Optical emission module and laser radar comprising same

Abstract

The invention provides an optical emission module and a laser radar comprising the same. The optical emission module provided by the invention comprises a light source array; a super lens; the light source array comprises at least two sub-light sources which are arranged at intervals at least in the first direction of a two-dimensional plane where the light source array is located. A first distance is kept between the super lens and the light source array, so that a light beam output by the super lens is projected on a target plane to obtain a linear light spot; wherein at least one second distance different from the first distance exists, and if the second distance is kept between the super lens and the light source array, the super lens is used for collimating a light beam emitted by the light source array, so that the light beam output by the super lens is used for projecting on a target plane to obtain a light spot array; point light spots in the light spot array are at least arranged at intervals in the line length direction. According to the optical emission module provided by the invention, the phase distribution of the super lens can be designed more conveniently, that is, the light beam output by the super lens can be projected to obtain a linear light spot.

Description

Technical Field

[0001] The present application relates to the field of optics, and in particular to an optical emission module and a laser radar comprising the same. Background Art

[0002] In application scenarios such as 3D sensing, laser etching, and positioning identification, an optical emission module is usually required to emit a light beam for projecting a line spot on the target plane. Depending on the application requirements, the target plane can be a wall surface, the ground, or a face surface. When the target plane is an ideal flat surface, the line spot projected on the target plane is a straight straight line, or a straight line with a slight arc, so the line spot is usually also called a straight line spot.

[0003] In order to emit a light beam, the optical emission module needs to be equipped with a light source. At present, the common light sources in the optical field are mostly VCSEL (Vertical-Cavity Surface-Emitting Laser), EEL (Edge-Emitting Laser), LED (Light-Emitting Diode), etc., and the light beams emitted by these light sources cannot directly project a line spot. Therefore, the optical emission module also needs to be equipped with a beam shaping element, which modulates the light beam emitted by the light source so that the modulated light beam can project a line spot.

[0004] In order to reduce the volume of such optical emission modules, it is proposed in the related art that a superlens is used as a beam shaping element to modulate the light beam emitted by the light source, so that the modulated light beam can project a linear light spot. However, in order for the optical emission module provided by the related art to enable the light beam output by the superlens to project a linear light spot, it is necessary to design the phase distribution of the superlens in a relatively complex manner. Summary of the invention

[0005] One purpose of the present application is to provide an optical emission module and a laser radar including the same. The optical emission module provided by the present application can more conveniently design the phase distribution of the metalens therein, so that the light beam output by the metalens can be projected to obtain a linear light spot.

[0006] According to one aspect of an embodiment of the present application, an optical emission module is disclosed, the optical emission module comprising: a light source array; a super lens;

[0007] The light source array comprises at least two sub-light sources, and the sub-light sources are arranged at intervals along at least a first direction on the two-dimensional plane where the light source array is located;

[0008] The metalens is arranged at the light output side of the light source array, so as to modulate and output the light beam emitted by the light source array; a first distance is maintained between the metalens and the light source array, so that the light beam output by the metalens is used to project a line light spot on a target plane; the projection of the first direction on the target plane is parallel to the line length direction of the line light spot;

[0009] Among them, there is at least one second distance different from the first distance. If the second distance is maintained between the metalens and the light source array, the metalens is used to collimate the light beam emitted by the light source array, so that the light beam output by the metalens is used to project a light spot array on the target plane; the point light spots in the light spot array are arranged at intervals at least along the line length direction.

[0010] In an exemplary embodiment of the present application, in the first direction, the intervals between adjacent sub-light sources are equal;

[0011] Alternatively, in the first direction, there are at least two types of intervals between adjacent sub-light sources.

[0012] In an exemplary embodiment of the present application, the metalens is also used to replicate the line spot along the line length direction;

[0013] If the second distance is maintained between the superlens and the light source array, the number of the light spots arranged at intervals along the line length direction in the light spot array is at least twice the number of the sub-light sources arranged at intervals along the first direction.

[0014] In an exemplary embodiment of the present application, the metalens is also used to replicate the line spot along the line width direction;

[0015] If the second distance is maintained between the superlens and the light source array, the number of the light spots arranged at intervals along the line width direction in the light spot array is at least twice the number of the sub-light sources arranged along the second direction.

[0016] In an exemplary embodiment of the present application, the sub-light sources are further arranged at intervals along a second direction on the two-dimensional plane where the light source array is located; the second direction is perpendicular to the first direction;

[0017] The point light spots in the light spot array are also arranged at intervals along the line width direction of the line light spot.

[0018] In an exemplary embodiment of the present application, in the second direction, the intervals between adjacent sub-light sources are equal;

[0019] Alternatively, in the second direction, there are at least two types of intervals between adjacent sub-light sources.

[0020] In an exemplary embodiment of the present application, in the first direction, the spacing between adjacent sub-light sources is equal; in the second direction, the spacing between adjacent sub-light sources is equal; and the spacing between adjacent sub-light sources in the first direction is equal to the spacing between adjacent sub-light sources in the second direction.

[0021] In an exemplary embodiment of the present application, in the first direction, the spacing between adjacent sub-light sources is equal; in the second direction, the spacing between adjacent sub-light sources is equal; and the spacing between adjacent sub-light sources in the second direction is greater than the spacing between adjacent sub-light sources in the first direction.

[0022] In an exemplary embodiment of the present application, the spacing between at least one pair of adjacent sub-light sources in the second direction is greater than the maximum spacing between adjacent sub-light sources in the first direction, so that when all the sub-light sources are lit, the light beam output by the superlens is projected on the target plane to obtain at least two line spots arranged at intervals along the line width direction.

[0023] According to one aspect of an embodiment of the present application, a laser radar is disclosed, the laser radar comprising: an optical transmitting module as provided in any one of the above embodiments; an optical receiving module;

[0024] The optical receiving module is used to receive the light beam reflected by the surface of the target object from the line light spot projected by the optical transmitting module.

[0025] During the actual use of the optical emission module provided by the present application in projecting a line spot, the first distance maintained between the metalens and the light source array is different from the second distance for the metalens to perform the collimation function. Therefore, when designing the phase distribution of the metalens in the optical emission module provided by the present application, it is only necessary to design the corresponding collimation phase based on the focal length of the metalens, and then defocus the distance between the metalens and the light source array. Whether it is compared to position mapping the light intensity distribution to design the phase distribution of the metalens, or compared to running the phase recovery algorithm to perform phase recovery to design the phase distribution of the metalens, it is more convenient to design the collimation phase of the metalens based on the focal length of the metalens; therefore, the optical emission module provided by the present application can more conveniently design the phase distribution of the metalens, so that the light beam output by the metalens can be projected to obtain a line spot.

[0026] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by the practice of the present application.

[0027] It should be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and other objects, features and advantages of the present application will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings.

[0029] Figure 1 A schematic diagram of light beam modulation of the optical emission module provided by the present application is shown when the metalens and the light source array maintain a first distance.

[0030] Figure 2 A schematic diagram of light beam modulation of the optical emission module provided by the present application is shown when the super lens and the light source array maintain a second distance.

[0031] Figure 3 The figure shows a schematic diagram of the change of the point light spot during the process of defocusing the distance between the superlens and the light source array after the collimation phase of the superlens is designed.

[0032] Figure 4 A schematic diagram of a light source array, a light spot array, and a line light spot is shown when the intervals between adjacent sub-light sources are equal in a first direction in an embodiment of the present application.

[0033] Figure 5 A schematic diagram of a light source array, a light spot array, and a line light spot is shown in an embodiment of the present application when, in a first direction, there are at least two types of intervals between adjacent sub-light sources.

[0034] Figure 6 A schematic diagram of a light source array, a light spot array, and a line light spot is shown when, in an embodiment of the present application, the spacing between adjacent sub-light sources in the first direction is equal, the spacing between adjacent sub-light sources in the second direction is equal, and the spacing between adjacent sub-light sources in the first direction is equal to the spacing between adjacent sub-light sources in the second direction.

[0035] Figure 7 A schematic diagram of a light source array, a light spot array, and a line light spot is shown in an embodiment of the present application, when the spacing between adjacent sub-light sources in the first direction is equal, the spacing between adjacent sub-light sources in the second direction is equal, and the spacing between adjacent sub-light sources in the second direction is greater than the spacing between adjacent sub-light sources in the first direction.

[0036] Figure 8 A schematic diagram of a light source array, a light spot array and a line light spot is shown when the spacing between at least one pair of adjacent sub-light sources in the second direction is greater than the maximum spacing between adjacent sub-light sources in the first direction in an embodiment of the present application.

[0037] Fig. 9A schematic diagram of a light source array, a light spot array and a line light spot is shown when the spacing between at least one pair of adjacent sub-light sources in the second direction is greater than the maximum spacing between adjacent sub-light sources in the first direction in an embodiment of the present application.

[0038] Fig.10 The collimation phase included in the phase distribution of the metalens in one embodiment of the present application is shown.

[0039] Fig.11 The first replica phase included in the phase distribution of the metalens in one embodiment of the present application is shown.

[0040] Fig.12 The phase distribution of the metalens in one embodiment of the present application is shown.

[0041] Fig.13 A schematic diagram showing a line spot obtained by projecting the light beam output by the superlens at a working distance of 1 m when only the VCSEL with y=0 mm is lit in an embodiment of the present application.

[0042] Fig.14 Shows Fig.13 Schematic diagram of the one-dimensional light intensity distribution of the line spot along the x-axis direction.

[0043] Fig.15 A schematic diagram showing a line spot obtained by projecting the light beam output by the superlens at a working distance of 1 m when only the VCSEL with y=2.5 mm is lit in an embodiment of the present application.

[0044] Fig.16 Shows Fig.15 Schematic diagram of the one-dimensional light intensity distribution of the line spot along the x-axis direction.

[0045] Description of reference numerals:

[0046] 1-light source array; 11-sub-light source; 2-superlens; 21-substrate; 22-micro-nano structure; 3-target plane. DETAILED DESCRIPTION

[0047] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these example embodiments are provided so that the description of the present application will be more comprehensive and complete and the concepts of the example embodiments will be fully conveyed to those skilled in the art. The accompanying drawings are only schematic illustrations of the present application and are not necessarily drawn to scale. The same reference numerals in the figures represent the same or similar parts, and thus their repeated description will be omitted.

[0048] In addition, the described features, structures or characteristics may be combined in one or more example embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the example embodiments of the present application. However, those skilled in the art will appreciate that the technical solution of the present application may be practiced while omitting one or more of the specific details, or other methods, components, steps, etc. may be adopted. In other cases, known structures, methods, implementations or operations are not shown or described in detail to avoid obscuring the present application and making the various aspects of the present application obscure.

[0049] Some of the blocks shown in the accompanying drawings are functional entities that do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0050] The metalens modulates the light beam emitted by the light source through its phase distribution. In order to enable the metalens in the optical emission module to modulate the light beam emitted by the light source so that the output light beam can be projected to obtain a linear spot, the relevant technology proposes the following two methods to design the phase distribution of the metalens:

[0051] 1. Use geometric method to design the phase distribution of superlens.

[0052] Specifically, according to the law of conservation of energy, if the energy loss of the light beam during propagation is ignored, the total energy of the light beam received by the superlens is equal to the total energy of the light beam modulated and output by the superlens. The total energy of the light beam can be described by the light intensity distribution of the light beam.

[0053] Therefore, the intensity distribution of light received by the metalens is determined according to the light source, and the target intensity distribution of the target modulation output of the metalens is determined according to the design requirements. Then, based on the law of conservation of energy, each position on the intensity distribution of light received by the metalens is mapped one by one to each position on the target intensity distribution. Based on the position mapping relationship, the light beam exit angle at each position on the metalens can be determined. At the same time, the light beam incident angle at each position on the metalens can also be determined according to the light source. Therefore, by applying the generalized Snell's law, combined with the light beam incident angle and the light beam exit angle, the phase distribution of the metalens can be calculated.

[0054] The phase distribution obtained by the initial calculation usually cannot truly make the superlens modulate the output target light intensity distribution. Therefore, after the phase distribution of the superlens is obtained by the initial calculation, it is usually necessary to perform multiple iterative optimizations on the phase distribution of the superlens according to the same mapping logic to finally obtain a phase distribution that can make the superlens modulate the output target light intensity distribution.

[0055] 2. Use the phase recovery algorithm to design the phase distribution of the superlens.

[0056] Specifically, the phase recovery algorithm can be a GS (Gerchberg-Saxton) algorithm or a Yang-Gu algorithm. The target image is set according to the target light intensity distribution, and the target image is the target output of the phase recovery algorithm; the phase distribution of the metalens is randomly initialized to provide an initial input for the phase recovery algorithm. After the target output and the initial input are determined, the phase recovery algorithm can be run to perform phase recovery and perform multiple iterative optimizations; each iterative optimization will update the phase distribution of the metalens; after multiple iterative optimizations, a phase distribution that enables the metalens to modulate the output target light intensity distribution is finally obtained.

[0057] Whether it is to perform position mapping for light intensity distribution to design the phase distribution of the metalens, or to run a phase recovery algorithm to perform phase recovery to design the phase distribution of the metalens, the processing process is relatively complicated. Therefore, in order for the optical emission module provided by the related art to enable the light beam output by the metalens to project a line spot, it is necessary to design the phase distribution of the metalens in a relatively complex manner.

[0058] In order to overcome the above-mentioned defects of the related art, the present application provides an optical emission module. The optical emission module provided by the present application can more conveniently design the phase distribution of the super lens, so that the light beam output by the super lens can be projected to obtain a linear light spot.

[0059] Figure 1 A schematic diagram of light beam modulation of the optical emission module provided by the present application when the metalens and the light source array maintain a first distance is shown, Figure 2 A schematic diagram of light beam modulation of the optical emission module provided by the present application is shown when the super lens and the light source array maintain a second distance.

[0060] See also Figure 1 as well as Figure 2 The optical emission module provided in this application includes: a light source array 1; a super lens 2.

[0061] The light source array 1 includes at least two sub-light sources 11. The sub-light sources 11 are arranged along at least a first direction (in a two-dimensional plane) on which the light source array 1 is located. Figure 1 as well as Figure 2 In the embodiment, the first direction is parallel to the x-axis) and is arranged at intervals; that is, the light source array 1 can be a one-dimensional array or a two-dimensional array.

[0062] When the light source array 1 is a one-dimensional array, the sub-light sources 11 are arranged at intervals only along the first direction on the two-dimensional plane where the light source array 1 is located. When the light source array 1 is a two-dimensional array, the sub-light sources 11 are arranged at intervals along the first direction on the two-dimensional plane where the light source array 1 is located, and also along the second direction (in the two-dimensional plane where the light source array 1 is located) Figure 1 as well as Figure 2 Preferably, the first direction is perpendicular to the second direction.

[0063] The superlens 2 includes a substrate 21 and a micro-nano structure 22 disposed on the substrate 21, wherein the micro-nano structure 22 is a sub-wavelength structure. The superlens 2 mainly modulates the light beam through the micro-nano structure 22. Specifically, the micro-nano structure 22 at each position on the superlens 2 can provide a certain phase for the received light beam, and apply a certain phase delay to the light beam received at each position, so that a corresponding phase gradient is generated at each position on the superlens 2, thereby modulating the light beam received at each position.

[0064] In the embodiment of the present application, the superlens 2 is arranged on the light output side of the light source array 1, and the superlens 2 is used to receive the light beam emitted by the light source array 1, and then modulate and output the light beam emitted by the light source array 1.

[0065] See also Figure 1 In the embodiment of the present application, the first distance d1 is maintained between the metalens 2 and the light source array 1; when the first distance d1 is maintained, the light beam output by the metalens 2 is used to project a line spot on the target plane 3. The projection of the first direction on the target plane 3 is parallel to the line length direction of the line spot; Figure 1 as well as Figure 2 For example, the first direction in which the sub-light sources 11 are arranged at intervals is parallel to the x-axis, and the line length direction of the line light spot is also parallel to the x-axis.

[0066] In the embodiment of the present application, the phase distribution of the superlens 2 includes a collimated phase designed based on the focal length f of the superlens 2. However, in the actual use of the optical emission module, the first distance d1 maintained between the superlens 2 and the light source array 1 is not equal to the focal length f of the superlens 2.

[0067] In detail, in the design stage, the focal length f of the metalens 2 can be determined first, and then the collimation phase of the metalens 2 can be designed based on the focal length f. Figure 2 , if the focal length f is maintained between the superlens 2 and the light source array 1, the superlens 2 is used to collimate the light beam emitted by the light source array 1; the light beams emitted by each sub-light source 11 are modulated by the superlens 2 and emitted as parallel light or approximately parallel light, and then projected onto the target plane 3 to obtain corresponding point light spots; thus, the point light spots corresponding to all sub-light sources 11 are arranged at intervals on the target plane 3 to form a light spot array. Figure 2 Among them, the sub-light sources 11 are arranged at intervals at least parallel to the x-axis. Thus, the point light spots are arranged at intervals at least parallel to the x-axis.

[0068] After designing the collimation phase of the metalens 2 based on the focal length f of the metalens 2, defocusing is performed on the distance between the metalens 2 and the light source array 1; that is, taking the focal length f as the reference distance, increasing or decreasing the distance between the metalens 2 and the light source array 1.

[0069] It should be noted that if the collimation phase of the metalens 2 is to collimate the light beams emitted by the light source array 1 as expected, it is necessary to control the distance between the metalens 2 and the light source array 1 to be close enough to the focal length f of the metalens 2. Once the distance between the metalens 2 and the light source array 1 deviates significantly from the focal length f of the metalens 2, after the light beams emitted by each sub-light source 11 are modulated by the metalens 2, they will continue to propagate in a diffused manner, or continue to propagate in a manner of first converging and then diffusing; in this way, the area of the point light spots projected on the target plane 3 will increase.

[0070] Figure 3 Shows a schematic diagram of the change of the point light spots during the process of defocusing the distance between the metalens 2 and the light source array 1 after designing the collimation phase of the metalens 2. See Figure 2 and Figure 3 , the sub-light sources 11 are arranged at intervals at least parallel to the x-axis. When the distance between the metalens 2 and the light source array 1 is equal to the focal length f of the metalens 2, the absolute value of the defocus amount is 0, and the point light spots projected on the target plane 3 are arranged at intervals at least parallel to the x-axis. Among them, the defocus amount refers to the offset amount of the distance between the metalens 2 and the light source array 1 relative to the focal length f of the metalens 2; the positive and negative of the defocus amount represent the offset direction. Optionally, when the defocus amount is positive, the distance between the metalens 2 and the light source array 1 is greater than the focal length f of the metalens 2; when the defocus amount is negative, the distance between the metalens 2 and the light source array 1 is less than the focal length f of the metalens 2.

[0071] In the case where the defocus amounts are both positive or both negative, as the absolute value of the defocus amount gradually increases (D1 < D2 < D3), the area of each point light spot becomes larger and larger, and at the same time, the gap between adjacent point light spots on the x-axis becomes smaller and smaller until the adjacent point light spots on the x-axis just touch each other and then overlap (in Figure 3 , when the absolute value of the defocus amount is D2, the adjacent point light spots on the x-axis just touch each other), thereby forming a line light spot with the line length direction parallel to the x-axis.

[0072] It can be seen that by first designing the corresponding collimation phase based on the focal length f of the superlens 2, and then defocusing the distance between the superlens 2 and the light source array 1, the light beam output by the superlens 2 can be projected onto the target plane 3 to obtain a line spot.

[0073] In the embodiment of the present application, the distance matching the focal length f of the metalens 2 is recorded as the second distance d2. Within the allowable tolerance range, the second distance d2 is equivalent to the focal length f of the metalens 2; that is, the second distance d2 can vary to a certain extent with the focal length f of the metalens 2 as the center. Therefore, there is at least one second distance d2 different from the first distance d1. If the second distance d2 is maintained between the light source array 1 and the metalens 2, the metalens 2 is used to collimate the light beam emitted by the light source array 1, so that the light beam output by the metalens 2 is used to project on the target plane 3 to obtain a light spot array, and the point light spots in the light spot array are arranged at least at intervals along the line length direction.

[0074] However, in the embodiment of the present application, the actual distance between the light source array 1 and the metalens 2 is the first distance d1, not the second distance d2. When the first distance d1 is maintained, the light beam output by the metalens 2 is used to project a line spot on the target plane. Since the first distance d1 is obtained by defocusing based on the focal length f of the metalens 2, the first distance d1 is different from the second distance d2.

[0075] In summary, it can be seen that, due to the optical emission module provided by the present application, when designing the phase distribution of the superlens 2, it is only necessary to design the corresponding collimation phase based on the focal length f of the superlens 2, and then defocus the distance between the superlens 2 and the light source array 1; and whether it is compared with position mapping the light intensity distribution to design the phase distribution of the superlens 2, or compared with running the phase recovery algorithm to perform phase recovery to design the phase distribution of the superlens 2, it is more convenient to design the collimation phase of the superlens 2 based on the focal length f of the superlens 2; therefore, the optical emission module provided by the present application can more conveniently design the phase distribution of the superlens 2, so that the light beam output by the superlens 2 can be projected to obtain a linear spot.

[0076] In one embodiment, when designing the collimation phase of the metalens 2 based on the focal length f, the collimation phase of the metalens 2 may be designed using a hyperbolic phase or a multi-order polynomial phase.

[0077] Considering that when a hyperbolic phase is used to design the collimation phase of the metalens 2, in order to make the light beam emitted by the sub-light source 11 have an excellent collimation effect after collimation, the sub-light source 11 needs to be approximated as a point light source, and the sub-light source 11 needs to be located on the optical axis of the light beam emitted by the light source array 1.

[0078] However, since the sub-light sources 11 actually have a certain size, when the distance between the metalens 2 and the light source array 1 is not far enough, the sub-light sources 11 are difficult to be approximated as point light sources; moreover, in the light source array 1, there are always multiple sub-light sources 11 that are not on the optical axis of the light beam emitted by the light source array 1. Therefore, when the collimation phase of the metalens 2 is designed using a hyperbolic phase, it is difficult to ensure that the light beam emitted by each sub-light source 11 has an excellent collimation effect after collimation.

[0079] Therefore, it is preferred to use a multi-order polynomial phase to design the collimation phase of the superlens 2.

[0080] Optionally, the collimation phase of the metalens 2 obtained by multi-order polynomial phase design can be expressed as:

[0081]

[0082] Wherein, r is the radial distance of each position on the metalens 2 relative to the center of the effective area of ​​the metalens 2; is the collimation phase of the super lens 2; i is the order; a i are coefficients of each order.

[0083] In one embodiment, in the first direction, the intervals between adjacent sub-light sources 11 are equal.

[0084] In this case, if the second distance d2 is maintained between the metalens 2 and the light source array 1, the spacing between adjacent point light spots in the line length direction in the light spot array projected on the target plane 3 is also equal; at the same time, the gaps between adjacent point light spots in the line length direction are also equal. In this way, in the process of further defocusing the metalens 2 and the light source array 1, all adjacent point light spots in the line length direction will synchronously contact each other and then synchronously overlap each other.

[0085] When all adjacent point light spots in the line length direction overlap synchronously, the overlapping area of ​​each pair of adjacent point light spots in the line length direction is the same. Therefore, when the first distance d1 is maintained between the metalens 2 and the light source array 1, the light intensity distribution of the line light spot projected on the target plane 3 along the line length direction can have a high uniformity.

[0086] Figure 4 A schematic diagram of the light source array 1 , the light spot array and the line light spot is shown when the intervals between adjacent sub-light sources 11 are equal in the first direction in an embodiment of the present application.

[0087] See also Figure 4 In one embodiment, the first direction on the two-dimensional plane where the light source array 1 is located is parallel to the x-axis, and the line length direction of the line spot is also parallel to the x-axis. Figure 4In the figure, four sub-light sources 11 arranged at intervals along the x-axis direction are exemplarily used to represent the light source array 1, and the intervals between adjacent sub-light sources 11 in the light source array 1 are equal, i.e., x1.

[0088] Therefore, if the second distance d2 is maintained between the metalens 2 and the light source array 1, the light spot array obtained by projecting the light beam output by the metalens 2 onto the target plane 3 includes four point light spots arranged at intervals along the x-axis direction, and the spacing between adjacent point light spots in the light spot array is also equal.

[0089] Therefore, if the distance between the super lens 2 and the light source array 1 is further defocused, as the absolute value of the defocus amount continues to increase, the area of ​​each point light spot will continue to expand synchronously until the adjacent point light spots just touch each other. When one pair of adjacent point light spots just touch each other, it means that all three pairs of adjacent point light spots also just touch each other, so all the point light spots together form a line light spot.

[0090] If the absolute value of the defocus amount is further increased, all three pairs of adjacent point spots will overlap synchronously, so the overlapping area of ​​each pair of adjacent point spots is the same. Therefore, the light intensity distribution of the projected line spot along the line length direction can have a higher uniformity.

[0091] In one embodiment, in the first direction, there are at least two types of intervals between adjacent sub-light sources 11 .

[0092] In this case, if the second distance d2 is maintained between the metalens 2 and the light source array 1, then in the light spot array projected on the target plane 3, there are at least two kinds of spacings between adjacent point light spots in the line length direction; at the same time, there are at least two kinds of gaps between adjacent point light spots in the line length direction. In this way, in the process of further defocusing the metalens 2 and the light source array 1, there are at least two pairs of adjacent point light spots in the line length direction that will asynchronously contact each other and asynchronously overlap each other.

[0093] In this embodiment, by reasonably controlling the defocus amount, when the first distance d1 is maintained between the metalens 2 and the light source array 1, some adjacent point light spots in the line length direction contact and overlap with each other to form line light spots, while gaps are still left between other adjacent point light spots; in this way, multiple line light spots arranged at intervals along the line length direction can be obtained at the same time.

[0094] Figure 5 It shows a schematic diagram of the light source array 1, the light spot array and the line light spot when, in an embodiment of the present application, there are at least two types of intervals between adjacent sub-light sources 11 in the first direction.

[0095] See also Figure 5In one embodiment, the first direction on the two-dimensional plane where the light source array 1 is located is parallel to the x-axis, and the line length direction of the line spot is also parallel to the x-axis. Figure 5 In the figure, four sub-light sources 11 arranged at intervals along the x direction represent the light source array 1 by way of example, and adjacent sub-light sources in the light source array 1 have two spacings: from left to right, the spacing between the first sub-light source 11 and the second sub-light source 11 is x2, the spacing between the second sub-light source 11 and the third sub-light source 11 is x1, and the spacing between the third sub-light source and the fourth sub-light source 11 is x2; x1 is greater than x2.

[0096] Therefore, if the second distance d2 is maintained between the metalens 2 and the light source array 1, the light spot array obtained by projecting the light beam output by the metalens 2 on the target plane 3 includes 4 point light spots arranged at intervals along the x-axis direction, and adjacent point light spots in the light spot array also have two spacings - from left to right, the spacing between the first point light spot and the second point light spot is equal to the spacing between the third point light spot and the fourth point light spot, and is smaller than the spacing between the second point light spot and the third point light spot.

[0097] Therefore, if the distance between the metalens 2 and the light source array 1 is further defocused, as the absolute value of the defocus amount continues to increase, the area of ​​each point light spot will continue to expand synchronously until the first point light spot and the second point light spot are just in contact with each other, and the third point light spot and the fourth point light spot are just in contact with each other, and at the same time, there is still a gap between the second point light spot and the third point light spot. Therefore, all the point light spots form two line light spots arranged at intervals along the length direction of the line.

[0098] If the absolute value of the defocus amount is further increased, the first spot and the second spot, as well as the third spot and the fourth spot, will overlap synchronously; within a certain range, there can still be a certain gap between the second spot and the third spot. Therefore, all the spot can still form two line spots spaced apart along the length of the line.

[0099] In one embodiment, the super lens 2 is also used to replicate the line light spot along the line length direction; thus, the coverage of the line light spot in the line length direction can be expanded.

[0100] In this embodiment, the designed phase distribution of the superlens 2 includes not only a collimation phase for collimating the light beam emitted by the light source array 1 at the second distance d2, but also a first replication phase for replicating the line spot along the line length direction.

[0101] The number of sub-light sources 11 arranged at intervals in the first direction is a; a is an integer greater than 1. When the phase distribution of the superlens 2 includes only the collimated phase - if the second distance d2 is maintained between the superlens 2 and the light source array 1, then in the light spot array obtained by projecting the light beam output by the superlens 2, a point light spots will be arranged at intervals in the line length direction; the first distance d1 is maintained between the superlens 2 and the light source array 1, so these a point light spots merge to form a line light spot with a length of L.

[0102] When the phase distribution of the metalens 2 includes the collimated phase and the first replica phase - if the second distance d2 is maintained between the metalens 2 and the light source array 1, then in the light spot array obtained by projecting the light beam output by the metalens 2, M*a point light spots (M is an integer greater than 1) will be arranged at intervals in the line length direction; the first distance d1 is maintained between the metalens 2 and the light source array 1, so these M*a point light spots constitute M line light spots with a length of L.

[0103] According to application requirements, these M line light spots with a length of L can be arranged at intervals along the line length direction, or can be closely spliced ​​together along the line length direction to form a line light spot with a length of M*L.

[0104] In one embodiment, the super lens 2 is also used to replicate the line light spot along the line width direction; thus, the coverage of the line light spot in the line width direction can be expanded.

[0105] In this embodiment, the designed phase distribution of the superlens 2 includes not only a collimation phase for collimating the light beam emitted by the light source array 1 at the second distance d2, but also a second replication phase for replicating the line spot along the line width direction.

[0106] The number of sub-light sources 11 arranged in the second direction is denoted as b; b is an integer greater than 0, that is, only one sub-light source 11 may be arranged in the second direction.

[0107] When the phase distribution of the metalens 2 includes only the collimated phase - if the second distance d2 is maintained between the metalens 2 and the light source array 1, then in the light spot array obtained by projecting the light beam output by the metalens 2, there will be b point light spots arranged in the line width direction; the first distance d1 is maintained between the metalens 2 and the light source array 1, so these b point light spots correspond to b line light spots respectively.

[0108] When the phase distribution of the metalens 2 includes the collimated phase and the second replica phase - if the second distance d2 is maintained between the metalens 2 and the light source array 1, then in the light spot array obtained by projecting the light beam output by the metalens 2, N*b point light spots (N is an integer greater than 1) will be arranged at intervals in the line width direction; the first distance d1 is maintained between the metalens 2 and the light source array 1, so these N*b point light spots correspond to N*b line light spots.

[0109] According to application requirements, these N*b line spots can be arranged at intervals along the line width direction, or partially spliced ​​together and partially arranged at intervals along the line width direction, thereby forming K line spots, where K is an integer greater than 1 and K is less than N.

[0110] In one embodiment, the sub-light sources 11 are arranged at intervals along the first direction on the two-dimensional plane where the light source array 1 is located, and are also arranged at intervals along the second direction on the two-dimensional plane where the light source array 1 is located. The second direction is perpendicular to the first direction. Since the projection of the first direction on the target plane 3 is parallel to the line length direction of the line spot, and the line length direction of the line spot is perpendicular to the line width direction, the projection of the second direction on the target plane 3 is parallel to the line width direction of the line spot.

[0111] Therefore, in this embodiment, if the super lens 2 maintains a second distance d2 with the light source array 1, then in the light spot array obtained by projecting the light beam output by the super lens 2, the point light spots are arranged at intervals not only along the line length direction, but also along the line width direction.

[0112] In one embodiment, the sub-light sources 11 are arranged at intervals along the first direction and also arranged at intervals along the second direction. In addition, in the second direction, the intervals between adjacent sub-light sources 11 are equal.

[0113] In this case, if the second distance d2 is maintained between the metalens 2 and the light source array 1, then in the light spot array projected on the target plane 3, the spacing between adjacent point light spots in the line width direction is also equal; at the same time, the gaps between adjacent point light spots in the line width direction are also equal.

[0114] In this embodiment, by reasonably controlling the defocus amount, the spacing between adjacent sub-light sources 11 in the first direction, and the spacing between adjacent sub-light sources 11 in the second direction, it is possible to make it possible for adjacent point light spots in the line length direction to contact and overlap with each other when the first distance d1 is maintained between the superlens 2 and the light source array 1, while all adjacent point light spots in the line width direction do not contact or overlap with each other; in this way, a plurality of line light spots arranged at equal intervals along the line width direction can be obtained at the same time, and the line width of each line light spot is consistent.

[0115] In one embodiment, the sub-light sources 11 are arranged at intervals along the first direction and also arranged at intervals along the second direction. In addition, in the second direction, there are at least two types of intervals between adjacent sub-light sources 11 .

[0116] In this case, if the second distance d2 is maintained between the superlens 2 and the light source array 1, then in the light spot array projected on the target plane 3, there are at least two types of spacings between adjacent point light spots in the line width direction; at the same time, there are at least two types of gaps between adjacent point light spots in the line width direction.

[0117] In this embodiment, by reasonably controlling the defocus amount, the spacing between adjacent sub-light sources 11 in the first direction, and the spacing between adjacent sub-light sources 11 in the second direction, it is possible to make it possible for adjacent point light spots in the line length direction to contact and overlap with each other when the first distance d1 is maintained between the superlens 2 and the light source array 1, while all adjacent point light spots in the line width direction do not contact or overlap with each other; in this way, a plurality of line light spots arranged at unequal intervals along the line width direction can be obtained at the same time, and the line width of each line light spot is consistent.

[0118] Alternatively, by reasonably controlling the defocus amount, the spacing between adjacent sub-light sources 11 in the first direction, and the spacing between adjacent sub-light sources 11 in the second direction, it is also possible to ensure that when the first distance d1 is maintained between the superlens 2 and the light source array 1, adjacent point light spots in the line length direction contact and overlap with each other, and at the same time, some adjacent point light spots in the line width direction contact and overlap with each other, while another part of adjacent point light spots in the line width direction do not contact or overlap with each other; in this way, a plurality of line light spots with at least two line widths arranged at intervals along the line width direction can be obtained at the same time.

[0119] In one embodiment, the sub-light sources 11 are arranged at equal intervals along the first direction and at equal intervals along the second direction, and the interval between adjacent sub-light sources 11 in the first direction is equal to the interval between adjacent sub-light sources 11 in the second direction.

[0120] In this case, if all the sub-light sources 11 are lit, then in the process of further defocusing the superlens 2 and the light source array 1, when all adjacent point light spots in the line length direction synchronously just touch each other, all adjacent point light spots in the line width direction also synchronously just touch each other, and when all adjacent point light spots in the line length direction synchronously overlap each other, all adjacent point light spots in the line width direction also synchronously overlap each other; thus, all adjacent point light spots in the line width direction will be connected together, thereby significantly increasing the line width.

[0121] It should be noted that the application requirements for line light spots in the optical field usually require that the line width of the line light spot be as small as possible, so in general, it is necessary to avoid significantly increasing the line width. Therefore, in this embodiment, it is preferred to light up the sub-light sources 11 in a time-sharing manner to avoid all adjacent sub-light sources 11 in the second direction being lit up at the same time, thereby avoiding that all adjacent point light spots in the line width direction synchronously contact and overlap each other during the further defocusing process of the metalens 2 and the light source array 1.

[0122] Specifically, in this embodiment, only one sub-light source 11 may be lit at the same time along the line width direction, or unlit sub-light sources 11 may be spaced apart from each other along the line width direction.

[0123] Figure 6 A schematic diagram of the light source array 1, the light spot array and the line light spot is shown when, in an embodiment of the present application, the spacing between adjacent sub-light sources 11 in the first direction is equal, the spacing between adjacent sub-light sources 11 in the second direction is equal, and the spacing between adjacent sub-light sources 11 in the first direction is equal to the spacing between adjacent sub-light sources 11 in the second direction.

[0124] See also Figure 6 In one embodiment, the first direction on the two-dimensional plane where the light source array 1 is located is parallel to the x-axis, and the line length direction of the line spot is also parallel to the x-axis; the second direction on the two-dimensional plane where the light source array 1 is located is parallel to the y-axis, and the line width direction of the line spot is also parallel to the y-axis. Figure 6 In the figure, 12 sub-light sources 11 in a 4*3 rectangular array pattern are used to represent the light source array 1; in the first direction, the spacing between adjacent sub-light sources 11 is x1, and in the second direction, the spacing between adjacent sub-light sources 11 is y1, and x1 is equal to y1.

[0125] Therefore, if the second distance d2 is maintained between the metalens 2 and the light source array 1, the light spot array obtained by projecting the light beam output by the metalens 2 on the target plane 3 includes 12 point light spots in a 4*3 rectangular array pattern, and the spacing between adjacent point light spots in the line length direction is equal to the spacing between adjacent point light spots in the line width direction.

[0126] Therefore, if all the sub-light sources 11 are lit, and the distance between the super lens 2 and the light source array 1 is further defocused, the area of ​​each point light spot will be synchronously expanded as the absolute value of the defocus amount continues to increase - when the four adjacent point light spots in the line length direction just touch each other, the three adjacent point light spots in the line width direction also just touch each other, so all the 12 point light spots begin to connect together; further increase the absolute value of the defocus amount, the four adjacent point light spots in the line length direction overlap synchronously, and the three adjacent point light spots in the line width direction also overlap synchronously, so the connection between the 12 point light spots is higher. In this way, the line width is significantly increased.

[0127] In order from top to bottom, the 12 sub-light sources 11 are divided into 3 rows of sub-light sources 11, and the corresponding 12 point light spots are divided into 3 rows of point light spots.

[0128] In order to avoid a significant increase in line width, in this embodiment, only one row of sub-light sources 11 can be lit at the same time (for example, only the first row of sub-light sources 11 are lit at the same time; or, only the second row of sub-light sources 11 are lit at the same time; or, only the third row of sub-light sources 11 are lit at the same time). In this way, only one row of point light spots is projected at the same time, thereby forming a line light spot whose line width is not significantly increased.

[0129] In order to avoid a significant increase in line width, in this embodiment, only the first row of sub-light sources 11 and the third row of sub-light sources 11 can be lit at the same time, and the second row of sub-light sources 11 in the middle can be left unlit. In this way, only the first row of point light spots and the third row of point light spots are projected at the same time, thereby forming two alternately arranged line light spots whose line width is not significantly increased.

[0130] In one embodiment, the sub-light sources 11 are arranged at equal intervals along the first direction and at equal intervals along the second direction, and the interval between adjacent sub-light sources 11 in the second direction is greater than the interval between adjacent sub-light sources 11 in the first direction.

[0131] In this case, if all the sub-light sources 11 are lit, in the process of further defocusing the metalens 2 and the light source array 1, all the adjacent light spots in the line length direction will just touch each other before all the adjacent light spots in the line width direction. In other words, when all the adjacent light spots in the line length direction just touch each other, all the adjacent light spots in the line width direction are still arranged at intervals.

[0132] If the absolute value of the defocus amount is further increased, all adjacent point light spots in the line length direction begin to overlap with each other, and the overlapping range gradually increases; at the same time, the gaps between all adjacent point light spots in the line width direction become smaller and smaller, until they just touch each other and then overlap with each other. However, it can be understood that there is a certain size of defocus amount interval from the defocus amount that makes "all adjacent point light spots in the line length direction just touch each other" to the defocus amount that makes "all adjacent point light spots in the line width direction just touch each other". As long as the defocus amount is reasonably controlled within the defocus amount interval, when all the sub-light sources 11 are lit, multiple line light spots arranged at equal intervals along the line width direction can be obtained, and the line width of each line light spot is consistent and has not increased significantly.

[0133] Figure 7 A schematic diagram of the light source array 1, the light spot array and the line light spot is shown in an embodiment of the present application, when the spacing between adjacent sub-light sources 11 in the first direction is equal, the spacing between adjacent sub-light sources 11 in the second direction is equal, and the spacing between adjacent sub-light sources 11 in the second direction is greater than the spacing between adjacent sub-light sources 11 in the first direction.

[0134] See also Figure 7 In one embodiment, the first direction on the two-dimensional plane where the light source array 1 is located is parallel to the x-axis, and the line length direction of the line spot is also parallel to the x-axis; the second direction on the two-dimensional plane where the light source array 1 is located is parallel to the y-axis, and the line width direction of the line spot is also parallel to the y-axis. Figure 7 In the figure, 12 sub-light sources 11 in a 4*3 rectangular array pattern are used to represent the light source array 1; in the first direction, the spacing between adjacent sub-light sources 11 is x1, and in the second direction, the spacing between adjacent sub-light sources 11 is y2, and y2 is greater than x1.

[0135] Therefore, if the second distance d2 is maintained between the metalens 2 and the light source array 1, the light spot array obtained by projecting the light beam output by the metalens 2 on the target plane 3 includes 12 point light spots in a 4*3 rectangular array pattern, and the spacing between adjacent point light spots in the line width direction is greater than the spacing between adjacent point light spots in the line length direction.

[0136] Therefore, if all the sub-light sources 11 are lit, and the distance between the superlens 2 and the light source array 1 is further defocused, the area of ​​each point light spot will continue to expand synchronously as the absolute value of the defocus amount continues to increase - when the four adjacent point light spots in the line length direction just touch each other, the three adjacent point light spots in the line width direction are still arranged at intervals; if the absolute value of the defocus amount is further increased, the four adjacent point light spots in the line length direction begin to overlap with each other, and at the same time, the three adjacent point light spots in the line width direction can still be arranged at intervals within a certain defocus amount range.

[0137] It can be seen that in this embodiment, as long as the defocus amount is reasonably controlled, when all the sub-light sources 11 are lit, three line light spots arranged at equal intervals along the line width direction can be obtained, and the line width of each line light spot is consistent and does not increase significantly.

[0138] In one embodiment, the sub-light sources 11 are arranged at intervals along the first direction (they can be arranged at equal intervals along the first direction, or they can be arranged at unequal intervals along the first direction), and are also arranged at intervals along the second direction (they can be arranged at equal intervals along the second direction, or they can be arranged at unequal intervals along the second direction). In addition, the spacing between at least one pair of adjacent sub-light sources 11 in the second direction is greater than the maximum spacing between adjacent sub-light sources 11 in the first direction, so that when all the sub-light sources 11 are lit, the light beam output by the metalens 2 is projected on the target plane 3 to obtain at least two line spots arranged at intervals along the line width direction.

[0139] In this case, if all the sub-light sources 11 are lit, during the further defocusing process of the superlens 2 and the light source array 1, when the pair of adjacent point light spots that are farthest apart in the line length direction just touch each other, the other pairs of adjacent point light spots in the line length direction either overlap with each other or just touch each other; at the same time, at least one pair of adjacent point light spots in the line width direction is still arranged at intervals (as for the other pairs of adjacent point light spots in the line width direction, they can be arranged at intervals, can just touch each other, or can overlap with each other).

[0140] In this way, by properly controlling the defocus amount, when all the sub-light sources 11 are lit, at least two line light spots spaced apart along the line width direction can be obtained.

[0141] Figure 8 A schematic diagram of the light source array 1, the light spot array and the line light spot is shown when the spacing between at least one pair of adjacent sub-light sources 11 in the second direction is greater than the maximum spacing between adjacent sub-light sources 11 in the first direction in an embodiment of the present application.

[0142] See also Figure 8 In one embodiment, the first direction on the two-dimensional plane where the light source array 1 is located is parallel to the x-axis, and the line length direction of the line spot is also parallel to the x-axis; the second direction on the two-dimensional plane where the light source array 1 is located is parallel to the y-axis, and the line width direction of the line spot is also parallel to the y-axis.

[0143] Figure 8 In the figure, 12 sub-light sources 11 in a 4*3 rectangular array pattern are used as an example to represent the light source array 1. In the first direction, the spacing between adjacent sub-light sources 11 is x1; in the second direction, in order from top to bottom, the spacing between the first pair of adjacent sub-light sources 11 (i.e., the first row of sub-light sources 11 and the second row of sub-light sources 11) is y1, and the spacing between the second pair of adjacent sub-light sources 11 (i.e., the second row of sub-light sources 11 and the third row of sub-light sources 11) is y2; y1 is equal to x1, and y2 is greater than x1.

[0144] Therefore, if the second distance d2 is maintained between the metalens 2 and the light source array 1, the light spot array obtained by projecting the light beam output by the metalens 2 on the target plane 3 includes 12 point light spots in a 4*3 rectangular array pattern; and, in order from top to bottom, the spacing between the first pair of adjacent point light spots in the line width direction (i.e., the first row of point light spots and the second row of point light spots) is equal to the spacing between the adjacent point light spots in the line length direction, and the spacing between the second pair of adjacent point light spots in the line width direction (i.e., the second row of point light spots and the third row of point light spots) is greater than the spacing between the adjacent point light spots in the line length direction.

[0145] Therefore, if all the sub-light sources 11 are lit, and the distance between the superlens 2 and the light source array 1 is further defocused, then as the absolute value of the defocus amount continues to increase, the area of ​​each point light spot will continue to expand synchronously - when the four adjacent point light spots in the line length direction just touch each other, the first pair of adjacent point light spots in the line width direction also just touch each other, and the second pair of adjacent point light spots in the line width direction are still arranged at intervals; further increase the absolute value of the defocus amount, the four adjacent point light spots in the line length direction begin to overlap with each other, the first pair of adjacent point light spots in the line width direction also begin to overlap with each other, and at the same time, the second pair of adjacent point light spots in the line width direction can still maintain an interval arrangement within a certain defocus amount range.

[0146] It can be seen that in this embodiment, as long as the defocus amount is reasonably controlled, when all the sub-light sources 11 are lit, two line light spots arranged at intervals along the line width direction can be obtained - the line light spot located above is composed of the first row of point light spots and the second row of point light spots, and the line light spot located below is composed of the third row of point light spots, so the line width of the line light spot located above is approximately twice the line width of the line light spot located below.

[0147] Fig. 9 A schematic diagram of the light source array 1, the light spot array and the line light spot is shown when the spacing between at least one pair of adjacent sub-light sources 11 in the second direction is greater than the maximum spacing between adjacent sub-light sources 11 in the first direction in an embodiment of the present application.

[0148] See also Fig. 9 In one embodiment, the first direction on the two-dimensional plane where the light source array 1 is located is parallel to the x-axis, and the line length direction of the line spot is also parallel to the x-axis; the second direction on the two-dimensional plane where the light source array 1 is located is parallel to the y-axis, and the line width direction of the line spot is also parallel to the y-axis.

[0149] Fig. 9 In the figure, 12 sub-light sources 11 in a 4*3 rectangular array pattern are used as an example to represent the light source array 1. In the first direction, the spacing between adjacent sub-light sources 11 is x1; in the second direction, in order from top to bottom, the spacing between the first pair of adjacent sub-light sources 11 (i.e., the first row of sub-light sources 11 and the second row of sub-light sources 11) is y2, and the spacing between the second pair of adjacent sub-light sources 11 (i.e., the second row of sub-light sources 11 and the third row of sub-light sources 11) is y3; y2 is greater than x1, and y3 is greater than y2.

[0150] Therefore, if the second distance d2 is maintained between the metalens 2 and the light source array 1, the light spot array obtained by projecting the light beam output by the metalens 2 on the target plane 3 includes 12 point light spots in a 4*3 rectangular array pattern; and, in order from top to bottom, the spacing between the first pair of adjacent point light spots in the line width direction (i.e., the first row of point light spots and the second row of point light spots) is greater than the spacing between the adjacent point light spots in the line length direction, and the spacing between the second pair of adjacent point light spots in the line width direction (i.e., the second row of point light spots and the third row of point light spots) is greater than the spacing between the first pair of adjacent point light spots in the line width direction.

[0151] Therefore, if all the sub-light sources 11 are lit, and the distance between the superlens 2 and the light source array 1 is further defocused, as the absolute value of the defocus amount continues to increase, the area of ​​each point light spot will continue to expand synchronously - when the four adjacent point light spots in the line length direction just touch each other, the first pair of adjacent point light spots in the line width direction and the second pair of adjacent point light spots are still arranged at intervals, and the gap between the second pair of adjacent point light spots in the line width direction is larger than the gap between the first pair of adjacent point light spots in the line width direction; further increase the absolute value of the defocus amount, the four adjacent point light spots in the line length direction begin to overlap with each other, and at the same time, the first pair of adjacent point light spots in the line width direction and the second pair of adjacent point light spots can be kept at intervals within a certain defocus range; continue to further increase the absolute value of the defocus amount, the overlap between the four adjacent point light spots in the line length direction increases, and the first pair of adjacent point light spots in the line width direction can begin to touch and overlap with each other, and at the same time, the second pair of adjacent point light spots in the line width direction can continue to be kept at intervals within a certain defocus range.

[0152] It can be seen that in this embodiment, as long as the defocus amount is reasonably controlled, when all the sub-light sources 11 are lit, three line light spots arranged at intervals along the line width direction can be obtained - the line light spot located at the top is composed of the first row of point light spots, the line light spot located in the middle is composed of the second row of point light spots, and the line light spot located at the bottom is composed of the third row of point light spots, and the line widths of these three line light spots are consistent; two line light spots arranged at intervals along the line width direction can also be obtained - the line light spot located at the top is composed of the first row of point light spots and the second row of point light spots, and the line light spot located at the bottom is composed of the third row of point light spots, so the line width of the line light spot located at the top is approximately twice the line width of the line light spot located at the bottom.

[0153] The present application also provides a laser radar. The laser radar provided by the present application includes: an optical transmitting module provided by any of the above embodiments; and an optical receiving module.

[0154] The light beam emitted by the optical emission module is used to project onto the surface of the target object to obtain a line light spot on the surface of the target object. The optical receiving module is used to receive the light beam reflected by the line light spot from the surface of the target object.

[0155] If the surface of the target object has certain ups and downs, the light beam reflected by the surface of the target object will contain the depth information of the surface of the target object. Therefore, the laser radar can perform three-dimensional sensing of the target object based on the light beam reflected by the surface of the target object received by the optical receiving module.

[0156] In one embodiment, in the optical emission module of the laser radar, a two-dimensional array of light source arrays 1 is preferably used. In this way, the sub-light sources 11 in the light source array 1 can be lit in time-sharing mode to achieve solid-state scanning of the line light spot; that is, the line light spot can be projected at different positions to achieve scanning without the help of mechanical moving parts.

[0157] In one embodiment, in the optical emission module of the laser radar, the light source array 1 is composed of 61*101 VCSELs arranged in a rectangular array. Specifically, 61 VCSELs are arranged at equal intervals along the x-axis direction (the line length direction is parallel to the x-axis), and the size of the light source array 1 in the x-axis direction is 2mm; 101 VCSELs are arranged at equal intervals along the y-axis direction (the line width direction is parallel to the y-axis), and the size of the light source array 1 in the y-axis direction is 5mm. The central wavelength of the light beam emitted by each VCSEL is 940nm, and the divergence angle of the light beam emitted by each VCSEL is 24°.

[0158] In this embodiment, the phase distribution of the metalens 2 includes a collimation phase and a first replication phase. The focal length when the collimation phase is designed is 28.575 mm; the first replication phase is used to replicate one line spot into three line spots along the line length direction, and the three replicated line spots are closely spliced ​​along the line length direction into one line spot with a length twice as long. Specifically, Fig.10 shows the collimation phase included in the phase distribution of the superlens 2 in this embodiment, Fig.11 Graph 1 shows the first replica phase included in the phase distribution of the superlens 2 in this embodiment. Fig.12 The phase distribution of the superlens 2 in this embodiment is shown.

[0159] For the 101 VCSELs arranged along the y-axis direction, the y-coordinate of the VCSEL located at the center is marked as "y=0 mm", and the y-coordinates of the two VCSELs located at the edge are "y=2.5 mm" and "y=-2.5 mm" respectively.

[0160] Fig.13The figure shows a schematic diagram of a line spot obtained by projecting the light beam output by the superlens 2 at a working distance of 1 m when only the VCSEL with y=0 mm is lit in this embodiment. Fig.14 Shows Fig.13 Schematic diagram of the one-dimensional light intensity distribution of the line spot along the x-axis direction. Fig.15 The figure shows a schematic diagram of a line spot obtained by projecting the light beam output by the superlens 2 at a working distance of 1 m when only the VCSEL with y=2.5 mm is lit in this embodiment. Fig.16 Shows Fig.15 Schematic diagram of the one-dimensional light intensity distribution of the line spot along the x-axis direction.

[0161] exist Fig.13 as well as Fig.15 In the figure, the horizontal axis represents the illumination coverage angle in the x-axis direction, in degrees, and the vertical axis represents the illumination coverage angle in the y-axis direction, in degrees. Specifically, the line between a certain position in the line spot and the center of the effective area of ​​the metalens 2 is determined, and then the angle of the line relative to the optical axis of the light beam output by the metalens 2 in the x-axis direction is determined, that is, the illumination coverage angle in the x-axis direction corresponding to the position is obtained; similarly, the line between a certain position in the line spot and the center of the effective area of ​​the metalens 2 is determined, and then the angle of the line relative to the optical axis of the light beam output by the metalens 2 in the y-axis direction is determined, that is, the illumination coverage angle in the y-axis direction corresponding to the position is obtained.

[0162] See also Figures 13 to 16 In this embodiment, by lighting up the VCSELs at different y coordinates, the light beam output by the super lens 2 can be projected at different positions to obtain a line light spot with uniform light intensity distribution. In this way, by lighting up the VCSELs at different y coordinates in a time-sharing manner, the laser radar in this embodiment can achieve solid-state scanning of the line light spot.

[0163] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the appended claims.

Claims

1. An optical transmission module, characterized in that: The optical emission module includes: a light source array; a super lens; The light source array comprises at least two sub-light sources, and the sub-light sources are arranged at intervals along at least a first direction on the two-dimensional plane where the light source array is located; The metalens is arranged at the light output side of the light source array, so as to modulate and output the light beam emitted by the light source array; a first distance is maintained between the metalens and the light source array, so that the light beam output by the metalens is used to project a line light spot on a target plane; the projection of the first direction on the target plane is parallel to the line length direction of the line light spot; Among them, there is at least one second distance different from the first distance. If the second distance is maintained between the metalens and the light source array, the metalens is used to collimate the light beam emitted by the light source array, so that the light beam output by the metalens is used to project a light spot array on the target plane; the point light spots in the light spot array are arranged at intervals at least along the line length direction.

2. The optical emission module according to claim 1, characterized in that: In the first direction, the intervals between adjacent sub-light sources are equal; Alternatively, in the first direction, there are at least two types of intervals between adjacent sub-light sources.

3. The optical emission module according to claim 1, characterized in that: The super lens is also used to replicate the line spot along the line length direction; If the second distance is maintained between the superlens and the light source array, the number of the light spots arranged at intervals along the line length direction in the light spot array is at least twice the number of the sub-light sources arranged at intervals along the first direction.

4. The optical emission module according to claim 1, characterized in that: The super lens is also used to replicate the line spot along the line width direction; If the second distance is maintained between the superlens and the light source array, the number of the light spots arranged at intervals along the line width direction in the light spot array is at least twice the number of the sub-light sources arranged along the second direction.

5. The optical emission module according to claim 1, characterized in that: The sub-light sources are also arranged at intervals along a second direction on the two-dimensional plane where the light source array is located; the second direction is perpendicular to the first direction; The point light spots in the light spot array are also arranged at intervals along the line width direction of the line light spot.

6. The optical emission module according to claim 5, characterized in that: In the second direction, the intervals between adjacent sub-light sources are equal; Alternatively, in the second direction, there are at least two types of intervals between adjacent sub-light sources.

7. The optical emission module according to claim 5, characterized in that: In the first direction, the spacings between adjacent sub-light sources are equal; in the second direction, the spacings between adjacent sub-light sources are equal; Furthermore, the spacing between adjacent sub-light sources in the first direction is equal to the spacing between adjacent sub-light sources in the second direction.

8. The optical emission module according to claim 5, characterized in that: In the first direction, the spacings between adjacent sub-light sources are equal; in the second direction, the spacings between adjacent sub-light sources are equal; Furthermore, a distance between adjacent sub-light sources in the second direction is greater than a distance between adjacent sub-light sources in the first direction.

9. The optical emission module according to claim 5, characterized in that: The spacing between at least one pair of adjacent sub-light sources in the second direction is greater than the maximum spacing between adjacent sub-light sources in the first direction, so that when all the sub-light sources are lit, the light beam output by the metalens is projected on the target plane to obtain at least two line spots arranged at intervals along the line width direction.

10. A laser radar, characterized in that: The laser radar comprises: an optical transmitting module as described in any one of claims 1 to 9; an optical receiving module; The optical receiving module is used to receive the light beam reflected by the surface of the target object from the line light spot projected by the optical transmitting module.

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