LiDAR and autonomous mobile devices

Abstract

This application relates to a lidar and an autonomous mobile device, including a transmitting chip, a beam splitter, a lens assembly, and a receiving chip. The transmitting chip emits detection light with a single polarization state; the single polarization state can be either linear or circular. The beam splitter transmits the detection light with the single polarization state and reflects light with another single polarization state; or it reflects light with a single polarization state and transmits light with another single polarization state; the other single polarization state can be a polarization state other than linear or circular. The lens assembly polarizes the received detection light and projects it onto the target detection range, and polarizes reflected light from obstacles within the target detection range and projects it onto the beam splitter. The receiving chip receives the reflected light transmitted by the beam splitter; the polarization state of the reflected light is related to the material of the obstacle. The lidar in this application can improve detection accuracy.

Description

Technical Field

[0001] This application relates to the field of lidar technology, and in particular to lidar and autonomous mobile devices. Background Technology

[0002] With the development of lidar technology, solid-state lidar technology has emerged. It adopts a binocular rangefinder optical architecture with separate transmitter and receiver, and achieves three-dimensional imaging through independent lens groups at the transmitter and receiver, thus leading to a solid-state detection method based on the rangefinder detection principle.

[0003] In related technologies, solid-state lidar projects a laser array into the field of view through a transmitting lens, and a receiving lens simultaneously collects the echo signal reflected by the target. It uses the time-of-flight (ToF) principle to calculate the distance information of each pixel, thereby generating high-density point cloud data.

[0004] However, the aforementioned off-axis optical architecture or solid-state lidar devices with separate transmitter and receiver suffer from the problem that the non-coaxial off-axis design causes the echo energy to decay nonlinearly with distance, thus limiting the detection accuracy and consistency. Utility Model Content

[0005] Therefore, it is necessary to provide a lidar and an autonomous mobile device to address the aforementioned technical problems.

[0006] In a first aspect, this application provides a lidar, comprising:

[0007] A transmitting chip is used to emit probe light with a single polarization state; the single polarization state is either a linear polarization state or a circular polarization state.

[0008] A beam-splitting component is used to transmit probe light having the single polarization state and reflect light having another single polarization state; or to reflect light having a single polarization state and transmit light having another single polarization state; wherein the other single polarization state is a polarization state other than the single polarization state among linear polarization state and circular polarization state.

[0009] A lens assembly is used to polarize the received detection light and project it onto the target detection range, and to polarize the reflected light reflected by obstacles within the target detection range and project it onto the beam splitter assembly.

[0010] A receiving chip is used to receive the reflected light transmitted by the beam splitter, wherein the polarization state of the reflected light is associated with the material of the obstacle.

[0011] In one embodiment, the type of the emitting chip includes a single-mode locked vertical-cavity surface-emitting laser chip.

[0012] In one embodiment, the lens assembly includes:

[0013] A wide-angle lens assembly, comprising a plurality of lenses with the same direction of extension of the optical axis;

[0014] A polarization state conversion component is disposed on the light-incident side or light-outcident side of the wide-angle lens assembly, or between any two adjacent lenses in the wide-angle lens assembly. The polarization state conversion component is used to convert the polarization state of the received light beam into the target polarization state.

[0015] In one embodiment, the polarization state conversion component includes a quarter-wave plate or a half-wave plate.

[0016] In one embodiment, the receiving chip includes a single-photon avalanche diode.

[0017] In one embodiment, the probe light is linearly polarized light.

[0018] In one embodiment, the beam splitting component includes a polarization beam splitter, wherein the polarization beam splitter has a Tp > 95%, a Ts < 0.5%, and a Tp:Ts ratio greater than 1000.

[0019] Wherein, Tp is the transmittance of the polarization beam splitter for incident circularly polarized light; Ts is the transmittance of the polarization beam splitter for incident linearly polarized light; and Tp:Ts is the polarization extinction ratio of the polarization beam splitter.

[0020] In one embodiment, the AOI of the beam splitter is 45°; AOI is the angle between the incident light ray and the optical interface normal of the beam splitter.

[0021] In one embodiment, the field of view of the lidar is greater than or equal to 90°.

[0022] Secondly, this application provides an autonomous mobile device, comprising:

[0023] Equipment body;

[0024] As described above, the lidar is connected to the device body.

[0025] The aforementioned lidar and autonomous mobile device include a transmitting chip, a beam splitter, a lens assembly, and a receiving chip. The transmitting chip emits a probe light with a single polarization state, which can be either linear or circular polarization. The beam splitter transmits the probe light with a single polarization state and reflects light with another single polarization state; or it reflects light with a single polarization state and transmits light with another single polarization state, which can be either linear or circular polarization. The lens assembly polarizes the received probe light and projects it onto the target detection range, and polarizes reflected light from obstacles within the target detection range and projects it onto the beam splitter. The receiving chip receives the reflected light transmitted by the beam splitter; the polarization state of the reflected light is related to the material of the obstacle. Because the transmitting chip of the lidar in this application emits a probe light with a single polarization state, the polarization pattern of the output laser can be fixed, avoiding beam dispersion and uncertainty in polarization direction, thus improving near-field energy utilization and detection accuracy. Furthermore, both the probe light and the reflected light from the obstacle are transmitted through a lens assembly, forming a coaxial optical architecture for transmission and reception. The transmission and reception share a single lens assembly, which, combined with a beam splitter, separates the probe light and reflected light according to their polarization states. This achieves optical isolation of beams with different single polarization states, suppresses stray light, eliminates the off-axis baseline, enables zero-blind-zone detection, and improves detection accuracy. Moreover, since the probe light emitted by the lidar and the reflected light from the obstacle in this application are transmitted through the same lens assembly, there is no need for two sets of lenses, which not only reduces the size but also significantly lowers lens costs. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is one of the structural schematic diagrams of a lidar in one embodiment of this application;

[0028] Figure 2 This is a second schematic diagram of the structure of a lidar in one embodiment of this application;

[0029] Figure 3 This is a schematic diagram of a polarization state conversion component disposed on the light-incident side of a wide-angle lens assembly in one embodiment of this application;

[0030] Figure 4This is a schematic diagram of a polarization state conversion component disposed on the light-emitting side of a wide-angle lens assembly in one embodiment of this application;

[0031] Figure 5 This is a schematic diagram of a polarization state conversion component disposed between any two adjacent lenses in a wide-angle lens assembly according to an embodiment of this application;

[0032] Figure 6 This is a schematic diagram of the AOI angle of the beam-splitting component in one embodiment of this application;

[0033] Figure 7 This is the third schematic diagram of the structure of the lidar in one embodiment of this application.

[0034] Explanation of icon numbers:

[0035] 100: LiDAR; 110: Transmitter chip; 111: Single-mode locked vertical cavity surface-emitting laser chip; 120: Beam splitter assembly; 121: Polarization beam splitter; 130: Lens assembly; 131: Wide-angle lens assembly; 132: Polarization state conversion assembly; 1321: Quarter wave plate; 140: Receiver chip; 141: SPAD detector; 200: Obstacle. Detailed Implementation

[0036] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0037] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0038] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0039] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0040] In related technical fields, the design of separate transmit and receive lenses is a prerequisite for solid-state lidar to achieve "one-time area array coverage." If the transmit and receive lenses share a single lens (coaxial architecture), the emitted and reflected light from the area array laser will interfere with each other, resulting in signal saturation at close range and weak signal at long range, failing to meet detection requirements. Therefore, in related technical fields, solid-state lidar generally adopts a binocular rangefinder laser architecture. The rangefinder architecture is relative to the coaxial architecture. A rangefinder architecture can be understood as having parallel but not overlapping optical axes, with a certain baseline distance, i.e., the horizontal / vertical distance between the centers of the two lenses. A coaxial architecture can be understood as having completely overlapping optical paths for the emitted and received light (such as some single-beam lidars), with no offset.

[0041] In related technologies, the purpose of designing solid-state lidar with a side-axis architecture is to prevent emitted light from directly interfering with the receiver. Solid-state lidar has high transmission power (requiring coverage of tens of meters of detection range). If the transmitter and receiver are coaxial, a large amount of unreflected emitted light will directly enter the receiver, causing the receiving sensor to be unable to identify the weak reflected light signal. The side-axis design, through "optical path offsetting," physically isolates direct crosstalk, ensuring the accuracy of the received signal.

[0042] However, due to the paraxial effect, solid-state lidar with a paraxial architecture has a certain proximity blind zone.

[0043] In some embodiments, this application provides a lidar 100. The lidar 100 in this application embodiment may include a transmitting chip 110, a beam splitting component 120, a lens component 130, and a receiving chip 140. The transmitting chip 110 is used to emit detection light with a single polarization state; the single polarization state is one of linear polarization state and circular polarization state.

[0044] The beam splitter 120 is used to transmit probe light with a single polarization state and reflect light with another single polarization state; or to reflect light with a single polarization state and transmit light with another single polarization state; the other single polarization state is a polarization state other than a single polarization state among linear polarization state and circular polarization state.

[0045] The lens assembly 130 is used to polarize the received detection light and project it onto the target detection range, and to polarize the reflected light reflected by the obstacle 200 within the target detection range and project it onto the beam splitter assembly 120; the receiving chip 140 is used to receive the reflected light transmitted by the beam splitter assembly 120; the polarization state of the reflected light is related to the material of the obstacle 200.

[0046] The reflective chip is a laser chip capable of outputting laser light with a fixed single polarization. For example, the reflective chip can output linearly polarized light or circularly polarized light. The reflective chip can be a VCSEL (Vertical-Cavity Surface-Emitting Laser) chip.

[0047] The beam splitter 120 can be any optical component capable of separating an incident beam according to its polarization pattern. For example, the beam splitter 120 may include a polarization-selective optical element, such as a polarizing beam splitter prism. See also... Figure 1 , Figure 1 The diagram shows one of the structural schematics of a lidar 100 according to an embodiment of this application. The beam splitter 120 can transmit probe light with a single polarization state and reflect light with another single polarization state. For example, the beam splitter 120 can transmit linearly polarized light and reflect circularly polarized light. The polarization state of the probe light can be linearly polarized, and the other single polarization state of the light can be circularly polarized.

[0048] Another example is shown in Appendix Figure 2 , attached Figure 2 This is a second schematic diagram of the structure of a lidar 100 according to one embodiment of this application. The beam splitter 120 can transmit light with another single polarization state and reflect probe light with a single polarization state. For example, the beam splitter 120 can transmit circularly polarized light and reflect linearly polarized light. The polarization state of the probe light can be circularly polarized, and the other single polarization state of the light can be linearly polarized.

[0049] In this embodiment, the probe light is emitted from the beam splitter 120 and the lens assembly 130 to the obstacle 200 in the target detection range. The reflected light reflected by the obstacle 200 is transmitted through the lens assembly 130 and enters the beam splitter 120. After being filtered by the beam splitter 120, it enters the receiver chip 140, realizing single-aperture transmission and reception isolation, and forming a coaxial optical architecture for transmission and reception, which can eliminate the off-axis blind zone and suppress stray light.

[0050] The lens assembly 130 includes at least one optical element capable of polarization control of the received light beam. For example, the lens assembly 130 can convert linearly polarized probe light into circularly polarized light for emission and restore reflected light to linearly polarized light orthogonal to the original direction. This achieves transmit / receive isolation, suppresses near-field scattering stray light, eliminates the off-axis blind zone, and ultimately improves the detection accuracy of the lidar 100 within the same lens assembly 130.

[0051] The receiver chip 140 can convert optical signals into digital signals, enabling high sensitivity, high time resolution, and chip-level detection capabilities. The receiver chip 140 and the transmitter chip 110 constitute the core photoelectric conversion unit of the all-solid-state Flash (area array) lidar.

[0052] The processor of the lidar 100 analyzes the reflected light fed back by the receiving chip 140 and the detection light emitted by the transmitting chip 110 to obtain information related to the obstacle 200, thereby achieving accurate detection of the obstacle 200 within the target detection range.

[0053] The polarization state of the reflected light is closely related to factors such as the material, surface morphology, and incident angle of the obstacle 200. Different materials have different polarization-selective reflection or absorption characteristics of light, so the processor can identify and classify the obstacle 200 based on this characteristic.

[0054] It is understandable that the obstacle 200 within the target detection range is the reflected light based on the detection light; therefore, the polarization state of the reflected light is naturally related to the polarization state of the detection light. The essential difference between linearly polarized and circularly polarized light beams lies in their vibration direction: linear light vibrates perpendicular to the incident plane, while circularly polarized light vibrates parallel to the incident plane. The change in polarization state after reflection is mainly determined by the optical properties of the obstacle 200 material (such as dielectric constant and surface roughness) and the incident conditions (such as the incident angle), with the material being the core factor. Differences in the atomic structure and electron distribution of different materials will lead to different reflection coefficients (such as reflected light intensity or incident light intensity) and phase changes for linearly polarized and circularly polarized light, ultimately manifesting as differences in the polarization state of the reflected light. The key distinguishing dimensions are whether the material is conductive (metal / non-metal) and whether the surface is smooth (specular / diffuse).

[0055] For example, taking an obstacle 200 made of metal, the polarization state of the reflected light from a metal obstacle 200 is not significantly different from that of S-polarized and P-polarized light. The intensity of the reflected light can be used to determine whether the obstacle 200 is metal or non-metal. Alternatively, taking an obstacle 200 made of non-metal, the difference in reflection between S-polarized and P-polarized light is significant. For a transparent or semi-transparent non-metallic obstacle 200, if the laser radar 100 emits S-polarized detection light, the reflected light will be partially polarized light dominated by S-polarized light (the intensity of S-polarized light is much higher than that of P-polarized light); if the laser radar 100 emits P-polarized detection light, the reflected light will be weakly partially polarized light (the intensity of P-polarized light is low). For an opaque, non-metallic obstacle 200, if the surface of the obstacle 200 is smooth, and if the LiDAR 100 emits S-polarized probe light, the reflected light will be partially polarized light dominated by S-polarized light (the intensity of S-polarized light is much higher than that of P-polarized light); if the LiDAR 100 emits P-polarized probe light, the reflected light will be weakly partially polarized light (the intensity of P-polarized light is low). If the surface of the obstacle 200 is rough, the diffuse reflection of the rough surface will disrupt the vibration direction of the S / P light, and the polarization component will be dispersed. The degree of polarization will decrease significantly with increasing roughness. Therefore, regardless of whether the LiDAR 100 emits S-polarized or P-polarized probe light, the reflected light will be weakly partially polarized light close to natural light.

[0056] In this embodiment, the emitting chip 110 of the lidar 100 is used to emit a probe light with a single polarization state, which can fix the polarization mode of the output laser, avoid beam dispersion and polarization uncertainty, and improve near-field energy utilization and detection accuracy. Furthermore, both the probe light and the reflected light from the obstacle 200 are transmitted through the lens assembly 130, forming a coaxial optical architecture for transmission and reception. The transmission and reception share a single lens assembly 130. Combined with the beam splitter 120, the probe light and reflected light are split according to their polarization states, thereby achieving optical isolation of beams with different single polarization states, suppressing stray light, eliminating the off-axis baseline, achieving zero-blind-zone detection, and improving detection accuracy. Moreover, since the probe light emitted by the lidar 100 and the reflected light from the obstacle 200 are transmitted through the same lens assembly 130, two sets of lenses are not required, which not only reduces the size but also significantly reduces lens costs.

[0057] In some embodiments, the type of emitting chip includes a single-mode locked vertical-cavity surface-emitting laser chip.

[0058] Compared to multimode VCSELs, which exhibit complex optical field distributions and whose beam direction becomes diffused and polarization uncertain due to interference between different modes, this embodiment utilizes a single-mode locked vertical-cavity surface-emitting laser chip. Single-mode polarization-locked VCSELs enable single-mode output, thereby fixing the polarization pattern of the output laser and improving detection accuracy.

[0059] In some embodiments, the lens assembly 130 may include a wide-angle lens assembly 131 and a polarization state conversion assembly 132. The wide-angle lens assembly 131 includes a plurality of lenses with the same optical axis extension direction; the polarization state conversion assembly 132 is disposed on the light-incident side or light-outcident side of the wide-angle lens assembly 131, or between any two adjacent lenses in the wide-angle lens assembly 131, and the polarization state conversion assembly 132 is used to convert the polarization state of the received light beam into a target polarization state.

[0060] For example, see Appendix Figure 3 , attached Figure 3 This illustration shows a schematic diagram of a polarization state conversion component 132 disposed on the light-incident side of a wide-angle lens component 131 in one embodiment of this application; another exemplary embodiment is shown in the appendix. Figure 4 , attached Figure 4 This illustration shows a schematic diagram of a polarization state conversion component 132 disposed on the light-emitting side of a wide-angle lens assembly 131 in one embodiment of this application; as another example, taking a wide-angle lens assembly 131 comprising three lenses as an example, see attached diagram. Figure 5 , attached Figure 5 This illustration shows a schematic diagram of a polarization state conversion component 132 disposed between any two adjacent lenses in a wide-angle lens assembly 131 according to an embodiment of this application.

[0061] In this embodiment, the wide-angle lens assembly 131 can be an optical component consisting of multiple lens units with negative optical power (negative optical power: the ability of a lens to diverge parallel light) arranged sequentially along the optical axis and equipped with corresponding positive optical power compensation lens groups, enabling the capture of a large area of ​​scenery in a single imaging session. The wide-angle lens assembly 131 in this embodiment can achieve a longer back working distance while maintaining a large field of view through an anti-long-range structure or a symmetrical structure, and can extend the field of view of the transmitting chip 110 and the receiving chip 140 by using aspherical or cemented surfaces to correct distortion and aberrations, thereby achieving solid-state area array illumination and echo capture.

[0062] The polarization state conversion component 132 in this embodiment may include a micro-optical unit capable of converting the polarization state of the beam in the transceiver link of the lidar 100 into another orthogonal or specified polarization state as needed, so as to achieve transceiver isolation, stray light suppression and zero blind zone detection within the same lens.

[0063] In some embodiments, the polarization state conversion component includes a quarter-wave plate or a half-wave plate.

[0064] For example, the polarization state conversion component may include a quarter-wave plate, which can convert a probe light with a single polarization state into a probe light with another single polarization state, preventing the polarization state of the probe light with the other single polarization state from being reversed after specular reflection. The reflected light passes through the quarter-wave plate again, allowing only the target reflected light with the reversed polarization state to pass through, while the stray light reflected directly (without polarization reversal) is filtered out, thus resisting specular reflection interference.

[0065] In another exemplary embodiment, the polarization state conversion component may include a half-wave plate, which can calibrate the polarization direction of the incident probe light or reflected light, thereby reducing energy loss.

[0066] In some embodiments, the receiving chip includes a single-photon avalanche diode.

[0067] In this embodiment, the receiving chip may include a single-photon avalanche diode or a single-photon avalanche diode (SPAD) array. A single photon entering a single-photon avalanche diode can trigger a self-sustaining avalanche, instantly outputting a digital pulse, thereby achieving precise detection of the reflected light.

[0068] It is understood that in other embodiments, the receiver chip may also include a SIPM (Silicon Photomultiplier) and an APD (Avalanche Photodiode), and is not limited thereto.

[0069] In some embodiments, the probe light is linearly polarized light. For example, the probe light may be S-polarized light (S-polarized light, vertically polarized light, vertical: perpendicular to the plane of incidence).

[0070] In this embodiment, the emission chip directly emits ray-polarized light, instead of obtaining it by polarizing naturally polarized light, which can reduce the loss of optical emission efficiency and improve the emission efficiency.

[0071] In some embodiments, the beam splitting component includes a polarizing beam splitter (PBS), wherein the polarizing beam splitter has a Tp > 95%, a Ts < 0.5%, and a Tp:Ts ratio greater than 1000; wherein Tp is the transmittance of the polarizing beam splitter for incident circularly polarized light; Ts is the transmittance of the polarizing beam splitter for incident linearly polarized light; and Tp:Ts is the polarization extinction ratio of the polarizing beam splitter.

[0072] For example, the Tp of the polarization beam splitter can be 96%, 97%, 98%, 99%, 100%, etc., and is not limited thereto.

[0073] For example, the Ts of the polarization beam splitter can be 0.4%, 0.3%, 0.2%, 0.1%, etc., and is not limited thereto.

[0074] In this embodiment, the polarization beam splitter has a Tp > 95%, a Ts < 0.5%, and a Tp:Ts ratio greater than 1000, enabling it to accurately split beams of different single polarization states.

[0075] In some embodiments, see Appendix Figure 6 , attached Figure 6 A schematic diagram of the AOI (Angle of Incidence) angle of a beam splitter component in one embodiment of this application is shown. In this embodiment, the AOI of the beam splitter component 120 is 45°; AOI is the angle between the incident ray and the optical interface normal of the beam splitter component 120.

[0076] In this embodiment, the AOI of the beam splitter 120 is 45°, which can accurately refract the probe light to the lens assembly 130 and transmit the reflected light to the receiver chip 140, providing a beam splitting angle for the coaxial transceiver architecture. Furthermore, the 45° AOI of the beam splitter 120 ensures that the primary reflected light deviates from the output path of the probe light, avoiding any impact on the receiver chip 140 receiving clean reflected light.

[0077] In some embodiments, the field of view of the lidar is greater than or equal to 90°.

[0078] In this embodiment, the lidar can achieve a coaxial transmit-receive architecture, with the transmit and receive optical axes jointly covering an unobstructed, detectable spatial angle range. The lidar's field of view can be expressed as the angle between its two edges in the vertical and horizontal directions. With a field of view greater than or equal to 90°, the lidar can form a fully solid-state wide-angle radar, reducing proximity blind spots.

[0079] In some embodiments, see Appendix Figure 7 , attached Figure 7 The third schematic diagram shows the structure of a lidar according to one embodiment of this application. The lidar in this embodiment may include a single-mode locked vertical-cavity surface-emitting laser chip 111, a polarization beam splitter 121, a wide-angle lens assembly 131, a quarter-wave plate 1321, and a SPAD detector 141. The single-mode locked vertical-cavity surface-emitting laser chip 111 emits S-polarized probe light, the polarization beam splitter 121 reflects the S-polarized probe light and transmits P-polarized light, the wide-angle lens assembly 131 provides a field of view greater than or equal to 90° for the lidar, and the quarter-wave plate 1321 changes the polarization state of the received beam.

[0080] In this embodiment, the single-mode locked vertical-cavity surface-emitting laser chip 111 of the lidar 100 emits only S-polarized probe light, which can fix the polarization of the output laser, avoid beam dispersion and polarization uncertainty, and improve near-field energy utilization and detection accuracy. Furthermore, both the probe light and the reflected light from the obstacle 200 are transmitted through a lens assembly 130 composed of a wide-angle lens assembly 131 and a quarter-wave plate 1321, forming a coaxial optical architecture for transmission and reception. The transmission and reception share a single lens assembly 130. Combined with a polarization beam splitter 121, the probe light and reflected light are split according to their polarization states, thereby achieving optical isolation of beams with different single polarization states, suppressing stray light, eliminating the paraxial baseline, achieving zero-blind-zone detection, and improving detection accuracy. Moreover, since the probe light and reflected light of the lidar 100 in this application are transmitted through the same lens assembly 130, there is no need to use two sets of lenses, which not only reduces the size but also significantly reduces lens costs.

[0081] In some embodiments, this application also provides an autonomous mobile device, including a device body and a lidar as described in any of the above embodiments. The lidar can be connected to the device body.

[0082] Among them, autonomous mobile devices can be any device that requires laser detection, such as a robot vacuum cleaner or a car.

[0083] In this embodiment, it can be understood that the autonomous mobile device in this application embodiment includes the lidar in any of the above embodiments. Based on the lidar's ability to improve near-field energy utilization and detection accuracy, reduce size, and significantly reduce lens cost, the autonomous mobile device in this application embodiment also has the above-mentioned beneficial effects.

[0084] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0085] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A lidar, characterized in that, include: The transmitting chip is used to emit probe light with a single polarization state; The single polarization state is one of linear polarization state and circular polarization state; A beam-splitting component is used to transmit probe light having the single polarization state and reflect light having another single polarization state; or to reflect light having a single polarization state and transmit light having another single polarization state; wherein the other single polarization state is a polarization state other than the single polarization state among linear polarization state and circular polarization state. A lens assembly is used to polarize the received detection light and project it onto the target detection range, and to polarize the reflected light reflected by obstacles within the target detection range and project it onto the beam splitter assembly. A receiving chip is used to receive the reflected light transmitted by the beam splitter, wherein the polarization state of the reflected light is associated with the material of the obstacle.

2. The lidar according to claim 1, characterized in that, The type of emitting chip includes a single-mode locked vertical cavity surface-emitting laser chip.

3. The lidar according to claim 1, characterized in that, The lens assembly includes: A wide-angle lens assembly, comprising a plurality of lenses with the same direction of extension of the optical axis; A polarization state conversion component is disposed on the light-incident side or light-outcident side of the wide-angle lens assembly, or between any two adjacent lenses in the wide-angle lens assembly. The polarization state conversion component is used to convert the polarization state of the received light beam into the target polarization state.

4. The lidar according to claim 3, characterized in that, The polarization state conversion component includes a quarter-wave plate or a half-wave plate.

5. The lidar according to claim 1, characterized in that, The receiving chip includes a single-photon avalanche diode.

6. The lidar according to any one of claims 1 to 5, characterized in that, The detection light is linearly polarized light.

7. The lidar according to claim 6, characterized in that, The beam splitting component includes a polarization beam splitter, wherein the polarization beam splitter has a Tp > 95%, a Ts < 0.5%, and a Tp:Ts ratio greater than 1000; Wherein, Tp is the transmittance of the polarization beam splitter for incident circularly polarized light; Ts is the transmittance of the polarization beam splitter for incident linearly polarized light; and Tp:Ts is the polarization extinction ratio of the polarization beam splitter.

8. The lidar according to claim 1, characterized in that, The AOI of the beam splitter is 45°; AOI is the angle between the incident ray and the optical interface normal of the beam splitter.

9. The lidar according to claim 1, characterized in that, The field of view of the lidar is greater than or equal to 90°.

10. An autonomous mobile device, characterized in that, include: Equipment body; The lidar as described in any one of claims 1 to 9, wherein the lidar is connected to the device body.

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