Pattern projection and detection using planar optics

Abstract

An optical pattern projection device includes a light emitter or array of light emitters and one or more planar optics layers configured to project and separate a light beam from the light emitter to generate a projected light pattern, the projected light pattern comprising a plurality of sub-patterns, each sub-pattern corresponds to one of the light emitters. The planar optic layer may include a single optical metasurface with superimposed beam shaping and / or projected phase profiles and beam splitting phase profiles. Alternatively, the planar optic layer may include two optical metasurfaces each containing a light shaping and / or projected phase profile, which together produce a linear relationship between the emitter position and the corresponding beam projection angle, and one or both of the metasurfaces further containing a superimposed beam separation phase profile. The light shaping and / or projected phase profile may have similar functionality as the microlens array. A structured light camera combining optical pattern projection and detection is also provided.

Description

Background Technology

[0001] This invention relates to planar optical devices and their applications in optical and photonic systems.

[0002] Optical pattern generation and detection captures changes in the intensity, phase, or polarization of light in an illuminated scene, which is crucial for applications such as 3D sensing, medical imaging, automation, lighting, displays, LiDAR (light detection and ranging), optical computing, and environmental monitoring. State-of-the-art pattern generation optics typically rely on refractive and / or diffractive optical elements (DOEs) for light shaping and projection. Such traditional optical approaches often result in complex multi-element assemblies, suboptimal pattern quality, limited field of view (less than 90°), poor efficiency, and bulky form factors.

[0003] US 20210044748 describes an optical system (see Figures 13A and 13B) in which a superlens is used to modulate a beam of light emitted by an array of emitters to generate 2D or 3D optical patterns, dot arrays or point clouds, images, holograms or patterns with different polarization and / or spectral properties. Summary of the Invention

[0004] The present invention relates to an optical patterning architecture based on planar optics, which substantially avoids one or more of the problems caused by the limitations and drawbacks of related technologies.

[0005] Embodiments of the present invention provide light projection, patterning, and detection architectures using metasurface planar optics. Compared to conventional optical approaches, these architectures offer high performance, small form factor, and versatility. These optical architectures can be used in a variety of optical systems, including sensing, structured light imaging, illumination, displays, LiDAR, computing, etc.

[0006] Additional features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practice of the invention. The objects and other advantages of the invention will be realized and obtained by means of the structures specifically pointed out in this written description, its claims, and the accompanying drawings.

[0007] To achieve the above objectives, the present invention provides an optical pattern projection device comprising: one or more emitters; and a first optical metasurface coupled to the one or more emitters and configured to project, reshape, and / or separate a light beam generated by the one or more emitters to generate a projected light pattern. The first metasurface layer contains at least two superimposed phase profiles that perform different functions on each other, each of the at least two phase profiles being configured to modulate, collimate, focus, diverge, deflect, shape, separate, diffract, or diffuse the light beam from the one or more emitters.

[0008] In some embodiments, at least one of the at least two superimposed phase profiles is configured to separate or diffract the light so as to spatially or angularly distribute the light beams from each of the one or more emitters into multiple channels.

[0009] The device may further include a second optical metasurface spaced apart from the first optical metasurface. The second optical metasurface contains light-shaping and / or projection phase profiles configured to collimate, focus, and / or deflect light beams from the one or more emitters. The first and second optical metasurfaces cooperate to establish a defining relationship between emitter position or optical characteristics and the corresponding beam projection angle. In some embodiments, this defining relationship is a linear relationship between emitter position and beam projection angle.

[0010] In another aspect, the present invention provides an optical pattern projection device comprising: an array of light emitters including a plurality of light emitters; and one or more planar optical device layers configured to project and separate light beams generated by the plurality of light emitters to generate a projected light pattern, the projected light pattern including a plurality of sub-patterns, each sub-pattern corresponding to one of the light emitters, wherein the sub-patterns are identical in shape, displaced relative to each other in position, and overlap each other.

[0011] In another aspect, the present invention provides an optical pattern projection device comprising: an array of emitters including a plurality of emitters; and a planar optical device layer coupled to the array of emitters and configured to project, reshape, and / or separate light beams generated by the plurality of emitters to generate a projected light pattern, the projected light pattern including a plurality of sub-patterns, each sub-pattern corresponding to one of the emitters, wherein the planar optical device layer includes superimposed phase profiles including a phase profile for beam collimation and projection and a beam separation phase profile, wherein different regions of the planar optical device are configured to couple light beams from different emitters in the phase profile for beam collimation and projection, and the beam separation phase profile is configured to spatially distribute the light beam from each emitter into a plurality of channels.

[0012] In another aspect, the present invention provides an optical pattern projection device comprising: a light emitter or an array of light emitters including a plurality of light emitters; and a single planar optical device layer coupled to the light emitter or the array of light emitters and configured to project, reshape and / or separate light beams generated by the one or more light emitters to generate a projected light pattern.

[0013] In another aspect, the present invention provides an optical pattern projection device comprising: a light emitter or an array of light emitters including a plurality of light emitters; and two planar optical device layers spaced apart from each other and having the same size, configured to project, reshape and / or separate a light beam generated by the one or more light emitters to generate a projected light pattern comprising a plurality of sub-patterns, each sub-pattern corresponding to one of the light emitters.

[0014] In another aspect, the present invention provides an optical pattern projection device comprising: a light emitter or an array of light emitters including multiple light emitters; and two optical metasurfaces spaced apart from each other and configured to project, reshape, and / or separate light beams generated by the one or more light emitters to generate a projected light pattern comprising multiple sub-patterns, each sub-pattern corresponding to one of the light emitters, wherein each of the two optical metasurfaces contains a light-shaping, projection, and / or separation phase profile configured to collimate, focus, and / or deflect the light beams from the one or more light emitters, wherein the two optical metasurfaces cooperate with each other to establish a defining relationship between the position or optical characteristics of the light emitter and the projection angle of the light beam, and wherein at least one of the two optical metasurfaces further contains a superimposed beam separation phase profile configured to spatially distribute the light beams from each light emitter into multiple channels.

[0015] In another aspect, the present invention provides an optical pattern projection and detection device, which includes any of the above-mentioned optical pattern projection devices and further includes an optical pattern detection device, which includes: another optical metasurface; and a light receiver coupled to the other optical metasurface.

[0016] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory, and are intended to provide further explanation of the claimed invention. Attached Figure Description

[0017] Figures 1A to 1B Two examples of optical pattern generation architectures using planar optics according to embodiments of the present invention are illustrated schematically.

[0018] Figures 1C to 1E Three examples of light patterns generated by an optical patterning architecture according to embodiments of the present invention are shown.

[0019] Figures 2A to 2D An exemplary optical pattern generation architecture according to an embodiment of the present invention is shown, which generates optical patterns with... Figure 1C The light pattern shown is similar to the light pattern shown.

[0020] Figures 3A to 4E It shows the relationship with Figures 2A to 2D The optical pattern generation architecture shown has similar emitter arrays and dot projection characteristics to other optical pattern generation architectures.

[0021] Figures 4A to 4E It shows the relationship with Figures 2A to 2DThe optical pattern generation architecture shown is similar to another optical pattern generation architecture in terms of emitter array and dot projection characteristics.

[0022] Figures 5A to 5D An exemplary optical pattern generation architecture according to an embodiment of the present invention is shown, which generates optical patterns with... Figure 1D The light pattern shown is similar to the light pattern shown.

[0023] Figures 6A to 6E It shows the relationship with Figures 5A to 5D The optical pattern generation architecture shown is similar to another optical pattern generation architecture in terms of emitter array and dot projection characteristics.

[0024] Figures 7A to 7B An exemplary optical pattern generation architecture according to other embodiments of the present invention is shown.

[0025] Figure 8 A structured light camera, combining a pattern projector based on planar optics and an imager based on planar optics, is illustrated schematically according to an embodiment of the invention.

[0026] Figures 9A to 9D The design of a multilayer planar optical device architecture according to an embodiment of the present invention is illustrated schematically.

[0027] Figure 10A A multilayer planar optical device architecture according to another embodiment of the present invention is illustrated schematically. Figure 10B and Figure 10C It shows that they are respectively made by Figure 10A The structure and light distribution generated by a single-layer planar optical device. Detailed Implementation

[0028] Embodiments of the present invention provide optical architectures, systems, and designs for pattern projection and detection using planar optics (e.g., metasurface optics, metamaterials, subwavelength optics, etc.). Figure 1A and Figure 1B As schematically illustrated, the exemplary pattern generation system includes the following components: an emitter array 101 containing one or more emitters; and one or more planar optical elements (FO) 102 coupled to the emitter array. The planar optical elements 102 (single or multiple elements) are designed to provide beam projection, shaping, separation, and / or deflection functionality. The planar optical elements 102 can modulate the phase, intensity, and / or polarization of the beam or beam array emitted by the emitter array 101.

[0029] For example, planar optics 102 may be a metasurface containing superimposed phase profiles including light shaping and / or projection functions and beam splitting functions to generate a desired pattern. The light shaping and / or projection phase profiles may be designed to collimate, focus, and / or deflect light from the emitters (e.g., generate a dot array or pattern from the emitter array), or provide other wavefront modulation functions. The beam splitting phase profile further functions to spatially distribute the projected light into multiple channels, thereby generating, for example, multiple dot arrays or multiple projected patterns. In other examples, metasurface 102 contains two or more superimposed phase profiles that perform different functions on each other, each phase profile configured to modulate, collimate, focus, diverge, deflect, shape, split, diffract, diffuse, or otherwise modulate light from the emitter array 101.

[0030] Pattern generation optics can produce any 2D or 3D pattern, including but not limited to dot arrays, lines, matrices, letters, graphics, holograms, random patterns, grayscale patterns, uniform patterns, diffuse patterns, etc. Therefore, these pattern generation optics can be used in projectors, illuminators, diffusers, etc. Light shaping and / or projection phase profiles (e.g., acting as lenses) and beam separation phase profiles can be superimposed on the same planar optical layer. Figure 1A ) on or superimposed on separate planar optical device layers ( Figure 1B Furthermore, depending on the characteristics of the incident light (e.g., wavelength, polarization, incident angle, etc.), the superimposed phase profiles can be configured to function identically or differently. The planar optical device 102 can be configured to provide different responses to different optical characteristics.

[0031] Planar optical component 102 can be a metasurface containing one or more superimposed phase profiles. As an example, the planar optical component can be a metasurface containing a lens phase profile or a superimposed phase profile of a lens and a beam splitter. The lens phase profile can collimate and / or reshape and project light from the emitter array 101. The beam splitter phase profile further distributes the projected pattern into multiple channels; or generates multiple replicas of the projected pattern and deflects them in different directions. The beam splitter phase profile can contain sub-regions with different k-vectors (e.g., k-vectors parallel to the plane of the planar optical component, or in-plane phase gradient patterns) that distribute the incident beam and deflect it in different directions. The beam splitter phase profile can contain a phase profile similar to that of a prism and / or grating array, where each prism and / or grating deflects a portion of the incident light in a different direction (channel). The beam splitter phase profile can also be in a form similar to a grating that diffracts the incident light into different orders. The metasurface can be designed to control the power distribution between different diffraction orders.

[0032] Metasurface 102 can also be designed to be sensitive to different characteristics of incident light (e.g., polarization, wavelength, angle of incidence, etc.), so that light with different characteristics will be modulated differently, for example, redirected to different directions (channels), thereby enabling the metasurface to function as a beam splitter, diffuser, or distributor. Additional beam splitting or patterning phase profiles can be applied to each or all of the separated channels to produce additional sub-channels.

[0033] One embodiment of a lens phase profile is a quadratic phase profile. In other examples, a lens phase profile may also be defined as a polynomial expansion of spatial coordinates, a freeform surface phase profile, a discontinuous phase profile, a piecewise phase profile, a superimposed phase profile, or other forms. One or more metasurfaces or lens profiles may be used. The phase profile can be designed to control or improve the performance of an optical system, such as imaging and / or projection quality, resolution, field of view (FOV), depth of field, angle of incidence (AOI)-image height relationship, distortion, relative illumination, uniformity, efficiency, etc.

[0034] More generally, the planar optical device 102 may include, but is not limited to, subwavelength optics, metasurfaces, multilayer metasurfaces, metamaterials, diffractive optical elements (DOEs, such as binary, multilevel, or grayscale DOEs), holographic optical elements (HOEs), wafer-level optics (WLOs), micro-optics, or combinations thereof. One embodiment of the planar optical device is an optical metasurface. An optical metasurface (also alternatively referred to as a subwavelength diffractive optics) is an artificial medium comprising a 2D array of subwavelength optical structures (often called superatoms) typically positioned on a substrate. The superatoms and the substrate may be made of the same or different optical materials. The superatoms are designed to alter the phase, amplitude, and / or polarization of the incident light. The superatoms may have the same or different geometries, sizes, and orientations. Exemplary geometries may include rectangles, cylinders, freeform surfaces, or any other suitable shape or combination of different shapes. The lattice of the superatoms may have any suitable shape and period (e.g., square, rectangular, or hexagonal). The lattice can also be aperiodic, with different or random distances between adjacent superatoms. In some examples, the gaps between adjacent superatoms can be designed to have a constant gap distance.

[0035] Metasurface 102 can be planar, curved, or conformally integrated with its substrate. One or both sides of the substrate can be planar or curved. Both the metasurface and the substrate can be rigid, flexible, or stretchable. The geometry, size, and layout of the metasurface and the substrate are designed to provide the desired optical functionality. The metasurface can be designed to operate at a single wavelength, at multiple wavelengths, or over a continuous spectral range. The metasurface can be designed to provide different functionalities depending on the characteristics of the incident light (e.g., polarization, wavelength, angle of incidence, intensity, etc.). With appropriate configuration and materials, the metasurface can be designed for all optical wavelengths (e.g., UV, visible, near-infrared, mid-infrared, long-wave infrared, etc.). The metasurface can be immersed in another optical material. Additional elements (a single element or an array of elements) can also be included to modulate the light, such as filters (e.g., spectral, polarization, spatial, and / or angular filters), refractive and / or diffractive and / or reflective optical elements, light modulators, liquid crystal elements, etc.

[0036] Spacer 103, made of air, glass, polymer, semiconductor, or other optical materials, can be positioned between planar optical component 102 and emitter array 101. Emitter array 101, planar optical component 102, and spacer 103 (if present) can be mechanically coupled to each other using any suitable structure, such as adhesive.

[0037] The planar optical device architecture and design described in this disclosure can be used for both light projection (when coupled to a emitter) and detection (when coupled to a detector or receiver) (see [link to relevant documentation]). Figure 8 (This will be described in more detail later). When used for light projection, emitter 101 may include one or more light sources (e.g., lasers, light-emitting diodes (LEDs)) and / or optical channels (e.g., optical fibers, waveguides, optical couplers, etc.). When used for light detection, receiver may include one or more photodetectors and / or optical channels (e.g., optical fibers, waveguides, optical couplers, etc.). In addition to physical objects, emitters (more generally referred to as light transmitters) and receivers may also be non-physical, such as images and / or light patterns generated or received by other optical components or systems, respectively. An emitter array may include emitters configured to emit light having the same or different characteristics (e.g., wavelength, polarization, beam divergence, order, or other beam characteristics). Additional elements (a single element or an array of elements) may also be included to modulate the emitted light, such as filters (e.g., spectral, polarization, spatial, and / or angular filters), refractive and / or diffractive and / or reflective optics, light modulators, liquid crystal elements, etc. An example is a pixelated array of spectral filters or a single filter coupled to an emitter array. Another example is a pixelated polarization filter array or a single filter coupled to an emitter array.

[0038] The emitters can have the same or different geometries, sizes, and orientations. Exemplary geometries can include circles, squares, rectangles, freeform surfaces, or any other suitable shape or combination of different shapes. The emitters can be positioned with any suitable layout and spacing (e.g., squares, rectangles, or hexagons). The spacing can also be aperiodic, with different or random distances between adjacent emitters. The emitters can be positioned on planar or non-planar surfaces.

[0039] Figures 1C to 1E It shows that it can be made by Figure 1A and Figure 1B Three examples of light patterns generated by the optical pattern generation architecture are shown. Each light pattern comprises multiple sub-patterns, each generated by light from one of the emitter arrays. It should be noted that the circles, squares, and triangles in these figures are used to represent different sub-patterns, not the shape of the projected light spot. These sub-patterns are identical in shape and shifted relative to each other in position. These sub-patterns can overlap each other (e.g., ...). Figure 1C , Figure 1E ), or they may not overlap (e.g., Figure 1D ).exist Figure 1C In the illustrated light pattern, the light spots formed by the three emitters comprise an alternating array of dots; more specifically, in this example, columns 1, 4, 7... are formed by the third emitter, columns 2, 5, 8... are formed by the second emitter, and columns 3, 6, 9... are formed by the first emitter. Figure 1D In the illustrated light pattern, the light spot formed by the three emitters comprises three spatially separated dot arrays, each formed by one of the three emitters. Figure 1E In the light pattern shown, the light spots formed by the three emitters comprise staggered multi-column blocks; more specifically, in this example, the first three-column block, the fourth three-column block, the seventh three-column block... are formed by the third emitter, the second three-column block, the fifth three-column block, the eighth three-column block... are formed by the second emitter, and the third three-column block, the sixth three-column block, the ninth three-column block... are formed by the first emitter.

[0040] Examples of optical pattern generation architectures according to embodiments of the present invention are described in more detail below.

[0041] In one example ( Figures 2A to 2D In this context, planar optical devices (e.g., metasurfaces) contain a superimposed phase profile of lenses (for beam collimation and / or projection) and beam splitters to generate a phase profile consistent with... Figure 1C The pattern shown is a similar pattern of interlaced dot arrays. Figure 2AA ray tracing simulation of an ultra-compact pattern generation system design implemented with such planar optics is shown. The planar optics component collimates the light from the emitter and projects it in different directions, and further separates each beam into multiple channels (seven in this example, labeled 0 to +3), thereby producing high-density, high-quality speckle projection. Figure 2B A ray tracing simulation of a single channel (channel 0) is shown (it should also be noted that...) Figure 1C The dashed rectangle in the diagram indicates channel 0. It should be noted that... Figure 2A and Figure 2B In the middle, the most counterclockwise ray in each channel corresponds to the one located at... Figure 2A The light emitter is located at the lower end of the light emitter array 101. Figure 2C and Figure 2D Simulation results are shown indicating the diffraction-limited beam quality of a collimated beam emitted from the emitter array. In this example, the divergence angle is less than 0.13 degrees. In this example, the system is designed with a wavelength of 940 nm, but other wavelengths can also be selected.

[0042] The optical system can be configured to achieve various beam shaping functions, such as collimation, focusing, divergence, or other desired intensity and / or phase distributions of the projected pattern (e.g., dots, lines, matrices, graphics, letters, holograms, random patterns, grayscale patterns, uniform patterns, diffuse patterns, etc.). The projected optical pattern can be further engineered by controlling the position or arrangement of the emitter array and its optical characteristics (e.g., polarization, wavelength, angle of incidence, etc.). Additional optical elements (e.g., planar optics, refractive / reflective optics, microlens arrays, etc.) can be incorporated to further modify performance and / or functionality.

[0043] Figures 3A to 3E It shows the relationship with Figures 2A to 2D The design in the image exhibits point projection characteristics similar to those of other designs. (Targeting...) Figure 3A The exemplary emitter array shown is (e.g., a VCSEL (vertical cavity surface emitter laser) array). Figure 3B The diagram illustrates the far-field angular distribution of a point array projected by a single-channel projector (without beam splitting). Each emitter is collimated and projected by the projector's superoptics and corresponds to a single point in the far field. For example, when there are M emitters in the emitter array, a single-channel projector can be used to form a total of M points. The beam splitting phase profile can be superimposed on the beam projection (or lens) phase profile in a planar optics to generate multiple point arrays and direct them in different directions. For example, if the beam splitting phase profile includes N×N different wave vectors, the point array projected by the single channel will be split into N×N channels, and an N×N×M point array can be formed. Thus, each emitter corresponds to multiple projected points. Figure 3C The far-field angular distribution of a multi-channel projector with a 7×7 wave vector, generating a point array of 49 channels, is shown. Compared to the single-channel case, the FOV of the multi-channel projector is further increased (e.g., increased by a factor of 7). Therefore, in this example, a diagonal FOV (dFOV) of approximately 130° is achieved. Figure 3D It shows Figure 3C An enlarged view showing the diffraction-limited performance of a collimated beam with a total divergence angle of less than 0.13 degrees. Figure 3E The spatial intensity distribution of the projected point at an exemplary projection distance of 100 mm is shown.

[0044] By altering the characteristics of the projected beam (e.g., divergence, size, intensity pattern, etc.), patterns with different characteristics (e.g., projection distance, spot size, intensity distribution) can be generated. By controlling the position, size, density, and / or phase gradient of the overall or sub-regions of the beam separation phase profile of the planar optics, the beam separation ratio between different channels, the beam size of each channel, the projection distance, and / or deflection angle can be changed. The wave vector can also be implemented using a 1D or 2D diffraction grating type structure. The diffraction orders generated from the grating can be used for beam separation or redirection. The planar optics may or may not be positioned in direct contact with the emitter array.

[0045] By increasing the number of wave vectors (e.g., in-plane wave vectors or phase gradient patterns), the projected pattern can be further separated and deflected to increase the number of points and increase the overall field of view (FOV). For example, as Figures 4A to 4E As shown, by combining the same single-channel projection phase profile with a beam separation phase profile having 9×9 different wave vectors, the projected point array is separated into 81 channels and achieves a total dFOV of approximately 170°.

[0046] Figures 4A to 4E The point projection characteristics of this exemplary design are shown. Figure 4A An exemplary light emitter array (e.g., a VCSEL array) is shown. Figure 4B The far-field angular distribution of a dot array projected by a single-channel projector (without beam splitting) is shown. Each emitter corresponds to a single projected dot. Figure 4C The far-field angular distribution of the multi-channel projector is shown. Beam-separated phase profiles (e.g., composed of 9×9 distinct wave vectors) are superimposed on the single-channel beam projection phase profile to generate multiple point arrays (e.g., 81 channels per emitter) and direct them in different directions. Each emitter corresponds to multiple projected points. Compared to the single-channel case, the FOV of the multi-channel projector is further increased (e.g., increased by a factor of 9). A diagonal FOV of approximately 170° is achieved. Figure 4D It shows Figure 4C An enlarged view showing the diffraction-limited performance of a collimated beam with a total divergence angle of less than 0.13 degrees. Figure 4E The spatial intensity distribution of the projected point at a distance of 100 mm from the projector is shown.

[0047] In another example ( Figures 5A to 5D In this context, planar optical devices (e.g., metasurfaces) contain superimposed phase profiles for beam collimation and / or projection (e.g., acting as wide FOV lenses) and beam separation, to generate a beam profile that is consistent with the beam collimation and / or projection (e.g., acting as wide FOV lenses) and beam separation. Figure 1D The pattern shown is similar to a dot array pattern. In this case, the deflection angle between each separate channel can be smaller than the FOV of a single channel. Furthermore, planar optics can be positioned in direct contact with the emitter array. Figure 5A A ray tracing simulation of an ultracompact pattern generation system design achieved with a reduced total track length is shown. The planar optical components collimate the light from the emitter and project it in different directions, and further separate each beam into multiple channels, thereby producing high-density, high-quality speckle projection. Figure 5B A ray tracing simulation of a single channel is shown. In this example, the projected beams from each emitter consist of 7×7 collimated beams, as indicated in the magnified image of the beam at the center. Figure 5C and Figure 5D Simulation results are shown to indicate the diffraction-limited beam quality of a collimated beam with a divergence angle of less than approximately 0.9 degrees. In this example, the system was designed with a wavelength of 940 nm, but other wavelengths can also be chosen.

[0048] This optical system can be configured to achieve various beam shaping functions, such as collimation, focusing, divergence, or other desired intensity and / or phase distributions. The projected optical pattern can be further engineered by controlling the position or arrangement of the emitter array and its optical characteristics (e.g., polarization, wavelength, angle of incidence, etc.). Additional optical elements (e.g., planar optics, refractive / reflective optics, microlens arrays, etc.) can be incorporated to further modify performance and / or functionality.

[0049] Figures 6A to 6E It shows the relationship with Figures 5A to 5D The depicted design exhibits point projection characteristics similar to those of other designs. (Targeting...) Figure 6A The exemplary light emitter array shown is (e.g., a VCSEL array). Figure 6BThe image shows the far-field angular distribution of a point array projected by a single-channel projector (without beam splitting). Each emitter is collimated and projected by planar optics of the projector and corresponds to a single point in the far field. The dFOV of the single-channel projector is approximately 120°. In the case of a beam-split phase profile with superimposed wave vectors, Figure 6C The far-field angular distribution of a multi-channel projector is shown, generating a projected array of five channels for each emitter. Each emitter corresponds to multiple projected points. In this case, the deflection angle between each separate channel can be smaller than the FOV of a single channel. Therefore, the dFOV of the multi-channel projector is similarly approximately 120°. Figure 6D It shows Figure 6C An enlarged view showing the diffraction-limited performance of a collimated beam with a total divergence angle of less than approximately 0.9 degrees. Figure 6E The spatial intensity distribution of the projected point at an exemplary projection distance of 100 mm is shown.

[0050] By altering the characteristics of the projected beam (e.g., divergence, size, intensity pattern, etc.), patterns with different characteristics (e.g., projection distance, spot size, intensity distribution) can be generated. By controlling the position, size, density, and / or phase gradient of the entire or sub-regions of the beam separation phase profile, the beam separation ratio between different channels, the beam size of each channel, the projection distance, and / or deflection angle can be changed. Planar optical devices may or may not be positioned in direct contact with the emitter array.

[0051] Figures 2A to 6E The pattern generation systems shown can achieve a one-to-one or one-to-many correspondence between the VCSEL aperture and the projected points. These pattern generation systems provide optimal beam quality (i.e., minimal aberrations), as well as customizable FOV, projection pattern, and channel density.

[0052] In another embodiment, the metasurface phase and / or amplitude profile can be designed by superimposing additional phase and / or amplitude modulation functions. For example, if one or more beam separation profiles are superimposed on the original beam shaping, projection, and / or phase separation profile, additional channels with more point arrays can be generated, thereby producing, for example, a result similar to... Figure 1E The pattern shown is similar to the pattern shown.

[0053] In other embodiments, the beam projection and / or splitting super-optical device can be used as an illuminator or diffuser when coupled with one or more emitters.

[0054] In another embodiment, the planar optics can be configured to provide a phase profile for beam collimation and projection (similar to the function of a microlens array), wherein different regions of the planar optics are designated for coupling different emitters, such as... Figure 7A As illustrated schematically, planar optical devices can further include beam-separating phase profiles superimposed on microlens phase profiles to produce multiple replicates of the projected pattern, thereby generating multiple point arrays, such as... Figure 7B As shown schematically.

[0055] Pattern projectors, illuminators, or diffusers can be paired with imagers formed by planar optics and image sensors to capture a scene illuminated by the projector. Figure 8 This schematically illustrates a structured light camera that combines a pattern projector and an imager, coupled together. The pattern projector includes an array of emitters 101 and planar optics 102, while the imager includes another planar optics 104 and a light receiver 105 (such as an image sensor). The imager can be designed to capture a portion or the entire scene, or only the area of ​​the scene illuminated by the pattern projector. This structured light camera architecture can be used for 3D sensing, structured light imaging, LiDAR, computing, etc. The projector and imager can be co-designed to achieve a correspondence between the emitter array and the image sensor array. The imager can be designed to capture only the area of ​​the scene illuminated by the pattern projector. The receiving metasurface 104 can also be designed to be sensitive to different characteristics of incident light (e.g., polarization, wavelength, angle of incidence, etc.), such that light with different characteristics will be directed to a designated detection channel or image sensor area of ​​the image sensor 105. The planar optics component 102 of the projector and the planar optics component 104 of the imager can be positioned on the same substrate 103 (see [reference]). Figure 8 The imager may be mounted on a substrate or a different substrate (not shown in the figures). Additional elements (a single element or an array of elements) may also be included and coupled to the imager, such as filters (e.g., spectral, polarization, spatial, and / or angular filters), refractive, diffractive, and / or reflective optical elements, light modulators, liquid crystal elements, etc. One example is a pixelated spectral filter array or a single filter coupled to an image sensor. Another example is a pixelated polarization filter array or a single filter coupled to an image sensor.

[0056] Figure 9A A multi-layer planar optics architecture (e.g., a two-metasurface structure) is schematically illustrated. This architecture can be used to provide a customized image height-to-AOI relationship (e.g., minimized distortion) while offering high imaging performance and a large FOV. Preferably, the two metasurfaces, spaced apart from each other in the vertical direction, have the same size and coincide in position when viewed vertically. First, a single-metasurface case can be designed using a model assuming no phase and / or refraction on the first metasurface layer. As an example, Figure 9B and Figure 9CTwo exemplary designs are shown, in which one of the two metasurfaces uses a quadratic phase profile, while the other has zero phase. In both cases, the position of the focal spot (or conversely, the emitter) increases linearly with sin(α), where α is the AOI (or conversely, the projection beam angle).

[0057] exist Figures 9A to 9C In the diagram, n1 and n2 represent the refractive indices of the two substrate material layers (between the two metasurfaces and between the image plane and the second metasurface, respectively); D and f represent the thicknesses of the two substrate layers, respectively; r1 and r2 represent the positions on the first and second metasurfaces, respectively; and s represents the position on the image plane. φ1 and φ2 are the phase profiles of the first and second metasurfaces, respectively.

[0058] The following text is for reference only. Figure 9D A specific example of lens phase profile design for quadratic phase is given. The phase gradient at radius r is:

[0059]

[0060] The ideal phase profile is:

[0061]

[0062] Consider the next VCSEL at position r+δr:

[0063] sin[α(r+δr)]·(s-δr)

[0064] Subtract equation (2) from equation (3), and use equation (1), assuming s is small:

[0065]

[0066] This gives the quadratic phase profile:

[0067]

[0068] A two-layer planar optical architecture can be used to customize the relationship between image height and AOI (e.g., minimal distortion) while providing high imaging quality. Figure 10A An exemplary design using two phase profiles is shown, which produces a linear relationship between image height and AOI (or conversely, the emitter position and beam projection angle), i.e., s = f·α / n. Figure 10BThe simulated far-field angular distribution of this projector design is shown, which assumes that the emitter array has equally spaced emitters, thereby producing a uniformly distributed, high-quality beam in the angular domain. In contrast, a single metasurface (e.g., using a quadratic phase profile) generates increasingly distorted patterns as the AOI increases, such as... Figure 10C As shown.

[0069] Furthermore, one or two of these phase profiles can be superimposed with one or more beam-separated phase profiles to provide combined light shaping, projection, and / or separation capabilities. Additional optics can be used to further improve performance and introduce new functionalities.

[0070] The multi-layer planar optical device design architecture described herein can simultaneously suppress aberrations and distortions, as well as provide additional beam manipulation capabilities.

[0071] In summary, the planar optics-based optical patterning architectures according to embodiments of the present invention employ hybrid super-optics, using one or more optical components to combine beam projection, splitting, deflection, and / or shaping to achieve optimal performance. These optical patterning architectures achieve: high beam quality, e.g., near diffraction limit; large field of view, e.g., up to 180°; customizable 2D or 3D projection patterns and / or channel densities; illumination patterns not limited to points; and high efficiency compared to DOE elements.

[0072] Those skilled in the art will appreciate that various modifications and alterations can be made to the optical pattern generation architecture and related methods based on planar optical devices of the present invention without departing from the spirit or scope of the invention. Therefore, it is contemplated that the present invention covers modifications and alterations falling within the scope of the appended claims and their equivalents.

Claims

1. An optical pattern projection device, comprising: One or more light emitters; as well as A first optical metasurface, coupled to the one or more emitters, is configured to project, reshape, and / or separate a light beam generated by the one or more emitters to generate a projected light pattern. The first metasurface layer contains at least two superimposed phase profiles that perform different functions on each other. Each of the at least two phase profiles is configured to modulate, collimate, focus, diverge, deflect, shape, separate, diffract, or diffuse a light beam from the one or more emitters.

2. The apparatus of claim 1, further comprising a second optical metasurface spaced apart from the first optical metasurface, the second optical metasurface containing an optical shaping and / or projection phase profile configured to modulate, collimate, focus, diverge, diffuse, and / or deflect a light beam from the one or more emitters, wherein, The first optical metasurface and the second optical metasurface cooperate with each other to establish a defined relationship between the position or optical properties of the emitter and the corresponding beam projection angle or optical properties.

3. The apparatus of claim 2, wherein, This constraint is a linear relationship between the position of the emitter and the beam projection angle.

4. The apparatus of claim 2, wherein, The first optical metasurface and the second optical metasurface have the same size.

5. The apparatus of claim 1, wherein, At least one of the at least two superimposed phase profiles is configured to separate or diffract the light so as to distribute the beams from each of the one or more emitters spatially or angularly into multiple channels.

6. The apparatus of claim 5, comprising a plurality of light emitters, wherein, The projected light pattern comprises multiple sub-patterns, each corresponding to one of these emitters.

7. The apparatus of claim 6, wherein, In the projected light pattern, the multiple sub-patterns are identical in shape and shifted relative to each other in position, and wherein the multiple sub-patterns overlap or do not overlap each other.

8. The apparatus of claim 1, wherein, The projected light pattern is a 2D or 3D pattern that includes one or more of the following: dot array, line, matrix, letter, graphic, hologram, random pattern, grayscale pattern, uniform pattern and diffuse pattern.

9. The apparatus of claim 1, wherein, The projected light pattern achieves a diagonal field of view of approximately 170°.

10. The apparatus of claim 1, further comprising a spacer positioned between the first optical metasurface and the one or more light emitters.

11. The apparatus of claim 1, wherein, The first optical metasurface is planar, curved, or conformally integrated with its substrate.

12. The apparatus of claim 1, wherein, The one or more emitters are one or more light sources, one or more optical channels, images, or light patterns.

13. The apparatus of claim 1, comprising a plurality of light emitters, wherein, The first optical metasurface is configured to provide different responses to different optical properties from the plurality of emitters, wherein these optical properties are the wavelength, polarization, incident angle, or intensity of the light beam.

14. The apparatus of claim 1, wherein, The one or more emitters are configured to emit light beams having the same or different optical properties, wherein these optical properties are wavelength, polarization, beam divergence, or order.

15. An optical pattern projection and detection apparatus, comprising the optical pattern projection apparatus as described in claim 1, wherein the optical pattern projection and detection apparatus further comprises an optical pattern detection apparatus, the optical pattern detection apparatus comprising: Another optical metasurface is configured to modulate, shape, collimate, focus, diverge, deflect, separate, diffract, or diffuse a light beam. as well as One or more light receivers are coupled to the other optical metasurface.

16. The apparatus of claim 15, wherein, The first optical metasurface and the other optical metasurface are formed on separate, partially overlapping, or fully overlapping portions of the same substrate.

17. The apparatus of claim 15, wherein, The optical receiver includes a photodetector or an optical channel.

18. An optical pattern projection device, comprising: An array of light emitters, comprising multiple light emitters; as well as One or more planar optical layers are configured to project and separate light beams generated by the plurality of emitters to generate a projected light pattern comprising a plurality of sub-patterns, each sub-pattern corresponding to one of the emitters, wherein the sub-patterns are identical in shape, displaced relative to each other in position, and overlap each other.

19. An optical pattern projection and detection apparatus, comprising the optical pattern projection apparatus as described in claim 18, wherein the optical pattern projection and detection apparatus further comprises an optical pattern detection apparatus, the optical pattern detection apparatus comprising: Another planar optical layer is configured to modulate, shape, collimate, focus, diverge, deflect, separate, diffract, or diffuse a beam. as well as A light receiver coupled to the other planar optical layer.

20. An optical pattern projection device, comprising: An array of light emitters, comprising multiple light emitters; as well as A planar optical element layer coupled to the emitter array is configured to project, reshape, and / or separate beams generated by the plurality of emitters to generate a projected light pattern comprising a plurality of sub-patterns, each sub-pattern corresponding to one of the emitters. The planar optical element layer includes superimposed phase profiles, including a phase profile for beam collimation and projection and a beam separation phase profile. In the phase profile for beam collimation and projection, different regions of the planar optical element are configured to couple beams from different emitters. The beam separation phase profile is configured to spatially distribute beams from each emitter into a plurality of channels.

21. An optical pattern projection and detection apparatus, comprising the optical pattern projection apparatus as described in claim 20, wherein the optical pattern projection and detection apparatus further comprises an optical pattern detection apparatus, the optical pattern detection apparatus comprising: Another planar optical layer is configured to modulate, shape, collimate, focus, diverge, deflect, separate, diffract, or diffuse a beam. as well as A light receiver coupled to the other planar optical layer.

22. An optical pattern projection device, comprising: One or more light emitters; as well as A single planar optical element layer, coupled to the emitter or emitter array, is configured to project, reshape, and / or separate a light beam generated by the one or more emitters to generate a projected light pattern.

23. The apparatus of claim 22, comprising a plurality of light emitters, wherein, The projected light pattern comprises multiple sub-patterns, each corresponding to one of these emitters.

24. The apparatus of claim 22, wherein, The single planar optical device layer is an optical metasurface containing superimposed phase profiles, including light-shaping and / or projection phase profiles and beam-separating phase profiles. The light-shaping and / or projection phase profiles are configured to collimate, focus, and / or deflect beams from the one or more emitters, and the beam-separating phase profiles are configured to spatially or angularly distribute beams from each emitter into multiple channels.

25. An optical pattern projection device, comprising: One or more light emitters; as well as Two planar optical layers, spaced apart from each other and having the same size, are configured to project, reshape, and / or separate a beam of light generated by the one or more emitters to generate a projected light pattern comprising multiple sub-patterns, each sub-pattern corresponding to one of the emitters.

26. The apparatus of claim 25, wherein, Each of the two planar optical layers is an optical metasurface containing light-shaping, projection, and / or phase-separation profiles configured to collimate, focus, deflect, and / or separate beams from the one or more emitters. The two planar optical layers cooperate with each other to establish a defined relationship between emitter position or optical characteristics and corresponding beam projection angles. At least one of the two planar optical layers further contains superimposed beam-separation phase profiles configured to spatially distribute beams from each emitter into multiple channels.

27. The apparatus of claim 26, wherein, This constraint is a linear relationship between the position of the emitter and the beam projection angle.

28. An optical pattern projection device, comprising: One or more light emitters; as well as Two optical metasurfaces, spaced apart from each other, are configured to project, reshape, and / or separate a light beam generated by the one or more emitters to generate a projected light pattern comprising multiple sub-patterns, each sub-pattern corresponding to one of the emitters. Each of the two optical metasurfaces contains a light-shaping, projection, and / or phase-separation profile configured to collimate, focus, and / or deflect a beam from the one or more emitters. The two optical metasurfaces cooperate with each other to establish a defined relationship between emitter position or optical characteristics and beam projection angle. At least one of the two optical metasurfaces further contains a superimposed beam-separation phase profile configured to spatially distribute the beam from each emitter into multiple channels.

29. The apparatus of claim 28, wherein, This constraint is a linear relationship between the position of the emitter and the beam projection angle.

30. The apparatus of any one of claims 18, 20, 22, 25, and 28, wherein, The projected light pattern is a 2D or 3D pattern that includes one or more of the following: dot array, line, matrix, letter, graphic, hologram, random pattern, grayscale pattern, uniform pattern and diffuse pattern.

31. The apparatus according to any one of claims 18, 20, 22, 25, and 28, wherein, The projected light pattern achieves a diagonal field of view of approximately 170°.

32. The apparatus of any one of claims 18, 20, 22, 25 and 28, further comprising a spacer positioned between the planar optical element layer and the one or more light emitters.

33. The apparatus of any one of claims 18, 20, 22, 25, and 28, wherein, The planar optical device layer is planar, curved, or conformally integrated with its substrate.

34. The apparatus of any one of claims 18, 20, 22, 25, and 28, wherein, The one or more emitters are one or more light sources, one or more optical channels, images, or light patterns.

35. The apparatus of any one of claims 18, 20, 22, 25, and 28, comprising a plurality of light emitters, wherein, The planar optical layer is configured to provide different responses to different optical characteristics from the plurality of emitters, wherein these optical characteristics are the wavelength, polarization, incident angle, or intensity of the light beam.

36. The apparatus of any one of claims 18, 20, 22, 25, and 28, wherein, The one or more emitters are configured to emit light beams having the same or different optical properties, wherein these optical properties are wavelength, polarization, beam divergence, or order.

37. An optical pattern projection and detection apparatus, comprising the optical pattern projection apparatus as claimed in any one of claims 22, 25, and 28, further comprising an optical pattern detection apparatus, the optical pattern detection apparatus comprising: Another planar optical layer is configured to modulate, shape, collimate, focus, diverge, deflect, separate, diffract, or diffuse a beam. as well as A light receiver coupled to the other planar optical layer.

38. The apparatus of claim 37, wherein, The planar optical device layer and the other planar optical device layer are formed on separate portions, partially overlapping portions, or completely overlapping portions of the same substrate.

39. The apparatus of claim 37, wherein, The optical receiver includes a photodetector or an optical channel.

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