Superlens for projecting linear light spot, design method thereof and emission system

Abstract

The invention provides a super lens for projecting a linear light spot, a design method of the super lens and an emission system. The super lens provided by the invention comprises a substrate and a micro-nano structure arranged on the substrate, the super lens is used for shaping incident light into a linear light beam, and the linear light beam is used for projecting on a target plane to obtain a linear light spot; the divergence angle of the incident light parallel to the line length direction of the linear light spot is smaller than or equal to the divergence angle of the incident light parallel to the line width direction of the linear light spot. According to the super lens provided by the invention, the direction of the incident light with a larger divergence angle is preferentially used as the parallel direction of the line width direction, so that the beam waist corresponding to the line width direction is effectively reduced, the lower limit of the line width is reduced, and the effective compression of the line width is facilitated.

Description

Technical Field

[0001] The present application relates to the field of optics, and in particular to a super lens for projecting a line of light spots, a design method thereof, and a transmitting system. Background Art

[0002] A straight line beam refers to a beam used to project a straight line of light onto a target plane, and is often used in scenarios such as 3D sensing and positioning identification. The straight line of light is in the shape of a straight line, and the direction parallel to its long side is usually called the line length direction, while the direction parallel to its wide side is usually called the line width direction. In general, various applications such as 3D sensing and positioning identification are mainly achieved based on the light intensity distribution of the straight line beam along the line length direction.

[0003] For a metalens used to project a line of light spots, it is usually necessary to minimize the line width of the line of light spots. However, how to effectively compress the line width of the line of light spots that can be output by the metalens is an urgent problem to be solved in this field. Summary of the invention

[0004] One purpose of the present application is to propose a metalens for projecting a line light spot and a design method and a launch system thereof. The metalens provided in the present application effectively reduces the beam waist corresponding to the line width direction by preferentially taking the direction in which the incident light has a larger divergence angle as the parallel direction of the line width direction, thereby reducing the lower limit of the line width, which is conducive to effectively compressing the line width.

[0005] According to one aspect of an embodiment of the present application, a metalens for projecting a line light spot is disclosed, the metalens comprising a substrate and a micro-nano structure disposed on the substrate; the metalens is used to shape incident light into a line light beam, and the line light beam is used to project the line light spot on a target plane;

[0006] The divergence angle of the incident light parallel to the line length direction of the word line light spot is less than or equal to the divergence angle of the incident light parallel to the line width direction of the word line light spot.

[0007] In an exemplary embodiment of the present application, the effective area of ​​the metalens includes at least one first arched area and at least one second arched area;

[0008] The top of the first arched area faces the second arched area, and the top of the second arched area faces the first arched area.

[0009] In an exemplary embodiment of the present application, the first arched area and the second arched area are symmetrically distributed with respect to the target direction in the two-dimensional plane where the metalens is located, so that a line between the center of the line spot and the center of the effective area is perpendicular to the metalens;

[0010] The target direction is perpendicular to the dome orientation of the dome region.

[0011] In an exemplary embodiment of the present application, the first arched area and the second arched area are asymmetrically distributed with respect to the target direction in the two-dimensional plane where the metalens is located, so that a line between the center of the line spot and the center of the effective area is inclined to the metalens;

[0012] The target direction is perpendicular to the dome orientation of the dome region.

[0013] In an exemplary embodiment of the present application, when the effective area includes at least two first areas, the tops of the first arched areas are oriented in the same direction, and the first arched areas are adjacent to each other in a concentric manner;

[0014] When the effective area includes at least two second areas, the arch tops of the second arch areas are oriented in the same direction, and the second arch areas are adjacent to each other in a concentric manner.

[0015] In an exemplary embodiment of the present application, when designing a shaping phase for shaping the incident light along the line length direction of the word-line light spot, in the target light intensity distribution of the word-line light beam, the number of light intensity data sampling points along the line length direction of the word-line light spot is N times the maximum number of micro-nano structures arranged along the one-dimensional direction in the superlens, and N is greater than or equal to 1.

[0016] In an exemplary embodiment of the present application, N is greater than or equal to 4.

[0017] According to one aspect of an embodiment of the present application, a design method of a metalens for projecting a line of light spots is disclosed, the method comprising:

[0018] Acquiring an initial target light intensity distribution of the line-shaped light beam from design requirement information used to describe the performance of the line-shaped light beam, wherein the line-shaped light beam is used to project a line-shaped light spot on a target plane;

[0019] Reconstructing the initial target light intensity distribution along the line length direction of the line light spot to obtain a reconstructed target light intensity distribution, wherein along the line length direction, the resolution of the reconstructed target light intensity distribution is higher than the resolution of the initial target light intensity distribution;

[0020] Based on the reconstructed target light intensity distribution and the light intensity distribution of the incident light received by the metalens, a shaping phase for shaping the incident light along the line length direction is designed;

[0021] Based on the shaping phase, the micro-nano structures that should be arranged at various positions on the superlens are determined, and the superlens for projecting the line light spot is designed.

[0022] In an exemplary embodiment of the present application, the initial target light intensity distribution is reconstructed along the line length direction of the word line light spot to obtain the reconstructed target light intensity distribution, including:

[0023] Extracting discrete light intensity data from the initial target light intensity distribution along the line length direction;

[0024] According to the discrete light intensity data, a light intensity distribution function is fitted to describe the initial target light intensity distribution along the line length direction;

[0025] The light intensity distribution function is discretized and valued to obtain the reconstructed target light intensity distribution.

[0026] In an exemplary embodiment of the present application, the initial target light intensity distribution is reconstructed along the line length direction of the word line light spot to obtain the reconstructed target light intensity distribution, including:

[0027] Extracting discrete light intensity data from the initial target light intensity distribution along the line length direction;

[0028] The discrete light intensity data is interpolated to obtain the reconstructed target light intensity distribution.

[0029] In an exemplary embodiment of the present application, based on the reconstructed target light intensity distribution and the light intensity distribution of the incident light received by the metalens, a shaping phase for shaping the incident light along the line length direction is designed, including:

[0030] Based on the law of conservation of energy, the light intensity distribution of the incident light is mapped one-to-one with the reconstructed target light intensity distribution along the line length direction, and the light beam exit angle at each position along the line length direction on the metalens is determined based on the mapping result;

[0031] The shaping phase is calculated based on the light beam exit angle at each position on the metalens along the line length direction and the light beam incident angle at each position on the metalens along the line length direction.

[0032] In an exemplary embodiment of the present application, based on the reconstructed target light intensity distribution and the light intensity distribution of the incident light received by the metalens, a shaping phase for shaping the incident light along the line length direction is designed, including:

[0033] constructing the reconstructed target light intensity distribution along the line length direction into a target image used as a target output of a phase recovery algorithm;

[0034] Based on the light intensity distribution of the incident light along the line length direction and the target image, the phase recovery algorithm is applied to obtain the shaped phase.

[0035] In an exemplary embodiment of the present application, the method further includes:

[0036] Based on the distance between the metalens and the light source, a collimation phase is designed to collimate the incident light along the line length direction; the designed phase of the metalens includes the shaping phase and the collimation phase corresponding to the line length direction.

[0037] In an exemplary embodiment of the present application, the method further includes:

[0038] Acquire a target line width of the word line spot from the design requirement information;

[0039] Based on the target line width and the light intensity distribution of the incident light, a line width compression phase is designed to compress the line width of the single-line light spot along the line width direction; the designed phase of the superlens includes the shaping phase and the line width compression phase.

[0040] In an exemplary embodiment of the present application, the line width compression phase is a collimation phase along the line width direction, or is a focusing phase along the line width direction.

[0041] According to one aspect of an embodiment of the present application, an emission system for projecting a line of light spots is disclosed, the emission system comprising: a light source; a super lens as provided in any of the above embodiments;

[0042] The super lens is arranged on the light emitting side of the light source.

[0043] According to one aspect of an embodiment of the present application, an electronic device is disclosed, comprising: one or more processors; and a memory for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the electronic device implements any one of the above method embodiments.

[0044] According to one aspect of an embodiment of the present application, a computer-readable storage medium is disclosed, on which computer-readable instructions are stored. When the computer-readable instructions are executed by a processor of a computer, the computer is caused to execute any one of the above method embodiments.

[0045] In the embodiment of the present application, the metalens is used to shape the incident light into a line beam, and the line beam is used to project a line spot on the target plane; the divergence angle of the incident light parallel to the line length direction of the line spot is less than or equal to the divergence angle of the incident light parallel to the line width direction of the line spot. In the embodiment of the present application, the direction in which the incident light has a larger divergence angle is preferentially used as the parallel direction of the line width direction, thereby effectively reducing the beam waist corresponding to the line width direction and lowering the lower limit of the line width, which is conducive to effectively compressing the line width.

[0046] 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.

[0047] 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

[0048] 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.

[0049] Figure 1 A schematic diagram of the structure of the metalens provided in this application is shown.

[0050] Figure 2 A schematic diagram showing the composition of the effective area of ​​a metalens in one embodiment of the present application is shown.

[0051] Figure 3 The phase distribution diagram of the metalens in one embodiment of the present application is shown.

[0052] Figure 4 A schematic diagram showing the composition of the effective area of ​​a metalens in one embodiment of the present application is shown.

[0053] Figure 5 A schematic diagram showing the arrangement of micro-nano structures along a horizontal one-dimensional direction in an embodiment of the present application is shown.

[0054] Figure 6 A schematic diagram showing the arrangement of micro-nano structures along an inclined one-dimensional direction in an embodiment of the present application is shown.

[0055] Figure 7 A flow chart of a method for designing a metalens for projecting a line of light spots provided in the present application is shown.

[0056] Figure 8 A schematic diagram of the architecture of an emission system for projecting a line of light spots provided in the present application is shown.

[0057] Fig. 9The figure shows a line light spot projected by a line light beam emitted by the line light beam emitting system of Example 1.

[0058] Fig.10 Shows Fig. 9 The light intensity distribution curve of the line spot in the line width direction is shown.

[0059] Fig.11 Shows Fig. 9 The light intensity distribution curve of the line spot in the line length direction is shown.

[0060] Fig.12 The diagram shows a line of light spot projected by a line of light beam emitted by the line of light beam emitting system of Example 2.

[0061] Fig.13 Shows Fig.12 The light intensity distribution curve of the line spot in the line width direction is shown.

[0062] Fig.14 Shows Fig.12 The light intensity distribution curve of the line spot in the line length direction is shown.

[0063] Fig.15 The diagram shows a line of light spot projected by a line of light beam emitted by the line of light beam emitting system of Example 3.

[0064] Fig.16 Shows Fig.15 The light intensity distribution curve of the line spot in the line width direction is shown.

[0065] Fig.17 Shows Fig.15 The light intensity distribution curve of the line spot in the line length direction is shown.

[0066] Fig.18 The light intensity distribution that the line light beam of Example 4 should satisfy along the line length direction is shown.

[0067] Fig.19 The figure shows a line light spot projected by a line light beam emitted by the line light beam emitting system of the fourth embodiment.

[0068] Fig. 20 Shows Fig.19 The light intensity distribution curve of the line spot in the line width direction is shown.

[0069] Fig.21 Shows Fig.19 The light intensity distribution curve of the line spot in the line length direction is shown.

[0070] Fig. 22 A block diagram of a design device for a metalens provided in the present application is shown. DETAILED DESCRIPTION

[0071] 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.

[0072] 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.

[0073] 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.

[0074] On the surface, as long as the metalens converges the incident light along the line width direction of the line spot, as the degree of convergence increases, the line width of the line spot will become smaller and smaller until it is infinitely small. However, in fact, the incident light received by the metalens usually comes from a laser light source, and the light beam emitted by the laser light source has a corresponding waist in all directions, and the waist of the light beam corresponding to the line width direction determines the lower limit of the line width. Therefore, the line width of the line spot that can be output by the metalens cannot be compressed arbitrarily. Therefore, how to effectively compress the line width of the line spot that can be output by the metalens has become an urgent problem to be solved in this field.

[0075] In order to solve the above problems, the present application provides a metalens for projecting a line light spot. The metalens provided in the present application effectively reduces the beam waist corresponding to the line width direction by preferentially taking the direction of the incident light with a larger divergence angle as the parallel direction of the line width direction, thereby reducing the lower limit of the line width, which is conducive to effectively compressing the line width.

[0076] Figure 1Schematic diagram of the structure of the metalens provided in this application is shown. Figure 1 The metalens 1 provided in the present application includes a substrate 11 and a micro-nanostructure 12 disposed on the substrate 11. Each micro-nanostructure 12 can provide a certain phase for the received light beam, so that the received light beam produces a corresponding phase mutation, so that a certain phase gradient is generated at each position on the metalens 1, thereby modulating the light beam at each position.

[0077] In the embodiment of the present application, the metalens 1 is used to shape the incident light into a line beam. After being emitted from the metalens 1, the line beam continues to propagate, and after propagating to the target plane 3 (for example, a wall, the ground, etc.), a line light spot 2 is projected on the target plane 3. Figure 1 In the figure, the x-axis represents the line length direction of the line light spot 2, the y-axis represents the line width direction of the line light spot 2, and the z-axis represents the direction perpendicular to the super lens 2.

[0078] It should be noted that, for a determined incident light, the size of its beam waist in a specific direction is negatively correlated with the size of its divergence angle in that direction; that is, the larger the divergence angle of the incident light in a specific direction, the smaller the beam waist in that direction, and conversely, the smaller the divergence angle of the incident light in a specific direction, the larger the beam waist in that direction.

[0079] As mentioned above, the lower limit of the line width of the straight line spot 2 is actually determined by the beam waist corresponding to the line width direction; the smaller the beam waist corresponding to the line width direction, the smaller the lower limit of the line width of the straight line spot 2. Therefore, in the embodiment of the present application, the direction in which the incident light has a larger divergence angle is preferentially used as the parallel direction of the line width direction, thereby effectively reducing the beam waist corresponding to the line width direction and lowering the lower limit of the line width, which is conducive to effectively compressing the line width.

[0080] Specifically, the incident light received by the metalens 1 may have different divergence angles in different directions, or may have the same divergence angle.

[0081] If the incident light has different divergence angles in different directions, the embodiment of the present application uses the direction in which the incident light has a larger divergence angle as the parallel direction to the line width direction, thereby effectively reducing the beam waist corresponding to the line width direction and lowering the lower limit of the line width. Since the line width direction and the line length direction are two different directions (the line width direction and the line length direction are perpendicular to each other), when the direction in which the incident light has a larger divergence angle is used as the parallel direction to the line width direction, the direction in which the incident light has a smaller divergence angle becomes the parallel direction to the line length direction. Therefore, in this case, the divergence angle of the incident light parallel to the line length direction of the line spot 2 is smaller than the divergence angle of the incident light parallel to the line width direction of the line spot 2.

[0082] If the incident light has the same divergence angle in different directions, then the beam waist in each direction is equal. In the embodiment of the present application, any direction where the divergence angle of the incident light is located can be used as a parallel direction to the line width direction. In this case, the divergence angle of the incident light parallel to the line length direction of the line light spot 2 is equal to the divergence angle of the incident light parallel to the line width direction of the line light spot 2.

[0083] Figure 2 The schematic diagram of the composition of the effective area of ​​the metalens 1 in one embodiment of the present application is shown. The effective area of ​​the metalens 1 refers to the area in the metalens 1 where the micro-nano structure 12 is provided to exert an effective phase modulation effect on the light beam. Figure 2 The rectangular area in the figure exemplarily represents the complete effective area of ​​a metalens 1; it should be noted that the rectangle only exemplarily shows an optional shape of the effective area of ​​the metalens 1 and does not limit the shape of the effective area of ​​the metalens 1 in the present application.

[0084] See also Figure 2 In one embodiment, the effective area of ​​the metalens 1 includes at least one first arched area ( Figure 2 Three first arched regions are shown, namely regions 41a, 41b and 41c) and at least one second arched region ( Figure 2 Three second arched areas are shown, namely, areas 42a, 42b and 42c. The arch of the first arched area faces the second arched area, and the arch of the second arched area faces the first arched area. That is, the arches of the first arched area and the second arched area are arranged opposite to each other.

[0085] It should be noted that the division of the first arch region and the second arch region is determined according to the distribution characteristics of the micro-nano structure 12; the effective area of ​​the metalens 1 is divided into the first arch region and the second arch region by organizing the positions and sizes of each micro-nano structure 12. Specifically, for the metalens 1 provided in this embodiment, whether according to its SEM (Scanning Electron Microscope) image or according to its phase distribution diagram, the composition of the first arch region and the second arch region can be intuitively observed.

[0086] Figure 3 The phase distribution diagram of the superlens 1 in one embodiment of the present application is shown. Figure 3 Different colors in the image represent different phase values, and the mapping relationship between colors and phase values ​​is described by the bars on the right. Figure 3It can be seen intuitively from the phase distribution diagram that the effective area of ​​the corresponding superlens 1 includes two types of arched areas with arch tops facing each other. The arched areas on the left side can be recorded as the first arched areas, and the arched areas on the right side can be recorded as the second arched areas.

[0087] In this embodiment, the first arched area and the second arched area with arches facing each other are arranged in the effective area of ​​the superlens 1 mainly for precisely controlling the eccentricity of the line light spot 2 by controlling the symmetry between the first arched area and the second arched area.

[0088] Specifically, the symmetry between the first arched region and the second arched region describes the symmetry between the first arched region and the second arched region with respect to a target direction. The target direction is located in the two-dimensional plane where the metalens is located and is perpendicular to both the dome orientation of the first arched region and the dome orientation of the second arched region. Figure 2 In the embodiment, the vault orientation of the first vaulted region and the vault orientation of the second vaulted region are both parallel to Figure 2 The horizontal direction of , so the target direction is Figure 2 vertical direction.

[0089] The eccentricity of the line light spot describes the offset property of the line light spot 2 relative to the positive emission direction of the metalens 1. Connect the center of the line light spot 2 with the center of the effective area of ​​the metalens 1 to obtain the corresponding line. If the line is perpendicular to the metalens 1, it means that the line light spot has not deviated from the positive emission direction of the metalens 1, and is an uneccentric line light spot; if the line is inclined to the metalens 1, it means that the line light spot has deviated from the positive emission direction of the metalens 1, and is an eccentric line light spot, and the greater the inclination angle, the greater the degree of eccentricity.

[0090] like Figure 2 As shown, when the first arched area and the second arched area are symmetrically distributed about the target direction, the line between the center of the straight line light spot 2 projected by the superlens 1 and the center of the effective area is perpendicular to the superlens 1; that is, when the first arched area and the second arched area are symmetrically distributed about the target direction, the superlens 1 projects a non-eccentric straight line light spot 2.

[0091] Figure 4 A schematic diagram showing the composition of the effective area of ​​a metalens in one embodiment of the present application is shown. Figure 4 There are two first arched areas, namely areas 41a and 41b, and three second arched areas, namely areas 42a, 42b and 42c; Figure 4 , the first arched area and the second arched area are about the target direction (ie, Figure 4 The vertical direction in the figure shows an asymmetric distribution.

[0092] like Figure 4 As shown, when the first arched area and the second arched area are asymmetrically distributed with respect to the target direction, the line between the center of the straight-line light spot 2 projected by the superlens 1 and the center of the effective area is inclined to the superlens 1; that is, when the first arched area and the second arched area are asymmetrically distributed with respect to the target direction, the superlens 1 projects an eccentric straight-line light spot 2.

[0093] Moreover, the greater the asymmetry between the first arched area and the second arched area with respect to the target direction, the greater the eccentricity of the straight line light spot 2 projected by the super lens 1.

[0094] The symmetric region of the first arched region is obtained after the first arched region is flipped about a target axis parallel to the target direction (the target axis does not intersect the first arched region). Under the premise that the symmetric region of the first arched region can only be translated in a direction perpendicular to the target direction, the minimum difference that can be achieved between the geometric features of the symmetric region of the first arched region and the geometric features of the second arched region is determined; the greater the minimum difference, the greater the degree of asymmetry between the first arched region and the second arched region about the target direction.

[0095] The greater the inclination of the line between the center of the straight line light spot 2 and the center of the effective area relative to the super lens 1 , the greater the eccentricity of the straight line light spot 2 .

[0096] It can be seen that by arranging the first arched area and the second arched area with arches facing each other in the effective area of ​​the superlens 1, the eccentricity of the line light spot 2 can be accurately controlled by controlling the symmetry between the first arched area and the second arched area.

[0097] It should be noted that there may be only one or more first arched regions in the effective region of the metalens 1; similarly, there may be only one or more second arched regions.

[0098] When there are multiple first arched areas in the effective area, the arch tops of the first arched areas are oriented in the same direction, and the first arched areas are adjacent to each other in a concentric manner. Figure 2 , Figure 3 or Figure 4 As shown, in this case, the shape formed by all the first arched regions together is similar to a multi-layered rainbow shape or a multi-layered Swiss roll shape.

[0099] Similarly, when there are multiple second arched areas in the effective area, the arch tops of the second arched areas face the same direction, and the second arched areas are adjacent to each other in a concentric manner. Figure 2 , Figure 3 or Figure 4As shown, in this case, the shape formed by all the second arched regions together is similar to a multi-layered rainbow shape or a multi-layered Swiss roll shape.

[0100] In order to design a metalens 1 for projecting a line light spot, it is necessary to first obtain the design requirement information, and then obtain the light intensity distribution requirements for the target line light beam from the design requirement information, that is, obtain the target light intensity distribution of the line light beam. Then, the shaping phase of the metalens 1 is designed with the target light intensity distribution as the output target, and finally the metalens 1 is designed based on the shaping phase, so that the metalens 1 can shape the line light beam to obtain the target requirement. Among them, the shaping phase is used to shape the incident light along the line length direction of the line light spot 2; the shaped line light beam can then be projected to obtain the line light spot 2.

[0101] The phase of the superlens 1 refers to the set of phases of all micro-nano structures 12 in the superlens 1. Therefore, determining the phase of the superlens 1 is to determine the phase of each micro-nano structure 12 in the superlens 1.

[0102] If the positions of each micro-nanostructure 12 in the metalens 1 are observed separately, the sub-beams modulated at the positions of each micro-nanostructure 12 need to be propagated to a specific spatial position with a specific light intensity distribution, so that all sub-beams with specific light intensity distribution at specific spatial positions together constitute a line beam with a target light intensity distribution. Therefore, if the phase of each micro-nanostructure 12 is to be accurately determined, it is necessary to match each micro-nanostructure 12 as accurately as possible with the sub-beam with a specific light intensity distribution at the specific spatial position to which it should be modulated. In order to accurately design the shaping phase, it is necessary to match each micro-nanostructure 12 as accurately as possible with the sub-beam with a specific light intensity distribution at the specific spatial position to which it should be modulated. Therefore, in the target light intensity distribution of the line beam, the number of light intensity data sampling points along the line length direction of the line spot 12 significantly affects the efficiency of the phase design.

[0103] In detail, in the target light intensity distribution of a line beam, the smaller the number of light intensity data sampling points along the line length direction, the coarser and sparser the local light intensity distribution that can be decomposed from the target light intensity distribution. The coarser and sparser these local light intensity distributions are, the more vague the matching relationship between the micro-nano structure 12 and the sub-beam of the specific light intensity distribution at the specific spatial position to be modulated in the initial stage of the shaping phase design is, so it is more difficult to design an accurate shaping phase, resulting in a lower phase design efficiency of the metalens 1.

[0104] In contrast, in the target light intensity distribution of a line beam, the greater the number of light intensity data sampling points along the length of the line, the finer and denser the local light intensity distribution that can be decomposed from the target light intensity distribution. The finer and denser these local light intensity distributions are, the more accurate the matching relationship between the micro-nano structure 12 and the sub-beam of the specific light intensity distribution at the specific spatial position to which it should be modulated in the initial stage of the shaping phase design is, so it is easier to design an accurate shaping phase, thereby making the phase design efficiency of the metalens 1 higher.

[0105] It should be noted that in the related art, the target light intensity distribution directly used for designing the phase is the target light intensity distribution obtained from the design requirement information. However, in many cases, the target light intensity distribution obtained from the design requirement information is usually represented by an image - either by hand-drawing, showing the light intensity curve corresponding to the target light intensity distribution along the length of the line in the image, or by using drawing software, showing the light intensity curve corresponding to the target light intensity distribution along the length of the line in the image.

[0106] Limited by the resolution of pixels in the image, the target light intensity distribution obtained from the design requirement information, including the number of light intensity data sampling points along the line length, is far from meeting the demand for efficient design of the shaping phase, which in turn leads to low phase design efficiency of the superlens in related technologies.

[0107] Therefore, in one embodiment, when designing a shaping phase for shaping the incident light along the line length direction, in the target light intensity distribution of a line light beam, the number of light intensity data sampling points along the line length direction is M. samp In the superlens 1, the maximum number of micro-nano structures 12 arranged along the one-dimensional direction is M nano . M samp =N*M nano , N is greater than or equal to 1; N can be an integer or a decimal.

[0108] The one-dimensional direction refers to any one-dimensional direction on the two-dimensional plane where the super lens 1 is located. Figure 5 FIG. 1 shows a schematic diagram of the arrangement of the micro-nano structures 12 in a horizontal one-dimensional direction in an embodiment of the present application. Figure 6 FIG. 1 is a schematic diagram showing a micro-nano structure 12 in an embodiment of the present application arranged along an inclined one-dimensional direction. Figure 5 and Figure 6In one embodiment, the micro-nano structures 12 on the metalens 1 can be arranged along a horizontal one-dimensional direction or along an inclined one-dimensional direction. When the micro-nano structures 12 are arranged along a horizontal one-dimensional direction, the metalens 1 can be divided into regions 10a, 10b, 10c, and 10d; when the micro-nano structures 12 are arranged along an inclined one-dimensional direction, the metalens 1 can be divided into regions 10e, 10f, 10g, and 10h. It can be seen from the figure that there is one micro-nano structure 12 arranged along the one-dimensional direction in region 10a, three micro-nano structures 12 arranged along the one-dimensional direction in region 10b, five micro-nano structures 12 arranged along the one-dimensional direction in region 10c, seven micro-nano structures 12 arranged along the one-dimensional direction in region 10d, four micro-nano structures 12 arranged along the one-dimensional direction in region 10e, three micro-nano structures 12 arranged along the one-dimensional direction in region 10f, four micro-nano structures 12 arranged along the one-dimensional direction in region 10g, and three micro-nano structures 12 arranged along the one-dimensional direction in region 10h. After traversing any one-dimensional direction, it can be seen Figure 5 and Figure 6 In the metalens 1 shown, the maximum number of micro-nano structures 12 arranged along the one-dimensional direction is 7. Figure 5 as well as Figure 6 In the corresponding embodiment, in the target light intensity distribution of a line light beam, the number of light intensity data sampling points along the line length direction is at least 7.

[0109] It should be noted that Figure 5 as well as Figure 6 It is only used to exemplarily show the distribution of the micro-nanostructure 12 on the metalens 1. Figure 5 as well as Figure 6 In the figure, the number and arrangement of the micro-nano structures 12 are exemplary and should not limit the protection scope of the present application.

[0110] In this embodiment, since M samp =N*M nano , N is greater than or equal to 1, so in the initial stage of the shaping phase design, on global average, each micro-nano structure 12 can match at least one unique light intensity data sampling point along the line length; therefore, in the target light intensity distribution of the line light beam, the number of light intensity data sampling points along the line length can effectively meet the demand for efficient design of the shaping phase, thereby improving the phase design efficiency of the metalens 1.

[0111] In the embodiment of the present application, the shaping phase can be designed by energy mapping. In the process of designing the shaping phase by energy mapping, it is necessary to integrate the light intensity based on the light intensity data sampled along the line length direction in the target light intensity distribution to determine the local light energy of each position corresponding to a single micro-nano structure 12 along the line length direction on the line light beam. In this case, in order to further improve the phase design efficiency, in one embodiment, M samp =N*M nano Where N is greater than or equal to 4.

[0112] That is, in this embodiment, at the initial stage of the shaping phase design, on global average, each micro-nano structure 12 can be matched with at least 4 unique light intensity data sampling points along the length of the line; therefore, when the shaping phase is designed by energy mapping, the local light energy at each position corresponding to a single micro-nano structure 12 is obtained by integrating the light intensity based on at least 4 sampled light intensity data, so that the integration result more accurately reflects the local light energy at each position corresponding to the single micro-nano structure 12, thereby further improving the phase design efficiency.

[0113] The present application provides a design method for a superlens 1 for projecting a line light spot 2. Figure 7 FIG. 1 is a flow chart showing a design method of a metalens 1 for projecting a line light spot 2 provided in the present application. Figure 7 , the method provided in this application includes:

[0114] Step S110, obtaining an initial target light intensity distribution of the line light beam from design requirement information used to describe the performance of the line light beam, wherein the line light beam is used to project the line light spot 2 onto the target plane 3;

[0115] Step S120, reconstructing the initial target light intensity distribution along the line length direction of the line light spot 2 to obtain a reconstructed target light intensity distribution, wherein along the line length direction, the resolution of the reconstructed target light intensity distribution is higher than the resolution of the initial target light intensity distribution;

[0116] Step S130, based on the reconstructed target light intensity distribution and the light intensity distribution of the incident light received by the metalens 1, a shaping phase for shaping the incident light along the line length direction is designed;

[0117] Step S140: Based on the shaping phase, determine the micro-nano structures 12 that should be arranged at various positions on the metalens 1, and design a metalens 1 for projecting a line light spot.

[0118] In the embodiment of the present application, the metalens 1 is used to shape the incident light into a line beam, and the line beam is then projected to obtain a line spot 2. The design requirement information used to describe the performance of the line beam at least describes the target light intensity distribution of the line beam. Therefore, the target light intensity distribution of the line beam is obtained from the design requirement information. In the embodiment of the present application, the target light intensity distribution obtained from the design requirement information is recorded as the initial target light intensity distribution.

[0119] As mentioned above, due to the limitation of the pixel resolution in the image, the target light intensity distribution obtained from the design requirement information, in which the number of light intensity data sampling points along the line length direction is far from meeting the requirements for efficient design of the shaping phase. That is, since the resolution of the initial target light intensity distribution is usually low, the initial target light intensity distribution is not suitable for direct use in the design phase.

[0120] To this end, in an embodiment of the present application, after obtaining the initial target light intensity distribution, the initial target light intensity distribution is reconstructed to obtain the reconstructed target light intensity distribution. The reconstruction process is mainly used to improve the resolution of the target light intensity distribution while maintaining the distribution characteristics of the target light intensity distribution unchanged, so that the resolution of the reconstructed target light intensity distribution is higher than the resolution of the initial target light intensity distribution. Specifically, the number of light intensity data sampling points along the line length direction provided by the reconstructed target light intensity distribution can be N times the maximum number of micro-nano structures 12 arranged along the one-dimensional direction in the superlens 1, and N is greater than or equal to 1.

[0121] It should be noted that, in general, the three-dimensional sensing, positioning identification and other applications are mainly realized based on the light intensity distribution of the line light beam along the line length direction, and there is generally no special requirement for the light intensity distribution along the line width direction. Therefore, the shaping accuracy of the light intensity distribution along the line width direction is not required to be high. Therefore, in the embodiment of the present application, at least the initial target light intensity distribution is reconstructed along the line length direction, so that at least along the line length direction, the resolution of the reconstructed target light intensity distribution is higher than the resolution of the initial target light intensity distribution. As for the line width direction, it is selectively reconstructed mainly depending on the application requirements.

[0122] After obtaining the reconstructed target light intensity distribution, the shaping phase for shaping the incident light along the line length direction is designed in combination with the light intensity distribution of the incident light received by the superlens 1.

[0123] The designed shaping phase is mainly used to modulate the intensity distribution of the incident light received by the metalens 1 along the line length direction, so that in the line length direction, the intensity distribution of the modulated light beam along the line length direction matches the reconstructed intensity distribution.

[0124] If, in addition to the light intensity distribution along the length of the line, the design requirements have other performance requirements for the line light beam, other phases can be designed according to the other performance requirements, and then the shaping phase is superimposed on the other phases to obtain the complete phase that the metalens 1 ultimately needs to provide. If the design requirements only have the performance requirements for the light intensity distribution along the length of the line for the line light beam, and the actual light beam incident angles at various locations on the metalens 1 have been considered when designing the shaping phase, the shaping phase directly constitutes the complete phase that the metalens 1 ultimately needs to provide.

[0125] Therefore, based on the shaping phase, the complete phase that the superlens 1 needs to provide in the end is obtained, and then the phase that needs to be provided at each position on the superlens 1 is determined. Then for each position on the superlens 1, the micro-nanostructure 12 that can provide the corresponding phase is screened out from the micro-nanostructure database, and the screened micro-nanostructure 12 needs to be arranged at the corresponding position; thereby determining the micro-nanostructure 12 that should be arranged at each position on the superlens, and thus designing the superlens 1 required for the target. The designed superlens 1 can shape the incident light into a straight line beam whose light intensity distribution along the line length direction meets the design requirements. Among them, the micro-nanostructure database refers to a database that describes at least the phase provided by the micro-nanostructure with various structural parameters for a light beam with a specific central wavelength.

[0126] As can be seen from the above, when the method provided by the present application is used to design a metalens 1 for projecting a line light spot, the target light intensity distribution directly used to design the phase is the reconstructed target light intensity distribution obtained by reconstructing the initial target light intensity distribution obtained from the design requirement information. Since the resolution of the reconstructed target light intensity distribution is higher than the resolution of the initial target light intensity distribution, the embodiment of the present application improves the phase design efficiency of the metalens 1.

[0127] In one embodiment, the initial target light intensity distribution is reconstructed along the line length direction of the light spot of the word line to obtain the reconstructed target light intensity distribution, including:

[0128] Extracting discrete light intensity data from the initial target light intensity distribution along the line length direction;

[0129] According to the discrete light intensity data, a light intensity distribution function is fitted to describe the initial target light intensity distribution along the line length direction;

[0130] The light intensity distribution function is discretized to obtain the reconstructed target light intensity distribution.

[0131] In this embodiment, the initial target light intensity distribution having conventional distribution characteristics along the line length direction is mainly reconstructed by using a fitting function.

[0132] Specifically, the initial target light intensity distribution with regular distribution characteristics along the length of the line refers to the initial target light intensity distribution with gentle or regular changes along the length of the line; this type of initial target light intensity is easy to accurately describe along the length of the line in the form of a function. For example: the initial target light intensity distribution is uniform along the length of the line; the initial target light intensity distribution is symmetrically concave along the length of the line; the initial target light intensity distribution is symmetrically convex along the length of the line, etc.

[0133] In this embodiment, after the initial target light intensity distribution is obtained from the design requirement information, the initial target light intensity distribution is sampled with a certain step length along the line length direction, so as to extract the discrete light intensity data in the initial target light intensity distribution. Preferably, the initial target light intensity distribution is sampled with a step length corresponding to the limiting resolution of the initial target light intensity distribution. For example: an image of the initial target light intensity distribution is obtained from the design requirement information; in this case, the step length corresponding to the limiting resolution of the initial target light intensity distribution is a single pixel period. Therefore, the image is sampled pixel by pixel with a single pixel period as a step length along the line length direction, so as to extract the discrete light intensity data in the initial target light intensity distribution.

[0134] Then, the discrete light intensity data extracted from the initial target light intensity distribution is fitted to obtain a light intensity distribution function describing the initial target light intensity distribution along the line length. Depending on the specific conventional distribution characteristics of the initial target light intensity distribution, the light intensity distribution function obtained by fitting can be a linear function, an exponential function, or a polynomial function.

[0135] It can be understood that the light intensity distribution function continuously describes the matching relationship between the coordinates along the length direction of the line and the light intensity distribution. Therefore, depending on the specific requirements for the resolution of the target light intensity distribution, the light intensity distribution function is discretized and valued according to the required arbitrary resolution. The discrete light intensity data obtained by discretizing the light intensity distribution function together constitute the reconstructed target light intensity distribution, thereby realizing the reconstruction of the initial target light intensity distribution.

[0136] In one embodiment, the initial target light intensity distribution is reconstructed along the line length direction of the light spot of the word line to obtain the reconstructed target light intensity distribution, including:

[0137] Extracting discrete light intensity data from the initial target light intensity distribution along the line length direction;

[0138] The discrete light intensity data is interpolated to obtain the reconstructed target light intensity distribution.

[0139] In this embodiment, the initial target light intensity distribution with special distribution characteristics along the length of the line is reconstructed by interpolation.

[0140] Specifically, the initial target light intensity distribution with special distribution characteristics along the line length refers to the initial target light intensity distribution that changes dramatically or irregularly along the line length; this type of initial target light intensity distribution is difficult to accurately describe along the line length in the form of a function.

[0141] In this embodiment, after obtaining the initial target light intensity distribution from the design requirement information, the initial target light intensity distribution is sampled at a certain step length along the line length direction, so as to extract the discrete light intensity data in the initial target light intensity distribution. Preferably, the initial target light intensity distribution is sampled at a step length corresponding to the limiting resolution of the initial target light intensity distribution.

[0142] Then, the discrete light intensity data extracted from the initial target light intensity distribution is interpolated, thereby expanding the discrete light intensity data; the expanded discrete light intensity data together constitute the reconstructed target light intensity distribution, thereby realizing the reconstruction of the initial target light intensity distribution. Specifically, the interpolation process can be performed using Lagrange interpolation method, Newton interpolation method, spline interpolation method, etc.

[0143] In one embodiment, based on the reconstructed target light intensity distribution and the light intensity distribution of the incident light received by the metalens 1, a shaping phase for shaping the incident light along the line length direction is designed, including:

[0144] Based on the law of conservation of energy, the light intensity distribution of the incident light is mapped one-to-one with the reconstructed target light intensity distribution along the line length direction, and the light beam exit angle at each position along the line length direction on the metalens 1 is determined based on the mapping result;

[0145] The shaping phase is calculated based on the light beam exit angle at each position along the line length direction of the metalens 1 and the light beam incident angle at each position along the line length direction of the metalens 1.

[0146] In this embodiment, after obtaining the reconstructed target light intensity distribution, the shaping phase is designed by energy mapping.

[0147] Specifically, from the law of conservation of energy, it can be known that if the energy loss generated by the light beam during the propagation process is ignored, the total light energy of the incident light received by the superlens is equal to the total light energy of the line light beam modulated by the superlens 1; therefore, the total light energy corresponding to the light intensity distribution of the incident light is equal to the total light energy corresponding to the target light intensity distribution after reconstruction of the line light beam.

[0148] By dividing the light intensity distribution of the incident light along the line length direction, the local light intensity distribution at each position along the line length direction on the metalens 1 can be determined, and then the local light energy received at each position along the line length direction on the metalens 1 can be determined in an integral manner.

[0149] Similarly, by segmenting the reconstructed target light intensity distribution along the line length, the local light intensity distribution at each position along the line length of the line beam can be determined, and then the local light energy at each position along the line length of the line beam can be determined in an integral manner.

[0150] Then, based on the law of conservation of energy, the positions along the length of the line on the metalens 1 are sequentially mapped one by one with the positions along the length of the line on the line beam. The positions on the metalens 1 and the positions on the line beam that have a mapping relationship have the same local light energy.

[0151] After the mapping is completed, the propagation direction of the light beam at each position along the line length direction on the metalens 1 can be determined based on the mapping result, and then the light beam exit angle at each position along the line length direction on the metalens 1 can be determined.

[0152] At the same time, when the light source is known, and the relative position and relative distance between the light source and the metalens 1 are determined, the incident angle of the light beam at each position along the line length direction on the metalens 1 can naturally be determined. Alternatively, if the incident angle of the light beam at each position along the line length direction on the metalens 1 is difficult to determine accurately enough, a collimation phase for collimating the incident light along the line length direction can be designed in addition to the shaping phase; under the action of the collimation phase corresponding to the line length direction, for the shaping phase, the incident angle of the light beam at each position along the line length direction on the metalens can be regarded as 0.

[0153] Therefore, by combining the light beam exit angle at each position along the line length direction on the metalens 1 and the light beam incident angle at each position along the line length direction on the metalens 1, the generalized Snell's law is applied to calculate the shaping phase used to shape the incident light along the line length direction.

[0154] In one embodiment, based on the reconstructed target light intensity distribution and the light intensity distribution of the incident light received by the metalens 1, a shaping phase for shaping the incident light along the line length direction is designed, including:

[0155] Along the line length direction, the reconstructed target light intensity distribution is constructed as a target image used as the target output of the phase recovery algorithm;

[0156] Based on the light intensity distribution of the incident light along the line length and the target image, the phase recovery algorithm is applied to obtain the shaped phase.

[0157] In this embodiment, after obtaining the reconstructed target light intensity distribution, a phase recovery algorithm is used to design the shaping phase along the line length direction.

[0158] Specifically, the phase recovery algorithm uses the diffraction theory of light to perform diffraction calculations on the input light field to obtain the intensity distribution of the output light field, and then compares the intensity distribution of the calculated output light field with the intensity distribution of the target output light field, and then iterates based on the comparison results to obtain a phase that can make the intensity distribution of the calculated output light field sufficiently consistent with the intensity distribution of the target output light field. Commonly used phase recovery algorithms include the GS (Gerchberg-Saxton) algorithm and the YG (Yang-Gu) algorithm.

[0159] In this embodiment, after obtaining the reconstructed target light intensity distribution, the reconstructed target light intensity distribution is constructed as a target image along the line length direction. Then, the light intensity distribution of the incident light along the line length direction is used as the input of the phase recovery algorithm, and the target image is used as the target output of the phase recovery algorithm. Under the action of the phase recovery algorithm, the phase for modulating the light intensity distribution of the incident light along the line length direction into the reconstructed target light intensity distribution along the line length direction is obtained, that is, the shaping phase for shaping the incident light along the line length direction is obtained.

[0160] In one embodiment, the method provided by the present application further includes:

[0161] Based on the distance between the metalens 1 and the light source, a collimation phase is designed to collimate the incident light along the line length direction; the designed phase of the metalens 1 includes a shaping phase and a collimation phase corresponding to the line length direction.

[0162] In this embodiment, in order to make the straight-line light beam shaped by the superlens 1 have a higher edge steepness in the direction of the line length, thereby improving the light energy utilization rate of the straight-line light beam, in addition to the shaping phase designed to shape the incident light along the line length direction, a collimation phase designed to collimate the incident light along the line length direction is also designed.

[0163] In this way, the complete phase that the designed superlens 1 needs to provide in the end includes the shaping phase and the collimation phase corresponding to the line length direction.

[0164] In this embodiment, the collimation phase corresponding to the line length direction is mainly designed according to the distance between the superlens 1 and the light source.

[0165] Specifically, in this embodiment, the collimation phase corresponding to the line length direction can be calculated using any of the following formulas:

[0166]

[0167]

[0168] in, is the collimation phase corresponding to the line length direction; λ is the central wavelength of the incident light; x1 is the projection length of the distance between each position on the superlens 1 and the center position of the superlens 1 in the line length direction; d1 is the distance between the superlens 1 and the light source.

[0169] In another embodiment, the collimation phase corresponding to the line length direction is calculated using the binary surface phase formula shown below:

[0170]

[0171] in, is the collimation phase corresponding to the line length direction; A i are the binary surface coefficients to be optimized; N is the number of binary surface coefficients. According to the optimized binary surface coefficients, the collimation phase corresponding to the corresponding line length direction is obtained, and then the incident light is simulated in the simulation software to continue to diffract and propagate after being modulated by the collimation phase corresponding to the line length direction, so as to verify the actual collimation effect of the collimation phase corresponding to the line length direction. If the actual collimation effect of the collimation phase corresponding to the line length direction does not meet expectations, the binary surface coefficients are optimized again, and the simulation verification is performed again until the actual collimation effect of the collimation phase corresponding to the line length direction meets expectations.

[0172] In one embodiment, the method provided by the present application further includes:

[0173] Obtain the target line width of the line spot 2 from the design requirement information;

[0174] Based on the target line width and the intensity distribution of the incident light, a line width compression phase is designed to compress the line width of the line spot 2 along the line width direction; the designed phase of the superlens 1 includes a shaping phase and a line width compression phase.

[0175] The narrower the line width of the line spot 2, the more concentrated its light energy is, and the more conducive it is to three-dimensional sensing or positioning identification. Therefore, in this embodiment, if there is a specific requirement for the performance of the metalens 1 in terms of the line width of the line spot 2, in addition to the shaping phase designed to shape the incident light along the line length direction, a line width compression phase for compressing the line width of the line spot 2 along the line width direction will also be designed.

[0176] Specifically, the target line width of the line spot 2 is obtained from the design requirement information. The target line width of the line spot 2 usually describes the upper limit of the line width of the line spot 2 at a specific working distance; the working distance refers to the distance between the metalens 1 and the target plane 3 used to project the line spot 2.

[0177] After determining the target line width of the line spot 2, the line width compression phase is designed based on the target line width and the intensity distribution of the incident light. Under the effect of the line width compression phase, the line width of the line spot 2 can meet the target line width requirement.

[0178] In this way, the phase that the designed superlens 1 ultimately needs to provide includes a shaping phase and a linewidth compression phase.

[0179] In one embodiment, the line width compression phase is a collimation phase along the line width direction, or a focusing phase along the line width direction.

[0180] Specifically, in this embodiment, the line width compression phase can be calculated using any formula shown below:

[0181]

[0182]

[0183] in, is the line width compression phase; λ is the central wavelength of the incident light; y1 is the projection length of the distance between each position on the superlens 1 and the center position of the superlens 1 in the line width direction; f1 is the focal length of the superlens 1.

[0184] When the line width compression phase is a collimation phase along the line width direction, f1 is equal to the distance between the super lens 1 and the light source; when the line width compression phase is a focusing phase along the line width direction, f1 is less than the distance between the super lens 1 and the light source.

[0185] Compared with the collimation phase along the line width direction, the focusing phase along the line width direction has a stronger ability to compress the line width; that is, compared with the narrowest line width that can be compressed by the collimation phase along the line width direction, the narrowest line width that can be compressed by the focusing phase along the line width direction is smaller.

[0186] However, compared with the working distance interval length of the narrowest line width adaptation that can be compressed by the collimation phase along the line width direction, the working distance interval length of the narrowest line width adaptation that can be compressed by the focusing phase along the line width direction is also smaller. Therefore, compared with the collimation phase along the line width direction, the focusing phase along the line width direction has stricter requirements on the working distance and is slightly less applicable.

[0187] Therefore, whether to use the collimation phase along the line width direction as the line width compression phase or to use the focusing phase along the line width direction as the line width compression phase requires comprehensive consideration of the requirements for the narrowest line width and the requirements for the working distance.

[0188] In another embodiment, the line width compression phase is calculated using the binary phase formula shown below:

[0189]

[0190] in, is the line width compression phase; A i are the binary surface coefficients to be optimized; N is the number of binary surface coefficients. According to the optimized binary surface coefficients, the corresponding line width compression phase is obtained, and then the result of the incident light continuing to diffract and propagate after the line width compression phase modulation is simulated in the simulation software, so as to verify the actual line width compression effect of the line width compression phase. If the actual line width compression effect of the line width compression phase does not meet expectations, the binary surface coefficients are optimized again and the simulation verification is performed again until the actual line width compression effect of the line width compression phase meets expectations.

[0191] The present application also provides an emission system for projecting a line of light spots 2 . Figure 8 The schematic diagram of the structure of the emission system for projecting a line of light spots provided by the present application is shown. Figure 8 The linear light beam emission system provided in the present application includes: a light source 5; and a super lens 1.

[0192] The super lens 1 is arranged on the light-emitting side of the light source 5, so that after the light beam emitted by the light source 5 propagates to the super lens 1, it is modulated into a line light beam by the super lens 1. After the line light beam is emitted from the super lens 1, it continues to propagate, and after propagating to the target plane 3, a line light spot 2 is projected on the target plane 3. Among them, the x-axis represents the line length direction of the line light spot 2, the y-axis represents the line width direction of the line light spot 2, and the z-axis represents the direction perpendicular to the super lens 1.

[0193] With reference to the description of any of the above embodiments, the detailed structural details of the metalens 1 are not repeated here.

[0194] Example 1

[0195] In the line beam emission system of Example 1, the light source is an EEL (Edge-Emitting Laser). The central wavelength of the light beam emitted by the light source is 650nm, the total divergence angle along the line length direction is 11.2°, the total divergence angle along the line width direction is 28.9°, and the size of the effective light emitting area along the line length direction is 180μm.

[0196] For the target required straight-line light beam, it is required to generate a straight-line light spot with a line width less than 2mm within the working distance range of 200mm to 2000mm; the light intensity distribution of the generated straight-line light spot along the line length is symmetrical and concave, the peak-to-valley ratio of the light intensity along the line length is 1:0.76, and the divergence angle between the double peaks of the light intensity in the line length direction is 150°.

[0197] Fig. 9The figure shows a line light spot projected by a line light beam emitted by the line light beam emitting system of Example 1. Fig.10 Shows Fig. 9 The light intensity distribution curve of the line spot in the line width direction is shown. Fig.11 Shows Fig. 9 The light intensity distribution curve of the line spot in the line length direction is shown.

[0198] At a working distance of 1500mm, the projection is Fig. 9 The line light spot shown in the figure. Fig.10 It can be seen that the peak light intensity As the line width boundary, the line width of the single-line spot is 1.8mm, which meets the line width requirement of less than 2mm. Fig.11 It can be seen that along the length of the line, the light spot has a light intensity peak-to-valley ratio of 1:0.76 within the divergence angle range of -75° to 75°, which meets the requirements of the peak-to-valley ratio and the divergence angle.

[0199] Example 2

[0200] In the line beam emission system of Example 2, the light source is EEL. The central wavelength of the light beam emitted by the light source is 450nm, the total divergence angle along the line length direction is 7.1°, and the total divergence angle along the line width direction is 31.5°. The effective light emitting area is composed of 15 light sources in three rows of 5 light sources in each row, and the arrangement direction of the 5 light sources in each row is parallel to the line length direction. The size of each light source along the line length direction is 320μm, the spacing along the line length direction is 150μm, and the spacing along the line width direction is 15μm.

[0201] For the target required straight line light beam, it is required to generate a straight line light spot with a line width less than 1.9mm within the working distance range of 400mm to 1000mm; the light intensity distribution of the generated straight line light spot along the length of the line is uniform but eccentric, and the divergence angle range of the uniform area is -15° to 75°; the standard for judging whether it is uniform or not is: if the light intensity unevenness is less than 8%, it means that the light intensity is uniform.

[0202] Fig.12 The diagram shows a line of light spot projected by a line of light beam emitted by the line of light beam emitting system of Example 2. Fig.13 Shows Fig.12 The light intensity distribution curve of the line spot in the line width direction is shown. Fig.14 Shows Fig.12 The light intensity distribution curve of the line spot in the line length direction is shown.

[0203] At a working distance of 1000mm, the projection is Fig.12 The line light spot shown in the figure. Fig.13 It can be seen that the peak light intensity As the line width boundary, the line width of the single-line spot is 1.87mm, which meets the line width requirement of less than 1.9mm. Fig.14 It can be seen that along the length of the line, the light spot has a light intensity non-uniformity of 3.9% within the divergence angle range of -15° to 75°, which meets the requirements of uniformity, eccentricity and divergence angle.

[0204] Example 3

[0205] In the line beam emission system of Example 3, the light source is EEL. The central wavelength of the light beam emitted by the light source is 950nm, the total divergence angle along the line length direction is 8.6°, the total divergence angle along the line width direction is 36.1°, and the size of the effective light emitting area along the line length direction is 60μm.

[0206] For the target required straight line light beam, it is required to generate a straight line light spot with a line width less than 0.8mm within the working distance range of 100mm to 300mm; the light intensity distribution of the generated straight line light spot along the length of the line is uniform, and the divergence angle of the uniform area is 90°; the standard for judging whether it is uniform or not is: if the light intensity unevenness is less than 3%, it means that the light intensity is uniform.

[0207] Fig.15 The diagram shows a line of light spot projected by a line of light beam emitted by the line of light beam emitting system of Example 3. Fig.16 Shows Fig.12 The light intensity distribution curve of the line spot in the line width direction is shown. Fig.17 Shows Fig.12 The light intensity distribution curve of the line spot in the line length direction is shown.

[0208] At a working distance of 200mm, the projection is Fig.15 The line light spot shown in the figure. Fig.16 It can be seen that the peak light intensity As the line width boundary, the line width of the single-line spot is 0.59mm, which meets the line width requirement of less than 0.8mm. Fig.17 It can be seen that along the length of the line, the light intensity non-uniformity of the line spot is 1.52% within the divergence angle range of -45° to 45°, which meets the requirements of uniformity and divergence angle.

[0209] Example 4

[0210] In the linear light beam emission system of Example 4, the light source is a VCSEL (Vertical-Cavity Surface-Emitting Laser). The central wavelength of the light beam emitted by the light source is 940nm, the total divergence angle is 29°, the size of the effective light emitting area is 20μm*280μm, and the effective light emitting area is composed of 8 light sources arranged along the length of the line.

[0211] Fig.18 The light intensity distribution that the straight line light beam of Example 4 should meet along the length direction is shown. For the straight line light beam required by the target, it is required to generate a straight line light spot with a line width less than 2.5mm at a working distance of 400mm; the generated straight line light spot should meet along the length direction Fig.15 The special light intensity distribution shown.

[0212] Fig.19 The figure shows a line light spot projected by a line light beam emitted by the line light beam emitting system of the fourth embodiment. Fig. 20 Shows Fig.19 The light intensity distribution curve of the line spot in the line width direction is shown. Fig.21 Shows Fig.19 The light intensity distribution curve of the line spot in the line length direction is shown.

[0213] At a working distance of 400mm, the projection is Fig.19 The line light spot shown in the figure. Fig. 20 It can be seen that the peak light intensity As the line width boundary, the line width of the single-line spot is 2.1mm, which meets the line width requirement of less than 2.5mm. Fig.21 It can be seen that along the length of the line, the light intensity distribution of the line spot satisfies Fig.15 Special requirements as indicated.

[0214] The present application also provides a design device for a superlens for projecting a line of light spots. Fig. 22 Schematic diagram of the design device of the metalens provided in this application. Fig. 22 , the design device of the metalens provided in this application includes:

[0215] The initial target light intensity distribution acquisition module 610 is configured to acquire the initial target light intensity distribution of the line light beam from the design requirement information used to describe the performance of the line light beam, wherein the line light beam is used to project the line light spot on the target plane;

[0216] The light intensity distribution reconstruction module 620 is configured to reconstruct the initial target light intensity distribution along the line length direction of the line light spot to obtain a reconstructed target light intensity distribution, wherein along the line length direction, the resolution of the reconstructed target light intensity distribution is higher than the resolution of the initial target light intensity distribution;

[0217] A shaping phase design module 630 is configured to design a shaping phase for shaping the incident light along the line length direction based on the reconstructed target light intensity distribution and the light intensity distribution of the incident light received by the metalens;

[0218] The micro-nano structure determination module 640 is configured to determine the micro-nano structures that should be arranged at various positions on the metalens based on the shaping phase, and to design a metalens for projecting a straight line light spot.

[0219] In an exemplary embodiment of the present application, the light intensity distribution reconstruction module 620 is configured as follows:

[0220] Extracting discrete light intensity data from the initial target light intensity distribution along the line length direction;

[0221] According to the discrete light intensity data, a light intensity distribution function is fitted to describe the initial target light intensity distribution along the line length direction;

[0222] The light intensity distribution function is discretized to obtain the reconstructed target light intensity distribution.

[0223] In an exemplary embodiment of the present application, the light intensity distribution reconstruction module 620 is configured as follows:

[0224] Extracting discrete light intensity data from the initial target light intensity distribution along the line length direction;

[0225] The discrete light intensity data is interpolated to obtain the reconstructed target light intensity distribution.

[0226] In an exemplary embodiment of the present application, the shaping phase design module 630 is configured as follows:

[0227] Based on the law of conservation of energy, the light intensity distribution of the incident light is mapped one-to-one with the reconstructed target light intensity distribution along the line length direction, and the light beam exit angle at each position along the line length direction on the metalens is determined based on the mapping result;

[0228] The shaping phase is calculated based on the light beam exit angle at each position along the line length direction of the metalens and the light beam incident angle at each position along the line length direction of the metalens.

[0229] In an exemplary embodiment of the present application, the shaping phase design module 630 is configured as follows:

[0230] Along the line length direction, the reconstructed target light intensity distribution is constructed as a target image used as the target output of the phase recovery algorithm;

[0231] Based on the light intensity distribution of the incident light along the line length and the target image, the phase recovery algorithm is applied to obtain the shaped phase.

[0232] In an exemplary embodiment of the present application, the design device is configured as follows:

[0233] Based on the distance between the metalens and the light source, a collimation phase is designed to collimate the incident light along the line length direction; the phase of the designed metalens includes a shaping phase and a collimation phase corresponding to the line length direction.

[0234] In an exemplary embodiment of the present application, the design device is configured as follows:

[0235] Obtain the target line width of the line spot from the design requirement information;

[0236] Based on the target line width and the intensity distribution of the incident light, a line width compression phase is designed to compress the line width of a line spot along the line width direction; the phase of the designed superlens includes a shaping phase and a line width compression phase.

[0237] In an exemplary embodiment of the present application, the line width compression phase is a collimation phase along the line width direction, or a focusing phase along the line width direction.

[0238] The present application also provides an electronic device. The electronic device is in the form of a general-purpose computing device. The components of the electronic device may include, but are not limited to: at least one processor, at least one memory, and a bus connecting different system components (including the memory and the processor). The processor may include: Fig. 22 The various modules in the device shown.

[0239] The memory stores program codes, which can be executed by the processor so that the processor executes the steps of the exemplary embodiments described in the various exemplary embodiments above. For example, the processor can execute Figure 7 The steps shown in .

[0240] The memory may include readable media in the form of volatile memory, such as random access memory (RAM) and / or cache memory, and may further include read only memory (ROM).

[0241] The memory may also include a program / utility having a set (at least one) of program modules, such program modules including but not limited to: an operating system, one or more application programs, other program modules and program data, each of which or some combination may include an implementation of a network environment.

[0242] The bus may represent one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processor, or a local bus using any of a variety of bus architectures.

[0243] The present application also provides a computer-readable storage medium having computer-readable instructions stored thereon. When the computer-readable instructions are executed by a processor of a computer, the computer is caused to execute a method provided by any of the above method embodiments.

[0244] 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. A super lens for projecting a line of light, characterized in that: The superlens includes a substrate and a micro-nano structure arranged on the substrate; the superlens is used to shape the incident light into a line beam, and the line beam is used to project the line light spot on the target plane; The divergence angle of the incident light parallel to the line length direction of the word line light spot is less than or equal to the divergence angle of the incident light parallel to the line width direction of the word line light spot.

2. The metalens according to claim 1, characterized in that The active area of ​​the metalens includes at least one first arched area and at least one second arched area; The top of the first arched area faces the second arched area, and the top of the second arched area faces the first arched area.

3. The metalens according to claim 2, characterized in that The first arched area and the second arched area are symmetrically distributed with respect to a target direction in a two-dimensional plane where the super lens is located, so that a line between a center of the line light spot and a center of the effective area is perpendicular to the super lens; The target direction is perpendicular to the dome orientation of the dome region.

4. The metalens according to claim 2, characterized in that The first arched area and the second arched area are asymmetrically distributed with respect to a target direction in a two-dimensional plane where the super lens is located, so that a line between a center of the line light spot and a center of the effective area is inclined to the super lens; The target direction is perpendicular to the dome orientation of the dome region.

5. The metalens according to claim 2, characterized in that When the effective area includes at least two first areas, the tops of the first arched areas are oriented in the same direction, and the first arched areas are adjacent to each other in a concentric manner; When the effective area includes at least two second areas, the arch tops of the second arch areas are oriented in the same direction, and the second arch areas are adjacent to each other in a concentric manner.

6. The metalens according to claim 1, characterized in that When a shaping phase is designed to shape the incident light along the line length direction of the one-line light spot, in the target light intensity distribution of the one-line light beam, the number of light intensity data sampling points along the line length direction is N times the maximum number of micro-nano structures arranged along the one-dimensional direction in the superlens, and N is greater than or equal to 1.

7. The superlens according to claim 6, characterized in that N is greater than or equal to 4.

8. A method for designing a metalens for projecting a line of light, characterized in that: The method is used to design a metalens as claimed in any one of claims 1 to 7, and the method comprises: Acquiring an initial target light intensity distribution of the line-shaped light beam from design requirement information used to describe the performance of the line-shaped light beam, wherein the line-shaped light beam is used to project a line-shaped light spot on a target plane; Reconstructing the initial target light intensity distribution along the line length direction of the line light spot to obtain a reconstructed target light intensity distribution, wherein along the line length direction, the resolution of the reconstructed target light intensity distribution is higher than the resolution of the initial target light intensity distribution; Based on the reconstructed target light intensity distribution and the light intensity distribution of the incident light received by the metalens, a shaping phase for shaping the incident light along the line length direction is designed; Based on the shaping phase, the micro-nano structures that should be arranged at various positions on the superlens are determined, and the superlens for projecting the line light spot is designed.

9. The method according to claim 8, characterized in that The initial target light intensity distribution is reconstructed along the line length direction of the one-line light spot to obtain a reconstructed target light intensity distribution, including: Extracting discrete light intensity data from the initial target light intensity distribution along the line length direction; According to the discrete light intensity data, a light intensity distribution function is fitted to describe the initial target light intensity distribution along the line length direction; The light intensity distribution function is discretized and valued to obtain the reconstructed target light intensity distribution.

10. The method according to claim 8, characterized in that The initial target light intensity distribution is reconstructed along the line length direction of the one-line light spot to obtain a reconstructed target light intensity distribution, including: Extracting discrete light intensity data from the initial target light intensity distribution along the line length direction; The discrete light intensity data is interpolated to obtain the reconstructed target light intensity distribution.

11. An emission system for projecting a line of light spots, characterized in that: The emission system comprises: a light source; a superlens as described in any one of claims 1 to 7; The super lens is arranged on the light emitting side of the light source.

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