Laser radar transmitting end

Abstract

The application provides a laser radar emitting end and a method for manufacturing the laser radar emitting end, wherein the laser radar emitting end comprises: a light source module comprising at least one laser light source; and a diffraction module arranged on an optical path of light emitted by the light source module and used for performing optical diffraction processing on the light emitted by the light source module. The diffraction module comprises a plurality of single gratings, so as to deflect the light emitted by the light source module, so that the diffracted light achieves an expected diffraction angle. The emitted light of the laser radar emitting end of the application can achieve a longer detection distance.

Description

Technical Field

[0001] This application relates to the field of optical equipment technology, and more specifically, to a lidar transmitter. Background Technology

[0002] LiDAR plays a crucial role in autonomous driving. Traditional LiDAR transmitters can be categorized as follows: transmitters based on orthogonal cylindrical mirrors, transmitters based on diffuser plates with flood illumination, and transmitters based on traditional diffraction elements (non-grating). Both orthogonal cylindrical mirror-based and diffuser plate-based transmitters use flood illumination. However, since the actual photosensitive area in the LiDAR receiver chip only occupies about 18% of the chip area, most of the emitted light cannot be received by the photosensitive area when using flood illumination at the transmitter. In contrast, transmitters based on diffraction elements emit a dot matrix of light, allowing for full photosensitive reception through special design. Therefore, under the same conditions, the detection range of LiDAR transmitters using orthogonal cylindrical mirrors and diffuser plates with flood illumination is shorter than that of LiDAR transmitters using traditional diffraction elements.

[0003] However, while traditional lidar transmitters based on diffraction elements can achieve long detection ranges, these transmitters have strict requirements for the incident light, which must be parallel. Therefore, a collimating lens must be added between the diffraction element and the light source in the transmitter. The addition of the collimating lens increases the cost of manufacturing the lidar transmitter.

[0004] To solve the above problems, there is an urgent need for a new type of lidar transmitter that does not require a collimating lens and uses a diffraction element. That is, after the light from the light source directly illuminates the surface of the diffraction element, the required diffusion angle of the lidar transmitter can be achieved without adding other components or performing other processes, thus meeting the detection requirements. Summary of the Invention

[0005] This application provides a lidar transmitter that can at least solve or partially solve at least one of the above-mentioned drawbacks in the prior art.

[0006] This application provides a lidar transmitter, comprising: a light source module including at least one laser light source; and a diffraction module disposed on the optical path of the light emitted by the light source module for optical diffraction processing of the light, wherein the diffraction module includes multiple individual gratings to deflect the light so that the diffracted light achieves a desired diffraction angle.

[0007] According to an embodiment of this application, the number of individual gratings is the same as the number of detection points generated by the lidar transmitter.

[0008] According to the embodiments of this application, the diffraction angles α1 and β1 of the diffracted light corresponding to the single grating are the negative first-order diffraction angles of the diffracted light, wherein α1 is the angle between the diffracted light and the first axis x in the Cartesian vertical coordinate system; and β1 is the angle between the diffracted light and the third axis z in the Cartesian vertical coordinate system.

[0009] According to an embodiment of this application, the single grating includes a grating substrate and a plurality of microstructures formed on one surface of the grating substrate.

[0010] According to embodiments of this application, the grating substrate and the plurality of microstructures form at least one of a one-dimensional grating, a two-dimensional grating, and a tilted grating.

[0011] According to an embodiment of this application, the microstructure is formed from at least one coating material selected from PMMA, UV adhesive, and photoresist.

[0012] According to embodiments of this application, multiple microstructures of the same single grating have the same distribution period and orientation angle.

[0013] According to an embodiment of this application, the distribution period Λ of the plurality of microstructures in the single grating satisfies: Wherein, α is the angle between the light emitted by the light source module and the first axis x in the Cartesian vertical coordinate system; β is the angle between the light emitted by the light source module and the third axis z in the Cartesian vertical coordinate system; α1 is the angle between the diffracted light emitted by the single grating and the first axis x in the Cartesian vertical coordinate system; β1 is the angle between the diffracted light emitted by the single grating and the third axis z in the Cartesian vertical coordinate system; λ is the wavelength of the light emitted by the light source module; and n is the refractive index of the single grating in the diffraction module.

[0014] According to an embodiment of this application, the orientation angle φ of the plurality of microstructures in the single grating satisfies: Wherein, φ is the angle between the normals of the plurality of microstructures in the single grating and the second axis y in the Cartesian vertical coordinate system; α is the angle between the light emitted by the light source module and the first axis x in the Cartesian vertical coordinate system; β is the angle between the light emitted by the light source module and the third axis z in the Cartesian vertical coordinate system; α1 is the angle between the diffracted light emitted by the single grating and the first axis x in the Cartesian vertical coordinate system; and β1 is the angle between the diffracted light emitted by the single grating and the third axis z in the Cartesian vertical coordinate system.

[0015] According to embodiments of this application, multiple microstructures of the same single grating have the same shape.

[0016] According to embodiments of this application, multiple microstructures of the same single grating have different shapes.

[0017] According to an embodiment of this application, the microstructures protrude from the grating substrate at the same height.

[0018] According to embodiments of this application, the height at which the microstructure protrudes from the grating substrate is different.

[0019] According to embodiments of this application, the grating substrate is formed of at least one material selected from glass, PC, and PV. This application provides a method for fabricating the aforementioned lidar transmitter, wherein the method includes: coating a grating substrate with an adhesive to form an adhesive film layer on its surface; exposing the substrate with the adhesive film layer in an interference field; immersing the exposed grating substrate in a developing solution to form the diffraction module comprising a plurality of individual gratings having structures protruding from the grating substrate; and positioning the diffraction module in the optical path of the emitted light from the light source module.

[0020] According to an embodiment of this application, the diffraction module substrate includes at least one of glass, PC, and PV.

[0021] According to an embodiment of this application, coating the grating substrate includes applying a coating using one of PMMA, UV adhesive, and photoresist on the grating substrate. According to an embodiment of this application, the diffraction angles α1 and β1 of the diffracted light corresponding to the single grating are the negative first-order diffraction angles of the diffracted light, where α1 is the angle between the diffracted light and the first axis x in the Cartesian vertical coordinate system; and β1 is the angle between the diffracted light and the third axis z in the Cartesian vertical coordinate system.

[0022] According to an embodiment of this application, placing the exposed grating substrate in a developing solution to form the diffraction module comprising a plurality of individual gratings protruding from the grating substrate includes: placing the exposed grating substrate in a developing solution to form a plurality of individual gratings comprising microstructures protruding from the grating substrate, wherein the number of individual gratings is the same as the number of detection points generated by the lidar transmitter.

[0023] According to an embodiment of this application, the step of placing the exposed grating substrate in a developing solution to form a plurality of individual gratings includes: placing the exposed grating substrate in a developing solution to form a plurality of individual gratings with surface microstructures, wherein the individual gratings with surface microstructures are at least one of a one-dimensional grating, a two-dimensional grating, and a tilted grating.

[0024] According to the embodiments of this application, the distribution period and orientation angle of multiple microstructures of the same single grating are the same.

[0025] According to an embodiment of this application, the distribution period Λ of the plurality of microstructures in the single grating satisfies: Wherein, α is the angle between the light emitted by the light source module and the first axis x in the Cartesian vertical coordinate system; β is the angle between the light emitted by the light source module and the third axis z in the Cartesian vertical coordinate system; α1 is the angle between the diffracted light emitted by the single grating and the first axis x in the Cartesian vertical coordinate system; β1 is the angle between the diffracted light emitted by the single grating and the third axis z in the Cartesian vertical coordinate system; λ is the wavelength of the light emitted by the light source module; and n is the refractive index of the single grating in the diffraction module.

[0026] According to an embodiment of this application, the orientation angle φ of the plurality of microstructures in the single grating satisfies: Wherein, φ is the angle between the normals of the plurality of microstructures in the single grating and the second axis y in the Cartesian vertical coordinate system; α is the angle between the light emitted by the light source module and the first axis x in the Cartesian vertical coordinate system; β is the angle between the light emitted by the light source module and the third axis z in the Cartesian vertical coordinate system; α1 is the angle between the diffracted light emitted by the single grating and the first axis x in the Cartesian vertical coordinate system; and β1 is the angle between the diffracted light emitted by the single grating and the third axis z in the Cartesian vertical coordinate system.

[0027] According to the embodiments of this application, multiple microstructures of the same single grating have the same structure.

[0028] According to embodiments of this application, multiple microstructures of the same single grating have different structures.

[0029] According to an embodiment of this application, the microstructures protrude from the grating substrate at the same height.

[0030] According to embodiments of this application, the height at which the microstructure protrudes from the grating substrate is different.

[0031] At least one solution for the lidar transmitter provided in this application can achieve at least one of the following beneficial effects:

[0032] 1. The lidar transmitter of this application uses multiple single gratings with surface microstructures to form a diffraction module, replacing the collimating lens and its corresponding diffraction module used in the prior art, thereby achieving the diffusion angle required by the lidar, making the lidar smaller and less expensive to produce.

[0033] 2. Under the same operating conditions, compared with the detection light emitted by the lidar transmitter using floodlight illumination in the prior art, the diffraction light emitted by the lidar transmitter of this application can achieve a longer detection distance. Attached Figure Description

[0034] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0035] Figure 1 This is a schematic diagram of the structure of the diffraction module of a lidar transmitter according to one embodiment of this application;

[0036] Figure 2 This is a schematic diagram of a lidar transmitter according to one embodiment of this application;

[0037] Figure 3 This is a schematic diagram illustrating the principle of optical diffraction generated by a single grating in the diffraction module of this application;

[0038] Figure 4 This is a schematic diagram of a one-dimensional grating according to one embodiment of this application;

[0039] Figure 5 This is a schematic diagram of the structure of a two-dimensional grating according to one embodiment of this application;

[0040] Figure 6 This is a schematic diagram of the structure of a slanted grating according to one embodiment of this application;

[0041] Figure 7 This is a flow chart of a single-unit grating according to one embodiment of this application;

[0042] Figure 8 This is a diffused light field pattern of a lidar transmitter according to one embodiment of this application; and

[0043] Figure 9 It is the diffraction efficiency value of a single grating with a microstructure having a different distribution period according to one embodiment of this application, which varies with the height of the microstructure. Detailed Implementation

[0044] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0045] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of this application, the first axis discussed below may also be referred to as the second axis, and vice versa.

[0046] In the accompanying drawings, the thickness, dimensions, and shapes of the parts have been slightly adjusted for ease of illustration. The drawings are for illustrative purposes only and are not drawn to scale. As used herein, the terms “approximately,” “about,” and similar terms are used as expressions of approximation, not as expressions of degree, and are intended to illustrate inherent deviations in measured or calculated values ​​that will be recognized by one of ordinary skill in the art.

[0047] It should also be understood that expressions such as "comprising," "including," "having," "containing," and / or "comprising" are open-ended rather than closed-ended expressions in this specification, indicating the presence of the stated features, elements, and / or components, but not excluding the presence of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not just individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to examples or illustrations.

[0048] Unless otherwise specified, all terms used herein (including engineering and technical terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that, unless expressly stated herein, terms defined in common dictionaries shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art, and not as having an idealized or overly formalized meaning.

[0049] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. Furthermore, unless explicitly limited or contradicted by the context, the specific steps included in the methods described in this application are not limited to the order in which they are described, but can be performed in any order or in parallel. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0050] Figure 1 This is a schematic diagram of the structure of the diffraction module 1200 of the lidar transmitter 1000 according to one embodiment of this application; and Figure 2 This is a schematic diagram of a lidar transmitter 1000 according to one embodiment of this application.

[0051] like Figure 2As shown, a lidar transmitter 1000 according to one embodiment of this application may include a light source module 1100 and a diffraction module 1200.

[0052] The light source module 1100 includes at least one laser light source. It should be understood that the main process of distance measurement in a lidar system is as follows: the lidar system emits a laser beam to the surrounding area; when the beam reaches the surface of the object being measured, the object reflects the beam; the lidar system identifies the beam reflected back from the object and calculates the distance to the object based on relevant information about the reflected beam (e.g., imaging position, time of flight, phase information, etc.).

[0053] According to one embodiment of this application, the wavelength of the laser to be output can be selected and adjusted as needed in the light source module 1100. The light source module 1100 can be fixedly mounted on a mounting bracket, such as on a lidar housing. Furthermore, the light source module 1100 may also be equipped with auxiliary devices (not shown), such as a reflector for changing the projection direction of the light emitted by the light source module 1100 or an adjustable bracket for fixing the light source module 1100. Those skilled in the art will understand that, without departing from the technical solutions claimed in this application, the composition, structure, and installation position of the light source module at the lidar transmitter can be changed to obtain the various results and advantages described in this specification.

[0054] refer to Figure 2 The system of the lidar transmitter 1000 also includes a diffraction module 1200, which is disposed in the optical path of the light emitted by the light source module 1100. The diffraction module 1200 is used to perform optical diffraction processing on the light emitted by the light source module 1100. Figure 1 As shown, the diffraction module 1200 includes multiple individual gratings 1220, which are arranged in an array on a grating substrate 1210. The number of individual gratings 1220 is the same as the number of detection points generated by the lidar transmitter 1000. The surface of each individual grating 1220 has multiple microstructures 1221. The multiple microstructures 1221 can be formed by coating the grating substrate 1210 with a photoresist, followed by exposure and development, which will be described separately later.

[0055] Figure 3 This is a schematic diagram illustrating the principle of optical diffraction generated by a single grating in the diffraction module of this application. (See attached diagram.) Figure 3As shown, a Cartesian coordinate system is established in space. In this coordinate system, the individual grating 1220 is positioned on the light path emitted by the light source module 1100, and lies in the xz plane containing the mutually perpendicular first axis x and the third axis z. The normal directions of the multiple microstructures 1221 included in the individual grating 1220 maintain an angle φ with the second axis y. Because the multiple microstructures 1221 in an individual grating 1220 are parallel to each other and their normal directions are the same, the angle φ can represent the orientation of the multiple microstructures 1221 in the individual grating; that is, the angle φ is also the orientation angle of the multiple microstructures 1221 in the individual grating 1220. The orientation angles of the multiple microstructures 1221 in the same individual grating are the same. Light emitted from the light source module 1100 is directed towards the individual grating 1220. The angle between the incident light and the first axis x is α, and the angle between the incident light and the third axis z is β. After diffraction by the individual grating 1220, the optical path of the diffracted light is deflected, and the angle between the diffracted light and the first axis x becomes α1, and the angle between the diffracted light and the third axis z becomes β1. The diffraction angles α1 and β1 of the diffracted light corresponding to the individual grating 1220 are the negative first-order diffraction angles of the diffracted light. In the embodiments of this application, the diffraction module is composed of multiple individual gratings 1220 arranged in an array on the grating substrate 1210. After the light emitted from the light source module 1100 undergoes optical diffraction by the multiple individual gratings 1220, the multiple diffracted lights undergo predetermined optical path deflection, achieving the expected diffraction angle, and together achieving the required diffusion angle of the lidar transmitter 1000. The aforementioned predetermined optical path deflection can be achieved by designing the shape, height (i.e., the height of the microstructure protruding from the grating substrate), distribution period, and orientation angle of the multiple microstructures 1221 included in the single grating 1220. In the same single grating, multiple microstructures have the same distribution period and orientation angle.

[0056] According to the generalized grating diffraction equation, given that the incident light angles α and β and the spatial angles α1 and β1 of the negative first-order diffracted light are determined, the distribution period and orientation angle of multiple microstructures in a single grating can be determined by the following formula:

[0057] Among them, the distribution period Λ of multiple microstructures in a single grating satisfies:

[0058]

[0059] The orientation angle φ of multiple microstructures in a single grating satisfies:

[0060]

[0061] Figure 4 This is a schematic diagram of a one-dimensional grating 1220 having a microstructure 1221 according to an embodiment of this application; Figure 5This is a schematic diagram of the structure of a two-dimensional grating 1220 having a microstructure 1221 according to one embodiment of this application; and Figure 6 This is a schematic diagram of the structure of a slanted grating 1220 having a microstructure 1221 according to one embodiment of this application.

[0062] The single-unit grating 1220 included in the diffraction module 1200 can be, for example... Figures 4 to 6 The diagram shows one of a one-dimensional grating, a two-dimensional grating, and a tilted grating with a microstructure 1221. Furthermore, the diffraction module 1200 may choose a one-dimensional grating with a microstructure 1221 to meet the dual requirements of reducing the production cost of the lidar transmitter 1000 and improving its overall optical efficiency.

[0063] In one embodiment of this application, a single grating 1220 has multiple microstructures 1221. The multiple microstructures 1221 can be selected in different shapes, such as strips, inclined shapes, cylindrical shapes, prismatic shapes, etc. Without departing from the technical solution claimed in this application, the shape of the microstructures on the grating surface can be changed to obtain the various results and advantages described in this specification, so as to achieve the target light effect of the lidar transmitter.

[0064] Furthermore, the multiple microstructures 1221 of the same single grating 1220 may have the same shape or different shapes.

[0065] Furthermore, the microstructures 1221 of the same single grating 1220 may have the same height or different heights, and the microstructures 1221 of different single gratings 1220 may also have the same height or different heights. The aforementioned height is the height by which the microstructure 1221 protrudes from the grating substrate 1210.

[0066] like Figure 4 As shown, the microstructure 1221 of the single-unit grating 1220 is an elongated protrusion with a certain height h. The height h of the microstructure 1221 refers to the height extending from the surface of the grating substrate 1210 where the microstructure 1221 is located and along the normal direction of that surface; that is, the height protruding from the grating substrate 1210. In the single-unit grating 1220 shown, multiple microstructures 1221 have the same height, shape, and size. That is, a single-unit grating 1220 has multiple identical microstructures 1221 or identical microstructure units 1221 (a microstructure unit refers to a unit comprising multiple different microstructures, and this unit can be repeatedly arranged on the surface of the grating), which are regularly arranged on the surface of the single-unit grating 1220. The sum of the spacing between two adjacent elongated protrusions and the size of a single elongated protrusion is the distribution period Λ of the microstructures in the single-unit grating. Figure 5As shown, the sum of the spacing between two identical cylindrical protrusions and the size of a single cylindrical protrusion constitutes the distribution period of the microstructure; as... Figure 6 As shown, the sum of the spacing between two identical inclined protrusions and the size of a single inclined protrusion is the distribution period of the microstructure. The distribution period of the microstructure can be set using the formula (1) above.

[0067] In one embodiment of this application, the multiple microstructures of the same single grating should have the same distribution period of the aforementioned microstructures.

[0068] exist Figure 4 In the process of designing and manufacturing a single-unit grating, the width of the elongated protrusion is the grating width d of the single-unit grating 1220. The ratio of the grating width d to the distribution period Λ is the duty cycle of the single-unit grating. In the process of designing and manufacturing a single-unit grating, the structure of the single-unit grating can be effectively adjusted by changing the duty cycle of the single-unit grating, thereby changing the diffraction angle of the light diffracted by the single-unit grating.

[0069] Meanwhile, in one embodiment of this application, the orientation angle of the microstructure can be designed according to the above formula (2) according to different needs, and multiple microstructures of the same single grating have the same orientation angle.

[0070] Furthermore, in one embodiment of this application, the fabrication method of the lidar transmitter 1000 will be described in detail. First, a diffraction module 1200 required for the lidar transmitter 1000 should be fabricated. The diffraction module 1200 is composed of multiple individual gratings 1220. Figure 7 This is a flow chart of the fabrication of a single-unit grating 1220 according to one embodiment of this application. Figure 7 As shown, the process for fabricating the single-unit grating 1220 is as follows:

[0071] The grating substrate is cleaned with a cleaning solution, rinsed, and dried. The grating substrate can be at least one of glass, PC, and PV.

[0072] One of the following can be used, such as PMMA, UV adhesive and photoresist, to coat the grating substrate to form an adhesive film layer on its surface;

[0073] The substrate into which the adhesive film layer is formed is exposed in an interference field;

[0074] A diffraction module is formed by immersing an exposed grating substrate in a developing solution to create multiple individual gratings, each with a structure protruding from the grating substrate. This can be achieved by immersing the exposed grating substrate in the developing solution to form multiple individual gratings, each with a microstructure protruding from the grating substrate. The number of individual gratings is the same as the number of detection points generated by the lidar transmitter.

[0075] After the diffraction module is prepared, it is placed on the optical path of the emitted light from the fixed light source module.

[0076] Furthermore, this application takes a lidar transmitter capable of emitting a 32×32 dot matrix diffused light field as an example to describe in detail the structure of the diffraction module. The lidar transmitter needs to achieve a diffusion angle of 20°×20°. The light source module of this lidar transmitter includes at least one laser source, and the emitted light has a diffusion angle of 12.5°×25° and a wavelength of 905nm.

[0077] The diffraction module of this lidar can use glass, PC, PV, etc. as the grating substrate, and use PMMA, UV adhesive and photoresist to coat the grating substrate to form an adhesive film layer on its surface. Then, the diffraction module is prepared by the above-mentioned lidar transmitter preparation method. According to formulas (1) and (2) of this application, the diffraction module includes 32×32 individual gratings. The distribution period Λ of the microstructure in each individual grating is selected between 800nm ​​and 2000nm, the orientation angle φ of the microstructure is selected between -40° and 40°, the height h of the microstructure can be 800nm, and the duty cycle can be 0.5. When the light emitted by the light source module reaches the surface of the diffraction module, each individual grating produces negative first-order diffraction. After optical path deflection, the 32×32 individual gratings produce 32×32 negative first-order diffracted lights, such as Figure 8 As shown, the diffraction angles of each diffracted beam collectively form a 20° × 20° diffusion range, achieving the diffusion angle required by the lidar transmitter. Furthermore, the diffraction efficiency η of all diffracted beams is between 36% and 40%.

[0078] Furthermore, the higher the diffraction efficiency η of the diffracted light emitted by the lidar transmitter, the higher its light energy utilization rate and the farther the detection distance under the same conditions. Therefore, in one embodiment of this application, the light energy utilization rate of the lidar transmitter can be improved by making all or part of the height of each individual grating different, or by tilting the microstructure in each individual grating to improve the diffraction efficiency η of the diffraction module, thereby improving the light energy utilization rate of the lidar transmitter.

[0079] Figure 9 This refers to the diffraction efficiency value η of a single grating 1220 with microstructures 1221 having different distribution periods Λ, according to one embodiment of this application, as the height h of the microstructures 1221 varies. Furthermore, the height h of each single grating 1220 in the above embodiment can be completely or partially different according to different needs, or different shapes can be selected for the microstructures 1221 in each single grating 1220, such as elongated, inclined, cylindrical, prismatic, etc., to improve the diffraction efficiency of the diffracted light emitted from the lidar transmitter, thereby improving the light energy utilization rate.

[0080] The above description is merely an illustration of the embodiments of this application and the technical principles employed. Those skilled in the art should understand that the scope of protection involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the technical concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A laser radar transmitting end, comprising: a light source module comprising at least one laser light source; and a diffraction module arranged in an optical path of light emitted by the light source module and configured to perform optical diffraction on the light, characterized in that the diffraction module comprises a plurality of unit gratings configured to deflect the light so that the diffracted light achieves a desired diffraction angle, wherein a number of the unit gratings is the same as a number of probe points generated by the laser radar transmitting end; and a plurality of microstructures of a same unit grating have a same distribution period and orientation angle; wherein a duty cycle of the unit grating is configured to adjust the diffraction angle of the diffracted light emitted by the unit grating, and the duty cycle of the unit grating is a ratio of a grating width of the unit grating to the distribution period, wherein the orientation angle φ of the plurality of microstructures in the unit grating satisfies: wherein φ is an included angle between a normal line of the plurality of microstructures in the unit grating and a second axis y in a Cartesian perpendicular coordinate system; α is an included angle between the light emitted by the light source module and a first axis x in the Cartesian perpendicular coordinate system; β is an included angle between the light emitted by the light source module and a third axis z in the Cartesian perpendicular coordinate system; α1 is an included angle between the diffracted light emitted by the unit grating and the first axis x in the Cartesian perpendicular coordinate system; and β1 is an included angle between the diffracted light emitted by the unit grating and the third axis z in the Cartesian perpendicular coordinate system. The α1 and the β1 are negative first-order diffraction angles of the diffracted light.

2. The transmitting terminal of claim 1, wherein The unit grating comprises a grating substrate and the plurality of microstructures formed on a surface of the grating substrate.

3. The transmitting terminal of claim 1, wherein The grating substrate and the plurality of microstructures form at least one of a one-dimensional grating, a two-dimensional grating, and an inclined grating.

4. The transmitting terminal of claim 3, wherein The distribution period Λ of the plurality of microstructures in the unit grating satisfies:

5. The transmitting terminal of claim 3, wherein, wherein α is an included angle between the light emitted by the light source module and a first axis x in a Cartesian perpendicular coordinate system; β is an included angle between the light emitted by the light source module and a third axis z in the Cartesian perpendicular coordinate system; α1 is an included angle between the diffracted light emitted by the unit grating and the first axis x in the Cartesian perpendicular coordinate system; β1 is an included angle between the diffracted light emitted by the unit grating and the third axis z in the Cartesian perpendicular coordinate system; λ is a wavelength of the light emitted by the light source module; and n is a refractive index of the unit grating in the diffraction module. The plurality of microstructures of a same unit grating have a same shape.

6. The transmitting terminal according to any one of claims 3-5, c h a r a c t e r i z e d b y The plurality of microstructures of a same unit grating have different shapes.

7. The transmitting terminal according to any one of claims 3-5, c h a r a c t e r i z e d b y The microstructures have a same height protruding from the grating substrate.

8. The transmitting terminal according to any one of claims 3-5, c h a r a c t e r i z e d b y The microstructures have different heights protruding from the grating substrate.

9. The transmitting terminal according to any one of claims 3-5, c h a r a c t e r i z e d b y The method comprises:

10. A method for producing a ladar launch as claimed in any one of claims 1-9, characterized by applying glue on the grating substrate to form a glue film layer on a surface thereof; exposing the grating substrate on which the glue film layer is formed to an interference field; forming the diffraction module comprising a plurality of unit gratings having a structure protruding from the grating substrate by placing the exposed grating substrate in a developing solution; and arranging the diffraction module in an optical path of light emitted by the light source module. ​ The number of the single gratings is the same as the number of the detection points generated by the laser radar emitting end. The duty cycle of the single grating is used to adjust the diffraction angle of the diffracted light emitted through the single grating, and the duty cycle of the single grating is the ratio of the grating width of the single grating to the distribution period. The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies:

11. The method of claim 10, wherein, said a1 and said β1 is the negative first order diffraction angle of said diffracted light rays.

12. The method of claim 10, wherein, The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies:

13. The method of claim 12, wherein, The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies:

14. The method of claim 12, wherein, The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies:

15. The method of claim 12, wherein, The orientation angle φ of the plurality of microstructures in the single grating satisfies:

16. The method of claim 12, wherein, The orientation angle φ of the plurality of microstructures in the single grating satisfies:

17. The method of claim 12, wherein, The orientation angle φ of the plurality of microstructures in the single grating satisfies:

18. The method of claim 12, wherein, The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the single grating satisfies: The orientation angle φ of the plurality of microstructures in the

Images