Design method of emission optical assembly, light emission module and laser radar

Abstract

The invention provides a design method of a transmitting optical assembly for a laser radar, a light transmitting module for the laser radar and the laser radar, the transmitting optical assembly comprises a metasurface lens, and the design method comprises the following steps: acquiring parameters of a transmitting device of the laser radar; acquiring parameters of a target view field of the laser radar; and designing a metasurface lens according to the parameters of the transmitting device and the parameters of the target view field, so that the target view field can be obtained after the detection light beam transmitted by the transmitting device passes through the metasurface lens. According to the embodiment of the invention, the metasurface lens is designed according to the parameters of the transmitting device of the laser radar and the parameters of the target field of view, the metasurface lens can be used to form the required target field of view, the selectable range of the emergent field of view of the laser radar is greatly enriched, the field of view requirements of the laser radar in different scenes are met, and the use experience of the laser radar is improved. The processing requirement for the transmitting device is reduced, and the use of a separately packaged laser can be avoided, thereby facilitating the miniaturization of the laser radar.

Description

Technical Field

[0001] The present invention generally relates to the field of laser radar technology, and in particular to a design method for a transmitting optical component for a laser radar, a light transmitting module for a laser radar, and a laser radar. Background Art

[0002] In conventional laser radar designs, the transmitting end uses an array of multiple discrete lasers or an array laser cut directly from a wafer (such as a vertical cavity surface emitting laser [VCSEL]). The detection beam emitted by the laser is shaped by a collimating lens to form a preset field of view angle, where the field of view angle depends on the focal length of the collimating lens and the size of the laser's light-emitting surface or the total size of the laser array arrangement. In addition, the aspect ratio of the laser's light-emitting surface size or the aspect ratio of the total size of the laser array arrangement will affect the ratio of the field of view angle components in the horizontal and vertical directions formed by the detection beam, that is, the collimating lens cannot adjust the ratio of the field of view angle in the horizontal and vertical directions caused by the light-emitting size of the laser or the laser array.

[0003] Figure 1 The figure shows the correspondence between the laser radar transmitter and the output field of view. After passing through the collimating lens, the detection beam emitted by the transmitter forms a preset field of view. The size of the light-emitting surface of the transmitter is a*b (where a is the size along the vertical direction in the figure, and b is the size along the horizontal direction in the figure). After passing through the collimating lens, the vertical field of view (FOV V ) satisfies the following formula:

[0004] FOV V =2*arctan(a / 2f);

[0005] Where f is the focal length of the collimating lens. The horizontal field of view (FOV H ) satisfies the following formula:

[0006] FOV H =2*arctan(b / 2f);

[0007] The vertical and horizontal dimensions can be formed by a single laser (emitting unit) or by an array of lasers (emitting units). According to the above formula, the field of view of the laser (array) emitted light is related to its own luminous size. The vertical field of view FOV V Horizontal field of view FOV H The ratio is equivalent to the ratio of the vertical and horizontal luminous sizes of the laser (array) (without considering lens distortion). For example, when the vertical luminous size of the laser (array) is close to the horizontal luminous size, the vertical field of view FOV VHorizontal field of view FOV H At present, due to the limitation of process level, the yield of VCSEL laser or array with vertical luminous size / horizontal luminous size (or horizontal luminous size / vertical luminous size) above 3 is difficult to guarantee. Therefore, when using laser array, FOV H / FOV V It is difficult to have a larger ratio, which is disadvantageous in some occasions. For example, for the application of LiDAR, the range of the central small vertical field of view and large horizontal field of view (such as FOV H / FOV V >5), which is impossible to achieve with traditional methods. Compared with array lasers cut directly from wafers, the arrangement size of multiple discretely packaged VCSELs arranged in an array with a relatively large aspect ratio will be significantly larger, which is not conducive to the miniaturization of LiDAR. In addition, since there are gaps when discrete devices are mounted, and the proportion of the light-emitting surface of discrete devices to the entire device surface is limited, the light spot within the field of view cannot be completely covered, which is not conducive to detection.

[0008] In addition, the energy distribution in different areas of the field of view depends on the luminous density of the laser and the optical efficiency of the lens at the corresponding position. The existing technology cannot achieve sufficient control freedom.

[0009] The contents of the background technology section are merely the technologies known to the inventors and do not necessarily represent the prior art in the field. Summary of the invention

[0010] In view of one or more defects in the prior art, the present invention provides a design method for a transmitting optical component for a laser radar, wherein the transmitting optical component includes a metasurface lens, and the design method includes:

[0011] Obtaining parameters of the transmitting device of the laser radar;

[0012] Obtaining parameters of the target field of view of the laser radar;

[0013] The metasurface lens is designed according to the parameters of the transmitting device and the parameters of the target field of view, so that the detection light beam emitted by the transmitting device can obtain the target field of view after passing through the metasurface lens.

[0014] According to one aspect of the present invention, the parameters of the emitting device include the size parameters of the light-emitting surface of the emitting device and / or the distance between the light-emitting surface and the metasurface lens; the parameters of the target field of view include the aspect ratio of the target field of view and / or the energy distribution in the target field of view.

[0015] According to one aspect of the present invention, wherein the transmitting device includes a plurality of light-emitting units, the step of designing a metasurface lens includes: designing a plurality of microstructure partitions, wherein the microstructure partitions correspond one-to-one to the light-emitting units, and each of the microstructure partitions is configured to individually modulate the light beam emitted by the corresponding light-emitting unit, and project it to the outside of the laser radar to cover a sub-field of view, and the plurality of sub-fields of view are combined to form a target field of view of the laser radar.

[0016] According to one aspect of the present invention, the aspect ratio of the sub-field of view is greater than the aspect ratio of the light-emitting surface of the light-emitting unit corresponding to the sub-field of view; the aspect ratio of the target field of view is greater than the aspect ratio of the light-emitting surface of the emitting device.

[0017] According to one aspect of the present invention, the aspect ratio of at least some of the multiple sub-fields of view is greater than 3, preferably greater than 5.

[0018] According to one aspect of the present invention, the sub-fields of view corresponding to the multiple light-emitting units are substantially consistent, and the arrangement of the sub-fields of view corresponding to the multiple light-emitting units is consistent with the arrangement of the multiple light-emitting units.

[0019] According to one aspect of the present invention, the sub-field of view ranges corresponding to the multiple light-emitting units are inconsistent; within the target field of view of the laser radar, the sub-field of view close to the center area is smaller than the sub-field of view close to the edge area, so as to increase the power density within the sub-field of view close to the center area.

[0020] According to one aspect of the present invention, the present invention also includes a light transmitting module for a laser radar, the light transmitting module comprising:

[0021] An emitting device, the emitting device comprising a plurality of light-emitting units;

[0022] A metasurface lens, wherein the metasurface lens is arranged downstream of the optical path of the transmitting device, and the metasurface lens is divided into a plurality of microstructure partitions; each of the microstructure partitions corresponds to a light-emitting unit, and each of the microstructure partitions is configured to individually modulate the light beam emitted by the corresponding light-emitting unit, and project it to the outside of the laser radar to cover a sub-field of view, and a plurality of sub-fields of view are combined to form a target field of view of the laser radar.

[0023] According to one aspect of the present invention, the microstructure partitions have columnar microstructures; the design parameters of the microstructure in each of the microstructure partitions are determined according to the parameters of the corresponding light-emitting unit and the parameters of the corresponding sub-field of view, the design parameters of the microstructure include one or more of the cross-sectional size, height, and arrangement of the microstructure, the parameters of the light-emitting unit include the size of the light-emitting surface of the light-emitting unit and / or the distance between the light-emitting surface and the metasurface lens, and the parameters of the sub-field of view include the aspect ratio and / or energy distribution of the sub-field of view.

[0024] According to one aspect of the present invention, the aspect ratio of at least some of the multiple sub-fields of view is greater than 3, preferably greater than 5.

[0025] According to one aspect of the present invention, the multiple light-emitting units are arranged in a one-dimensional array or a two-dimensional array; after the light beams emitted by the multiple light-emitting units are shaped by corresponding microstructure partitions, the multiple sub-fields of view formed are spliced ​​with each other or partially overlapped.

[0026] According to one aspect of the present invention, the sub-fields of view corresponding to the multiple light-emitting units are substantially consistent, and the arrangement of the sub-fields of view corresponding to the multiple light-emitting units is consistent with the arrangement of the multiple light-emitting units.

[0027] According to one aspect of the present invention, the sub-field of view ranges corresponding to the multiple light-emitting units are inconsistent; within the target field of view of the laser radar, the sub-field of view close to the center area is smaller than the sub-field of view close to the edge area, so as to increase the power density within the sub-field of view close to the center area.

[0028] According to one aspect of the present invention, the metasurface lens is configured to enable continuous variation of power density at different positions within the target field of view of the laser radar.

[0029] According to one aspect of the present invention, the present invention also includes a light transmitting module for a laser radar, the light transmitting module comprising:

[0030] a first launch device;

[0031] A first transmitting lens, which is disposed downstream of the optical path of the first transmitting device and is configured to project the light beam emitted by the first transmitting device to the outside of the laser radar to form a first field of view;

[0032] a second launching device; and

[0033] A second transmitting lens, which is disposed downstream of the optical path of the second transmitting device and is configured to project the light beam emitted by the second transmitting device to the outside of the laser radar to form a second field of view;

[0034] The second field of view is entirely within the first field of view, and the second emitting lens is a metasurface lens, which is configured so that the light beam emitted by the second emitting device can obtain the second field of view after passing through the metasurface lens.

[0035] According to one aspect of the present invention, the shape of the first field of view is a proportional enlargement of the shape of the light-emitting surface of the first emitting device; and the shape of the second field of view is flat.

[0036] According to one aspect of the present invention, the aspect ratio of the second field of view is greater than the aspect ratio of the light emitting surface of the second emitting device.

[0037] According to one aspect of the present invention, the aspect ratio of the second field of view is greater than 3, preferably greater than 5.

[0038] According to one aspect of the present invention, the second field of view is located in the middle of the first field of view.

[0039] According to one aspect of the present invention, the first emitting device and the second emitting device are controlled to light up successively; and the first emitting lens is a metasurface lens.

[0040] According to one aspect of the present invention, the second emitting device includes a plurality of light-emitting units, and the second emitting lens is divided into a plurality of microstructure partitions; each of the microstructure partitions corresponds to a light-emitting unit, and each of the microstructure partitions is configured to individually modulate the light beam emitted by the corresponding light-emitting unit, and project it to the outside of the laser radar to cover a sub-field of view, and a plurality of sub-fields of view are combined to form the second field of view range.

[0041] According to one aspect of the present invention, the microstructure partitions have columnar microstructures; the design parameters of the microstructure in each of the microstructure partitions are determined according to the parameters of the corresponding light-emitting unit and the parameters of the corresponding sub-field of view, the design parameters of the microstructure include one or more of the cross-sectional size, height, and arrangement of the microstructure, the parameters of the light-emitting unit include the size of the light-emitting surface of the light-emitting unit and / or the distance between the light-emitting surface and the second emitting lens, and the parameters of the sub-field of view include the aspect ratio and / or energy distribution of the sub-field of view.

[0042] According to one aspect of the present invention, the multiple light-emitting units are arranged in a one-dimensional array or a two-dimensional array; after the light beams emitted by the multiple light-emitting units are shaped by corresponding microstructure partitions, the multiple sub-fields of view formed are spliced ​​with each other or partially overlapped.

[0043] According to one aspect of the present invention, the sub-fields of view corresponding to the multiple light-emitting units are substantially consistent, and the arrangement of the sub-fields of view corresponding to the multiple light-emitting units is consistent with the arrangement of the multiple light-emitting units.

[0044] According to one aspect of the present invention, the sub-field of view ranges corresponding to the multiple light-emitting units are inconsistent; within the second field of view range, the sub-field of view close to the central area is smaller than the sub-field of view close to the edge area, so as to increase the power density within the sub-field of view range close to the central area.

[0045] According to one aspect of the present invention, the metasurface lens is configured to enable continuous variation of power density at different positions within the second field of view.

[0046] According to one aspect of the present invention, the present invention further includes a laser radar, the laser radar comprising:

[0047] The optical transmission module as described above;

[0048] A receiving unit, the receiving unit comprising:

[0049] a receiving lens, the receiving lens receiving the echo of the detection light beam emitted by the optical transmission module on the obstacle and guiding the echo to the detector; and

[0050] A detector receives the echo and converts the echo into an electrical signal.

[0051] According to one aspect of the present invention, the receiving lens is a metasurface lens, and the detector is a single photon avalanche diode (SPAD) array.

[0052] Compared with the prior art, an embodiment of the present invention provides a design method for an emitting optical component for a laser radar, wherein the emitting optical component includes a metasurface lens, and the metasurface lens is designed according to the parameters of the laser radar's emitting device and the parameters of the target field of view. The metasurface lens can be used to form a desired target field of view, greatly enriching the selectable range of the laser radar's output field of view, meeting the laser radar's field of view requirements in different scenarios, reducing the processing requirements for the emitting device, and avoiding the use of discretely packaged lasers, which is conducive to the miniaturization of the laser radar.

[0053] The present invention also includes an embodiment of an optical transmission module for a laser radar, which utilizes a metasurface lens in conjunction with a transmitting device to form a preset target field of view, wherein multiple microstructure partitions in the metasurface lens correspond to multiple light-emitting units in the transmitting device, and light beams emitted by the light-emitting units are modulated individually and projected to the outside of the laser radar to cover a sub-field of view, and multiple sub-fields of view are ultimately combined into a target field of view, which can enable different positions in the target field of view of the laser radar to exhibit different field of view and power density characteristics, thereby meeting the field of view requirements of the laser radar in different application scenarios.

[0054] The present invention also includes another embodiment of an optical transmitting module for a laser radar, which has two groups of transmitting devices and their corresponding transmitting lenses, and uses a metasurface lens to form a second field of view within the first field of view. For specific applications of the laser radar, an area with more information of interest is set as an area covered by the second field of view. Within the field of view of the laser radar, the detection results within the second field of view can be enhanced, thereby further improving the detection accuracy and ranging capability of the laser radar.

[0055] The present invention also includes an embodiment of a laser radar. The application of the optical transmission module described in the above embodiment can optimize the laser radar's output field of view, adapt to the specific application scenarios of the laser radar, reduce the requirements for the transmitting device, and improve the detection accuracy of the laser radar. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0057] Figure 1 It is a schematic diagram of the corresponding relationship between the transmitting device and the output field of view in the laser radar;

[0058] Figure 2 is a schematic flow chart of a design method for a transmitting optical component of a laser radar in one embodiment of the present invention;

[0059] Figure 3 is a schematic diagram of a metasurface lens in one embodiment of the present invention;

[0060] Figure 4A and 4B is a schematic diagram of a light emitting unit according to different embodiments of the present invention;

[0061] Figure 5 is a schematic diagram of a light transmitting module for a laser radar in one embodiment of the present invention;

[0062] Figure 6A-6C is a schematic diagram of the correspondence between the light-emitting unit and the sub-field of view in different embodiments of the present invention;

[0063] Figure 7 The present invention Figure 6C Schematic diagram of the output field of view of the corresponding embodiment;

[0064] Figure 8 The present invention Figure 7 Schematic diagram of power density of the output field of view in one dimension of the corresponding embodiment

[0065] Fig. 9 is a schematic diagram of power density of an exit field of view in one dimension in another embodiment of the present invention;

[0066] Fig.10 is a schematic diagram of a light transmitting module for a laser radar in another embodiment of the present invention;

[0067] Fig.11 is a schematic diagram of a first field of view range and a second field of view range in one embodiment of the present invention;

[0068] Fig.12 It is a schematic diagram of the optical path of a laser radar in one embodiment of the present invention. DETAILED DESCRIPTION

[0069] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0070] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0071] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0072] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0073] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplicity and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0074] The embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0075] An embodiment of the present invention provides a design method for a transmitting optical component for a laser radar, wherein the transmitting optical component includes a metasurface lens, and the design method includes:

[0076] Obtaining parameters of the transmitting device of the laser radar;

[0077] Obtaining parameters of the target field of view of the laser radar;

[0078] The metasurface lens is designed according to the parameters of the transmitting device and the parameters of the target field of view, so that the detection light beam emitted by the transmitting device can obtain the target field of view after passing through the metasurface lens.

[0079] Figure 2 The specific process of a design method 100 for a transmitting optical component for a laser radar according to an embodiment of the present invention is shown, wherein the transmitting optical component has a metasurface lens, wherein the metasurface lens is arranged downstream of the transmitting device and is used to modulate and shape the detection beam emitted by the transmitting device. Figure 2 The design method 100 will be described.

[0080] like Figure 2 As shown, in step S101, the parameters of the laser radar's transmitting device are obtained. The transmitting device in the laser radar transmits a detection beam for detecting the laser radar's external environment. The detection beam is reflected by an obstacle to form an echo, which is acquired by the laser radar. The obstacle information is acquired based on the echo to complete the detection process. The transmitting device includes, for example, an independent laser (e.g., a laser with only one light-emitting partition), or an array of discrete lasers, or an array laser cut directly from a wafer (including multiple light-emitting partitions).

[0081] According to a preferred embodiment of the present invention, the parameters of the emitting device may be, for example, the size of the emitting surface of the emitting device and / or the distance between the emitting surface and the metasurface lens. The size of the emitting surface of the emitting device is determined according to the emitting device. For example, if the emitting device is an independent laser, the size of its emitting surface is the size of the emitting surface of the laser. If the emitting device is an array of multiple discrete lasers or an array laser cut directly from a wafer, the size of the emitting surface is the total size of the laser array or the arrangement of the emitting surface of the array laser.

[0082] In step S102, the parameters of the target field of view of the laser radar are obtained. The parameters of the target field of view of the laser radar include, for example, the aspect ratio of the target field of view and / or the energy distribution in the target field of view. The target field of view of the laser mine is determined according to the specific application requirements or design requirements of the laser radar. For example, for the laser radar used for assisted driving, its function is to obtain obstacle information in the surrounding environment of the vehicle. For the vehicle-mounted laser radar, considering the installation height of the laser radar, pedestrians, vehicles, etc. are usually located in the smaller vertical field of view in front of the laser radar, so special attention is paid to the strip field of view that is longer in the horizontal direction and narrower in the vertical direction. The use of a metasurface lens to modulate the light beam emitted by the laser and adjust the field of view of the laser radar to correspond to the application scenario can improve the detection accuracy of the laser radar, and at the same time avoid using a discretely packaged laser to form a corresponding field of view, which is conducive to miniaturizing the laser radar, reducing the processing requirements for the launch device and reducing the production cost of the laser mine. In addition, for some specific field of view areas, it is necessary to increase the energy density of the emitted detection beam, so that the echo generated by the detection echo is stronger and obstacles can be accurately detected.

[0083] The detection beam emitted by the laser radar has a certain divergence angle to cover the target field of view. The target field of view of the laser radar is a spatial concept, which can be described by the divergence angle or expressed by its aspect ratio. The aspect ratio of the target field of view represents the ratio of the dimensions in two mutually perpendicular directions in the illumination range formed by the target field of view in the plane perpendicular to the optical axis of the field of view. For example, the illumination range of the laser radar in the plane perpendicular to the optical axis of the field of view is a rectangle. The aspect ratio of the target field of view represents the ratio of the horizontal dimension to the vertical dimension of the rectangle, where the optical axis of the field of view is the direction of the center position within the target field of view (it can also be understood as the optical axis direction of the laser radar's output optical lens). Of course, if the illumination range of the target field of view is an ellipse, its aspect ratio can be the ratio of the major axis to the minor axis.

[0084] In different embodiments of the present invention, the order of step S101 and step S102 is not limited to Figure 2 The sequence shown in the figure can be performed in any order or simultaneously.

[0085] In step S103, a metasurface lens is designed according to the parameters of the transmitting device and the parameters of the target field of view, so that the detection beam emitted by the transmitting device can obtain the target field of view after passing through the metasurface lens. The metasurface lens is an optical element with a microstructure on the surface, such as a sub-wavelength-scale microstructure formed on the surface of a substrate. The microstructure may include a columnar structure with a circular, rectangular, square, or other cross-section, which can perform corresponding phase modulation on the incident light beam to change the optical properties of the incident light to form an outgoing light that meets the target field of view. Figure 3A metasurface lens according to one embodiment is shown, in which regularly distributed cylindrical nano-microstructures are formed above a substrate.

[0086] Metasurface lenses have a large degree of design freedom. The required metasurface lenses can be designed according to the parameters of the launch device and the parameters of the target field of view. Surface microstructures with different parameters (including the diameter, side length, height, arrangement, etc. of the microstructures) can be designed corresponding to different field of view areas, thereby achieving fields of view with different aspect ratios and different energy distributions.

[0087] In this embodiment, a metasurface lens is designed based on the parameters of the laser radar transmitting device and the parameters of the target field of view. The metasurface lens can be used to modulate the detection light beam emitted by the transmitting device, providing greater freedom in terms of the range of the target field of view and the power density distribution in the field of view. Targeted design can be made according to the specific needs of the laser radar, while reducing the requirements for the process and size of the transmitting device.

[0088] According to a preferred embodiment of the present invention, when designing a metasurface lens, multiple microstructure partitions are designed and correspond one-to-one to multiple light-emitting units in the emitting device.

[0089] The transmitting device of the laser radar may include multiple light-emitting units. The transmitting device is, for example, a large-sized array-type VCSEL laser, which can be individually controlled to light up in different areas. Each area (each sub-laser) includes multiple light-emitting points that can emit light simultaneously, and each area constitutes a light-emitting unit. The entire VCSEL laser can also be uniformly controlled to be turned on and off. Figure 4A It is shown that the light-emitting point on a VCSEL laser constitutes a light-emitting unit. Figure 4B It is shown that the light-emitting points on a VCSEL laser constitute two light-emitting units, wherein half of the light-emitting points on the left constitute one light-emitting unit, and half of the light-emitting points on the right constitute another light-emitting unit, the light-emitting points in the left area emit light at the same time, and the light-emitting points in the right area emit light at the same time, and the left area and the right area can be controlled to light up separately. In addition, optionally, the laser (or array) is not limited to the VCSEL laser (or array), and can also be other types of surface light-emitting devices.

[0090] Correspondingly, the metasurface lens includes multiple microstructure partitions, and the microstructure partitions correspond one to one with the light-emitting units. In this embodiment, the microstructure of the metasurface lens has multiple microstructure partitions, and one microstructure partition corresponds to one light-emitting unit. That is, the detection beam emitted by a light-emitting unit covers the corresponding microstructure partition, and the microstructure partition can be modulated separately for the beam emitted by the corresponding light-emitting unit, and the beam emitted by the light-emitting unit is projected to the outside of the laser radar to cover a sub-field of view. And multiple sub-fields of view are combined to form the target field of view of the laser radar.

[0091] Specifically, for a light-emitting unit, the light beam emitted by it forms a sub-field of view in the target field of view after passing through the metasurface lens. Multiple light-emitting units form multiple sub-fields of view correspondingly, and multiple sub-fields of view are combined to form a complete target field of view of the laser radar. It can be understood that in the target field of view of the laser radar, the optical characteristics of each sub-field of view can correspond to one of the light-emitting units and microstructure partitions, that is, each sub-field of view can be obtained by targeted design of the light-emitting unit and / or microstructure partition, and multiple sub-fields of view are spliced ​​to form a complete target field of view, so that the design flexibility of the target field of view is higher, which is conducive to the laser radar to meet different application requirements. For example, the power density of some areas in the target field of view can be increased, and the distance measurement capability of the laser radar in a specific detection direction can be improved. In the prior art, the preset target field of view is usually achieved by changing the design of the light-emitting unit in the transmitting device, but in some cases it is difficult, such as it is difficult to realize a flat, small-sized light-emitting unit. In this embodiment, the corresponding sub-field of view is obtained by designing the microstructure partition, which can improve the design freedom of the target field of view and reduce the difficulty of designing and manufacturing the light-emitting unit.

[0092] In a specific embodiment of the present invention, the aspect ratio of the sub-field of view is greater than the aspect ratio of the light-emitting surface of the light-emitting unit corresponding to the sub-field of view, and the aspect ratio of the target field of view formed by combining multiple sub-fields of view is greater than the aspect ratio of the light-emitting surface of the emitting device. Figure 6B As shown schematically, the emitting device 11 includes nine light emitting units 111 arranged in a 3*3 array, and each light emitting unit 111 includes nine light emitting points, forming a substantially square light emitting surface. Figure 6B As shown, the detection beam emitted by the transmitting device 11 forms a target field of view 13 after passing through the metasurface lens. The target field of view 13 also includes nine sub-fields of view 131, which correspond to the nine light-emitting units 111, respectively. Compared with the square light-emitting unit 111, the sub-field of view 131 has a flat shape, that is, the aspect ratio of the sub-field of view 131 is greater than the aspect ratio of the light-emitting surface of the light-emitting unit 111 corresponding to the sub-field of view. And the aspect ratio of the target field of view 13 obtained by splicing is greater than the aspect ratio of the light-emitting surface of the light-emitting device 11.

[0093] exist Figure 6BIn the embodiment, the light-emitting surface of the light-emitting unit or the light-emitting surface of the transmitting device is approximately square in shape (the square shape has low processing difficulty and high yield rate). After modulation by the metasurface lens, the sub-field of view corresponding to the light-emitting unit is a rectangle with a relatively large length and width, and the target field of view corresponding to the transmitting device can also form a rectangle with a relatively large length and width. The transmitting optical component designed according to this embodiment can be used in an on-board laser radar to detect the vehicle within a large field of view in the horizontal direction, while the detection range in the vertical direction only retains a narrow (middle) field of view to meet the use requirements, that is, the energy of the detection beam is concentrated in the effective area, the energy utilization rate is improved, and the internal structural design of the laser radar can be optimized, the requirements for the transmitting device are reduced, and the production and processing costs are reduced.

[0094] Further, according to a preferred embodiment of the present invention, Figure 6B The aspect ratio of at least some of the multiple sub-fields of view 131 shown is greater than 3, preferably greater than 5, for example, the sub-fields of view form a strip-shaped illumination range. In the target field of view, all of the sub-fields of view may have a larger aspect ratio, and the target field of view finally combined also has a larger aspect ratio.

[0095] In some embodiments of the present invention, the sub-fields of view corresponding to the multiple light-emitting units are substantially the same, and the arrangement of the sub-fields of view corresponding to the multiple light-emitting units is consistent with the arrangement of the light-emitting units in the emitting device. Figure 6B As shown, for example, the transmitting device has 9 light-emitting units 111 arranged in a 3*3 array, and the target field of view 13 formed by it also includes 9 sub-fields of view 131 arranged in a 3*3 array, and the relative positions correspond, that is, the sub-field of view corresponding to the light-emitting unit located in the upper left corner is also located in the upper left corner in the target field of view. In addition, each sub-field of view 131 is basically consistent, that is, the dimensions along the horizontal and vertical directions are basically the same. Alternatively, the arrangement of the sub-fields of view corresponding to the multiple light-emitting units and the arrangement of the light-emitting units in the transmitting device can be mirrored. Specifically, the sub-field of view corresponding to the light-emitting unit located in the upper left corner is located in the lower right corner in the target field of view.

[0096] According to some other embodiments of the present invention, the sub-field of view ranges corresponding to multiple light-emitting units are inconsistent. Specifically, for example, in the target field of view of the laser radar, the sub-field of view close to the center area is smaller than the sub-field of view close to the edge area, so as to increase the power density within the sub-field of view close to the center area. Figure 6C , an embodiment is shown in FIG. 1 , wherein in the target field of view 13 , the horizontal dimensions of the three sub-fields of view 131 close to the center are smaller than the horizontal dimensions of the sub-fields of view 131 on both sides thereof.

[0097] Among the multiple sub-fields of view of the target field of view, some sub-fields of view may have a larger aspect ratio, while other sub-fields of view may have a smaller aspect ratio (for example, the same aspect ratio as the light-emitting surface of the light-emitting unit). When the luminous power of the light-emitting units corresponding to sub-fields of view of different sizes is the same, the power density in the sub-field of view with a smaller size is greater. According to the application requirements of the laser radar, this part of the sub-field of view with a smaller size in the target field of view can be set as the area of ​​interest to obtain a more accurate, precise or longer detection range. In specific applications, the area of ​​interest is usually located in the center of the target field of view. For example, the target field of view is a rectangular range, and the central area can be the central area of ​​the long side, the central area of ​​the short side, or the central area of ​​the entire rectangular range. The specific design is based on actual needs.

[0098] like Figure 5 As shown, the present invention also relates to an optical transmitting module 10 for a laser radar, the optical transmitting module 10 includes a transmitting device 11 and a metasurface lens 12, the transmitting device 11 includes a plurality of light emitting units 111, and the plurality of light emitting units 111 can be arranged in a one-dimensional or two-dimensional array in the transmitting device 11. Figure 5 FIG. 1 shows a case where a plurality of light emitting units 111 are arranged in one direction in the emitting device 11. Of course, Figure 5 Multiple rows of light-emitting units 111 may also be arranged in the direction of the paper to form a two-dimensional array.

[0099] The metasurface lens 12 is arranged downstream of the optical path of the emitting device 11, wherein the metasurface lens 12 is divided into a plurality of microstructure partitions ( Figure 5 Each microstructure partition corresponds to a light emitting unit 111, and each microstructure partition is used to modulate the light beam emitted by the corresponding light emitting unit 111 separately, and project it to the outside of the laser radar to cover a sub-field of view 131, such as Figure 5 As shown in FIG. 1 , a plurality of sub-fields of view 131 are combined to form a target field of view 13 of the laser radar.

[0100] The multiple light-emitting units 111 in the emitting device 11 may be different partitions of the multiple light-emitting points in the emitting device 11, or may be multiple discrete lasers, for example, the emitting device 11 is an array of discrete lasers, or an array laser cut directly from a wafer. Specifically, the emitting device 11 is, for example, a large-sized array-type VCSEL laser, which can be controlled to light up separately in different areas, each area (each sub-laser) includes multiple light-emitting points that can emit light at the same time, and each area constitutes a light-emitting unit 111; the entire VCSEL laser can also be uniformly controlled to be turned on and off. Figure 4BIt is shown that the light-emitting points on an arrayed VCSEL laser constitute two light-emitting units, wherein half of the light-emitting points on the left constitute one light-emitting unit, and half of the light-emitting points on the right constitute another light-emitting unit, the light-emitting points in the left area emit light at the same time, and the light-emitting points in the right area emit light at the same time, and the left area and the right area can be controlled to light up separately. In addition, optionally, the laser (or array) is not limited to the VCSEL laser (or array), and can also be other types of surface light-emitting devices.

[0101] The multiple microstructure partitions of the metasurface lens 12 can be obtained, for example, according to the parameters of the corresponding light-emitting unit 111 and the parameter design of the sub-field of view formed by the light-emitting unit 111. The microstructure partitions in this embodiment individually modulate the light-emitting unit 111, and the sub-fields of view 131 corresponding to different light-emitting units 111 can have different optical characteristics, so that the target field of view is not limited to the uniformly distributed field of view, and can be adjusted for specific application scenarios, thereby improving the matching degree between the laser radar and the application scenario. In addition, this embodiment uses the metasurface lens 12 to form the target field of view 13, which reduces the requirements for the transmitting device 11, is conducive to optimizing the structure of the internal components of the laser radar, and reduces the processing difficulty and production cost.

[0102] According to a preferred embodiment of the present invention, the microstructure partition in the metasurface lens 12 has a microstructure, for example Figure 3 As shown. The design parameters of the microstructure are determined according to the parameters of the corresponding light-emitting unit 111 and the parameters of the corresponding sub-field of view 131. Specifically, the design parameters of the microstructure include one or more of the cross-sectional size, height, and arrangement of the microstructure. The parameters of the light-emitting unit 111 include the size of the light-emitting surface of the light-emitting unit 111 and / or the distance between the light-emitting surface of the light-emitting unit 111 and the metasurface lens 12. The parameters of the sub-field of view 131 include the aspect ratio and / or energy distribution of the sub-field of view 131.

[0103] The microstructure partitions in this embodiment match the corresponding light-emitting units 111 and sub-fields of view 131. The sizes of the multiple light-emitting units 111 in the emitting device 11 can be the same or different, preferably the same, to reduce the difficulty of processing. The design parameters of the microstructures in the microstructure partitions are obtained according to the corresponding light-emitting units 111 and the corresponding sub-fields of view 131, and the metasurface lens 12 can be obtained by combining the multiple microstructure partitions.

[0104] Figure 6A-6C The diagram shows the correspondence between the light emitting unit 111 and the sub-field of view 131 in different embodiments of the present invention, and the difference between the sub-field of view 131 in different embodiments.

[0105] like Fig. 6AAs shown, the light-emitting units 111 in the emitting device 11 are arranged in a 3*3 array, wherein the light-emitting surface size of each light-emitting unit 111 is approximately square. Fig. 6A Each light-emitting unit 111 includes 9 laser light-emitting points. In different embodiments of the present invention, the light-emitting units 111 may also be laser light-emitting points of other numbers or other arrangements. After the detection light beam emitted by the light-emitting unit 111 passes through the metasurface lens 12, the target field of view 13 formed also includes 9 sub-fields of view 131, and the shape, size, power density distribution, etc. of each sub-field of view 131 are basically the same. At the same time, the arrangement position of each sub-field of view 131 in the target field of view 13 matches the arrangement position of the corresponding light-emitting unit 111 in the transmitting device 11, that is, the light beams emitted from the metasurface lens 12 avoid crossing, and the light beams emitted by multiple light-emitting units 111 extend in different directions and are combined into the target field of view 13. In this embodiment, the aspect ratio of the sub-field of view 131 is basically the same as the aspect ratio of the light-emitting unit 111.

[0106] like Figure 6B As shown, in another embodiment of the present invention, the transmitting device 11 can be configured to Fig. 6A The embodiment shown in is the same as that shown in , and after being modulated by the metasurface lens 12, the sub-field of view 131 corresponding to each light-emitting unit 111 is also basically the same, and the arrangement of the sub-field of view 131 corresponding to the multiple light-emitting units 111 is consistent with the arrangement of the multiple light-emitting units 111. However, in this embodiment, the light-emitting unit 111 with a roughly square light-emitting surface is modulated by the corresponding microstructure partition to form a long strip of flat sub-field of view 131, and the long strip of sub-field of view 131 is combined to form a long strip of target field of view 13. Furthermore, the aspect ratio of the multiple sub-fields of view 131 in the target field of view 13 is preferably greater than 3; more preferably, the aspect ratio of the sub-field of view 131 is greater than 5. The light emitting module 10 in this embodiment can form a long strip of target field of view 13, which is suitable for use in vehicle-mounted laser radars and can cover the detection range required by the vehicle-mounted laser radar during use.

[0107] like Figure 6C As shown, according to a preferred embodiment of the present invention, the configuration of the emitting device 11 can be the same as the above embodiment. After passing through the metasurface lens 12, under the modulation of the corresponding microstructure partition, the light emitting unit 111 forms Figure 6C In the target field of view 13 shown, the sub-fields of view 131 are long strips, and their aspect ratio is greater than 3, preferably greater than 5. The combined target field of view 13 is also long strips. In the target field of view 13, the shapes and sizes of the multiple sub-fields of view 131 are different, and the size of the sub-field of view 131 near the center area is smaller than the size of the sub-field of view 131 near the edge area. Specifically, Figure 6CAs shown, the length of the sub-field of view 131 located at the horizontal center position of the target field of view 13 is smaller than the length of the sub-field of view 131 at the edge position, and the width of the sub-field of view 131 located at the vertical center position of the target field of view 13 can also be set to be smaller than the width of the sub-field of view 131 at the edge position, or in the target field of view 13 formed, the length and width of the sub-field of view 131 at the center position are both smaller than the length and width of the sub-field of view 131 at the edge position.

[0108] Figure 7 Shows Figure 6C The schematic diagram of the emitting device 11 of the embodiment shown in FIG. Figure 7 As shown, after modulation by the metasurface lens 12, the diffusion angle of the sub-field of view 131 corresponding to the light-emitting unit 111 at the edge position can be greater than the diffusion angle of the sub-field of view 131 corresponding to the light-emitting unit 111 at the center position. When the specifications of the light-emitting unit 111 at the edge position and the light-emitting unit 111 at the center position are the same or similar, the power density within the sub-field of view 131 close to the center area can be increased. Figure 8 As shown, the light spot within the sub-field of view 131 close to the central area is smaller and has a higher power density, thereby improving the detection accuracy and ranging capability of the laser radar in the area.

[0109] Further, according to a preferred embodiment of the present invention, by designing the microstructure in the metasurface lens 12, the power density at different positions in the target field of view 13 of the laser radar can be continuously changed, such as Fig. 9 As shown, the microstructure partitions in the metasurface lens 12 can be optimized so that the power densities of the corresponding sub-fields of view 131 are different (the sub-fields of view 131 have different shapes and sizes) and the power density changes continuously. The power density distribution in the target field of view 13 gradually decreases from the center position to the edge position, thereby avoiding or reducing sudden changes in power density and improving the accuracy of radar detection.

[0110] Fig.10 The specific structure of a light transmitting module 20 for laser radar according to another embodiment of the present invention is shown. Fig.11 The relationship between the first field of view and the second field of view is shown below. Fig.10 and Fig.11 Expand on it.

[0111] The optical transmission module 20 includes a first transmitting device 21, a first transmitting lens 22, a second transmitting device 23 and a second transmitting lens 24, wherein the first transmitting device 21 and the second transmitting device 23 can both emit detection light beams, such as a laser or a laser array, and the first transmitting device 21 and the second transmitting device 23 can be individually controlled to light up and shut down.

[0112] like Fig.10 As shown, the first emitting lens 22 is arranged downstream of the optical path of the first emitting device 21, and the first emitting lens 22 is arranged to project the light beam emitted by the first emitting device 21 to the outside of the laser radar to form a first field of view range 25 (such as Fig.11 shown).

[0113] The second emitting lens 24 is arranged downstream of the optical path of the second emitting device 23, and the second emitting lens 24 is arranged to project the light beam emitted by the second emitting device 23 to the outside of the laser radar to form a second field of view range 26 (such as Fig.11 shown).

[0114] In this embodiment, the second field of view 26 is entirely within the first field of view 25, and the second emitting lens 24 is a metasurface lens, such as the metasurface lens in the aforementioned embodiment, wherein the surface microstructure of the metasurface lens is configured to obtain the second field of view 26 after the light beam emitted by the second emitting device 23 is modulated by the microstructure. In a specific embodiment, the first emitting lens 22 may be a conventional lens, for example, forming a field of view with a smaller aspect ratio, or forming a field of view that is proportional to the size of the light emitting surface of the first emitting device 21.

[0115] In this embodiment, the second field of view 26 is not larger than the first field of view 25. The second field of view 26 can focus on detecting a part of the area within the first field of view 25, that is, the second field of view 26 is regarded as an area of ​​interest within the first field of view 25, preferably an area close to the center of the first field of view 25. Fig.11 shown.

[0116] The process of forming the first field of view 25 using the first emitting device 21 and the first emitting lens 22, and the process of forming the second field of view 26 using the second emitting device 23 and the second emitting lens 24, are preferably performed at intervals, for example, the first field of view 25 is formed first, then the first emitting device 21 is turned off, and the second emitting device 23 is turned on to form the second field of view, so as to reduce the risk of crosstalk. In different embodiments of the present invention, the detection order of the first field of view 25 and the second field of view 26 can be opposite, without additional restrictions.

[0117] The shape ratios of the second field of view range 26 and the first field of view range 25 are preferably different, for example Fig.11The aspect ratio (ratio of the long side to the short side) of the second field of view 26 shown in FIG. 2 is greater than the aspect ratio of the first field of view 25. According to a preferred embodiment of the present invention, the first field of view 25 is a proportional enlargement of the light-emitting surface of the first transmitting device 21. For example, the first transmitting device 21 and the first transmitting lens 22 adopt the design of a conventional laser radar transmitting end, and the shape of the field of view is not adjusted to obtain a larger detection range. The second field of view 26 is adjusted to Fig.11 The flat shape shown in the figure is used to focus on improving the detection accuracy within the strip range.

[0118] In different embodiments of the present invention, the second field of view range 26 may also be in other shapes, or be located at other positions of the first field of view range 25 to meet the use requirements of the laser radar in different scenarios.

[0119] Further, according to a preferred embodiment of the present invention, the aspect ratio of the second field of view 26 is greater than the aspect ratio of the light-emitting surface of the second emitting device 23. This embodiment uses a metasurface lens to adjust the shape of the second field of view 26 to better meet the use requirements of the laser radar, for example, to form a flat second field of view 26 so that the light emitting module 20 is suitable for a vehicle-mounted laser radar. Specifically, the aspect ratio of the second field of view 26 is greater than 3, preferably greater than 5.

[0120] Preferably, the second transmitting device 23 can be configured to have the same specifications as the first transmitting device 21, so as to reduce the types of accessories required by the laser radar in production and processing, and the power density in the second field of view range 26 is greater than the power density in the first field of view range 25, so as to detect the area of ​​interest with higher accuracy. In a preferred embodiment of the present invention, the first transmitting lens 22 can also be a metasurface lens, which has the advantages of small size, light weight, and higher flexibility in light beam modulation, and can also be used to project the light beam emitted by the first transmitting device 21 into a preset first field of view range 25.

[0121] According to a preferred embodiment of the present invention, specifically as described in the aforementioned embodiment, the second emitting device 23 includes a plurality of light-emitting units, the second emitting lens 24 is divided into a plurality of microstructure partitions, and each microstructure partition corresponds to a light-emitting unit, and is configured to separately modulate the detection light beam emitted by the corresponding light-emitting unit, and project the modulated light beam to the outside of the laser radar to cover a sub-field of view, and the sub-fields of view corresponding to the plurality of light-emitting units are combined to form a second field of view range 26.

[0122] Furthermore, in a preferred embodiment, a columnar microstructure is provided in the microstructure partition. The design parameters of the microstructure in each microstructure partition are determined according to the parameters of the corresponding light-emitting unit and the parameters of the corresponding sub-field of view, and the design parameters of the microstructure include one or more of the cross-sectional size, height, and arrangement of the microstructure. The parameters of the light-emitting unit include the size of the light-emitting surface of the light-emitting unit and / or the distance between the light-emitting surface and the second emitting lens. The parameters of the sub-field of view include the aspect ratio and / or energy distribution of the sub-field of view. Please refer to the aforementioned embodiments for details, which will not be repeated here.

[0123] Similarly, in the optical transmitter module 20, the plurality of light-emitting units in the second transmitter 23 are arranged in a one-dimensional array or a two-dimensional array. After the light beams emitted by the plurality of light-emitting units are shaped by the corresponding microstructure partitions in the second transmitter lens 24, the plurality of sub-fields of view formed are spliced ​​or partially overlapped with each other to form a second field of view range 26.

[0124] In different embodiments of the present invention, the sub-fields of view corresponding to the multiple light-emitting units in the second emitting device 23 in the second field of view range 26 may be basically consistent, or may have different shapes and sizes. The arrangement of the sub-fields of view corresponding to the multiple light-emitting units in the second field of view range 26 is consistent with the arrangement of the multiple light-emitting units in the second light-emitting device 23, which is specifically the same as the aforementioned embodiment.

[0125] In the second field of view 26, the metasurface lens can also be used to make the sub-field of view near the central area smaller than the sub-field of view near the edge area, so as to increase the power density in the sub-field of view near the central area, further forming an area with higher detection accuracy and stronger distance measurement capability in the second field of view 26, and improving the performance of the laser mine. Similarly, the second emitting lens 24 can be set to enable the power density at different positions in the second field of view 26 to change continuously by designing the microstructure in the microstructure partition.

[0126] like Fig.12 As shown, the present invention also includes an embodiment of a laser radar 1, the laser radar 1 includes the above reference Figure 5-Figure 11 The described optical transmitting module 2 and receiving unit 3, wherein the receiving unit 3 includes a receiving lens 31 and a detector 32, wherein the receiving lens 31 is used to receive the echo of the detection light beam emitted by the optical transmitting module 2 on the obstacle, and guide the echo to the detector 32. After receiving the echo, the detector 32 can convert the echo into an electrical signal, and the laser radar 1 can obtain the position information, reflectivity, etc. of the obstacle based on the electrical signal.

[0127] For the optical transmission module 2 having a first transmitting device and a second transmitting device, a receiving unit 3 can be provided to simultaneously obtain the echo of the detection light beam emitted by the first transmitting device and the echo of the detection light beam emitted by the second transmitting device, or two groups of receiving units 3 can be provided, corresponding to the first transmitting device and the second transmitting device, respectively. Specifically, the receiving lens 31 in the receiving unit 3 can also select a metasurface lens to reduce the volume and weight of the receiving unit 3. The detector 32 can be a single-photon detector, such as a single-photon avalanche diode (SPAD) array, and each SPAD in the SPAD array can be individually gated and activated. Alternatively, such as a silicon photomultiplier (Si PM), the detector 32 may include multiple detection units, which correspond to the light-emitting units in the optical transmission device 2 to form multiple detection channels.

[0128] Finally, it should be noted that the above description is only an embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A design method for a transmitting optical component for a laser radar, wherein the transmitting optical component includes a metasurface lens, and the design method comprises: Obtaining parameters of the transmitting device of the laser radar; Obtaining parameters of the target field of view of the laser radar; The metasurface lens is designed according to the parameters of the transmitting device and the parameters of the target field of view, so that the detection light beam emitted by the transmitting device can obtain the target field of view after passing through the metasurface lens.

2. The design method according to claim 1, wherein the parameters of the emitting device include the size parameters of the light-emitting surface of the emitting device and / or the distance between the light-emitting surface and the metasurface lens; the parameters of the target field of view include the aspect ratio of the target field of view and / or the energy distribution in the target field of view.

3. The design method according to claim 1, wherein the emitting device comprises a plurality of light-emitting units, and the step of designing the metasurface lens comprises: A plurality of microstructure partitions are designed, wherein the microstructure partitions correspond one-to-one to the light-emitting units, and each of the microstructure partitions is configured to individually modulate the light beam emitted by the corresponding light-emitting unit, and project it to the outside of the laser radar to cover a sub-field of view, and a plurality of sub-fields of view are combined to form a target field of view of the laser radar.

4. The design method according to claim 3, wherein the aspect ratio of the sub-field of view is greater than the aspect ratio of the light-emitting surface of the light-emitting unit corresponding to the sub-field of view; and the aspect ratio of the target field of view is greater than the aspect ratio of the light-emitting surface of the emitting device. 5 . The design method according to claim 3 , wherein the aspect ratio of at least some of the multiple sub-fields of view is greater than 3, preferably greater than 5.

6. The design method according to claim 3, wherein the sub-fields of view corresponding to the plurality of light-emitting units are substantially consistent, and the arrangement of the sub-fields of view corresponding to the plurality of light-emitting units is consistent with the arrangement of the plurality of light-emitting units.

7. According to the design method of claim 3, the sub-field of view ranges corresponding to the multiple light-emitting units are inconsistent; within the target field of view of the laser radar, the sub-field of view close to the center area is smaller than the sub-field of view close to the edge area, so as to increase the power density within the sub-field of view close to the center area.

8. An optical transmission module for a laser radar, comprising: An emitting device, the emitting device comprising a plurality of light-emitting units; A metasurface lens, wherein the metasurface lens is arranged downstream of the optical path of the transmitting device, and the metasurface lens is divided into a plurality of microstructure partitions; each of the microstructure partitions corresponds to a light-emitting unit, and each of the microstructure partitions is configured to individually modulate the light beam emitted by the corresponding light-emitting unit, and project it to the outside of the laser radar to cover a sub-field of view, and a plurality of sub-fields of view are combined to form a target field of view of the laser radar.

9. The optical transmission module according to claim 8, wherein the microstructure partition has a columnar microstructure; the design parameters of the microstructure in each of the microstructure partitions are determined according to the parameters of the corresponding light-emitting unit and the parameters of the corresponding sub-field of view, the design parameters of the microstructure include one or more of the cross-sectional size, height, and arrangement of the microstructure, the parameters of the light-emitting unit include the size of the light-emitting surface of the light-emitting unit and / or the distance between the light-emitting surface and the metasurface lens, and the parameters of the sub-field of view include the aspect ratio and / or energy distribution of the sub-field of view. 10 . The light emitting module according to claim 8 , wherein an aspect ratio of at least some of the plurality of sub-fields of view is greater than 3, preferably greater than 5.

11. The optical transmission module according to any one of claims 8-10, wherein the multiple light-emitting units are arranged in a one-dimensional array or a two-dimensional array; after the light beams emitted by the multiple light-emitting units are shaped by corresponding microstructure partitions, the multiple sub-fields of view formed are spliced ​​with each other or partially overlapped. 12 . The optical transmission module according to claim 11 , wherein the sub-fields of view corresponding to the plurality of light-emitting units are substantially consistent, and the arrangement of the sub-fields of view corresponding to the plurality of light-emitting units is consistent with the arrangement of the plurality of light-emitting units.

13. The optical transmission module according to claim 11, wherein the sub-field of view ranges corresponding to the multiple light-emitting units are inconsistent; within the target field of view of the laser radar, the sub-field of view close to the center area is smaller than the sub-field of view close to the edge area, so as to increase the power density within the sub-field of view close to the center area.

14. The optical transmission module according to claim 13, wherein the metasurface lens is configured to enable continuous variation of power density at different positions within the target field of view of the laser radar.

15. An optical transmission module for a laser radar, comprising: a first launch device; A first transmitting lens, which is disposed downstream of the optical path of the first transmitting device and is configured to project the light beam emitted by the first transmitting device to the outside of the laser radar to form a first field of view; a second launcher; and A second transmitting lens, which is disposed downstream of the optical path of the second transmitting device and is configured to project the light beam emitted by the second transmitting device to the outside of the laser radar to form a second field of view; The second field of view is entirely within the first field of view, and the second emitting lens is a metasurface lens, which is configured so that the light beam emitted by the second emitting device can obtain the second field of view after passing through the metasurface lens. 16 . The light emitting module according to claim 15 , wherein the shape of the first field of view is a proportional enlargement of the shape of the light emitting surface of the first emitting device; and the shape of the second field of view is flat. 17 . The light emitting module according to claim 16 , wherein an aspect ratio of the second field of view is greater than an aspect ratio of a light emitting surface of the second emitting device. 18 . The light transmitting module according to claim 16 , wherein an aspect ratio of the second field of view is greater than 3, preferably greater than 5.

19. The optical transmission module according to any one of claims 15 to 18, wherein the second field of view is located in the middle of the first field of view.

20. The light emitting module according to any one of claims 15-18, wherein the first emitting device and the second emitting device are controlled to light up successively; and the first emitting lens is a metasurface lens.

21. An optical transmission module according to any one of claims 16-18, wherein the second transmitting device comprises a plurality of light-emitting units, and the second transmitting lens is divided into a plurality of microstructure partitions; each of the microstructure partitions corresponds to a light-emitting unit, and each of the microstructure partitions is configured to individually modulate the light beam emitted by the corresponding light-emitting unit, and project it to the outside of the laser radar to cover a sub-field of view, and a plurality of sub-fields of view are combined to form the second field of view range.

22. The optical transmission module according to claim 21, wherein the microstructure partition has a columnar microstructure; the design parameters of the microstructure in each of the microstructure partitions are determined according to the parameters of the corresponding light-emitting unit and the parameters of the corresponding sub-field of view, the design parameters of the microstructure include one or more of the cross-sectional size, height, and arrangement of the microstructure, the parameters of the light-emitting unit include the size of the light-emitting surface of the light-emitting unit and / or the distance between the light-emitting surface and the second transmitting lens, and the parameters of the sub-field of view include the aspect ratio and / or energy distribution of the sub-field of view.

23. The optical transmission module according to any one of claims 21, wherein the multiple light-emitting units are arranged in a one-dimensional array or a two-dimensional array; after the light beams emitted by the multiple light-emitting units are shaped by corresponding microstructure partitions, the multiple sub-fields of view formed are spliced ​​with each other or partially overlapped. 24 . The optical transmission module according to claim 23 , wherein the sub-fields of view corresponding to the plurality of light-emitting units are substantially consistent, and the arrangement of the sub-fields of view corresponding to the plurality of light-emitting units is consistent with the arrangement of the plurality of light-emitting units.

25. The optical transmission module according to claim 23, wherein the sub-field of view ranges corresponding to the plurality of light-emitting units are inconsistent; within the second field of view range, the sub-field of view close to the central area is smaller than the sub-field of view close to the edge area, so as to increase the power density within the sub-field of view range close to the central area.

26. The light emitting module according to claim 25, wherein the metasurface lens is configured to enable continuous variation of power density at different positions within the second field of view.

27. A laser radar, comprising: The optical transmission module as claimed in any one of claims 8 to 26; A receiving unit, the receiving unit comprising: A receiving lens, which receives the echo of the detection light beam emitted by the optical transmitting module on the obstacle and guides the echo to the detector; and A detector receives the echo and converts the echo into an electrical signal.

28. The laser radar according to claim 27, wherein the receiving lens is a metasurface lens and the detector is a single photon avalanche diode (SPAD) array.

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