Light-emitting device using metasurface and method for emitting light therefrom

Abstract

A light-emitting device for promoting the growth of one or more plants. The device includes a light-emitting layer including one or more light-emitting diodes for emitting light and at least one light-conversion layer having one or more light-conversion units. Each light-conversion unit has a metasurface for adjusting one or more parameters of the light emitted from the light-emitting layer. In some embodiments, the light-emitting device may further include a polarization control layer sandwiched between the light-emitting layer and the light-conversion layer.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 62 / 862,853, filed June 18, 2019, and U.S. Provisional Patent Application No. 62 / 961,317, filed January 15, 2020, the contents of each of which are incorporated by reference in their entirety herein.

[0002] Field of Disclosure The present disclosure relates to light emitting methods, devices and systems, and in particular to light emitting methods, devices and systems that use metasurfaces to control emitted light. [Background technology]

[0003] background Light-emitting diodes (LEDs) are known in many industries and are widely used, mainly as low-power light indicators. In recent years, LEDs with increased power or luminosity have been developed and are being used as light sources for illumination. For example, LED lights, with improved energy efficiency, safety and reliability, are replacing other types of lights on the market, such as incandescent lamps and compact fluorescent lamps (CFLs). Since everyday lighting contributes significantly to the strain on the power grid and significantly increases the overall need for electricity generation, the energy efficiency of LEDs will play a key role in future energy conservation. LEDs will dominate the lighting market due to their energy efficiency.

[0004] Highly efficient LEDs are replacing traditional lighting solutions in a variety of applications such as flashlights, portable lights, lamps, street lights, etc. LEDs can be powered by different types of power sources such as batteries, traditional power grids, renewable energy systems and energy storage systems such as those using photovoltaic (PV) panels and battery banks, thereby allowing great flexibility in adapting the lighting solution to a specific usage scenario.

[0005] In many lighting solutions, it may be preferable to configure a light source, such as an LED light source, to emit directional light, for example to form a converging beam and a focus in a given area for improved illumination intensity, to form a parallel beam to reach a distant target, and / or to form a diverging light beam to illuminate a wide area. In some lighting solutions, the light direction of the light source may preferably be adjustable. In the prior art, light sources usually use mirrors or reflective surfaces to form directional light, and mechanical means are often used to redirect the mirrors or reflective surfaces to adjust the light direction. Such directional lighting means are usually relatively large in size, slow in response, and low in efficiency.

[0006] LEDs with increased power and / or luminosity are also being used as light sources for growing plants and the like. Such LEDs, sometimes called LED grow lights, offer various advantages such as providing precise wavelengths of light, high intensity, high efficiency, etc. LED grow lights are also advantageous for growing indoor plants as the process of growing plants can be carried out in a controlled environment with far fewer risks and other unwanted outdoor variables.

[0007] Plant growth occurs as a result of the process of "photosynthesis." As known in the art, the photosynthesis process uses energy from light to convert carbon dioxide (CO2) into organic matter. Specifically, light energy is absorbed through specialized proteins containing chlorophyll pigments present in photosynthetic cell membranes called chloroplasts. Photosynthetic cells are primarily found in the leaves of plants.

[0008] However, chlorophyll only absorbs energy from certain parts or colors of the light spectrum. The effective spectrum spans the blue and red spectrum. Plant leaves are usually green because the green part of the light spectrum is reflected. When the photosynthetic cells of the leaf die and the chlorophyll is decomposed, the other pigment molecules in the leaf have a large influence on the light reflection while the chlorophyll is decomposed to such an extent that the leaf shows only brown color.

[0009] Thus, it is known that different pigments of chlorophyll absorb light of specific wavelengths and contribute to photosynthesis, and the photosynthetic efficiency or rate is strongly correlated with the spectrum of illumination.

[0010] For example, rice grown under blue and red lighting has a higher photosynthetic efficiency than those grown under red lighting alone. Pea leaves grown under red LED light contain higher levels of beta-carotene than those grown under blue or white LED light.

[0011] Light intensity is another influencing factor in photosynthesis due to the response of photosynthetic organisms to high light intensity to reduce the effects of stress. Under red LED light, wheat seedlings produce chlorophyll at 100 μmol m -2 s -1 Accumulates at 500 μmol m -2 s -1 So it doesn't accumulate.

[0012] It is observed that plants typically absorb more of the blue light spectrum during early growth, and then more of the red light spectrum as the plant matures and during flowering. It is also observed that some plants have a high order component that makes them more sensitive to interactions with light polarization. For example, such plants may absorb or reflect light of certain polarization states more efficiently than light of other polarization states.

[0013] In addition, plants are able to sense the duration and time of illumination and alter their growth rate accordingly.

[0014] Plant cultivation using a fixed or broadly defined lighting configuration is neither energy efficient nor optimal for photosynthesis. Prior art LED growth lights usually provide light to plants without considering the aforementioned factors, and therefore cannot provide an optimized lighting configuration to optimize the physiological processes of growing plants. Moreover, different plants require different light characteristics (e.g., intensity, spectrum, polarization, time, etc.) to achieve the best growth performance. However, prior art LED growth lights cannot adapt to the requirements of plants and cannot present the appropriate light characteristics.

[0015] For example, conventional lighting systems such as LED panels used for indoor plant growth do not typically provide a uniform light distribution across the plant: their light distribution is often strongest at the center and has a gradually decreasing intensity away from the center.

[0016] FIG 1A shows a conventional light source 10 emitting a light beam 12 toward a square image plane 14 spaced from the light source 10. FIG 1B shows the light intensity distribution 16 on the image plane 14. As can be seen, the conventional light source 10 does not provide a uniform light distribution on the image plane 14. Rather, the light intensity distribution 16 on the image plane 14 is strongest at the center of the image plane 14 and gradually decreases away from the center. Moreover, the intensity distribution 16 is symmetric with respect to the point of incidence of the light beam 12 on the image plane 14.

[0017] 2A and 2B are diagrams illustrating the results of a 6×6 square meter (m2) measurement taken using ray tracing techniques and located approximately 3 meters (m) away from the panel 10. 2 1 shows the illumination pattern produced by the LED panel 10 in the image plane 14 of the optical fiber 10 shown in FIG. 1. The intensity distribution is clearly non-uniform.

[0018] Thus, a grow light using such a light source 10 that provides sufficient light to the periphery of the plant will result in over-illumination of the center of the plant, which will cause the plant to stunt its growth. On the other hand, providing sufficient illumination to the center of the plant will result in inefficient illumination of the periphery of the plant, which will also cause the plant to stunt its growth. Such intensity distribution is due to the symmetry of the image plane center for the light emitter.

[0019] Such a light source 10 may be undesirable in other applications: for example, street lights using such a light source 10 may produce glare and overall inefficient lighting.

[0020] LEDs are also used in indoor and outdoor displays that require careful control of various light properties such as intensity, polarization and / or time with rapid response. Summary of the Invention [Problem to be solved by the invention]

[0021] overview Thus, there is a continuing need for LED devices, systems and methods that provide controlled light characteristics. [Means for solving the problem]

[0022] According to one aspect of the present disclosure, a light emitting device is provided, the light emitting device includes: a light emitting layer for emitting light; and a light conversion layer coupled to the light emitting layer, the light conversion layer including one or more light conversion units, each light conversion unit including a metasurface for adjusting one or more parameters of light emitted from the light emitting layer.

[0023] In some embodiments, the light emitting layer includes one or more light emitting diodes (LEDs) for emitting light.

[0024] In some embodiments, the light conversion layer is printed onto the light emitting layer.

[0025] In some embodiments, the light-emitting layer includes one or more light-emitting units, the light conversion layer includes a housing having one or more receptacles for receiving the one or more metasurfaces, and the one or more receptacles are at positions corresponding to the positions of the one or more light-emitting units to align the one or more metasurfaces with the one or more light-emitting units.

[0026] In some embodiments, each of the one or more receivers includes an outwardly flaring inner surface having an inner opening for receiving light emitted from the light emitting layer and an outer opening for passing the received light, the outer opening having an area larger than the area of ​​the inner opening.

[0027] In some embodiments, the inner surface of each of the one or more receivers is reflective.

[0028] In some embodiments, a cross-section of the inner surface of each of the one or more receivers has a parabolic shape.

[0029] According to one aspect of the present disclosure, a light emitting device is provided, the light emitting device including: a light emitting layer for emitting light; and a light conversion layer including one or more light conversion units, each light conversion unit including a metasurface, at least one metasurface being polarization selective for selectively passing light emitted from the light emitting layer having a predetermined polarization state through the metasurface.

[0030] In some embodiments, each of the one or more metasurfaces comprises a plurality of nanoscale structures arranged in an asymmetric base geometry.

[0031] In some embodiments, the light emitting device further comprises a polarization control layer sandwiched between the light emitting layer and the light conversion layer for polarizing light emitted from the light emitting layer.

[0032] In some embodiments, the lighting device is a grow light for promoting the growth of one or more plants.

[0033] According to one aspect of the present disclosure, a light emitting device for promoting the growth of one or more plants is provided, the light emitting device includes a light emitting layer for emitting light, and at least one light conversion layer including one or more light conversion units, each light conversion unit including a metasurface for adjusting one or more parameters of the light emitted from the light emitting layer to optimize the lighting configuration of one or more plants.

[0034] According to one aspect of the present disclosure, a display device is provided, the display device includes: an emissive layer for emitting light; and at least one light conversion layer including one or more light conversion units, each light conversion unit including a metasurface for adjusting one or more parameters of the light emitted from the emissive layer to display one or more images.

[0035] According to one aspect of the present disclosure, a light emitting device is provided, the light emitting device including: a light emitting layer for emitting light; a polarization control layer coupled to the light emitting layer for polarizing light emitted from the light emitting layer; and at least one light conversion layer coupled to the polarization control layer, the at least one light conversion layer including one or more light conversion units, each light conversion unit including at least one metasurface, the at least one metasurface being polarization selective for selectively passing polarized light from the polarization control layer through the metasurface to switch between different illumination patterns or images.

[0036] According to one aspect of the present disclosure, a light emitting device is provided, the light emitting device including: a light emitting layer for emitting light; a polarization control layer coupled to the light emitting layer for polarizing the light emitted from the light emitting layer; and at least one light conversion layer coupled to the polarization control layer, the at least one light conversion layer including one or more light conversion units, each light conversion unit including at least one metasurface, the at least one metasurface being polarization selective for selectively passing polarized light from the polarization control layer through the metasurface to create a plurality of different illumination patterns or images at different locations.

[0037] According to one aspect of the present disclosure, a light emitting device is provided, the light emitting device including: a light emitting layer for emitting light toward a source field of view (FOV), and at least one metasurface layer in front of the light emitting layer for directing light emitted from the light emitting layer toward a first FOV having an angular spread smaller than the angular spread of the source FOV.

[0038] In some embodiments, the light emitting device further includes a polarization control layer sandwiched between the light emitting layer and the at least one light conversion layer, the polarization control layer configured to polarize light emitted from the light emitting layer to a first polarization state or a second polarization state in response to a control signal, and the at least one light conversion layer configured to direct light from the polarization control layer in the first polarization state toward a first FOV having an angular spread smaller than the angular spread of the radiation source FOV, and to direct light from the polarization control layer in the second polarization state toward a second FOV having an angular spread larger than the angular spread of the first FOV.

[0039] According to one aspect of the present disclosure, a light-emitting device is provided, the light-emitting device including: a light-emitting layer for emitting light; and a light-conversion layer in front of the light-emitting layer, the light-conversion layer including a plurality of light-conversion units, each light-conversion unit including a metasurface for directing light emitted from the light-emitting layer toward a target area to form a predetermined light distribution pattern.

[0040] In some embodiments, the predetermined light distribution pattern is a substantially uniform distribution of light energy on the target area.

[0041] In some embodiments, the plurality of metasurfaces includes a first set of metasurfaces for directing light emitted from the light-emitting layer toward a boundary of the target area, and a second set of metasurfaces for directing light emitted from the light-emitting layer toward a center of the target area to generate a substantially uniform light energy distribution on the target area.

[0042] According to one aspect of the present disclosure, there is provided a solar energy harvesting device, comprising: a photovoltaic layer having a plurality of photovoltaic cells, and at least one metasurface layer on a front side of the photovoltaic layer for substantially directing light to the photovoltaic layer without causing reflection at the photovoltaic layer.

[0043] In some embodiments, a solar energy harvesting device includes a plurality of metasurface layers for directing light at angles of incidence within a predetermined range so that it impinges perpendicularly on the photovoltaic layer.

[0044] According to one aspect of the present disclosure, a light emitting device is provided, the light emitting device including: a light emitting layer for emitting light; and at least one metasurface layer in front of the light emitting layer for directing light emitted from the light emitting layer in a first polarization state toward a first FOV and directing light emitted from the light emitting layer in a second polarization state toward a second FOV, the first FOV and the second FOV being superimposed and laterally offset from each other to form a three-dimensional (3D) perception for a user wearing glasses having lenses with different polarization states.

[0045] According to one aspect of the present disclosure, a light emitting device is provided, the light emitting device includes a light emitting layer for emitting light, and at least one metasurface layer in front of the light emitting layer for directing light emitted from the light emitting layer in a first polarization state toward a first FOV and directing light emitted from the light emitting layer in a second polarization state toward a second FOV, the first FOV and the second FOV being laterally offset from each other such that the first FOV is only visible to a first eye of a user at a predetermined distance and the second FOV is only visible to a second eye of a user at a predetermined distance to form a 3D perception for a user. [Brief description of the drawings]

[0046] BRIEF DESCRIPTION OF THE DRAWINGS [Figure 1A] FIG. 1 is a schematic diagram illustrating a prior art light source that emits a light beam toward a square image plane spaced from the light source. [Figure 1B] 1B shows the light intensity distribution on an image plane of light emitted from the prior art light source shown in FIG. 1A. [Figure 2A] FIG. 1 is a schematic diagram illustrating a prior art light emitting diode (LED) emitting a beam of light toward a square image plane away from the light source. [Figure 2B] 1 shows the illumination pattern on an image plane of light emitted from a prior art LED panel obtained using ray tracing. [Diagram 3] 1 is a schematic diagram illustrating the structure of a light-emitting device including an LED light-emitting layer and a light conversion layer having one or more metasurfaces according to some embodiments of the present disclosure. [Figure 4] FIG. 4 is a schematic exploded view of the light emitting device shown in FIG. [Diagram 5] 4 shows a light-conversion unit of the light-conversion layer of the light-emitting device shown in FIG. [Figure 6] An example of a metasurface structure for forming the light-conversion unit shown in FIG. 5 is shown. [Figure 7] FIG. 1 is a schematic exploded view of a light emitting device including an LED light emitting layer, a polarization control layer, and a Metasurface light conversion layer according to some embodiments of the present disclosure. [Figure 8A] 8 is a schematic diagram illustrating a pixel of a polarization control layer of the optical device shown in FIG. 7 according to some embodiments of the present disclosure. [Figure 8B] 8B is a schematic diagram showing pixels of a light conversion layer of the optical device shown in FIG. 7, which correspond to the pixels of the polarization control layer shown in FIG. 8A. [Figure 9A] 8 is a schematic diagram illustrating a pixel of a polarization control layer of the optical device shown in FIG. 7 according to further embodiments of the present disclosure. [Figure 9B] 9B is a schematic diagram showing pixels of a light conversion layer of the optical device shown in FIG. 7, which correspond to the pixels of the polarization control layer shown in FIG. 9A. [Figure 10A] 8 is a schematic diagram illustrating a pixel of a polarization control layer of the optical device shown in FIG. 7 according to further embodiments of the present disclosure. [Figure 10B] 10B is a schematic diagram showing pixels of a light conversion layer of the optical device shown in FIG. 7, which correspond to the pixels of the polarization control layer shown in FIG. 10A. [Figure 11A] FIG. 8 is a schematic diagram showing the light device shown in FIG. 7 for displaying two images in two directions according to the embodiment shown in FIGS. 8A and 8B or FIGS. 9A and 9B. [Figure 11B] FIG. 8 is a schematic diagram showing the light device shown in FIG. 7 for displaying two images in two directions according to the embodiment shown in FIGS. 8A and 8B or FIGS. 9A and 9B. [Figure 12] 8A and 8B, 9A and 9B or 10A and 10B, a schematic diagram showing the light device shown in FIG. 7 for displaying two images in two directions. [Figure 13] 1 is a schematic exploded view of a light emitting device having multiple fiber optic cables according to some embodiments of the present disclosure. [Figure 14] 4 is a conceptual diagram showing printing of a light conversion layer of the light emitting device shown in FIG. [Figure 15] FIG. 1 is a schematic diagram of a lighting system for promoting plant growth, according to some embodiments of the present disclosure. [Figure 16] FIG. 1 is a schematic diagram of a lighting system for promoting plant growth including a sensor for monitoring plant growth, according to some embodiments of the present disclosure. [Figure 17] 4 is a schematic diagram showing the structure of a solar cell layer incorporated in the light emitting device shown in FIG. [Figure 18] 1 is a schematic diagram illustrating the structure of a lighting system used as a lighting source or light source with controlled lighting patterns according to some embodiments of the present disclosure. [Figure 19] 19 illustrates an example of forming a cost function used by the lighting system shown in FIG. 18 to generate a lighting pattern. [Figure 20] 20 is a flow chart showing the process steps performed by the processing structure of the lighting system shown in FIG. 18 to find a global (or near-global) minimum of a cost function using gradient descent. [Figure 21] 21 illustrates optimization results of the process shown in FIG. 20 for generating an illumination pattern. [Figure 22]21 illustrates optimization results of the process shown in FIG. 20 for generating an illumination pattern. [Figure 23] 21 illustrates optimization results of the process shown in FIG. 20 for generating an illumination pattern. [Figure 24] 21 illustrates optimization results of the process shown in FIG. 20 for generating an illumination pattern. [Diagram 25] 21 illustrates optimization results of the process shown in FIG. 20 for generating an illumination pattern. [Figure 26] 1 is a schematic diagram illustrating the structure of a lighting system used as a lighting source or light source with controlled lighting patterns according to some embodiments of the present disclosure. [Figure 27A] FIG. 13 is a schematic diagram showing a segmented metasurface for generating boundaries of an intensity distribution in the image plane. [Figure 27B] FIG. 27B shows an illumination pattern in the image plane produced by the vertically split metasurface shown in FIG. 27A, in which the optical energy is substantially concentrated along the vertical boundaries of the target area. [Figure 27C] 27B shows an illumination pattern in the image plane produced by the horizontally split metasurface shown in FIG. 27A, in which the optical energy is substantially concentrated along the horizontal boundaries of the target area. [Figure 28] A conceptual diagram of light distribution substantially concentrated along the horizontal and vertical boundaries of a target area using the horizontally and vertically split metasurfaces shown in FIG. 27A is shown. [Figure 29A] FIG. 13 is a schematic diagram illustrating a converging metasurface for producing a light distribution substantially concentrated at the center of the image plane. [Figure 29B] FIG. 29B illustrates the illumination pattern in the image plane produced by the converging metasurface shown in FIG. [Diagram 30] A conceptual diagram of a substantially uniform light distribution on the image plane produced by the segmented metasurface shown in FIG. 27A and the converging metasurface shown in FIG. 29A is shown. [Diagram 31] 1 shows a substantially uniform light distribution on the image plane at different distances. [Diagram 32]1 illustrates an exemplary implementation of a topocentric vector control panel (TVCP) using an array of metasurfaces according to some embodiments of the present disclosure, the TVCP including a metasurface housing coupled to an emissive layer, the metasurface housing including a plurality of receivers that receive a plurality of metasurface units therein. [Diagram 33] 33 is a photograph showing a metasurface housing bonded to the emissive layer of the TVCP shown in FIG. 32. [Diagram 34] We show the nanoscale construction of metasurfaces with asymmetric base geometries for illuminating plants with specific polarization states. [Diagram 35] FIG. 1 is a schematic diagram illustrating light reflection occurring at the surface of a prior art photovoltaic cell. [Diagram 36] FIG. 1 is a schematic diagram showing a solar panel apparatus having a metasurface-based topocentric vector control panel (TVCP) on the front side of a photovoltaic panel to reduce light reflection on the surface of the photovoltaic panel. [Figure 37] FIG. 13 is a schematic diagram showing a solar panel apparatus with a metasurface-based TVCP on the front side of a photovoltaic panel to miniaturize the photovoltaic panel. [Figure 38] FIG. 38 is a schematic diagram showing a prior art solar panel arrangement having a photovoltaic panel without a TVCP, for comparison with the solar panel arrangement shown in FIG. 37. [Figure 39] FIG. 1 is a schematic diagram showing a prior art display having a field of view (FOV) with a wide angular spread. [Diagram 40] FIG. 1 is a schematic diagram illustrating a metasurface-based ultradirectional screen or display according to some embodiments of the present disclosure. [Diagram 41] 1 is a schematic diagram illustrating a variable field of view (VFOV) screen or display according to some embodiments of the present disclosure. [Diagram 42] 13A-13C are schematic diagrams illustrating VFOV screens or displays according to some other embodiments of the present disclosure. [Figure 43A]An example is shown of using a VFOV screen as shown in FIG. 42 to simultaneously display two images, where a first image is displayed within a first FOV having a wide angular spread, and a second image is displayed within a second FOV having a narrow angular spread, such that the second image is not visible to a user located only within the first FOV. [Figure 43B] An example is shown of using a VFOV screen as shown in FIG. 42 to simultaneously display two images, where a first image is displayed within a first FOV having a wide angular spread, and a second image is displayed within a second FOV having a narrow angular spread, such that the second image is not visible to a user located only within the first FOV. [Figure 43C] An example is shown of using a VFOV screen as shown in FIG. 42 to simultaneously display two images, where a first image is displayed within a first FOV having a wide angular spread, and a second image is displayed within a second FOV having a narrow angular spread, such that the second image is not visible to a user located only within the first FOV. [Fig. 43D] An example is shown of using a VFOV screen as shown in FIG. 42 to simultaneously display two images, where a first image is displayed within a first FOV having a wide angular spread, and a second image is displayed within a second FOV having a narrow angular spread, such that the second image is not visible to a user located only within the first FOV. [Figure 43E] An example is shown of using a VFOV screen as shown in FIG. 42 to simultaneously display two images, where a first image is displayed within a first FOV having a wide angular spread, and a second image is displayed within a second FOV having a narrow angular spread, such that the second image is not visible to a user located only within the first FOV. [Figure 43F] An example is shown of using a VFOV screen as shown in FIG. 42 to simultaneously display two images, where a first image is displayed within a first FOV having a wide angular spread, and a second image is displayed within a second FOV having a narrow angular spread, such that the second image is not visible to a user located only within the first FOV. [Figure 43G]An example is shown of using a VFOV screen as shown in FIG. 42 to simultaneously display two images, where a first image is displayed within a first FOV having a wide angular spread, and a second image is displayed within a second FOV having a narrow angular spread, such that the second image is not visible to a user located only within the first FOV. [Diagram 44] FIG. 1 is a schematic diagram illustrating a metasurface-based three-dimensional (3D) display viewable with glasses having polarized lenses, according to some embodiments of the present disclosure. [Diagram 45] FIG. 1 is a schematic diagram showing a metasurface-based 3D display viewable without glasses with polarized lenses, according to some embodiments of the present disclosure. [Figure 46] FIG. 1 is a schematic diagram showing a prior art solar panel having a light reflection problem. [Figure 47] FIG. 1 is a schematic diagram showing a prior art solar panel having a light reflection problem. [Figure 48] FIG. 1 is a schematic diagram illustrating a solar panel using metasurfaces to reduce or eliminate light reflection issues, according to some embodiments of the present disclosure. [Figure 49] FIG. 1 is a schematic diagram illustrating a solar panel using metasurfaces to reduce or eliminate light reflection issues, according to some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0047] Detailed Description Light-emitting device having a light-emitting layer and a light-conversion layer 3 and 4, a light emitting device (also referred to as a "lighting device" or "light device") is shown and generally identified with the reference numeral 100, according to some embodiments of the present disclosure. As used herein, a light emitting device may be a device for illumination, a device for promoting plant growth, or a device for displaying images or videos thereon.

[0048] The light emitting device 100 in these embodiments includes a light emitting layer 104 sandwiched between a substrate 102 and a light conversion layer 106 for emitting light 108 from the light emitting layer 104 through the light conversion layer 106. As the emitted light 108 passes through the light conversion layer 106, the light conversion layer 106 modulates one or more parameters of the light 108, such as amplitude or intensity, phase, polarization, pattern, direction, etc.

[0049] The light emitting layer 104 can be any suitable lighting device. In these embodiments, the light emitting layer 104 is printed, coated, or otherwise bonded to the substrate 102 and includes a plurality of light emitting diodes (LEDs) 110 arranged in a matrix, although other arrangements of LEDs 110 are readily available. As used herein, the LEDs 110 can be any suitable LEDs, such as conventional LEDs, quantum dot (QD) LEDs, and / or organic LEDs (OLEDs).

[0050] The light conversion layer 106 is printed, coated, or otherwise bonded to the light emitting layer 104 to adjust or otherwise convert parameters of the light emitted from the light emitting layer 104 (described in more detail below).

[0051] The light conversion layer 106 includes one or more light conversion units 122 arranged in a predetermined pattern, where each light conversion unit 122 includes a metasurface. As used herein, a metasurface is a two-dimensional array of nanostructures with subwavelength spacing and can be used to modulate electromagnetic waves. Details of metasurfaces are described in an academic paper entitled "LIGHT PROPAGATION WITH PHASE DISCONTINUITIES: GENERALIZED LAWS OF REFLECTION AND REFRACTION" by Nanfang Yu, Patrice Genevet, Mikhail A. Kats, Francesco Aieta, Jean-Philippe Tetienne, Federico Capasso, and Zeno Gaburro, Science volume 334, issue 6054, pages 333-337 (2011).

[0052] As shown in Figures 5 and 6, each metasurface unit 122 includes a metasurface having a subwavelength thickness (i.e., the subwavelength thickness is thinner than the wavelength of light emitted from the light emitting layer 104) and includes a plurality of nanoscale structures 124 periodically arranged in a specific order for precisely adjusting or transforming a property or parameter (e.g., amplitude or intensity, phase, polarization, pattern, direction, etc.) of the incident light, thereby enabling precise control of the properties of the light output therefrom.

[0053] In some embodiments, the nanoscale structures 124 (also referred to as "nanostructures") can be sub-wavelength structures made of suitable metallic or dielectric materials having one or more dimensions smaller than the wavelength of light emitted from the light emitting layer 104. In some embodiments, the nanoscale structures 124 can include a plurality of nanorods (also referred to as "antennas", see FIG. 6). In some embodiments, the nanoscale structures 124 can include a plurality of V-shaped nanorods. As discussed above, the nanoscale structures 124 can form a periodic or repeating pattern, with each pattern including a plurality of nanoscale structures 124 of different shapes and dimensions.

[0054] Depending on the shape and distribution of the nanostructures 124, the light conversion layer 106 can be configured to adjust or transform one or more parameters of the incident light.

[0055] For example, as shown in FIG. 4, the metasurface units 122A of the light conversion layer 106 can be configured to phase convert the incident light 108A and modify the direction of the incident light 108A to converge, thereby forming a converging light beam that focuses at a desired point spaced apart from the light conversion layer 106.

[0056] As another example, the metasurface units 122B of the light conversion layer 106 may be configured to phase convert the incident light 108B and modify the direction of the incident light 108B to be collimated, thereby forming a collimated light beam to reach a distant target.

[0057] As a further example, the metasurface units 122C of the light conversion layer 106 may be configured to phase convert the incident light 108C and modify the direction of the incident light 108C to diverge, thereby forming a diverging light beam to illuminate a large area.

[0058] In conventional grow light applications, one or more lighting devices (also called grow light devices) are used to emit light toward plants to promote plant growth. In these applications, some of the light emitted from the grow light device, such as the light emitted from the peripheral area of ​​the grow light device, may only partially impinge on the plants due to the divergence of the light beam, thereby causing light energy to be wasted. Such problems may be more serious when the plants are spaced apart from each other.

[0059] In some embodiments, the light emitting device 100 may be used as a grow light device that does not have the above problems or at least reduces the above problems. In these embodiments, the light conversion layer 106 or at least some of its metasurface units 122 may be designed to modify the direction of the incident light 108 toward the plant. For example, the light conversion layer 106 may be designed to adjust the light emitted from the peripheral regions of the light emitting layer 104 to be directed toward the plant, while making the light emitted from the central region of the light emitting layer 104 more divergent to cover more areas of the plant, thereby resulting in significantly more efficient lighting.

[0060] In some embodiments, the light conversion layer 106 or at least some of its metasurface units 122 can be designed to adjust parameters of the light emitted from the light emitting layer 104 to optimize the lighting configuration of the plant to suit its growth requirements.

[0061] In some embodiments, the light conversion layer 106 or at least some of its metasurface units 122 can be designed to tailor the light emitted from the light emitting layer 104 in a desired direction to form areas of high or low light concentration, thereby creating hot or cold spots in the targeted illumination area. Such hot or cold spots can be created to treat damaged areas of the plant or to illuminate vulnerable parts of the plant.

[0062] 7 is a schematic exploded view of a light-emitting device 200 according to some embodiments of the present disclosure. In these embodiments, the light-emitting device 200 is similar to the light-emitting device 100 in the embodiment shown in FIGS. 3 and 4, except that the light-emitting device 200 further includes a polarization control layer 202 sandwiched between the light-emitting layer 104 and the light conversion layer 106.

[0063] Moreover, in these embodiments, the light conversion layer 106 may be polarization selective. In particular, each Metasurface unit 122 may select a particular polarization, i.e., allow only light of a particular polarization state to pass through the Metasurface unit 122 and block light of other polarization states. Different Metasurface units 122 of the light conversion layer 106 may have the same or different polarization selection settings, depending on the implementation.

[0064] Polarization control layer 202 is made of a suitable material that polarizes incident light (represented in FIG. 7 by circular arrows 204 and 206) as the incident light travels through polarization control layer 202. In some embodiments, polarization control layer 202 may form a single polarization control unit to polarize incident light to a predetermined polarization state.

[0065] In some other embodiments, the polarization control layer 202 may include liquid crystals that form a single polarization control unit and have a voltage-controlled retardation. Thus, the polarization of the polarization control layer 202 may be controlled by adjusting the voltage applied to the polarization control layer 202.

[0066] In yet some other embodiments, the polarization control layer 202 may include a plurality of polarization control units (not shown) corresponding to the plurality of metasurface units 122 of the light conversion layer 106. At least some of the polarization control units may be made of liquid crystals, and the polarization thereof may be controllable by adjusting the voltage applied to the polarization control units.

[0067] Thus, the light conversion layer 106 exhibits selective response to light of different polarization states. In some embodiments, the light emitting device 200 can be used as a display that can rapidly switch between displaying different images without having to adjust the light source (e.g., the light emitting layer 102). The switching display or illumination patterns can be encoded into the polarization pattern and / or voltage pattern of the light conversion layer 106 for automatic pattern switching.

[0068] For example, in some embodiments, the light emitting device 200 may be used as a display, and the polarization control layer 202 and its light conversion layer 106 may each include a number of units forming corresponding pixels 232 and 234 (see Figures 8A-10B), each pixel including one or more subpixels.

[0069] 8A and 8B, each pixel 232 of the polarization control layer 202 includes multiple subpixels (e.g., two subpixels 242A and 242B). Thus, the polarization control layer 202 includes multiple subpixel sets (also identified with reference numerals 242A and 242B), each set including a respective subpixel 242A or 242B of each pixel 232. Each subpixel set is configured for a particular polarization setting (see FIG. 8A).

[0070] As shown in FIG. 8B, each pixel 234 of the light conversion layer 106 has one metasurface subpixel (also represented with reference number 234) that is controlled to switch between two polarization selection and phase conversion settings (shown as 246).

[0071] In operation, the light-emitting layer 104 emits light (not shown). In a preferred polarization setting, each sub-pixel set of the polarization control layer 202 modulates the light emitted from the light-emitting layer 104 to form two light beams (not shown) with different polarization states. The two light beams are superimposed and enter the light conversion layer 106.

[0072] The Metasurface subpixels 234 of the light conversion layer 106 are controlled to switch between two polarization selection and phase conversion settings 246, with a first polarization selection setting suitable for allowing the light beam from the first subpixel set 242A to pass through the Metasurface subpixels 234 and a second polarization selection setting suitable for allowing the light beam from the second subpixel set 242B to pass through the Metasurface subpixels 234. As a result, the light emitting device 200 alternately displays two images 222 and 224 (see FIGS. 11A and 11B) in two directions. Depending on the phase conversion settings, the two directions can be two different directions as shown in FIGS. 11A and 11B, or can be the same direction.

[0073] The switching of the polarization selection and phase conversion settings of the light conversion layer 106 (also called the refresh rate) can be slow or infrequent, so as to clearly alternate between the two images 222 and 224, such as displaying the first image 222 in a first position for a few seconds, and then displaying the second image 224 in a second position for a few more seconds (FIGS. 11A and 11B). Alternatively, the refresh rate of the light conversion layer 106 can be high frequency (e.g., 60 frames per second or higher) so that the two images 222 and 224 are effectively displayed simultaneously to the human eye in two positions (see FIG. 12).

[0074] In one embodiment as shown in Figures 9A and 9B, each pixel 232 of the polarization control layer 202 has one metasurface subpixel (also represented with reference number 232) that is controlled to switch between two polarization settings (see Figure 9A and shown as 248).

[0075] 9B, each pixel 234 of the light conversion layer 106 includes multiple subpixels (e.g., two subpixels 244A and 244B). Thus, the light conversion layer 106 includes multiple subpixel sets (also identified with reference numerals 244A and 244B), each set including a respective subpixel 244A or 244B of each pixel 234. Each subpixel set is configured for a particular polarization selection and phase conversion setting.

[0076] In operation, the light-emitting layer 104 emits light (not shown). The polarization control layer 202 conditions the light emitted from the light-emitting layer 104 to pass through the first sub-pixel set 244A of the light conversion layer 106 or pass through the second sub-pixel set 244B of the light conversion layer 106 to form a light beam (not shown) with a switched polarization state. Depending on the refresh rate of the light conversion layer 106, the light-emitting device 200 can alternately display two images 222 and 224 at two positions clearly or effectively simultaneously to the human eye (see FIG. 11A, FIG. 11B, and FIG. 12).

[0077] 10A and 10B, each pixel 232 of the polarization control layer 202 includes multiple subpixels (e.g., two subpixels 242A and 242B). Thus, the polarization control layer 202 includes multiple subpixel sets (also identified with reference numerals 242A and 242B), each set including a respective subpixel 242A or 242B of each pixel 232. Each subpixel set is configured for a particular polarization setting (see FIG. 10A).

[0078] Correspondingly, as shown in FIG. 10B, each pixel 234 of the light conversion layer 106 includes multiple subpixels (e.g., two subpixels 244A and 244B). Thus, the light conversion layer 106 includes multiple subpixel sets (also identified with reference numbers 244A and 244B), each set including a respective subpixel 244A or 244B of each pixel 234. Each subpixel set is configured for a particular polarization selection and phase conversion setting. The polarization selection setting of each subpixel set 244A or 244B matches the polarization setting of each subpixel set 242A or 242B (i.e., allows light from the corresponding subpixel 242A or 242B to pass through).

[0079] In operation, the light-emitting layer 104 emits light (not shown). Each sub-pixel set 242A or 242B of the polarization control layer 202 modulates the light emitted from the light-emitting layer 104 to form two light beams (not shown) with different polarization states. The two light beams are superimposed and enter the light conversion layer 106. Each light beam from the polarization control layer 202 passes through a corresponding sub-pixel set 244A or 244B of the light conversion layer 106, thereby simultaneously forming two images 222 and 224 in two directions (see FIG. 12 ).

[0080] In some embodiments, the light emitting device 200 may be used as a lighting device that can rapidly switch between different lighting patterns. Moreover, the light emitting device 200 may be used as a grow light device with a customized polarization pattern that adapts to plants with high order components that are sensitive to light polarization. For example, some plants may absorb or reflect light with a certain polarization state significantly more efficiently than light with other polarization states. Therefore, the light emitting device 200 may be used as a grow light device with a customized polarization pattern that adapts to the requirements of plants to optimize the photosynthetic process of the plants. The structure of the lighting device 200 in various embodiments may be similar to that shown in FIG. 8A-FIG. 10B.

[0081] By using a metasurface in the light conversion layer 106, the lighting device disclosed herein can efficiently couple light energy to a fiber optic cable. For example, FIG. 13 is a schematic exploded view of a light emitting device 300 according to some embodiments of the present disclosure. In these embodiments, the light emitting device 300 is similar to the light emitting device 100 in the embodiment shown in FIG. 3 and FIG. 4, and further includes a plurality of fiber optic cables 302 adjacent to each metasurface unit 122. Each metasurface unit 122 is configured to form a converging light beam that is incident on a corresponding fiber optic cable 302. Such a lighting device 300 can be used in various applications such as efficient indoor lighting, locally optimized plant lighting, and efficient light energy distribution over a target area.

[0082] In the embodiment shown in FIG. 13, light emitting device 300 is similar to light emitting device 100 (i.e., having three layers 102, 104, and 106), however, in some embodiments, light emitting device 300 may be similar to light emitting device 200 (i.e., having four layers 102, 104, 202, and 106).

[0083] In the above embodiments, the lighting device 100, 200 or 300 includes only one light conversion layer 106. In some embodiments, the lighting device may include multiple light conversion layers 106. In some embodiments, at least some of the multiple light conversion layers 106 may be polarization selective, and different light conversion layers 106 may have the same or different polarization selection settings, depending on the implementation.

[0084] As explained above, the various layers of the light emitting device 100, such as the light conversion layer 106, may be printed onto the substrate 102 or onto each other using any suitable printing technique.

[0085] For example, FIG. 14 is a conceptual diagram illustrating the printing of several layers, such as light conversion layer 106, light emitting layer 104, etc., in some embodiments.

[0086] As shown, the substrate 102 (with the emissive layer 104 printed or otherwise bonded thereto) is placed on a flat surface of a platform 342. A printing device (not shown) with a slot die head 344 is used to print the sublayers / layers. The slot die head 344 includes ink cartridges 346 filled with respective "inks" and moves (indicated by arrow 348) over the substrate 102 (or specifically the printed emissive layer 104) to deposit the Metasurface material from the ink cartridges 346 onto the substrate 102 (or the emissive layer 104) to form one or more Metasurface light-conversion units 122.

[0087] As used herein, "ink" refers to the sublayer / layer material in a suitable form such as a solution, gel or powder that is used as a precursor for the fabrication of a layer. During the slot die fabrication of each layer, a heat treatment is typically used to evaporate the solvent or melt the powder to solidify the fabricated layer.

[0088] 15 is a schematic diagram of a lighting system 400 for promoting the growth of one or more plants 410, according to some embodiments of the present disclosure. As shown, the system 400 includes a power source 402 that provides power to a control circuit 404, and a light emitting device 406, which may be any of the light emitting devices 100, 200 or 300 described above. The control circuit 404 controls the light emitting device 406 to emit light 408 having customization parameters to illuminate the plant 410 and promote the growth of the plant 410.

[0089] 16 is a schematic diagram of a lighting system 500 for promoting plant growth, according to some embodiments of the present disclosure. The lighting system 500 in these embodiments is similar to the lighting system 400 shown in FIG. 14, and further includes a sensor 412 for monitoring the growth of the plant 410, such as a light sensor for monitoring light 414 reflected from the plant 410, and provides feedback to the control circuitry 404 for adjusting the light parameters as described above to optimize the lighting configuration to better promote the growth of the plant 410.

[0090] In some embodiments, the light-emitting layer 104 may be a transparent LED layer, and the light-emitting device 100, 200, or 300 may further include a solar cell layer on the "backside" of the light-emitting layer 104 (i.e., between the substrate 102 and the light-emitting layer 104) having one or more photovoltaic cells (also called "solar cells") for converting light energy into electrical energy, and a power conversion layer on the backside of the solar cell layer. Details of the solar cell layer and the power conversion layer are described in applicant's co-pending U.S. Provisional Patent Application No. 62 / 831,828, entitled "HYBRID-ENERGY APPARATUS, SYSTEM, AND METHOD THEREFOR," the contents of which are incorporated herein by reference in their entirety.

[0091] For example, Figure 17 shows an example of a solar cell layer 540 including multiple sublayers. As shown, the solar cell layer 500 in this example includes an anode sublayer 542 made of a suitable material such as indium tin oxide (ITO), a zinc oxide (ZnO) sublayer 544, a poly(ethyleneimine) and ethoxylated poly(ethyleneimine) (i.e., PEIE) sublayer 546, an organic solar cell sublayer 548, such as a polymer solar cell sublayer, such as a bulk heterojunction (BHJ) sublayer, a molybdenum trioxide (MoO3) sublayer 550, and a cathode sublayer 552 made of a suitable material, such as silver (Ag) or aluminum (Al). The anode 542 and the cathode 552 are electrically connected to other layers, such as a power converter layer.

[0092] Pattern-controlled lighting system 18 shows a lighting device 600 in some embodiments used as an illumination source or light source with controlled illumination patterns due to precise control of the light deflection angle using metasurfaces or other light control structures. Illumination from the lighting system 600 is distributed according to a specific pattern onto an image plane 612 in which one or more objects, such as one or more plants, are located.

[0093] For ease of annotation, axes x and y represent orthogonal axes defining the image plane 612, the z-axis is an axis along the controllable illumination structure 100 and the image plane 612 and is orthogonal to axes x and y (i.e. orthogonal to the image plane 612), the y-deflection angle θ is the angle between the y-axis and the projection of the light beam 610 on the image plane 612, and the z-deflection angle φ is the angle between the z-axis and the projection of the light beam 610 on the xz plane.

[0094] Light emitting device 600 is similar to light emitting device 100 shown in Figure 4 and includes a light emitting layer 104 having one or more LEDs (not shown) and a light conversion layer 106, such as a topocentric vector control panel (TVCP) layer in these embodiments, in front of the light emitting layer 104. Although not shown in Figure 18, light emitting device 600 may also include a substrate 102 (similar to light emitting device 100 shown in Figure 4) for supporting the light emitting layer 104.

[0095] The light emitting layer 104 includes an array of LEDs as a light source, which emits a number of light beams 610 through the TVCP 106 towards an image plane 612 .

[0096] The TVCP 106 includes one or more light-conversion units 122 (also referred to as "lenses" in these embodiments, not shown in FIG. 18 ) arranged in a predetermined pattern, where each light-conversion unit 122 includes a metasurface. Each light-conversion unit 122 of the TVCP 106 controls the direction of the light beam 610 passing through the light-conversion unit 122 by controlling the deflection angles θ and φ of the light beam 610 to adjust the azimuth, elevation and angle of the light cone 610 in the image plane 612.

[0097] The TVCP 106 effectively destroys the symmetry of the light distribution that would otherwise be present on the image plane 612 (see FIG. 2). Moreover, slight changes in the deflection angles θ and φ will result in significant changes in the light intensity distribution on the image plane 612. Therefore, with a carefully constructed TVCP 106, the illumination system 600 can generate almost any light intensity distribution within a target illumination area on the image plane 612 as needed, using multiple light beams emitted from the light-emitting layer 104 through the TVCP 106 toward multiple predetermined incidence points distributed on the image plane 612.

[0098] The illumination pattern (e.g., size and shape of the target illumination area and light intensity distribution within the target illumination area) and the number of light sources (e.g., LEDs) determine the location of the predetermined incident points, which can be calculated using a suitable optimization method that optimizes a suitable cost function under the constraint that all incident points must be located within the target illumination area.

[0099] For example, to obtain a uniformly distributed (or more precisely, nearly uniformly distributed) light intensity distribution, the normalized mean square error (NMSE) of the light intensity distribution is calculated as

number

[0100] 19 illustrates the formation of a cost function in one example where a uniform illumination pattern is produced within a circular target illumination area 622 on the image plane 612. Those skilled in the art will recognize that cost functions for other illumination patterns may be similarly formed.

[0101] In the example shown in FIG. 19, the illumination system 600 may use eight light beams emitted toward respective incident points 624 distributed at uniform angular intervals on two concentric circles 626A and 626B (four points on each circle) within a circular region 622 of the image plane 612.

[0102] Any suitable optimization method, such as an artificial intelligence (AI) algorithm, a machine learning algorithm, a gradient descent (GD) method, and / or a simulated annealing (SA) method, may be used to find the global (or near-global) minimum of the NMSE in equation (1) and the corresponding deflection angles θ and φ of each light beam 610.

[0103] FIG. 20 illustrates the optimization of the following given parameters: The number of LEDs in the light-emitting layer 104; - The direction and angular spread of the field of view (FOV) of each LED, The shape of the target illumination area on the image plane 612; - the size of the target illumination area, the distance between the radiation source and the target illumination area, · The learning rate of GD, and Maximum number of iterations 6 is a flowchart showing steps of a process 640 for finding the global (or near-global) minimum of the NMSE of equation (1) using the GD method using

[0104] Those skilled in the art will recognize that the parameters discussed above may be customized by a user prior to initiation of process 640 or may be determined by setup of system 600 .

[0105] As shown in FIG. 20, after process 640 begins (step 642), the parameters described above are taken (step 644), and an initial state for each light beam 610 (e.g., an initial set of values ​​for the state variables (θ, φ)) is randomly selected (step 646).

[0106] In step 648, the gradient of the cost function at the current state is calculated for the state variables (θ, φ) of all light beams 610. The state variables (θ, φ) of all light beams 610 are then "moved" (i.e., the values ​​of the state variables (θ, φ) are changed) in the opposite direction of the gradient value of the current state multiplied by the learning rate (step 650).

[0107] In step 652, process 640 checks whether the number of iterations has reached a maximum number of iterations (predefined by the system or by the user). If the number of iterations has reached the maximum number of iterations, the optimization is complete and then process 640 ends (step 654).

[0108] In step 652, if the number of iterations has not reached the maximum number of iterations, the process 640 proceeds to step 656 to check whether the incidence point of any light beam 610 is outside the target illumination area. If not, the process 640 returns to step 648 to further "move" the state variables (θ, φ) of the light beam 610.

[0109] In step 656, if the incidence point of one or more of the light beams 610 is found to be outside the target illumination area, the process 640 recalculates the values ​​of the state variables (θ, φ) of one or more of the light beams 610 to position the incidence point of the light beam 610 at the boundary of the target illumination area along the reverse direction of the gradient value, and defines the one or more light beams as fixed beams (i.e., the state variables (θ, φ) of the light beam are no longer used in the optimization) (step 658). The process 640 then randomly selects an initial state (e.g., a set of initial values ​​of the state variables (θ, φ)) for each of the remaining light beams 610 (step 660) and returns to step 648 for further optimization.

[0110] The process 640 may loop through the steps described above one or more times, eventually stopping the attempts according to the maximum number of iterations until a global (or near-global) minimum of the NMSE is achieved. The corresponding values ​​of the state variables (θ, φ) of each light beam 610 are then used to configure the light transformation unit 122 of the TVCP 106.

[0111] In some embodiments, the optimization process may divide the light beams into multiple groups. For example, in the example shown in Figure 19, the optimization process may divide the light beams into two groups, each group containing four light beams whose incidence points are within circle 626A or 626B. The optimization process may then form a cost function whose control variables for minimizing the NMSE are the radii of gyration and the degrees of gyration of circles 626A and 626B.

[0112] 21 to 25 show optimization results using the GD method for creating uniform light intensity distribution within target illumination areas of different shapes on the image plane, including a triangular illumination area (FIG. 21), a square illumination area (FIG. 22), a pentagonal illumination area (FIG. 23), a circular illumination area (FIG. 24), and a donut- or ring-shaped illumination area (FIG. 25).

[0113] Fabrication techniques for metasurfaces The metasurface-based TVCP 106 can be fabricated using any suitable method, such as electron beam lithography. However, this technique is costly and time-consuming, and is only suitable for fabricating small metasurfaces. Because the TVCP 106 described above typically requires metasurfaces with centimeter-scale diameters, traditional electron beam lithography techniques may not be rapid and cost-effective.

[0114] In some embodiments, deep ultraviolet (UV) lithography techniques are used to fabricate metasurfaces, such as the metasurface-based TVCP 106 described above. Deep UV lithography techniques are well-established techniques used in the semiconductor field, but to the applicant's knowledge, have not been used to fabricate metasurfaces.

[0115] In this technique, a chromium layer is deposited on a glass wafer. The wafer is then spin-coated with resist, followed by UV exposure and development. Finally, the metasurface pattern is defined by etching the chromium layer. Such a technique allows the fabrication of multiple metasurfaces on a large wafer through a single process, thereby resulting in rapid and cost-effective fabrication. Moreover, deep-ultraviolet lithography techniques also allow the fabrication of metasurfaces for the visible and infrared wavelength ranges using silica, titanium dioxide or amorphous silicon.

[0116] Illumination system having a uniform illumination pattern - Patents.com As explained above, conventional lighting systems, such as LED panels used for indoor plant growth, typically do not provide uniform light distribution across the plants.

[0117] In some embodiments similar to those shown in Figures 4 and 18, uniform or near-uniform illumination of an illumination system 700, such as a grow light system, can be obtained by overlaying an angle-control light conversion layer 106, such as a TVCP layer, in front of the light-emitting layer 104. As shown in Figure 26, the light-emitting layer 104 emits a number of light beams 702 that pass through the TVCP 106 toward an image plane (not shown). The spatial distribution of each light beam 702 can be characterized by angles β, θ, and φ, where angle β determines the angular spread of the light beam 702 and angles θ and φ determine the direction of the light beam 702.

[0118] The TVCP 106 includes one or more light-conversion units 122 arranged in a predetermined pattern, with each light-conversion unit 122 including a metasurface. Each light-conversion unit 122 of the TVCP 106 is configured to precisely control the angles β, θ, and φ of the corresponding light beam 702 to arbitrarily change the angular range, altitude, and latitude of the light cone in the image plane. The TVCP 106 effectively destroys the symmetry of the light distribution that would otherwise exist in the image plane (see, for example, FIG. 2). The use of the TVCP 106 is advantageous in that slight changes in the angles β, θ, and / or φ can result in significant differences in the intensity distribution in the image plane. Thus, almost any arbitrary intensity distribution can be generated.

[0119] The illumination system 700 can be used to generate a uniform illumination pattern at an image plane and can be used as a grow light. Note that for ease of fabrication and implementation, the number of metasurfaces with different designs should be minimized.

[0120] In some embodiments, the TVCP 106 of the uniform illumination system 700 may include only two types of metasurfaces, including a set of split metasurfaces and a set of converging metasurfaces.

[0121] A split metasurface is a polarization-sensitive metasurface that modifies the angles β, θ, φ of a light beam by directing light of two orthogonal polarization states in opposite directions. In these embodiments, the light-emitting layer 104 (e.g., an LED light-emitting layer) emits unpolarized light, ensuring that the power is split equally in the two opposite directions in the split metasurface.

[0122] As shown in FIG. 27A, split metasurfaces 122A and 122B of TVCP 106 are configured to distribute light beams 702A and 702B, respectively, to the boundaries of a desired illumination pattern on an image plane (not shown).

[0123] FIG. 27B shows an illumination pattern 704A on the image plane with light energy significantly distributed along the vertical boundaries (hereinafter, the directional light is referred to as “vertical boundary focused light”) created by using a split metasurface to split the light from the emitting layer and direct the light vertically to the corresponding boundaries.

[0124] Similarly, FIG. 27C shows an illumination pattern 704B on the image plane with significantly distributed light energy along the horizontal boundaries (hereinafter, the directional light is referred to as “horizontal boundary focused light”) created by using a split metasurface rotated 90° to split the light from the emitting layer and direct the light horizontally to the corresponding boundaries (similar to the split metasurface used in FIG. 27B, but with a light energy distribution rotated 90°).

[0125] Horizontal / vertical boundary focused light as shown in FIG. 27B can be directed to the same target area on the image plane such that the directed light overlaps to form an illumination pattern 706 having light energy substantially concentrated along the four boundaries of the area (see conceptual diagram in FIG. 28).

[0126] 29A and 29B, the converging metasurface 122C is configured to modify the angle β of the light beam 702C without changing the direction of the cone of the light beam 702C. Thus, the converging metasurface 122C distributes the light beam 702C to the center of a target area on the image plane, thereby creating an illumination pattern with optical energy substantially focused at the center of the target area.

[0127] As illustrated by the conceptual diagram shown in FIG. 30, by using split metasurfaces 122A and 122B and converging metasurface 122C to direct light beams to the same target area, illumination patterns 706 (which is a combination of illumination patterns 704A and 704B shown in FIG. 28) and 708 can be combined to obtain a uniform light distribution within the target area.

[0128] Such a uniform light distribution is substantially independent of the distance between the metasurface-based TVCP 106 and the image plane 712. As shown in Figure 31, the light distribution is simply scaled different distances apart without compromising the uniformity of the distribution.

[0129] 32 shows an example implementation of a TVCP 106 using an array of metasurfaces 122. For ease of illustration, only two metasurfaces 122 are shown.

[0130] In these embodiments, the TVCP 106 includes a metasurface housing 722 that covers the LEDs 110 mounted on a printed circuit board (PCB) 724 of the light-emitting layer 104. The metasurface housing 722 includes a number of receivers 726 at locations corresponding to the LEDs 110. Each receiver 726 includes an outwardly flaring inner surface having an inner opening for receiving light emitted from the light-emitting layer 104 and an outer opening for passing the received light, the outer opening having an area larger than the area of ​​the inner opening.

[0131] In these embodiments, the inner surface of the receiver 726 is reflective to reflect light rays (emitted from the LEDs 110 within the receiver 726) at high angles to contribute to the overall illumination, thereby increasing the efficiency of the overall illumination. Maximum light throughput is achieved when the cross section of the inner surface is parabolic in shape and the LED is located at the center of the inner surface. Figure 33 is a photograph showing the metasurface housing 722 bonded to the light emitting layer 104.

[0132] The multiple Metasurface units 122 are fixed or otherwise coupled to the receivers 726 of the Metasurface housing 722 using a suitable fastening means such as epoxy and / or adhesive, thereby ensuring alignment of the LEDs 110 and the Metasurface units 122.

[0133] Polarization-selective lighting Plants are often composed of components with an ordered arrangement. As a result, light absorption in plants is often sensitive to polarization. In other words, plants may absorb more light in certain polarization states than in other polarization states. Therefore, photosynthesis may be optimized with illumination of a particular polarization state.

[0134] In some embodiments, the metasurface-based light conversion layer 106 of the growth light disclosed herein may be polarization selective, which may be implemented by arranging the metasurface nanoscale structures 124 to have an asymmetric base shape 732 as shown in FIG. 34. Thus, a growth light with such a metasurface-based light conversion layer 106 may be used to illuminate a plant with light of a specific polarization state to optimize the light for photosynthesis. In general, the metasurface of the light conversion layer 106 may be designed to illuminate a plant with various polarization states, including linear, circular, and generally elliptical polarization states. Linearly polarized illumination may be used to optimize photosynthesis in plants made of fibers oriented in a specific direction, and circularly polarized illumination may be used to optimize photosynthesis in plants made of components with a helical structure.

[0135] Metasurface-based TVCP for photovoltaic cells While always desirable in solar cells, complete light absorption by the photovoltaic cells of a solar cell is difficult to achieve due to the mismatch between the spectrum of the incident light and the spectral response of the photovoltaic cell. As shown in Figure 35, light reflection 842 occurring at the surface of the photovoltaic cell 844 also results in the loss of solar energy that could otherwise be absorbed by the photovoltaic cell 844.

[0136] In some embodiments, the metasurface-based TVCP can be incorporated into a photovoltaic panel having, for example, one or more silicon-based and / or one or more quantum dot photovoltaic cells, where the metasurface-based TVCP can be configured to effectively direct light of specific wavelengths to the photovoltaic cells. Moreover, the metasurface-based TVCP allows for a significant reduction in the size of the photovoltaic panel.

[0137] As will be appreciated by those skilled in the art, a metasurface includes nanoscale structures. The shape and distribution of the nanoscale structures of a metasurface can be designed or otherwise configured to meet the requirements of a particular application. For example, a metasurface can be designed to pass or otherwise transmit a portion of the incident light of a target spectrum through the metasurface and completely reflect another portion of the incident light from the target spectrum.

[0138] In some embodiments shown in FIG. 36, the metasurface-based TVCP 106 may be placed, for example, on the front side of a photovoltaic panel 852 having one or more silicon-based and / or quantum dot photovoltaic cells. The metasurface-based TVCP 106 includes multiple metasurface units (not shown) having a spectral response that matches the spectral response of the photovoltaic cells. Thus, the combination of the metasurface-based TVCP 106 and the photovoltaic panel 852 is significantly more efficient than the photovoltaic panel 852 alone, since if the photovoltaic panel 852 is used alone, the spectrum that is not sufficiently absorbed may turn into heat and other undesirable effects will reduce the performance of the photovoltaic panel 852. Such an arrangement or combination is particularly important for indoor photovoltaic cells that collect light energy from artificial lighting sources such as LEDs, where the metasurface units may be designed to match the specific illumination spectrum of the light source and reject other light that cannot be efficiently absorbed by the photovoltaic cells.

[0139] Another important application of metasurfaces is the above-described ability to redirect light rays. As shown in Fig. 37, the metasurface-based TVCP 106 on the front side can be a photovoltaic panel 852 configured to focus the incident light rays 854 on a small area of ​​the photovoltaic panel 852, thus allowing the size of the photovoltaic panel 852 to be significantly reduced. Fig. 38 shows a prior art photovoltaic panel 844 without the metasurface-based TVCP 106 for comparison.

[0140] Super-directional screen using metasurfaces A conventional screen or display usually has a wide angular spread of its field of view (FOV). However, in some applications it may be desirable to limit the FOV of the display.

[0141] As used herein, the term FOV refers to the angular extent of (e.g., cone-shaped or other shaped) illumination emitted from a component (e.g., an LED layer, a metasurface layer, etc.), which in various embodiments may be used for illumination or to display one or more images. The FOV may be characterized by the direction and three-dimensional (3D) angular spread of the light emitted from the component.

[0142] For example, displays in vehicles or airplanes are generally viewed only by individuals. However, as shown in FIG. 39, a display 862 with a wide FOV 868 (i.e., FOV 868 with a wide angular spread) in a vehicle or airplane (not shown) may unnecessarily emit light into the surrounding area, resulting in reduced brightness to a user 864 in front of the display 862, wasting light energy, and disturbing a person 866 adjacent to the user 864.

[0143] Similarly, a wide FOV display used in a home or theater will illuminate surrounding areas such as walls and ceilings, resulting in reduced brightness to a user in front of the display and wasting light energy.

[0144] Furthermore, in some applications requiring enhanced security or privacy, such as ATM displays, displays in banks, displays on laptops used by users for sensitive tasks, etc., displays with high directionality may be required, as wide FOV displays in these applications may pose security or privacy risks in addition to the brightness reduction issues discussed above, wasting light energy and / or disturbing nearby persons.

[0145] 40 shows a metasurface-based ultradirectional screen or display 870 according to some embodiments of the present disclosure. The ultradirectional screen 870 includes a display or display layer 872 and a metasurface panel or layer 874 on its front side.

[0146] Similar to the light conversion layer 106 described above, the metasurface panel 874 includes a plurality of metasurface units constructed from an array of nanoscale structures that direct light emitted from the display 872 in a desired direction to confine the light to within a predetermined FOV 878 that is smaller than the FOV 876 of the display 872, thereby creating a virtual visual barrier so that only the subject 864 can see the content shown on the display 872.

[0147] This Super Directional Screen 870 is Superior brightness due to concentrated distribution of light energy over a smaller area, Improved power efficiency due to avoidance of illumination of non-target areas and uniform distribution of light energy to the targeted areas; and Enhanced security and privacy as visual information is only visible to subjects in front of the superdirectional screen 870 The present invention has many advantages, including:

[0148] As explained above, metasurfaces can be designed to interact differently with light of different polarization states, which is achieved by fabricating the metasurface nanostructures with asymmetric shapes.

[0149] 41 illustrates a variable field of view (VFOV) screen or display 880 in some embodiments. The MFOV display 880 includes a display 872, a polarization control panel 884 in front of the display 872, and a polarization-sensitive metasurface panel 886 in front of the polarization control panel 884.

[0150] In these embodiments, the polarization control panel 884 may be implemented using a liquid crystal polarization rotator and is controlled by an adjustable control signal V to control the polarization of the light emitted from the display 872 to one of two orthogonal polarization states.

[0151] MFOV display 880 is similar to light emitting device or display 200 shown in Figures 11A and 11B, however, MFOV display 880 in these embodiments does not direct light of different polarization states into different directional FOVs as light emitting device or display 200 shown in Figures 11A and 11B does. Rather, polarization-sensitive metasurface panel 886 in these embodiments interacts with the polarized light to direct light in a first polarization state into a first FOV having a first angular spread 888 and light in a second polarization state to form a second FOV having a second angular spread 890. For example, first angular spread 888 may be a wide angular spread suitable for multiple users 864 and 866 of MFOV display 880 to view the displayed content, and second angular spread 890 may be a narrower angular spread than first angular spread 888 to only allow user 864 to view the displayed content.

[0152] In the above embodiment, the polarization control panel 884 polarizes all light passing through it to a first polarization state when the control signal is at a first voltage, and polarizes all light passing through it to a second polarization state when the control signal is at a second voltage. In this manner, the user 864 may switch the FOV of the MFOV display 880 between a first and a second angular spread for sharing the displayed content with an adjacent person and for creating a virtual visual barrier to prevent others from viewing the displayed content, respectively.

[0153] In another embodiment shown in Figure 42, a MFOV display 880 is similar to the displays described in Figures 10A and 10B. Specifically, the display 872 includes two sets of units (pixels or sub-pixels, depending on the design), where each set of units can be used to display an image.

[0154] Correspondingly, polarization control panel 884 and polarization-sensitive Metasurface panel 886 also each include two sets of units that correspond to the two sets of units of display 872. Each set of units of polarization control panel 884 is controlled by a separate control signal V1 or V2, and each set of units of polarization-sensitive Metasurface panel 886 corresponds to a particular polarization state and directs light of that polarization state to a particular FOV.

[0155] Thus, the display 872 may simultaneously display two images using two sets of pixels / units, and the polarization control panel 884 polarizes the light of the first and second images into a first and second polarization state. The polarization-sensitive metasurface panel 886 then directs the light in the first polarization state (i.e., the first image) into a first FOV with a wide angular spread for sharing the first image with multiple people 864 and 866, and directs the light in the second polarization state into a second FOV with a narrow angular spread for preventing person 866 from viewing the second image.

[0156] For example, as shown in Figures 43A and 43B, the display simultaneously displays two images 892A and 892B, where image 892A is displayed within a first FOV with a wide angular spread and image 892B is displayed within a second FOV with a narrow angular spread.

[0157] As shown in FIG. 43C, display 872 divides the pixels into a first set of pixels 894A and a second set of pixels 894B arranged side-by-side for displaying images 892A and 892B simultaneously and side-by-side.

[0158] As shown in FIG. 43D, the polarization control panel 884 includes a plurality of polarization units 894 corresponding to pixels of the display 872, with a first set of polarization units 896A corresponding to a first set of pixels 894A for polarizing light passing therethrough into a first polarization state, and a second set of polarization units 896B corresponding to a second set of pixels 894B for polarizing light passing therethrough into a second polarization state.

[0159] As shown in FIG. 43E, the polarization-sensing metasurface panel 886 includes a plurality of metasurface units 898 that correspond to the polarization units 894 of the polarization control panel 884, and that direct light in a first polarization state passing through the metasurface units 898 to a first FOV (having a wide angular spread) and direct light in a second polarization state passing through the metasurface units 898 to a second FOV (having a narrow angular spread).

[0160] As a result, a first image 892A is directed to the first FOV, and a second image 892B is directed to the second FOV. As shown in FIG. 43F, images 892A and 892B are visible to a user 864 located in both the first FOV and the second FOV, while a user 866 located only in the first FOV (which has a wide angular spread) can only see the first image 892A. In other words, image 892B is not visible to a user 866 located only in the first FOV.

[0161] Three-dimensional (3D) displays using metasurfaces FIG. 44 illustrates a metasurface-based 3D display 900 according to some embodiments of the present disclosure. As illustrated, the 3D display 900 includes a display 872 and a polarization-sensitive metasurface panel 886 in front of the display 872. The display 872 displays an image by emitting unpolarized light (generally including both polarization states). The polarization-sensitive metasurface panel 886 is configured to direct light in a first polarization state to a first FOV 888 and direct light in a second polarization state to a second FOV 890 slightly offset laterally from the first FOV 888. A user 864 wearing glasses with lenses that polarize to different polarization states sees a first image with one eye and a second image with the other eye, where the second image has a slight perspective distortion from the first image, thereby generating a 3D perception of the displayed image.

[0162] In some embodiments, the 3D display 900 may also include a polarization control panel 884 sandwiched between the display 872 and a polarization-sensitive metasurface panel 886. The polarization control panel 884 alternately polarizes light from the display 872 between a first polarization state and a second polarization state during operation.

[0163] FIG. 45 illustrates a metasurface-based 3D display 920 according to some embodiments of the present disclosure. The 3D display 920 is similar to that illustrated in FIG. 44. However, a polarization-sensitive metasurface panel 886 is configured to direct light in a first polarization state to a first FOV 888 that covers only a first eye of a user 864, and to direct light in a second polarization state to a second FOV 890 that covers only a second eye of the user 864. Thus, a user 864 not wearing glasses with polarized lenses may see a first image with one eye and a second image with the other eye, with the second image having a slight perspective distortion from the first image, thereby creating a 3D perception of the displayed image.

[0164] In some embodiments, the 3D display 920 may also include a polarization control panel 884 sandwiched between the display 872 and a polarization-sensitive metasurface panel 886. The polarization control panel 884 alternately polarizes light from the display 872 between a first polarization state and a second polarization state during operation.

[0165] Solar cell angle correction In the prior art, solar panels may face the problem of solar reflection.

[0166] As one skilled in the art will appreciate, the angle of incidence of sunlight can have a significant effect on the efficiency of a photovoltaic cell. As shown in Figure 46, the photovoltaic cells of a solar panel 942 are most efficient when sunlight 944 strikes the photovoltaic cells perpendicularly.

[0167] As shown in Figure 47, at different times when sunlight 944 is at a non-perpendicular angle to the photovoltaic cells of the solar panel 942, some of the sunlight 946 is reflected, reducing the efficiency of the photovoltaic cells. Thus, the photovoltaic cells of a fixed solar panel will have different efficiencies at different times of the day and on different days of the year. Although solar tracking systems have been used to improve the efficiency of photovoltaic panels by rotating the solar panel to track the sun, such systems require a tracking system and moving parts, making them expensive to manufacture and use.

[0168] 48 and 49 show a solar energy collecting device 970 including a solar panel 972 having one or more photovoltaic cells and a number of TVCPs 974 on its front side. Using polarization sensitive metasurfaces, the response of each TVCP 974 can be changed using an embedded polarization control panel, so that the multiple TVCPs 974 can change the direction of sunlight 944 incident at a predetermined range of incidence angles so that it is perpendicular to the photovoltaic cells when it strikes the solar panel 972, thereby improving efficiency without the need for a sun tracking system or moving parts.

[0169] In some embodiments described above, the lighting devices and / or systems are used for plant growth, such as indoor or outdoor plant growth. However, those skilled in the art will recognize that the lighting devices and / or systems disclosed herein may alternatively be used in other applications, such as street lighting.

[0170] Although embodiments have been described above with reference to the accompanying drawings, those skilled in the art will recognize that changes and modifications can be made without departing from the scope of the invention as defined by the appended claims.

Claims

1. 1. A light emitting device, comprising: a light-emitting layer for emitting light; a light conversion layer coupled to the light emitting layer, the light conversion layer including a plurality of light conversion units, each light conversion unit including a metasurface for adjusting one or more parameters of the light emitted from the light emitting layer; Including, the light-emitting layer includes a plurality of light-emitting units; A light emitting device, wherein the plurality of light conversion units are positioned corresponding to the positions of the plurality of light emitting units so as to align the plurality of metasurfaces with the plurality of light emitting units.

2. 10. The light emitting device of claim 1, wherein the light emitting layer comprises one or more light emitting diodes (LEDs) for emitting light.

3. The light emitting device according to claim 1 or 2, wherein the light conversion layer comprises a housing comprising a plurality of receptacles for receiving a plurality of metasurfaces.

4. 4. The light emitting device of claim 3, wherein each of the plurality of receiving portions includes an outwardly extending inner surface having an inner opening for receiving light emitted from the light emitting layer and an outer opening for passing the received light, the outer opening having an area larger than an area of ​​the inner opening.

5. The lighting device of claim 4 , wherein the inner surface of each of the plurality of receptacles is reflective.

6. The light emitting device according to claim 4 , wherein a cross section of the inner surface of each of the plurality of receiving portions has a parabolic shape.

7. 1. A light emitting device, comprising: a light-emitting layer for emitting light; a light conversion layer including a plurality of light conversion units, each light conversion unit including a metasurface, at least one metasurface being polarization selective for selectively passing the light emitted from the light emitting layer having a predetermined polarization state through the metasurface; Equipped with the light-emitting layer includes a plurality of light-emitting units; A light emitting device, wherein the plurality of light conversion units are positioned corresponding to the positions of the plurality of light emitting units so as to align the plurality of metasurfaces with the plurality of light emitting units.

8. The light emitting device of claim 7 , wherein each of the plurality of metasurfaces comprises a plurality of nanoscale structures arranged in an asymmetric base configuration.

9. 9. A light emitting device according to claim 7 or 8, further comprising a polarization control layer sandwiched between the light emitting layer and the light conversion layer for polarizing the light emitted from the light emitting layer.

10. 10. The light emitting device according to claim 7 or 9, which is a grow light for promoting the growth of one or more plants.

11. A light emitting device for promoting the growth of one or more plants, comprising: a light-emitting layer for emitting light; At least one light conversion layer including a plurality of light conversion units, each light conversion unit including a metasurface for adjusting one or more parameters of the light emitted from the light emitting layer to optimize a lighting configuration for the one or more plants; Including, the light-emitting layer includes a plurality of light-emitting units; A light emitting device, wherein the plurality of light conversion units are positioned corresponding to the positions of the plurality of light emitting units so as to align the plurality of metasurfaces with the plurality of light emitting units.

12. A display device, comprising: a light-emitting layer for emitting light; At least one light conversion layer including a plurality of light conversion units, each of which includes a metasurface for adjusting one or more parameters of the light emitted from the light emitting layer to display one or more images; Including, the light-emitting layer includes a plurality of light-emitting units; A display device, wherein the plurality of light conversion units are positioned corresponding to the positions of the plurality of light emitting units so as to align the plurality of metasurfaces with the plurality of light emitting units.

13. 1. A light emitting device, comprising: a light-emitting layer for emitting light; a polarization control layer coupled to the light emitting layer for polarizing the light emitted from the light emitting layer; at least one light conversion layer coupled to the polarization control layer, the at least one light conversion layer including a plurality of light conversion units, each light conversion unit including at least one metasurface, the at least one metasurface being polarization selective for selectively passing the polarized light from the polarization control layer through the metasurface to switch between different illumination patterns or images; Including, the light-emitting layer includes a plurality of light-emitting units; A light emitting device, wherein the plurality of light conversion units are positioned corresponding to the positions of the plurality of light emitting units so as to align the plurality of metasurfaces with the plurality of light emitting units.

14. 1. A light emitting device, comprising: a light-emitting layer for emitting light; a polarization control layer coupled to the light emitting layer for polarizing the light emitted from the light emitting layer; at least one light conversion layer coupled to the polarization control layer, the at least one light conversion layer including a plurality of light conversion units, each light conversion unit including at least one metasurface, the at least one metasurface being polarization selective for selectively passing the polarized light from the polarization control layer through the metasurface to create a plurality of different illumination patterns or images at different locations; Including, the light-emitting layer includes a plurality of light-emitting units; A light emitting device, wherein the plurality of light conversion units are positioned corresponding to the positions of the plurality of light emitting units so as to align the plurality of metasurfaces with the plurality of light emitting units.

15. 1. A light emitting device, comprising: a light emitting layer for emitting light towards a first source field of view (FOV); at least one metasurface layer in front of the light-emitting layer for directing the light emitted from the light-emitting layer towards a second FOV having an angular spread smaller than the angular spread of the first FOV; a polarization control layer sandwiched between the light emitting layer and at least one light conversion layer; Including, the polarization control layer is configured to polarize the light emitted from the light emitting layer into a first polarization state or a second polarization state in response to a control signal; a first polarization state of the light from the polarization control layer toward a second FOV having an angular spread smaller than the angular spread of the first FOV, and a second polarization state of the light from the polarization control layer toward a third FOV having an angular spread larger than the angular spread of the second FOV.

16. 1. A light emitting device, comprising: a light-emitting layer for emitting light; a light conversion layer in front of the light emitting layer, the light conversion layer including a plurality of light conversion units, each light conversion unit including a metasurface for directing light emitted from the light emitting layer toward a target area to form a predetermined light distribution pattern; Including, the light-emitting layer includes a plurality of light-emitting units; A light emitting device, wherein the plurality of light conversion units are positioned corresponding to the positions of the plurality of light emitting units so as to align the plurality of metasurfaces with the plurality of light emitting units.

17. 17. The lighting device of claim 16, wherein the predetermined light distribution pattern is a substantially uniform distribution of light energy on the target area.

18. 18. The light emitting device of claim 17, wherein the plurality of metasurfaces includes a first set of metasurfaces for directing the light emitted from the light emitting layer towards a boundary of the target area, and a second set of metasurfaces for directing the light emitted from the light emitting layer towards a center of the target area to generate the substantially uniform light energy distribution on the target area.

19. 1. A light emitting device, comprising: a light-emitting layer for emitting light; at least one metasurface layer in front of the light emitting layer for directing the light emitted from the light emitting layer in a first polarization state toward a first FOV and for directing the light emitted from the light emitting layer in a second polarization state toward a second FOV; wherein the first FOV and the second FOV are superimposed and laterally offset from each other to create a three-dimensional (3D) perception for a user wearing glasses having lenses with different polarization states.

20. 1. A light emitting device, comprising: a light-emitting layer for emitting light; at least one metasurface layer in front of the light emitting layer for directing the light emitted from the light emitting layer in a first polarization state toward a first FOV and for directing the light emitted from the light emitting layer in a second polarization state toward a second FOV; wherein the first FOV and the second FOV are laterally offset from each other such that the first FOV is visible only to a first eye of the user at a predetermined distance and the second FOV is visible only to a second eye of the user at the predetermined distance to create a 3D perception for a user.

21. A method for manufacturing a light emitting device, comprising: printing a light conversion layer onto the light emitting layer; the light-emitting layer includes a plurality of light-emitting units for emitting light; The light conversion layer includes a plurality of light conversion units, each of which includes a metasurface for adjusting one or more parameters of light emitted from the light emitting layer; The method, wherein the plurality of light conversion units are at positions corresponding to positions of the plurality of light emitting units to align the plurality of metasurfaces with the plurality of light emitting units.

Images