Superlens for dodging and dodging module comprising same

Abstract

The utility model provides a super lens for dodging and a dodging module comprising the same. The super lens provided by the utility model comprises a substrate and a micro-nano structure arranged on the substrate, an effective area of the micro-nano structure is arranged in the super lens and comprises layered areas which are stacked layer by layer from inside to outside. Each layered region comprises at least one sub-region, and the shape of each sub-region is regular; each sub-region is used as a sub-super-lens to independently provide a diffusion phase for incident light, and when the same layered region comprises at least two sub-regions, the sub-regions in the same layered region are randomly distributed, so that the super-lens modulates the incident light into a uniform light beam with uniformly distributed light intensity. According to the super lens for dodging, the discretization efficiency of the coverage area of the sub super lens can be effectively improved, the improvement of the phase design efficiency of the sub super lens is facilitated, and the improvement of the phase design efficiency of the whole super lens is further facilitated.

Description

Technical Field

[0001] The present application relates to the field of optics, and in particular to a metalens for light homogenization and a light homogenization module comprising the metalens. Background Art

[0002] In applications such as three-dimensional sensing and image display, it is often necessary to generate a uniform light beam with uniform light intensity distribution. However, the light intensity of the light beams emitted by various light sources widely used in the optical field is not uniformly distributed. For example, the light intensity of the light beam emitted by VCSEL (Vertical-Cavity Surface-Emitting Laser) is Gaussian distributed; the light intensity of the light beam emitted by LED (Light-Emitting Diode) is Lambertian distributed.

[0003] To this end, it is necessary to provide a light homogenizing device to receive the light beam emitted by the light source, and then modulate the light beam emitted by the light source into a light homogenizing beam with uniform light intensity distribution. In order to reduce the volume and weight of the light homogenizing device, the related art proposes a metalens for light homogenization. However, the metalens for light homogenization provided by the related art, the design of the sub-metalens, will result in a low discretization efficiency for the coverage range of the sub-metalens, which is not conducive to improving the efficiency of the sub-metalens phase design, and thus is not conducive to improving the efficiency of the entire metalens phase design. Utility Model Content

[0004] One purpose of the present application is to propose a metalens for light homogenization and a light homogenization module containing the metalens. The metalens for light homogenization provided in the present application can effectively improve the discretization efficiency of the coverage range of the sub-metalens therein, which is conducive to improving the efficiency of the sub-metalens phase design, and further to improving the efficiency of the entire metalens phase design.

[0005] According to one aspect of an embodiment of the present application, a metalens for light homogenization is disclosed, the metalens comprising a substrate and a micro-nano structure provided on the substrate; an effective area of ​​the micro-nano structure is provided in the metalens, comprising layered areas stacked layer by layer from the inside to the outside; each layered area comprises at least one sub-area, and each sub-area has a regular shape;

[0006] Each sub-region acts as a sub-super-lens to independently provide a diffusion phase for the incident light, and when the same layered region includes at least two sub-regions, the sub-regions in the same layered region are randomly distributed so that the super-lens modulates the incident light into a uniform light beam with uniform light intensity distribution.

[0007] In an exemplary embodiment of the present application, when the same layered region includes at least two sub-regions, the sub-regions in the same layered region are randomly distributed in at least two sizes.

[0008] In an exemplary embodiment of the present application, when the same layered region includes at least two sub-regions, the sub-regions in the same layered region are randomly distributed in at least two regular shapes.

[0009] In an exemplary embodiment of the present application, in the metalens, the size deviation between different sub-regions is less than or equal to a preset size threshold.

[0010] In an exemplary embodiment of the present application, in the metalens, the diffusion phases provided by each sub-metalens respectively correspond to illumination coverage angles randomly distributed in the same direction.

[0011] In an exemplary embodiment of the present application, in the metalens, the angular deviation between the illumination coverage angles corresponding to the diffusion phases provided by different sub-metalens in the same direction is less than or equal to a preset angle threshold.

[0012] In an exemplary embodiment of the present application, all layered regions in at least one superimposed layer constitute an annular region.

[0013] In an exemplary embodiment of the present application, all vertices of each sub-region are located at the boundary of the layered region.

[0014] In an exemplary embodiment of the present application, the metalens is also used to provide a collimated phase for the incident light as a whole.

[0015] According to one aspect of an embodiment of the present application, a light homogenization module is disclosed, the light homogenization module comprising: a light source; a super lens as provided in any of the above embodiments;

[0016] The super lens is arranged on the light emitting side of the light source.

[0017] Since the metalens provided in the present application imposes random factors on the sub-metalens under the constraints of the layered region, the respective coverage ranges of different sub-metalens in the same layered region can be connected by means of the boundary of the layered region; and the shape of each sub-metalens is regular. Therefore, the metalens provided in the present application can effectively improve the discretization efficiency of the coverage range of the sub-metalens, which is beneficial to improving the efficiency of the sub-metalens phase design, and further to improving the efficiency of the entire metalens phase design.

[0018] 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.

[0019] 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

[0020] 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.

[0021] Figure 1 A schematic diagram of the effective area division of a metalens for light homogenization in an embodiment of the present application is shown.

[0022] Figure 2 Shows Figure 1 A magnified close-up of the local active area of ​​the metalens is shown.

[0023] Figure 3 A schematic diagram of the effective area division of a metalens for light homogenization in an embodiment of the present application is shown.

[0024] Figure 4 A schematic diagram of the effective area division of a metalens for light homogenization in an embodiment of the present application and an enlarged close-up of a local effective area are shown.

[0025] Figure 5 A schematic diagram of the effective area division of a metalens for light homogenization in an embodiment of the present application and an enlarged close-up of a local effective area are shown.

[0026] Figure 6 A schematic diagram of the effective area division of a metalens for light homogenization in an embodiment of the present application and an enlarged close-up of a local effective area are shown.

[0027] Figure 7 A schematic diagram of the effective area division of a metalens for light homogenization in an embodiment of the present application and an enlarged close-up of a local effective area are shown.

[0028] Figure 8 A schematic diagram of the effective area division of a metalens for light homogenization in an embodiment of the present application and an enlarged close-up of a local effective area are shown.

[0029] Fig. 9 The schematic diagram of the structure of the light homogenization module provided in the present application is shown.

[0030] Fig.10 A schematic diagram showing the diffusion phases provided by each sub-super-lens in the super-lens in the light homogenization module provided in Example 1 is shown.

[0031] Fig.11 A schematic diagram showing the complete phase provided by the superlens in the light homogenization module provided in Example 1 is shown.

[0032] Fig.12 A schematic diagram of the light intensity distribution of a light spot obtained by projecting a uniform light beam output by the uniform light module provided in Example 1 is shown.

[0033] Fig.13 A schematic diagram of the complete phase provided by the superlens in the light homogenization module provided in Example 2 is shown.

[0034] Fig.14 A schematic diagram of the light intensity distribution of a light spot obtained by projecting a uniform light beam output by the uniform light module provided in Example 2 is shown.

[0035] Fig.15 A schematic diagram of the complete phase provided by the superlens in the light homogenization module provided in Example 3 is shown.

[0036] Fig.16 A schematic diagram of the light intensity distribution of a light spot obtained by projecting a uniform light beam output by the uniform light module provided in Example 3 is shown.

[0037] Description of reference numerals:

[0038] 1-Superlens; 2-Light source. DETAILED DESCRIPTION

[0039] 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.

[0040] 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.

[0041] 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.

[0042] The metalens for light homogenization provided by the related art includes a plurality of sub-metalens. The related art adopts a method of applying random factors to the sub-metalens to improve the light homogenization effect of the light homogenization beam modulated and output by the metalens. Specifically, the related art mainly adopts the following two methods to apply random factors to the sub-metalens:

[0043] First, the positions and sizes of all sub-superlenses are initialized, and then random factors are applied to the positions and sizes of all sub-superlenses within the effective area of ​​the entire superlens. All initialized sub-superlenses are arranged at equal intervals and have the same size. After applying the random factors, the positions of all sub-superlenses are randomly distributed within the effective area of ​​the entire superlens, and the sizes of all sub-superlenses are randomly distributed within the effective area of ​​the entire superlens.

[0044] Second, after determining the position of each sub-superlens, a random polygon generation algorithm is used to generate the closed edge of each sub-superlens based on the position of each sub-superlens, thereby applying a random factor to the shape of all sub-superlenses. The shapes of most sub-superlenses generated in this way are irregular.

[0045] It should be noted that in order to design a superlens that can fully exert the beam modulation capability, it is necessary to determine the phase distribution of the superlens, that is, it is necessary to determine the phase of each position on the superlens. Similarly, for a sub-superlens, it is necessary to determine the phase of each position on the sub-superlens. It can be understood that if the phase of each position on the sub-superlens is to be determined, a necessary prerequisite is to accurately discretize the coverage of the sub-superlens, so as to accurately determine the discrete position information on the sub-superlens. Therefore, the discretization efficiency of the coverage of the sub-superlens directly affects the efficiency of the sub-superlens phase design. The higher the discretization efficiency of the coverage of the sub-superlens, the more conducive it is to improve the efficiency of the sub-superlens phase design.

[0046] Regarding the first method adopted by the related art, since this method applies random factors to the position and size of the sub-superlens within the effective area of ​​the entire superlens, the position and size of all sub-superlenses are highly free and random. In this case, the positions and sizes of different sub-superlenses have almost nothing in common, so the discretization process of the coverage range of different sub-superlenses is almost completely isolated from each other and has almost no connection. As a result, the discretization efficiency of the coverage range of the sub-superlens is low, which is not conducive to improving the efficiency of the sub-superlens phase design.

[0047] Regarding the second method used in the related art, since the shapes of most of the sub-superlenses generated in this way are irregular, and it is obviously difficult to discretize the irregular shape areas efficiently, the second method used in the related art will also result in low discretization efficiency for the coverage of the sub-superlens, which is also not conducive to improving the efficiency of the sub-superlens phase design.

[0048] In summary, it can be seen that the design of the sub-super-lens for the uniform light provided by the related technology will result in a low discretization efficiency for the coverage range of the sub-super-lens, which is not conducive to improving the efficiency of the sub-super-lens phase design, and further is not conducive to improving the efficiency of the entire super-lens phase design.

[0049] In order to overcome the above-mentioned defects of the related art, the present application provides a metalens for light homogenization. The metalens for light homogenization provided in the present application can effectively improve the discretization efficiency of the coverage range of the sub-metalens, which is conducive to improving the efficiency of the sub-metalens phase design, and further to improving the efficiency of the entire metalens phase design.

[0050] Figure 1 FIG. 1 shows a schematic diagram of the effective area division of a metalens for light homogenization in an embodiment of the present application. Figure 2 Shows Figure 1 A magnified close-up of the local effective area of ​​the metalens shown. The effective area of ​​the metalens refers to the area in the metalens where the light beam is effectively modulated by the micro-nanostructure.

[0051] See also Figure 1 and Figure 2 The metalens 1 for light homogenization provided in the present application includes a substrate and a micro-nano structure arranged on the substrate. The metalens 1 mainly provides a phase mutation to the received light beam through the micro-nano structure at various positions, so that a certain phase gradient is generated at various positions on the metalens 1, thereby exerting a certain modulation effect on the light beam received at various positions.

[0052] In the embodiment of the present application, the effective area of ​​the superlens 1 includes layered areas stacked from the inside to the outside. Each layered area includes at least one sub-area, and each sub-area has a regular shape.

[0053] by Figure 1 and Figure 2For example: Optionally, a layered region 11 is set at the center of the effective area of ​​the metalens 1; the layered region 11 includes only one sub-region 11a. The layered region 12L is superimposed on the left of the layered region 11, the layered region 12D is superimposed below, the layered region 12R is superimposed on the right, and the layered region 12U is superimposed above; the layered region 12L includes five sub-regions 12a, 12b, 12c, 12d and 12e, the layered region 12D includes three sub-regions 12f, 12g and 12h, the layered region 12R includes three sub-regions 12i, 12j and 12k, and the layered region 12U includes only one sub-region 12l. Similarly, the details of the division of other layered regions and sub-regions therein are not repeated. Figure 1 and Figure 2 In the metalens 1 shown, each sub-region is rectangular.

[0054] In the embodiment of the present application, each sub-region is used as a sub-super lens to independently divide the incident light, thereby providing a diffusion phase. Under the action of the diffusion phase, the light beam received by each sub-super lens is modulated and output as diffuse light. Since the sub-super lenses are closely connected to each other, the diffuse light output by adjacent sub-super lenses will mix with each other, so that the super lens 1 homogenizes the incident light.

[0055] However, if the sub-super-lenses in the super-lens 1 are distributed periodically, the diffused light output by adjacent sub-super-lenses will easily interfere with each other when mixed, which will lead to a decrease in the homogenization effect. To this end, in an embodiment of the present application, for the same layered region including at least two sub-regions, a random factor is applied to the sub-regions therein, so that the sub-regions therein are randomly distributed, and the corresponding sub-super-lenses are randomly distributed. In this way, the interference generated by the diffused light output by adjacent sub-super-lenses when mixed with each other is broken, thereby ensuring the homogenization effect, so that the super-lens 1 modulates the incident light into a uniform light beam with uniform light intensity distribution.

[0056] Since the metalens 1 provided in the present application applies random factors to the sub-metalens under the constraint of the layered region, the respective coverage ranges of different sub-metalens in the same layered region can be connected by means of the boundary of the layered region; and the shape of each sub-metalens is regular. Therefore, the metalens 1 provided in the present application can effectively improve the discretization efficiency of the coverage range of the sub-metalens, which is beneficial to improving the efficiency of the sub-metalens phase design, and further to improving the efficiency of the phase design of the entire metalens 1.

[0057] It should be noted that the regular shapes referred to in this application refer to geometric shapes that have specific recognized definitions and titles, including but not limited to: triangles; rectangles; parallelograms excluding rectangles; trapezoids; circles; sectors; and sector rings.

[0058] In one embodiment, when the same layered region includes at least two sub-regions, the sub-regions in the same layered region are randomly distributed in at least two sizes. That is, in this embodiment, for the same layered region including at least two sub-regions, a random factor is applied to the size of the sub-regions therein, so that the sizes of the sub-regions therein are randomly distributed.

[0059] The size of the sub-region may refer to the radius of the circumscribed circle corresponding to the sub-region, or may refer to the area of ​​the sub-region.

[0060] Specifically, Figure 1 and Figure 2 For example, the layered region 12L includes five sub-regions, each of which is rectangular, and the sizes of all sub-regions parallel to the horizontal direction are equal, but the sizes parallel to the vertical direction are randomly distributed. In this way, the sub-regions in the layered region 12L are randomly distributed in at least two sizes.

[0061] In one embodiment, when the same layered region includes at least two sub-regions, the sub-regions in the same layered region are randomly distributed in at least two regular shapes. That is, in this embodiment, for the same layered region including at least two sub-regions, random factors are applied to the selection and combination of the regular shapes of the sub-regions therein, so that the shapes of the sub-regions therein are randomly distributed; at the same time, the shape of each sub-region is regular.

[0062] Figure 3 FIG. 1 shows a schematic diagram of the effective area division of the metalens 1 for light homogenization in an embodiment of the present application. Figure 3 In one embodiment, the shapes of the sub-regions include: triangle; rectangle; parallelogram excluding rectangle; trapezoid. In this embodiment, by arranging a plurality of sub-regions of different regular shapes in the same layered region, the shapes of these sub-regions are randomly distributed.

[0063] It should be noted that if the size of some sub-super-lenses is too large, it is difficult for these sub-super-lenses to split the incident light finely enough; as a result, the diffuse light modulated and output by these sub-super-lenses is difficult to mix evenly, which will result in poor homogenization of the uniform light beam output by the super-lens 1.

[0064] It should also be noted that when the average size of the sub-super-lenses is smaller than a certain level, further reducing the average size of the sub-super-lenses will no longer significantly improve the homogenization effect of the uniform light beam output by the super-lens 1. However, the smaller the average size of the sub-super-lenses, the more sub-super-lenses there are, and the diffusion phase of each sub-super-lens needs to be designed independently; therefore, the smaller the average size of the sub-super-lenses, the greater the cost of the phase design of the super-lens 1.

[0065] Therefore, in one embodiment, regardless of whether a random factor is applied to the sizes of different sub-regions in the same layered region, the size deviations between different sub-regions in the metalens 1 are less than or equal to a preset size threshold. That is, in the metalens 1, the sizes of all sub-metalenses are within a size range centered on a certain specific size.

[0066] In this embodiment, by controlling the sizes of all sub-superlenses to be within a size range centered on a specific size, the uniform light beam output by the superlens 1 has an excellent uniformity effect, while avoiding excessive costs due to the phase design of the superlens 1.

[0067] In one embodiment, in the metalens 1, the diffusion phases provided by the sub-metalens respectively correspond to the illumination coverage angles FOI (Field Of Illumination) in the same direction and are randomly distributed.

[0068] Among them, the illumination coverage angle corresponding to the diffusion phase provided by the sub-superlens is the illumination coverage angle of the diffuse light modulated and output by the corresponding sub-superlens. If an observation screen parallel to the superlens 1 is set on the light-emitting side of the superlens 1, the diffuse light modulated and output by the sub-superlens will be projected on the observation screen to obtain a light spot with a specific coverage range. It is recorded that the optical axis of the diffuse light modulated and output by the sub-superlens passes through the position L1 on the superlens 1, and the projection position of the optical axis of the diffuse light modulated and output by the sub-superlens on the observation screen is position L2; in general, position L2 is the center position of the light spot obtained by projecting the diffuse light modulated and output by the sub-superlens. Along the target direction of the two-dimensional plane where the observation screen is located, the light spot is intercepted through position L2, and the intersection position of the intercept line and the edge of the light spot is recorded as L3. The line between position L1 and position L2 is denoted as L1-L2, and the line between position L1 and position L3 is denoted as L1-L3. The angle between line L1-L3 and line L1-L2 is the illumination coverage angle (half angle) of the diffuse light modulated and output by the sub-superlens in the target direction.

[0069] The illumination coverage angle can be used as an indicator to design the diffusion phase of the sub-super lens. Therefore, in this embodiment, a random factor can be applied to the illumination coverage angle in a specific direction during the phase design stage. After obtaining the randomized illumination coverage angle, the diffusion phase of the corresponding sub-super lens can be designed with the randomized illumination coverage angle as the target. The randomization of the illumination coverage angle is also conducive to breaking the interference caused by the diffusion light output by adjacent sub-super lenses when mixing with each other, thereby further improving the homogenization effect.

[0070] It should be noted that the consistency of the illumination coverage angles of the diffused light modulated and output by each sub-superlens significantly affects the continuity of the diffused light modulated and output by adjacent sub-superlenses when mixed with each other, and further significantly affects the uniformity of the uniform light beam modulated and output by the entire superlens 1. Therefore, the illumination coverage angles of each sub-superlens should be basically consistent with each other.

[0071] In detail, assuming that the light energy of the light beam received by each sub-super-lens is basically the same, and the illumination coverage angle of a certain sub-super-lens is significantly smaller than the illumination coverage angle of other sub-super-lenses, then compared with the diffuse light modulated by other sub-super-lenses, the diffuse light modulated by this sub-super-lens will be significantly concentrated, thereby causing the light intensity of the part corresponding to the position of this sub-super-lens in the uniform light beam modulated by the entire super-lens 1 to be significantly higher.

[0072] In contrast, assuming that the light energy of the light beam received by each sub-super-lens is basically the same, and the illumination coverage angle of a certain sub-super-lens is significantly larger than the illumination coverage angle of other sub-super-lenses, then compared with the diffuse light modulated by other sub-super-lenses, the diffuse light modulated by this sub-super-lens will be significantly dispersed, thereby causing the light intensity of the portion corresponding to the position of this sub-super-lens in the uniform light beam modulated by the entire super-lens 1 to be significantly lower.

[0073] Therefore, in one embodiment, regardless of whether a random factor is applied to the illumination coverage angle of each sub-metal lens, in metalens 1, the angular deviation between the illumination coverage angles corresponding to the diffusion phases provided by different sub-metal lenses in the same direction is less than or equal to a preset angle threshold. That is, in metalens 1, the illumination coverage angles of all sub-metal lenses are within an angle range centered on a certain illumination coverage angle.

[0074] In this embodiment, by controlling the illumination coverage angles of all sub-super-lenses to be within an angle range centered on a certain illumination coverage angle, the illumination coverage angles of the diffused light modulated and output by each sub-super-lens are highly consistent, thereby making the diffused light modulated and output by adjacent sub-super-lenses maintain a high degree of continuity when mixed with each other, and ultimately making the uniform light beam modulated and output by the entire super-lens 1 highly uniform.

[0075] In one embodiment, all layered regions in at least one stacking level constitute an annular region. The annular region includes: a square annular region; a circular annular region. In addition, the stacking level is used to describe the stacking order of the layered regions when they are stacked layer by layer in a single direction.

[0076] Specifically, the starting layered region stacked layer by layer is layered region 11, which is in the first stacking level. If each layered region is a rectangular region, the four layered regions 12L, 12D, 12R and 12U directly stacked on the left, bottom, right and top of layered region 11 are all in the second stacking level; the layered region 13L directly stacked on the left of 12L, the layered region 13D directly stacked below 12D, the layered region 13R directly stacked on the right of 12R and the layered region 13U directly stacked above 12U are all in the third stacking level. And so on.

[0077] In this embodiment, all layered regions of one superimposed layer constitute an annular region, or all layered regions of multiple superimposed layers constitute an annular region. It can be understood that the annular region can maintain a continuous coverage range within a 360-degree direction, so that all layered regions in the annular region can have a certain degree of randomness in at least two non-parallel directions, thereby effectively breaking the interference effect in the two-dimensional plane, thereby effectively improving the homogenization effect.

[0078] Figure 4 A schematic diagram of the effective area division of the metalens 1 for light homogenization in one embodiment of the present application and an enlarged close-up of a local effective area are shown. Figure 5 A schematic diagram of the effective area division of the metalens 1 for light homogenization in one embodiment of the present application and an enlarged close-up of a local effective area are shown. Figure 6 A schematic diagram of the effective area division of the metalens 1 for light homogenization in one embodiment of the present application and an enlarged close-up of a local effective area are shown.

[0079] Figure 4 In the illustrated embodiment, the layered region 11 at the first stacking level includes only one sub-region. The layered regions 12L, 12D, 12R and 12U at the second stacking level may together form an annular region.

[0080] Figure 5 In the illustrated embodiment, the layered region 11 at the first stacking level includes three sub-regions. The layered regions 12L, 12D, 12R and 12U at the second stacking level may together form an annular region.

[0081] Figure 6In the illustrated embodiment, the layered region 11 at the first superposition level includes only one sub-region. The layered regions 12L, 12D, 12R and 12U at the second superposition level cannot together form an annular region, and the layered regions 13L, 13D, 13R and 13U at the third superposition level cannot together form an annular region. However, all the layered regions 12L, 12D, 12R, 12U, 13L, 13D, 13R and 13U in the second superposition level and the third superposition level can together form an annular region.

[0082] In the embodiment of the present application, the layered region in the effective region of the metalens 1 can be as follows Figure 1 It is shown as a rectangle, but it can also be a circle, a sector ring, a circular ring, etc. When the layered regions constituting the annular region are all rectangular, the annular region is a square ring; when the layered regions constituting the annular region include a sector ring and a circular ring, the annular region is a circular ring.

[0083] Figure 7 A schematic diagram of the effective area division of the metalens 1 for light homogenization in one embodiment of the present application and an enlarged close-up of a local effective area are shown. Figure 8 A schematic diagram of the effective area division of the metalens 1 for light homogenization in one embodiment of the present application and an enlarged close-up of a local effective area are shown.

[0084] See also Figure 7 and Figure 8 In one embodiment, all vertices of each sub-region are located at the boundary of the layered region. Figure 7 In , each sub-region is a rectangle. The four vertices of each sub-region are located at the boundary of the layered region. Figure 8 In the example, the shapes of the sub-regions include triangles, rectangles, parallelograms excluding rectangles, and trapezoids; however, no matter what the specific shapes of the sub-regions are, all of their vertices are located at the boundaries of the layered region.

[0085] In this embodiment, since all vertices of each sub-region are located at the boundary of the layered region, all vertices of each sub-region can be quickly determined by means of the boundary of the layered region. Since the shape of each sub-region is regular, after all vertices of each sub-region are determined, the coverage of the sub-metalens corresponding to each sub-region can be quickly discretized, which is further beneficial to improve the efficiency of the phase design of the entire metalens 1.

[0086] It should be noted that, according to application requirements, in other embodiments, at least one vertex of at least one sub-region may be arranged outside the boundary of the layered region. Compared with the design of "all vertices of each sub-region are located at the boundary of the layered region", the design of "at least one vertex of at least one sub-region is located outside the boundary of the layered region" may slightly reduce the efficiency of the entire metalens 1 phase design, but it may allow the distribution of the sub-regions to have a stronger randomness, thereby further improving the homogenization effect.

[0087] It should also be noted that the design of "at least one vertex of at least one sub-region is located outside the boundary of the layered region" will slightly reduce the efficiency of the entire metalens 1 phase design, compared with the design of "all vertices of each sub-region are located at the boundary of the layered region". Compared with the related art, the design of "at least one vertex of at least one sub-region is located outside the boundary of the layered region" can also effectively improve the efficiency of the entire metalens 1 phase design.

[0088] It should also be noted that when the sub-region is circular or fan-shaped, any point on its arc edge can be used as the vertex of the sub-region. When the sub-region is fan-shaped, any point on its arc edge and its corresponding center point can be used as the vertex of the sub-region.

[0089] In one embodiment, the metalens 1 is also used as a whole to provide a collimated phase for the incident light, so as to improve the edge steepness of the output uniform light beam, so that the edge of the light spot obtained by projecting the uniform light beam is sharper and clearer.

[0090] Specifically, the collimation phase can be described by the following formula:

[0091]

[0092] in, is the collimation phase, x and y are the Cartesian coordinates of each position on the metalens 1 relative to the center position of the metalens 1, λ is the central wavelength of the incident light, f is the focal length of the metalens 1, and n is the adjustment factor, which is greater than or equal to 1. When n is equal to 1, the edge steepness of the uniform light beam output by the metalens 1 is the highest; the larger n is, the lower the edge steepness of the uniform light beam output by the metalens 1 is.

[0093] The present application also provides a light homogenization module. Fig. 9 The structure diagram of the light homogenization module provided in this application is shown. Fig. 9 The light homogenization module provided in the present application includes: a light source 2; and a superlens 1 as provided in any of the above embodiments.

[0094] The light source 2 may be a single point light source or an array light source. The specific type of the light source 2 may be VCSEL, LED, EEL (Edge-Emitting Laser), etc.

[0095] The metalens 1 is disposed on the light-emitting side of the light source 2. In this way, the light beam emitted by the light source 2 is the incident light of the metalens 1, and then the metalens 1 modulates the light beam emitted by the light source 2 into a uniform light beam. Referring to the design provided for the metalens 1 in any of the above embodiments, the design details of the metalens 1 will not be repeated here.

[0096] Example 1

[0097] Fig.10 A schematic diagram showing the diffusion phases provided by each sub-superlens in the superlens 1 in the light homogenization module provided in Example 1 is shown. Fig.11 A schematic diagram showing the complete phase provided by the superlens 1 in the light homogenization module provided in Example 1 is shown. Fig.12 A schematic diagram of the light intensity distribution of a light spot obtained by projecting a uniform light beam output by the uniform light module provided in Example 1 is shown.

[0098] The light source 2 in the light homogenization module provided in Example 1 is a 16*14 array light source; each sub-light source is a VCSEL with an emission angle of 20° and a central wavelength of 850 nm.

[0099] See also Fig.10 The metalens 1 in the light homogenizing module provided in Example 1 has a maximum stacking level of 7 in the effective area of ​​the layered region; each sub-region in the layered region acts as a sub-metalens to independently provide a diffusion phase for the incident light.

[0100] See also Fig.11 In Example 1, the phase provided by the superlens 1 includes not only the diffusion phase provided by each sub-superlens, but also the collimation phase provided by the superlens 1 as a whole. That is, the complete phase provided by the superlens is the phase obtained by superimposing the diffusion phase and the collimation phase.

[0101] See also Fig.12 The uniform light module provided in Example 1 has an illumination coverage angle (full angle) of 39°*39° output by the uniform light beam.

[0102] Example 2

[0103] Fig.13 A schematic diagram showing the complete phase provided by the superlens 1 in the light homogenization module provided in Example 2 is shown. Fig.14 A schematic diagram of the light intensity distribution of a light spot obtained by projecting a uniform light beam output by the uniform light module provided in Example 2 is shown.

[0104] The light source 2 in the light homogenization module provided in Example 2 is a 26*22 array light source; each sub-light source is a VCSEL with an emission angle of 20° and a central wavelength of 940 nm.

[0105] See also Fig.13 In the light homogenization module provided in Example 2, the maximum stacking level of the layered regions in the effective area of ​​the metalens 1 is 9; each sub-region in the layered region serves as a sub-metalens to independently provide a diffusion phase for the incident light. In addition, in Example 2, the metalens 1 only provides a diffusion phase and does not include a collimation phase.

[0106] See also Fig.14 The uniform light module provided in Example 1 has an illumination coverage angle (full angle) of 90°*70° for the uniform light beam outputted therefrom.

[0107] Example 3

[0108] Fig.15 A schematic diagram showing the complete phase provided by the superlens 1 in the light homogenization module provided in Example 3 is shown. Fig.16 A schematic diagram of the light intensity distribution of a light spot obtained by projecting a uniform light beam output by the uniform light module provided in Example 3 is shown.

[0109] The light source 2 in the light homogenization module provided in Example 3 is a 26*22 array light source; each sub-light source is a VCSEL with an emission angle of 20° and a central wavelength of 940 nm.

[0110] See also Fig.15 In the light homogenization module provided in Example 3, the maximum stacking level of the layered region in the effective area of ​​the metalens 1 is 26; each sub-region in the layered region serves as a sub-metalens to independently provide a diffusion phase for the incident light. In addition, in Example 3, the metalens 1 only provides a diffusion phase and does not include a collimation phase.

[0111] See also Fig.16 The uniform light module provided in Example 3 has an illumination coverage angle (full angle) of 120°*90° for the uniform light beam outputted therefrom.

[0112] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the utility model 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 metalens for light homogenization, characterized in that: The superlens includes a substrate and a micro-nano structure disposed on the substrate; the effective area of ​​the micro-nano structure disposed in the superlens includes layered areas stacked layer by layer from the inside to the outside; each layered area includes at least one sub-area, and each sub-area has a regular shape; Each sub-region acts as a sub-super-lens to independently provide a diffusion phase for the incident light, and when the same layered region includes at least two sub-regions, the sub-regions in the same layered region are randomly distributed so that the super-lens modulates the incident light into a uniform light beam with uniform light intensity distribution.

2. The metalens according to claim 1, characterized in that When the same layered region includes at least two sub-regions, the sub-regions in the same layered region are randomly distributed in at least two sizes.

3. The metalens according to claim 1, characterized in that When the same layered region includes at least two sub-regions, the sub-regions in the same layered region are randomly distributed in at least two regular shapes.

4. The metalens according to claim 1, wherein: In the metalens, the size deviation between different sub-regions is less than or equal to a preset size threshold.

5. The metalens according to claim 1, wherein: In the superlens, the diffusion phases provided by the sub-superlenses respectively correspond to randomly distributed illumination coverage angles in the same direction.

6. The metalens according to claim 1, characterized in that In the metalens, the angular deviation between the illumination coverage angles corresponding to the diffusion phases provided by different sub-metalens in the same direction is less than or equal to a preset angle threshold.

7. The metalens according to claim 1, wherein: All layered regions in at least one superimposed layer form an annular region.

8. The metalens according to claim 1, characterized in that All vertices of each sub-region are located at the boundary of the layered region.

9. The metalens according to claim 1, characterized in that The metalens is also used to provide a collimated phase to the incident light as a whole.

10. A light homogenization module, characterized in that: The light homogenization module comprises: a light source; a super lens as described in any one of claims 1 to 9; The super lens is arranged on the light emitting side of the light source.

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