Wide-angle metasurface optics, sensors, cameras and projectors

Abstract

A wide-angle sensor or projector includes a transparent substrate with one or more apertures on one side and one or more chip stacks bonded to the other side. Each chip stack includes a planar optical component layer (e.g., a metasurface), at least one spacer layer, an optional filter layer, and either an image sensor or a light source. In one example, two apertures and two corresponding chip stacks are provided, both of which include an image sensor but different metasurfaces and filters to capture different information from the scene. In an alternative embodiment, the two chip stacks include a light source and an image sensor to function as a light projector and a light receiver, respectively. In another example, two apertures and a single chip stack are provided, with the single chip stack including two metasurfaces and / or two filters corresponding to the two apertures.

Description

[Technical Field]

[0001] Background of the Invention The present invention relates to optical components and optical systems, in particular metasurfaces, metamaterials, imaging, sensing, projection, 3D sensors and depth sensing. [Background technology]

[0002] 3D depth sensing is a key technology for applications spanning biometrics, automotive detection, AR / VR, robotics, and industrial automation. Existing 3D optical sensors based on structured light, time-of-flight (TOF), or stereoscopic technologies are typically assembled from conventional bulk refractive optics and discrete components. Sensor optics involve multiple stacked lenses, which increase module thickness and assembly complexity. Furthermore, current 3D sensors are constrained by a narrow field of view (FOV, the angular range of a scene object that can be imaged by an optical system) typically less than 90° and lateral / spatial resolution that is usually limited to approximately 1,000 × 1,000 or less. When conventional optics are used, further performance improvement necessarily involves adding more elements. The trade-off between optical performance and thickness presents an increasing challenge not only for the realization of new architectures but also for the miniaturization of embedded sensors in mobile phones and other small electronic devices. Prevalent multi-element optical architectures thereby hinder further performance and cost scaling of 3D sensors. Summary of the Invention [Means for solving the problem]

[0003] Summary of the Invention Correspondingly, the present invention is directed to imaging, sensing and / or projection systems, such as 3D sensing systems, and related methods, that substantially eliminate one or more of the problems due to limitations and drawbacks of the related art.

[0004] Embodiments of the present invention provide novel imaging and sensing systems based on planar lens optics that feature superior optical performance, structural simplicity, and a compact footprint compared to their conventional counterparts based on bulk refractive optics.

[0005] The imager, sensor, or projector architecture, design, and modular configuration according to embodiments of the present invention leverage a novel optical metasurface architecture and packaging process to avoid complex multi-element assembly while enhancing optical performance compared to existing sensors. The imager, sensor, or projector design simultaneously seeks a large FOV (greater than 90°), high resolution, and a compact form factor. Furthermore, it features an architecturally simple configuration that is perfectly suited for wafer-scale assembly and packaging with a minimal number of elements, thereby offering significant advantages for scalable manufacturing and cost reduction.

[0006] Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof, as well as the appended drawings.

[0007] In order to achieve the above object, the present invention provides a sensor device comprising a transparent substrate, an opaque material layer over a first side of the substrate including at least one aperture, and a chip stack bonded to a second side of the substrate opposite the first side, the chip stack including a planar optical component layer, at least one spacer layer, and an image sensor located a predetermined distance from the planar optical component layer.

[0008] In another aspect, the present invention provides a projector device including a transparent substrate, a layer of opaque material over a first side of the substrate including at least one aperture, and a chip stack bonded to a second side of the substrate opposite the first side, the chip stack including a planar optics layer, at least one spacer layer, and a light source or light source array positioned a predetermined distance from the planar optics layer.

[0009] In some embodiments of the sensor or projector device, the planar optics layer comprises a metasurface, a diffractive optical element, a hologram, or a gradient index (GRIN) optical element. In some embodiments, the planar optics layer is formed with metasurface structures configured to control the optical phase, amplitude, polarization, and / or spectrum, angle- and / or polarization-dependent transmittance, reflection, and / or beam-shaping profile of incident light.

[0010] In some embodiments of the sensor or projector device, the chip stack further comprises a filter layer.

[0011] In some embodiments of the sensor or projector device, the device further comprises a printed circuit board, on which the image sensor or light source or light source array, as well as other associated electrical components, are mounted.

[0012] In some embodiments of the sensor device, the at least one aperture includes a first aperture and a second aperture, and the sensor further includes a second chip stack including a second planar optical component layer, at least one second spacer layer, and a second image sensor located a predetermined distance from the second planar optical component layer, wherein the chip stack and the second chip stack spatially correspond to the first and second apertures, respectively, and the planar optical component layer and the second planar optical component layer are configured to perform different functions depending on different properties of light.

[0013] In some embodiments of the sensor device, the at least one aperture includes a first aperture and a second aperture, and a single chip stack accommodates both apertures.

[0014] In another aspect, the invention provides a sensor device comprising a transparent substrate, a layer of opaque material over a first side of the substrate including at least one aperture, a first chip stack, and a second chip stack bonded to a second side of the substrate opposite the first side, the first chip stack comprising a first planar optical component layer, at least one first spacer layer, and an image sensor located a predetermined distance from the first planar optical component layer, and the second chip stack comprising a second planar optical component layer, at least one second spacer layer, and a light source or light source array located a predetermined distance from the second planar optical component layer. In some embodiments, the sensor device further comprises a printed circuit board, and the image sensor and the light source or light source array are mounted on the printed circuit board.

[0015] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. [Brief explanation of the drawings]

[0016] BRIEF DESCRIPTION OF THE DRAWINGS [Figure 1A] 1 illustrates schematically a sensor / imager useful for 3D sensors or other imaging, sensing, or projection applications according to an embodiment of the present invention, having multiple chip stacks corresponding to multiple apertures. [Figure 1B] 10A and 10B illustrate schematic diagrams of another sensor / imager useful for 3D sensors or other imaging, sensing, or projection applications according to another embodiment of the present invention, having multiple chip stacks corresponding to multiple apertures; [Figure 2A] 10A and 10B illustrate schematic diagrams of sensor / imagers useful for 3D sensors or other imaging, sensing, or projection applications according to additional embodiments of the present invention, having a single chip stack corresponding to multiple apertures; [Figure 2B] 10A and 10B illustrate schematic diagrams of sensor / imagers useful for 3D sensors or other imaging, sensing, or projection applications according to additional embodiments of the present invention, having a single chip stack corresponding to multiple apertures; [Figure 2C]10A and 10B illustrate schematic diagrams of sensor / imagers useful for 3D sensors or other imaging, sensing, or projection applications according to additional embodiments of the present invention, having a single chip stack corresponding to multiple apertures; [Figure 2D] 10A and 10B illustrate schematic diagrams of sensor / imagers useful for 3D sensors or other imaging, sensing, or projection applications according to additional embodiments of the present invention, having a single chip stack corresponding to multiple apertures; [Figure 3] 1 shows a schematic representation of a substrate with four apertures useful in some embodiments of the present invention. [Figure 4A] 1 illustrates an exemplary structure and simulated performance of a miniature Metasurface imaging device according to an embodiment of the present invention. [Figure 4B] 1 illustrates an exemplary structure and simulated performance of a miniature Metasurface imaging device according to an embodiment of the present invention. [Figure 5A] 1A-1C schematically illustrate a sensor device module incorporating a Metasurface planar optical component according to an embodiment of the present invention. [Figure 5B] 1A-1C schematically illustrate a sensor device module incorporating a Metasurface planar optical component according to an embodiment of the present invention. [Figure 5C] 1A-1C schematically illustrate a sensor device module incorporating a Metasurface planar optical component according to an embodiment of the present invention. [Figure 6] 5C illustrates, in perspective view, an exemplary sensor / imager module useful for 3D sensors or other imaging, sensing, or projection applications similar to that shown in FIG. 5B. [Figure 7] 1 illustrates another exemplary camera module according to an embodiment of the present invention. [Figure 8] 10A and 10B illustrate a manufacturing and assembly process for a sensor module according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] Detailed Description of the Invention Embodiments of the present invention may be used widely in imaging, sensing, and projection optical systems, as well as systems that combine such functionality.

[0018] 1A and 1B show schematic diagrams of two sensor / imagers (which may be used for 3D sensors or other imaging, sensing, or projection applications) according to two embodiments of the present invention. Each sensor includes a transparent substrate 11 that serves as a mechanical support for the other components. The substrate 11 may also function as a micro-optical bench, in which case its surface is patterned to form mechanical alignment features to aid in passive assembly of the components.

[0019] In the embodiment shown in FIG. 1A , the front side (object side) of substrate 11 is covered with an opaque material patterned to form one, two, or three or more apertures 12. This can be achieved, for example, by using lithography or printing methods to define the apertures in the opaque layer, e.g., metal or black ink, and by assembling a separate opaque layer, window, or light baffle containing the apertures to the substrate. On the back side, one, two, or three or more chip stacks 13 are assembled (e.g., glued) to substrate 11 and spatially correspond to apertures 12. Each stack 13 includes a planar optics layer 31, one or more spacers (which may be air gaps) 32 and 34 (two are shown in this example, but the second is optional), a filter 33, and an image sensor 35. Planar optics layer 31 may be a metasurface, a diffractive optical element, a hologram, a gradient index (GRIN) optical element, etc. The following description uses a metasurface as an example. A metasurface is defined herein as comprising subwavelength structures (i.e., meta-atoms) fabricated or assembled with a substrate to impart spatially varying optical phase delay and / or amplitude or polarization modulation to an incident wavefront. The meta-atoms and substrate can be made of the same or different optical materials. The meta-atoms are designed to alter the phase, amplitude, and / or polarization of incident light. The meta-atoms can have the same or different geometric shapes, dimensions, orientations, and / or pitches. Exemplary geometric shapes may include rectangular, cylindrical, freeform, or any other suitable shape or combination of different shapes. The pitch or lattice of meta-atoms can have any suitable shape and period (e.g., square, rectangular, or hexagonal). The lattice may also be aperiodic, where the distance between adjacent meta-atoms is varied or random. In some examples, the gap between adjacent meta-atoms can be designed to have a constant gap distance. One or both sides of the substrate may be flat or curved. Both the metasurface and the substrate may be rigid, flexible, or stretchable. The substrate may also include spacers.

[0020] The geometry, dimensions, and layout of the meta-atoms and substrates are designed to provide targeted optical functions. Metasurfaces can be designed to operate at a single wavelength, multiple wavelengths, or over a continuous spectral range. Metasurfaces can be designed to provide different functions depending on the properties of the incident light (e.g., polarization, wavelength, angle of incidence / emission, intensity, etc.).

[0021] Each metasurface 31 in combination with a corresponding aperture 12 forms a wide-angle FOV metalens capable of high-resolution imaging across an FOV of up to 180°. In its baseline configuration, light transmitted through aperture 12 is focused or redirected by metasurface 31 (with or without additional optical filters) across the wide-angle FOV to image sensor 35. Metasurface lenses (or metalenses) can be designed to operate at infrared wavelengths (e.g., 850 nm or 940 nm) and other wavelengths (e.g., in the visible spectrum) so as to be invisible to the human eye. They can also be designed for broadband operation.

[0022] Filter 33 may be a spectral, angular, and / or polarization filter. The filter may be in the form of a multilayer filter, a cavity structure, a diffractive optical element, a tilted grating, or a metasurface that performs the above filtering function. Angular filters (e.g., some cavity structures, diffractive optical elements, or metasurfaces that exhibit angular selectivity) may be used to block or reduce stray light or to form a self-limiting aperture depending on the incident or exit angle of the light. Polarization filters may also be useful when the metalens is designed to be polarization-sensitive. Metasurfaces may also be used as filters.

[0023] One feature of this embodiment is that it enables angle-selective filtering of background ambient light to increase signal-to-noise (SNR), which is not possible with conventional multilayer filters when applied to wide-field imaging. This is made possible by the (near-)telecentric configuration of the metalens, which means that light coming from different angles of incidence (AOIs) on the object side leaves the metalens only within its surface normal (or near-normal, e.g., within 20 degrees from the normal) exit cone. In other words, at any AOI, the chief ray of incident light leaves the metasurface in a direction perpendicular to the metasurface (or near-normal, e.g., within 20 degrees from the normal). Therefore, the tight distribution of light angles on the image side makes it possible to use a single bandpass filter to effectively reject ambient background light from all AOIs. Meanwhile, meta-atoms positioned at different locations on the metasurface can be designed differently (e.g., according to the AOI) to provide enhanced angle- or spatially-dependent responses.

[0024] The metasurface 31 and filter 33 may be further assembled (e.g., glued) to the image sensor 35 via an optical adhesive that also functions as a spacer to control the separation between the different components. The sensor is the outermost layer of the chip stack, and the spatial order of the metasurface 31, filter 33, and spacers or voids 32 and 34 can be changed from that shown in FIG. 1A, as long as the image sensor is located a predetermined distance from the metasurface. For example, the spacer or void 32 may be located between the filter layer 33 and the image sensor 35, or may not be between the metasurface and the image sensor.

[0025] The spacers or gaps 32 and 34, which serve to define the distances between the various layers, may be made of glass, plastic, etc., or a stack of materials, or gaps. For example, in wafer-level optics, the spacers may be layers of material of the required thickness with hollow cutouts in areas corresponding to the locations of the apertures to achieve the gaps. Alternatively, the entire layer may be air, and external mechanical structures may be used to hold other components and form the gaps. In this application, the term "spacer" includes gaps that may be formed by either of the above two structures or other suitable structures.

[0026] In an alternative embodiment, the two metasurfaces 31 corresponding to the two apertures 12 may perform different functions due to different properties of light (e.g., AOI, polarization, wavelength, etc.), and the two filters 33 may have correspondingly different optical filter properties. As a result, the different image sensors 35 may capture different information from the scene (e.g., different FOV, AOI, polarization, and / or spectral information, etc.) depending on the corresponding metasurface and filter structures.

[0027] In the embodiment shown in FIG. 1B , the two chip stacks 13-1 and 13-2 function as a light projector and a light receiver, respectively. In this case, the image sensor in the second stack 13-2 is replaced by a light source 36 (e.g., a light-emitting diode (LED) or a vertical-cavity surface-emitting laser (VCSEL), an LED / VCSEL array, or a display array). A filter 33 is optional in this stack. The second metasurface 31-2 in the second chip stack 13-2 is designed as a pattern projector or illuminator. The basic function of the second metasurface 31-2 is to convert the light emitted from the light source into a predetermined two-dimensional or three-dimensional optical intensity distribution (e.g., an array of discrete light rays that cluster in angular space, a structured pattern, etc.). The light rays exiting the second aperture 12-2 in front of the second metasurface 31-2 then form a convex dot pattern. In one example, the solid-immersion structure (i.e., no voids) of the second metasurface 31-2 allows the output light rays to cover the entire hemisphere upon refraction at the top surface of the substrate 11. In addition to dot arrays, the second metasurface 31-2 can also be easily designed to output other structured or diffuse light patterns with a required intensity distribution (e.g., an image, dots, lines, a random pattern, or any other light intensity distribution pattern). In an imager module, the first metasurface 31-1 in the first chip stack 13-1, in addition to the integrated sensor 35, then forms a light receiver for capturing a scene illuminated by a light source or ambient light. In a 3D sensor module, the first metasurface 31-1 in the first chip stack 13-1, in addition to the integrated image sensor 35, then forms a light receiver for capturing the reflection of the dot pattern, from which depth information can be inferred using structured light or TOF techniques.

[0028] In other embodiments (e.g., Figures 2A-2D), multiple apertures can be integrated with a single chip stack and / or a single image sensor to achieve stereoscopic imaging. A single planar (flat) optical component layer can carry one or more metasurfaces designed to modulate the properties (phase, amplitude, and / or polarization) of light from multiple corresponding apertures. For example, different regions of the metasurface can be designed for different apertures. In another example, a metasurface can be designed to have multiplexed functions such that light incident from different apertures is modulated differently.

[0029] An example is shown schematically in FIG. 2A , in which two metasurfaces 41-1 and 41-2 in a single chip stack 14, corresponding to two apertures 12-1 and 12-2, couple light to two different regions of a single image sensor 45. The image sensor 45 is integrated with a filter 43, both of which are large enough to spatially overlap the regions of the two metasurfaces. The captured images can then be used to generate a 3D image. One or two spacers 42 and 44 may also be provided in the chip stack 14. Unlike existing 3D sensing technologies that require multiple individually assembled optical modules, the highly integrated, all-planar architecture in this embodiment allows for a significantly simplified assembly process, improved performance with minimal misalignment, ultra-compact module configuration, and reduced cost.

[0030] Another example is shown schematically in FIG. 2B. In this embodiment, instead of a single filter, a single chip stack 15 includes multiple filters / filter zones 53-1 and 53-2, referred to as pixelated filter arrays, coupled with corresponding metasurfaces 51-1 and 51-2 or image sensor 55. In some examples, the metasurfaces 51-1 and 51-2 can be configured with filter characteristics to enable different regions or pixels of the image sensor 55 to capture different information of the scene (e.g., different AOIs, polarization, and / or spectral information). The pixelated filter arrays 53-1 and 53-2 can be integrated directly into the image sensor and aligned to the pixels. One or two spacers 52 and 54 can also be provided in the chip stack 15.

[0031] 2C , in a single chip stack 16, a single metasurface 61 can be designed to provide multiplexing functionality, such that it performs different optical modulation depending on the light properties (polarization, wavelength, AOI, etc.). Two or more filters or pixelated filter arrays 63-1 and 63-2 with different optical filter properties due to the metasurface functionality can be coupled to an image sensor 65. As a result, different regions or pixels of the image sensor 65 can capture different information of the scene (e.g., different AOI, polarization, and / or spectral information, etc.) depending on the corresponding metasurface and filter structures. Again, one or two spacers 62 and 64 can be provided in the chip stack 16.

[0032] 2D, filters 73-1 and 73-2 can be integrated on the front side of substrate 11 or near and covering apertures 12-1 and 12-2, respectively. Metasurfaces may be used as each of the filters. A single chip stack 17 on the back side of substrate 11 includes metasurface 71, spacer 72, and image sensor 75.

[0033] In further embodiments, while using a single flat optical layer and a single image sensor according to the embodiments of Figures 2A, 2B, 2C or 2D, three or more apertures may be used to provide full range stereoscopic sensing in both the horizontal and vertical directions, as shown in the top view at the bottom of Figure 3 (four apertures shown).

[0034] 4A and 4B show an example structure and simulated performance (camera) of a miniature metasurface imaging device according to the embodiment of FIG. 1A (not all layers of the chip stack are shown in FIG. 4A). The camera structure houses an ultra-small, commercially available CMOS image sensor 35. The metasurface 31 comprises an amorphous Si nanopillar array on a glass substrate. This type of metasurface structure has been previously described. In the example of FIG. 4, meta-atoms positioned at different locations on the metasurface (with different AOIs) are designed differently to provide enhanced angle- or spatial-dependent response. The metasurface substrate is assembled (e.g., glued) to the image sensor and attached to a custom miniature printed circuit board for image output. In this particular example, the input aperture is 0.18 mm in diameter, the metasurface is 0.5 mm in diameter, and the image sensor area is 0.36 mm. 2 The distance between the aperture and the metasurface is 0.21 mm, and the distance between the metasurface and the sensor surface is 0.16 mm. The metalens and sensor module achieves a FOV of up to 180 degrees, combined with a diameter as small as 0.5 mm, a total thickness of less than 0.4 mm, and a resolution better than 100 cycles / mm.

[0035] FIG. 4A shows a ray trace simulation of the imaging device. FIG. 4B is a plot of the simulated modulation transfer function (MTF) of the camera, demonstrating excellent resolution across the entire nearly 180-degree FOV. As shown in FIG. 4A, the metalens has a telecentric configuration, where the chief ray of incident light leaves the metasurface in a direction perpendicular to the metasurface for all angles of incidence within the FOV. As previously mentioned, a telecentric or near-telecentric configuration of a metalens achieves a 180-degree FOV with good image quality, even at large angles. In this disclosure, near-telecentric refers to a configuration in which the chief ray angle (i.e., the angle at which the chief ray of incident light leaves the metasurface) is less than 20 degrees for all angles of incidence. A near-telecentric (including telecentric) configuration is achieved through the selection of the aperture size (i.e., f-number) relative to the metasurface design and substrate thickness. Numerical optimization techniques may be used to achieve such a configuration. In various specific examples of sensors having the general structure shown in FIG. 4A, the f-number of the metalens ranges from 0.8 to 8.0.

[0036] An important advantage of the above-described 3D sensor according to various embodiments of the present invention is that a single-block chip stack structure can be fabricated using wafer-level processes to achieve excellent alignment accuracy, high manufacturing throughput, and low manufacturing costs. Using an image sensor stack as an example, the process begins with a complementary metal-oxide-semiconductor (CMOS) image sensor wafer, followed by sequential bonding of the filter and metasurface. The filter and metasurface are fabricated on or assembled with separate substrates (e.g., glass or semiconductor wafers or polymer substrates) preferably sized to match the size of the CMOS sensor wafer. The filter can be fabricated from a multilayer thin film that functions as an interference coating or a patterned metasurface layer with tailored spectral, angular, and / or polarization-dependent transmittance properties. In another embodiment, the metasurface and filter can be combined onto a single substrate. For example, the metasurface itself can also perform a filter function by engineering the metasurface structure to control the optical phase and / or spectral, angular, and / or polarization-dependent transmittance profile. Alternatively, the metasurface can also be patterned on top of a multilayer interference-coated filter. The metasurface can also be sandwiched between two multilayer interference coating filters. In yet another embodiment, a multilayer stacked metasurface structure can be employed to impart optical phase delay, amplitude modulation, polarization sensitivity, and / or spectral and / or angular filtering to incident light. Optical adhesive or transparent epoxy can be used as an adhesive while simultaneously functioning as a spacer layer with controllable thickness.

[0037] Another alternative fabrication and assembly process is shown in FIG. 8. In this process, the metasurface is fabricated as one piece with encapsulation (e.g., using epoxy or insulator) (step S81), the aperture is fabricated as one piece in the substrate (step S82), and the spacer and filter are fabricated as one piece (step S83). Each of these pieces includes multiple units of related structure. The metasurface piece is assembled (e.g., glued) to the aperture and substrate piece (step S84), and the spacer and filter piece is then assembled (e.g., glued) to the metasurface piece (step S85). The assembled structure is then diced into individual units (step S86), each including one (or two) sets of aperture, metasurface, and filters that form a metalens (or other meta-optical component). The metalens is then assembled (e.g., glued) to the image sensor (step S87). The various bonding steps may use optical adhesives, which themselves may function as additional spacers. The edges of the metalens and spacers may be blackened or roughened. In an alternative method, the apertures and metasurfaces may be combined on one substrate, i.e., the apertures and metasurfaces are patterned on opposite sides of a single substrate. The apertures may be optical apertures or mechanical apertures (e.g., frames for packaging, support, etc.).

[0038] A metasurface, or a portion of a metasurface, can be designed to be sensitive to the incident / exit angle or position of light. For example, different regions of a metalens can be configured to have different modulation behaviors (e.g., transmittance, phase retardation, polarization modulation, spectral response, etc.) depending on the light incident or exit angle or position on the metasurface. In one example, a metasurface, one or more regions of a metasurface, or a surrounding region of a metalens can be designed to deflect, reflect, absorb, diffract, or block light, thereby functioning as an aperture or light baffle element that can be useful for limiting light propagation or reducing / blocking stray light. For example, a metasurface grating or other meta-optic structure / component can be designed to deflect light to improve the optical efficiency of the metasurface for light within or outside a particular incident / exit angle range or diffraction order. Such metasurface optical components can be optimized for different incident / exit angles or diffraction orders. The dimensions, geometry, and / or pitch of the meta-atoms are optimized to improve the diffraction efficiency for a targeted diffraction angle θ under a specific entrance / exit angle α (or range of angles). The design begins with a unit cell full-wave simulation of meta-atoms with a period and entrance angle determined by the requirements. In one example, an 8-meta-atom library is generated with phase delays spanning the 0-2π range. Meta-optic components are then constructed from the library, and full-wave simulations (e.g., RCWA, FDTD, FEM, etc.) are used to simulate the diffraction efficiency of the meta-optic component (e.g., in the form of a metalattice). In one example, the AOI-dependent design exhibits three times the diffraction efficiency compared to meta-atoms designed for normal incidence, which can be used for metasurface regions with off-axis incident light or to effectively deflect stray light. Such design methods can be used not only for grating structures but also for other metasurfaces in general (e.g., metalenses).

[0039] 5A-5C schematically illustrate a sensor device module integrated metasurface planar optical component according to an embodiment of the present invention.

[0040] As shown schematically in FIG. 5A , the exemplary stereoscopic 3D sensor module includes two sub-modules: a first camera 100-1 and a second camera 100-2, each including a wide-angle FOV metalens (metasurfaces 103-1 and 103-2, respectively, with corresponding apertures 102-1 and 102-2 formed in a substrate 101) and an imager sensor 106. The image sensors 106 are further integrated with respective optical filters 105. In some embodiments, a spacer 104 may be included between the filters 105 and the metasurfaces 103-1 and 103-2. In the illustrated embodiment, the two metasurfaces 103-1 and 103-2 are integrated as one piece, while the two image sensors (with corresponding filters and optional spacers) are separate pieces. The image sensor 106, as well as an image processor 109 and other electronic components, are mounted on a printed circuit board (PCB) 108. In the illustrated embodiment, a windshield 107 is also provided to cover the front side of the plate.

[0041] 5B shows an exemplary imager / sensor with active illumination (e.g., a structured light or TOF 3D sensor module or other imager / sensor coupled with an illumination source). The module includes two sub-modules: projector 200-1, which includes light source 211 (e.g., a VCSEL or LED, or light array), driver chip 210 for the light source, and metaprojector optics (a first metasurface 203-1 formed in substrate 201 with corresponding apertures 202-1 to generate a high-resolution illumination pattern (e.g., a dot array)); and imager (camera) 200-2, which includes a wide-angle FOV metalens (a second metasurface 203-2 formed in substrate 201 with corresponding apertures 202-2) that captures an image of the pattern and maps it onto imager sensor 206. Filter 205 is integrated with image sensor 206. Optional spacers 204 may be provided in protector 200-1 and camera 200-2. The projector meta-optics may be inversely designed and co-optimized with the imager meta-optics to provide a large FOV of up to 180 degrees and high-resolution illumination and detection. The image sensor 206, its associated image processor 209, light source 211 and its driver 210, and other suitable electronic components are mounted on a printed circuit board (PCB) 208. In the illustrated embodiment, an optional windscreen 207 is also provided to cover the front side of the board.

[0042] 5C shows an imager / sensor module similar to that shown in FIG. 5B, but omitting spacer 204 and with filter 205 formed on second metasurface 203-2 rather than on image sensor 206. As a result, air gaps exist between light source (VCSEL) 211 and first metasurface 203-1, and between image sensor 206 and filter 205. The air gaps are maintained by mechanical fixtures and / or spacer structures (not shown in FIG. 5C) that attach substrate 201 (with metasurface) to PCB 208. Additionally, an optional backsheet 212 is provided below PDB 208.

[0043] In the examples of Figures 5A-5C, the front aperture can be further integrated with another optical component (e.g., a planar optic or a filter) to provide additional modulation of the incident light. Refractive or reflective optical components (e.g., lenses or mirrors) can also be used to form a hybrid optical system. Unlike existing imagers / sensors (e.g., 3D sensors) that involve separately packaged optical and opto-mechanical modules, the meta-optical components (metalens and metaprojector optics) in the embodiments of Figures 5A and 5B are coplanarly integrated on a single common substrate, which facilitates assembly and enables further functional scaling.

[0044] Figure 6 shows a perspective view of an exemplary imager / sensor module (e.g., a 3D sensor module) similar to that shown in Figure 5B. Panel (a) is an exploded view of the sensor module, panel (b) is a perspective view, and panel (c) is a top view of the PCB.

[0045] FIG. 7 shows another exemplary camera module. A metalens fixture and spacer structure 213 is shown positioned between the substrate and the filter around the area of ​​the metasurface and filter. The metalens fixture and spacer structure 213 and the substrate are surrounded by sidewalls 214. The various dimensions shown in FIG. 7 are exemplary and not limiting.

[0046] The 3D sensor module shown in Figures 5A, 5B, and 6 overcomes the traditional trade-off between performance, complexity, and size, uniquely combining high resolution, panoramic FOV, enhanced SNR, and a thin and lightweight device structure.

[0047] The sensor device module structure shown in Figures 5A and 5B can be used to implement other devices, such as near-IR or short-wave IR cameras similar to cameras 100-1, 100-2, or 200-2 but possibly without a processor, or illuminators similar to projector 200-1 but without a driver.

[0048] In the above-described embodiments, the metasurface may more generally be a planar optical layer, which may be, in addition to a metasurface, a diffractive optical element, a hologram, a gradient index (GRIN) optical element, etc. The front aperture may be further integrated with another optical component (e.g., a planar optical element or a filter) to provide additional modulation of the light. Refractive or reflective optical elements (e.g., lenses or mirrors) may also be used to form a hybrid optical system.

[0049] Various other alternative embodiments are possible. For example, apertures or light baffles can be patterned, integrated, or fabricated in one or more optical component layers of the various embodiments described above, which function to restrict light propagation or reduce or block stray light. The light baffles can be, for example, absorptive and / or reflective coatings, such as black or metallic coatings, or polarizing optical structures.

[0050] In another alternative embodiment, the space between the front aperture 12 and the Metasurface 31 may be an air gap.

[0051] The wide-angle FOV sensor structure described above can be designed and optimized for different types of applications, such as driver monitoring systems (DMS), eye trackers, and AR / VR (augmented reality / virtual reality) devices.

[0052] It will be apparent to those skilled in the art that various modifications and variations can be made in the Metasurface 3D sensor and camera and related methods of the present invention without departing from the spirit or scope of the invention. Accordingly, it is intended that the present invention cover modifications and variations that come within the scope of the appended claims and their equivalents.

Claims

1. A sensor device, A transparent substrate; a layer of opaque material over a first side of the substrate including at least one aperture; a chip stack adhered to a second side of the substrate opposite the first side, the chip stack comprising: a planar optical component layer; at least one spacer layer; an image sensor positioned a predetermined distance from the planar optics layer; a chip stack including a sensor device comprising:

2. 10. The sensor device of claim 1, wherein the planar optics layer comprises a metasurface, a diffractive optical element, a hologram, or a gradient refractive index (GRIN) optical element.

3. 10. The sensor device of claim 1 , wherein the planar optics layer comprises a metasurface, the metasurface spatially corresponding to one of the at least one aperture to form a near-telecentric metalens.

4. 10. The sensor device of claim 1, wherein the planar optical component layer is formed with a metasurface structure configured to control the optical phase, amplitude, polarization and / or spectrum, angle and / or polarization dependent transmittance, reflection and / or beam shaping profile of incident light.

5. the at least one aperture includes a first aperture and a second aperture; the sensor is a second chip stack, a second planar optical component layer; and at least one second spacer layer; a second image sensor positioned a predetermined distance from the second planar optical component layer; and a second chip stack including:

2. The sensor device of claim 1, wherein the chip stack and the second chip stack spatially correspond to the first and second apertures, respectively, and the planar optical component layer and the second planar optical component layer are configured to perform different functions depending on different properties of light.

6. 6. The sensor device of claim 5, wherein the chip stack further includes a first filter layer and the second chip stack further includes a second filter layer, the first filter layer and the second filter layer being configured to have different optical filter characteristics due to the different functions of the planar optical component layer and the second planar optical component layer, respectively.

7. a printed circuit board, the image sensor of the chip stack and the second image sensor of the second chip stack being attached to the printed circuit board; an image processor mounted on the printed circuit board; The sensor device of claim 5 further comprising:

8. the at least one aperture includes a first aperture and a second aperture; the sensor is a second chip stack, a second planar optical component layer; and at least one second spacer layer; a light source positioned a predetermined distance from the second planar optical component layer; a second chip stack including: the chip stack and the second chip stack spatially correspond to the first and second apertures, respectively; The sensor device of claim 1 , wherein the second planar optics layer is configured to convert light emitted by the light source into a predetermined two-dimensional or three-dimensional optical intensity distribution.

9. The sensor device of claim 8 , wherein the second chip stack further comprises a second filter layer.

10. a printed circuit board, on which the image sensor of the first chip stack and the light source of the second chip stack are mounted; a light source driver chip mounted on the printed circuit board; an image processor mounted on the printed circuit board; The sensor device of claim 8 further comprising:

11. The sensor device of claim 1 , wherein the chip stack further comprises a filter layer.

12. the at least one aperture includes a first aperture and a second aperture; the planar optics layer includes a first metasurface and a second metasurface that spatially correspond to the first and second apertures, respectively; The sensor device of claim 11 , wherein both the filter layer and the image sensor spatially overlap areas of the first and second metasurfaces.

13. the at least one aperture includes a first aperture and a second aperture; the planar optics layer includes a first metasurface and a second metasurface that spatially correspond to the first and second apertures, respectively; the filter layer includes first and second filters spatially corresponding to the first and second apertures, respectively; The sensor device of claim 11 , wherein the image sensor spatially overlaps areas of the first and second metasurfaces and the first and second filters.

14. the at least one aperture includes a first aperture and a second aperture; the filter layer includes first and second filters spatially corresponding to the first and second apertures, respectively; The sensor device of claim 11 , wherein both the planar optics layer and the image sensor spatially overlap areas of the first and second filters.

15. 12. The sensor device of claim 11, wherein the planar optical component layer is located between the image sensor and the substrate, the at least one spacer layer includes a first spacer layer located between the planar optical component layer and the image sensor, and the filter layer is located between the first spacer layer and the image sensor.

16. The sensor device of claim 15 , wherein the at least one spacer layer further comprises a second spacer layer positioned between the filter layer and the image sensor.

17. 12. The sensor device of claim 11 , wherein the planar optical component layer is located between the image sensor and the substrate, the filter layer is located between the planar optical component layer and the image sensor, and the at least one spacer layer includes a first spacer layer located between the filter layer and the image sensor.

18. 12. The sensor device of claim 11 , wherein the image sensor is a complementary metal-oxide semiconductor (CMOS) image sensor wafer, the filter layer is a multilayer thin film or patterned metasurface layer formed on a substrate and assembled to the image sensor wafer, and the planar optics layer is a metasurface formed on a substrate and assembled to the filter layer.

19. 12. The sensor device of claim 11, wherein the planar optics layer and the filter layer are formed with metasurface structures configured to control the optical phase, amplitude, polarization and / or spectrum, angle and / or polarization dependent transmittance, reflection and / or beam shaping profile of incident light.

20. 12. The sensor device of claim 11 , wherein the filter layer comprises one or more multi-layer interference coating filters and the planar optical metasurface layer is a metasurface patterned on top of the one or more multi-layer interference coating filters or sandwiched between two of the one or more multi-layer interference coating filters.

21. 12. The sensor device of claim 11 , wherein the planar optics layer and the filter layer are formed of multi-layer stacked metasurfaces or optical structures configured to impart optical phase, amplitude modulation, polarization sensitivity, and / or spectral and / or angular dependent filtering and / or beam shaping to incident light.

22. The sensor device of claim 1 , further comprising a filter covering each of the at least one aperture.

23. The sensor device of claim 1 , wherein the at least one spacer layer includes a first spacer layer that is an air gap.

24. 1. A projector device, comprising: A transparent substrate; a layer of opaque material over a first side of the substrate including at least one aperture; a chip stack adhered to a second side of the substrate opposite the first side, the chip stack comprising: a planar optical component layer; at least one spacer layer; a light source or light source array located at a predetermined distance from the planar optical component layer; a chip stack including a projector device.

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