Laser emission module, laser radar and electronic device

Abstract

The application provides a laser emission module, a laser radar and an electronic device, and relates to the technical field of lasers.The laser emission module comprises a laser source and a light-emitting-direction light-uniformizing reflection element.The laser source comprises a plurality of point light sources which are spaced apart along a first direction.In a plane formed by the light-emitting direction of the laser source and the first direction, the front surface and the rear surface of the light-uniformizing reflection element have an included angle, the main optical axis of an initial laser beam and the front surface of the light-uniformizing reflection element have an included angle β, and the included angle β and the included angle θ are in two non-parallel planes.The initial laser beam is reflected by the light-uniformizing reflection element to be emitted as a first laser beam and a second laser beam.The second laser beam is offset in the first direction relative to the first laser beam when emitted.The laser emission module provided by the application can homogenize the initial laser beam emitted by the laser through system optical design without increasing the number of optical elements in the laser emission module.

Description

Technical Field

[0001] This application relates to the field of laser technology, and more specifically, to a laser emitting module, a lidar, and electronic equipment. Background Technology

[0002] With the increasing performance requirements of line-scan lidar designs, especially the improvement in scanning angular resolution, higher collimation is needed for the laser beam emitted by the lidar's transmitting module. Taking the widely used VCSEL (Vertical-Cavity Surface-Emitting Laser) as an example, the collimation of the emitted laser beam is typically improved by reducing the divergence angle of the emitting region. However, reducing the divergence angle affects the design of the laser's output structure, resulting in uneven angular energy distribution in the received spot on the receiving surface. Utility Model Content

[0003] This application provides a laser emitting module, a lidar, and an electronic device that can homogenize the initial laser beam emitted by the laser without increasing the number of optical elements in the laser emitting module through system optical design.

[0004] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows: In one aspect of this application, a laser emitting module is provided, including a laser source and a uniform light reflecting element disposed in the light emission direction of the laser source. The laser source includes a plurality of point light sources, which are spaced apart along a first direction. In the plane formed by the light emission direction of the laser source and the first direction, there is an angle θ between the front surface and the rear surface of the uniform light reflecting element. There is an angle β between the principal optical axis of the initial laser beam and the front surface of the uniform light reflecting element. The angles β and θ are respectively in two non-parallel planes. The initial laser beam is reflected by the uniform light reflecting element and emitted as a first laser beam and a second laser beam. The second laser beam is emitted at a offset in the first direction relative to the first laser beam.

[0005] In another aspect of the embodiments of this application, a lidar is provided, including a laser emitting module of any of the foregoing.

[0006] In another aspect of the embodiments of this application, an electronic device is provided, including any of the aforementioned lidar.

[0007] The beneficial effects of the embodiments of this application include: The laser emitting module provided in this application includes a laser source and a uniform light reflecting element disposed in the light emission direction of the laser source. The laser source includes multiple point light sources, which are spaced apart along a first direction. In the plane formed by the light emission direction of the laser source and the first direction, there is an angle θ between the front surface and the rear surface of the uniform light reflecting element. There is an angle β between the principal optical axis of the initial laser beam and the front surface of the uniform light reflecting element, and the angles β and θ are respectively in two non-parallel planes. The initial laser beam is reflected by the front surface of the uniform light reflecting element and emitted as a first laser beam and a second laser beam. Since there is an angle θ between the front and rear surfaces of the homogenizing reflector in the plane formed by the laser source's output direction and the first direction, and an angle β between the principal axis of the initial laser beam and the front surface of the homogenizing reflector, and since angles θ and β are in two non-parallel planes, the directions of reflection of the first and second laser beams emitted after reflection from the front surface of the homogenizing reflector are also different. The emitted second laser beam is offset from the first laser beam in the first direction. Therefore, by adjusting the parameters of the laser source and the homogenizing reflector, the output directions of the first and second laser beams can be set, so that the first and second laser beams can achieve connection between the light spots, partial overlap of the light spots, or mutual separation of the light spots on the receiving surface after emission, thereby achieving light spot homogenization. Attached Figure Description

[0008] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1 This is one of the optical path diagrams of the laser emitting module provided in the embodiments of this application; Figure 2 A schematic diagram illustrating the light-uniformation principle of the light-uniformation reflecting element in the laser emitting module provided in this application embodiment; Figure 3 This is a schematic diagram of the structure of the uniform light reflecting element in the laser emitting module provided in the embodiments of this application; Figure 4 This is one of the schematic diagrams of the uniform beam of the laser emitting module provided in the embodiments of this application; Figure 5 This is the second schematic diagram of the uniform beam distribution of the laser emitting module provided in the embodiments of this application; Figure 6 This is the third schematic diagram of the uniform beam distribution of the laser emitting module provided in the embodiments of this application; Figure 7Fourth schematic diagram of the uniform beam distribution of the laser emitting module provided in the embodiments of this application; Figure 8 Fifth schematic diagram of the uniform beam distribution of the laser emitting module provided in the embodiments of this application; Figure 9 This is the sixth schematic diagram of the uniform beam distribution of the laser emitting module provided in the embodiments of this application; Figure 10 One of the intensity distribution curves of the laser beam emitted by the laser emitting module provided in this application embodiment is shown on the receiving surface. Figure 11 A comparison diagram of the spot state of the laser beam emitted by the laser emitting module provided in the embodiment of this application at the receiving surface; Figure 12 This is the second schematic diagram of the optical path of the laser emitting module provided in the embodiments of this application; Figure 13 for Figure 12 One of the comparison images of the beam uniformity state of the laser emission module; Figure 14 for Figure 12 One of the comparison diagrams of the light intensity curves of the emitted light spot of the laser emitting module; Figure 15 This is the third schematic diagram of the optical path of the laser emitting module provided in the embodiments of this application; Figure 16 for Figure 15 One of the comparison images of the beam uniformity state of the laser emission module; Figure 17 for Figure 15 The second comparison of the uniformity of the laser emission module's spot size; Figure 18 Fourth of the optical path diagrams of the laser emitting module provided in the embodiments of this application; Figure 19 for Figure 18 Comparison of the beam uniformity state of the laser emission module; Figure 20 Fifth of the optical path diagrams of the laser emitting module provided in the embodiments of this application; Figure 21 for Figure 20 Comparison of the beam uniformity state of the laser emission module; Figure 22 The second comparison diagram of the light intensity curve of the emitted light spot of the laser emitting module provided in the embodiments of this application; Figure 23 This is one of the optical path diagrams of a lidar provided in the embodiments of this application; Figure 24 This is the second schematic diagram of the optical path of the lidar provided in the embodiments of this application; Figure 25 The third schematic diagram of the optical path of the lidar provided in the embodiments of this application; Figure 26 The fourth schematic diagram of the optical path of the lidar provided in the embodiments of this application.

[0010] Icons: 10-Laser source; 101-Point source; 11-First polarized beam; 12-Second polarized beam; 20-Optical lens group; 30-Uniform light reflecting element; 301-Transparent optical medium; 302-Polarizing film layer; 303-Reflective film layer; 31-Front surface; 32-Rear surface; 41-First laser beam; 42-Second laser beam; 50-Polarizing optical element; 60-Receiving module; 70-Scanning module. Detailed Implementation

[0011] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. It should be noted that, in the absence of conflict, the various features in the embodiments of this application can be combined with each other, and the combined embodiments are still within the protection scope of this application.

[0012] In the description of this application, it should be noted that the terms "upper," "lower," "left," "right," "inner," and "outer," etc., 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 therefore should not be construed as limiting this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0013] In the selection of light sources for lidar, VCSELs (Vertical-Cavity Surface-Emitting Lasers) are currently widely used. The initial laser beam emitted by a VCSEL must meet the high collimation requirements of the lidar light source. Given the limited size of the emission module design, this usually has to be achieved by reducing the width of the emitting area.

[0014] Due to current VCSEL manufacturing limitations, VCSELs with narrow emission areas can only be designed as discrete single-aperture lasers. In a laser consisting of discrete single apertures, the laser beam exits through each individual aperture, leaving no laser emission in the gaps between apertures. This results in an uneven angular energy distribution in the received spot of the entire laser beam emitted by the VCSEL. Since lidar typically requires a long distance for ranging, this uneven angular energy distribution is further amplified over longer distances, significantly impacting lidar ranging performance. Therefore, it is necessary to consider homogenizing and modulating the laser beam emitted from the VCSEL before using it for ranging in lidar applications.

[0015] The current mainstream method for homogenizing light involves placing a homogenizing mirror (typically a diffuser with a microlens array, which is difficult to design and expensive) on the output side of the VCSEL to homogenize and modulate the emitted laser beam. However, adding a homogenizing mirror to the transmitting module not only increases the size of the transmitting module but also increases the manufacturing cost of the transmitting module and the lidar using it.

[0016] Based on this, one aspect of the embodiments of this application provides a laser emitting module, such as... Figure 1 As shown in the middle left figure, the laser emitting module includes a laser source 10 and a uniform light reflecting element 30 disposed in the light emission direction of the laser source 10, as follows: Figure 2 As shown in the left figure, there is an angle β between the principal optical axis of the initial laser beam and the front surface 31 of the uniform light reflecting element 30, and the angle β and the angle θ are in two non-parallel planes respectively. The initial laser beam is reflected by the uniform light reflecting element 30 and emitted as the first laser beam 41 and the second laser beam 42. According to Figure 1 In the coordinate system shown in the left figure, the laser source 10 includes multiple point light sources 101 ( Figure 1 (Not shown in the image) The first direction of the arrangement is the Y-axis direction. The uniform light reflecting element 30 is positioned in the plane containing the Z and X axes. Please refer to... Figure 2 As shown in the left figure, the uniform light reflecting element 30 can be configured to have an angle between the front surface 31 and the rear surface 32 in the plane formed by the first direction and the direction of the laser emitted from the laser source 10 (i.e., in the YZ plane), similar to a wedge structure.

[0017] When the initial laser beam is directed toward the uniform light reflecting element 30, which forms an angle θ between the front surface 31 and the rear surface 32... Figure 2 As can be seen in the left figure, the first laser beam 41 and the second laser beam 42 emitted are in different directions due to the different angles of their respective reflecting surfaces. That is, the light spot emitted by the first laser beam 41 is ( Figure 2Using the circle filled with vertical stripes in the right figure as a reference, the second laser beam 42 is deflected and emitted in the first direction, which is... Figure 2 The circle filled with diagonal stripes in the right image, from Figure 2 As can be seen from the receiving surface of the YZ plane in the right figure, the outlines of the first laser beam 41 and the second laser beam 42 do not completely overlap. Incomplete overlap includes partial overlap, adjacent light spots connecting, or adjacent but not connected, which makes the energy distribution of the emitted laser similar. This can make the distance between each detection point within the detection field of view close, and can also increase the number of laser emission lines and improve the detection resolution.

[0018] Of course, the specific settings for the pointing angle of the first laser beam 41, the pointing angle of the second laser beam 42, and the size of the angle between them can be made by setting the angle of the uniform light reflecting element 30 in the optical path and the angles of the front surface 31 and the rear surface 32 of the uniform light reflecting element 30 respectively.

[0019] In addition, it should be noted that, in Figure 2 The uniform light reflecting element 30 shown in the left figure is... Figure 1 The left figure shows a schematic diagram from another perspective based on the uniform light reflecting element 30, and Figure 1 Left image and Figure 1 Right image, Figure 2 Left image and Figure 2 The images on the right show different perspectives, specifically through... Figure 1 and Figure 2 As can be seen from the coordinate diagram. When the laser beam emitted by the laser emitting module of this application needs to be homogenized in intensity in other directions, it can also be adjusted by adding a homogenizing reflective element 30 with an included angle θ between the front surface 31 and the rear surface 32 in other directions of interest, which will not be described in detail here.

[0020] It should be noted that in the laser emitting module of this application embodiment, there is no strict limitation on the parameters used to select the initial laser beam so that a portion of the initial laser beam is reflected out by the front surface 31 of the uniform light reflecting element 30 and a portion is reflected out by the rear surface of the uniform light reflecting element 30. For example, wavelength selection can be used to make the first laser beam 41 and the second laser beam 42 after the initial laser beam is reflected out by the uniform light reflecting element have an angle in the first direction, that is, the emitted second laser beam 42 is offset from the first laser beam 41 in the first direction. Alternatively, other methods can be used to divide the initial laser beam, as long as it can be divided into two beams (the first laser beam 41 and the second laser beam 42) with an angle in the first direction after being reflected out by the uniform light reflecting element 30, so that the first laser beam 41 and the second laser beam 42 can be adjusted according to the parameter settings of the optical elements such as the uniform light reflecting element 30 to achieve the connection, partial overlap or separation of the light spots on the receiving surface, thereby achieving the uniformity of the light spots.

[0021] The laser emitting module provided in this application embodiment includes a laser source 10 and a uniform light reflecting element 30 in the light emission direction of the laser source 10. The laser source 10 includes a plurality of point light sources 101, which are arranged at intervals along a first direction. In the plane formed by the light emission direction of the laser source 10 and the first direction, there is an angle θ between the front surface 31 and the rear surface 32 of the uniform light reflecting element 30. The principal optical axis of the initial laser beam has an angle β with the front surface 31 of the uniform light reflecting element 30, and the angles β and θ are respectively in two non-parallel planes. The initial laser beam is reflected by the front surface 31 of the uniform light reflecting element 30 and emitted as a first laser beam 41 and a second laser beam 42. Since in the plane formed by the light emission direction of the laser source 10 and the first direction (i.e. Figure 2 As shown in the YZ plane, there is an angle θ between the front surface 31 and the rear surface 32 of the uniform light reflecting element 30, and an angle β between the principal axis of the initial laser beam and the front surface 31 of the uniform light reflecting element 30. Since angles θ and β lie in two non-parallel planes, the directions of the first and second laser beams reflected from the front surface of the uniform light reflecting element are also different. Figure 2 As shown in the figure, the emitted first laser beam 41 and the second laser beam 42 are emitted in the directions indicated by the red arrows and green arrows, respectively. The outlines of the light spots received by the emitted first laser beam 41 and the second laser beam 42 on the receiving surface will not completely overlap. Therefore, by adjusting the parameters of the laser source 10 and the parameters of the uniform light reflecting element 30, the emission directions of the first laser beam 41 and the second laser beam 42 can be selected and designed. This allows the light spots of the first laser beam 41 and the second laser beam 42 to be connected, partially overlapped, or separated on the receiving surface after emission, thereby achieving uniformity of the light spots.

[0022] In one feasible implementation, please refer to Figure 1 and Figure 2 As shown, the initial laser beam emitted from the laser source includes a first polarized beam 11 and a second polarized beam 12. The polarization direction of the first polarized beam 11 is perpendicular to the polarization direction of the second polarized beam 12. The first polarized beam 11 is reflected by the front surface 31 of the homogenizing reflector 30 and emitted as the first laser beam 41. The second polarized beam 12 passes through the front surface 31, enters the homogenizing reflector 30, and is reflected by the rear surface 32 and emitted as the second laser beam 42. That is, the initial laser beam is divided into the first polarized beam 11 and the second polarized beam 12 by polarization selection. Hereinafter, this polarization selection method will be used for further explanation.

[0023] like Figure 1 As shown in the left figure, the initial laser beam is emitted from the output port of the laser source 10 along the output direction. When the divergence angle of the initial laser beam emitted by the laser source 10 is small enough, such as within 10°, the initial laser beam can be directly incident on the homogenizing reflector 30 for homogenization. The initial laser beam is considered as a whole laser beam, which includes a first polarized beam 11 and a second polarized beam 12. The polarization directions of the first polarized beam 11 and the second polarized beam 12 are perpendicular to each other. The homogenizing reflector 30 includes a front surface 31 and a rear surface 32 with an included angle, wherein the reference... Figure 2 As shown in the left figure, the angle between the front surface 31 and the rear surface 32 of the homogenizing reflector 30 is directly visible in the cross-section on the YZ plane. The homogenizing reflector 30 is used to reflect the initial laser beam so that the initial laser beam is reflected and emitted after the reflective surface changes direction. Specifically, the front surface 31 of the homogenizing reflector 30 can selectively reflect either the first polarized beam 11 or the second polarized beam 12.

[0024] For example, such as Figure 1 As shown in the left figure, the front surface 31 of the uniform light reflecting element 30 directly reflects the first polarized beam 11. That is, the first polarized beam 11 in the initial laser beam is reflected off the front surface 31 of the uniform light reflecting element 30 because its polarization direction is perpendicular to the transmission axis of the front surface 31 of the uniform light reflecting element 30. The uniform light reflecting element 30 and the principal optical axis ( Figure 1In the left figure, the black arrow represents the schematic direction of the initial laser beam incident on the homogenizing reflector 30. An angle β is formed between the initial laser beam and the front surface 31 of the homogenizing reflector 30, meaning the initial laser beam is incident at angle β. For example, when the angle β between the homogenizing reflector 30 and the principal optical axis is 45°, the first polarized beam 11 is incident on the front surface 31 of the homogenizing reflector 30 at a 45° angle and exits at a 90° angle from its incident position on the front surface 31. The second polarized beam 12 in the initial laser beam is also incident on the front surface 31 of the homogenizing reflector 30 at a 45° angle, but it passes through the front surface 31 and enters the interior of the homogenizing reflector 30, reaching the rear surface 32 of the homogenizing reflector 30 for reflection. The reflected second polarized beam 12 then passes through the front surface 31 again before exiting.

[0025] However, since the homogenizing reflector 30 is a solid optical element, it must have its own thickness. Because the optical path length of the second polarized beam 12 is different from that of the first polarized beam 11, the position where the second polarized beam 12 exits from the front surface 31 after reflection is no longer the incident position when the initial laser beam entered the front surface 31 of the homogenizing reflector 30. For example... Figure 1 As shown in the left figure, there is a certain offset between the two in the Z-axis direction. Therefore, when the initial laser beam exits through the homogenizing reflector 30, the first laser beam 41 emitted from the first polarized beam 11 and the second laser beam 42 emitted from the second polarized beam 12 do not overlap. Consequently, the light spots of the first laser beam 41 and the second laser beam 42 received on the receiving surface will not completely overlap. Figure 1 As shown in the right figure, the light spots are arranged at a certain distance based on the thickness of the uniform light reflecting element 30. When the laser source 10 includes multiple point light sources 101 arranged along the Y-axis, the light spots of the two columns of the first laser beam 41 and the second laser beam 42 received on the receiving surface are... Figure 1 The diagram on the right shows a schematic of the YZ plane.

[0026] For example, when the laser emitting module of this application embodiment is used in lidar, such as Figure 7 As shown, the laser source 10 includes multiple point light sources 101 arranged along the Y-axis. By adding a second laser beam 42 that is offset from the first laser beam 41 and interlaced in the Y-axis direction between the detection light spots emitted by adjacent point light sources 101, the angular energy distribution of the emitted laser light spots can be achieved.

[0027] It should be noted that, in this embodiment, the initial laser beam emitted from the laser source 10 includes a first polarized beam 11 and a second polarized beam 12 with mutually perpendicular polarization directions. These can be P-beams and S-beams, for example, the first polarized beam 11 is an S-beam and the second polarized beam 12 is a P-beam (the two can also be interchanged). The following description uses the example of the first polarized beam 11 being an S-beam and the second polarized beam 12 being a P-beam. The ratio of P-beams to S-beams in the initial laser beam is not specifically limited in this embodiment. If it is necessary to limit the ratio of P-beams to S-beams, it can be adjusted by adjusting the parameters of the laser source 10, or it can be adjusted and selected by polarizing optical elements on the light-emitting side of the laser source 10. In this embodiment, the following description uses 50% each for P-beams and S-beams.

[0028] Furthermore, the specific structure of the uniform light reflecting element 30 is not limited in the embodiments of this application. As long as the polarization of the incident initial laser beam can be selected so that polarized light with mutually perpendicular polarization directions is reflected out through the front surface 31 and the rear surface 32 respectively.

[0029] In one feasible implementation, such as Figure 3 As shown, the uniform light reflecting element 30 includes a transparent optical medium 301 and a polarizing film layer 302 and a reflective film layer 303 respectively deposited on two opposite surfaces of the transparent optical medium 301. The transmission axis of the polarizing film layer 302 is perpendicular to the vibration direction of the first polarized light beam 11, that is, the polarizing film layer 302 reflects the first polarized light beam 11 and transmits the second polarized light beam 12. The surface on which the polarizing film layer 302 is deposited is the front surface 31, and the surface on which the reflective film layer 303 is deposited is the rear surface 32.

[0030] It should be noted that in some special cases or specific application scenarios, for example, if the transparent optical medium 301 is selected as a specific material capable of total internal reflection of the second polarized beam 12, then the reflective film layer 303 may not be deposited on the rear surface 32, and the reflection of the second polarized beam 12 inside the transparent optical medium 301 and its exit from the front surface 31 can be achieved through total internal reflection.

[0031] like Figure 3 As shown, when the laser beam enters the uniform light reflecting element 30, since its interior is a transparent optical medium 301, such as acrylic material or transparent glass, once the beam passes through the front surface 31 and enters the interior of the uniform light reflecting element 30, it can propagate in a straight line without obstruction and with virtually no loss within the uniform light reflecting element 30. It should be noted that the transparency mentioned here refers to the ability of a beam of light with a specific wavelength to pass through the transparent optical medium 301 with as little loss as possible. Considering that beams of different wavelengths may be visible light or non-visible light such as infrared light, this does not refer to the transparency seen by the human eye in a narrow sense.

[0032] Please combine Figure 1 or Figure 2 As shown, a polarizing film layer 302 and a reflective film layer 303 are respectively deposited on two opposite surfaces of the transparent optical medium 301 to form a front surface 31 and a rear surface 32. The transmission axis of the polarizing film layer 302 is perpendicular to the vibration direction of the first polarized beam 11. This allows the initial laser beam containing P-light and S-light to be incident on the uniform light reflecting element 30. The S-light is reflected by the polarizing film layer 302 deposited on one side surface of the transparent optical medium 301, which forms the front surface 31. The transmission axis of the polarizing film layer 302 deposited on the front surface 31 is the same as the polarization direction of the P-light. Therefore, the S-light, whose polarization direction is perpendicular to the transmission axis of the polarizing film layer 302, cannot pass through and is directly reflected out. P-beams are emitted from the polarization film layer 302 on the front surface 31 and enter the transparent optical medium 301. They propagate almost undamaged through the transparent optical medium 301 to the reflective film layer 303 on the rear surface 32. After being reflected by the reflective film layer 303 on the rear surface 32, P-beams pass through the transparent optical medium 301 and are emitted through the polarization film layer 302 on the front surface 31.

[0033] In one feasible implementation, the initial laser beam emitted by the laser source 10 typically has a large divergence angle, making it difficult to meet the collimation requirements of applications such as lidar. Therefore, the initial laser beam needs to be collimated and modulated by the optical lens group 20 to ensure it meets the collimation requirements of lidar scanning. Alternatively, in other applications, optical elements may be included to modulate other required parameters of the initial laser beam, ensuring that the initial laser beam passing through the optical lens group 20 meets these modulation parameter requirements.

[0034] The following examples use a laser emitting module with optical lens group 20 as a specific illustration.

[0035] In one feasible implementation, the angle between the first laser beam 41 and the second laser beam 42 emitted from the same point light source 101 via the uniform light reflecting element 30 is (N+1 / 2)α, where α is the optical axis angle corresponding to the center distance between the emitted light spots of the two adjacent point light sources 101.

[0036] Reference Figure 2 As shown in the left figure, the angle between the first laser beam 41 and the second laser beam 42 emitted from the same point light source 101 through the uniform light reflecting element 30 is ( Figure 2 When the angle between the extended dashed lines in the left figure is (N+1 / 2)α, the peak and valley values ​​of the P and S light intensities are just right to achieve the connection between the light spots, realize energy complementarity, and achieve the best effect of light spot homogenization.

[0037] In one feasible implementation, such as Figure 2 As shown, the angle θ between the front surface 31 and the rear surface 32 of the uniform light reflecting element 30 is ≤ 5°. For example, the angle θ between the front surface 31 and the rear surface 32 of the uniform light reflecting element 30 satisfies: 0 < θ ≤ 1.5°. Through the angle θ between the front surface 31 and the rear surface 32 of the uniform light reflecting element 30, the laser beam transmitted through the uniform light reflecting element 30 is received on the receiving surface as a uniform light spot in the Y direction, thereby improving the problem of uneven energy distribution of the received light spot in the Y direction caused by the spacing between the point light sources 101.

[0038] Still refer to Figure 2 As shown, the purpose of using the homogenizing reflector 30 to redirect the initial laser beam and adjust the different emission directions of the S-beam and P-beam is to homogenize the light intensity of the light spot on the receiving surface. Therefore, if the angle θ between the front surface 31 and the rear surface 32 is too large, the distance between the light spot positions of the emitted first laser beam 41 and the second laser beam 42 on the receiving surface will be large, making it impossible to connect them and thus difficult to achieve the best light spot homogenization effect. Therefore, under normal circumstances, the angle θ between the front surface 31 and the rear surface 32 of the homogenizing reflector 30 is ≤ 5°. More preferably, the angle θ between the front surface 31 and the rear surface 32 of the homogenizing reflector 30 satisfies: 0 < θ ≤ 1.5°, then the connection and homogenization effect between the light spots is better.

[0039] In one feasible implementation, such as Figure 1 As shown, the distance T between the front surface 31 and the rear surface 32 of the uniform light reflecting element 30 is less than or equal to 20 mm. For example, the distance T between the front surface 31 and the rear surface 32 of the uniform light reflecting element 30 is between 0.5 mm and 5 mm. By controlling the distance T between the front surface 31 and the rear surface 32, it is avoided that an excessively large distance T would cause excessive separation of the emitted first laser beam 41 and the second laser beam 42 in the Z-axis direction, resulting in unconcentrated light energy and affecting the uniformity of the light spot's light energy.

[0040] like Figure 1 and Figure 2As shown, in the initial laser beam incident on the uniform light reflecting element 30, the S-beam is reflected at the front surface 31, and the P-beam passes through the front surface 31, reaches the rear surface 32, is reflected, and then passes through the front surface 31 again for transmission. Thus, the positions of the first laser beam 41 and the second laser beam 42 exiting from the front surface 31 will shift in the Z-axis direction due to the difference in optical path length. The amount of shift is directly related to the distance T between the front surface 31 and the rear surface 32 of the uniform light reflecting element 30 and the angle of the uniform light reflecting element 30 in the optical path. Furthermore, in the Y-axis direction, there is an included angle θ between the front surface 31 and the rear surface 32 of the uniform light reflecting element 30. Even in a structure where the front surface 31 and the rear surface 32 are parallel, if the distance T between the front surface 31 and the rear surface 32 is too large, it will directly lead to an excessively large distance between the exit positions of the first laser beam 41 and the second laser beam 42 on the front surface. This will also result in an excessively large spot distance between the first laser beam 41 and the second laser beam 42 on the receiving surface, causing the light to be too dispersed and the energy to be unconcentrated, affecting the spot homogenization effect and reducing the ranging capability. Therefore, the distance T between the front surface 31 and the rear surface 32 of the homogenizing reflective element 30 is less than or equal to 20 mm. More preferably, the distance T can be selected between 0.5 mm and 5 mm.

[0041] Of course, the distance T between the front surface 31 and the rear surface 32 of the uniform light reflecting element 30 and the angle θ between the front surface 31 and the rear surface 32 of the uniform light reflecting element 30 in the YZ plane are both relevant parameters that jointly affect the position of the light spot on the receiving surface.

[0042] like Figure 4 As shown, the laser source 10 includes a plurality of point light sources 101 (e.g., six in the figure) arranged at intervals along a first direction. The laser source 10 composed of the plurality of point light sources 101 is a whole collection with a width of L in the first direction and a center distance of d between two adjacent point light sources 101. Normally, the plurality of point light sources 101 are arranged at equal intervals.

[0043] An initial laser beam is emitted jointly from multiple point light sources 101 arranged at intervals of d along the first direction (Y-axis). If there is no homogenizing reflector 30 to homogenize the emitted laser beam, the six initial laser beams will exit after passing through the optical lens group 20 and be received at the receiving surface as... Figure 4 Six equally spaced light spots on the right. From Figure 4 It can be clearly seen that the entire fan-shaped range of the emitted laser beam is equal to the field of view (FOV) of the emitted laser beam. Figure 4 (As shown in the figure), but the six initial laser beams still appear as six discrete light spots within the field of view, and the uniformity of light intensity at various points in such discrete light spots is obviously poor.

[0044] like Figures 5 to 7As shown, for example, the laser emitting module includes a uniform light reflecting element 30. The laser source 10 includes six point light sources 101 spaced apart along the Y-axis. The width of the six point light sources 101 in the Y-axis direction is L, the center distance between two adjacent point light sources 101 is d, and the multiple point light sources 101 are equally spaced. The initial laser beam emitted by the multiple point light sources 101 is collimated by the optical lens group 20 and the uniform light reflecting element 30 is used for beam homogenization. Specifically, the uniform light reflecting element 30 divides the initial laser beam into P-beams and S-beams through polarization selection. Since the front surface 31 and the rear surface 32 of the uniform light reflecting element 30 have an angle θ in the first direction (e.g., ... Figure 6 As shown in the figure, the P-light and S-light emitted by the uniform light reflecting element 30 have different pointing angles, so the positions of the light spots received on the receiving surface are also different.

[0045] like Figure 7 As shown, the circular light spots filled with diagonal lines are the receiving spots for S-beams, and the circular light spots filled with vertical lines are the receiving spots for P-beams. In this way, the receiving spots for P-beams interspersed among the receiving spots for S-beams fill the discrete gaps between the six S-beam receiving spots emitted by the six point light sources 101 on the receiving surface. Please also consider... Figure 5 A schematic diagram of the entire optical path and its connection with Figure 4 By comparison, it is clear that the uniform light reflecting element 30 achieves the uniformization of the light spot on the receiving surface.

[0046] Furthermore, as explained above in the specification, the parameters such as the distance T and the included angle θ between the front surface 31 and the rear surface 32 of the uniform light reflecting element 30, as well as the angle of the uniform light reflecting element 30 in the optical path, are used to achieve the desired effect. Figure 8 As shown, it can also form a relatively dense continuous light spot pattern on the receiving surface, making it suitable for other specific application scenarios.

[0047] In one feasible implementation, the light intensity distribution on the receiving surface after the initial laser beam is uniformly emitted by the uniform light reflecting element 30 satisfies: (peak light intensity - valley light intensity) / peak light intensity ≤ 30%. For example, the light intensity distribution on the receiving surface after the initial laser beam is uniformly emitted by the uniform light reflecting element satisfies: (peak light intensity - valley light intensity) / peak light intensity ≤ 26%.

[0048] The uniform light reflecting element 30 connects the emitted P-beams and S-beams, partially overlaps the light spots, or separates the light spots, such as... Figure 14As shown, the peak and valley values ​​of the light intensity distribution on the receiving surface are homogenized. This means the peak light intensity is weakened, while the valley light intensity is strengthened, reducing the difference between the two. (Peak light intensity - Valley light intensity) / Peak light intensity ≤ 30%. More preferably, (Peak light intensity - Valley light intensity) / Peak light intensity ≤ 26%, indicating better uniformity across the entire light intensity distribution range.

[0049] In one feasible implementation, the divergence angle corresponding to the diameter of the light spot emitted by the point light source 101 on the receiving surface is γ, and the optical axis angle corresponding to the center distance of the light spots emitted by two adjacent point light sources 101 on the receiving surface is α, where α≤2γ.

[0050] Here, we first define the degree of the relationship between the optical axis angle α corresponding to the center distance of the light spots emitted by two adjacent point light sources 101 on the receiving surface and the divergence angle γ corresponding to the diameter of the light spots emitted by the point light sources 101 on the receiving surface.

[0051] Please refer to Figure 8 ,exist Figure 8 As can be seen, if the size of α is larger than the size of γ, then the value of α-γ will be smaller than γ. When the value of α-γ is less than 0.67γ, that is, the value of α-γ is less than two-thirds of the value of γ, then α-γ is considered to be much smaller than γ. (Refer to...) Figure 11 The size of α is equal to, or approximately equal to, the size of γ within a certain range, typically defined as 0.67γ ≤ α - γ ≤ 1.5γ. (Refer to...) Figure 9 As shown, when the size of α is much larger than the size of γ, the value of α-γ is still much larger than γ. When the value of α-γ is greater than 1.5γ, that is, the value of α-γ is still greater than 1.5 times the value of γ, then α-γ is considered to be much larger than γ. The energy distribution of P-beams and S-beams and the homogenization effect after filling are explained below in these cases.

[0052] Please refer to Figure 8 As shown, when α-γ is much smaller than the divergence angle γ corresponding to the diameter of a single light spot, the uniformity of the light spot emitted onto the receiving surface is good. In this case, the discrete gaps between adjacent light spots only require a small amount of energy to fill. Therefore, the P-light used to fill the gaps can be slightly less energetic than the S-light, creating a difference in energy between the P-light and S-light. This means that the smaller gap between the larger-energy polarized light is filled by the smaller-energy polarized light. Figure 8 As shown, the diameter of the light spot on the right is used to represent the energy of the light spot in a graphical way.

[0053] For example, please refer to Figure 9As shown, when α-γ is much larger than the divergence angle γ corresponding to the diameter of a single light spot, the uniformity of the light spot emitted onto the receiving surface is poor. In this case, if only a set of P-beams of equal energy is used to fill the discrete gaps between the S-beams, the result after filling is as follows: Figure 9 As shown, some discrete gaps will still remain unfilled. In such cases, it is necessary to further modulate the polarization state of individual light spots by adding polarization optical elements, such as optical rotators and polarization elements. For example, when the polarization state is as follows: Figure 9 In the case of a large gap shown, a large amount of energy is required to fill the discrete gap between adjacent light spots. Therefore, the energy of the P-light used to fill the gap can be greater than that of the S-light. That is, the polarized light with a larger energy ratio is used to fill the large gap between the polarized light with a smaller energy ratio. Furthermore, the specific difference in light energy can be adjusted according to the difference in the values ​​between α and γ. Alternatively, P-light and S-light with the same energy can be used, and then the number of homogenizing reflective elements 30 in the optical path can be increased to compensate for the gap and finally achieve the homogenization of light spot energy.

[0054] Therefore, as Figure 11 As shown, the optical axis angle corresponding to the center distance of the light spots emitted by two adjacent point light sources 101 on the receiving surface satisfies 0.67γ≤α-γ≤1.5γ. Therefore, even with only one uniform light reflecting element 30, the uniformity of the emitted light spot can be achieved. Furthermore, the light energies of the P-beam and S-beam can be selected as 1:1, allowing a set of P-beams of equal energy to fill the discrete gaps between the S-beams, resulting in a receiving light spot with better light energy homogenization.

[0055] In one feasible implementation, please refer to Figure 5 and Figure 6 As shown, in the Y-axis direction, within the field of view (FOV) of the laser emission module, the angles where uniform light is not applied satisfy the following relationship: α*(2N+1)≤10°; N is a natural number.

[0056] Calculating α*(2N+1) yields the field-of-view range loss caused by the angle between the optical axes of P and S rays along the Y-axis, meaning that some light spots do not fall within the overlapping area, resulting in the inability to achieve uniform light. If α*(2N+1) exceeds 10°, the overlapping area of ​​the light spots is insufficient, leading to significant energy loss from the light source and poor uniform light performance.

[0057] Therefore, the angle of the laser source 10 in the Y-axis direction where homogenization is not performed satisfies the relationship: α*(2N+1)≤10°. This can reduce the impact of a small field of view (FOV) caused by a large unhomogenized portion. More preferably, α*(2N+1)≤2°, thus obtaining a better field of view range for beam energy homogenization. N is a natural number. The larger the value of 2N+1, the smaller the proportion of homogenized light in the FOV. When N=0, all light in the FOV is homogenized. When N=1 or a larger natural number, the light near the edge of the FOV is not homogenized, such as... Figure 10 As shown, the area outside the red box represents the unhomogenized field of view (FOV).

[0058] In one feasible implementation, the arrangement of point light sources 101 in the laser source 10 and the parameters of the uniform light reflecting element 30 satisfy the following relationship: θ=sinβ(N+1 / 2)α,α=d*FOV / L; where β is the angle between the front surface 31 of the uniform light reflecting element 30 and the principal optical axis.

[0059] When the laser emitting module of this application embodiment is used in lidar, such as Figure 10 As shown, in order to make the arrangement of point light sources 101 in laser source 10 match the parameters of uniform light reflection element 30 to achieve the best light output uniformity effect on the receiving surface, so that when the laser emission module is applied to lidar, the ranging performance of lidar is more balanced and the calibration difficulty is reduced, the following relationship should be satisfied: θ=sinβ(N+1 / 2)α.

[0060] For example, when the uniform reflective element 30 is at a 45° angle in the main optical path (e.g.) Figure 1 If β is 45°, then the above relationship simplifies to θ = / 4(2N+1)α. If the relationship is satisfied, the peak and valley values ​​of the P-light and S-light emitted by the uniform light reflecting element 30 can achieve a better overlap ratio. The light intensity in the energy overlap area is relatively uniform, and there will be no local overbrightness or underbrightness. This is more conducive to achieving the best light spot uniformity effect. Refer to the above explanation of the light intensity distribution ratio on the receiving surface, which will not be repeated here.

[0061] In one feasible implementation, the optical lens group 20 includes at least one optical lens. When the optical lens group 20 includes multiple optical lenses, the uniform light reflecting element 30 is located between the multiple optical lenses, or the uniform light reflecting element 30 is located on the light-emitting side of the optical lens group 20.

[0062] For example, such as Figure 12As shown, the optical lens group 20 includes an optical lens, and the uniform light reflecting element 30 is located on the light-emitting side of the optical lens group 20. The uniform light reflecting element 30 is in the main optical path at 45°, that is, β is 45°, and θ satisfies / 4(2N+1)α. Laser source 10 is a VCSEL laser, and point source 101 is the laser beam emitted from a single row of equally spaced emission apertures on the emission side of the VCSEL laser. Point source 101 emits laser beams with the same energy distribution, arranged equally spaced along the first direction. Specifically, the diameter of the emission aperture of the VCSEL laser is 30μm, the aperture spacing is d=47μm, α is 0.15°, L is 6.3mm, the VFOV of the optical lens group 20 is 20° (the VFOV of the lens group is the VFOV of the lidar, i.e., the field of view in the Y-axis direction), and the angle θ between the front surface 31 and the rear surface 32 of the uniform light reflecting element 30 is 0.053°. For example... Figure 13 As shown, Figure 13 The left figure shows the angular spatial energy distribution of the laser beam before passing through the homogenizing reflector 30. Figure 13 The right figure shows the spatial energy distribution of the laser beam angle after homogenization by the homogenizing reflector element 30. For example... Figure 14 As shown, the initial laser beam is incident on the uniform reflector element 30, ( Figure 14 The intensity valley of the light spot (as shown in the image above) is 0. After homogenization by the homogenizing reflective element 30, ( Figure 14 (See the image below) The difference between the peak and valley values ​​of the light spot is reduced to 25% relative to the peak value, achieving the expected uniform light effect.

[0063] It should be noted that, in this embodiment, a VCSEL laser is used as the laser source 10. In fact, the laser source 10 can also use other lasers such as EEL, as long as the laser's light-emitting apertures are spaced apart to form multiple point light sources 101. The arrangement of the multiple point light sources 101 of the laser source 10 can be a single or multiple rows / columns of light-emitting apertures arranged at equal intervals on the laser; it can also be an array of light-emitting apertures formed by units composed of multiple light-emitting apertures of the laser arranged linearly at equal intervals in the Y-axis direction. Moreover, the shape, size, and relative position of the multiple light-emitting apertures within the unit are not specifically limited in this embodiment, and those skilled in the art can make various choices.

[0064] For example, such as Figure 15 As shown, the optical lens group 20 includes two optical lenses, and the uniform light reflecting element 30 is located between the two optical lenses. The uniform light reflecting element 30 is positioned at 45° in the main optical path, i.e., β is 45°, and θ satisfies / 4(2N+1)α, α=d*FOV / L. Laser source 10 is a VCSEL laser, and point source 101 is the laser beam emitted from a single row of equally spaced emission apertures on the emission side of the VCSEL laser. Point source 101 emits laser beams with the same energy distribution, arranged equally spaced along the first direction. Specifically, the diameter of the emission apertures of the VCSEL laser is 24μm, the aperture spacing is d=47μm, α is 0.12°, L is 7.8mm, and the angle θ between the front surface 31 and the rear surface 32 of the uniform light reflecting element 30 is 0.042°. Within a range of 20° emission field of view (FOV) in the Y-axis direction... Figure 16 The image above shows the state of the laser spot received at the receiving surface without beam homogenization by the beam homogenizing reflector 30. Figure 16 The image below shows the state of the laser spot received at the receiving surface after homogenization by the homogenizing reflector 30. Figure 16 The comparison clearly shows that after the homogenization effect of the homogenizing reflector 30, the laser spot received on the receiving surface has a significantly homogenized light intensity.

[0065] Furthermore, when the optical lens group 20 includes more optical lenses, the sequential relationship between the optical lenses and the uniform light reflecting element 30 in the optical path can have many more variations, all of which are within the protection scope of the embodiments of this application.

[0066] In one feasible implementation, the laser source 10 includes a plurality of point light sources 101, which are arranged in an array on a plane perpendicular to the main optical axis.

[0067] For example, still refer to Figure 12 As shown, the multiple point light sources 101 constituting the laser source 10 are arranged in an array on the ZX plane perpendicular to the principal optical axis. The optical lens group 20 includes an optical lens, and the uniform light reflecting element 30 is located on the light-emitting side of the optical lens group 20. The uniform light reflecting element 30 is at 45° in the principal optical path, that is, β is 45°, and θ satisfies / 4(2N+1)α, α=d*FOV / L. The laser source 10 is a VCSEL laser, and the point source array 101 consists of two rows and multiple columns of equally spaced light-emitting apertures on the emitting side of the VCSEL laser. The point source array 101 emits laser beams with the same energy distribution, arranged in an array on a plane perpendicular to the principal optical axis, with each two rows and two columns forming a light-emitting unit. Specifically, the diameter of the light-emitting apertures in the VCSEL laser is 30μm, the aperture spacing is 40μm, the light-emitting unit spacing is d=160μm, α is 0.45°, L is 7.1mm, and the angle between the front surface 31 and the rear surface 32 of the uniform light reflecting element 30 is 0.016°. For example... Figure 14 As shown, the initial laser beam is incident on the uniform reflector element 30, ( Figure 14The intensity valley of the light spot (as shown in the image above) is 0. After homogenization by the homogenizing reflective element 30, ( Figure 14 (See the image below) The difference between the peak and valley values ​​of the light spot is reduced to 26% relative to the peak value, achieving the expected uniform light effect.

[0068] In the example where point light sources 101 in a two-row, two-column array are emitted as units, Figure 17 The image above shows the state of the laser spot received at the receiving surface without beam homogenization by the beam-reflecting element 30. The spot of each of the two-row, two-column point light sources 101 is discrete. Figure 17 The image below shows the state of the laser spot received at the receiving surface after homogenization by the homogenizing reflector 30. Figure 17 The comparison clearly shows that after the homogenization effect of the uniform light reflecting element 30, the gaps between the point light sources 101 arranged in unit form are filled, and the laser spot received on the receiving surface is significantly homogenized in light intensity.

[0069] In one feasible implementation, such as Figure 18 As shown, the uniform light reflecting element 30 includes a first uniform light reflecting element and a second uniform light reflecting element arranged in sequence. The front surface of the first uniform light reflecting element reflects a first polarized light beam, and the front surface of the second uniform light reflecting element reflects a second polarized light beam.

[0070] For example, such as Figure 18 As shown, the optical lens group 20 includes an optical lens. A uniform light reflecting element 30 is located on the light-emitting side of the optical lens group 20. The uniform light reflecting element 30 includes two elements: a first uniform light reflecting element and a second uniform light reflecting element. Both the first and second uniform light reflecting elements are positioned at 45° in the main optical path, i.e., β is 45°, and θ satisfies... / 4(2N+1)α, α=d*FOV / L. The laser source 10 is a VCSEL laser. The angle between the front surface 31 and the rear surface 32 of the first uniform light reflecting element is 0.046°, and the angle between the front surface 31 and the rear surface 32 of the second uniform light reflecting element is 0.046°. The point light source 101 array consists of multiple rows and columns of equally spaced emission holes on the light-emitting side of the VCSEL laser. The point light source 101 array emits laser beams with the same energy distribution, arranged in an array on a plane perpendicular to the principal optical axis. Specifically, the emission hole diameter of the VCSEL laser is 35μm, the emission hole spacing is d=55μm, α is 0.13° in the first direction, α is 0.13° in the second direction, L is 12.7mm in the first direction, L is 8.5mm in the second direction, the field of view of the optical lens group 20 is designed to be 30° in the first direction, and the field of view of the optical lens group 20 in the X direction is designed to be 20°. For example... Figure 19 As shown, by analyzing Figure 19The above diagram illustrates the light intensity effect of the emitted light spot without the homogenization effect of the first and second homogenizing reflective elements. Figure 19 The comparison of the intensity of the emitted light spot after the homogenization effect of the first and second homogenizing reflective elements in the figure below shows that, although Figure 19 The image below is more Figure 19 The image above achieves a certain degree of uniform light distribution, but there is still obvious alternation between light and dark areas, which makes it difficult to meet the uniform light distribution requirements of the emitted light spot in most application scenarios.

[0071] Thus, for example, such as Figure 20 As shown, when the uniform light reflecting element 30 includes a first uniform light reflecting element and a second uniform light reflecting element, the laser emitting module also includes a polarization optical element 50 in the light output direction of the laser source 10, which is used to adjust the polarization parameters of the initial laser beam emitted from the laser source 10. The polarization optical element 50 is located between the first uniform light reflecting element and the second uniform light reflecting element.

[0072] like Figure 20 As shown, in Figure 18 Based on the implementation scheme, a polarization optical element 50 is further provided between the first and second homogenizing reflective elements. For example, in this embodiment, the polarization optical element 50 is a rotator. The polarization state of the laser beam that has passed through the first homogenizing reflective element but has not yet passed through the second homogenizing reflective element is adjusted by the polarization optical element 50, for example, by controlling the ratio of P-beams to S-beams in the laser beam. Figure 21 As shown, by adjusting the polarization parameters of the polarization optical element 50, the initial laser beam can achieve a better homogenization effect after being homogenized by the first homogenizing reflector and the second homogenizing reflector.

[0073] The number of uniform light reflecting elements 30 is not limited to two, but can be more, depending on the adjustment of the polarization parameters of the laser beam by the polarization optical element 50. By cooperating with the polarization optical element 50 to adjust the polarization parameters, a better uniform light effect can be achieved.

[0074] In one feasible implementation, for example, see again. Figure 12 As shown, the optical lens group 20 includes an optical lens, and the uniform light reflecting element 30 is located on the light-emitting side of the optical lens group 20. The included angle of the uniform light reflecting element 30 corresponds to the included angle of the optical axes of the P light and the S light, which is 3α. N is 1. At this time, the light-emitting holes located at both ends that are received on the receiving surface cannot achieve the uniform light effect because the complementary energy of the P light and the S light is not formed.

[0075] The uniform light reflecting element 30 is located at 45° in the main optical path, i.e., β is 45°, and θ satisfies / 4(2N+1)α, α=d*FOV / L. The laser source 10 is a VCSEL laser. The front surface 31 and the rear surface 32 of the uniform light reflecting element 30 have an angle θ in the first direction and the angle is 0.024°. The point light source 101 array emits laser beams with the same energy distribution, which are arranged in an array on a plane perpendicular to the principal optical axis. Specifically, the diameter of the light-emitting aperture of the VCSEL laser is 40μm, the spacing between the light-emitting apertures is d=80μm, L is 6.4mm, the field of view of the optical lens group 20 in the first direction is designed to be 30°, the angle of the reflector corresponds to the optical axis angle of the P-light and the S-light is 3α, that is, N is 1. At this time, the light-emitting apertures at the left and right ends cannot achieve the uniform light effect because the energy of the P-light and the S-light is not complementary. Figure 21 The image below shows two independent energy peaks of uneven light forming at the edge. (See image below.) Figure 22 As shown, by analyzing Figure 22 The above diagram illustrates the light intensity effect of the emitted light spot without the uniform light reflecting element 30. Figure 22 The comparison of the light intensity effect of the uniform light reflecting element 30 in the figure below shows that, before the addition of the uniform light reflecting element 30, such as... Figure 22 As shown in the figure below, the intensity valley of the light spot is 0. After the beam is homogenized by the homogenizing reflector 30, the difference between the peak and valley values ​​of the light spot in the middle region is reduced to 12% relative to the peak value.

[0076] Another aspect of the embodiments of this application provides a lidar, such as... Figure 23 As shown in 24, the laser emitting module including any of the foregoing items also includes a receiving module 60.

[0077] like Figure 23 As shown in diagram 24, a laser beam, collimated and uniformly emitted by the laser emitting module, is emitted towards the target area. After reaching the target, the laser beam is reflected, and the reflected beam is received by the receiving module 60. The laser radar ranging of the target can then be achieved using the received laser beam. Figure 24 Since the reflected beam is in the same direction as the emitted laser beam, it is necessary to add a corresponding reflecting element, such as a reflector, to change the direction of the reflected beam before it is received by the receiving module 60.

[0078] LiDAR systems require optical components to redirect the light path, such as reflecting prisms, which inevitably leads to a relatively large size for the LiDAR unit. For example... Figure 23 As shown, the lidar in this embodiment can achieve the reversal of the optical path in the system through the uniform light reflection element 30 in the laser emission module, thereby reducing the overall layout of the lidar.

[0079] Thus, in the lidar of this embodiment, the uniform light reflecting element 30 in the laser emitting module enables the laser beam to be divided into a first polarized beam 11 and a second polarized beam 12 by the polarization direction through the uniform light reflecting element 30. Furthermore, the first laser beam 41 and the second laser beam 42, ultimately emitted from the front surface 31 of the uniform light reflecting element 30, are emitted at different positions and / or at different angles (in the first direction). Therefore, by adjusting the parameters of the laser source 10 and the uniform light reflecting element 30, the first laser beam 41 and the second laser beam 42 can achieve a connection between their light spots on the receiving surface after emission, thereby achieving light spot uniformity. The lidar using this laser emitting module exhibits better uniformity in laser beam intensity, resulting in more balanced ranging performance, reduced calibration difficulty, and the elimination of necessary optical path deflection elements by sharing the uniform light reflecting element 30, thereby saving on module size.

[0080] In some feasible implementations, such as Figure 25 As shown in Figure 26, the lidar also includes a scanning module 70. The laser beam emitted from the laser emitting module is scanned and emitted by the scanning module 70, and the reflected beam is received by the receiving module 60.

[0081] For example, such as Figure 25 As shown, a lidar can be configured with a laser emitting module and a receiving module 60 facing each other. A scanning module 70 rotates around an axis to scan and emit a laser beam homogenized by the laser emitting module. The emitted laser beam reflects back after reaching an obstacle, and the reflected beam is received by the receiving module 60 after passing through the scanning module 70, thus enabling the lidar to measure distances.

[0082] In some implementations of lidar, such as Figure 26 As shown, a lidar can also be configured such that the laser emitting module and the receiving module 60 are located on the same side. In this configuration, the laser beam emitted by the laser emitting module and the laser beam received by the receiving module 60 are both achieved through the same side of the scanning module 70. This type of lidar requires the addition of a reflector to the receiving module 60 in the optical system.

[0083] In another aspect of this application, an electronic device is provided, which, in addition to fulfilling its own functions, also includes a lidar as described above. By configuring the lidar, detection functions such as ranging and obstacle avoidance can be achieved.

[0084] In this application, the electronic devices can be electronically controlled driving devices such as vehicles, ships, and aircraft; single-function electronic devices such as rangefinders; customized electronic devices with multiple functions such as robots; or other forms or types of electronic devices. This application does not specifically limit the type of electronic device. By incorporating the lidar of this application into various electronic devices, including the examples above, the detection function of the lidar can be achieved with balanced performance and stable operation while ensuring the functionality of the electronic device itself. Because the lidar has a reasonable overall layout and compact structure, it does not significantly increase the size of the electronic device.

[0085] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A laser emission module, characterized by, The system includes a laser source and a uniform light reflecting element disposed in the light emission direction of the laser source. The laser source includes multiple point light sources, which are spaced apart along a first direction. In the plane formed by the light emission direction of the laser source and the first direction, there is an angle θ between the front and rear surfaces of the uniform light reflecting element. There is an angle β between the principal optical axis of the initial laser beam and the front surface of the uniform light reflecting element. The angle β and the angle θ are respectively in two non-parallel planes. The initial laser beam is reflected by the uniform light reflecting element and emitted as a first laser beam and a second laser beam. The second laser beam is emitted at a offset relative to the first laser beam in the first direction.

2. The laser emission module of claim 1, wherein, The initial laser beam emitted from the laser source includes a first polarized beam and a second polarized beam. The polarization direction of the first polarized beam is perpendicular to the polarization direction of the second polarized beam. The first polarized beam is reflected by the front surface of the uniform light reflecting element and emitted as the first laser beam. The second polarized beam passes through the front surface, enters the uniform light reflecting element, and is reflected by the rear surface and emitted as the second laser beam.

3. The laser emission module of claim 2, wherein, The uniform light reflecting element includes a transparent optical medium and a polarizing film layer and a reflective film layer respectively deposited on two opposite surfaces of the transparent optical medium, wherein the polarizing film layer is adapted to reflect the first polarized light beam and transmit the second polarized light beam.

4. The laser emission module according to any one of claims 1 to 3, characterized in that The angle between the first laser beam and the second laser beam emitted from the same point light source through the uniform light reflecting element is (N+1 / 2)α, where α is the optical axis angle corresponding to the center distance between the emitted light spots of two adjacent point light sources.

5. The laser emission module according to any one of claims 1 to 3, wherein The light intensity distribution on the receiving surface after the initial laser beam is uniformly emitted by the uniform light reflecting element satisfies: (Peak light intensity - Valley light intensity) / Peak light intensity ≤ 30%.

6. The laser emission module of claim 5, wherein, The light intensity distribution on the receiving surface after the initial laser beam is uniformly emitted by the uniform light reflecting element satisfies: (Peak light intensity - Valley light intensity) / Peak light intensity ≤ 26%.

7. The laser emitting module of claim 4, wherein, The included angle θ between the front and rear surfaces of the uniform light reflecting element is ≤5°.

8. The laser emission module of claim 7, wherein, The included angle θ between the front and rear surfaces of the uniform light reflecting element satisfies: 0 < θ ≤ 1.5°.

9. The laser emitting module according to claim 4, characterized in that, The distance between the front and rear surfaces of the uniform light reflecting element is less than or equal to 20 mm.

10. The laser emitting module of claim 9, wherein, The distance between the front and rear surfaces of the uniform light reflective element is between 0.5 mm and 5 mm.

11. The laser emission module according to claim 2 or 3, characterized in that, The divergence angle of the emitted light spot from the point light source is γ, and the optical axis angle corresponding to the center distance between two adjacent emitted light spots from the point light source is α, where α≤2γ.

12. The laser emitting module of claim 11, wherein, When 0.67γ≤α-γ≤1.5γ, the ratio of the first polarized beam and the second polarized beam included in the initial laser beam is approximately 1:

1.

13. The laser emitting module of claim 11, wherein, When α-γ < 0.67γ, in the ratio of the first polarized beam and the second polarized beam included in the initial laser beam, the light energy of the first polarized beam is greater than that of the second polarized beam, or the light energy of the first polarized beam is less than that of the second polarized beam.

14. The laser emitting module according to claim 2 or 3, characterized in that, The field of view angles of the first polarized light and the second polarized light in the first direction of the non-uniform light satisfy the following relationship: α*(2N+1)≤10°; N is a natural number.

15. The laser emitting module of claim 14, wherein, The field of view of the laser source in the first direction satisfies the following relationship: α*(2N+1)≤2°; N is a natural number.

16. The laser launch module of any one of claims 1-3, wherein, The setting of the point light source in the laser source and the setting parameters of the uniform light reflection element satisfy the following relationship: θ = sinβ(N+1 / 2)α; where β is the angle between the front surface of the uniform light reflecting element and the principal optical axis.

17. The laser launch module of any one of claims 1-3, wherein, An optical lens group is also provided in the light emission direction of the laser source. The optical lens group includes at least one optical lens. When the optical lens group includes multiple optical lenses, the uniform light reflecting element is disposed between the multiple optical lenses. Alternatively, the uniform light reflecting element is disposed on the light emission side of the optical lens group.

18. The laser emitting module according to claim 2 or 3, characterized in that, The initial laser beam is optically modulated into a first polarized beam and a second polarized beam. The optical modulation includes polarization modulation of the laser source to produce the first polarized beam and the second polarized beam, or a polarization optical element is provided in the output direction of the laser source to adjust the polarization parameters of the initial laser beam emitted by the laser source to produce the first polarized beam and the second polarized beam.

19. The laser emitting module according to claim 2 or 3, characterized in that, Multiple point light sources are arranged in an array on a plane perpendicular to the principal optical axis.

20. The laser launch module of claim 19, wherein, The light-uniform reflecting element includes a first light-uniform reflecting element and a second light-uniform reflecting element arranged sequentially. The front surface of the first light-uniform reflecting element reflects a first polarized light beam, and the front surface of the second light-uniform reflecting element reflects a second polarized light beam.

21. A lidar, comprising: The system includes the laser emitting module as described in any one of claims 1-20, and further includes a receiving module.

22. The lidar of claim 21, wherein, It also includes a scanning module, in which the laser beam emitted by the laser emitting module is scanned out by the scanning module, and the reflected beam is received by the receiving module.

23. An electronic device, comprising: Including the lidar as described in claim 21 or 22.

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