Hybrid refractive and META-optical lens camera module

Abstract

A hybrid lens optical imaging system is provided herein. The hybrid lens optical imaging system includes a refractive lens having a curved front surface and a planar rear surface, a meta-optical element stack having at least one meta-optical element structure disposed on a substrate, and an image sensor having a maximum image circle diameter. The planar rear surface of the refractive lens is bonded to a front side of the meta-optical element stack, and a rear side of the meta-optical element stack is bonded to the image sensor. Additionally, a ratio of a total track length of the hybrid lens optical imaging system to the maximum image circle diameter of the image sensor is less than 1.3.

Description

NIL Technology ApSF&R Ref.: 47717-0073WO1 PCT ApplicationHYBRID REFRACTIVE AND META-OPTICAL LENS CAMERA MODULEFIELD OF INVENTION

[0001] The present disclosure relates to optical imaging systems, and more particularly to a hybrid lens camera module.BACKGROUND

[0002] Optical imaging systems have evolved to meet increasing demands for compact, high-performance camera modules across various applications including smartphones, automotive systems, and specialized imaging devices. Traditional refractive lens systems typically require multiple lens elements to achieve acceptable optical performance, resulting in increased size, weight, and manufacturing complexity. Meta-optical elements, which utilize subwavelength structures to manipulate light, have emerged as a promising technology for creating ultra-thin optical components. However, meta-optical elements alone often face limitations in achieving broadband performance and correcting various optical aberrations across wide fields of view.SUMMARY

[0003] The present disclosure provides a hybrid lens optical imaging system that combines a refractive lens with a meta-optical element stack to achieve compact, high- performance imaging. The system comprises a refractive lens having a curved front surface and a planar rear surface that is bonded to a meta-optical element stack containing at least one meta-optical element structure on a substrate, with the meta-optical element stack bonded to an image sensor. The hybrid design achieves a total track length to maximum image circle diameter ratio of less than 1.3, enabling ultra-compact camera modules while maintaining optical performance comparable to conventional multi-element lens systems through the strategic integration of refractive and meta-optical components.

[0004] In general, in some aspects, the subject matter of the present disclosure is directed to a hybrid lens optical imaging system, including: a refractive lens comprising a curved front surface and a planar rear surface; a meta-optical element stack comprising at least one meta- optical element structure disposed on a substrate, in which the planar rear surface of the refractive lens is bonded to a front side of the meta-optical element stack; and an imagesensor, in which the refractive lens and the meta-optical element stack together provide a maximum image circle diameter that is greater than a maximum dimension of an image sensing area of the image sensor, in which a rear side of the meta-optical element stack is bonded to the image sensor, and in which a ratio of a total track length of the hybrid lens optical imaging system to the maximum image circle diameter of the image sensor is less than 1.3.

[0005] Implementations of the hybrid lens optical imaging system can include one or more of the following features. For example, in some implementations, the meta-optical element stack includes at least two meta-optical element structures.

[0006] In some implementations, the at least two meta-optical element structures are disposed on separate substrates that are directly bonded together without an air gap.

[0007] In some implementations, the refractive lens includes a meniscus-shaped lens, in which the curved front surface is convex, and in which a portion of the planar rear surface surrounds a concave rear surface of the refractive lens.

[0008] In some implementations, the system includes an adhesive layer, in which the planar rear surface of the refractive lens is bonded directly to the meta-optical element stack through the adhesive layer.

[0009] In some implementations, the refractive lens includes a planoconvex-shaped lens, in which the curved front surface is a convex surface.

[0010] In some implementations, the system includes an adhesive layer, in which the planar rear surface of the planoconvex-shaped lens is directly bonded to the meta-optical element stack through the adhesive layer.

[0011] In some implementations, the system further includes an aperture stop between the refractive lens and the meta-optical element stack.

[0012] In some implementations, a first meta-optical element structure is inside the aperture stop.

[0013] In some implementations, the meta-optical stack includes an aperture stop, in which the planar rear surface of the refractive lens is bonded directly to a first surface of the meta-optical stack, and in which the aperture stop is located at a position that is different from the first surface of the meta-optical stack.

[0014] In some implementations, the meta-optical stack includes a first substrate, in which the planar rear surface of the refractive lens is bonded directly to a first surface of the first substrate, and in which the aperture stop is located at a second surface of the first substrate, the second surface being on an opposite side of the first substrate from the first surface of the first substrate.

[0015] In some implementations, the meta-optical stack includes a first substrate, a second substrate, in which the first substrate is bonded to the second substrate, a first meta- optical element structure on the first substrate, and a second meta-optical element structure on the second substrate.

[0016] In some implementations, the first meta-optical element structure is on a first surface of the first substrate that faces away from the refractive lens, and the second meta- optical element structure is on a first surface of the second substrate that faces away from the refractive lens.

[0017] In some implementations, the first meta-optical element structure is on a first surface of the first substrate that faces the refractive lens, and the second meta-optical element structure is on a first surface of the second substrate that faces away from the refractive lens.

[0018] In some implementations, the first meta-optical element structure is on a first surface of the first substrate that faces the refractive lens, and the second meta-optical element structure is on a first surface of the second substrate that faces the refractive lens.

[0019] In some implementations, the first meta-optical element structure is on a first surface of the first substrate that faces away from the refractive lens, and the second meta- optical element structure is on a first surface of the second substrate that faces the refractive lens.

[0020] In some implementations, the first substrate is separated from the second substrate by a spacer structure.

[0021] In some implementations, the meta-optical stack includes a first substrate, a first meta-optical element structure on a first side of the first substrate, and a second meta-optical element structure on a second opposite side of the first substrate.

[0022] In some implementations, the system includes an outer light absorbing layer, in which image sensor is configured to sense light having one or more wavelengths, and inwhich the outer light absorbing layer is configured to absorb light having the one or more wavelengths.

[0023] In some implementations, the light absorbing layer extends from the imaging sensor, along sides of the meta-optical element stack to the refractive lens.

[0024] In some implementations, the rear side of the meta-optical element stack is directly bonded to the image sensor without an air gap.

[0025] In some implementations, the system includes a die attach adhesive on the image sensor, in which the rear side of the meta-optical element stack is bonded to the image sensor via the die attach adhesive.

[0026] In some implementations, the system includes: a cover glass on the image sensor; and a die attach adhesive that bonds the cover glass to the image sensor; and an adhesive layer, in which the rear side of the meta-optical element stack is bonded to the cover glass via the adhesive layer.

[0027] In some implementations, the system includes a light filter layer between the meta-optical element stack and the image sensor.

[0028] In general, in some other aspects, the presently disclosed subject matter is directed to a method of manufacturing a hybrid lens optical imaging system. Particularly, the method includes: providing a refractive lens having a curved front surface and a planar rear surface: providing a meta-optical element stack comprising a substrate and at least one meta- optical element structure on the substrate: providing an image sensor; directly bonding the planar rear surface of the refractive lens to a front side the meta-optical element stack using an adhesive layer; and bonding a rear side of the meta-optical element stack to the image sensor, in which the refractive lens and the meta-optical element stack, when bonded to the image sensor, provide a maximum image circle diameter that is greater than a maximum dimension of an image sensing area of the image sensor, and in which a ratio of a total track length of the hybrid lens optical imaging system to the maximum image circle diameter of the image sensor is less than 1.3.

[0029] The methods may include one or more of the following features. For example, in some implementations, the meta-optical element stack includes at least two meta-optical element structures disposed on separate substrates.

[0030] In some implementations, the method further includes a step of directly bonding the separate substrates together without an air gap between them.

[0031] In some implementations, the refractive lens includes a planoconvex-shaped lens wherein the curved front surface is a convex surface.

[0032] In some implementations, the refractive lens includes a meniscus-shaped lens, in which the curved front surface is convex, and in which the planar rear surface surrounds a concave rear surface of the refractive lens.

[0033] In some implementations, the method further includes a step of providing an aperture stop between the refractive lens and the meta-optical element stack.

[0034] In some implementations, the method includes providing an outer light absorbing layer on outer sides of the meta-optical element stack, in which image sensor is configured to sense light having one or more wavelengths, and in which the outer light absorbing layer is configured to absorb light having the one or more wavelengths.

[0035] The foregoing general description of the illustrative embodiments and the following detailed description thereof are merely exemplary aspects of the teachings of this disclosure and are not restrictive.BRIEF DESCRIPTION OF FIGURES

[0036] Non-limiting and non-exhaustive examples are described with reference to the following figures.

[0037] FIG. 1 illustrates a cross-sectional view of an example hybrid lens optical imaging system according to aspects of the present disclosure.

[0038] FIG. 2A depicts an example hybrid lens optical imaging system according to aspects of the present disclosure.

[0039] FIG. 2B depicts an example hybrid lens optical imaging system according to aspects of the present disclosure.

[0040] FIG. 3 depicts a cross-sectional view of an example hybrid lens optical imaging system according to aspects of the present disclosure.

[0041] FIG. 4A illustrates a cross-sectional view of an example hybrid lens optical imaging system.

[0042] FIG. 4B shows a cross-sectional view of an example hybrid lens optical imaging system.

[0043] FIG. 5A depicts a cross-sectional view of an example hybrid lens optical imaging system.

[0044] FIG. 5B illustrates a cross-sectional view of an example hybrid lens optical imaging system according to aspects of the present disclosure.

[0045] FIG. 6 presents a table showing example optical specifications for hybrid lens optical imaging system designs according to aspects of the present disclosure.

[0046] FIG. 7A is a plot of example modulation transfer functions versus spatial frequency for a first example hybrid lens optical imaging system design.

[0047] FIG. 7B is a plot of example modulation transfer function versus focus shift for the first example hybrid lens optical imaging system design.

[0048] FIG. 8A is a plot of example modulation transfer functions versus spatial frequency for a second example hybrid lens optical imaging system design.

[0049] FIG. 8B is a plot of example modulation transfer function versus focus shift for the second example hybrid lens optical imaging system design.

[0050] FIG. 9A is a plot of example modulation transfer functions versus spatial frequency for a third example hybrid lens optical imaging system design.

[0051] FIG. 9B is a plot of example modulation transfer function versus focus shift for the third example hybrid lens optical imaging system design.

[0052] FIG. 10 is a schematic that illustrates an example method of fabricating a hybrid lens imaging system according to the present disclosure.DETAILED DESCRIPTION

[0053] The following description sets forth exemplary aspects of the present disclosure. It should be recognized, however, that such description is not intended as a limitation on the scope of the present disclosure. Rather, the description also encompasses combinations and modifications to those exemplary aspects described herein.

[0054] In general, in some aspects, the present disclosure is directed to hybrid lens optical imaging systems. Hybrid lens optical imaging systems combine conventionalrefractive lens elements with meta-optical element structures. In some cases, these systems may provide enhanced imaging performance while achieving reduced module dimensions compared to traditional multi-element refractive lens systems. The hybrid approach may leverage the optical power and chromatic aberration correction capabilities of refractive lenses while utilizing the compact form factor and design flexibility of meta-optical elements.

[0055] Meta-optical elements, also referred to as metalenses or meta-optical element structures, may comprise arrays of sub -wavelength features (also referred to as meta-atoms) patterned on substrates to manipulate light propagation. In some cases, these structures may provide optical functions such as focusing, beam steering, or aberration correction through the precise control of phase, amplitude, or polarization of incident light. The meta-atoms may, individually or collectively, interact with light waves. The meta-atoms may be subwavelength nanostructures, which indicates that the structures have lateral dimensions, parallel to the substrate surface, that are less than a wavelength of light that is to be incident on to the structures. For example, in some instances, the meta-atoms can be in the form of nanoscale features having dimensions less than 1 micron. When combined with refractive lens elements, meta-optical element structures may enable optical system designs that achieve performance levels comparable to conventional multi-element lens systems while occupying significantly less volume.

[0056] The integration of refractive and meta-optical elements may be accomplished through direct bonding techniques that eliminate air gaps between components. In some cases, this bonding approach may provide manufacturing advantages by reducing the number of discrete components and assembly steps compared to traditional lens mounting methods. The direct bonding may also contribute to improved mechanical stability and reduced sensitivity to environmental factors such as temperature variations and mechanical shock.

[0057] Hybrid lens optical imaging systems may achieve compact module designs through the elimination of traditional barrel mounting structures. In some cases, the barrel- free approach may enable smaller footprint designs by allowing components to be stacked and bonded directly together without the need for separate mechanical housing elements. This approach may reduce the overall module height and cross-sectional area while maintaining optical alignment between components. The elimination of barrel structures may also reduce the number of sources that adversely affect manufacturing tolerances and assembly precision, potentially improving manufacturing yield and optical performance consistency.

[0058] The hybrid lens approach may be particularly suitable for applications where space constraints limit the use of conventional multi-element refractive lens systems. Examples of hybrid lens optical imaging systems include camera modules, microscope modules, barcode readers, among other types of imaging systems. In some cases, these systems may achieve total track length to image sensor circle diameter ratios that approach or fall below unity, representing a level of compactness that may be difficult to achieve with purely refractive designs. The combination of refractive and meta-optical elements may also provide design flexibility for optimizing specific optical parameters such as field of view, resolution, and chromatic aberration correction for particular application requirements.

[0059] FIG. 1 is a schematic of an example hybrid lens optical imaging system. In particular, the optical imaging system of FIG. 1 is a hybrid lens camera module 100. However, the optical systems disclosed herein are not limited to camera modules and can include other optical systems, such as, e.g., microscope modules, barcode readers, among other systems, and any description herein of the camera module 100 may also apply to those other systems. The optical systems can be standalone or can form part of larger systems such as, e.g., medical devices (e.g., endoscopy cameras), augmented reality (AR) systems, virtual reality (VR) systems, mixed reality (MR) systems. The optical systems disclosed herein can be included in eyeglasses, mirrors (e.g., rearview mirrors), or windows (e.g., windshields).

[0060] The hybrid lens camera module 100 comprises a combination of refractive and meta-optical components arranged to provide compact optical imaging functionality. The hybrid lens camera module 100 may integrate a refractive lens 104 with a meta-optical element stack 102 to achieve optical performance comparable to conventional multi-element lens systems while occupying reduced volume. In some cases, the hybrid lens camera module 100 may eliminate traditional barrel mounting structures, enabling a barrel-free module design that contributes to a smaller footprint compared to conventional lens assemblies. The direct integration of components in the hybrid lens camera module 100 may provide improved thermal stability compared to conventional lens systems through reduced mechanical interfaces and enhanced structural rigidity.

[0061] The refractive lens 104 may be configured to provide optical power and chromatic aberration correction. Although shown as rectangular in cross-section, the refractive lens 104 includes a curved front surface and a planar rear surface. For the purposes of this example, "front" is intended to mean a side or surface facing the direction from which light is incident, whereas "rear" is intended to mean a side or surface that is opposite to thefront. In some cases, the refractive lens 104 may be manufactured from plastic or glass materials similar to those used in smartphone camera applications. The curved front surface of the refractive lens 104 may be configured to collect and focus incident light, while the planar rear surface may facilitate direct bonding to subsequent optical components. The refractive lens 104 may contribute to the overall optical power of the hybrid lens camera module 100 while providing design flexibility for field of view and aberration correction optimization.

[0062] As further shown in FIG. 1, the meta-optical element stack 102 may comprise at least one meta-optical element structure disposed on a substrate to manipulate light propagation through sub -wavelength feature arrays. The meta-optical element stack 102 may provide optical functions such as focusing, beam steering, or aberration correction through precise control of phase, amplitude, or polarization characteristics of transmitted light. In some cases, the meta-optical element stack 102 may be configured as a meta-optical element stack comprising multiple meta-optical element structures arranged to enhance optical performance. The compact form factor of the meta-optical element stack 102 may enable reduced module dimensions while maintaining optical functionality comparable to conventional refractive elements.

[0063] An adhesive 106 may be positioned between the refractive lens 104 and the meta- optical element stack 102 to provide mechanical bonding and optical coupling. The adhesive 106 may comprise optically clear materials configured to minimize optical losses and maintain alignment between components. In some cases, the adhesive 106 may be applied using wafer-level bonding processes to achieve uniform thickness and minimize tilt tolerances. The planar rear surface of the refractive lens 104 may be bonded to a front side of the meta-optical element stack 102 through the adhesive 106, creating a mechanically stable interface that eliminates air gaps between components.

[0064] With continued reference to FIG. 1, a transparent cover layer 108 may be positioned between the meta-optical element stack 102 and an image sensor 112 to provide environmental protection and optical coupling. The transparent cover layer 108 may comprise glass or other optically transparent materials configured to transmit light while protecting underlying components from contamination or mechanical damage. A bonding adhesive and / or spacer 110 may be positioned between the meta-optical element stack 102 and the transparent cover layer 108 to maintain proper spacing and provide mechanical attachment. In some cases, a rear side of the meta-optical element stack 102 may be bonded to the imagesensor 112 through the transparent cover layer 108 and associated bonding materials. In the context of the present application, optically transparent indicates that the material is optically transparent for a specified operational wavelength (e.g., in the infra-red, short-range infrared (SWIR) UV, or visible part of the spectrum). The hybrid lens optical imaging systems of the present disclosure may be illuminated using either active illumination and / or passive illumination. Active illumination includes illuminating with light from light sources such as one or more lasers, one or more light emitting diodes, or other artificial light sources. In some cases, the artificial light sources may be included as part of the hybrid lens optical imaging systems described herein. Passive illumination includes light from ambient sources. Passive illumination may be modified by the hybrid lens optical imaging systems of the present disclosure by including one or more bandpass filters within the hybrid lens optical imaging system.

[0065] The image sensor 112 may comprise a photodetector array configured to convert incident optical radiation into electrical signals for image formation. An image sensor active area 114 may define the light-sensitive region of the image sensor 112 where photon detection occurs. The refractive lens and the meta-optical element stack together provide an image circle that is located at the same plane as the image sensor active area 114. The image circle at the plane of the image sensor active area 114 can include a maximum image circle diameter 122 that corresponds to the maximum dimension of the image sensor active area 114 within which the image maintains a defined optical quality and sufficient illumination without significant shading or distortion. The maximum image circle diameter 122 can, in some implementations, be larger than the maximum dimension of the image sensor active area 114. For instance, if the image sensor active area 114 is a square region with a side of length, / ., the maximum image circle diameter 122 can be larger than L. Generally, the maximum image circle is designed to be at the same plane as the image sensor active area 114. The image sensor 112 can include, e.g., an array of pixels, each including light sensitive elements, e.g., silicon photodiodes. In some cases, the image sensor 112 may be configured to detect light across specific wavelength ranges depending on the intended application of the hybrid lens camera module 100. In particular, examples, the image sensor 112 may be configured to detect light as specified operational wavelengths or wavelength ranges, such as infrared, ultraviolet, and / or the visible part of the electromagnetic spectrum. The bandwidth of wavelengths that the image sensor 112 is designed to sense can be, e.g., ±10 nm, ±20 nm, or ±50 nm. A die attach adhesive 116 may secure the image sensor 112 to thetransparent cover layer 108 or other mounting structures within the hybrid lens camera module 100. Although components such as filters, spacers, cover glass, die attach pads, among other components, may be shown in the example of FIG. 1 and other examples in the present disclosure as being separate from the meta-optical element stack, those components may alternatively be understood to be a part of the meta-optical element stack.

[0066] An absorptive coating 118 may be applied to selected surfaces within the hybrid lens camera module 100 to reduce stray light and improve optical contrast. The absorptive coating 118 may comprise materials configured to absorb light at wavelengths corresponding to the operational spectrum of the image sensor 112. In some cases, the absorptive coating 118 may extend along sidewalls of the hybrid lens camera module 100 to prevent unwanted light paths that could degrade image quality. For instance, the absorptive coating 118 may extend along side and / or front surfaces of the meta-optical element stack 102, and / or along the side surfaces of the cover layer 108, the image sensor 112, the spacer 110, and / or the die attachment pads 116. The absorptive coating 118 may contribute to improved optical performance by reducing internal reflections and scattered light within the module assembly. In some implementations, as described herein, the absorptive coating 118 may be designed to form one or more aperture stops (also referred to as apertures) for the hybrid lens optical imaging system. The apertures may be located at one or more interfaces within the optical imaging system, such as interfaces within the meta-optical element stack, at an interface between the refractive lens and the meta-optical element stack, at a rear surface of the meta- optical element stack, and / or on the cover slip layer of the system. Other locations for the apertures are also possible. In some implementations, the absorptive coating 118 may form additional baffles to block stray light into the hybrid lens optical imaging system. For instance, the coating 118 may form baffles on a front surface of the meta-optical element stack, but outside of the region where the refractive lens is bonded to the stack to prevent stray light from entering the refractive lens. In some implementations, the absorptive coating can be designed to have a predefined absorption response to block unwanted light leakage paths within the main wavelength range of the imaging system.

[0067] A total track length (TTL) 120 may represent the geometric path length from the front surface of the refractive lens 104 to the image sensor active area 114 of the hybrid lens camera module 100. An image circle diameter 122 may correspond to the diameter of the circular image field projected onto the image sensor active area 114 by the optical system. In some cases, a ratio of the total track length 120 to the image circle diameter 122 may be equalto or less than 1.3, equal to or less than 1.0, equal to or less than 0.8, or equal to or less than 0.75, indicating a compact optical design. In some cases, the minimum ratio may be, e.g., 0.3, 0.4, 0.5, 0.6, 0.7, or 0.75. The relationship between the total track length 120 and the image circle diameter 122 may characterize the compactness of the hybrid lens camera module 100 compared to conventional lens systems, with lower ratios indicating more compact designs that may be suitable for space-constrained applications.

[0068] The refractive lens 104 may be configured in various shapes and geometries to optimize optical performance for different application requirements. In some cases, the shape of the refractive lens 104 may be selected based on factors such as desired optical power, field of view characteristics, and manufacturing considerations. The curved front surface and planar rear surface configuration of the refractive lens 104 may enable direct bonding to the meta-optical element stack 102 while providing the optical functionality needed for the hybrid lens camera module 100. Different refractive lens shapes may offer varying degrees of design flexibility and manufacturing complexity, allowing system designers to balance optical performance with cost and production requirements. The refractive lenses of the present disclosure refractive lens can be made of varying glass or plastics and have a center thickness of, e.g., greater than or equal to 0.15 mm and edge thicknesses of, e.g., greater than or equal to 0.1 mm.

[0069] FIG. 2A illustrates a meniscus-shaped refractive lens 202 according to some implementations. The meniscus-shaped refractive lens 202 may represent a particular example of the refractive lens 104 configured with specific surface curvatures to provide optical power and aberration correction. In some cases, the meniscus-shaped refractive lens 202 may comprise a curved front surface that may be convex and a planar rear surface that surrounds a concave rear surface. The convex front surface of the meniscus-shaped refractive lens 202 may be configured to collect and focus incident light, while the concave rear surface may contribute to the overall optical power distribution of the lens element. The planar rear surface surrounding the concave rear surface may facilitate direct bonding to subsequent optical components through adhesive attachment methods.

[0070] The meniscus-shaped refractive lens 202 may be manufactured from plastic or glass materials similar to common lenses used in smartphone camera applications. In some cases, the front surface of the meniscus-shaped refractive lens 202 may be configured as spherical surface to provide fewer degrees of freedom compared to aspheric designs while potentially offering lower manufacturing cost. The spherical surface configuration maysimplify the manufacturing process while still providing optical functionality suitable for many imaging applications. The meniscus shape may provide design flexibility for controlling optical aberrations and field curvature characteristics within the hybrid lens camera module 100.

[0071] FIG. 2B illustrates a planoconvex-shaped refractive lens 204 according to some implementations. The planoconvex-shaped refractive lens 204 may represent another particular example of the refractive lens 104 configured with a simplified surface geometry for specific optical applications. In some cases, the planoconvex-shaped refractive lens 204 may comprise a curved front surface that may be a convex surface and a planar rear surface, in which the entire rear surface is planar, in contrast to the partially concave rear surface design of lens 202. The convex front surface of the planoconvex-shaped refractive lens 204 may provide optical power for focusing incident light, while the planar rear surface may enable direct bonding to the meta-optical element stack 102 without the geometric complexity of the meniscus configuration. The planoconvex design may offer manufacturing advantages through the elimination of the concave rear surface found in meniscus configurations. For instance, the planoconvex design may allow the refractive lens to be bonded to the meta-optical element stack 102 such that there is no gap (e.g., no air gap) between the lens and the meta-optical element stack.

[0072] The planoconvex-shaped refractive lens 204 may be manufactured from plastic or glass materials similar to those used in smartphone camera applications, providing material compatibility with existing optical manufacturing processes. In some cases, the front surface of the planoconvex-shaped refractive lens 204 may be configured as a spherical surface to reduce manufacturing complexity and cost compared to aspheric surface designs. The spherical surface approach may provide adequate optical performance for applications where the reduced degrees of freedom are acceptable for the intended optical specifications.

[0073] FIG. 3 illustrates a hybrid lens camera module 300 according to some implementations. The hybrid lens camera module 300 may represent a particular example of a hybrid lens optical imaging system that demonstrates specific structural arrangements and component configurations for achieving compact optical performance. In some cases, the hybrid lens camera module 300 may incorporate multiple meta-optical element structures arranged in a stacked configuration to enhance optical functionality while maintaining reduced module dimensions. The hybrid lens camera module 300 may provide design flexibility for optimizing optical parameters such as aberration correction, field of viewcharacteristics, and chromatic performance through the strategic placement of refractive and meta-optical components.

[0074] The hybrid lens camera module 300 comprises a refractive lens 304 configured to provide optical power and / or chromatic aberration correction functionality. The refractive lens 304 may be configured in a meniscus shape comprising a convex front surface and a combined planar and concave rear surface, or alternatively may be configured as a planoconvex lens comprising a convex front surface and a planar rear surface. In some cases, the flat part of the rear surface of the refractive lens 304 may be attached or bonded directly to the meta-optical element stack through adhesive bonding techniques. The center of the refractive lens 304 may be aligned optically or mechanically to the center of an aperture on the first surface of the subsequent meta-optical element stack, where the aperture may be defined by an opening in an absorptive coating 118. This alignment configuration may contribute to optical performance optimization and manufacturing precision within the hybrid lens camera module 300.

[0075] The hybrid lens camera module 300 includes a first substrate 301 that may serve as a mounting platform for meta-optical element structures within the optical stack. The first substrate 301 may be manufactured from flat glass wafers, such as D263T glass to provide mechanical stability and optical transparency for the meta-optical components. In some cases, the first substrate 301 may be configured to support meta-optical element structures on one or both surfaces depending on the specific optical design requirements. The first substrate 301 may contribute to the overall structural integrity of the hybrid lens camera module 300 while providing a stable platform for precise meta-optical element fabrication and alignment.

[0076] A first meta-optical element structure 303 may be disposed on the first substrate 301 to provide optical functionality through sub -wavelength feature arrays. The first meta- optical element structure 303 may be positioned on a surface of the first substrate 301 that faces away from the refractive lens 304, enabling specific optical phase and amplitude control characteristics. The first meta-optical element structure 303 may contribute to the overall optical performance of the hybrid lens camera module 300 by providing focusing, beam steering, or aberration correction functionality that complements the optical characteristics of the refractive lens 304.

[0077] The hybrid lens camera module 300 incorporates an adhesive 106 positioned between the refractive lens 304 and the first substrate 301 to provide mechanical bonding andoptical coupling. The adhesive 106 may comprise optically clear materials configured to maintain optical transmission while providing structural attachment between components. The adhesive 106 may enable direct bonding of the refractive lens 304 to the meta-optical element stack and / or to the absorptive coating 118. When a meniscus-type refractive lens 304 is used, the concave rear surface may create a gap (e.g., an air gap) 306 between the refractive lens 304 and the substrate 301 of the meta-optical element stack.

[0078] A first spacer 305 may be positioned between the first substrate 301 and subsequent optical components to maintain proper spacing and provide mechanical separation. The first spacer 305 may be configured to create an additional gap 311 (e.g., an air gap) between meta-optical element structures, enabling specific optical path and geometric path length control and component isolation. In some cases, the first spacer 305 may be manufactured from materials that provide mechanical stability while maintaining optical transparency or absorption characteristics depending on the intended optical function. The first spacer 305 may contribute to the overall optical design flexibility of the hybrid lens camera module 300 by enabling precise control of spacing between meta-optical components.

[0079] The hybrid lens camera module 300 includes a second substrate 307 that may provide additional mounting capability for meta-optical element structures within the optical stack. The second substrate 307 may be manufactured from flat glass wafers similar to the first substrate 301, providing consistent material properties and processing compatibility. In some cases, the second substrate 307 may be positioned between the first substrate 301 and the image sensor 112 to enable multi-layer meta-optical element configurations. The second substrate 307 may be directly bonded to the first substrate 301 without an air gap, or alternatively may be separated by spacer structures 305 to create controlled gaps depending on the specific optical design requirements. The substrates of the meta-optical element stacks described herein may have varying thickness. For example, in some implementations, the substrates (e.g., substrate 301 and substrate 307) can be at least 0.1 mm thick to up to several mm thick (as determined along the geometric path length of the imaging system).

[0080] A second meta-optical element structure 309 may be disposed on the second substrate 307 to provide additional optical functionality within the meta-optical element stack. The second meta-optical element structure 309 may be positioned on a surface of the second substrate 307 that faces away from the refractive lens 304, enabling complementary optical characteristics to the first meta-optical element structure 303. In some cases, the second meta-optical element structure 309 may be configured to work in combination withthe first meta-optical element structure 303 to achieve optical performance levels comparable to conventional multi-element refractive lens systems. The positioning of the second meta- optical element structure 309 may enable enhanced aberration correction, improved field of view characteristics, or optimized chromatic performance depending on the specific design parameters of the hybrid lens camera module 300.

[0081] The hybrid lens camera module 300 incorporates a bonding adhesive and / or spacer 110 positioned between the second substrate 307 and the transparent cover layer 108 to maintain proper component spacing and mechanical attachment. The bonding adhesive and / or spacer 110 may create a gap between the second meta-optical element structure 309 and the transparent cover layer 108, or alternatively may provide direct bonding without a gap depending on the optical design requirements. In some cases, the distance between the second meta-optical element structure 309 and the transparent cover layer 108 may be optimized to achieve specific optical path and geometric path length characteristics or to accommodate additional optical components such as bandpass filters or anti-reflection coatings. The bonding adhesive and / or spacer 110 may contribute to the mechanical stability of the hybrid lens camera module 300 while enabling design flexibility for optical performance optimization.

[0082] The absorptive coating 118 may be applied to selected surfaces within the hybrid lens camera module 300 to define aperture characteristics and reduce stray light propagation. In some cases, the absorptive coating 118 may be used to define an aperture that may be located between the refractive lens 304 and the meta-optical element stack, providing control over the numerical aperture and light collection characteristics of the optical system. The absorptive coating 118 may comprise materials such as black chrome that provide high absorption coefficients at the operational wavelengths of the hybrid lens camera module 300. The aperture defined by the absorptive coating 118 may be configured as a circular opening that enables precise control of light propagation while reducing unwanted optical effects such as internal reflections or scattered light that could degrade image quality.

[0083] Additional flat substrates may be integrated into the meta-optical element stack of the hybrid lens camera module 300 to provide enhanced optical functionality. In some cases, these additional substrates may include bandpass filters configured to selectively transmit specific wavelength ranges while blocking unwanted spectral components. Anti-reflection coatings may also be integrated into the stack to reduce optical losses and improve transmission efficiency at component interfaces. The integration of additional flat substratesmay enable the hybrid lens camera module 300 to achieve specialized optical characteristics such as spectral filtering, polarization control, or enhanced transmission efficiency depending on the specific application requirements. The modular nature of the substrate stack configuration may provide design flexibility for customizing optical performance while maintaining the compact form factor advantages of the hybrid lens approach.

[0084] FIG. 4A illustrates a hybrid lens camera module 400 according to some implementations. The hybrid lens camera module 400 may represent a particular example of a hybrid lens optical imaging system that demonstrates a fully bonded structure configuration where meta-optical element components are directly bonded together without gaps between elements of the meta-optical element stack. In some cases, the hybrid lens camera module 400 may provide enhanced mechanical stability, reduced tolerance sensitivity, and reduced size compared to configurations that incorporate air gaps or spacer elements between meta- optical components. The fully bonded approach of the hybrid lens camera module 400 may enable improved thermal stability and manufacturing precision through the elimination of discrete spacing elements that could introduce alignment variations or thermal expansion mismatches. The direct bonding configuration may also contribute to reduced module complexity and decreased TTL 120 to image circle diameter 122 ratio by reducing the number of separate components and assembly steps compared to traditional lens mounting approaches.

[0085] The hybrid lens camera module 400 comprises a refractive lens 404 configured to provide optical power and chromatic aberration correction functionality within the optical system. The refractive lens 404 may be configured in a meniscus shape comprising a convex front surface and a combined planar and concave rear surface arrangement, or alternatively may be configured as a planoconvex lens comprising a convex front surface and a planar rear surface. In some cases, the refractive lens 404 may be manufactured from plastic materials using injection molding processes that enable aspheric surface geometries for enhanced optical performance. The refractive lens 404 may also be manufactured from glass materials using diamond turning processes that may provide spherical surface configurations for reduced manufacturing complexity and cost. The planar rear surface portion of the refractive lens 404 may facilitate direct bonding to the meta-optical element stack through adhesive attachment methods that eliminate air gaps at the bonding interface.

[0086] The hybrid lens camera module 400 incorporates a first substrate 401 that may serve as a mounting platform for meta-optical element structures within the fully bondedoptical stack. The first substrate 401 may be manufactured from flat glass wafers, such as D263T glass, to provide mechanical stability and optical transparency for meta-optical components. In some cases, the first substrate 401 may be configured to support meta-optical element structures on one or both surfaces depending on the specific optical design requirements of the hybrid lens camera module 400.

[0087] A first meta-optical element structure 403 may be disposed on the first substrate 401 to provide optical functionality through sub -wavelength feature arrays that manipulate light propagation characteristics. The first meta-optical element structure 403 may be positioned on a surface of the first substrate 401 that faces away from the refractive lens 404, enabling specific optical phase and amplitude control characteristics within the optical path. In some cases, the first meta-optical element structure 403 may be fabricated using lithographic processes that create precise sub -wavelength patterns on the first substrate 401 surface. The first meta-optical element structure 403 may contribute to the overall optical performance of the hybrid lens camera module 400 by providing focusing, beam steering, and / or aberration correction functionality that complements the optical characteristics of the refractive lens 404. The positioning of the first meta-optical element structure 403 on the surface facing away from the refractive lens 404 may enable optimized optical path configurations while facilitating the direct bonding approach used in the hybrid lens camera module 400.

[0088] The hybrid lens camera module 400 includes a second substrate 405 that may provide additional mounting capability for meta-optical element structures within the fully bonded optical stack configuration. The second substrate 405 may be manufactured from flat glass wafers similar to the first substrate 401, providing consistent material properties and thermal expansion compatibility. In some cases, the second substrate 405 may be directly bonded to the first substrate 401 without a gap between the substrates, creating a mechanically stable interface that eliminates potential sources of alignment variation or thermal expansion mismatch. The direct bonding between the first substrate 401 and the second substrate 405 may be achieved using wafer-level bonding processes that create uniform interfaces with minimal thickness variation. The second substrate 405 may be positioned to enable multi-layer meta-optical element configurations while maintaining the compact form factor advantages of the fully bonded structure approach used in the hybrid lens camera module 400.

[0089] A second meta-optical element structure 407 may be disposed on the second substrate 405 to provide additional optical functionality within the meta-optical element stack of the hybrid lens camera module 400. The second meta-optical element structure 407 may be positioned on a surface of the second substrate 405 that faces away from the refractive lens 404, enabling complementary optical characteristics to the first meta-optical element structure 403. In some cases, the second meta-optical element structure 407 may be configured to work in combination with the first meta-optical element structure 403 to achieve optical performance levels comparable to conventional multi-element refractive lens systems while maintaining the compact dimensions enabled by the meta-optical approach. The second meta-optical element structure 407 may be fabricated using similar lithographic processes as the first meta-optical element structure 403, providing consistent manufacturing approaches and material compatibility. The positioning of the second meta-optical element structure 407 may enable enhanced aberration correction, improved field of view characteristics, and / or optimized chromatic performance depending on the specific design parameters of the hybrid lens camera module 400.

[0090] The hybrid lens camera module 400 may incorporate one or more additional optical elements 409, such as a bandpass filter, that may be integrated into the optical path to provide enhanced spectral control or filtering functionality. The one or more additional optical elements 409 may be positioned between meta-optical components or integrated directly onto substrate surfaces to provide wavelength-selective transmission characteristics. In some cases, the one or more additional optical elements 409 may comprise bandpass filters configured to selectively transmit specific wavelength ranges while blocking unwanted spectral components that could degrade optical performance. The integration of the one or more additional optical elements 409 into the fully bonded structure of the hybrid lens camera module 400 may enable specialized optical characteristics while maintaining the mechanical stability and compact form factor advantages of the direct bonding approach. The one or more additional optical elements 409 may also include anti-reflection coatings or other optical treatments that enhance transmission efficiency and reduce optical losses at component interfaces within the hybrid lens camera module 400.

[0091] FIG. 4B illustrates a hybrid lens camera module 450 according to some implementations. The hybrid lens camera module 450 may represent a particular example of a hybrid lens optical imaging system in which an aperture stop 457 may be positioned at an interface between bonded meta-optical components. In some cases, the hybrid lens cameramodule 450 may provide enhanced optical control through the strategic placement of the aperture stop 457 within the meta-optical element stack, enabling precise management of light propagation characteristics while maintaining the compact form factor advantages of the hybrid lens approach. The hybrid lens camera module 450 may enable reduced total track length 120 to image circle diameter 122 ratios through the direct bonding approach that eliminates gaps between components while maintaining optical functionality comparable to conventional multi-element lens systems.

[0092] The hybrid lens camera module 450 comprises the refractive lens 404 configured to provide optical power and chromatic aberration correction functionality within the optical system. The refractive lens 404 may be configured in a meniscus shape comprising a convex front surface and a combined planar and concave rear surface arrangement that enables direct bonding to subsequent optical components. Alternatively, the refractive lens 404 may be configured as a planoconvex lens comprising a convex front surface and a planar rear surface that facilitates simplified bonding interfaces with the meta-optical element stack. In some cases, the refractive lens 404 may be manufactured from plastic materials using injection molding processes that enable aspheric surface geometries for enhanced optical performance, or alternatively may be manufactured from glass materials. The planar rear surface portion of the refractive lens 404 may facilitate direct bonding to the meta-optical element stack through the adhesive 106 that eliminates air gaps at the bonding interface while providing mechanical stability and optical coupling between components.

[0093] The hybrid lens camera module 450 incorporates a first substrate 453 that may serve as a mounting platform for meta-optical element structures within the optical stack configuration. The first substrate 453 may be manufactured from flat glass wafers to provide mechanical stability and optical transparency for meta-optical components while enabling precise fabrication of sub -wavelength feature arrays. In some cases, the first substrate 453 may be configured to support meta-optical element structures on surfaces that face toward or away from the refractive lens 404 depending on the specific optical design requirements of the hybrid lens camera module 450.

[0094] A first meta-optical element structure 451 may be disposed on the first substrate 453 to provide optical functionality through sub -wavelength feature arrays that manipulate light propagation characteristics within the optical path. The first meta-optical element structure 451 may be positioned on a surface of the first substrate 453 that faces the refractive lens 404, enabling specific optical phase and amplitude control characteristics at a locationthat manipulates interaction with light transmitted through the refractive lens 404. In some cases, the first meta-optical element structure 451 may be fabricated using lithographic processes that create precise sub -wavelength patterns on the first substrate 453 surface, providing controlled optical functionality that complements the characteristics of the refractive lens 404. The first meta-optical element structure 451 may contribute to the overall optical performance of the hybrid lens camera module 450 by providing focusing, beam steering, and / or aberration correction functionality that works in combination with the aperture stop 457 to control light propagation.

[0095] The hybrid lens camera module 450 includes a second substrate 455 that may provide additional mounting capability for meta-optical element structures within the optical stack configuration that incorporates the aperture stop 457. The second substrate 455 may be manufactured from flat glass wafers similar to the first substrate 453, providing consistent material properties and thermal expansion compatibility throughout the meta-optical element stack. In some cases, the second substrate 455 may be directly bonded to the first substrate 453 with the aperture stop 457 positioned at the interface between the substrates, creating a mechanically stable configuration that eliminates potential sources of alignment variation while providing precise aperture control. The direct bonding between the first substrate 453 and the second substrate 455 may be achieved using wafer-level bonding processes that create uniform interfaces with minimal thickness variation, contributing to the compact form factor of the hybrid lens camera module 450.

[0096] The aperture stop 457 may be positioned between the first substrate 453 and the second substrate 455 at the interface between the bonded meta-optical components to provide precise control over light propagation characteristics. The aperture stop 457 may be formed using the absorptive coating 118, such as black chrome or other materials that provide high absorption coefficients at the operational wavelengths of the hybrid lens camera module 450. In some cases, the aperture stop 457 may be configured as a circular opening that enables controlled light transmission while blocking unwanted light paths that could degrade optical performance through internal reflections or scattered light.

[0097] A second meta-optical element structure 459 may be disposed on the second substrate 455 to provide additional optical functionality within the meta-optical element stack of the hybrid lens camera module 450. The second meta-optical element structure 459 may be positioned on a rear surface of the second substrate 455 that faces away from the refractive lens 404, enabling complementary optical characteristics to the first meta-optical elementstructure 451 while working in combination with the aperture stop 457 configuration. In some cases, the second meta-optical element structure 459 may be configured to work in combination with the first meta-optical element structure 451 and the aperture stop 457 to achieve optical performance levels comparable to conventional multi-element refractive lens systems while maintaining compact dimensions. The second meta-optical element structure 459 may be fabricated using similar lithographic processes as the first meta-optical element structure 451, providing consistent manufacturing approaches and material compatibility throughout the meta-optical element stack.

[0098] The hybrid lens camera module 450 may incorporate the one or more additional optical elements 409, such as bandpass filters, that may be integrated into the optical path to provide enhanced spectral control or filtering functionality while working in combination with the aperture stop 457 configuration.

[0099] FIG. 5A illustrates a hybrid lens camera module 500 according to some implementations. The hybrid lens camera module 500 may represent a particular example of a hybrid lens optical imaging system that demonstrates a double-sided meta-optical element configuration where meta-optical element structures may be manufactured on opposite sides of a single glass substrate or wafer. In some cases, the hybrid lens camera module 500 may provide enhanced manufacturing efficiency and reduced component count compared to configurations that utilize separate substrates for each meta-optical element structure. The double-sided approach of the hybrid lens camera module 500 may enable compact optical designs while maintaining the optical functionality and performance characteristics comparable to multi-substrate configurations. The hybrid lens camera module 500 may contribute to reduced total track length 120 to image circle diameter 122 ratios through the elimination of additional substrate layers and associated bonding interfaces that could increase overall module thickness.

[0100] The hybrid lens camera module 500 comprises a refractive lens 504 configured to provide optical power and chromatic aberration correction functionality within the optical system. The refractive lens 504 may be configured in a meniscus shape comprising a convex front surface and a combined planar and concave rear surface arrangement that enables direct bonding to subsequent optical components through planar surface regions. Alternatively, the refractive lens 504 may be configured as a planoconvex lens comprising a convex front surface and a planar rear surface that facilitates simplified bonding interfaces with the meta- optical element stack. In some cases, the refractive lens 504 may be manufactured fromplastic materials using injection molding processes that enable aspheric surface geometries for enhanced optical performance, or alternatively may be manufactured from glass materials using diamond turning processes.

[0101] The hybrid lens camera module 500 optionally incorporates a lens spacer 508 positioned between the refractive lens 504 and the meta-optical element stack to provide controlled spacing and mechanical attachment functionality. The lens spacer 508 may be configured to maintain precise optical path and geometric path length characteristics while enabling direct bonding between the refractive lens 504 and the meta-optical element stack. In some cases, the flat surface of the refractive lens 504 may be directly bonded to the lens spacer 508 through adhesive bonding techniques that eliminate air gaps at the bonding interface. The lens spacer 508 may be directly bonded to the meta-optical element stack, creating a mechanically stable configuration that reduces tolerance variations and assembly complexity compared to configurations that utilize separate mounting structures.

[0102] The hybrid lens camera module 500 includes a first substrate 503 that may serve as a mounting platform for meta-optical element structures within the double-sided configuration. The first substrate 503 may be manufactured from flat glass wafers, such as D263T glass, to provide mechanical stability and optical transparency for meta-optical components fabricated on both surfaces. In some cases, the first substrate 503 may be configured to support meta-optical element structures on both the front and rear surfaces, enabling the double-sided configuration that reduces the number of separate substrate components compared to multi -substrate approaches. The single substrate approach of the first substrate 503 may enable simplified manufacturing processes and reduced assembly complexity while maintaining optical performance comparable to multi -substrate configurations.

[0103] A first meta-optical element structure 501 may be disposed on a first side of the first substrate 503 to provide optical functionality through sub -wavelength feature arrays that manipulate light propagation characteristics. The first meta-optical element structure 501 may be positioned on a surface of the first substrate 503 that faces the refractive lens 504, enabling specific optical phase and amplitude control characteristics at a location that directly interacts with light transmitted through the refractive lens 504. In some cases, the first meta-optical element structure 501 may be fabricated using lithographic processes that create precise subwavelength patterns on the first substrate 503 surface, providing controlled optical functionality that complements the characteristics of the refractive lens 504. The first meta-optical element structure 501 may contribute to the overall optical performance of the hybrid lens camera module 500 by providing focusing, beam steering, and / or aberration correction functionality that works in combination with the second meta-optical element structure to achieve enhanced optical characteristics. The positioning of the first meta-optical element structure 501 on the surface facing the refractive lens 504 may enable optimized light collection and initial optical processing within the double-sided substrate configuration.

[0104] A second meta-optical element structure 505 may be disposed on a second opposite side of the first substrate 503 to provide additional optical functionality within the double-sided meta-optical element configuration. The second meta-optical element structure 505 may be positioned on the rear surface of the first substrate 503 that faces away from the refractive lens 504, enabling complementary optical characteristics to the first meta-optical element structure 501 while utilizing the same substrate platform. The second meta-optical element structure 505 may be fabricated using similar lithographic processes as the first meta-optical element structure 501, providing consistent manufacturing approaches and material compatibility throughout the double-sided configuration. The double-sided arrangement of the first meta-optical element structure 501 and the second meta-optical element structure 505 on the first substrate 503 may enable enhanced aberration correction, improved field of view characteristics, and optimized chromatic performance while reducing the overall component count and assembly complexity of the hybrid lens camera module 500.

[0105] An additional spacer 507 may be positioned within the optical path of the hybrid lens camera module 500 to provide additional spacing control and component separation functionality. The spacer 507 may work in combination with the lens spacer 508, enabling specific optical path and geometric path length control and component isolation within the meta-optical element stack.

[0106] The absorptive coating 118 may be designed to form an aperture on or within the meta-optical element stack, providing precise control over light propagation characteristics and numerical aperture definition. A meta-optical element structure, such as meta-optical element structure 501 may be formed within the aperture defined by the absorptive coating 118, whether at a front surface of the stack or at an interface within the stack, enabling integrated aperture and optical functionality within a single component configuration.

[0107] The direct bonding approach utilized throughout the hybrid lens camera module 500 may contribute to reduced total track length 120 to image circle diameter 122 ratios,providing a more compact design without substantial loss in quality of optical performance compared to conventional lens systems. The elimination of air gaps between directly bonded components may reduce overall module thickness while maintaining mechanical stability and optical alignment precision. In some cases, the direct bonding of the lens spacer 508 to both the refractive lens 504 and the meta-optical element stack may create a mechanically integrated assembly that reduces tolerance accumulation and assembly variations. The double-sided meta-optical element configuration on the first substrate 503 may further contribute to compactness by eliminating the need for additional substrate layers and associated bonding interfaces that could increase module dimensions.

[0108] FIG. 5B illustrates a hybrid lens camera module 550 according to some implementations. The hybrid lens camera module 550 may represent a particular example of a hybrid lens optical imaging system that demonstrates a configuration where a meta-optical element structure may be fabricated directly on the sensor cover glass instead of using a separate substrate. In some cases, the hybrid lens camera module 550 may provide enhanced integration and reduced component count compared to configurations that utilize separate substrates for all meta-optical element structures. The direct fabrication approach of the hybrid lens camera module 550 may enable simplified manufacturing processes while maintaining optical performance characteristics comparable to multi -substrate configurations. The hybrid lens camera module 550 may contribute to reduced total track length 120 to image circle diameter 122 ratios through the elimination of additional substrate layers and associated bonding interfaces that could increase overall module thickness.

[0109] The hybrid lens camera module 550 comprises the refractive lens 504 configured to provide optical power and chromatic aberration correction functionality within the optical system. The refractive lens 504 may be configured in a meniscus shape comprising a convex front surface and a combined planar and concave rear surface arrangement that enables direct bonding to subsequent optical components through planar surface regions. Alternatively, the refractive lens 504 may be configured as a planoconvex lens comprising a convex front surface and a planar rear surface that facilitates simplified bonding interfaces with the meta- optical element stack. In some cases, the refractive lens 504 may be manufactured from plastic materials using injection molding processes that enable aspheric surface geometries for enhanced optical performance, or alternatively may be manufactured from glass materials. The planar rear surface portion of the refractive lens 504 may facilitate direct bonding to themeta-optical element stack through the adhesive 106 that eliminates air gaps at the bonding interface while providing mechanical stability and optical coupling between components.

[0110] The hybrid lens camera module 550 includes a first substrate 551 that may serve as a mounting platform for meta-optical element structures within the optical stack configuration. The first substrate 551 may be manufactured from flat glass wafers. In some cases, the first substrate 551 may be configured to support meta-optical element structures on surfaces that face toward or away from the refractive lens 504 depending on the specific optical design requirements of the hybrid lens camera module 550.[OHl] A first meta-optical element structure 553 may be disposed on the first substrate 551 to provide optical functionality through sub -wavelength feature arrays that manipulate light propagation characteristics within the optical path. The first meta-optical element structure 553 may be positioned on a surface of the first substrate 551 that faces to or away from the refractive lens 504, enabling specific optical phase and amplitude control characteristics at a location that processes light transmitted through the refractive lens 504. In some cases, the first meta-optical element structure 553 may be fabricated using lithographic processes that create precise sub -wavelength patterns on the first substrate 551 surface, providing controlled optical functionality that complements the characteristics of the refractive lens 504. The first meta-optical element structure 553 may contribute to the overall optical performance of the hybrid lens camera module 550 by providing focusing, beam steering, and / or aberration correction functionality that works in combination with the second meta-optical element structure to achieve enhanced optical characteristics.

[0112] A second meta-optical element structure 557 may be disposed directly on the transparent cover layer 108 to provide additional optical functionality within the meta-optical element stack of the hybrid lens camera module 550. The second meta-optical element structure 557 may be positioned on a surface of the transparent cover layer 108 that faces the refractive lens 504 or on a surface that faces the image sensor 112. In some cases, the second meta-optical element structure 557 may be fabricated directly on the transparent cover layer 108 using lithographic processes that create precise sub -wavelength patterns, eliminating the need for a separate substrate and associated bonding interfaces. The second meta-optical element structure 557 may be configured to work in combination with the first meta-optical element structure 553 to achieve optical performance levels comparable to conventional multi-element refractive lens systems while maintaining compact dimensions through the sensor cover glass integration approach.

[0113] A spacer 555 may be positioned between the first substrate 551 and the transparent cover layer 108 to provide controlled spacing and mechanical attachment functionality within the sensor cover glass integration configuration. The spacer 555 may be configured to maintain precise optical path and geometric path length characteristics while enabling direct bonding between the first substrate 551 and the transparent cover layer 108. In some cases, the spacer 555 may be adjusted in height to accommodate the second meta- optical element structure 557 being formed directly on the transparent cover layer 108, providing design flexibility for optimizing optical path and geometric path lengths and component spacing. The spacer 555 may be manufactured from materials that provide mechanical stability while maintaining optical transparency or absorption characteristics depending on the intended optical function within the hybrid lens camera module 550. The height adjustment capability of the spacer 555 may enable precise control of the gap between the first substrate 551 and the transparent cover layer 108, contributing to the overall optical design flexibility of the hybrid lens camera module 550 while accommodating the integrated sensor cover glass approach.

[0114] FIG. 6 illustrates a table that shows performance parameters for three differently designed hybrid lens camera modules, where the primary difference between the designs may be represented by variations in total track length (TTL) measured in millimeters and the relationship to maximum image circle (MIC) diameter. The table demonstrates how optical performance characteristics may change as the total track length may be reduced from Design A through Design C, with Design A having a TTL of 2.00 mm, Design B having a TTL of 1.92 mm, and Design C having a TTL of 1.80 mm. The maximum image circle diameter remains constant at 1.80 mm across all three designs, enabling direct comparison of how TTL reduction affects various optical parameters. The table provides quantitative data for evaluating trade-offs between compactness and optical performance in hybrid lens camera module configurations.

[0115] As shown in the table, each sensor is designed to include 400x400 pixels with 3 pm pixel pitch, maintaining consistent detector characteristics for direct performance comparison. The spectral wavelength range of the incident light was specified to be 940±20 nm, which is in the near-infrared spectrum and is known to be a bandwidth suitable for specific imaging applications. The lens construction is specified as lP+2Meta for all designs, indicating a single plastic refractive element combined with two meta-optical elementstructures. The TTL / MIC ratio was decreased from 110% in Design A to 100% in Design C, quantifying the progression toward more compact optical configurations.

[0116] The table analyzes multiple performance parameters for the different designs, including modulation transfer function (MTF) measurements at half Nyquist frequency (Ny / 2), which serves as a measure of the optical system's ability to transfer contrast at different spatial frequencies from the object to the image plane. MTF describes how well detail from the object can be reproduced at the image plane, with higher MTF values indicating better preservation of image contrast and sharpness. As shown in the table, the MTF at Ny / 2 at the center field (OF) decreases from 0.78 in Design A to 0.68 in Design C, demonstrating the trade-off between reduced total track length and optical performance. The table alsos include MTF measurements at different field positions, such as 0.5F and 0.8F, showing both tangential and sagittal performance characteristics that vary across the field of view as the total track length is reduced.

[0117] The table also shows differences in optical distortion measurements between the three designs, with values presented for both itan 0 and JQ distortion models that characterize how well the optical system reproduces geometric relationships from object to image. Design A exhibits optical distortion values of -6.8 for flan Q and -5.2% for ff while Design C shows values of -6.9 and -5.8% respectively, indicating that distortion characteristics remain relatively stable across the different total track length configurations. Relative illumination measurements also vary between designs, with Design A showing 53% relative illumination compared to 50% for Design C, demonstrating how light collection efficiency changes as the total track length is reduced. The F-number increases from 2.11 in Design A to 2.28 in Design C, indicating that achieving more compact designs includes minor trade-offs in light gathering capability and depth of field characteristics. Field of view parameters were constant across designs, with diagonal field of view (DFOV) of 60° and horizontal and vertical field of view (HFOV and VFOV) of 42.5° each, demonstrating that the angular coverage was maintained despite variations in total track length.

[0118] FIGS. 7A, 7B, 8A, 8B, 9A, and 9B illustrate optical performance characteristics for the three hybrid lens camera module designs presented in the table of FIG. 6, providing detailed analysis of how variations in total track length affect modulation transfer function behavior across different measurement conditions. The plots demonstrate quantitative optical performance data that corresponds to Design A, Design B, and Design C configurations, enabling direct comparison of how the progressive reduction in total track length from 2.00mm to 1.80 mm influences optical transfer function characteristics. The optical performance data presented in these figures provides insight into the trade-offs between compact module design and optical quality that occur when implementing hybrid lens camera modules with different total track length to maximum image circle diameter ratios.

[0119] FIGS. 7 A and 7B correspond to Design A from the table of FIG. 6, which represents the hybrid lens camera module configuration with a total track length of 2.00 mm and a TTL / MIC ratio of 110%. FIG. 7A illustrates the modulus of the optical transfer function (OTF) versus spatial frequency measured in cycles per millimeter, showing how the optical system transfers contrast information across different spatial frequencies from the object plane to the image plane. The plot displays multiple curves representing different field angles at both sagittal and tangential planes, with the modulus of the OTF decreasing from approximately 1.0 at zero spatial frequency to lower values as spatial frequency increases toward the Nyquist frequency limit of approximately 167 cycles per millimeter. FIG. 7B presents the modulus of the optical transfer function versus focus shift measured in millimeters, demonstrating through-focus performance characteristics that show how optical performance varies as the focus position changes relative to the optimal focus plane. The through-focus curves in FIG. 7B exhibit peak performance near zero focus shift and demonstrate the depth of focus characteristics for different field angles, with the curves extending from approximately -0.05 to +0.05 millimeters focus shift range.

[0120] FIGS. 8A and 8B correspond to Design B from the table of FIG. 6, which represents the hybrid lens camera module configuration with a total track length of 1.92 mm and a TTL / MIC ratio of 107%. FIG. 8 A shows the modulus of the optical transfer function versus spatial frequency in cycles per millimeter for Design B, displaying performance characteristics that may be compared directly to the Design A results shown in FIG. 7A. The spatial frequency response curves in FIG. 8A demonstrate how the reduction in total track length from Design A to Design B affects contrast transfer capabilities across the spatial frequency range, with variations in the curve shapes and peak values reflecting the optical design modifications. FIG. 8B presents the through-focus modulation transfer function characteristics for Design B, showing how focus shift performance compares to the Design A configuration presented in FIG. 7B. The through-focus curves in FIG. 8B may exhibit different peak heights and curve widths compared to Design A, reflecting changes in depth of focus characteristics that result from the reduced total track length configuration. As can beseen from FIGS. 8A and 8B, there is little significant reduction in the performance of Design B relative to Design A.

[0121] FIGS. 9A and 9B correspond to Design C from the table of FIG. 6, which represents the most compact hybrid lens camera module configuration with a total track length of 1.80 mm and a TTL / MIC ratio of 100%. FIG. 9A illustrates the modulus of the optical transfer function versus spatial frequency for Design C, enabling direct comparison with the spatial frequency response characteristics shown in FIGS. 7A and 8A for Designs A and B respectively. The spatial frequency response curves in FIG. 9A demonstrate the optical performance characteristics achieved when the total track length approaches the maximum image circle diameter, showing how the most compact configuration affects contrast transfer capabilities across different field angles and spatial frequencies. FIG. 9B presents the through-focus modulation transfer function behavior for Design C, completing the series of through-focus performance comparisons that began with FIGS. 7B and 8B for Designs A and B. The through-focus characteristics in FIG. 9B may show variations in peak performance and focus tolerance compared to the less compact designs, reflecting the optical trade-offs associated with achieving the most compact TTL / MIC ratio of 100%. As can be seen from FIGS. 9A and 9B, there is little significant reduction in the performance of Design C relative to Designs A and B.

[0122] FIG. 10 is a schematic that illustrates an example method 1000 of fabricating a hybrid lens imaging system according to the present disclosure. The process 1000 of manufacturing a hybrid lens optical imaging system includes: providing (1002) a refractive lens having a curved front surface and a planar rear surface, a meta-optical element stack that includes a substrate and at least one meta-optical element structure on the substrate, and an image sensor having a maximum image circle diameter. The planar rear surface of the refractive lens is bonded (1004), e.g., directly bonded, to a front side the meta-optical element stack using an adhesive layer. A rear side of the meta-optical element stack is bonded (1006) to the image sensor. The refractive lens can be bonded to the meta-optical element stack first or the meta-optical element stack can be bonded to the image sensor first, or all three components can be bonded simultaneously. A ratio of a total track length of the hybrid lens optical imaging system (which is based on the geometric path length through the lens and meta-optical element stack to the image sensor surface) to the maximum image circle diameter of the image sensor may be designed to be equal to or less than 1.3, e.g., equal to or less than 1.0.

[0123] Bonding the components together may include applying an adhesive to the planar surface of the refractive lens and / or to a front surface of the meta-optical element stack. Bonding the components together may also include applying the adhesive to a cover glass that is positioned over the image sensor and / or to a rear surface of the meta-optical element stack. Other methods of performing bonding are also possible. The adhesive may be applied using, e.g., a spin-in technique or drop-dispensing technique. The adhesive may be cured using, e.g., a UV-based and / or thermally based process.

[0124] The thickness of the adhesives may be taken into account when designing the total track length of the optical imaging system. The thickness of the adhesives may be controlled in the stacking process or in a controlled pick-and-place process. If the adhesives are spun on, e.g., as in a wafer-based process, the thickness of the adhesives may be controlled by adjusting the spin speed and / or time. The adhesives may include a bonding glue that has a refractive index that matches refractive indices of one or more meta-optical elements, refractive lens, substrates, spacers, and / or cover glass used in the optical system. For example, the refractive index of the bonding adhesives may be between 1.3 and 1.7. In some implementations, the refractive index of the bonding adhesive deviates from the refractive index of the other components to which they are index matched by less than 0.2.

[0125] The meta-optical element stack may include one or more, or at least two meta- optical element structures disposed on separate substrates. Providing the meta-optical element stack can include directly bonding the separate substrates together, e.g., directly bonding the substrates together without a gap between them. Providing the meta-optical element stack can include providing an aperture stop. For example, providing the aperture stop can include forming and patterning an absorptive coating to create an opening on a surface of one of the substrates of the stack. The surface of the substrate on which the aperture is formed can include a front surface of a first substrate nearest to the refractive lens. Alternatively or in addition, the aperture can be formed at an interface between two substrates of the stack, or at a rear surface of the meta-optical element stack. In some implementations, the aperture can be centered around a meta-optical element structure between the refractive lens and the meta- optical element stack.

[0126] While this specification contains many specific implementation details, these should not be construed as limitations on the scope of any invention or on the scope of what may be claimed, but rather as descriptions of features that may be specific to particular implementations of particular inventions. Certain features that are described in thisspecification in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations, one or more features from a combination can in some cases be excised from the combination, and the combination may be directed to a subcombination or variation of a subcombination. A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. Accordingly, other implementations are within the scope of the following claims.

Claims

CLAIMS1. A hybrid lens optical imaging system, comprising: a refractive lens comprising a curved front surface and a planar rear surface; a meta-optical element stack comprising at least one meta-optical element structure disposed on a substrate, wherein the planar rear surface of the refractive lens is bonded to a front side of the meta-optical element stack; and an image sensor, wherein the refractive lens and the meta-optical element stack together provide a maximum image circle diameter that is greater than a maximum dimension of an image sensing area of the image sensor, wherein a rear side of the meta-optical element stack is bonded to the image sensor, wherein a ratio of a total track length of the hybrid lens optical imaging system to the maximum image circle diameter of the image sensor is less than 1.3.

2. The hybrid lens optical imaging system of claim 1, wherein the meta-optical element stack comprises at least two meta-optical element structures.

3. The hybrid lens optical imaging system of claim 2, wherein the at least two meta-optical element structures are disposed on separate substrates that are directly bonded together without an air gap.

4. The hybrid lens optical imaging system of claim 1, wherein the refractive lens comprises a meniscus-shaped lens, wherein the curved front surface is convex, and wherein the planar rear surface surrounds a concave rear surface of the refractive lens.

5. The hybrid lens optical imaging system of claim 4, comprising an adhesive layer, wherein the planar rear surface of the refractive lens is bonded directly to the meta-optical element stack through the adhesive layer.

6. The hybrid lens optical imaging system of claim 1, wherein the refractive lens comprises a planoconvex-shaped lens, wherein the curved front surface is a convex surface.

7. The hybrid lens optical imaging system of claim 6, comprising an adhesive layer, wherein the planar rear surface of the planoconvex-shaped lens is directly bonded to the meta-optical element stack through the adhesive layer.

8. The hybrid lens optical imaging system of any preceding claim, further comprising an aperture stop between the refractive lens and the meta-optical element stack.

9. The hybrid lens optical imaging system of claim 8, wherein a first meta-optical element structure is inside the aperture stop.

10. The hybrid lens optical imaging system of any of claims 1-7, wherein the meta-optical stack comprises an aperture stop, wherein the planar rear surface of the refractive lens is bonded directly to a first surface of the meta-optical stack, and wherein the aperture stop is located at a position that is different from the first surface of the meta-optical stack.

11. The hybrid lens optical imaging system of claim 10, wherein the meta-optical stack comprises a first substrate, wherein the planar rear surface of the refractive lens is bonded directly to a first surface of the first substrate, and wherein the aperture stop is located at a34second surface of the first substrate, the second surface being on an opposite side of the first substrate from the first surface of the first substrate.

12. The hybrid lens optical imaging system of any of claims 1-6, wherein the meta-optical stack comprises: a first substrate; a second substrate, wherein the first substrate is bonded to the second substrate; and a first meta-optical element structure on the first substrate; and a second meta-optical element structure on the second substrate.

13. The hybrid lens optical imaging system of claim 12, wherein the first meta-optical element structure is on a first surface of the first substrate that faces away from the refractive lens, and the second meta-optical element structure is on a first surface of the second substrate that faces away from the refractive lens.

14. The hybrid lens optical imaging system of claim 12, wherein the first meta-optical element structure is on a first surface of the first substrate that faces the refractive lens, and the second meta-optical element structure is on a first surface of the second substrate that faces away from the refractive lens.

15. The hybrid lens optical imaging system of claim 12, wherein the first meta-optical element structure is on a first surface of the first substrate that faces the refractive lens, and the second meta-optical element structure is on a first surface of the second substrate that faces the refractive lens.

16. The hybrid lens optical imaging system of claim 12, wherein the first meta-optical element structure is on a first surface of the first substrate that faces away from the refractive lens, and the second meta-optical element structure is on a first surface of the second substrate that faces the refractive lens.

17. The hybrid lens optical imaging system of claim 12, wherein the first substrate is separated from the second substrate by a spacer structure.

18. The hybrid lens optical imaging system of claim 1, wherein the meta-optical stack comprises: a first substrate; a first meta-optical element structure on a first side of the first substrate; and a second meta-optical element structure on a second opposite side of the first substrate.

19. The hybrid lens optical imaging system of any preceding claim comprising an outer light absorbing layer, wherein image sensor is configured to sense light having one or more wavelengths, and wherein the outer light absorbing layer is configured to absorb light having the one or more wavelengths.

20. The hybrid lens optical imaging system of claim 19, wherein the light absorbing layer extends from the imaging sensor, along sides of the meta-optical element stack to the refractive lens.

21. The hybrid lens optical imaging system of any preceding claim, wherein the rear side of the meta-optical element stack is directly bonded to the image sensor without an air gap.

22. The hybrid lens optical imaging system of any of claims 1-20, comprising a die attach adhesive on the image sensor, wherein the rear side of the meta-optical element stack is bonded to the image sensor via the die attach adhesive.

23. The hybrid lens optical imaging system of any of claims 1-20 and 22, comprising: a cover glass on the image sensor; and a die attach adhesive that bonds the cover glass to the image sensor; and an adhesive layer, wherein the rear side of the meta-optical element stack is bonded to the cover glass via the adhesive layer.

24. The hybrid lens optical imaging system of any of claims 1-20 and 22-23, comprising: a light filter layer between the meta-optical element stack and the image sensor.

25. The hybrid lens optical imaging system of any of claims 1-20 and 22-24, comprising: a spacer layer between the meta-optical element stack and the image sensor.

26. A method of manufacturing a hybrid lens optical imaging system, comprising: providing a refractive lens having a curved front surface and a planar rear surface; providing a meta-optical element stack comprising a substrate and at least one meta- optical element structure on the substrate; providing an image sensor; and directly bonding the planar rear surface of the refractive lens to a front side the meta- optical element stack using an adhesive layer; and bonding a rear side of the meta-optical element stack to the image sensor, wherein the refractive lens and the meta-optical element stack, when bonded to the image sensor, provide a maximum image circle diameter that is greater than a maximum dimension of an image sensing area of the image sensor,wherein a ratio of a total track length of the hybrid lens optical imaging system to the maximum image circle diameter of the image sensor is less than 1.3.

27. The method of claim 26, wherein the meta-optical element stack comprises at least two meta-optical element structures disposed on separate substrates.

28. The method of claim 27, further comprising a step of directly bonding the separate substrates together without an air gap between them.

29. The method of claim 26, wherein the refractive lens comprises a planoconvex-shaped lens wherein the curved front surface is a convex surface.

30. The method of claim 26, wherein the refractive lens comprises a meniscus-shaped lens, wherein the curved front surface is convex, and wherein the planar rear surface surrounds a concave rear surface of the refractive lens.

31. The method of claims 26-30, further comprising a step of providing an aperture stop between the refractive lens and the meta-optical element stack.

32. The method of claim 31, comprising providing an outer light absorbing layer on outer sides of the meta-optical element stack, wherein image sensor is configured to sense light having one or more wavelengths, and wherein the outer light absorbing layer is configured to absorb light having the one or more wavelengths.38

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