Monolithic optical device for generating linear light spot array and laser radar

Abstract

The utility model provides a monolithic optical device for generating a linear light spot array and a laser radar, and relates to the technical field of super-lens scanning imaging. The monolithic optical device comprises a monolithic super lens; the super lens is used for shaping an incident light beam into a plurality of straight line light beams, so that the plurality of straight line light beams are respectively projected to a receiving surface on a light emitting side of the super lens, a plurality of straight line light spots are formed on the receiving surface, and the plurality of straight line light spots are mutually spaced and parallel; the super lens comprises a plurality of subareas, and each subarea is used for shaping and outputting a linear light beam; the projection of the linear light spot on the plane where the super lens is located is parallel to the boundary between the adjacent subareas. According to the device, collimation and shaping of the light beams can be achieved only through the single super lens so as to form a linear light spot array, the scanning speed of 3D scanning devices such as laser radar can be increased, the size and weight of the device are reduced, and the assembly cost is reduced.

Description

Technical Field

[0001] The present disclosure relates to the technical field of superlens scanning imaging, and in particular to a monolithic optical device and a laser radar for generating a line light spot array. Background Art

[0002] With the continuous development of science and technology, the application of 3D scanning technology is becoming more and more extensive. For example, laser radar can project a straight line of light spot as a marking line to scan objects or environments. Figure 1 and Figure 2 As shown in the figure, when the laser radar projects one straight line of light spots, the viewing angle of the laser radar needs to rotate up and down 30° to scan the entire object or environment. When the laser radar projects seven straight line of light spots, the viewing angle of the laser radar only needs 5° to complete the scan. It can be seen that projecting a straight line of light spot array has a smaller rotation angle than projecting a straight line of light spot, thereby speeding up the scanning speed.

[0003] In the prior art, an optical device consisting of two conventional lenses and a diffractive optical element is used to realize a line light spot array to speed up the scanning speed of the laser radar. Among them, the first conventional lens 01 is used to collimate the incident light beam, the second conventional lens 02 is used to expand the collimated light beam into a line light beam, and the diffractive optical element 03 is used to diffract a line light beam into multiple line light beams and project a line light spot array on the receiving surface, such as Figure 3 shown.

[0004] However, the optical device composed of three lenses must be large in size and heavy in weight, and the assembly cost will be relatively high. Therefore, how to make the optical device used to generate a line spot array miniaturized and lightweight has become a difficult but urgent problem to solve. Utility Model Content

[0005] In order to solve the problems in the prior art, the present disclosure provides a monolithic optical device and a laser radar for generating a line light spot array. The monolithic optical device for generating a line light spot array provided by the present disclosure is more compact and lightweight, and further reduces the assembly cost.

[0006] The first aspect of the present disclosure provides a monolithic optical device for generating a line light spot array. The optical device includes a monolithic super lens; the super lens includes a substrate and a micro-nano structure disposed on the surface of the substrate;

[0007] The metalens is used to shape the incident light beam into a plurality of straight line light beams, so that the plurality of straight line light beams are respectively projected onto a receiving surface located at the light exiting side of the metalens, and a plurality of straight line light spots are formed on the receiving surface, wherein the plurality of straight line light spots are spaced apart from each other and parallel to each other;

[0008] The super lens includes a plurality of partitions, each of which is used to shape and output a straight line light beam; the projection of the straight line light spot on the plane where the super lens is located is parallel to the dividing line between adjacent partitions.

[0009] Optionally, the total amount of light energy received by each partition in the metalens is the same; the areas of the multiple partitions are configured so that the light intensity of the incident light beam received by each partition is the same, so that the energy of the multiple straight-line light beams is the same.

[0010] Optionally, the number of the line beams obtained by shaping the output of the superlens is the same as the number of the partitions.

[0011] Optionally, the phase provided by the metalens includes a collimating phase for collimating an incident light beam.

[0012] Optionally, the incident beam comes from a point light source, and the collimated phase satisfies:

[0013]

[0014] Among them, x is the coordinate value of the micro-nano structure relative to the center of the superlens on the x-axis of the plane where the superlens is located; y is the coordinate value of the micro-nano structure relative to the center of the superlens on the y-axis of the plane where the superlens is located; f is the focal length of the superlens, and k is the wave number.

[0015] Optionally, the metalens provides shaping phases in multiple partitions respectively; the shaping phase is used to compress the incident light beam received in the corresponding partition at least in the line width direction of the word line spot.

[0016] Optionally, the shaping phase is also used to expand the incident light beam received in the corresponding partition in the line length direction of the word line spot.

[0017] Optionally, the shaping phase is obtained by applying a two-dimensional geometric method according to the light intensity distribution received by each partition and the target light intensity distribution of the line light beam shaped and outputted corresponding to each partition.

[0018] Optionally, a light source is also included to provide an incident light beam.

[0019] A second aspect of the present disclosure provides a laser radar, the laser radar comprising a monolithic optical device as described in any of the above technical solutions, and a rotating device;

[0020] The rotating device is used to rotate the monolithic optical device so as to perform detection scanning on each straight line light beam outputted by the super lens.

[0021] The technical solution in this disclosure can produce the following beneficial effects:

[0022] The present invention partitions a single metalens according to the number of target line light spots determined according to design requirements, so that an incident light beam can form a required plurality of line light spots through the metalens partitions, that is, form a line light spot array.

[0023] At the same time, since the optical device provided by the present invention realizes a line light spot array through a single-piece super lens, the overall volume and weight of the device are more compact and lightweight than the optical device composed of three lenses in the prior art, which further reduces the assembly cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The accompanying drawings illustrate embodiments of the present disclosure and together with the following description serve to explain the principles of the present disclosure.

[0025] Figure 1 A schematic diagram showing a laser radar generating a line beam for scanning;

[0026] Figure 2 A schematic diagram showing a laser radar generating multiple beams for scanning;

[0027] Figure 3 A schematic diagram of an optical device for generating a line light spot array through three lenses in the prior art is shown;

[0028] Figure 4 A schematic diagram of an optional device for generating a word line light spot array provided by the present disclosure is shown;

[0029] Figure 5 A schematic diagram showing the area configuration of three partitions of the metalens provided by the present disclosure is shown;

[0030] Figure 6 The Gaussian light source radius provided by the present disclosure is 50 (according to e -2 Calculation), schematic diagram of the metalens being divided into three equal parts according to the beam energy when the metalens is a square with a side length of 200 μm;

[0031] Figure 7 A schematic diagram showing a metalens provided by the present disclosure applying a two-dimensional geometric method and performing phase shaping on an incident light beam based on an incident light intensity distribution and a target light intensity distribution of the incident light beam;

[0032] Figure 8 A schematic diagram of a metalens phase design process for generating a line spot array provided by the present disclosure is shown;

[0033] Fig. 9 A schematic diagram of an embodiment of generating 11 light spots of a word line provided by the present disclosure is shown;

[0034] Fig.10 A schematic diagram showing a light source and an optical device provided by the present disclosure combined to generate 11 straight-line light spots;

[0035] Fig.11 A schematic diagram of an embodiment of generating 7 one-word line light spots provided by the present disclosure is shown;

[0036] Fig.12 A schematic diagram showing a light source and an optical device provided by the present disclosure combined to generate 7 straight-line light spots;

[0037] Fig.13 A schematic diagram of an embodiment of generating five one-line light spots provided by the present disclosure is shown;

[0038] Fig.14 A schematic diagram showing a combination of a light source and an optical device provided by the present disclosure to generate five straight-line light spots.

[0039] The reference numerals in the figure represent respectively:

[0040] 01: first conventional lens; 02: second conventional lens; 03: optical diffraction element;

[0041] 10: light source; 20: super lens; 30: receiving surface; 40: straight line beam;

[0042] 50: Line light spot;

[0043] 1: first partition; 2: second partition; 3: third partition. DETAILED DESCRIPTION

[0044] The present disclosure will now be described more fully below with reference to the accompanying drawings, in which various embodiments are shown. However, the present disclosure can be implemented in many different ways and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure will be exhaustive and complete, and will fully convey the scope of the present disclosure to those skilled in the art. The same reference numerals throughout the text represent the same components. Furthermore, in the accompanying drawings, the thickness, ratios, and sizes of the components are exaggerated for clarity.

[0045] The terms used herein are only used for the purpose of describing specific embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, "one", "the", "at least one" as used herein do not represent a limitation on quantity, but are intended to include both the singular and the plural. For example, unless the context clearly indicates otherwise, "a component" has the same meaning as "at least one component". "At least one" should not be interpreted as being limited to the number "one". "Or" means "and / or". The term "and / or" includes any and all combinations of one or more of the associated listed items.

[0046] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meanings as those generally understood by those skilled in the art. Terms defined in commonly used dictionaries should be interpreted as having the same meanings as in the relevant technical context, and unless clearly defined in the specification, these terms are not interpreted as having formal meanings in an idealized or overly formal sense.

[0047] The meaning of “include” or “comprising” specifies properties, quantities, steps, operations, components, parts or a combination thereof, but does not exclude other properties, quantities, steps, operations, components, parts or a combination thereof.

[0048] Embodiments are described herein with reference to cross-sectional views as idealized embodiments. Thus, variations in shape relative to the illustrated diagram are anticipated as a result of, for example, manufacturing techniques and / or tolerances. Therefore, the embodiments described herein should not be interpreted as being limited to the specific shapes of the regions as shown herein, but should include deviations in shape due to, for example, manufacturing. For example, a region shown or described as flat may typically have rough and / or nonlinear features. Moreover, the sharp angles shown may be rounded. Therefore, the regions shown in the figures are schematic in nature, and their shapes are not intended to illustrate the precise shape of the regions and are not intended to limit the scope of the claims.

[0049] In order to solve the problems in the background technology, the prior art also uses multiple metalenses to replace traditional lenses to collimate, expand, replicate or diffract the light beam, thereby forming a line array of light spots on the receiving surface. Since the metalenses are light, thin, simple and cheap, the volume and weight of the optical device using multiple metalenses are reduced compared to the optical device composed of traditional lenses, and its assembly cost will also be relatively reduced.

[0050] However, since there is a certain distance between multiple metalenses during assembly, the effect of using multiple metalenses to replace traditional lenses to miniaturize and lighten optical devices is not obvious.

[0051] The present disclosure provides a monolithic optical device for generating a line light spot array and a laser radar that can well solve the above-mentioned problems. In the following, exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0052] like Figure 4 As shown, the first aspect of the present disclosure provides a monolithic optical device for generating a line light spot array, the monolithic optical device comprising a monolithic metalens 20; wherein the metalens 20 comprises a substrate and a micro-nano structure arranged on the surface of the substrate. The metalens 20 comprises a plurality of partitions. For example, the metalens 20 is partitioned by the light intensity distribution of the incident light beam incident on the metalens 20 so that the light intensity received by each partition is the same. Each partition is used to shape and output a line light beam 40 respectively. Specifically, each partition can be incident on the partition through the light intensity distribution of the incident light beam and the target light intensity distribution, and the shaping phase of each partition is obtained based on the two-dimensional geometric method. When the incident light beam passes through each partition of the metalens 20, it can be shaped into a line light beam 40 corresponding to each partition, and a line light spot 50 is formed on the receiving surface 30. The projection of the line light spot 50 on the plane where the metalens 20 is located is parallel to the dividing line between adjacent partitions. In a preferred embodiment, as Figure 4 As shown, the metalens 20 includes a first partition 1, a second partition 2 and a third partition 3, the dotted line between the first partition 1 and the second partition 2 is the dividing line between the first partition 1 and the second partition 2, the dotted line between the second partition 2 and the third partition 3 is the dividing line between the second partition 2 and the third partition 3, and when a line light spot 50 is projected on the plane where the metalens 20 is located, the projection of the line light spot is parallel to the dividing line between adjacent partitions on the same plane. In the embodiment of the present application, Figure 4 , Figure 5 and Figure 7 The dotted circle inside the super lens 20 is the light intensity distribution of the incident light beam on the super lens 20.

[0053] Specifically, the super lens 20 is used to shape the incident light beam from the light source 10 into a plurality of straight line light beams 40, so that the plurality of straight line light beams 40 are respectively projected onto the receiving surface 30 located on the light exiting side of the super lens 20, and a plurality of straight line light spots 50, i.e., a target straight line light spot array, are formed on the receiving surface 30. The plurality of straight line light spots 50 are spaced apart from each other and parallel to each other. In some optional embodiments, the light source 10 is a single point light source; in some optional embodiments, the light source 10 includes a plurality of point light sources.

[0054] The present disclosure provides a monolithic optical device for generating a line light spot array, which can realize the line light spot array by using a monolithic metalens through partitioning. Compared with the solution of using multiple traditional lenses, the optical device that uses a monolithic metalens to realize the line light spot array is small in size, light in weight, and reduces the assembly cost. Compared with the solution of multiple metalens, the optical device provided by the present disclosure not only saves the space between multiple lenses when assembling multiple lenses, but also the monolithic metalens has a significant effect of miniaturizing and lightweighting the optical device compared to multiple metalens, further reducing the volume and weight of the optical device, reducing the assembly cost, thereby realizing the miniaturization and lightweighting of the optical device.

[0055] In an optional embodiment, the incident light beam of the metalens 20 is collimated light, and the metalens 20 does not need to provide a collimation phase to collimate the incident light beam. In another optional embodiment, the incident light beam of the metalens 20 is non-collimated light, and the entire metalens 20 is used to collimate the incident light beam. The incident light beam comes from a point light source, and the collimation phase of the metalens 20 used to collimate the incident light beam satisfies:

[0056]

[0057] in, is the collimation phase of the superlens 20, x is the coordinate value of the phase distribution center of the micro-nano structure relative to the superlens 20 on the x-axis of the plane where the superlens 20 is located; y is the coordinate value of the phase distribution center of the micro-nano structure relative to the superlens 20 on the y-axis of the plane where the superlens 20 is located; f is the focal length of the superlens 20, and k is the wave number.

[0058] According to an embodiment of the present disclosure, the metalens 20 is configured to include a plurality of partitions. Optionally, the number of partitions is consistent with the number of the word line light spots 50. For example, if the number of target word line light spots is 3, then the number of partitions of the metalens 20 can be set to 3, and the formed word line light spots 50 are parallel to the boundary lines of the partitions. Preferably, along the direction in which the word line light spots 50 are arranged on the receiving surface 30, the order of the word line light spots corresponds to the order of the partitions one by one. Through the aforementioned partition design, the incident light beam can be divided into a plurality of sub-beams. Among them, the energies of the plurality of sub-beams may be the same or different.

[0059] In an optional embodiment, the number of the multiple partitions included in the metalens 20 is different from the number of the line light spots. Specifically, when the receiving surface 30 is fixed, that is, the working distance is fixed, the line light beams shaped and output by the multiple partitions can overlap at the working distance, so that the line light beams output by the multiple partitions project a line light spot with superimposed light intensity at the working distance, so that the multiple partitions generate a line light spot.

[0060] Optionally, the total amount of light energy received by each partition in the metalens 20 is the same, and the areas of the multiple partitions are configured so that the light intensity of the incident light beam received by each partition is the same, so that the energy of the light beam emitted by each partition is the same. When the light intensity distribution of the incident light beam shows the characteristics of strong in the middle and weak at the edges, the area of ​​any one of the multiple partitions is positively correlated with the distance between the geometric center of the partition and the geometric center of the metalens. For example, Figure 5 As shown in FIG. 1 , when the number of metalens partitions is 3 and the incident beam is a Gaussian beam, the closer the incident beam is to the center, the stronger the energy is. The incident beam is divided into 3 sub-Gaussian beams by the metalens and incident on the first partition 1, the second partition 2 and the third partition 3 respectively. If the first partition 1, the second partition 2 and the third partition 3 are equally divided by area, then the energy in the second partition 2 will be stronger than that in the first partition 1 and the third partition 3. Therefore, the areas of the first partition 1 and the third partition 3 must be larger than the second partition 2 to ensure that the energies in the first partition 1, the second partition 2 and the third partition 3 are equal, as shown in FIG. Figure 6 As shown, the figure shows that the Gaussian beam radius is 50 (by e -2 Calculation), schematic diagram of dividing the beam energy into three equal parts when the metalens is a square with a side length of 200 μm.

[0061] In the disclosed embodiment, the metalens 20 is further configured to provide shaping phases in the plurality of partitions. Specifically, the shaping phase can compress the light beam incident on the metalens 20 in the line width direction and expand it in the line length direction, so that the light spot on the receiving surface 30 presents a straight line shape.

[0062] According to the embodiment of the present disclosure, Figure 7 As shown, taking the three-dimensional coordinate system in the figure as a reference, the direction of light path propagation is taken as the z-axis, the direction perpendicular to the z-axis in the horizontal plane is taken as the x-axis, and the direction perpendicular to the x-axis and the z-axis in the vertical plane is taken as the y-axis. In the embodiment of the present disclosure, the light intensity distribution of each sub-beam incident on the plane where the super lens 20 is located is the incident light intensity distribution I 1i (x1, y1), the light intensity distribution of each sub-beam incident on the receiving surface 30 is the target light intensity distribution I 2i (x2, y2). Based on the above embodiment, the shaping phase φ of each partition si (x, y) is configured according to the incident light intensity distribution I of the sub-beam corresponding to the partition 1i (x1, y1) and target light intensity distribution I 2i (x2, y2), and obtain it by applying the two-dimensional geometric method. Among them, the target light intensity distribution I 2i (x2, y2) is the light intensity distribution of the target line spot. Finally, the shaping phase φ of the entire super lens 20 is sis configured as a shaping phase φ for each partition si (x, y) is synthesized.

[0063] It should be noted that the two-dimensional geometric method is a method for calculating the phase of a metalens by extending the one-dimensional form of the generalized Snell's law into a two-dimensional form. Figure 7 As shown, taking the three-dimensional coordinate system in the figure as a reference, the direction of light path propagation is taken as the z-axis, the direction perpendicular to the z-axis in the horizontal plane is taken as the x-axis, and the directions perpendicular to the x-axis and the z-axis are taken as the y-axis. After being modulated by the super lens 20, the incident light beam will obtain a first deflection angle α and a second deflection angle β. Based on the first and / or second deflection angles and by using the generalized Snell's law, the deflection phase of the outgoing light beam at each location is calculated.

[0064] Specifically, the one-dimensional geometric method is often used to determine the shaping phase of the metalens, which refers to a method for calculating the metalens phase derived from the one-dimensional form of the generalized Snell's law.

[0065] Optionally, the shaping phase of each partition is configured to at least compress the sub-beam received in the corresponding partition in the line width direction of the word line beam 40. The shaping phase of each partition is also configured to expand the sub-beam received in the corresponding partition in the line length direction of the word line beam 40.

[0066] According to the above embodiment, the overall phase of the whole metalens 20 satisfy:

[0067]

[0068] in, is the collimation phase of the superlens 20; is the shaping phase of the super lens 20.

[0069] The present disclosure also provides a method for calculating the phase of a superlens for generating a word line spot array, such as Figure 8 As shown, the steps include:

[0070] S1. Obtain the collimation phase of the metalens 20 according to the incident light beam and formula (1).

[0071] S2. Partition the superlens 20.

[0072] Optionally, the number of partitions is determined according to the number of array copies of the word line light spot array. Wherein, along the arrangement direction of the word line light spot 50, the word line light spot 50 corresponds to the partition one by one. Optionally, the area of ​​the partition is determined according to the target light intensity distribution of the word line light spot 50. Wherein, the area of ​​the partition is evenly distributed according to the energy of the incident light beam incident on each partition, so that the light intensity distribution of the word line light spot 50 is more uniform.

[0073] S3. Obtain the shaping phase of the superlens 20.

[0074] In the embodiment of the present disclosure, after determining the number of partitions and the area of ​​each partition, the shaping phase of each partition needs to be adjusted so that the sub-beams corresponding to each partition can be shaped into a line beam 40. Optionally, the shaping phase of each partition is obtained based on the incident light intensity distribution and the target light intensity distribution and based on the two-dimensional geometric method. Then, the shaping phase of the metalens 20 is obtained by synthesizing the shaping phase of each partition.

[0075] S4. The overall phase calculation of the metalens is completed by superimposing the collimated phase on the shaped phase.

[0076] In summary, the incident light beam is collimated by the collimation phase of the metalens 20, and the metalens 20 is partitioned according to the number of target line light beams and the light beam energy received by each partition. At the same time, according to the incident light intensity distribution of the sub-beams passing through each partition and the target light intensity distribution, a two-dimensional geometric method is applied to obtain the shaping phase of each partition, so as to obtain a plurality of line light beams 40 after collimation and shaping, thereby obtaining a line light spot array of the plurality of line light beams 40 projected on the receiving surface 30.

[0077] A second aspect of the present disclosure provides a laser radar, comprising the aforementioned technical solution and a monolithic optical device for generating a line array of any optional solution, and a rotating device; wherein the rotating device is used to rotate the monolithic optical device to perform detection scanning on each line light beam 40 obtained by shaping the output through the super lens 20.

[0078] The following are specific embodiments provided by the present disclosure:

[0079] Example 1

[0080] The light source 10 is a single point light source with a divergence angle of 20° (based on the peak value of e -2 The light source 10 is a Gaussian light source with a full angle of 20° (calculated at the intensity point), and the distance between the light source 10 and the metalens 20 is 2 mm; the size of the metalens 20 is 1.5 mm × 1.5 mm (V × H, V is the vertical direction (i.e. Vertical), H is the horizontal direction (i.e. Horizontal), and the focal length is 2 mm; the number of target straight line spots is 11, and the observation distance (i.e. the distance between the receiving surface 30 and the metalens 20) is 2 m. Therefore, the metalens 20 is divided into 11 blocks, wherein the dividing lines between each block are -236 μm, -161 μm, -108 μm, -62 μm, -21 μm, 21 μm, 62 μm, 108 μm, 161 μm and 236 μm, respectively. The schematic diagram of the area division of the light source 10 on the metalens 20 after being divided by each block is shown in FIG. Fig. 9 As shown in FIG. 1 , the metalens 20 of this configuration projects a straight line beam 40 with 11 lines spaced 10° apart, and the emission angle (FOI, Field of Illumination) in the beam expansion direction is 110°. The above embodiment can generate and observe a straight line array of light spots, such as Fig.10 shown.

[0081] Example 2

[0082] The light source 10 uses a divergence angle of 24°×12° (based on the peak e -2 The intensity is calculated at the full angle of 20°, V×H) EEL light source, the distance between the light source 10 and the metalens 20 is 1.8mm; the size of the metalens 20 is 1.5mm×0.6mm (V×H), and the focal length is 1.8mm; the number of target straight line spots is 7, and the observation distance (i.e., the distance between the receiving surface 30 and the metalens 20) is 2m. Therefore, the metalens 20 is divided into 7 blocks, where the dividing lines between each block are -206μm, -110μm, -35μm, 35μm, 110μm and 206μm respectively. The schematic diagram of the area division of the light source 10 on the metalens 20 after being divided by each block is as follows Fig.11 As shown in FIG. 1 , a line beam 40 with 7 lines spaced 15° is projected from the configured super lens 20, and the FOI in the beam expansion direction is 110°. The above embodiment can generate and observe a line beam array such as Fig.12 shown.

[0083] Example 3

[0084] The light source 10 uses a divergence angle of 20°×6° (based on the peak e -2 The intensity is calculated at the full angle of 20°, V×H) EEL light source, the distance between the light source 10 and the metalens 20 is 1.6mm; the size of the metalens 20 is 1.5mm×0.5mm (V×H), the focal length is 1.6mm; the number of target straight line spots is 5, and the observation distance (i.e. the distance between the receiving surface 30 and the metalens 20) is 2m. Therefore, the metalens 20 is divided into 5 blocks, where the dividing lines between each block are -120μm, -36μm, 36μm and 120μm respectively. The schematic diagram of the area division of the light source 10 on the metalens 20 after being divided by each block is as follows Fig.13 As shown in FIG. 1 , the metalens 20 of this configuration projects a line beam with 5 lines spaced 15° apart, and the FOI in the beam expansion direction is 110°. The above embodiment can generate and observe a line spot array such as Fig.14 shown.

[0085] The disclosed embodiment also provides a metasurface, which includes a superlens. The superlens is composed of a substrate and a nanostructure disposed on the substrate. In the disclosed embodiment, the nanostructure is an all-medium structural unit with high transmittance in the visible light band, and the optional materials of the nanostructure may include: one or more of silicon nitride, titanium oxide, gallium nitride, gallium phosphide and hydrogenated amorphous silicon. The nanostructure may be a polarization-dependent structure, such as nanofins and nanoelliptical columns, which impose a geometric phase on the incident light; the nanostructure may also be a polarization-independent structure, such as nanocylinders and nanosquare columns, which impose a propagation phase on the incident light.

[0086] In the above embodiments, the nanostructures are arranged periodically and form a superstructure unit, which is a densely packed figure, such as a square, a hexagon or a fan, etc., each period contains a group of nanostructures, and the vertices and / or centers of the superstructure unit can be provided with nanostructures, for example. In the case where the superstructure unit is a regular hexagon, at least one nanostructure is provided at each vertex and center of the regular hexagon. Or, in the case where it is a square, at least one nanostructure is provided at each vertex and center of the square. Ideally, the superstructure unit should be a nanostructure arranged at the vertices and center of the hexagon, or a nanostructure arranged at the vertices and center of the square. It should be understood that the actual product may be limited by the shape of the superlens, and there is a lack of nanostructures at the edge of the superlens, so that it does not meet the complete hexagon / square. Specifically, the superstructure unit is formed by the nanostructures arranged in a regular pattern, and a number of superstructure units are arranged in an array to form a supersurface structure.

[0087] According to an embodiment of the present disclosure, the optional structure of the superstructure unit includes a central nanostructure and four peripheral nanostructures surrounding it and having equal distances therefrom, forming a square.

[0088] According to an embodiment of the present disclosure, the optional structure of the above-mentioned superstructure unit includes a central nanostructure and 6 peripheral nanostructures surrounding it at equal distances from it. The peripheral nanostructures are evenly distributed along the circumference to form a regular hexagon, which can also be understood as a combination of regular triangles composed of multiple nanostructures.

[0089] It should be noted that the metalens provided in the embodiments of the present disclosure can be processed by semiconductor technology, and has the advantages of light weight, thin thickness, simple structure and process, low cost and high consistency in mass production.

[0090] In summary, the optical device and laser radar for producing a line array provided by the present invention can collimate the incident light beam through the collimation phase of the metalens, and partition the metalens according to the number of target line beams. At the same time, according to the incident light intensity distribution of the sub-beams passing through each partition and the target light intensity distribution, a two-dimensional geometric method is applied to obtain the shaping phase of each partition, so as to obtain a plurality of collimated and shaped line beams, thereby obtaining a line spot array of the plurality of line beams projected on the receiving surface.

[0091] At the same time, the present invention realizes that a monolithic superlens produces a straight line light spot array by using a monolithic superlens for partitioning, thereby reducing the volume and weight of the optical device, reducing the manufacturing cost of the device, and thus realizing the miniaturization and lightweight of the optical device.

[0092] The above is only a specific implementation of the embodiment of the present disclosure, but the protection scope of the embodiment of the present disclosure is not limited thereto. Any technician familiar with the technical field can easily think of changes or replacements within the technical scope disclosed in the embodiment of the present disclosure, which should be included in the protection scope of the embodiment of the present disclosure. Therefore, the protection scope of the embodiment of the present disclosure should be based on the protection scope of the claims.

Claims

1. A monolithic optical device for generating a line light spot array, characterized in that: A monolithic superlens (20) is provided; the superlens (20) comprises a substrate and a micro-nano structure arranged on the surface of the substrate; The super lens (20) is used to shape an incident light beam into a plurality of straight line light beams (40), so that the plurality of straight line light beams (40) are respectively projected onto a receiving surface (30) located on a light exiting side of the super lens (20), and a plurality of straight line light spots (50) are formed on the receiving surface (30), wherein the plurality of straight line light spots (50) are spaced apart from each other and are parallel to each other; The super lens (20) comprises a plurality of partitions, each of which is used to shape and output a line light beam (40); a projection of the line light spot (50) on the plane where the super lens (20) is located is parallel to a boundary line between adjacent partitions.

2. The monolithic optical device according to claim 1, wherein: The total amount of light energy received by each partition in the metalens (20) is the same; the areas of the multiple partitions are configured so that the light intensity of the incident light beam received by each partition is the same, so that the energy of the multiple straight-line light beams (40) is the same.

3. The monolithic optical device according to claim 1, wherein: The number of the word line light beams (40) obtained by shaping the output of the super lens (20) is the same as the number of the partitions.

4. The monolithic optical device according to claim 1, wherein: The phase provided by the metalens (20) includes a collimating phase for collimating the incident light beam.

5. The monolithic optical device according to claim 4, wherein: The incident light beam originates from a point light source, and the collimated phase satisfies: Wherein, x is the coordinate value of the micro-nano structure relative to the center of the superlens (20) on the x-axis of the plane where the superlens (20) is located; y is the coordinate value of the micro-nano structure relative to the center of the superlens (20) on the y-axis of the plane where the superlens (20) is located; f is the focal length of the superlens (20), and k is the wave number.

6. The monolithic optical device according to claim 1, wherein: The super lens (20) provides shaping phases in the plurality of subareas respectively; the shaping phases are used at least to compress the incident light beam received in the corresponding subarea in the line width direction of the word line light spot (50).

7. The monolithic optical device according to claim 6, wherein: The shaping phase is also used to expand the incident light beam received in the corresponding partition in the line length direction of the word line light spot (50).

8. The monolithic optical device according to claim 6, wherein: The shaping phase is obtained by applying a two-dimensional geometric method according to the light intensity distribution received by each partition and the target light intensity distribution of the word line light beam (40) shaped and outputted corresponding to each partition.

9. The monolithic optical device according to claim 1, wherein: It also comprises a light source (10) for providing the incident light beam.

10. A laser radar, characterized in that: include: The monolithic optical device according to any one of claims 1 to 9, wherein the rotating device; The rotating device is used to rotate the monolithic optical device to perform detection scanning on each line light beam (40) shaped and output by the super lens (20).

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