Laser radar and beam splitter prism

Abstract

The disclosure discloses a laser radar and a light splitting prism. The laser radar comprises a light emitting component, a light receiving component, an imaging component and a light splitting prism. The light emitting component is configured to emit probe light. The light receiving component is configured to receive echo light formed by the probe light after being reflected by an object. The imaging component is configured to receive ambient light. The light splitting prism comprises a polarization light splitting surface and a first wavelength light splitting surface. The polarization light splitting surface is configured to separate the probe light and the echo light. The first wavelength light splitting surface is configured to separate the echo light and the ambient light. The laser radar is configured to determine depth information of the object based on the echo light, determine image information based on the ambient light, and determine fusion information based on the depth information and the image information.

Description

Technical Field

[0001] This disclosure relates to the field of lidar technology, specifically to a lidar and a beam splitter prism. Background Technology

[0002] With the rapid development of LiDAR technology, the integration of LiDAR and cameras has become a mainstream trend in the industry. Currently, most common fusion solutions employ discrete modules. For example, one or more LiDAR modules and one or more camera modules are installed in a single housing. This approach has some drawbacks. Firstly, the discrete design results in a large number of modules, increasing system complexity and manufacturing costs, as well as the size and weight of the equipment. Secondly, each module needs to be individually assembled, adjusted, and fixed, which can easily lead to inaccuracies due to mechanical vibration, temperature changes, and other factors during long-term use. Summary of the Invention

[0003] In view of this, the present disclosure provides a lidar and a beam splitter prism that can realize the fusion of depth data and image data of lidar, thereby improving the integration.

[0004] This disclosure provides a lidar, including: a light emitting component for emitting probe light; a light receiving component for receiving echo light formed after the probe light is reflected by an object; an imaging component for receiving ambient light; and a beam splitter prism including a polarization beam splitter surface and a first wavelength beam splitter surface; the polarization beam splitter surface is used to separate the probe light and the echo light; the first wavelength beam splitter surface is used to separate the echo light and the ambient light; the lidar is configured to determine the depth information of an object based on the echo light and to determine image information based on the ambient light; the lidar is also configured to determine fusion information based on the depth information and the image information.

[0005] Optionally, the polarization beam-splitting surface and the first wavelength beam-splitting surface are disposed on different surfaces of the beam-splitting prism.

[0006] Optionally, the beam splitter includes four prisms, with the polarization beam splitting surface and the first wavelength beam splitting surface disposed on surfaces close to each other on the four prisms; the angle between the polarization beam splitting surface and the first wavelength beam splitting surface is greater than 0°.

[0007] Optionally, the lidar also includes a first lens located in the optical path of the probe light, the first lens being positioned downstream of the optical path of the beam splitter.

[0008] Optionally, the lidar further includes at least one of the following: a second lens located in the optical path of the probe light and disposed between the light emitting component and the beam splitter; or a third lens located in the optical path of the echo light and disposed between the light receiving component and the beam splitter.

[0009] Optionally, the lidar also includes a scanner; the scanner is used to receive probe light transmitted from the first lens and transmit the probe light to an external field of view.

[0010] Optionally, the lidar further includes: a light separation element located in the optical path of the probe light and disposed between the first lens and the scanner; the light separation element is used to reflect the probe light and the echo light and transmit ambient light, or the light separation element is used to transmit the probe light and the echo light and reflect ambient light.

[0011] Optionally, the optical separation element includes a second wavelength beam splitter.

[0012] Optionally, the light-splitting element includes a reflective surface.

[0013] Optionally, the lidar also includes a filter disposed between the first wavelength beam splitter and the light receiving component.

[0014] Optionally, a filter is disposed on the surface of the beam splitter near the light receiving component.

[0015] Optionally, the lidar further includes: a phase modulator; the phase modulator is configured to modulate the phase of the probe light and the echo light; the phase modulator is disposed downstream of the optical path of the polarization beam splitter along the optical path of the probe light; the probe light has a first polarization state when it is transmitted to the polarization beam splitter; the echo light has a second polarization state when it is transmitted to the polarization beam splitter, and the polarization direction of the first polarization state is different from the polarization direction of the second polarization state.

[0016] Optionally, the polarization direction of the first polarization state is perpendicular to the polarization direction of the second polarization state.

[0017] Optionally, the phase modulator includes a quarter-wave plate.

[0018] Optionally, the phase modulator is disposed on the surface of the beam splitter prism.

[0019] This disclosure provides a beam splitter, comprising: a polarization beam splitter surface for transmitting light of a first polarization state and reflecting light of a second polarization state, or reflecting light of a first polarization state and transmitting light of a second polarization state; wherein the polarization direction of the first polarization state is perpendicular to the polarization direction of the second polarization state; and a first wavelength beam splitter surface for transmitting light within a first wavelength range and reflecting light outside the first wavelength range, or reflecting light within the first wavelength range and transmitting light outside the first wavelength range; wherein the angle between the polarization beam splitter surface and the first wavelength beam splitter surface is greater than 0°.

[0020] Optionally, the polarization beam-splitting surface and the first wavelength beam-splitting surface are respectively disposed on different surfaces of the beam-splitting prism.

[0021] Optionally, the beam splitter includes four prisms, with the polarization beam splitting surface and the first wavelength beam splitting surface disposed on surfaces close to each other on the four prisms.

[0022] In the lidar provided in this disclosure, the beam-splitting prism can separate both the probe light and the echo light, as well as the echo light and the ambient light. The optical emitting component, optical receiving component, and imaging component of the lidar can share the beam-splitting prism, reducing the number of optical components and improving integration. The optical emitting component, optical receiving component, and imaging component can share part of the optical path through the beam-splitting prism, eliminating the need for independent assembly and adjustment. The lidar provided in this disclosure is less prone to misalignment during long-term use. The lidar exhibits high reliability and stability. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the following description of the embodiments will be provided as examples. The drawings described below are merely embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort. The drawings are used to provide a further understanding of this disclosure and constitute a part of the specification. They are used together with the embodiments of this disclosure to explain this disclosure and do not constitute a limitation of this disclosure.

[0024] Figure 1 This is a schematic diagram of the structure of a lidar provided in some embodiments of this disclosure.

[0025] Figure 2 This is a schematic diagram of the structure of a beam splitter provided in some embodiments of this disclosure.

[0026] Figure 3 This is a schematic diagram of the structure of a beam splitter provided in some embodiments of this disclosure.

[0027] Figure 4 This is a schematic diagram of the structure of a beam splitter provided in some embodiments of this disclosure.

[0028] Figure 5 This is a schematic diagram of the structure of a beam splitter provided in some embodiments of this disclosure.

[0029] Figure 6 This is a schematic diagram of the structure of a beam splitter provided in some embodiments of this disclosure.

[0030] Figure 7 This is a schematic diagram of the structure of a beam splitter provided in some embodiments of this disclosure.

[0031] Figure 8 This is a schematic diagram of the structure of a beam splitter provided in some embodiments of this disclosure.

[0032] Figure 9This is a schematic diagram of the structure of a beam splitter provided in some embodiments of this disclosure.

[0033] Figure 10 This is a schematic diagram of the structure of a lidar provided in some embodiments of this disclosure.

[0034] Figure 11 This is a schematic diagram of the structure of a lidar provided in some embodiments of this disclosure.

[0035] Figure 12 This is a schematic diagram of the structure of a lidar provided in some embodiments of this disclosure.

[0036] Figure 13 This is a schematic diagram of the structure of an optical separation element provided in some embodiments of this disclosure.

[0037] Figure 14 This is a schematic diagram of the structure of an optical separation element provided in some embodiments of this disclosure.

[0038] Figure 15 This is a schematic diagram of the structure of an optical separation element provided in some embodiments of this disclosure.

[0039] Figure 16 This is a schematic diagram of the structure of a lidar provided in some embodiments of this disclosure. Detailed Implementation

[0040] In the following description, only certain exemplary embodiments are shown. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this disclosure. Therefore, the drawings and description are to be considered exemplary in nature and not restrictive.

[0041] In the description of this disclosure, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this disclosure 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 disclosure. 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.

[0042] In the description of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0043] In this disclosure, the terms "or" and "and / or" describe the relationship between related objects and indicate a non-exclusive inclusion. For example, "A and / or B" and "A or B" can include: the presence of only "A", the presence of only "B", and the presence of both "A" and "B", where "A" and "B" can be singular or plural. As another example, "A, B, and / or C" and "A, B, or C" can include: the presence of only "A", the presence of only "B", the presence of only "C", the presence of both "A" and "B", the presence of both "A" and "C", the presence of both "B" and "C", and the presence of both "A", "B", and "C", where "A", "B", and "C" can be singular or plural. Furthermore, the symbol " / " in this disclosure indicates an "or" relationship between the related objects before and after the symbol. In this disclosure, the term "at least one A or B" has the same meaning as "A or B" described above. The term "at least one A, B or C" has the same meaning as "A, B or C" above.

[0044] The following disclosure provides many different implementations or examples for carrying out different structures of this disclosure. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this disclosure. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various implementations and / or arrangements discussed.

[0045] The mainstream fusion schemes for existing LiDAR and cameras employ discrete modules. LiDAR and cameras are mechanically fixed and combined as independent optical subsystems in an external structure. Point cloud data acquired by the LiDAR and image data acquired by the camera are aligned, matched, and fused at the algorithm level to obtain richer and more reliable environmental perception information. For example, one or more LiDAR modules and one or more camera modules are installed in a single housing. The LiDAR data and camera data are fused through post-processing. This approach has several problems. First, the discrete design results in a large number of modules and low system integration. This not only increases system complexity and manufacturing costs but also increases the size and weight of the equipment. Second, each module needs to be individually assembled and fixed, which can easily lead to inaccuracies due to mechanical vibration, temperature changes, and other factors during long-term use.

[0046] Firstly, this disclosure provides a lidar. The lidar includes a beam splitter prism. The beam splitter prism can separate the probe light and the echo light, as well as the echo light and the ambient light. The optical emitting component, optical receiving component, and imaging component of the lidar can share the beam splitter prism, reducing the number of optical components in the lidar and improving integration. The optical emitting component, optical receiving component, and imaging component can share part of the optical path through the beam splitter prism, eliminating the need for independent assembly and adjustment. The lidar provided by this disclosure is less prone to misalignment during long-term use. The lidar has high reliability and stability.

[0047] Secondly, this disclosure also provides a beam splitter. The beam splitter includes a polarization beam splitter surface and a first wavelength beam splitter surface. The polarization beam splitter surface is used to transmit light of a first polarization state and reflect light of a second polarization state. Alternatively, the polarization beam splitter surface is used to reflect light of the first polarization state and transmit light of the second polarization state. The polarization direction of the first polarization state is perpendicular to the polarization direction of the second polarization state. The first wavelength beam splitter surface is used to transmit light within a first wavelength range and reflect light outside the first wavelength range. Alternatively, the first wavelength beam splitter surface is used to reflect light within the first wavelength range and transmit light outside the first wavelength range. The angle between the polarization beam splitter surface and the first wavelength beam splitter surface is greater than 0°.

[0048] The exemplary embodiments provided in this disclosure are described below with reference to the accompanying drawings. It should be understood that the exemplary embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0049] Figure 1 Schematic diagrams of the structure of lidar provided in some embodiments of this disclosure are shown. For example... Figure 1 As shown, the lidar includes a light emitting component 110, a light receiving component 120, an imaging component 130, and a beam splitter 140.

[0050] The optical emitting assembly 110 is used to emit a probe light L1. The optical emitting assembly 110 may include one or more lasers. The lasers are used to provide the probe light L1. For example, the lasers may include semiconductor lasers such as vertical-cavity surface-emitting lasers (VCSELs), edge-emitting lasers (EELs), or distributed feedback (DFB) lasers. Alternatively, the lasers may include solid-state lasers or fiber lasers. In one example, the laser may include a linearly polarized laser.

[0051] The light receiving component 120 is used to receive the echo light L2 formed after the probe light L1 is reflected by the object. The light receiving component 120 may include one or more photodetectors. The photodetectors are used to receive the echo light L2 and convert the optical signal into an electrical signal. For example, the photodetectors may include a single photon avalanche diode (SPAD), a silicon photomultiplier (SiPM), an avalanche photodiode (APD), or a photodiode (PD).

[0052] Imaging component 130 is used to receive ambient light L3. Imaging component 130 includes one or more image sensors. The image sensors are used to receive ambient light L3 and convert it into corresponding image data. For example, the image sensors may include image sensors based on complementary metal-oxide-semiconductor (CMOS) technology.

[0053] LiDAR can determine the depth information of an object based on the echo light L2 and the image information based on the ambient light. LiDAR can also determine fused information based on the depth and image information.

[0054] The optical receiving component 120 can receive the echo light L2 reflected back by the object. By analyzing and processing the optical signal of the echo light L2 (e.g., measuring time of flight, phase change, or frequency modulation), the depth information of the object can be determined. The depth information includes, for example, three-dimensional spatial data such as the object's position, coordinates, distance, or velocity. For example, a lidar can determine the object's distance based on the time difference between the echo light L2 and the probe light L1. Exemplarily, the lidar also includes a controller. The controller can determine the object's depth information.

[0055] Imaging component 130 can receive ambient light L3 from an external scene. Ambient light L3 typically contains visible spectrum information, which, after being converted into an electrical signal by the image sensor of imaging component 130, allows the determination of image information of the external scene. Image information includes, for example, light intensity, color, and texture information. Exemplarily, a controller can determine the image information.

[0056] Based on depth and image information, fused information can be generated. This fused information is not a simple superposition of the two types of information, but rather achieves pixel-level or feature-level complementarity and organic combination of depth and image data. For example, the controller can determine the fused information based on depth and image information.

[0057] Figure 1 The light emitting component 110, light receiving component 120, and imaging component 130 shown are only schematic structures, and their specific positions are not fixed. In practical applications, the positions of the three components can be set according to requirements to meet different optical layouts and functional requirements.

[0058] The beam splitter 140 includes a polarization beam splitter S1 and a first wavelength beam splitter S2. The polarization beam splitter S1 is used to separate the probe light L1 and the echo light L2. The first wavelength beam splitter S2 is used to separate the echo light L2 and the ambient light L3.

[0059] In some embodiments, such as Figure 1 As shown, the polarization beam splitter S1 reflects the probe light L1 and transmits the echo light L2. This embodiment does not impose specific limitations on this. In practical applications, the configuration of the polarization beam splitter S1 can be adjusted accordingly for different types or combinations of polarization states of the probe light L1 and the echo light L2. For example, the polarization beam splitter S1 can also transmit the probe light L1 and reflect the echo light L2, adapting to different optical layouts and functional requirements.

[0060] In some embodiments, such as Figure 1 As shown, the first wavelength beam splitter S2 transmits the echo light L2 and reflects the ambient light L3. This embodiment does not impose specific limitations on this. In practical applications, the first wavelength beam splitter S2 can also reflect the echo light L2 and transmit the ambient light L3, adapting to different optical layouts and functional requirements.

[0061] Figure 1 The polarization beam-splitting surface S1 and the first wavelength beam-splitting surface S2 shown are only schematic structures, and their specific positions are not fixed. In practical applications, the positions of the polarization beam-splitting surface S1 and the first wavelength beam-splitting surface S2 can be set according to requirements to meet different optical layouts and functional requirements.

[0062] In the lidar provided in this embodiment, the beam splitter prism 140 can separate the probe light L1 and the echo light L2, as well as the echo light L2 and the ambient light L3. Depth information can be determined based on the probe light L1 emitted by the light emitting component 110 and the echo light L2 received by the light receiving component 120. Image information can be determined based on the ambient light L3 received by the imaging component 130. The lidar of this disclosure can achieve the fusion of depth information and image information. This disclosure overcomes the limitations of single-sensor technology. Depth information provides accurate three-dimensional geometric structure, but is not sensitive to object surface characteristics (such as color and text). Image information provides rich two-dimensional texture, but lacks depth dimension data. Fusion of the two at the system level achieves strong complementarity between spatial geometric information and surface texture information, enabling the perception system to simultaneously "see" the outline and distance of objects and "identify" their details and colors, significantly improving the overall understanding and analysis capability of complex environments.

[0063] The light-emitting component 110, light-receiving component 120, and imaging component 130 of the lidar share a beam-splitting prism 140, which can improve integration and reduce costs. If the lidar is used inside a cabin, it can also reduce the cabin space occupied by the lidar.

[0064] In existing LiDAR and camera fusion systems, the light emitting component, light receiving component, and imaging component each require independent lenses. This approach can be referred to as tricular. The LiDAR disclosed herein allows the light emitting component, light receiving component, and imaging component to share a portion of the optical path and lens via a beam splitter prism that integrates polarization and wavelength splitting functions. The LiDAR of this disclosure can achieve monocular operation, eliminating the need for independent assembly and adjustment of different optical modules, and is less prone to misalignment during long-term use. Furthermore, by replacing tricular with monocular operation, the LiDAR of this disclosure reduces the number and area of ​​exposed lenses after installation, which is beneficial for the design of the LiDAR mounting platform. Moreover, the hardware-based "monocular" integration ensures that the coordinate system correspondence between depth and image data can be predetermined and remains stable during application. This greatly simplifies the complexity of the fusion algorithm and improves the accuracy and efficiency of the fusion process.

[0065] In some embodiments of this disclosure, the beam-splitting prism includes at least two prisms. The at least two prisms can be bonded together in pairs. The bonding surfaces of the two prisms can form a polarization beam-splitting surface or a first wavelength beam-splitting surface.

[0066] For example, at least two prisms can be bonded together using optical or structural adhesive. Alternatively, at least two prisms can be mechanically secured using clamps, clips, or similar means. Furthermore, at least two prisms can be relatively fixed using a detachable mounting structure to facilitate future maintenance or adjustments.

[0067] In some embodiments, the beam-splitting prism includes four prisms. A polarizing beam-splitting surface and a first wavelength beam-splitting surface are disposed on surfaces close to each other on the four prisms. The angle between the polarizing beam-splitting surface and the first wavelength beam-splitting surface is greater than 0°.

[0068] like Figures 2 to 5 As shown, the beam splitter 140 includes four prisms. The four prisms include a first prism 141, a second prism 142, a third prism 143, and a fourth prism 144.

[0069] When the first prism 141 and the second prism 142 are bonded together, a first surface S12 is formed. The first surface S12 includes the surface of the first prism 141 near the second prism 142, and the surface of the second prism 142 near the first prism 141. When the third prism 143 and the fourth prism 144 are bonded together, a second surface S11 is formed. The second surface S11 includes the surface of the third prism 143 near the fourth prism 144, and the surface of the fourth prism 144 near the third prism 143. The first surface S12 and the second surface S11 form a polarizing beam-splitting surface S1.

[0070] When the first prism 141 and the third prism 143 are bonded together, a third surface S21 is formed. The third surface S21 includes the surface of the first prism 141 adjacent to the third prism 143, and the surface of the third prism 143 adjacent to the first prism 141. When the second prism 142 and the fourth prism 144 are bonded together, a fourth surface S22 is formed. The fourth surface S22 includes the surface of the second prism 142 adjacent to the fourth prism 144, and the surface of the fourth prism 144 adjacent to the second prism 142. The third surface S21 and the fourth surface S22 form a first wavelength beam-splitting surface S2.

[0071] like Figure 2 As shown, the beam splitter 140 is an X-Cube prism. The four faces of X are the third surface S21, the fourth surface S22, the second surface S11, and the first surface S12.

[0072] For example, the third surface S21 and the fourth surface S22 are provided with wavelength-selective dielectric films. The second surface S11 and the first surface S12 are provided with polarization beam-splitting films.

[0073] In some embodiments, the beam-splitting prism includes three prisms. A polarizing beam-splitting surface and a first wavelength beam-splitting surface are disposed on surfaces close to each other on the three prisms. The angle between the polarizing beam-splitting surface and the first wavelength beam-splitting surface is greater than 0°.

[0074] like Figure 6 As shown, the beam splitter 140 includes three prisms. The three prisms include a first prism 141, a second prism 142, and a third prism 143.

[0075] When the first prism 141 and the second prism 142 are bonded together, a first surface S12 is formed. The first surface S12 includes the surface of the first prism 141 near the second prism 142 and the surface of the second prism 142 near the first prism 141. When the first prism 141 and the third prism 143 are bonded together, a third surface S21 is formed. The third surface S21 includes the surface of the first prism 141 near the third prism 143 and the surface of the third prism 143 near the first prism 141. The first surface S12 and the third surface S21 form a first wavelength beam-splitting surface S2. When the second prism 142 and the third prism 143 are bonded together, a polarization beam-splitting surface S1 is formed. The polarization beam-splitting surface S1 includes the surface of the second prism 142 near the third prism 143 and the surface of the third prism 143 near the second prism 142.

[0076] For example, the polarization beam-splitting surface S1 is provided with a polarization beam-splitting film. The first surface S12 and the third surface S21 are provided with wavelength-selective dielectric films.

[0077] exist Figures 2 to 6 In the diagram, each prism is a triangular prism.

[0078] In some embodiments, the beam-splitting prism includes two prisms. A polarizing beam-splitting surface and a first wavelength beam-splitting surface are disposed on surfaces of the two prisms that are close to each other. The angle between the polarizing beam-splitting surface and the first wavelength beam-splitting surface is greater than 0°.

[0079] like Figure 7 As shown, the beam splitter 140 includes two prisms. The two prisms include a first prism 141 and a second prism 142.

[0080] When the first prism 141 and the second prism 142 are attached, a polarization beam-splitting surface S1 and a first wavelength beam-splitting surface S2 are formed. The polarization beam-splitting surface S1 includes a surface of the first prism 141 near the second prism 142 and a surface of the second prism 142 near the first prism 141. The first wavelength beam-splitting surface S2 includes another surface of the first prism 141 near the second prism 142 and another surface of the second prism 142 near the first prism 141.

[0081] For example, the polarization beam-splitting surface S1 is provided with a polarization beam-splitting film. The first wavelength beam-splitting surface S2 is provided with a wavelength-selective dielectric film.

[0082] In some embodiments of this disclosure, the polarization beam-splitting surface S1 does not coincide with the first wavelength beam-splitting surface S2, and they are not parallel.

[0083] The embodiments disclosed herein do not limit the specific shape of each prism. In practical applications, the shape of each prism can be set according to requirements to meet different optical layouts and functional requirements. For example, Figure 2 As shown, the cross-sectional shapes of the four prisms are right-angled triangles. For example, as... Figures 3 to 6 As shown, the cross-sectional shape of the four prisms can be a scalene triangle.

[0084] The embodiments disclosed herein do not limit the specific shape of the beam splitter. In practical applications, the shape of the beam splitter can be set according to requirements to meet different optical layouts and functional requirements. For example, Figure 2 and 3 As shown, the cross-sectional shape of the beam splitter 140 is square. For example, as... Figure 4 As shown, the cross-sectional shape of the beam splitter 140 can be rectangular. For example, as... Figure 5 As shown, the cross-sectional shape of the beam splitter 140 can be trapezoidal.

[0085] This disclosure does not limit the specific number of prisms included in the beam-splitting prism 140. In practical applications, the number of prisms included in the beam-splitting prism 140 can be set according to requirements to meet different optical layouts and functional requirements. For example, as Figures 2 to 5 As shown, the beam splitter 140 comprises four prisms. For example, as... Figure 6 As shown, the beam splitter 140 comprises three prisms. For example, as... Figure 7 As shown, the beam splitter 140 comprises two prisms. For example, as... Figure 8 and 9 As shown, the beam splitter 140 includes one prism.

[0086] In some embodiments, the beam-splitting prism includes a prism. A polarization beam-splitting surface and a first wavelength beam-splitting surface are disposed on two surfaces of the prism.

[0087] like Figure 8 As shown, the beam splitter 140 includes a prism, namely, the first prism 141. The angle between the polarization beam splitter S1 and the first wavelength beam splitter S2 is greater than 0°.

[0088] like Figure 9 As shown, the beam splitter 140 includes a prism, namely, the first prism 141. The angle between the polarization beam splitter S1 and the first wavelength beam splitter S2 is equal to 0°.

[0089] For example, the polarization beam splitter S1 is provided with a polarization beam splitting film, and the first wavelength beam splitter S2 is provided with a wavelength selective dielectric film.

[0090] In some embodiments of this disclosure, the polarization beam-splitting surface S1 and the first wavelength beam-splitting surface S2 are disposed on different surfaces of the beam-splitting prism 140.

[0091] In some embodiments of this disclosure, the separation of the probe light L1 and the echo light L2, as well as the separation of the echo light L2 and the ambient light L3, can be achieved through a combination of polarization beam splitters and wavelength beam splitters. Figure 10 As shown, polarization beam splitter 101 is used to separate the probe light L1 and the echo light L2. Wavelength beam splitter 102 is used to separate the echo light L2 and the ambient light L3. Figure 10 In the middle, the wavelength splitting element 102 is disposed downstream of the optical path of the echo light L2 relative to the polarization splitting element 101.

[0092] Polarizing beam splitter 101 may include a polarizing beam splitter prism, such as a Wollaston prism, a Glan-Taylor prism, or a Glan-Thompson prism. Alternatively, polarizing beam splitter 101 may include a planar optical substrate coated with a polarizing beam splitter film. Wavelength beam splitter 102 may include a dichroic mirror.

[0093] Figure 10 The polarization beam splitter 101 and wavelength beam splitter 102 shown are only schematic structures, and their specific positions are not fixed. In practical applications, their positions can be set according to requirements to meet different optical layouts and functional requirements. For example, the wavelength beam splitter 102 can be used first to separate the echo light L2 and the ambient light L3, and then the polarization beam splitter 101 can be used to separate the probe light L1 and the echo light L2.

[0094] The following is combined Figures 11 to 16 The structure of the lidar in the embodiments of this disclosure will be described.

[0095] Figure 11 This is a schematic diagram of the structure of a lidar provided in some embodiments of this disclosure.

[0096] In some embodiments of this disclosure, such as Figure 11 As shown, the lidar includes a light emitting component 110, a light receiving component 120, an imaging component 130, a beam splitter 140, and a first lens 210. The first lens 210 is located in the optical path of the probe light L1. The first lens 210 is positioned downstream of the probe light L1 relative to the beam splitter 140.

[0097] The first lens 210 is used to collimate the probe light L1. The first lens 210 is also used to focus the echo light L2. The first lens 210 is also used to focus the ambient light L3.

[0098] The light emitting component 110, the light receiving component 120, and the imaging component 130 share the same first lens 210 via the beam splitter 140. The first lens 210 is not only located in the optical path of the probe light L1, but also in the optical path of the echo light L2 and the optical path of the ambient light L3.

[0099] Compared to related technologies that require multiple separate lenses for the optical paths of the probe light, echo light, and ambient light, this embodiment of the present disclosure multiplexes the optical paths of the probe light L1, echo light L2, and ambient light L3 using a first lens 210. The lidar of this disclosure can achieve monocular operation without the need for independent assembly and adjustment of different optical modules, and is less prone to misalignment during long-term use. Lidar misalignment indicates that factors such as vibration, temperature changes, or material aging during long-term use cause a shift in the relative position or angle between the optical modules within the lidar. This shift causes the probe light, echo light, and ambient light to deviate from their originally calibrated optical paths. A relative deviation occurs in the correspondence between the field of view of the receiving optical path and the field of view of the imaging optical path, affecting the normal transmission of light and the accurate reception of signals.

[0100] If multiple discrete lenses are used to correspond to different optical paths, for example, one lens is set on each of the three optical paths, when any lens is displaced due to vibration or deformation, the correspondence between two or all three of the following will deviate: the emission field of view corresponding to the light emitting component, the receiving field of view corresponding to the light receiving component, and the imaging field of view corresponding to the imaging component. The data collected by the light receiving component and the imaging component cannot be accurately matched spatially, leading to misalignment. In this embodiment, the first lens 210 is multiplexed across the three optical paths. Even if the first lens 210 as a whole is displaced or shifted, the correspondence between the emission field of view corresponding to the light emitting component 110, the receiving field of view corresponding to the light receiving component 120, and the imaging field of view corresponding to the imaging component 130 remains synchronized and constant, fundamentally avoiding alignment failure caused by relative displacement between discrete lenses.

[0101] For example, the first lens 210 serves as a three-in-one multiplexed lens. The lidar disclosed herein can replace a three-lens system with a monocular one. On the one hand, this reduces the number and area of ​​lenses exposed after installation, which is beneficial for the shape design of the lidar mounting carrier. On the other hand, it increases integration and reduces costs. If the lidar is used inside a cabin, it can also reduce the cabin space occupied by the lidar.

[0102] The lidar of this embodiment integrates the probe light L1, echo light L2 and ambient light L3 in the optical path by means of the coordinated configuration of the beam splitter prism 140 and the first lens 210, which effectively improves the structural stability and system robustness of the lidar and significantly reduces the risk of inaccuracy during long-term use.

[0103] In some embodiments, the light emitting component 110 includes a two-dimensional array laser. The light receiving component 120 includes a two-dimensional array detector. For example, the light emitting component 110 includes a matrix-arranged VCESL array. The light receiving component 120 includes a two-dimensional array of SPADs. The emission field of view of the VCESL array corresponds to the receiving field of view of the SPAD array. The VCESL array can emit probe light L1 into the field of view of the lidar. The SPAD array can receive the echo light L2 reflected by the object from the probe light L1 within the field of view. VCESLs at different positions can emit probe light L1 into different field angles within the field of view. SPADs at different positions can receive the echo light L2 from different field angles within the field of view.

[0104] For example, one or more VCSELs can function as a transmitter. A VCSEL array includes multiple transmitters. These transmitters are arranged in a two-dimensional array. One or more SPADs can function as a receiver. A SPAD array includes multiple receivers. These receivers are arranged in a two-dimensional array. The transmitters and receivers have a preset field-of-view correspondence, such as one-to-many, one-to-one, many-to-one, or many-to-many. The transmitter emits a probe light L1 towards a field of view. The corresponding receiver receives the echo light L2 reflected from that field of view. The transmitters and receivers of the two-dimensional array enable detection within the two-dimensional field of view range of a lidar system.

[0105] In some embodiments, the transmitters and receivers of the two-dimensional array can operate in parallel or in a round-robin fashion according to a preset timing sequence. Round-robin operation can include one transmitter and one receiver operating in a single timing sequence, or it can include multiple transmitters and multiple receivers operating in parallel in a single timing sequence.

[0106] In some embodiments, the imaging component 130 includes a two-dimensional array image sensor. For example, the imaging component 130 includes a matrix-arranged CMOS array. The imaging field of view of the CMOS array corresponds to the receiving field of view of the SPAD array. The size of the imaging field of view can be greater than, less than, or equal to the size of the receiving field of view. The CMOS array can determine the image information of the two-dimensional imaging field of view of the lidar. The lidar can determine fused data of depth information and image information based on the correspondence between the fields of view of the CMOS array and the SPAD array.

[0107] In some embodiments, the optical emitting component 110 may further include a matrix-arranged EEL array, DFB array, optical output port array, or other types of laser array. The optical receiving component 120 may further include a two-dimensionally arranged SiPM array, APD array, PD array, or other types of detector array.

[0108] In some embodiments, the lidar also includes a mounting component (not shown). The mounting component can be used to securely mount one or more of the beam splitter 140, the light emitting component 110, the light receiving component 120, and the imaging component 130. For example, the beam splitter 140, the light emitting component 110, the light receiving component 120, and the imaging component 130 are fixedly mounted relative to the mounting component, which is beneficial to the structural stability of the lidar during operation.

[0109] In some embodiments, the lidar further includes a third lens (not shown). The third lens can be disposed between the beam splitter prism 140 and the light receiving assembly 120. The lidar's receiving lens includes both the third lens and the first lens 210, which can increase the lidar's receiving focal length. This allows for the use of a larger photodetector array in the light receiving assembly 120, increasing the receiving aperture and improving the lidar's range and signal-to-noise ratio.

[0110] In some embodiments of this disclosure, such as Figure 11 As shown, the lidar also includes a filter 160. The filter 160 is disposed between the first wavelength beam splitter S2 and the light receiving component 120.

[0111] The filter 160 can suppress stray light such as ambient light from entering the optical receiver 120, thereby improving the signal-to-noise ratio of the lidar.

[0112] In some embodiments, such as Figure 11 As shown, the filter 160 is disposed on the surface of the beam splitter 140 near the light receiving component 120.

[0113] Figure 11 The filter 160 shown is only a schematic structure, and its specific position is not fixed. In practical applications, the position of the filter 160 can be set according to requirements to meet different optical layouts and functional requirements. For example, the filter 160 can be set independently of the beam splitter 140 and located between the first wavelength beam splitting surface S2 and the light receiving component 120.

[0114] In some embodiments of this disclosure, the optical emitting assembly 110 includes a polarized laser. The lidar also includes a phase modulator 170. The phase modulator 170 can modulate the phase of the probe light L1 and the echo light L2. The phase modulator 170 is disposed downstream of the optical path of the polarization beam splitter S1 along the optical path of the probe light L1.

[0115] In some embodiments, such as Figure 11 As shown, a phase modulator 170 is disposed on the surface of the beam splitter 140. This surface is the surface of the beam splitter 140 facing the first lens 210. In some embodiments, the phase modulator 170 includes a quarter-wave plate.

[0116] Figure 11 The phase modulator 170 shown is only a schematic structure, and its specific position is not fixed. In practical applications, the position of the phase modulator 170 can be set according to requirements to meet different optical layouts and functional requirements. For example, the phase modulator 170 can be set independently of the beam splitter 140 and located between the first lens 210 and the beam splitter 140, or it can be set on the emitting surface of the scanner 310, or it can be set on the surface of the light separating element 410.

[0117] In some embodiments, the probe light L1 has a first polarization state when it is transmitted to the polarization beam splitter S1. The echo light L2 has a second polarization state when it is transmitted to the polarization beam splitter S1.

[0118] The polarization direction of the first polarization state is different from that of the second polarization state. The probe light L1 and the echo light L2 can be separated when they are transmitted to the polarization splitter S1.

[0119] In some embodiments, the polarization direction of the first polarization state is perpendicular to the polarization direction of the second polarization state. For example, the first polarization state is P-polarization and the second polarization state is S-polarization, or the first polarization state is S-polarization and the second polarization state is P-polarization.

[0120] The phase modulator 170 modulates the phase of the probe light L1 and the echo light L2, so that the polarization direction of the first polarization state is different from that of the second polarization state.

[0121] The following explanation uses a P-polarized laser and a quarter-wave plate as an example to illustrate the change in polarization direction of the probe light L1 and the echo light L2.

[0122] The probe light L1 is p-polarized before reaching the phase modulator 170. Its polarization direction in the first polarization state is p-polarized. When the probe light L1 reaches the phase modulator 170, its polarization direction changes from p-polarized to elliptically polarized. The echo light L2 is elliptically polarized before reaching the phase modulator 170. Its polarization direction changes from elliptically polarized to s-polarized when it reaches the phase modulator 170. Its polarization direction in the second polarization state is s-polarized.

[0123] It should be noted that the above example illustrates the change in polarization direction of the probe light L1 and the echo light L2. The specific polarization directions of the first and second polarization states are not limited to those in the example. In practical applications, the polarization directions can be adjusted according to system design requirements, as long as the polarization direction of the first polarization state remains perpendicular to the polarization direction of the second polarization state.

[0124] In some embodiments, the laser is an unpolarized laser. For example... Figure 11As shown, the lidar also includes a linear polarizer 180. The linear polarizer 180 is disposed between the light emitting assembly 110 and the beam splitter 140. The linear polarizer 180 is used to convert the unpolarized probe light L1 output from the unpolarized laser into probe light L1 with a specific polarization direction (such as P-polarization).

[0125] Figure 11 The linear polarizer 180 shown is only a schematic structure, and its position is not fixed. In practical applications, the position of the linear polarizer 180 can be set according to requirements to meet different optical layouts and functional requirements. For example, the linear polarizer 180 can be disposed on the surface of the beam splitter 140 near the light emitting component 110.

[0126] In some embodiments of this disclosure, such as Figure 11 As shown, the lidar also includes a first antireflection coating 191. The first antireflection coating 191 is disposed on the surface of the beam splitter 140 near the light emitting component 110. The first antireflection coating 191 can reduce the reflection loss of the probe light L1 on the surface of the beam splitter 140 near the light emitting component 110.

[0127] In some embodiments of this disclosure, such as Figure 11 As shown, the lidar also includes a second anti-reflection coating 192. The second anti-reflection coating 192 is disposed on the surface of the beam splitter 140 near the imaging component 130. The second anti-reflection coating 192 can reduce the reflection loss of ambient light L3 on the surface of the beam splitter 140 near the imaging component 130.

[0128] In some embodiments of this disclosure, such as Figure 11 As shown, the lidar also includes a first antireflective coating 191 and a second antireflective coating 192.

[0129] Figure 12 This is a schematic diagram of the structure of a lidar provided in some embodiments of this disclosure.

[0130] In some embodiments of this disclosure, such as Figure 12 As shown, the lidar includes a light emitting component 110, a light receiving component 120, an imaging component 130, a beam splitter 140, and a first lens 210. The light emitting component 110, light receiving component 120, imaging component 130, beam splitter 140, or first lens 210 may be the same as or similar to the light emitting component 110, light receiving component 120, imaging component 130, beam splitter 140, or first lens 210 in the aforementioned embodiments. Exemplarily, the lidar also includes a scanner 310. The scanner 310 can deflect and transmit the probe light L1.

[0131] The scanner 310 may include a rotating mirror or a tilting mirror. The scanner 310 can transmit the probe light L1 to the field of view (FOV1) of the lidar, enabling scanning of one or more directions within the FOV1. For example, FOV1 corresponds to the emission field of view of the light emitting assembly 110 and the receiving field of view of the light receiving assembly 120. This disclosure does not limit the implementation of the scanner 310. Exemplarily, the rotation axis of the scanner 310 is parallel to the vertical direction of the lidar. Rotating or tilting the scanner 310 around the rotation axis allows the FOV1 of the lidar to be scanned horizontally. The scanner 310 can increase the horizontal field of view range of the lidar.

[0132] In some embodiments of this disclosure, such as Figure 12 As shown, the lidar also includes a light splitter element 410. The light splitter element 410 is located in the optical path of the probe light L1, positioned between the first lens 210 and the scanner 310. The light splitter element 410 can transmit the probe light L1 to the scanner 310. The light splitter element 410 can also transmit the echo light L2 transmitted from the scanner 310 to the first lens 210.

[0133] like Figure 12 As shown, the light-splitting element 410 is used to reflect the probe light L1 and the echo light L2, and transmit the ambient light L3. The ambient light L3 transmitted from the imaging field of view (FOV2) of the lidar can be transmitted through the light-splitting element 410 to the first lens 210. The sizes of FOV1 and FOV2 can be the same or different.

[0134] Figure 12 The reflection and transmission characteristics of the light-splitting element 410 shown are schematic. In practical applications, the reflection and transmission characteristics of the light-splitting element 410 can be configured according to requirements to meet different optical layouts and functional requirements. For example, the light-splitting element 410 is used to transmit the probe light L1 and the echo light L2, and reflect the ambient light L3.

[0135] In some embodiments, the light emitting component 110 includes a one-dimensional array laser. Alternatively, the light emitting component includes a two-dimensional array laser. The aspect ratio of the two-dimensional array is large. For example, the aspect ratio of the two-dimensional array is greater than 5. Exemplarily, the rotation axis of the scanner 310 is parallel to the vertical direction of the lidar. The arrangement direction of the one-dimensional array laser, or the length direction of the two-dimensional array laser, can be parallel to the rotation axis of the scanner 310, or the angle between it and the rotation axis of the scanner 310 is small. For example, the angle is not greater than 10°. Or, for example, the angle is not greater than 5°. Lasers at different positions in the vertical direction can emit the probe light L1 to different angles in the vertical direction of the lidar, thereby achieving scanning of the vertical field of view range of the laser.

[0136] In some embodiments, the light emitting component 110 may include a one-dimensional or two-dimensional array of VCSELs, EELs, DFBs, light output ports, or other types of laser arrays.

[0137] In some embodiments, the light receiving component 120 includes a one-dimensional array detector. Alternatively, the light receiving component 120 includes a two-dimensional array detector. The aspect ratio of the two-dimensional array is large. For example, the aspect ratio of the two-dimensional array is greater than 2. Or, the aspect ratio of the two-dimensional array is greater than 3. For example, the light receiving component 120 includes a two-dimensional SPAD array. SPADs at different positions can receive echo light L2 from different field angles within the field of view.

[0138] The optical receiving component 120 may also include a two-dimensional SiPM array, APD array, PD array or other types of detector array.

[0139] In some embodiments, the imaging component 130 includes a two-dimensional array image sensor. For example, the imaging component 130 includes a matrix-arranged CMOS array. The imaging field of view of the CMOS array and the receiving field of view of the SPAD array have a preset relative relationship. The size of the imaging field of view can be greater than, less than, or equal to the size of the receiving field of view. The CMOS array can determine the image information of the two-dimensional imaging field of view of the lidar. The lidar can determine fused data of depth information and image information based on the relative relationship of the fields of view of the CMOS array and the SPAD array.

[0140] In some embodiments of this disclosure, such as Figure 13 As shown, the light splitter element 410 includes a second wavelength beam splitter 411. The second wavelength beam splitter 411 is used to reflect the probe light L1 and the echo light L2, and transmit the ambient light L3. Exemplarily, when the probe light L1 is incident on the light splitter element 410 through the first lens 210, the second wavelength beam splitter 411 reflects the probe light L1 onto the scanner 310. When the echo light L2 is incident on the light splitter element 410 through the scanner 310, the second wavelength beam splitter 411 reflects the echo light L2 back to the first lens 210. The second wavelength beam splitter 411 transmits the ambient light L3 to the first lens 210.

[0141] In some embodiments of this disclosure, such as Figure 14As shown, the light-splitting element 410 includes a reflective surface 412 and a light-transmitting surface 413 located on at least one side of the reflective surface 412. The reflective surface 412 is used to reflect the probe light L1 and the echo light L2. The light-transmitting surface 413 is used to transmit ambient light L3. Exemplarily, when the probe light L1 is incident on the light-splitting element 410 through the first lens 210, the reflective surface 412 reflects the probe light L1 onto the scanner 310. When the echo light L2 is incident on the light-splitting element 410 through the scanner 310, the reflective surface 412 reflects the echo light L2 onto the first lens 210. The light-transmitting surface 413 transmits the ambient light L3 into the first lens 210.

[0142] In some embodiments of this disclosure, such as Figure 15 As shown, the light-splitting element 410 includes a reflective portion 412 and a light-transmitting portion 414 located on the reflective portion 412. The reflective portion 412 is used to reflect the probe light L1 and the echo light L2. The light-transmitting portion 414 is used to transmit ambient light L3. The light-transmitting portion 414 may include a light-transmitting medium, such as glass or plastic. The light-transmitting portion 414 may also be a through hole. The reflective surface of the reflective portion 412 may be annular, rectangular, or irregular in shape. The light-transmitting portion 414 may be located at the geometric center of the reflective portion 412 or may be offset from the geometric center of the reflective portion 412. For example, when the probe light L1 is incident on the light-splitting element 410 through the first lens 210, the reflective portion 412 reflects the probe light L1 onto the scanner 310. When the echo light L2 is incident on the light-splitting element 410 through the scanner 310, the reflective portion 412 reflects the echo light L2 onto the first lens 210. The light-transmitting part 414 transmits ambient light L3 to the first lens 210.

[0143] Figure 16 This is a schematic diagram of the structure of a lidar provided in some embodiments of this disclosure.

[0144] like Figure 16 As shown, the lidar includes a light emitting component 110, a light receiving component 120, an imaging component 130, a beam splitter 140, and a first lens 210. The light emitting component 110, light receiving component 120, imaging component 130, beam splitter 140, or first lens 210 can be the same as or similar to the light emitting component 110, light receiving component 120, imaging component 130, beam splitter 140, or first lens 210 in the aforementioned embodiments. Exemplarily, the lidar also includes a second lens 220. The second lens 220 is disposed between the light emitting component 110 and the beam splitter 140, located in the optical path of the detection light L1. The lidar's emitting lens, including the second lens 220 and the first lens 210, can increase the lidar's emitting focal length. This improves the lidar's range-finding capability.

[0145] In some embodiments, the surfaces of the light emitting component 110 and the light receiving component 120 may have an included angle. The included angle can be any value from 0 to 90°. For example, the included angle is 90° or approximately 90°. The optical path of the probe light L1 emitted by the light emitting component 110 is perpendicular or approximately perpendicular to the optical path of the echo light L2 incident on the light receiving component 120.

[0146] For example, the included angle is 0° or approximately 0°. Figure 16 As shown, the light emitting component 110 and the light receiving component 120 are arranged in parallel. The lidar also includes a reflector 230. The reflective surface of the reflector 230 can form a 45° angle with the surfaces of the light emitting component 110 and the light receiving component 120. The optical path of the probe light L1 emitted by the light emitting component 110 after being reflected by the reflector 230 is perpendicular or approximately perpendicular to the optical path of the echo light L2 incident on the light receiving component 120.

[0147] In some embodiments, the lidar also includes one or more of a scanner 310 and a light splitter 410. The scanner 310 and the light splitter 410 may be the same as or similar to the scanner 310 and the light splitter 410 in the foregoing embodiments.

[0148] In some embodiments, the reflective surface of the light splitter element 410 or the scanner 310 includes a phase retardation film. The phase retardation film can be deposited on the reflective surface of the scanner or the light splitter element. In this way, the number of optical components in the lidar can be reduced.

[0149] In some embodiments, the lidar further includes a phase modulator 170. The phase modulator 170 is the same as or similar to the phase modulator in the foregoing embodiments.

[0150] In some embodiments, the lidar further includes one or more of a filter 160, a linear polarizer 180, a first antireflective coating 191, and a second antireflective coating 192. The filter 160, the linear polarizer 180, the first antireflective coating 191, or the second antireflective coating 192 are the same as or similar to the filter 160, the linear polarizer 180, the first antireflective coating 191, or the second antireflective coating 192 in the foregoing embodiments.

[0151] It should be noted that although several modules of the lidar have been mentioned in the detailed description above, this division is not mandatory. In fact, according to embodiments of this disclosure, the features and functions of two or more modules described above can be implemented in one module. Conversely, the features and functions of one module described above can be further divided and embodied by multiple modules.

[0152] Finally, it should be noted that the above are merely preferred embodiments of this disclosure and are not intended to limit this disclosure. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A lidar, characterized in that, include: Optical emitting component, used to emit probe light; A light receiving component is used to receive the echo light formed after the probe light is reflected by the object; Imaging components are used to receive ambient light; as well as A beam splitter includes a polarization beam splitter surface and a first wavelength beam splitter surface; the polarization beam splitter surface is used to separate the probe light and the echo light. The first wavelength beam splitter is used to separate the echo light and the ambient light. The lidar is configured to determine the depth information of the object based on the echo light and to determine image information based on the ambient light. The lidar is also configured to determine fusion information based on the depth information and the image information.

2. The lidar according to claim 1, characterized in that, The polarization beam-splitting surface and the first wavelength beam-splitting surface are disposed on different surfaces of the beam-splitting prism.

3. The lidar according to claim 1, characterized in that, The beam splitter includes four prisms, and the polarization beam splitting surface and the first wavelength beam splitting surface are disposed on the surfaces of the four prisms close to each other; the angle between the polarization beam splitting surface and the first wavelength beam splitting surface is greater than 0°.

4. The lidar according to any one of claims 1 to 3, characterized in that, Also includes: The first lens is located on the optical path of the probe light and is positioned downstream of the optical path of the beam splitter.

5. The lidar according to claim 4, characterized in that, It also includes at least one of the following: The second lens is located in the optical path of the probe light and is positioned between the light emitting component and the beam splitter; or The third lens is located on the optical path of the echo light and is positioned between the light receiving component and the beam splitter.

6. The lidar according to claim 4, characterized in that, Also includes: scanner; The scanner is used to receive the probe light transmitted by the first lens and transmit the probe light to the external field of view.

7. The lidar according to claim 6, characterized in that, Also includes: A light-separating element is located in the optical path of the probe light and is disposed between the first lens and the scanner; The light-splitting element is used to reflect the probe light and the echo light, and transmit the ambient light; or, the light-splitting element is used to transmit the probe light and the echo light, and reflect the ambient light.

8. The lidar according to claim 7, characterized in that, The optical separation element includes a second wavelength beam splitter.

9. The lidar according to claim 7, characterized in that, The light-splitting element includes a reflective surface.

10. The lidar according to any one of claims 1 to 3, characterized in that, It also includes a filter, which is disposed between the first wavelength beam splitter and the light receiving component.

11. The lidar according to claim 10, characterized in that, The filter is disposed on the surface of the beam splitter near the light receiving component.

12. The lidar according to any one of claims 1 to 3, characterized in that, It also includes a phase modulator; the phase modulator is configured to modulate the phase of the probe light and the echo light; the phase modulator is disposed downstream of the optical path of the polarization beam splitter along the optical path of the probe light; The probe light has a first polarization state when it is transmitted to the polarization beam splitter; the echo light has a second polarization state when it is transmitted to the polarization beam splitter, and the polarization direction of the first polarization state is different from the polarization direction of the second polarization state.

13. The lidar according to claim 12, characterized in that, The polarization direction of the first polarization state is perpendicular to the polarization direction of the second polarization state.

14. The lidar according to claim 12, characterized in that, The phase modulator includes a quarter-wave plate.

15. The lidar according to claim 12, characterized in that, The phase modulator is disposed on the surface of the beam splitter.

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