Super lens for dodging, dodging system and light beam scanning system

Abstract

The utility model provides a super lens for dodging, a dodging system and a light beam scanning system. The super lens is used for at least providing a shaping phase for the light received at each position on the super lens so as to modulate the light received at each position on the super lens; after modulation, the light received at each position on the super lens is emitted according to a corresponding target emergent angle; the light intensity of light beams emitted by the super lens is uniformly distributed in at least one direction; in addition, the optical axis of the light beam emitted by the super lens is perpendicular to the super lens or inclined to the super lens. The light beams emitted by the super lens provided by the utility model can be projected to obtain small-distortion or even distortion-free light spots no matter whether the light beams are emitted in a normal mode or in an inclined mode, and the super lens has higher universality in dodging application.

Description

Technical Field

[0001] The utility model relates to the technical field of light homogenization, and in particular to a super lens, a light homogenization system and a light beam scanning system for light homogenization. Background Art

[0002] In the field of light homogenization technology, traditional related technologies often use hyperbolic lenses and microlens arrays to shape the light beam emitted by the light source into a normal outgoing light beam, and then project a light spot with a specific shape and uniform light intensity distribution on the target plane. However, in some special application scenarios, such as in smart devices such as sweeping robots, it is necessary to achieve oblique downward lighting and identify objects on the ground, which requires the ability to generate an oblique outgoing light beam. At the same time, it is necessary to control the light spot projected by the oblique outgoing light beam to have a uniform light intensity distribution and to be as distortion-free as possible, so as to ensure that the performance of the light spot projected by the oblique outgoing light beam will not be significantly different from that of the light spot projected by the normal outgoing light beam.

[0003] By only using hyperbolic lenses and microlens arrays, the related art has difficulty in controlling the light spot obtained by projecting an oblique light beam to have uniform light intensity distribution and no distortion. For this reason, the related art needs to redesign a corresponding light homogenization device for the case of oblique light homogenization. In this way, the related art needs to provide a specific light homogenization device for the case of normal light homogenization, and another specific light homogenization device for the case of oblique light homogenization. It can be seen that the light homogenization device provided by the related art is less versatile. Utility Model Content

[0004] One purpose of the present application is to provide a metalens, a light homogenization system, and a beam scanning system for light homogenization. The light beam emitted by the metalens provided in the present application, whether it is normal emission or oblique emission, can project a light spot with little or no distortion, and has higher versatility in light homogenization applications.

[0005] According to one aspect of an embodiment of the present application, a metalens for uniform light is disclosed, wherein the metalens is used to provide at least a shaping phase for light received at various positions on the metalens, so as to modulate the light received at various positions on the metalens; after modulation, the light received at various positions on the metalens is emitted according to the corresponding target emission angle;

[0006] The light intensity of the light beam emitted by the super lens is uniformly distributed in at least one direction; and the optical axis of the light beam emitted by the super lens is perpendicular to the super lens, or inclined to the super lens.

[0007] In an exemplary embodiment of the present application, the target emission angle includes a first target emission angle relative to a first coordinate axis on the two-dimensional plane where the metalens is located, and a second target emission angle relative to a second coordinate axis on the two-dimensional plane where the metalens is located; the first coordinate axis and the second coordinate axis are not parallel to each other;

[0008] The shaping phase is obtained by performing a second type of curve integration on the phase gradient corresponding to the first target emission angle in the direction of the first coordinate axis and the phase gradient corresponding to the second target emission angle in the direction of the second coordinate axis.

[0009] In an exemplary embodiment of the present application, the shaping phase satisfies:

[0010]

[0011]

[0012]

[0013] in, represents the shaping phase, (x1, y1) represents the position on the super lens, (x2, y2) represents the position on the light receiving surface, (x1, y1) and (x2, y2) have a mapping relationship, r represents the distance between the position (x1, y1) on the super lens with a mapping relationship and the position (x2, y2) on the light receiving surface, k represents the wave number, α represents the first target output angle, and β represents the second target output angle.

[0014] In an exemplary embodiment of the present application, the mapping relationship between the position (x1, y1) on the metalens and the position (x2, y2) on the light receiving surface satisfies:

[0015] ∫I1dx1dy1=∫I2dx2dy2

[0016] I1(x1,y1)dx1dy1=I2(x2,y2)dx2dy2

[0017] Wherein, I1 represents the light intensity distribution received at each position on the metalens, and I2 represents the target light intensity distribution of the light beam emitted by the metalens on the light receiving surface.

[0018] In an exemplary embodiment of the present application, the metalens is also used to provide a collimated phase for light received at various positions thereon.

[0019] In an exemplary embodiment of the present application, the collimation phase satisfies:

[0020]

[0021] in, represents the collimation phase, (x1, y1) represents the position on the super lens, k represents the wave number, and f represents the focal length of the super lens.

[0022] According to one aspect of an embodiment of the present application, a light homogenization system is disclosed, and the light homogenization system includes: a light source and a super lens as described in any one of the above embodiments.

[0023] In an exemplary embodiment of the present application, if the target plane is parallel to the superlens, the light spot obtained by projecting the light beam emitted by the superlens on the target plane has a uniform light intensity distribution in the first direction, and the light intensity of the two end areas of the light spot in the second direction is greater than the light intensity of the middle area of ​​the light spot in the second direction; the first direction is perpendicular to the second direction.

[0024] In an exemplary embodiment of the present application, if the target plane is parallel to the metalens, the light spot obtained by projecting the light beam emitted by the metalens on the target plane has a uniform light intensity distribution in the first direction, and the light intensity of the light spot gradually decreases from the first end of the light spot in the second direction to the second end of the light spot in the second direction; the first direction is perpendicular to the second direction;

[0025] The super lens is inclined to the target plane, and the projection distance of the first end of the light spot in the second direction is greater than the projection distance of the second end of the light spot in the second direction, so as to uniformly fill the target plane with light.

[0026] According to one aspect of an embodiment of the present application, a light beam scanning system is disclosed, the light beam scanning system comprising: at least two light homogenization systems as described in the above embodiment; a light source control module; each of the light homogenization systems is electrically connected to the light source control module;

[0027] At least two of the light homogenization systems are arranged and distributed in the same direction according to the target pattern on the same plane, and under the control of the light source control module, the light source of each of the light homogenization systems is lit in turn to scan the target object.

[0028] In the above-mentioned metalens, homogenizing system and beam scanning system, when light passes through the metalens, a specific shaping phase is applied at various positions on the metalens to change the phase distribution of the light, thereby controlling the propagation direction of the light so that it is emitted at a predetermined target emission angle to achieve the effect of homogenizing. Only by using this metalens, the light received at various positions can be controlled to be emitted according to the target emission angle required by the design. Therefore, whether the light beam emitted by the metalens is perpendicular to the metalens or tilted to the metalens, it will not exceed the modulation capacity of the metalens. Therefore, the optical axis of the light beam emitted by the metalens can be perpendicular to the metalens or tilted to the metalens. Therefore, the light beam emitted by the metalens provided in the present application, whether it is positive emission or oblique emission, can project a light spot with small distortion or even no distortion, and has higher versatility in homogenizing applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 A schematic diagram of obtaining a uniform light spot by projecting a superlens in one embodiment of the present application is shown.

[0031] Figure 2 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in a normal emission manner using a uniform light system in an embodiment of the present application.

[0032] Figure 3 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in a normal emission manner using a uniform light system in an embodiment of the present application.

[0033] Figure 4 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in a normal emission manner using a uniform light system in an embodiment of the present application.

[0034] Figure 5 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in a normal emission manner using a uniform light system in an embodiment of the present application.

[0035] Figure 6 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in a normal emission manner using a uniform light system in an embodiment of the present application.

[0036] Figure 7A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in a normal emission manner using a uniform light system in an embodiment of the present application.

[0037] Figure 8 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in a normal emission manner using a uniform light system in an embodiment of the present application.

[0038] Fig. 9 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in an eccentric emission manner using a uniform light system in one embodiment of the present application.

[0039] Fig.10 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in an eccentric emission manner using a uniform light system in one embodiment of the present application.

[0040] Fig.11 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in an eccentric emission manner using a uniform light system in one embodiment of the present application.

[0041] Fig.12 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in a normal emission manner using a uniform light system in an embodiment of the present application.

[0042] Fig.13 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in a normal emission manner using a uniform light system in an embodiment of the present application.

[0043] Fig.14 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in a normal emission manner using a uniform light system in an embodiment of the present application.

[0044] Fig.15 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in a normal emission manner using a uniform light system in an embodiment of the present application.

[0045] Fig.16 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in a normal emission manner using a uniform light system in an embodiment of the present application.

[0046] Fig.17 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in a normal emission manner using a uniform light system in an embodiment of the present application.

[0047] Fig.18 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in a normal emission manner using a uniform light system in an embodiment of the present application.

[0048] Fig.19 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in a normal emission manner using a uniform light system in an embodiment of the present application.

[0049] Fig. 20 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in a normal emission manner using a uniform light system in an embodiment of the present application.

[0050] Fig.21 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in a normal emission manner using a uniform light system in an embodiment of the present application.

[0051] Fig. 22 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in an eccentric emission manner using a uniform light system in one embodiment of the present application.

[0052] Fig.23 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in an eccentric emission manner using a uniform light system in one embodiment of the present application.

[0053] Fig.24 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in an eccentric emission manner using a uniform light system in one embodiment of the present application.

[0054] Fig.25 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in a normal emission manner using a uniform light system in an embodiment of the present application.

[0055] Fig.26 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in a normal emission manner using a uniform light system in an embodiment of the present application.

[0056] Fig. 27 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in a normal emission manner using a uniform light system in an embodiment of the present application.

[0057] Fig.28 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in an eccentric emission manner using a uniform light system in one embodiment of the present application.

[0058] Fig.29 A schematic diagram showing a uniform light spot and a corresponding light intensity distribution obtained by projecting a uniform light spot in a normal emission manner using a uniform light system in an embodiment of the present application.

[0059] Fig.30 Shows Fig.29 A schematic diagram of a usage scenario to which the embodiment is applicable.

[0060] Fig.31 Shows Fig.30 In the usage scenario involved in the embodiment, a schematic diagram of a uniform light spot and a corresponding light intensity distribution obtained by obliquely projecting a uniform light system onto a target plane.

[0061] Fig.32 It shows that in one embodiment of the present application, 5 Fig.29 A schematic diagram of a uniform light spot projected when the uniform light system provided in the embodiment performs splicing and fill light.

[0062] Fig.33 The schematic diagram of the light beam scanning system in one embodiment of the present application is shown.

[0063] Fig.34 Shows Fig.33 Schematic diagram of the internal layout of the light beam scanning system in an embodiment.

[0064] Fig.35 Shows Fig.33 Schematic diagram of the far-field light intensity of only A being illuminated by the beam scanning system in the embodiment.

[0065] Fig.36 Shows Fig.33 Schematic diagram of the far-field light intensity of only lighting up B1 by the beam scanning system in the embodiment.

[0066] Fig.37 Shows Fig.33 Schematic diagram of the far-field light intensity of only lighting B2 in the beam scanning system in the embodiment.

[0067] Fig.38 Shows Fig.33 Schematic diagram of the far-field light intensity of only lighting C1 in the embodiment of the light beam scanning system.

[0068] Fig.39 Shows Fig.33 Schematic diagram of the far-field light intensity of C2 when the beam scanning system in the embodiment illuminates only C2.

[0069] Fig.40 Shows Fig.33 Schematic diagram of the far-field light intensity when all beam scanning systems are lit in the embodiment.

[0070] Reference numerals:

[0071] 102 - light source; 104 - super lens; 106 - light receiving surface. DETAILED DESCRIPTION

[0072] The present invention will now be described more fully below with reference to the accompanying drawings, in which various embodiments are shown. However, the present invention can be implemented in many different ways and should not be construed as being limited to the embodiments set forth in the present invention. On the contrary, these embodiments are provided so that the present invention will be detailed and complete, and will fully convey the scope of the present invention to those skilled in the art. The same reference numerals throughout the text represent the same components. Furthermore, in the accompanying drawings, the thickness, ratios, and sizes of the components are exaggerated for clarity of illustration.

[0073] The terms used in the present invention are only used for the purpose of describing specific embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, "one", "the", "at least one" as used in the present invention do not represent a limitation on quantity, but are intended to include both the singular and the plural. For example, unless the context clearly indicates otherwise, "a component" has the same meaning as "at least one component". "At least one" should not be interpreted as being limited to the number "one". "Or" means "and / or". The term "and / or" includes any and all combinations of one or more of the associated listed items.

[0074] Unless otherwise defined, all terms used in the present invention, including technical terms and scientific terms, have the same meanings as those generally understood by those skilled in the art. Terms defined in commonly used dictionaries should be interpreted as having the same meanings as in the relevant technical context, and unless clearly defined in the specification, these terms are not interpreted as having formal meanings in an idealized or overly formal sense.

[0075] The meaning of “include” or “comprising” specifies properties, quantities, steps, operations, components, parts or a combination thereof, but does not exclude other properties, quantities, steps, operations, components, parts or a combination thereof.

[0076] Although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.

[0077] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature as shown in the figure, such as "inside", "outside", "inner side", "outer side", "below", "below", "above", "above", etc. Such spatial relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figure. For example, if the device in the figure is turned over, the element described as "below other elements or features" or "below other elements or features" will be subsequently oriented as "above other elements or features" or "above other elements or features". Therefore, the example term "below ..." may include both upper and lower orientations. The device may be otherwise oriented, such as rotated 90 degrees or in other directions, and the spatial relative descriptors used in the text are interpreted accordingly.

[0078] The present invention describes embodiments with reference to cross-sectional views as idealized embodiments. Thus, variations in shape relative to the illustrated diagram are foreseen as a result of, for example, manufacturing techniques and / or tolerances. Therefore, the embodiments described in the present invention should not be interpreted as being limited to the specific shapes of the regions shown in the present invention, but should include deviations in shapes due to, for example, manufacturing. For example, a region shown or described as flat may typically have rough and / or nonlinear features. Moreover, the sharp angles shown may be rounded. Therefore, the regions shown in the figures are schematic in nature, and their shapes are not intended to illustrate the precise shapes of the regions and are not intended to limit the scope of the claims.

[0079] The present application provides a metalens for light homogenization. The metalens is used to provide at least a shaping phase for the light received at various positions on it, so as to modulate the light received at various positions on it. After modulation, the metalens emits the light received at various positions on it according to the corresponding target emission angle.

[0080] The super lens includes a substrate and a micro-nano structure disposed on the substrate. By adjusting the parameters of the micro-nano structure, such as the material, height, cross-sectional area, cross-sectional shape, and arrangement period, the micro-nano structure can provide the shaping phase required by the design with a high degree of freedom. Therefore, without introducing other optical elements, the super lens can be used to control the light received at various positions to be emitted according to the target emission angle required by the design, so that the projected light spot not only has a uniform light intensity distribution, but also has very small or even no distortion. Figure 1As shown, when the light emitted by the light source 102 irradiates the metalens 104, each position on the metalens 104 can apply a corresponding shaping phase to the light to change the phase distribution of the light, thereby controlling the propagation direction of the light, so that the light is emitted from the metalens 104 according to a predetermined target exit angle, and forms a light spot with uniform light intensity distribution on the light receiving surface 106, and the light spot has little or no distortion.

[0081] Specifically, the light intensity of the light beam emitted by the metalens is uniformly distributed along at least one direction, and accordingly, the light intensity of the light spot projected by the light beam emitted by the metalens is uniformly distributed along at least one direction. The light intensity of the light spot is uniformly distributed along at least one direction, which means that the light intensity of the light spot can be uniformly distributed along only one direction or in multiple directions at the same time. Figure 1 As shown, the light beam emitted by the superlens 104 is projected onto the light receiving surface 106 parallel to the superlens 104, and the two-dimensional coordinate system corresponding to the light receiving surface 106 includes an x-axis and a y-axis that are not parallel to each other. The light intensity of the projected light spot can be evenly distributed only on the y-axis and unevenly distributed on the x-axis; or, the light intensity of the projected light spot can be evenly distributed on both the x-axis and the y-axis.

[0082] As described above, only the metalens can be used to control the light received at various locations to be emitted according to the target emission angle required by the design. Therefore, no matter whether the light beam emitted by the metalens is perpendicular to the metalens or tilted to the metalens, it will not exceed the modulation capability of the metalens. Therefore, the optical axis of the light beam emitted by the metalens can be perpendicular to the metalens or tilted to the metalens. Figure 1 As shown, Figure 1 The angle θ in is the eccentric angle of the light beam emitted by the metalens 104, which is the angle between the optical axis of the light beam and the normal line of the metalens 104. When the optical axis of the light beam emitted by the metalens 104 is perpendicular to the metalens 104, the eccentric angle θ is 0 degrees; when the optical axis of the light beam emitted by the metalens 104 is inclined to the metalens 104, the eccentric angle θ is greater than 0 degrees.

[0083] That is, the metalens can be used for normal emission homogenization or oblique emission homogenization. Therefore, the light beam emitted by the metalens provided in the present application, whether normal emission or oblique emission, can project a light spot with little or no distortion, and has higher versatility in the application of homogenization.

[0084] In one embodiment, the target emission angle includes a first target emission angle relative to a first coordinate axis on the two-dimensional plane where the metalens is located, and a second target emission angle relative to a second coordinate axis on the two-dimensional plane where the metalens is located. The first coordinate axis and the second coordinate axis are not parallel to each other.

[0085] The shaping phase is obtained by performing a second type curve integration on the phase gradient corresponding to the first target emission angle in the direction of the first coordinate axis and the phase gradient corresponding to the second target emission angle in the direction of the second coordinate axis.

[0086] Specifically, the target exit angle refers to the angle at which the light leaves the surface of the metalens after being modulated by the metalens. This angle includes the exit angles in two directions, namely the first target exit angle and the second target exit angle, which correspond to two non-parallel coordinate axes on the two-dimensional plane where the metalens is located: the first coordinate axis and the second coordinate axis. In a specific example, the first coordinate axis can be defined as the x-axis, and the second coordinate axis can be defined as the y-axis. It can be understood that the metalens has the ability to regulate the exit angles of light in these two different directions.

[0087] The shaping phase is calculated by performing a second-type curve integral on the phase gradients in the above two directions at the same time. The second-type curve integral, also known as the curve integral about coordinates, is the integration of the vector field along a specific curve. At different positions of the metalens, the applied shaping phase can be the same or different, depending on the specific requirements of the light emission. In this way, it can be ensured that the light spot projected by the light beam emitted by the metalens will not be significantly distorted. Therefore, the light beam emitted by the metalens, whether it is normal or oblique, can project a light spot with little or no distortion.

[0088] As mentioned above, the shaping phase is calculated by integrating the second type of curve. Based on this, in one embodiment, the shaping phase is calculated based on the following conditional formula:

[0089]

[0090]

[0091]

[0092] in, represents the shaping phase, (x1, y1) represents the position on the metalens, (x2, y2) represents the position on the light receiving surface, (x1, y1) and (x2, y2) have a mapping relationship, r represents the distance between the position (x1, y1) on the metalens with a mapping relationship and the position (x2, y2) on the light receiving surface, k represents the wave number, α represents the first target output angle, β represents the second target output angle, k cosα represents the phase gradient corresponding to the first target output angle in the direction of the first coordinate axis, and k cosβ represents the phase gradient corresponding to the second target output angle in the direction of the second coordinate axis.

[0093] It can be seen from the above embodiments that the target emission angle includes a first target emission angle and a second target emission angle. These two target emission angles are calculated based on the position (x1, y1) on the metalens with a mapping relationship and the position (x2, y2) on the light receiving surface. It can be seen that in order to meet the requirement that light is emitted at the target emission angle in the metalens, it is first necessary to clarify the mapping relationship between the position (x1, y1) at each location on the metalens and the position (x2, y2) at each location on the light receiving surface. In one embodiment, this mapping relationship is determined based on the law of conservation of energy. Exemplarily, the mapping relationship can be specifically determined based on the following conditional formula:

[0094] ∫I1dx1dy1=vI2dx2dy2

[0095] I1(x1,y1)dx1dy1=I2(x2,y2)dx2dy2

[0096] Among them, I1 represents the light intensity distribution received at various positions on the metalens, and I2 represents the target light intensity distribution of the light beam emitted by the metalens on the light receiving surface.

[0097] In this embodiment, the energy distribution relationship between each position on the metalens and each position on the light receiving surface is established based on the law of conservation of energy. This method is in line with scientific principles and is conducive to ensuring the accuracy and reliability of the mapping relationship.

[0098] In other embodiments, the mapping relationship between various positions on the metalens and various positions on the light receiving surface can also be obtained by other implementation methods. For example, an iterative optimization algorithm can be used to obtain an ideal mapping relationship through a continuous iterative calculation process. In a specific example, the Newton iteration method is used to calculate the mapping relationship between (x1, y1) and (x2, y2). The goal of this method is to minimize the average deflection angle (the deflection angle from (x1, y1) to (x2, y2)) as much as possible based on the minimum transmission cost theory. For example, an experimental measurement method can also be used to reversely deduce the mapping relationship by actually measuring the control effect of the metalens on light.

[0099] In one embodiment, the metalens is also used to provide a collimated phase for the light received at various positions thereon. It can be understood that in this embodiment, each position of the metalens can simultaneously apply a shaping phase and a collimated phase to the light. Therefore, the total phase effect applied by the metalens to the light is a superposition of the shaping phase and the collimated phase. In this way, this embodiment realizes, on the one hand, controlling the emission direction of the light by the shaping phase, and on the other hand, ensuring that the light can propagate in a parallel or collimated form after passing through the metalens by the collimated phase.

[0100] In a specific example, the collimation phase satisfies the following conditional expression:

[0101]

[0102] in, represents the collimation phase, and f represents the focal length of the metalens.

[0103] Of course, the collimation phase can also be calculated using a variety of other methods, which can be selected based on specific application requirements and design goals.

[0104] Based on the same inventive concept, the present application also provides a light homogenization system, which includes a light source and the metalens involved in the above embodiment.

[0105] Specifically, the light source may be a VCSEL (Vertical-Cavity Surface-Emitting Laser), which is used to emit a light beam to the metalens.

[0106] Next, several embodiments provided in the present application are introduced, mainly to demonstrate that the metalens provided in the present application and the corresponding light homogenization system can project a light spot with small distortion or even no distortion in any illumination area (FOI, Field of Illumination) and any target exit angle, whether it is a point light source or a surface light source.

[0107] Embodiment 1

[0108] See also Figure 2 The light source is a VCSEL (Vertical-Cavity Surface-Emitting Laser) point light source with a wavelength of 940nm. The uniform light system projects a uniform light spot with a FOI of 30°x30° (VxH) in a positive emission mode. The observation distance of the light spot is 1m.

[0109] Embodiment 2

[0110] See also Figure 3 The light source is a VCSEL point light source with a wavelength of 940nm. The uniform light system projects a uniform light spot with a FOI of 60°x60° (VxH) in a positive emission mode. The observation distance of the light spot is 1m.

[0111] Embodiment 3

[0112] See also Figure 4 The light source is a VCSEL point light source with a wavelength of 940nm. The uniform light system projects a uniform light spot with a FOI of 90°x90° (VxH) in a normal emission mode. The observation distance of the light spot is 1m.

[0113] Embodiment 4

[0114] See also Figure 5 The light source is a VCSEL point light source with a wavelength of 940nm. The uniform light system projects a uniform light spot with a FOI of 120°x120°(VxH) in a normal emission mode. The observation distance of the light spot is 1m.

[0115] Embodiment 5

[0116] See also Figure 6 The light source is a VCSEL point light source with a wavelength of 940nm. The uniform light system projects a uniform light spot with a FOI of 30°x60° (VxH) in a normal emission mode. The observation distance of the light spot is 1m.

[0117] Embodiment 6

[0118] See also Figure 7 The light source is a VCSEL point light source with a wavelength of 940nm. The uniform light system projects a uniform light spot with a FOI of 30°x90° (VxH) in a normal emission mode. The observation distance of the light spot is 1m.

[0119] Embodiment 7

[0120] See also Figure 8 The light source is a VCSEL point light source with a wavelength of 940nm. The uniform light system projects a uniform light spot with a FOI of 30°x120°(VxH) in a normal emission mode. The observation distance of the light spot is 1m.

[0121] Embodiment 8

[0122] See also Fig. 9 The light source is a VCSEL point light source with a wavelength of 940nm. The uniform light system projects a uniform light spot with an eccentric emission angle of 5° and a FOI of 30°x60° (VxH). The observation distance of the spot is 1m.

[0123] Embodiment 9

[0124] See also Fig.10 The light source is a VCSEL point light source with a wavelength of 940nm. The uniform light system projects a uniform light spot with an eccentric emission angle of 10° and a FOI of 30°x60° (VxH). The observation distance of the spot is 1m.

[0125] Embodiment 10

[0126] See also Fig.11The light source is a VCSEL point light source with a wavelength of 940nm. The uniform light system projects a uniform light spot with an eccentricity of 15° and a FOI of 30°x60° (VxH). The observation distance of the light spot is 1m.

[0127] Embodiment 11

[0128] See also Fig.12 The light source is a VCSEL point light source with a wavelength of 940nm. The uniform light system projects a uniform light spot with a FOI of 60°x90° (VxH) in a normal emission mode. The observation distance of the light spot is 1m.

[0129] Embodiment 12

[0130] See also Fig.13 The light source is a VCSEL point light source with a wavelength of 940nm. The uniform light system projects a uniform light spot with a FOI of 60°x120°(VxH) in a normal emission mode. The observation distance of the light spot is 1m.

[0131] Embodiment 13

[0132] See also Fig.14 The light source is a VCSEL point light source with a wavelength of 940nm. The uniform light system projects a uniform light spot with a FOI of 90°x120° (VxH) in a normal emission mode. The observation distance of the light spot is 1m.

[0133] Embodiment 14

[0134] See also Fig.15 The light source uses a VCSEL point light source array with a wavelength of 940nm and an area of ​​500μm x 500μm. The uniform light system projects a uniform light spot with a FOI of 30°x30° (VxH) in a normal emission mode. The observation distance of the light spot is 1m.

[0135] Embodiment 15

[0136] See also Fig.16 The light source is a VCSEL point light source array with a wavelength of 940nm and an area of ​​500μm x 500μm. The uniform light system projects a uniform light spot with a FOI of 60°x60° (VxH) in a normal emission mode. The observation distance of the light spot is 1m.

[0137] Embodiment 16

[0138] See also Fig.17The light source is a VCSEL point light source array with a wavelength of 940nm and an area of ​​500μm x 500μm. The uniform light system projects a uniform light spot with a FOI of 90°x90° (VxH) in a normal emission mode. The observation distance of the light spot is 1m.

[0139] Embodiment 17

[0140] See also Fig.18 The light source is a VCSEL point light source array with a wavelength of 940nm and an area of ​​500μm x 500μm. The uniform light system projects a uniform light spot with a FOI of 120°x120° (VxH) in a normal emission mode. The observation distance of the light spot is 1m.

[0141] Embodiment 18

[0142] See also Fig.19 The light source uses a VCSEL point light source array with a wavelength of 940nm and an area of ​​500μm x 500μm. The uniform light system projects a uniform light spot with a FOI of 30°x60° (VxH) in a normal emission mode. The observation distance of the light spot is 1m.

[0143] Embodiment 19

[0144] See also Fig. 20 The light source uses a VCSEL point light source array with a wavelength of 940nm and an area of ​​500μm x 500μm. The uniform light system projects a uniform light spot with a FOI of 30°x90° (VxH) in a normal emission mode. The observation distance of the light spot is 1m.

[0145] Embodiment 20

[0146] See also Fig.21 The light source uses a VCSEL point light source array with a wavelength of 940nm and an area of ​​500μm x 500μm. The uniform light system projects a uniform light spot with a FOI of 30°x120° (VxH) in a normal emission mode. The observation distance of the light spot is 1m.

[0147] Embodiment 21

[0148] See also Fig. 22 The light source uses a VCSEL point light source array with a wavelength of 940nm and an area of ​​500μm x 500μm. The uniform light system projects a uniform light spot with an eccentric 5° FOI of 30°x60° (VxH) in an eccentric emission mode. The observation distance of the spot is 1m.

[0149] Embodiment 22

[0150] See also Fig.23 The light source uses a VCSEL point light source array with a wavelength of 940nm and an area of ​​500μm x 500μm. The uniform light system projects a uniform light spot with an eccentricity of 10° and a FOI of 30°x60° (VxH) in an eccentric emission mode. The observation distance of the spot is 1m.

[0151] Embodiment 23

[0152] See also Fig.24 The light source uses a VCSEL point light source array with a wavelength of 940nm and an area of ​​500μm x 500μm. The uniform light system projects a uniform light spot with an eccentricity of 15° and a FOI of 30°x60° (VxH) in an eccentric emission mode. The observation distance of the light spot is 1m.

[0153] Embodiment 24

[0154] See also Fig.25 The light source uses a VCSEL point light source array with a wavelength of 940nm and an area of ​​500μm x 500μm. The uniform light system projects a uniform light spot with a FOI of 60°x90° (VxH) in a normal emission mode. The observation distance of the light spot is 1m.

[0155] Embodiment 25

[0156] See also Fig.26 The light source uses a VCSEL point light source array with a wavelength of 940nm and an area of ​​500μm x 500μm. The uniform light system projects a uniform light spot with a FOI of 60°x120° (VxH) in a normal emission mode. The observation distance of the light spot is 1m.

[0157] Embodiment 26

[0158] See also Fig. 27 The light source uses a VCSEL point light source array with a wavelength of 940nm and an area of ​​500μm x 500μm. The uniform light system projects a uniform light spot with a FOI of 90°x120° (VxH) in a normal emission mode. The observation distance of the light spot is 1m.

[0159] In one embodiment, if the target plane is parallel to the metalens, the light spot obtained by projecting the light beam emitted by the metalens on the target plane has a uniform light intensity distribution in the first direction, and the light intensity of the two end regions of the light spot in the second direction is greater than the light intensity of the middle region of the light spot in the second direction. The first direction and the second direction are both located in the target plane, and the first direction is perpendicular to the second direction.

[0160] In the present embodiment, the reason why the light intensity of the two end regions of the light spot in the second direction is configured to be greater than the light intensity of the middle region during design is because it is taken into consideration that when the length of the light spot in the second direction is large, the light propagation distance of the two end regions in the second direction will be significantly greater than the light propagation distance of the middle region in the second direction. Therefore, in actual applications, the light energy loss of the two end regions in the second direction will be significantly greater than the light energy loss of the middle region in the second direction.

[0161] In this way, if the light intensity of the two end regions in the second direction is designed to be consistent with the light intensity of the middle region in the second direction, the image sensor actually senses that the light intensity of the two end regions in the second direction is significantly lower than the light intensity of the middle region in the second direction. Therefore, for the image sensor, the light intensity of the light spot is not evenly distributed.

[0162] Therefore, in this embodiment, the light intensity of the two end regions of the light spot in the second direction is configured to be greater than the light intensity of the middle region during design; in this way, the light intensity of the two end regions in the second direction actually sensed by the image sensor is basically consistent with the light intensity of the middle region in the second direction. Therefore, for the image sensor, the light intensity of the light spot is evenly distributed.

[0163] Specifically, in one example, see Fig.28 The light source is a VCSEL point light source array with a wavelength of 850nm and an area of ​​600μm x 500μm (VxH). The uniform light system projects a uniform light spot with an eccentricity of about 30° and a FOI of 40°x120° (VxH) in an eccentric emission mode. The observation distance of the light spot is 1m. The light intensity of the light spot in the y-axis direction is basically evenly distributed; after special modulation, the light intensity of the two end areas of the light spot in the x-direction is greater than the light intensity of the middle area in the x-direction.

[0164] It should be noted that the target plane and the light receiving surface mentioned above can be regarded as the same concept. The difference is that in this application, the light receiving surface represents a virtual ideal plane, while the target plane can represent both a virtual ideal plane and a plane in actual application (e.g., the ground).

[0165] In one embodiment, if the target plane is parallel to the metalens, the light spot obtained by projecting the light beam emitted by the metalens on the target plane has a uniform light intensity distribution in the first direction, and the light intensity of the light spot gradually decreases from the first end of the light spot in the second direction to the second end of the light spot in the second direction. The first direction and the second direction are both located in the target plane, and the first direction is perpendicular to the second direction.

[0166] In this embodiment, the superlens is actually inclined to the target plane, and the projection distance of the light spot at the first end in the second direction is greater than the projection distance of the light spot at the second end in the second direction, so as to uniformly fill in the target plane.

[0167] In this embodiment, this configuration is adopted because, in some applications of uniform light filling, the light homogenization system should not be parallel to the target plane as much as possible to avoid blocking the light of the target object (e.g., camera, main light source of the environment, etc.) vertically above the target plane; therefore, the light homogenization system needs to be tilted to face the target plane. Therefore, in this embodiment, the metalens is actually tilted to the target plane.

[0168] When designing a metalens, it is usually assumed that the target plane is parallel to the metalens for the sake of design convenience. The target plane changes from being parallel to the metalens, rotating around a certain rotation axis in the target plane, to being tilted to the metalens, and the light spot on the target plane will be deformed, especially in the vertical direction of the rotation axis in the target plane. In this embodiment, the vertical direction of the rotation axis in the target plane is recorded as the second direction, and the light propagation distance corresponding to each position in the second direction will be significantly inconsistent, that is, the projection distance corresponding to each position in the second direction will be significantly inconsistent.

[0169] Obviously, the greater the projection distance, the greater the light energy loss. Therefore, when designing the metalens and assuming that the target plane is parallel to the metalens, the light intensity of the light spot is configured to gradually decrease from the first end in the second direction to the second end of the light spot in the second direction; and when the metalens is configured to be inclined to the target plane, the projection distance of the first end in the second direction is controlled to be greater than the projection distance of the second end in the second direction. In this way, a light spot with uniform light intensity distribution is actually projected on the target plane.

[0170] Specifically, in Fig.29 In one example, the light source uses a VCSEL point light source array with a wavelength of 855nm and an area of ​​500μm x 500μm (VxH). The uniform light system projects a uniform light spot with a FOI of 45°x45° (VxH) in a positive emission mode. The observation distance of the light spot is 13m. After special modulation, the light intensity of the light spot gradually increases along the positive direction of the y-axis, and the light intensity of the x-axis is evenly distributed.

[0171] like Fig.30 As shown, Fig.29 In the light homogenization system provided in the embodiment, the metalens is tilted to the target plane, that is, the ground; the angle between the normal line of the metalens and the horizontal plane is 24°. Fig.31 As shown, Fig.29 The light homogenization system provided in the embodiment is according to Fig.30 When configured in the manner shown, the light spot projected by the uniform light system on the ground gradually widens along the positive direction of the y-axis, and its overall light intensity is evenly distributed, thereby providing uniform fill light to the ground.

[0172] Further, such as Fig.32 As shown, when 5 Fig.29 When the light homogenization systems provided in the embodiments are spliced ​​together, a full-range fill light effect with a viewing angle of 180° and a distance of 300 meters can be achieved.

[0173] The present application also provides a light beam scanning system. The light beam scanning system comprises: at least two light homogenization systems involved in the above embodiments; a light source control module; each light homogenization system is electrically connected to the light source control module;

[0174] At least two light homogenization systems are arranged and distributed in the same direction according to the target pattern on the same plane, and under the control of the light source control module, the light source of each light homogenization system is lit in turn to scan the target object.

[0175] Specifically, in Fig.33 In one example, the light source uses a VCSEL point light source array with a wavelength of 850nm and an area of ​​550μm×800μm (VxH). The beam scanning system is composed of 5 super lenses and light sources, including normal emission and eccentric emission at different angles, achieving a uniform light spot with a FOI of 135°×110° (VxH) at an observation distance of 2m.

[0176] Alternatively, if Fig.34 As shown in the figure, the system consisting of five metalenses and light sources can be flexibly arranged, not limited to longitudinal arrangement along the y direction. This is because different arrangements will only cause slight changes in the position of the emitted light, and have almost no effect on the large-angle light intensity distribution in the far field.

[0177] In addition, you can choose to control the lighting of different light sources separately to scan different angle areas in sequence, or choose to light up all light sources at the same time. Different lighting methods will produce different light intensity distributions, such as Figures 35 to 40 shown.

[0178] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any technical solution that can be easily thought of by a person skilled in the art within the technical scope disclosed by the utility model should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model shall be based on the protection scope of the claims.

Claims

1. A metalens for light homogenization, characterized in that: The metalens is used to provide at least a shaping phase for the light received at each position on the metalens, so as to modulate the light received at each position on the metalens; After modulation, the light received at each position on the metalens is emitted according to the corresponding target emission angle; The light intensity of the light beam emitted by the super lens is uniformly distributed in at least one direction; and the optical axis of the light beam emitted by the super lens is perpendicular to the super lens, or inclined to the super lens.

2. The metalens according to claim 1, characterized in that The target emission angle includes a first target emission angle relative to a first coordinate axis on the two-dimensional plane where the metalens is located, and a second target emission angle relative to a second coordinate axis on the two-dimensional plane where the metalens is located; the first coordinate axis and the second coordinate axis are not parallel to each other; The shaping phase is obtained by performing a second type of curve integration on the phase gradient corresponding to the first target emission angle in the direction of the first coordinate axis and the phase gradient corresponding to the second target emission angle in the direction of the second coordinate axis.

3. The metalens according to claim 2, characterized in that The shaping phase satisfies: in, represents the shaping phase, (x1, y1) represents the position on the super lens, (x2, y2) represents the position on the light receiving surface, (x1, y1) and (x2, y2) have a mapping relationship, r represents the distance between the position (x1, y1) on the super lens with a mapping relationship and the position (x2, y2) on the light receiving surface, k represents the wave number, α represents the first target output angle, and β represents the second target output angle.

4. The metalens according to claim 3, characterized in that The mapping relationship between the position (x1, y1) on the metalens and the position (x2, y2) on the light receiving surface satisfies: ∫I1dx1dy1=∫I2dx2dy2 I1(x1,y1)dx1dy1=I2(x2,y2)dx2dy2 Wherein, I1 represents the light intensity distribution received at each position on the metalens, and I2 represents the target light intensity distribution of the light beam emitted by the metalens on the light receiving surface.

5. The metalens according to claim 1, wherein: The metalens is also used to provide a collimated phase for light received at various locations thereon.

6. The superlens according to claim 5, characterized in that The collimation phase satisfies: in, represents the collimation phase, (x1, y1) represents the position on the super lens, k represents the wave number, and f represents the focal length of the super lens.

7. A light homogenization system, characterized in that: The light homogenization system comprises: a light source and a superlens as described in any one of claims 1 to 6.

8. The light homogenization system according to claim 7, characterized in that: If the target plane is parallel to the superlens, the light spot obtained by projecting the light beam emitted by the superlens on the target plane has a uniform light intensity distribution in the first direction, and the light intensity of the two end areas of the light spot in the second direction is greater than the light intensity of the middle area of ​​the light spot in the second direction; the first direction is perpendicular to the second direction.

9. The light homogenization system according to claim 7, characterized in that: If the target plane is parallel to the metalens, the light spot obtained by projecting the light beam emitted by the metalens on the target plane has a uniform light intensity distribution in the first direction, and the light intensity of the light spot gradually decreases from the first end of the light spot in the second direction to the second end of the light spot in the second direction; the first direction is perpendicular to the second direction; The super lens is inclined to the target plane, and the projection distance of the first end of the light spot in the second direction is greater than the projection distance of the second end of the light spot in the second direction, so as to uniformly fill the target plane with light.

10. A beam scanning system, characterized in that: The light beam scanning system comprises: at least two light homogenization systems as claimed in claim 7; a light source control module; each of the light homogenization systems is electrically connected to the light source control module; At least two of the light homogenization systems are arranged and distributed in the same direction according to the target pattern on the same plane, and under the control of the light source control module, the light source of each of the light homogenization systems is lit in turn to scan the target object.

Images