emitting device 2 is the same as the second light beam in the polarization detection system 1 .

[0066] In the laser radar system provided by an embodiment of the present invention, if the first light beam emitted by the transmitting device 2 is made identical to the second light beam in the polarization detection system 1, the accuracy of the polarization light characteristics corresponding to the light scattered by the air detected can be improved. The transmitting device 2 and the light source module 11 in the polarization detection system 1 can be two devices of the same structure, and the first light beam or the second light beam generated by each can be exactly the same; alternatively, in the laser radar system, only the transmitting device 2 (or the light source module 11 in the polarization detection system 1) can be provided, and a spectrometer can be used to split the first light beam (or the second light beam) emitted by the transmitting device 2 (or the light source module 11 in the polarization detection system 1) into the light source module 11 (or the transmitting device 2) in the polarization detection system 1, so that the first light beam and the second light beam are identical.

[0067] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technical solution that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A laser radar system, characterized in that: include: Polarization detection system (1), transmitting device (2), signal filtering device (3), receiving device (4) and processing device (5); The emitting device (2) is used to emit a first light beam into the air; The polarization detection system (1) is used to detect the light intensity of different polarization states of target polarized light scattered by air, and determine the polarization light characteristics corresponding to the target polarized light, wherein the target polarized light represents the light scattered by air; The signal filtering device (3) is arranged on the light incident side of the receiving device (4), and the signal filtering device (3) is capable of filtering the current polarized light of the first light beam scattered by air based on the polarized light characteristics detected by the polarization detection system (1), and projecting the filtered first light beam to the receiving device (4); the current polarized light represents polarized light corresponding to the polarized light characteristics; The processing device (5) is arranged between the polarization detection system (1) and the signal filtering device (3), and the processing device (5) includes a filter; the processing device (5) determines the angle of the current polarized light that the signal filtering device (3) needs to filter based on the polarization light characteristics detected by the polarization detection system (1), and controls the filter to rotate so as to filter the current polarized light.

2. The laser radar system according to claim 1, characterized in that The polarization detection system (1) comprises: a light source module (11), a collecting device (12), and a polarization detection device (13); the collecting device (12) is arranged on the light-emitting side of the light source module (11), and the polarization detection device (13) is arranged on a side of the collecting device (12) away from the light source module (11); The collecting device (12) is used to collect air; the light source module (11) is used to emit a second light beam toward the collecting device (12); The second light beam is scattered by the air in the collecting device (12) into target polarized light and emitted to the polarization detection device (13); the polarization detection device (13) is used to detect polarization light characteristics corresponding to the target polarized light, and the polarization light characteristics represent the light intensity corresponding to different polarization states of the target polarized light.

3. The laser radar system according to claim 2, characterized in that The polarization detection device (13) comprises: a polarization detection metasurface (131) and a pixel unit (132); the polarization detection metasurface (131) is used to disperse the target polarized light into a plurality of sub-beams, each of the sub-beams corresponding to a polarization state of the target polarized light; The pixel unit (132) is arranged on the light-emitting side of the polarization detection metasurface (131) and is used to receive the plurality of sub-beams and determine the light intensity of each sub-beam.

4. The laser radar system according to claim 3, characterized in that The polarization detection metasurface (131) includes: a first metasurface (131a) and a second metasurface (131b); the pixel unit (132) includes: a first pixel (132a), a second pixel (132b), a third pixel (132c) and a fourth pixel (132d); The first metasurface (131a) is used to modulate the target polarized light into a sub-beam corresponding to a polarization state in the x-direction and a sub-beam corresponding to a polarization state in the y-direction, and respectively direct the two sub-beams toward the first pixel (132a) and the second pixel (132b); The second metasurface (131b) is used to modulate the target polarized light into a sub-beam corresponding to a polarization state in a positive 45-degree direction and a sub-beam corresponding to a polarization state in a negative 45-degree direction, and respectively direct the two sub-beams toward the third pixel (132c) and the fourth pixel (132d).

5. The laser radar system according to claim 4, characterized in that The polarization detection metasurface (131) further includes: a third metasurface (131c); the pixel unit (132) further includes: a fifth pixel (132e) and a sixth pixel (132f); The third metasurface (131c) is used to modulate the target polarized light into a sub-beam corresponding to the polarization state of left-handed light and a sub-beam corresponding to the polarization state of right-handed light, and respectively emit the two sub-beams to the fifth pixel (132e) and the sixth pixel (132f).

6. The laser radar system according to any one of claims 3 to 5, characterized in that: The operating band of the polarization detection metasurface (131) is the near-infrared band.

7. The laser radar system according to claim 2, characterized in that The polarization detection device (13) includes: a polarization camera.

8. The laser radar system according to claim 2, characterized in that The light source module (11) comprises a first light source (111); the first light source (111) comprises a fiber laser, an edge-emitting laser array, a vertical cavity surface-emitting laser array, or a light-emitting diode.

9. The laser radar system according to claim 2, characterized in that The light source module (11) comprises a mechanical rotating device (112) and a second light source (113) fixedly arranged on the mechanical rotating device (112).

10. The laser radar system according to claim 2, characterized in that The light source module (11) comprises: a third light source (114) and a deflection angle rotation device (115) arranged on the light-emitting side of the third light source (114).

11. The laser radar system according to claim 1, characterized in that The filter in the signal filtering device (3) comprises: a polarizer, a combination of a polarizer and a quarter wave plate, a metasurface polarizer, or a multifunctional metasurface capable of filtering polarized light.

12. The laser radar system according to claim 2, characterized in that The first light beam emitted by the emitting device (2) is the same as the second light beam in the polarization detection system (1).

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