Superlens for three-dimensional sensing, transmitting device and laser radar

Abstract

The utility model provides a super lens for three-dimensional sensing, a transmitting device and a laser radar. The super lens comprises a substrate and a micro-nano structure arranged on the substrate, the super lens is used for shaping the received light beams into a plurality of linear light beams; each linear light beam is used for forming a corresponding linear light spot on a target plane, and all the linear light spots are jointly combined into a sine linear array light spot; wherein the light intensity distribution of the sine linear array light spots in the central cross section of the linear light spot in the line width direction is sine distribution. According to the device for three-dimensional sensing, sine linear array light spots can be projected through the single superlens, the size of the device for three-dimensional sensing is reduced, and the production cost of the device for three-dimensional sensing is effectively reduced.

Description

Technical Field

[0001] The present application relates to the field of optics, and particularly to a metalens for three-dimensional sensing, a transmitting device, and a lidar. Background Art

[0002] With the continuous progress and development of technology, the application of three-dimensional sensing technology is becoming more and more extensive. In the application scenarios of three-dimensional sensing technology, a lidar usually projects a one-dimensional line spot as an identification line through a transmitting device to scan an object or an environment. In some application scenarios, the lidar requires the transmitting device to generate a linear array spot including multiple one-dimensional line spots to scan an object or an environment, and the receiving device of the lidar then obtains the three-dimensional information of the object or the environment through the characteristics of the linear array spot.

[0003] In the prior art, a linear array spot with a sinusoidal light intensity distribution can be used for corresponding three-dimensional sensing. This is because the linear array spot with a sinusoidal light intensity distribution can improve the accuracy and performance of the device in practical applications due to the regularity and controllability of the light intensity distribution. However, in the prior art, a combination of multiple lenses and other optical elements (such as a digital micromirror device DMD, a mask) is used to achieve a linear array spot with a sinusoidal light intensity distribution, which will cause the device for three-dimensional sensing to have problems of large volume and high production cost. Summary of the Utility Model

[0004] An object of the present application is to provide a metalens for three-dimensional sensing, a transmitting device, and a lidar. The metalens for three-dimensional sensing provided by the present application can realize the function of emitting a sinusoidal linear array spot based on a single metalens, so that the device including it has a small volume and low production cost.

[0005] According to an aspect of an embodiment of the present application, a metalens for three-dimensional sensing, a transmitting device, and a lidar are disclosed, and the metalens includes: a substrate and a micro-nano structure disposed on the substrate;

[0006] The metalens is configured to shape the received light beam into at least two one-dimensional line beams; each one-dimensional line beam is configured to form a corresponding one-dimensional line spot on the target plane, and all the one-dimensional line spots are combined together to form a sinusoidal linear array spot; wherein, the light intensity distribution of the central cross-section of the sinusoidal linear array spot in the line width direction of the one-dimensional line spot is sinusoidal.

[0007] In an exemplary embodiment of the present application, in the sinusoidal linear array spot, any two adjacent one-dimensional line spots are a group of adjacent spots;

[0008] In the line width direction of the one-dimensional line spot, the central spacing between any two groups of adjacent spots is equal.

[0009] In an exemplary embodiment of the present application, the included angle between adjacent one-dimensional linear beams corresponding to adjacent light spots is greater than or equal to 0.05° and less than or equal to 45°.

[0010] In an exemplary embodiment of the present application, the sine line array light spot is symmetric about the central axis parallel to the line width direction of the one-dimensional linear light spot.

[0011] In an exemplary embodiment of the present application, the phase of the metalens includes a shaping phase and a replication phase; the shaping phase is at least used to compress the light beam received by the metalens in the line width direction of the one-dimensional linear light spot to obtain the one-dimensional linear beam; the replication phase is used to replicate the one-dimensional linear beam in the line width direction of the one-dimensional linear light spot to form an array of one-dimensional linear beams.

[0012] In an exemplary embodiment of the present application, the shaping phase is further used to expand the light beam received by the metalens in the line length direction of the one-dimensional linear light spot.

[0013] In an exemplary embodiment of the present application, the phase of the metalens further includes a collimation phase for collimating the light beam received by the metalens.

[0014] According to one aspect of the embodiments of the present application, a transmitting device is disclosed, the transmitting device includes: a light source; a metalens as described in any one of the above.

[0015] The metalens is disposed on the light emitting side of the light source.

[0016] In an exemplary embodiment of the present application, the light source is an EEL light source or a VCSEL light source.

[0017] According to one aspect of the embodiments of the present application, a lidar is disclosed, the lidar includes: a transmitting device as described in any one of the above; a receiving device.

[0018] The metalens, the transmitting device, and the lidar for three-dimensional sensing provided by the present application, the metalens includes: a substrate and micro-nano structures disposed on the substrate; the metalens is used to shape the light beam received by it into at least two one-dimensional linear beams; each one-dimensional linear beam is used to form a corresponding one-dimensional linear light spot on the target plane, and all the one-dimensional linear light spots are combined together to form a sine line array light spot; wherein, the light intensity distribution of the central cross-section of the sine line array light spot in the line width direction of the one-dimensional linear light spot is sinusoidal. The present application can project a sine line array light spot through a single metalens, reducing the volume of the device for three-dimensional sensing and effectively reducing the production cost of the device for three-dimensional sensing.

[0019] Other features and advantages of the present application will become apparent from the following detailed description, or will be learned in part from the practice of the present application.

[0020] It should be understood that the above general description and the following detailed description are only exemplary and do not limit the present application. Description of the Drawings

[0021] By referring to the accompanying drawings and describing its exemplary embodiments in detail, the above and other objects, features, and advantages of the present application will become more apparent.

[0022] Figure 1 The schematic structural diagram of the metalens provided by an embodiment of the present application is shown.

[0023] Figure 2 The schematic working diagram of the metalens provided by an embodiment of the present application is shown.

[0024] Figure 3 The schematic diagram of the sine line array light spot projected by the metalens provided by an embodiment of the present application is shown.

[0025] Figure 4 The schematic diagram of the sine line array light spot projected by the metalens provided by an embodiment of the present application is shown.

[0026] Figure 5 The overall view of the light intensity distribution of the sine line array light spot projected by the emission device provided by an embodiment of the present application is shown.

[0027] Figure 6 The partial view of the light intensity distribution of the sine line array light spot projected by the emission device provided by an embodiment of the present application is shown.

[0028] Figure 7 The sectional view of the central light intensity distribution along the line width direction of the sine line array light spot projected by the emission device provided by an embodiment of the present application is shown.

[0029] Reference Signs:

[0030] 1 - Metalens; 11 - Substrate; 12 - Micro-nano structure; 2 - Light source; 3 - Target plane; 4 - Light beam; 5 - One-dimensional line light beam; 6 - One-dimensional line light spot. Detailed Description of the Embodiments

[0031] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the examples set forth herein; rather, these example embodiments are provided so that this application will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. The drawings are merely schematic illustrations of the application and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and thus their repeated description will be omitted.

[0032] In addition, the described features, structures, or characteristics may be combined in any suitable manner in one or more example embodiments. In the following description, numerous specific details are provided to give a thorough understanding of the example embodiments of this application. However, those skilled in the art will realize that one or more of the specific details may be omitted in practicing the technical solutions of this application, or other methods, components, steps, etc. may be adopted. In other cases, well-known structures, methods, implementations, or operations are not shown or described in detail to avoid obscuring the various aspects of this application.

[0033] In the prior art, lidar often emits a one-dimensional line spot or a line array spot with multiple one-dimensional line spots as the identification line to scan an object or the environment, and the receiving end obtains the three-dimensional information of the object or the environment according to the characteristics of the spot, so as to realize the three-dimensional sensing of the object or the environment. The prior art can use a line array spot with a sinusoidal light intensity distribution for corresponding three-dimensional sensing. This is because the line array spot with a sinusoidal light intensity distribution can improve the accuracy and performance of the device in practical applications due to the regularity and controllability of the light intensity distribution. However, in the prior art, a combination of multiple lenses and other optical elements (such as a digital micromirror device DMD, a mask) is used to realize the projection of a line array spot with a sinusoidal light intensity distribution for three-dimensional sensing of an object or the environment, which will cause the device for three-dimensional sensing to have problems of large volume and high production cost.

[0034] In consideration of overcoming the above-mentioned defects existing in the related art, this application provides a metasurface lens for three-dimensional sensing, a transmitting device, and a lidar. Through the metasurface lens provided by this application, it is possible to emit a sinusoidal line array spot through a single metasurface lens, effectively reducing the volume of the system where the metasurface lens is located and correspondingly reducing the production cost.

[0035] This application provides a metasurface lens for three-dimensional sensing, as Figure 1 shown, Figure 1The structural schematic diagram of the metalens provided by an embodiment of the present application is shown. The metalens 1 includes: a substrate 11 and a micro-nano structure 12 disposed on the substrate 11, and the micro-nano structure 12 is a sub-wavelength structure. The metalens 1 mainly provides corresponding phases at various locations thereon by configuring parameters such as the material, cross-sectional size, height, and arrangement period of the micro-nano structure 12 at various locations thereon, applies different phase mutations to the received light beam, and further enables each position on the metalens 1 to have a certain phase gradient, so that the metalens 1 modulates the light beams received at different positions thereon.

[0036] Specifically, as Figure 2 shown, Figure 2 The working schematic diagram of the metalens provided by an embodiment of the present application is shown. The metalens 1 is used to receive the light beam 4 emitted by the light source 2, shape the light beam 4, and further obtain at least two one-dimensional line light beams 5, and project all the one-dimensional line light beams 5 onto the target plane 3; each one-dimensional line light beam 5 forms a corresponding one-dimensional line light spot 6 on the target plane 3; all the one-dimensional line light spots 6 are jointly combined into a sine line array light spot. Among them, the light intensity distribution of the sine line array light spot on the central cross-section in the line width direction of the one-dimensional line light spot 6 is sinusoidally distributed; the central cross-section of the sine line array light spot in the line width direction of the one-dimensional line light spot 6 refers to the cross-section that is perpendicular to the line width direction of the one-dimensional line light spot 6 and passes through the projection of the geometric center point of the effective area of the metalens 1 on the target plane. Figure 2 The dashed line in Figure 7 is the intersection line of the above-mentioned central cross-section and the target plane, and is also the central axis of the sine line array light spot parallel to the line width direction of the one-dimensional line light spot; the sinusoidal distribution means that the physical quantity is distributed in the law of a sine waveform, and the physical quantity at the origin is zero, as Figure 7 shown, Figure 7 The light intensity distribution cross-section diagram of an embodiment of the present application is shown.

[0037] It should be noted that the two-dimensional plane where the target plane 3 is located and the two-dimensional plane where the metalens 1 is located are parallel in space. See Figure 2 , Figure 2The coordinate axes of the two-dimensional plane where the metalens 1 is located and the coordinate axes of the two-dimensional plane where the target plane 3 is located are shown. The coordinate axes of the two-dimensional plane where the metalens 1 is located and the coordinate axes of the two-dimensional plane where the target plane 3 is located are parallel in space, that is, the x-axis of the two-dimensional plane where the metalens 1 is located is parallel to the x-axis of the two-dimensional plane where the target plane 3 is located; the same is true for the y-axis and the z-axis, which will not be elaborated here. Moreover, the perpendicular projection of the x-axis of the two-dimensional plane where the metalens 1 is located on the two-dimensional plane where the target plane 3 is located is perpendicular to the y-axis of the two-dimensional plane where the target plane 3 is located. Taking Figure 2 the shown three-dimensional coordinate system as a reference, the line width direction of all the one-line light spots 6 is the y-axis direction of the two-dimensional plane where the target plane 3 is located, and the line length direction is the x-axis direction of the two-dimensional plane where the target plane 3 is located. The projection of the geometric center point of the effective area of the metalens 1 on the target plane 3 is represented as the origin of the target plane, that is, at x = 0 and y = 0.

[0038] In the embodiment of the present application, each one-line light spot 6 in the sine line array light spot commonly has a central axis in the line width direction, as Figure 3 and Figure 4 shown. Figure 4 shows a schematic diagram of the sine line array light spot projected by the metalens provided in an embodiment of the present application. Figure 3 and Figure 4 The dashed lines in are the central axes of all the one-line light spots 6, and can also be understood as the central axes of the sine line array light spot parallel to the line width direction of the one-line light spot 6. Among them, the center spacing refers to the distance between two light spots along this central axis.

[0039] In one embodiment, any two adjacent one-line light spots 6 in the sine line array light spot are a group of adjacent light spots. Refer to Figure 3 , Figure 3 which shows a schematic diagram of the sine line array light spot projected by the metalens provided in an embodiment of the present application. Along the y-axis direction from top to bottom, the first one-line light spot 6 and the second one-line light spot 6 are a group of adjacent light spots; the second one-line light spot 6 and the third one-line light spot 6 are a group of adjacent light spots; the third one-line light spot 6 and the fourth one-line light spot 6 are also a group of adjacent light spots.

[0040] In the line width direction of the one-line light spot 6, the center spacing of any two groups of adjacent light spots is equal, that is, in this embodiment, the center spacing between any one light spot and its adjacent light spot is a fixed value and is equal. Refer to Figure 3 , Figure 3 The center spacings between the two light spots in each group of adjacent light spots in are d1, d2, and d3 respectively. In this embodiment, d1 = d2 = d3. As Figure 4 shown, Figure 4 shows a schematic diagram of the sine line array light spot projected by the metalens provided in an embodiment of the present application.Figure 4 It includes six light spots, Figure 4 In the sine linear array light spots in it, the center distances between two adjacent light spots that make up adjacent light spots are all equal, that is, d1 = d2 = d3 = d4 = d5.

[0041] It should be noted that the equal center distances between the center of each one-dimensional light spot 6 in the sine linear array light spots are actually realized by controlling the distance between each one-dimensional light beam 5 along the projection of the central axis of the sine linear array light spots on the superlens 1 when the superlens 1 replicates the one-dimensional light beam.

[0042] In an embodiment, the included angle between adjacent one-dimensional light beams corresponding to adjacent light spots is greater than or equal to 0.05° and less than or equal to 45°. The upper limit of the included angle value range ensures that the superlens 1 can project a sine linear array light spot while reducing the processing difficulty and production cost of the superlens 1; the lower limit ensures that the superlens 1 can project a sine linear array light spot with higher density, improving the three-dimensional sensing accuracy of the device where the superlens 1 is located. Preferably, the included angle is greater than or equal to 0.1° and less than or equal to 10°.

[0043] In an embodiment, the sine linear array light spot projected by the superlens 1 is a symmetric pattern, and the sine linear array light spot is symmetric about the central axis parallel to the line width direction of the one-dimensional light spot, that is, all the one-dimensional light spots 6 in the sine linear array light spot are symmetric about the central axis parallel to the line width direction. As Figure 3 and Figure 4 shown, Figure 3 and Figure 4 the sine linear array light spots shown are all symmetric about the central axis parallel to the line width direction, Figure 3 and Figure 4 the dotted lines in are the central axes parallel to the line width direction.

[0044] In another embodiment, the sine linear array light spot projected by the superlens 1 is also symmetric in the line width direction of the one-dimensional light spot. In this case, the sine linear array light spot is symmetric about the central axis parallel to the line length direction of the one-dimensional light spot.

[0045] In an embodiment, the phase of the superlens 1 includes a shaping phase and a replication phase. The shaping phase of the superlens 1 is at least used to compress the light beam 4 in the line width direction of the one-dimensional light spot 6 to obtain a one-dimensional light beam.

[0046] Specifically, refer to Figure 2, the line width direction of the one-dimensional line-shaped light spot 6 is the y-axis direction of the two-dimensional plane where the metalens 1 is located. That is to say, the metalens 1 compresses the light beam 4 in the y-axis direction of its two-dimensional plane, so that the one-dimensional line-shaped light beam 5 obtained by modulating the metalens 1 can form a one-dimensional line-shaped light spot 6 on the target plane 3 after propagating a certain distance. It can be understood that if the metalens 1 is only used to provide a shaping phase for the light beam 4, the one-dimensional line-shaped light beam 5 obtained only by shaping the phase of the metalens 1 is an ideal one-dimensional line-shaped light beam without distortion, and the one-dimensional line-shaped light spot 6 formed by projecting it on the target plane 3 is also an ideal one-dimensional line-shaped light spot without distortion.

[0047] Moreover, the replication phase of the metalens 1 is used to replicate the one-dimensional line-shaped light beam in the line width direction of the one-dimensional line-shaped light spot 6, so as to form a one-dimensional line-shaped light beam array, that is, a sine line array light spot.

[0048] Specifically, the replication phase is essentially a one-dimensional grating phase along the line width direction of the one-dimensional line-shaped light spot 6; after the metalens 1 modulates the light beam 4 into an ideal one-dimensional line-shaped light beam, the metalens 1 also replicates the ideal one-dimensional line-shaped light beam in the y-axis direction of its two-dimensional plane, so as to obtain a one-dimensional line-shaped light beam array. It should be noted that the description above mentions that the metalens 1 replicates the ideal one-dimensional line-shaped light beam after modulating the light beam 4 into an ideal one-dimensional line-shaped light beam, which is only for functional description. In actual situations, the shaping phase and the replication phase of the metalens 1 act on the light beam 4 simultaneously, without a sequence.

[0049] It should be noted that since the incident angles of the light beam 4 emitted by the light source 2 at each position on the metalens 1 are different, the two ends of the one-dimensional line-shaped light beam 5 replicated by the metalens 1 according to the ideal one-dimensional line-shaped light beam will be distorted in the x-axis direction, which is reflected in the bending of the one-dimensional line-shaped light spot 6 formed on the target plane 3. As Figure 3 and Figure 4 shown, Figure 3 and Figure 4 all the one-dimensional line-shaped light spots at both ends in the x-axis direction are bent differently, that is, the formed light spots are not in the shape of "one", so they are also called distorted one-dimensional line-shaped light spots. In this case, based on the superposition property of the phase of the metalens 1, the present application can project a sine line array light spot only through one metalens, thereby reducing the volume of the device for three-dimensional sensing and effectively reducing the cost of the device for three-dimensional sensing.

[0050] Moreover, since the objective in this application is to generate a sine linear array light spot, when the replication phase of the metalens 1 replicates the ideal one-dimensional linear light beam, it does not retain the directly emerging ideal one-dimensional linear light beam. Instead, it directly replicates the ideal one-dimensional linear light beam along the line width direction of the one-dimensional linear light spot, obtaining at least two one-dimensional linear light beams 5. That is to say, the one-dimensional linear light beam array actually finally projected by the metalens 1 does not include the directly emerging ideal one-dimensional linear light beam 5. At this time, all the one-dimensional linear light beams 5 are distorted. Finally, all the one-dimensional linear light spots 6 projected on the target plane 3 are not ideal one-dimensional linear light spots, with certain curvatures at both ends in the x-axis direction. Moreover, there is no light spot at y = 0 on the target plane, as Figure 3 and Figure 4 shown.

[0051] Furthermore, the shaping phase of the metalens 1 is obtained by geometric calculation based on the incident light intensity distribution and the target light intensity distribution. The light beam 4 emitted by the light source 2 irradiates on the metalens 1, having a corresponding incident light intensity distribution. If the light beam 4 is only modulated and output by the metalens 1 under the action of the shaping phase of the metalens 1, the ideal one-dimensional linear light spot formed on the target plane 3 also has a corresponding target light intensity distribution. It should be noted that the geometric method refers to the method for calculating the metalens phase derived from the one-dimensional form of the generalized Snell's law. In fact, it is to calculate the phases of each position on the metalens 1 in the two dimensions of the x-axis and the y-axis respectively through the one-dimensional form of the generalized Snell's law, and then superimpose the phases in the two dimensions to obtain the shaping phase of the metalens 1.

[0052] The replication phase of the metalens 1 is optimized by the GS (Gerchberg - Saxton Algorithm); the GS algorithm is a phase retrieval algorithm, and its principle is to restore the corresponding phase distribution through the known light intensity distribution on the object plane and the light intensity distribution on the observation plane.

[0053] In one embodiment, the shaping phase of the metalens 1 is also used to expand the light beam 4 in the line length direction of the one-dimensional linear light spot 6.

[0054] Specifically, referring to Figure 2 , the line length direction of the one-dimensional linear light spot 6 is the x-axis direction of the two-dimensional plane where the metalens 1 is located. That is to say, the metalens 1 will expand the light beam 4 in the x-axis direction of its two-dimensional plane, so that the one-dimensional linear light beam obtained by modulating the metalens 1 can be longer in the x-axis direction, making the light spot formed by the one-dimensional linear light beam more slender in the x-axis direction, thereby being able to be used to detect objects or planes with larger sizes, broadening the application scenarios of the metalens 1.

[0055] In one embodiment, the light beam 4 received by the metalens 1 is a non-collimated light beam. For the non-collimated light beam 4, therefore, the phase of the metalens 1 further includes a collimation phase for collimating the light beam 4.

[0056] Furthermore, the collimation phase provided by the metalens 1 can be used to collimate the light beam 4 in the line length direction and the line width direction of the one-dimensional line spot 6. In this embodiment, the collimation phase of the metalens 1 satisfies:

[0057]

[0058] Where is the collimation phase, x and y are the coordinates of the metalens 1 in its two-dimensional plane, f is the focal length of the metalens 1, and k is the wave number. In this case, collimation of the light beam 4 in both the line length direction and the line width direction can be achieved simultaneously, thereby enabling precise modulation of the line width of the finally formed one-dimensional line spot 6, and improving the edge steepness of the edge region of the one-dimensional line spot 6 projected by the metalens 1 in the line length direction, effectively improving the light energy utilization rate of the sine line array spot.

[0059] In one embodiment, the light beam 4 received by the metalens 1 is a non-collimated light beam. For the non-collimated light beam 4, if the requirement for the light energy utilization rate in the line length direction of the sine line array spot is not high in actual requirements, the metalens 1 can also be designed to provide only the collimation phase in the line width direction, and only collimate the light beam 4 in the line width direction, thereby facilitating improvement of the line width quality of the formed one-dimensional line spot 6. In this case, when designing the collimation phase of the metalens 1, only the collimation phase in the line width direction needs to be designed, simplifying the design process of the metalens 1, reducing the design difficulty of the metalens 1, and improving the production efficiency.

[0060] In another embodiment, the light beam 4 received by the metalens 1 is a collimated light beam or a light beam with a small divergence angle. In this case, the metalens 1 does not need to provide a collimation phase to collimate the light beam 4, and the metalens 1 only needs to provide a shaping phase and a replication phase to project a sine line array spot.

[0061] The present application provides a transmitting device, the transmitting device includes: a light source 2; the metalens 1 as described in the above embodiment.

[0062] Specifically, the metalens 1 is disposed on the light-emitting side of the light source 2, so that the metalens 1 can receive the light beam 4 emitted by the light source 2 and modulate the light beam 4 into multiple one-dimensional line light beams 5, thereby forming multiple one-dimensional line spots 6 on the target plane 3.

[0063] In one embodiment, the light source 2 can be an EEL (Edge-Emitting Laser) light source.

[0064] In one embodiment, the light source 2 can also be a VCSEL (Vertical-Cavity Surface-Emitting Laser) light source.

[0065] This application provides a lidar, which includes: a transmitting device as described in the above embodiment; a receiving device.

[0066] Specifically, the lidar projects a sine line array light spot on the object to be detected or the target plane to be detected through the transmitting device, and scans the object to be detected or the target plane to be detected through the sine line array light spot; the receiving device of the lidar then obtains the three-dimensional information of the object to be detected or the target plane to be detected through the characteristics of the sine line array light spot, so as to realize the detection of the object to be detected or the target plane to be detected.

[0067] Embodiment

[0068] See Figures 5 to 7 , Figure 5 shows an overview of the light intensity distribution of the sine line array light spot projected by the transmitting device provided in an embodiment of this application, Figure 6 shows a partial view of the light intensity distribution of the sine line array light spot projected by the transmitting device provided in an embodiment of this application, Figure 7 shows a cross-sectional view of the central light intensity distribution along the line width direction of the sine line array light spot projected by the transmitting device provided in an embodiment of this application. In this embodiment, the light source 2 is an 850 nm EEL light source, the number of light spots of the sine line array light spot is 256, the inscribed FOI (Field Of Illumination) of the sine line array light spot is 80°×60° (V×H, vertical direction × horizontal direction), the distance between the target plane 3 and the meta-lens 1 in the transmitting device is 0.5 m, and the angle between adjacent one-dimensional line beams is 0.18°. It should be noted that, as shown at the position where y = 0 in Figure 6 , the sine line array light spot in this embodiment does not include an ideal one-dimensional line light spot without distortion, and the sine line array light spot in this embodiment is symmetric both in the line length direction and in the line width direction of the one-dimensional line light spot; and as shown in Figure 7 , the central light intensity along the line width direction of each one-dimensional line light spot is almost the same, and the curve of the cross-sectional view of the light intensity distribution is approximately a sine function curve.

[0069] Those skilled in the art will readily conceive of other embodiments of the present application after considering the specification and practicing the utility model disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present application, which follow the general principles of the present application and include well-known knowledge or conventional technical means in the technical field not disclosed in the present application. The specification and examples are only regarded as exemplary, and the true scope and spirit of the present application are pointed out by the appended claims.

Claims

1. A metalens for three-dimensional sensing, characterized in that: The superlens comprises: a substrate and a micro-nano structure arranged on the substrate; The super lens is used to shape the light beam received by it into at least two inline light beams; each inline light beam is used to form a corresponding inline light spot on the target plane, and all the inline light spots are combined into a sinusoidal line array light spot; Wherein, the light intensity distribution of the sinusoidal linear array light spot in the central cross section in the line width direction of the in-line light spot is sinusoidal distribution.

2. The metalens according to claim 1, characterized in that In the sinusoidal linear array light spots, any two adjacent straight line light spots form a group of adjacent light spots; In the line width direction of the word line light spot, the center distances between any two groups of adjacent light spots are equal.

3. The metalens according to claim 2, characterized in that The angle between adjacent line light beams corresponding to the adjacent light spots is greater than or equal to 0.05° and less than or equal to 45°.

4. The metalens according to claim 1, wherein: The sinusoidal linear array light spot is symmetrical about a central axis of the line light spot parallel to the line width direction.

5. The metalens according to claim 1, wherein: The phase of the metalens includes a shaping phase and a copy phase; the shaping phase is used at least to compress the light beam received by the metalens in the line width direction of a word line spot to obtain the word line light beam; the copy phase is used to copy the word line light beam in the line width direction of the word line spot to form a word line light beam array.

6. The superlens according to claim 5, characterized in that The shaping phase is also used to expand the light beam received by the super lens in the line length direction of a word line spot.

7. The metalens according to claim 1, wherein: The phase of the metalens also includes a collimation phase for collimating the light beam received by the metalens.

8. A launching device, characterized in that: The emitting device comprises: a light source; a super lens as claimed in any one of claims 1 to 7; The super lens is arranged on the light emitting side of the light source.

9. The transmitting device according to claim 8, characterized in that: The light source is an EEL light source or a VCSEL light source.

10. A laser radar, characterized in that: The laser radar includes: a transmitting device as described in any one of claims 8-9; and a receiving device.

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