Image sensor and method of operating thereof

Abstract

Optical spectrometers can be used to determine the spectral components of electromagnetic waves. Spectrometers can be large and bulky devices, and may require waves entering at a nearly direct angle of incidence to record measurements. Disclosed is a micro-spectrometer featuring nanophotonic components as an optical dispersion technique. The nanophotonic components may include metasurfaces and Bragg filters. Each metasurface may contain light-scattering nanostructures that can be randomized to generate large input angles, and the Bragg filter may cause optical dispersion independently of the input angle. The spectrometer can handle a bandwidth of approximately 200 nm. The micro-spectrometer can read image data of visible light (400–600 nm) and spectral data of near-infrared light (700–900 nm). With a surface area of ​​approximately 1 mm², the spectrometer may be suitable for mobile devices.

Description

Technology Field

[0001] The invention disclosed herein relates to a spectrometer. For example, aspects of some exemplary embodiments relate to a metasurface configuration and manufacturing method, spectroscopy and imaging, and spectrometer components. Background Technology

[0002] Optical spectroscopy is a key characterization technique in diverse environments, ranging from scientific research to industrial and medical applications. Spectrometers can generate spectral lines and measure their wavelengths and intensities. Spectrometers utilize dispersion elements, such as diffraction gratings or prisms, to achieve wavelength-dependent angle dispersion associated with focusing optics that concentrate incoming light to a detector. Because these spectrometers are bulky and have low angular tolerance (angle tolerance is the angle at which incident light strikes the spectrometer for spectroscopy to be performed), their use in mobile devices is limited; therefore, there is a demand for compact spectrometers with high angular tolerance.

[0003] The information disclosed in this section is intended solely to enhance understanding of the background of the disclosed technology and may include information that does not constitute prior art. The problem to be solved

[0004] The objective of the present invention is to provide a compact spectrometer with a high angular tolerance that can be used in portable devices such as smartphones. means of solving the problem

[0005] According to one embodiment, an image sensor may be provided comprising an aperture, a dispersion array, a lens, an image sensor, and a processor.

[0006] According to another embodiment, a method for obtaining spectral data from a sensor may be provided, comprising: receiving incident light; scattering the incident light through a scattering layer to generate scattered light; dispersing a subset of the scattered light through a dispersion layer to generate dispersed light; receiving the dispersed light at an image sensor; and reconstructing spectral data from the dispersed light.

[0007] According to another embodiment, a dispersion array may be provided that includes at least one dispersion structure for dispersing light in a target wavelength range starting with 0° (degree) dispersion of the target wavelength, wherein the dispersion structure further includes a nanostructure layer and a filter layer.

[0008] According to another embodiment, a method for manufacturing a dispersion array may be provided, comprising depositing a first filter stack on a substrate; depositing a defect layer; depositing a capping stack; and forming a nanostructure on the capping stack. Effects of the invention

[0009] The image sensor according to the present invention may include a high-performance micro-spectrometer that can be integrated into a portable device such as a smartphone. The spectrometer may have a high tolerance angle to increase the throughput of the device and allow for greater misalignment between the spectrometer and the spectral target, thereby potentially having a larger field of view. Brief explanation of the drawing

[0010] In the following sections, aspects of the invention disclosed herein will be described with reference to the embodiments illustrated in the drawings. Figure 1 illustrates the operating principle of a spectrometer sensor. Figure 2 illustrates the configuration of an example of a compact spectrometer. FIG. 3 illustrates a plan view of a light-dispersion array according to some embodiments of the invention. FIG. 4 illustrates a side view of a dispersion structure according to some embodiments of the invention. FIG. 5 illustrates a manufacturing diagram of a layer and nanostructure formation according to some embodiments of the invention. FIG. 6 illustrates a plan view of a dispersion structure according to some embodiments of the invention. FIG. 7 is a graph showing the density of nanostructures and their metasurface light dispersion efficiency according to some embodiments of the invention. FIG. 8 illustrates a metasurface having a nanoantenna according to some embodiments of the invention. FIG. 9 is a graph showing the dispersion efficiency at various wavelengths after processing raw data into reconstructed images and spectral components according to some embodiments of the invention. FIG. 10 is a graph showing the angular response to scattering at a selected wavelength in an exemplary dispersion structure according to some embodiments of the invention. FIG. 11 illustrates an image sensor having two detection pixels according to some embodiments of the invention. FIG. 12 illustrates a raw image processed into spectral and visible image data according to some embodiments of the invention. FIG. 13 illustrates a manufacturing process of a dispersion structure according to some embodiments of the invention. Specific details for implementing the invention

[0011] The following detailed description and numerous specific details are described to provide a complete understanding of the invention. However, it will be understood by those skilled in the art that the disclosed embodiments may be practiced without these specific details. In other examples, well-known methods, procedures, components, and circuits have not been described in detail to avoid obscuring the subject matter disclosed herein.

[0012] Throughout this specification, the term “one embodiment” implies that a specific function, structure, or characteristic described in relation to an embodiment may be included in at least one embodiment disclosed herein. Accordingly, the appearance of phrases such as “in one embodiment,” “in one embodiment,” or “according to one embodiment” (or other phrases having a similar meaning) in various places throughout this specification does not necessarily refer to the same embodiment. Furthermore, a specific function, structure, or characteristic may be combined in any appropriate manner in one or more embodiments. Additionally, depending on the context of the description in this specification, singular terms may include corresponding plural forms, and plural terms may include corresponding singular forms. Likewise, hyphenated terms (e.g., “2-dimensional,” “pre-determined,” “of a specific pixel,” etc.) may sometimes be used interchangeably with their corresponding unhyphenated versions (e.g., “2-dimensional,” “pre-determined,” “of a specific pixel,” etc.). Additionally, uppercase items (e.g., “Counter Clock”, “Row Select”, “PIXOUT”, etc.) may be used interchangeably with their corresponding non-uppercase versions (e.g., “counter clock”, “row select”, “pixout”, etc.). Such interchangeable use should not be considered inconsistent.

[0013] It should be noted that the various drawings (including component diagrams) shown and discussed in this specification are for illustrative purposes only and are not drawn in proportion. Likewise, the various waveform and timing diagrams are for illustrative purposes only. For example, the dimensions of some elements may be exaggerated relative to others for clarity. Additionally, where deemed appropriate, reference numbers are repeated between drawings to indicate corresponding and / or similar elements.

[0014] The terms used herein are merely for describing some exemplary embodiments and are not intended to limit the subject matter of the claims. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless otherwise clearly indicated by the context. It will be further understood that the terms “comprising” and / or “comprising” used herein specify the presence of the mentioned features, integers, steps, operations, elements, and / or components, and do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Terms used herein such as “first,” “second,” etc. are used merely as labels for the preceding nouns and do not imply any type of order (e.g., spatial, temporal, logical, etc.) unless explicitly defined otherwise. Additionally, the same reference number may be used across two or more drawings to refer to parts, components, blocks, circuits, units, or modules having the same or similar functions. However, such usage is for the sake of simplicity of description and ease of discussion; It does not mean that the structure or structural details of such components or units are the same across all embodiments, or that a generally referenced part / module is the only way to implement some of the exemplary embodiments disclosed herein.

[0015] When one element or layer is referred to as existing on, or “connected” or “combined” to another element or layer, it may be understood as existing directly on, being directly connected to, or being directly combined to the other element or layer, or as having another element or layer interposed therein. In contrast, when one element is referred to as being “directly connected,” “directly connected,” or “directly combined” to another element or layer, it may be understood that no intermediate element or layer exists. The same reference number denotes the same element throughout. As used herein, the term “and / or” includes all combinations of one or more associated enumerated items.

[0016] Unless otherwise defined, all terms used herein (including technical or scientific terms) have the same meaning as generally understood by a person skilled in the art of this invention. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with that meaning in the context of the relevant technology and should not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0017] An exemplary optical spectrometer (100) is illustrated in FIG. 1. A light source (101) may be provided. The light source (101) may include a visible light spectrum and an invisible light spectrum, but may also have a spectrum from long infrared (or below) to gamma rays. The light source (101) may be used to form any of the mentioned wavelengths. The light source (101) may be derived from a hot solid that emits light (which may or may not be absorbed by the material between them, creating absorption lines), or from an emission spectrum where the intensity and location of the spectral lines depend on the characteristics of the emitting material and the source of emission. The input to the light source (101) may be spatial light or from an optical fiber. Light from the light source (101) passes through an entrance slit (102) at an incident light arrival angle (108). The angle of incidence light arrival (108) can generally be 0° to 2° depending on the opening of the entrance slit (102).

[0018] The entrance slit (102) may have an opening of a square, rectangular, or other shape. The optical resolution and throughput of the spectrometer may be determined by the entrance slit (102). Light entering the spectrometer may be focused at the entrance slit (102), and the entrance slit (102) may be aligned with the optical spectrometer (100) so that the light can pass through other components. The width of the slit is generally 5 μm to 800 μm and the height is 1 mm to 2 mm, but may have other sizes.

[0019] When a light source (101) is incident on an entrance slit (102), it can be reflected by a collimating mirror (103) having a focal length (107) which may be the distance between the entrance slit (102) and the collimating mirror (103). The collimating mirror (103) may be a concave mirror. The collimating mirror (103) can collect light from the light source (101) and direct the waves parallel to a diffraction grating (104).

[0020] A diffraction grating (104) can separate light directed by a collimating mirror (103) into different wavelengths, and the different wavelengths can be diffracted at a specific angle for each wavelength. These different wavelengths can pass through the diffraction grating (104) or be reflected at different diffraction angles. Different transmission gratings may be used for different wavelength ranges. The diffraction grating (104) may be a holographic grating or a ruled grating. A holographic grating can be developed by interfering two ultraviolet rays on a piece of optical glass, in which case a sinusoidal index of refractive index fluctuations may be generated. A ruled grating can be developed by etching grooves parallel to the surface of a substrate and coating the parallel grooves with a reflective material. A ruled grating may generate more stray light due to surface defects. The number of grooves per unit length of the ruled grating and the width of the grooves may affect the amount of scattered light. The number of grooves per unit length of the ruled grating is known as the groove frequency or groove density. The wavelength range of a spectrometer having a diffraction grating (104) can be inversely proportional to the groove density.

[0021] Light from a light source (101) can be dispersed and reflected from a diffraction grating (104) and then reach a focusing mirror (105). The focusing mirror (105) can be concave and can focus the light rays onto an image sensor (106). The image sensor (106) can include pixels. The focusing mirror (105) can form an image of light dispersed into selected wavelengths. The focusing mirror (105) can reflect the dispersed light into rays of various wavelengths. Each ray of various wavelengths can be at a different angle from the diffraction grating (104) and the focusing mirror (105). These rays can reach the pixels of the image sensor (106), and each pixel can receive a different wavelength based on the angle of dispersion of the rays. The image sensor used may vary depending on the measured wavelength and may include short-wave infrared (SWIR), near-infrared (NIR), visible light, ultraviolet (UV), X-rays, etc. These sensors may be CCD (charge coupled device), CMOS (complementary metal-oxide-semiconductor), NMOS (n-type metal-oxide-semiconductor), InGaAS, a Si photodiode array with an amplifier, PMT (photomultiplier), APD (avalanche photodiode), or other sensors.

[0022] The diffusion of light from the diffraction grating (104), which can be reflected from the focusing mirror (105), reaches the image sensor (106). The light interacts with the pixels of the image sensor (106) to generate voltage. The size of the image sensor (106) can affect the field of view. The resolution of the image sensor (106) can be determined by pixel density, pixel size, and the focal length of the focusing mirror (105), which may be the distance between the focusing mirror (105) and the image sensor (106). The focal ratio (the value obtained by dividing the focal length by the diameter of the focusing mirror (105)), the pixel size of the sensor, and the quantum efficiency (which can be measured as a conversion between the number of electrons in an image and the number of digitals) can determine the sensitivity of the image sensor (106). Although not illustrated, a processor can analyze the voltage generated in a set of pixels to interpret the spatio-spectral distribution.

[0023] A shift in resonance may occur because the wavelengths can be blurred together in the diffraction grating (104). When read by the pixels of the image sensor (106), blur may occur if two wavelengths are diffracted and overlap each other. The blur may be caused by the resolving power of the diffraction grating (104). Wavelengths may overlap if the gratings of the diffraction grating (104) are too thin, too close together, or if the light enters at an angle. When wavelengths overlap, the ability to read the wavelengths is degraded. A shift in resonance may lead to signal failure, and the angular tolerance may be less than 2°. The spectrometer of FIG. 1 can only provide spectroscopy. Due to design and space constraints, it cannot provide spectroscopy while simultaneously imaging a target (which may require a separate set of optics and detectors for a specific purpose).

[0024] The spectrometer of Fig. 1 can be used by technical experts for highly specialized applications, but it cannot be used in consumer devices due to the size and cost of the components. It may be useful to implement a high-performance, ultra-compact spectrometer that can be integrated into portable devices such as smartphones. In addition to performance parameters of the spectrometer such as high resolution, high throughput, and a wide spectral range, it may be useful for the portable spectrometer to have a large input angle tolerance. A high angle tolerance can increase the device's throughput, allow for greater misalignment between the spectrometer and the spectroscopic target, and potentially provide a larger field of view. This can be useful for portable applications where an untrained user can hold the spectrometer in their hand and obtain good measurements without achieving the same precise alignment as would be achieved in a fixed laboratory setting.

[0025] FIG. 2 illustrates a sensor (200) (e.g., a spectrometer, a spectrometer and imaging device, etc.) according to some embodiments of the present invention. The sensor (200) may be a micro-spectrometer sensor. The sensor (200) may also be a micro-spectrometer, combined imaging and spectrometer sensor. Incident light (201) may enter an aperture (202), and the aperture (202) may be used to focus light onto a dispersion array (204). In one embodiment, the aperture (202) may limit the field of view to + / - 15°; however, in some embodiments, the field of view may be larger or smaller. The aperture (202) may be a triplet lens for providing near-field spectroscopy, but may be other types of lenses. For example, the aperture (202) may be a slit similar to the entrance slit (102) and may have a wider field of view, such as + / - 30°. In one embodiment, the surface area of ​​the dispersion array (204) may be approximately 1 square millimeter, but may be smaller or larger than this. The dispersion array (204) may include nanophotonic components.

[0026] As used herein, “scattering” may be defined as a deviation of a ray from its initial trajectory. “Dispersion” may be defined as light that can be separated into constituent wavelengths. Dispersed light may be scattered light.

[0027] The dispersion array (204) can scatter incident light (201) in first and second wavelength ranges, and a detailed description thereof will be given later. The dispersion array (204) can allow light to pass through with little or no dispersion in the first wavelength range, and can disperse light in the second wavelength range. The dispersion array (204) can be integrated with the aperture (202) so that the aperture (202) is manufactured using the same process as the dispersion array (204).

[0028] Incident light (201) passing through the aperture (202) and the dispersion array (204) can pass through a lens (205). The lens (205) can focus the light onto an image sensor (206). In one embodiment, the lens (205) may be an optical lens, a metalens, or another lens. In an alternative embodiment, the aperture (202) may be integrated with the dispersion array (204) and the lens (205). In another alternative embodiment, the aperture (202), the dispersion array (204), the lens (205), and the image sensor (206) may all be integrated. In one embodiment, the image sensor (206) may be used to read only spectral data. In another embodiment, the image sensor (206) may be used to read both image and spectral data. The image sensor (206) may have an inner region (208) and an outer region (209). The image sensor (206) can simultaneously read spectral data of a second wavelength range through the outer region (209) and image data of a first wavelength range through the inner region (208), and a detailed description thereof will be provided later. Reading both image and spectral data can enable the sensor (200) to distinguish between a “real” object and a “false” object. For example, if the object to be analyzed is a physical object and a photograph of the object is presented to the sensor (200), the photograph of the object may appear to be the same image as the original object, but the spectral data of the captured object may differ. Spectral data can be used to detect these differences between the “real” image and the “false” image.

[0029] The image sensor (206) may be a CMOS sensor or any previously described sensor, or any other sensor capable of detecting wavelengths designed for combined imaging and spectroscopic sensors (200). The image sensor (206) may be connected to an image processor (207) capable of processing image and / or spectral data. The image processor (207) may reconstruct visual and / or spectral data.

[0030] The sensor (200) may be small enough for use in a smartphone camera and may provide hybrid imaging and spectroscopy capabilities. The size of the sensor (200) may be 0.1 to 3 cubic millimeters or less, which allows it to fit within a small form factor device. The dispersion array (204) may have a volume of about 0.01 cubic millimeters. For example, in some embodiments, the dispersion array (204) may be placed on top of or between layers of camera lenses to enable the smartphone camera to use the sensor (200). The smartphone camera may include a lens (205), an aperture (202), an image sensor (206), and an image processor (207). Depending on the design, the dispersion array (204) may be placed before or after the smartphone lens or aperture. In other embodiments, the sensor (200) may be integrated into the smartphone camera.

[0031] FIG. 3 illustrates a dispersion array (204). The dispersion array (204) may include an array of dispersion structures (300a-300n). A first dispersion structure (300a) may allow light of a first wavelength range to pass through with reduced dispersion or no dispersion, reduced scattering or no scattering, and may cause light of a second wavelength range to scatter and disperse. In one embodiment, the dispersion structures (300a-300n) may each be approximately 500 μm x 500 μm squares, but may have other sizes and shapes. The dispersion structures (300a-300n) may disperse light of different wavelength ranges. For example, the first dispersion structure (300a) disperses light in the wavelength range of 800 nm to 820 nm, while the second dispersion structure (300b) disperses light in the wavelength range of 820 nm to 840 nm, and the same applies to the remaining dispersion structures (300a-300n).

[0032] Each dispersion structure (300a-300n) can disperse light for a different subset of the wavelength range or bandwidth that the entire dispersion array (204) disperses. For example, the dispersion wavelength range for the dispersion array (204) may be 800 nm to 1000 nm, and if there are 8 dispersion structures (300a-300n, n=8), each dispersion structure (300a-300n) may disperse a bandwidth of about 25 nm within the range of 800 nm to 1000 nm. In an alternative embodiment, there may be multiple dispersion structures (300a-300n) for a given subset of the wavelength range to provide redundancy. For example, the dispersion array (204) may include 16 dispersion structures (300a-300n), the wavelength range is 800-1000 nm, and the dispersion array (204) may be designed so that each dispersion structure (300a-300n) disperses a bandwidth equivalent to about 25 nm in the range of 800-1000 nm, but there may be two dispersion structures (300a-300n) that share a dispersion bandwidth.

[0033] The dispersion structures (300a-300n) can disperse light along a single axis. For example, incident light (201) can be dispersed along an axis perpendicular to the rows of nanostructures (403a-403n) found in the dispersion structures (300a-300n), which will be further introduced and discussed below. The dispersion structures (300a-300n) can be positioned to provide light scattering and light dispersion at different angles relative to one another. In other words, each dispersion structure (300a-300n) is dispersed along an axis, and the dispersion axis from one dispersion structure (300a-300n) to another dispersion structure (300a-300n) is offset by an angle. This principle is illustrated in FIG. 3, and each dispersion structure (300a-300n) has nanostructure rows (403a-403n) formed obliquely with respect to other dispersion structures (300a-300n). For example, the first dispersion structure (300a) may have a corresponding first dispersion structure angle (301a), which may be the axis by which the first dispersion structure (300a) disperses light. The nth dispersion structure (300n) may have a corresponding nth dispersion structure angle (301n), etc. Thus, each dispersion structure (300a-300n) may have a corresponding dispersion structure angle (301a-301n).

[0034] In one embodiment, the angle at which light is dispersed between dispersion structures (300a-300n) may be selected to provide the greatest difference in dispersion structure angles (301a-301n) from one dispersion structure (300a-300n) to another dispersion structure (300a-300n). For example, among n dispersion structures (300a-300n), the difference in dispersion axis angles between individual dispersion structures (300a-300n) may be n / 180°. For example, when n is 8 for dispersion structures (300a-300n), each of the dispersion structures (300a-300n) may rotate approximately 22.5° from 0° to 180° to provide the greatest difference in angle from each other. In alternative embodiments, two or more dispersion structures (300a-300n) may share dispersion structure angles (301a-301n) for redundancy. In alternative embodiments, the dispersion structures (300a-300n) may disperse light along two axes or in a conical shape.

[0035] FIG. 4 illustrates a cross-sectional view of an exemplary dispersion array (204) of FIG. 3 according to some embodiments. In FIG. 4, three dispersion structures are shown for exemplary purposes: 300a, 300b, and 300n. The principles discussed may apply to the first dispersion structure (300a) and may be used for the dispersion array (204) and the dispersion structures (300a-300n) of FIG. 3. Incident light (201) may enter the first dispersion structure (300a) within an angular range (401). In some embodiments, the angular range (401) may be from 0° to + / - 30°, but may be a different range. The structure of the first dispersion structure (300a) and the interaction between the incident light (201) and the first dispersion structure (300a) are further described below.

[0036] The first dispersion structure (300a) may include a multilayer system comprising a nanostructure layer (402) capable of scattering incident light (201) into scattered light (408) and a filter layer (404) capable of dispersing light into dispersed light (410). In one embodiment, each dispersion structure (300a-300n) may scatter and disperse incident light (201) in a similar manner at dispersion structure angles (301a-301n). The nanostructure layer (402) may be known as a scattering layer that can be used to scatter incident light (201). The filter layer (404) may be known as a dispersion layer that can be used to disperse light. The dispersed light (410) may include light of different wavelengths at different angles. For example, the first wavelength may be dispersed at 0° and may be known as the target wavelength (409), while the second wavelength may be dispersed at 10°. There may be a dispersed light (410) that may include a wavelength range and may be based on the optical properties of the filter layer (404). The near-field response (411) may be the response to scattering and dispersion of the incident light (201) for the first few wavelengths of the dispersed light (410) within the first dispersion structure (300a) and after the light leaves the first dispersion structure (300a). The far-field response (415) may be the scattering and dispersion response of the incident light (201) after the near-field response (411). Both are discussed in more detail below.

[0037] The dispersed light (410) may include light of various wavelengths at different angles. More specifically, the dispersion angle at which the dispersed light (410) leaves the first dispersion structure (300a) depends on its wavelength, as illustrated below. The nanostructure layer (402) may include nanostructure rows (403a-403n) (extended along the Z-axis and labeled 403a, 403n-1, and 403n) of nanostructures (illustrated later) capable of scattering light. Incident light (201) may enter the nanostructure layer (402) and interact with the nanostructure rows (403a-403n). A portion of the incident light (201) may be scattered around the nanostructure rows (403a-403n) to create a wavefront. This wavefront may be a scattering of an electric field and may define the propagation of a light field. This can have voltage-meter units and can be considered as a force. The wavefront may follow the Huygens-Fresnel principle, and every point on the wavefront can act as a source of spherical second-order wavelets. The sum of the second-order wavelets can determine the shape of subsequent waves that can generate a far-field response (415). The wavefronts may have waves of various phases and amplitudes and can be added together to generate a far-field response (415). After the incident light (201) interacts with and is scattered by the nanostructure layer (402), the resulting light may interact with the filter layer (404) described below.

[0038] The filter layer (404) may include alternating materials of the first layer (405) and the second layer (406), which will be discussed later with reference to FIG. 5. The defect layer (407) may allow light of a wavelength range to be dispersed. For each dispersion structure (300a-300n), the defect layer (407) may have varying thickness across the dispersion array (204), from one dispersion structure (300a-300n) to another dispersion structure (300a-300n) (e.g., refer to FIG. 4, the defect layer (407) may have different thicknesses between each dispersion structure (300a, b, and n)). The varying thicknesses of the defect layer (407) for each dispersion structure (300a-300n) may allow different wavelength ranges to be filtered and dispersed at different angles. In some embodiments, the defect layer (407) may have different thicknesses for each dispersion structure (300a-300n). In other embodiments, the defect layer (407) may have the same thickness for two or more dispersion structures (300a-300n) to provide redundancy.

[0039] The scattered light (408) may include first and second sets of wavelengths. The scattered light (408) of the first set of wavelengths may pass through the filter layer (404) with little or no dispersion over the first angle range (412) and may be known as specular light. The light of the second set of wavelengths may be scattered and dispersed over the second angle range (413) as dispersed light (410). The second angle range (413) may reach the image sensor (206), or a subset of the second angle range (413) may reach the image sensor (206).

[0040] In one embodiment, the second angle range (413) may be used to read spectral data. For example, from 0° to the end of the image sensor (206), wavelengths that are scattered and dispersed within the second angle range (413) and reach the image sensor (206) may be read spectrally.

[0041] In another embodiment, as described below, the spectrum reading angle range (414) may be a non-overlapping difference between the second angle range (413) and the first angle range (412). The spectrum reading angle range (414) may reach the image sensor (206) or extend beyond the image sensor (206). The spectrum reading angle range (414) may be an angle range in which the diffuse light (410) can be spectrally read by the image sensor (206) and may be known as non-specular light.

[0042] In a specific embodiment, incident light (201) may enter the nanostructure layer (402) between 0° and + / - 30°. Output dispersion may be 0° to + / - 15° for the visible spectrum and 0° to + / - 30° for the NIR spectrum over the range of the input angle of the incident light (201) from 0° to + / - 30°; however, in other embodiments, other angles and wavelengths (from radio wavelengths to gamma wavelengths) are possible. In a spectrum-only reading configuration, the image sensor (206) may be used to read spectrum data from 0° to + / - 30°. In an imaging and spectrum reading configuration, the image sensor (206) may use 0° to + / - 15° to read image data and 15° to + / - 30° to read spectrum data.

[0043] In one embodiment, the nanostructure layer (402) may allow the first dispersion structure (300a) to provide an angular tolerance of + / - 30°, which means that incident light (201) incident between 0° and + / - 30° will provide the same output scattering and dispersion angles. The output dispersion angle and angular tolerance may be due to the structure of the nanostructure layer (402). A more detailed description of the interaction between the incident light (201) and each layer is provided below. Additionally, the materials and structures will also be described in detail.

[0044] The nanostructure layer (402) may be referred to as an optical metasurface. The metasurface may include one or more planar surfaces of phase-shifting arrays of spatially arranged nanoantennas or arrays of light-scattering nanoholes, which may be referred to as scatterers.

[0045] In some embodiments, the nanostructure layer (402) may comprise dielectric-based metasurface materials. The nanostructure layer (402) may comprise a dielectric or semiconductor having a high refractive index. A high refractive index can scatter light more efficiently. Additionally, a material with low light absorption can transmit more light. Examples of materials used include, but are not limited to, titanium dioxide, silicon nitride, silicon, germanium, hafnium oxide, aluminum oxide, or tellurium. These dielectric materials can resonantly capture light and re-emit light with different phases, polarizations, modalities, and spectra.

[0046] The nanostructure layer (402) can bend light through a phase change at its interface and can be described as a generalized version of Snell's law. When light passes between two media, namely air and the nanostructure layer (402), it can be refracted at the interface. In some embodiments, by changing the metasurface structure of the nanostructure layer (402) as described herein, the phase change of light can vary from 0 to 2-pi. The value of the phase change can be controlled by the dimensions and orientation of the metasurface features. When magnetic resonance and electric resonance are superimposed, the phase change can cover the entire 2-pi range.

[0047] More specifically, in some embodiments, the first dispersion structure (300a) may have incident light (201) incident through the nanostructure layer (402). The incident light (201) may be manipulated by the nanostructure layer (402) through Mie scattering to provide scattering according to wavelength. The resulting scattered light (408) may have a changed phase and amplitude. Next, a more detailed description of the filter layer (404) is provided.

[0048] The filter layer (404) may be a reflector. The filter layer (404) may be located on one side of the nanostructure layer (402). The filter layer (404) may reflect some wavelengths while selectively allowing other wavelengths to pass along a narrower wavelength range. The filter layer (404) may disperse a target wavelength range of scattered light (408) as dispersed light (410). The dispersed light (410) may include wavelengths dispersed at different angles (depending on the wavelength) and may include a target wavelength (409). The target wavelength (409) may be a wavelength dispersed at 0° by a specific filter layer (404). The range of the target wavelength may be based on the target wavelength (409) and may include a wavelength range of scattered light (408) dispersed by the filter layer (404). The output angle range according to the dispersion of the target wavelength range may be a second angle range (413).

[0049] The filter layer (404) can obliquely disperse the wavelengths of scattered light (408) in a wavelength-dependent manner to form dispersed light (410). For example, in an exemplary embodiment of the first dispersion structure (300a), the target wavelength (409) may be 835 nm, and the target wavelength range of the dispersed light (410) may be 800-835 nm. The target wavelength (409) of 835 nm may be dispersed at 0°. The wavelength of 820 nm may be dispersed at + / - 15°, and the wavelength of 800 nm may be dispersed at + / - 30°. The filter layer (404) may include a defect layer (407), which can determine the target wavelength range of the dispersed light (410) and its specific wavelength may be dispersed at a specifically fixed angle. The thickness of the defect layer (407) may vary for each dispersion structure (300a-300n) so that the dispersion array (204) can disperse a wide range of wavelengths, as will be discussed further below.

[0050] The filter layer (404) may be a distributed Bragg reflector (DBR), a dielectric mirror, a fiber Bragg grating, a semiconductor Bragg mirror, or other types of devices. The filter layer (404) may be a type of reflector formed of multiple layers of alternating materials having various refractive indices. In one embodiment, the filter layer (404) may be a DBR filter having multiple layers.

[0051] In one embodiment, the filter layer (404) may include one or more alternating layers of the first layer (405) and the second layer (406), but there may be more types of layers and the same principle may apply below. The first and second layers (405, 406) may alternate on top of each other multiple times, maintaining a constant thickness or varying thickness. The defect layer (407) may be a constant layer or a variable thickness layer comprising the material of the first layer (405) or the second layer (406) (in this example, the defect layer (407) is shown having the material of the first layer (405)). In some embodiments, the defect layer (407) may be composed of an alternative material.

[0052] The first and second layers (405, 406) may have boundaries that can cause partial reflection of optical waves and may block specific wavelengths by providing interference to the incident light (201). The first and second layers (405, 406) may have different refractive indices that allow specific wavelengths to pass through and change phase, which may lead to wavelength-dependent angular dispersion. The refractive index of the material may vary depending on the wavelength of light entering the material; therefore, the provided refractive index value may be an average value over a wavelength range. In one embodiment, the first layer (405) may be TiO2. The refractive index of TiO2 is about 2.45 and may be considered a high refractive index. In one embodiment, the second layer (406) may be SiO2. The refractive index of SiO2 is about 1.45 and may be considered a low refractive index. The two refractive index values ​​may be higher or lower. Both values ​​may depend on a specific wavelength of light passing through, and it may be helpful to consider the refractive index averaged over the wavelength range of interest. The same principle described above may be applied to additional layers including the defect layer (407) and layers of other materials.

[0053] The first and second layers (405, 406) may have different thicknesses, which may also determine which wavelengths can pass through the material. The reflectance of the first and second layers (405, 406) may all depend on the configuration of the destructive interference region of light reflected at the boundary of each layer.

[0054] For each layer of the material, light may have a phase delay within the material of the first refractive index n. Light may follow the rule c = λf, where c is the speed of light, λ is the wavelength, and f is the frequency. When light passes through the material of the first refractive index n, the speed of light may vary by multiplying by 1 / n. Since the frequency f is fixed, the wavelength λ may also vary by multiplying by 1 / n, known as the effective wavelength. The effective wavelength of light may vary within the material. Furthermore, the thickness d of the material may allow light of the first wavelength to pass through while other wavelengths may be reflected. Other wavelengths may be reflected from the outer and inner surfaces. Light reflected from the inner surface of the material may have a phase delay that can interact with light reflected from the outer surface to produce interference, and said interference may be constructive or destructive interference. Therefore, the refractive index, along with the thickness of the material, may allow a selected wavelength to pass through the material. When the first layer (405) is stacked on the second layer (406), the reflection of the two layers can filter many wavelengths while allowing a narrow wavelength range to pass through using the principles described herein. The first layer (405) and the second layer (406) together may be referred to as a stack. The layers are described in more detail below. The principles below may also be applied to additional layers of the stack, such as the defect layer (407) or layers above.

[0055] In some embodiments, the first and second layers (405, 406) may each be a single individual material and each may be a dielectric material. The first layer (405) may have a high refractive index, while the second layer (406) may have a low refractive index, or both may have a high refractive index. The first layer (405) and the second layer (406) may be repeatedly stacked on top of each other, which can generate Fresnel reflection at the interfaces of the alternating layers. The first layer (405) may have a refractive index n1, and the second layer (406) may have a refractive index n2. Together, the Fresnel reflection is [(n1-n2) / (n1+n2)] 2 It could be.

[0056] The effective thickness of the material may be the refractive index multiplied by the thickness of the material, which can be used to determine the dispersion characteristics of the material. This concept can be applied to the first layer (405) and the second layer (406). When the first layer (405) and the second layer (406) are combined into a stack, the effective thickness can be used to adjust the filter layer (404) to disperse the target wavelength range. Adding subsequent stacks on top of each other can improve dispersion efficiency, but the target wavelength range may not change because the effective thickness of each stack may be the same. By adding a defect layer (407), the target wavelength range can be adjusted as the effective thickness changes when the defect layer (407) is added to the stack. As will be discussed later, the dispersion array (204) may have the same stacks for each dispersion structure (300a-300n), but may have a defect layer (407) of varying thickness that allows different target wavelength ranges for each dispersion structure (300a-300n).

[0057] When combined to form a stack, the effective thickness of the first layer (405) and the second layer (406) may have a thickness multiplied by a refractive index approximately equal to about 1 / 2 or 1 / 4 of the target wavelength (409), where the target wavelength (409) may be dispersed at 0°. For example, for thicknesses d1 and d2 of the first layer (405) and the second layer (406), respectively, the effective thickness may be n1*d1 + n2*d2 and may be adjusted to be equal to about 1 / 2 or 1 / 4 of the target wavelength (409). To increase the dispersion efficiency, additional stacks of the same thickness may be added, but the same target wavelength (409) may be dispersed at 0°. In other cases, if a defect layer (407) with a refractive index of n1 and a thickness of d3 is included, the formula may be n1*d1 + n2*d2 + n1*d3, which may be approximately 1 / 2 or 1 / 4 of the target wavelength (409). The stack and the defect layer (407) may be used to determine the target wavelength range. As previously mentioned, the target wavelength range of the filter layer (404) may be the wavelength range in which dispersion may occur in each dispersion structure (300a-300n) and is based on the target wavelength (409) for a specific dispersion structure.

[0058] In an alternative embodiment, each dispersion structure (300a-300n) may use different materials and / or thicknesses of stacks of first and second layers (405, 406) to target a wavelength range using the principles above. The stack may include two or more layers, and each layer may have different materials and thicknesses. In an embodiment having multiple stacks, each stack may also include different materials and thicknesses, or the same material and thickness.

[0059] Half of the effective thickness of the target wavelength (409) can cause constructive interference and function as a highly reflective material. One-quarter of the effective thickness of the target wavelength (409) can cause destructive interference and function as a low-reflective material. By stacking multiple alternating first and second layers (405, 406), a more effective phase shift can occur, which can allow for a more efficient filter. In one example, by stacking four layers of the first layer (405) and the second layer (406), the resolution of the wavelength dispersion can be 2 nm to 5 nm. As more stacks are added, the resolution may decrease (a higher value such as 5 nm to 10 nm). As fewer stacks are added, the resolution may increase (a lower value such as 1 nm to 2 nm).

[0060] In one embodiment, by stacking the first layer (405) and the second layer (406), the period of the light wave of the incident light (201) can be shifted by pi, which can cause destructive interference and thereby allow other wavelengths to pass through the filter, while blocking or filtering the selected wavelength. Each layer of the filter layer (404) may have a boundary, which can cause partial reflection of the light wave. When multiple layers are added together to form a stack, many reflections may be combined with constructive (half-wavelength) or destructive (quarter-wavelength) interference and may reflect or block the selected wavelength passing through the filter layer (404).

[0061] For a simple example of destructive interference where the defect layer (407) is absent, if the target wavelength (409) is 800 nm, the first and second layers (405, 406) may have a combined effective thickness of two quarter-wavelength filters, which may shift the wavelength by 200 nm each or a total of 400 nm. By shifting the 800 nm wavelength by 200 nm twice (i.e., a total of 400 nm shift), destructive interference may occur and the target wavelength (409) may be blocked. However, in constructive interference, the target wavelength (409) may be allowed to pass through.

[0062] In other embodiments, the effective thickness of a stack including a first layer (405) and a second layer (406) may be less than 1 / 2 or 1 / 4 of the thickness of the target wavelength (409), but may be added to 1 / 2 or 1 / 4 of the thickness of the target wavelength (409) when multiple stacks are added together. In other embodiments, as described herein, additional variables including refractive index, thickness, additional layers, etc. may be used to determine the effective thickness of the first and second layers (405, 406).

[0063] As discussed below, the defect layer (407) can also change the target wavelength (409) that can be filtered. By changing the effective thickness of the defect layer (407), the dispersion structure (300a-300n) can be adjusted, and accordingly, various target wavelengths (409) of scattered light (408) can be dispersed as part of the dispersed light (410) at about 0°.

[0064] The defect layer (407) can be adjusted so that the target wavelength range is dispersed. The defect layer (407) may include steps having different thicknesses for each dispersion structure (300a-300n), which are shown with varying thicknesses along the X-axis of FIG. 4. A first step thickness may cause the first target wavelength range to be dispersed on the first dispersion structure (300a), and an nth step thickness may cause the nth target wavelength range to be dispersed on the nth dispersion structure (300n). For example, for each thickness step of the defect layer (407) on the dispersion structure (300a-300n), the target wavelength range may be 20 nm to 40 nm, but other wavelength ranges may be possible and may depend on the material of the defect layer (407) (e.g., refractive index) and the selection of the step size.

[0065] Over the entire range of dispersion structures (300a-300n) on the dispersion array (204), the thicknesses of the defect layer (407), the first layer (405), and the second layer (406) can select the entire range of wavelengths that can be dispersed. For example, the target wavelength range may be 700 nm to 725 nm for the first dispersion structure (300a), 725 nm to 750 nm for the second dispersion structure (300b), and likewise 875 nm to 900 nm for the nth dispersion structure (300n). The entire range of wavelengths that can be dispersed in the dispersion array (204) may be 700 nm to 900 nm. Each dispersion structure (300a-300n) may disperse more wavelengths than their respective target wavelength ranges, but these wavelengths may be at a wider dispersion angle than where the waves may not reach the image sensor (206). Accordingly, the defect layer (407) can be designed to place a specific portion of the spectrum (target wavelength range) distributed within a specific angle range (which may be a second angle range (413) or a spectrum reading angle range (414)) on the image sensor (206), defined by the physical size and placement of the image sensor (206).

[0066] More specifically, referring to FIG. 3, each dispersion structure (300a-300n) may have a defect layer (407) with a thickness different from the other dispersion structures (300a-300n) to allow dispersion of a wide range of wavelengths over the entire dispersion array (204). More specifically, if the thickness of the step of the defect layer (407) as described above is x and the base height of the layer required for the target wavelength (409) is n (as described above), the first dispersion structure (300a) may have a thickness of approximately n+x, the second dispersion structure (300b) may have a height of n+2x, and the third dispersion structure (300c) may have a thickness of n+3x, and so on.

[0067] More specifically, in some embodiments, the defect layer (407) may have various thicknesses (one thickness per dispersion structure (300a-300n)) so that various target wavelength ranges of light can pass through. For each dispersion structure (300a-300n), there may be a target wavelength (409), which may be defined as the wavelength at which light is dispersed at 0°. The target wavelength (409) for each dispersion structure (300a-300n) may be different or may be shared by two or more dispersion structures (300a-300n) to provide redundancy.

[0068] As described above, the dispersion structures (300a-300n) may not “stop” wavelength dispersion at the edges of their respective wavelength ranges (e.g., 700-725 nm). Rather, wavelengths dispersed beyond the physical boundaries of the image sensor (206) (e.g., beyond + / - 30° in some embodiments) are not detected and are not considered part of the “wavelength range” for this discussion. That is, the dispersion wavelength range of each dispersion structure (300a-300n) may start at 0° relative to the target wavelength (409) and extend to an angle defined by the outer limit of the image sensor (206).

[0069] For example, for the dispersion array (204) of FIG. 3, there may be dispersion structures (300a-300n) with n=8. Additionally, for example, the dispersion array (204) may disperse wavelengths from 700 nm to 900 nm. According to this example, the dispersion structures of the dispersion structures (300a-300n) may each disperse a target wavelength range of about 25 nm. The first dispersion structure (300a) may disperse from 700 nm to 725 nm (which may be the first target wavelength range). The target wavelength (409) dispersed at about 0° may be 725 nm. The 700 nm wavelength may be dispersed at + / - 30°, and wavelengths in between may be dispersed at lower angles. The defect layer (407) may be the first thickness in the first dispersion structure (300a). The second dispersion structure (300b) can disperse from 725 nm to 750 nm (which may be the second target wavelength range). The target wavelength (409) dispersed at approximately 0° may be 750 nm. The defect layer (407) may have an additional thickness added to the second dispersion structure (300b) (compared to the first dispersion structure (300a)) to disperse a different target wavelength (409) at 0° and may have the second target wavelength range (compared to the first dispersion structure (300a)). For example, when the refractive index of the defect layer (407) is 1.25, the additional thickness may be 20 nm, which allows for a 1.25 * 20 = 25 nm transition in the target wavelength (409) and wavelength range to be dispersed. Of course, if the desired target wavelength (409) transition or the material refractive index is different, a different defect layer (407) thickness may be used.

[0070] In some embodiments, from the dispersion structure (300a-300n), the defect layer (407) has a thickness that is gradually added in the manner described above, allowing dispersion of the entire target wavelength range.

[0071] In some embodiments, the image sensor (206) may read imaging data from a first angle range (412) and read spectral data from the dispersed light (410) of the spectral reading angle range (414). In an exemplary embodiment, the spectral reading angle range (414) may be from + / - 15° to + / - 30°, and the first angle range (412) in which imaging data is read may be from 0° to + / - 15°. To compensate for the fact that some angles of the dispersed light (410) may not be used for spectroscopic data, the overlap of target wavelengths (409) between the dispersed structures (300a-300n) may be engineered according to the principles disclosed herein.

[0072] For example, the first dispersion structure (300a) may have a first target wavelength range that disperses from 700 nm to 735 nm. The target wavelength (409) dispersed at approximately 0° may be 735 nm. The 700 nm wavelength may be dispersed at + / - 30°, and the 725 nm wavelength may be dispersed at + / - 15°. Thus, for example, the first dispersion structure (300a) may provide a spectrum reading in the range of ~700-725 nm, and the ~725-735 nm wavelength may be outside the spectrum reading angle range (414) on the image sensor (206) (yet, within the first angle range (imaging data angle, 412)).

[0073] The second dispersion structure (300b) may have a thicker defect layer (407). The second dispersion structure (300b) may have a second target wavelength range that disperses light from 725 nm to 760 nm. The target wavelength (409) dispersed at approximately 0° may be 760 nm. The 725 nm wavelength may be dispersed at + / - 30°, and the 750 nm wavelength may be dispersed at + / - 15°. Thus, the second dispersion structure (300b) may provide spectral readings in the 725-750 nm range, and the ~750-760 nm wavelength may be outside the spectral reading angle range (414) on the image sensor (206). Thus, the target wavelength range of the second dispersion structure (300b) may compensate for the fact that a portion of the target wavelength range of the first dispersion structure (300a) is not measured. This superposition principle is repeated across dispersion structures (300a-300n) to continuously cover wavelengths from 700 nm to 900 nm.

[0074] Details of the target wavelength range (and related target wavelength (409)) that can be pursued for individual dispersion structures (300a-300n) may be based on various other factors apparent to a person skilled in the art after reading this specification, as well as the entire frequency range of the spectrum analyzed by the image sensor (200), the angles from which image data versus spectrum data can be obtained from the image sensor (206) of FIG. 2 (which may be based on physical design variables of the image sensor (206)), the number of dispersion structures (300a-300n), and any redundancy pursued.

[0075] Referring again to FIG. 4, as will be shown in more detail in FIG. 10, the wavelength intensity of the dispersed light (410) may vary depending on the dispersion angle and may be known as the transmitted angular intensity. The transmitted angular intensity of the wavelength may be a function of the refractive index and thickness of the filter layer (404) material, the composition of the nanostructure layer (402), the scattered light (408), and the number of stacks of (first and second layers (405, 406)). The transmitted angular intensity can be calculated for each wavelength and a distribution of each intensity can be generated. The dispersion of the dispersed light (410) can be calculated from the distribution. The above calculation can be used to design the filter layer (404), including the thickness of the first and second layers (405, 406), the materials, and the number of stacks. Further details are provided below.

[0076] FIG. 5 provides a graphic example of a process (500) for manufacturing a dispersion array (204) according to some embodiments. As discussed in FIG. 4, the first dispersion structure (300a) may include a nanostructure layer (402) and a filter layer (404). FIG. 5 may show a side view of dispersion structures (300a-300n), wherein additional layers of the nanostructure layer (402) or the filter layer (404) may be created or used during the manufacturing process. In an exemplary figure, the defect layer (407) may have eight steps and may show a dispersion array (204) having eight dispersion structures (300a-300n) side by side. The manufacturing of the dispersion array (204) may be monolithic; that is, the design of all dispersion structures (300a-300n) may be performed together.

[0077] A layer of the substrate (501) can be used as a base for adding additional layers to the dispersion structures (300a-300n). The substrate (501) may be glass, silicon, or other optically transparent material in the wavelength range of interest. The substrate (501) may be used in the manufacturing process and discarded after manufacturing. As shown in the structure (510), the first and second layers (405, 406) may be deposited alternately to form the first filter layer (502). In one embodiment, the first and second layers (405, 406) are composed of two different materials; however, there may be additional layers of other materials used. The first layer (405) may have a first thickness (d1), and the second layer (406) may have a second thickness (d2). The alternating first and second layers (405, 406) may have the same thickness (d1 and d2) or may differ. The first filter layer (502) may allow filtering of a selected wavelength to pass through.

[0078] A defect layer (407) may be manufactured on the first filter layer (502). The defect layer (407) may include a stepped step pattern of various thicknesses. The various thicknesses of the defect layer (407) may allow for dispersion of light across various wavelength ranges. The defect layer (407) may be manufactured with a defect preparation layer (504) and one or more defect photolithography layers (503). The defect photolithography layer (503) may be one or more lithography masks and may be a polymer film. The defect preparation layer (504) may be the same material as or different from one of the first and second layers (405, 406). The defect preparation layer (504) may be deposited on the first filter layer (502). The defect photolithography layer (503) may be deposited on the defect preparation layer (504) to form a lithography structure (511). Photolithography masking and etching are applied to the defect photolithography layer (503) (in one or more repeated processes described in more detail below) to change the structure of the defect preparation layer (504) and to form a structure (512) including the defect layer (407) of the final structure of the defect layer (407) (described in more detail below).

[0079] Additional first and second layers (405, 406) may be deposited alternately on the defect layer (407) to form a second filter layer (505). The first filter layer (502), the defect layer (407), and the second filter layer (505) may constitute the filter layer (404) of FIG. 4. Referring again to FIG. 5, a capping stack (506) may be deposited and flattened on the second filter layer (505) to form a structure (513). The capping stack (506) may have a temporarily deposited lithography mask (507), which allows for the lithographic generation of nanostructure rows (403a-403n) by etching to form a structure (514). When the nanostructure columns (403a-403n) are etched in each dispersion structure (300a-300n), the lithography mask (507) can be removed and form a structure (515) that may be the dispersion structures (300a-300n).

[0080] In one embodiment, the first layer (405) may be titanium dioxide (TiO2) and may be deposited using a sputtering method, but may also be deposited using any other technique for depositing material on a substrate (501).

[0081] The second layer (406) may be silicon dioxide (SiO2). The second layer (406) may be deposited via plasma enhanced chemical vapor deposition (PECVD), but may also be deposited via any other technique.

[0082] In one embodiment, to target a wavelength of 800 nm, the first layer (405) comprises TiO2 and the second layer (406) comprises SiO2, the thickness of the first layer (405) may be 83 nm, and the thickness of the second layer (406) may be 135 nm. Prior to the defect layer (407), there may be four stacks of the first and second layers (405, 406) stacked on top of each other for a total of eight layers (four layers of the first layer (405) alternating with four layers of the second layer (406)). There may be fewer or more stacks. After the defect layer (407), there may be another four stacks of the first and second layers (405, 406). To target different wavelengths, different thicknesses may be used as discussed herein. There may be fewer or more stacks.

[0083] As described above, the defect layer (407) may be formed by depositing a thicker layer of the first layer (405) or the second layer (406), which may be the defect preparation layer (504). Greyscale lithography technology may be applied to form the defect layer (407). Ultraviolet (UV) exposure may be applied to the defect photolithography layer (503). The defect photolithography layer (503) may cover the entire surface of the defect preparation layer (504). As shown in the example illustrated in FIG. 5, UV radiation may be applied over a range (508) in the X-axis direction, and the total dose of UV exposure may vary over the range (508). UV radiation may also be applied in the Z-axis direction. Variable capacitance power or variable time capacitance of UV exposure may be applied, which will affect the durability of the defective photolithography layer (503) under etching treatment along the X-axis direction and may cause variation in the thickness of the defective layer (407). For example, the variable capacitance power levels for eight divisions may be power levels of x, 7 / 8x, 6 / 8x, and as low as 1 / 8x. The variable time capacitance of UV exposure may have the same power level x and may have times of t, 7 / 8t, 6 / 8t, and as low as 1 / 8t for each division. After UV exposure is applied, etching may be performed, which may form the defective layer (407). The etching may be dry or wet etching.

[0084] In an exemplary alternative approach, the stepped structure of the defect layer (407) is formed from the defect preparation layer (504) using repeated etchant masking lithography. Specifically, in each round of lithography, an etchant mask covering one step fewer than the previous etchant masking step is used, and the device is etched one “step” lower in height. Repeating this process forms the stepped structure.

[0085] FIG. 6 illustrates a top view of an exemplary first dispersion structure (300a), and in particular, a top view of the nanostructure layer (402) of FIG. 4. Along the X-axis direction, nanostructure columns (403a-403n) are distributed. The nanostructure columns (403a-403n) may include a plurality of nanoholes or nanoantennas (here, illustrated as nanoholes) arranged along the Z-axis direction. The nanostructure columns (403a-403n) may be arranged next to each other along the X-axis direction and may be arranged parallel to each other along the Z-axis direction. The nanostructure columns (403a-403n) may be distributed in a pattern, and the pattern may be a semi-random pattern. The distance between two adjacent nanostructure columns (403a-403n) may be randomly distributed between an allowable minimum distance and a maximum distance for adjacent columns along the X-axis direction. In one embodiment, the nanostructure columns (403a-403n) may have a maximum distance between adjacent columns equal to half the length of the longest wavelength of the target wavelength range of the first dispersion structure (300a) (which may be the target wavelength (409)). A quasi-random pattern may be achieved using inverse transformation sampling for a uniform distribution. The quasi-random pattern may allow for low or no spatial correlation between neighboring nanostructure columns (403a-403n). If there is low or no spatial correlation, this may allow the angle range (401, incident angle range) to allow for a constant output scattering range of light across the first angle range (412) and the second angle range (413). The random distribution of nanostructure rows (403a-403n) along the X-axis direction allows the nanostructure layer (402) to operate independently of the polarization of the incident light (201) of FIG. 4, as there is no row pattern and therefore no dependence of light on the pattern.

[0086] In one embodiment, nanostructure columns such as 403a may contain nanoholes (601a-601n). Each nanostructure column (403a-403n) may contain copies of a set of nanoholes (601a-601n). The nanoholes (601a-601n) may have similar radii, thicknesses, and distances between adjacent nanoholes within the target nanostructure column such as 403a. In one embodiment, the nanoholes (601a-601n) may have a radius of 140 nm and a depth of 750 nm, but may be larger or smaller than this.

[0087] In one embodiment, the nanoholes (601a-601n) may be spaced approximately equally apart from each other. The nanoholes (601a-601n) may be placed adjacent to each other so that light can pass through with little or no scattering in the Z-axis direction. To allow light to pass through with little or no scattering in the Z-axis direction, the following conditions must be satisfied:

[0088]

[0089] wavelength If is the wavelength of interest, It may be the refractive index of the nanoholes (601a-601n), and d ≠ the distance between adjacent nanoholes (601a-601n). For example, the nanoholes (601a-601n) may have a distance of 10 nm to 200 nm between adjacent nanoholes of the first nanostructure column (403a) and may have a refractive index of about 1.5, which may allow scattering of both visible light and near-infrared (NIR). Non-scattering or low-scattering conditions may be used in the design of the one-dimensional structure described below.

[0090] The one-dimensional structure can provide a one-dimensional pattern, such as the distribution of nanostructure columns (403a-403n) along the X-axis direction. The pattern may be a repeating or random distribution of nanostructure columns (403a-403n), which will be discussed in more detail later. The one-dimensional structure can maintain consistency in two dimensions, such as maintaining the same number or arrangement of nanoholes (601a-601n) between nanostructure columns (403a-403n) along the Z-axis direction; the same number or arrangement of nanoholes (601a-601n) may be repeated for each nanostructure column (403a-403n).

[0091] The two-dimensional structure can provide patterning in both the one-dimensional and two-dimensional dimensions. For example, nanostructure columns (403a-403n) may have a pattern along the X-axis direction. As previously mentioned, the pattern may be nanostructure columns (403a-403n) randomly distributed between a minimum distance and a maximum distance along the X-axis direction. Additionally, the first nanostructure column (403a) may have nanoholes (601a-601n) patterned in the Z-axis direction within the column. For example, the first nanostructure column (403a) may have nanoholes (601a-601n) having a pattern of different diameters, shapes, thicknesses, and spacing between each nanohole (601a-601n).

[0092] As described above, light can be scattered in one direction through the first dispersion structure (300a), which may follow the X-axis direction of FIG. 6 (perpendicular to the nanostructure rows (403)), but may not be substantially scattered along the direction parallel to the nanostructure rows (403a-403n) shown in the Z-axis direction. This uniaxial scattering may be due to the proximity between the nanoholes (601a-601n) along the Z-axis direction, which allows light to pass through substantially without scattering because the distance between the nanoholes (601a-601n) is smaller than the wavelength of the incident light (201). Scattering may occur along the X-axis direction because the nanostructure rows (403a-403n) are spaced far enough apart (according to a quasi-random distribution) so that light of a specific wavelength does not pass through without scattering.

[0093] Specifically, the radius r of the first nanohole (601a) is phase-shifted to the incident light (201). i It can be imparted, which can result in a near-field response (411) as illustrated in FIG. 4 and described above. The near-field response (411) of an individual nanohole, such as the first nanohole (601a), is It may be referred to as. The near-field response (411) of FIG. 4 may include the sum of the near-field responses (411) of the nanoholes (601a-601n) for all nanostructure columns (403a-403n) of FIG. 6.

[0094] Due to Mie scattering, a larger radius r of the first nanohole (601a) may allow more scattering, and a smaller radius may allow less scattering. Light scattered by a single first nanohole (601a) may be scattered in a conical shape. In one embodiment, the radius r may be about 140 to 150 nm; however, the radius may be larger or smaller depending on the target wavelength (409). As discussed below, when the nanoholes (601a-601n) form the first nanostructure row (403a), light may pass through and not be substantially dispersed in the Z-axis direction due to the proximity of the nanoholes (601a-601n) in the Z-axis direction.

[0095] When nanostructure columns (403a-403n) are distributed in the X-axis direction, scattering of the incident light (201) of FIG. 4 can be restricted in the X-axis direction. By selecting the radius r of the nanoholes (601a-601n) and distributing the nanostructure columns (403a-403n) semi-randomly, the nanostructure columns (403a-403n) can be designed to scatter light at selected wavelengths and selected angles due to Mie scattering. The average distance between all nanostructure columns (403a-403n) can determine whether light is scattered and at what wavelength it is scattered.

[0096] In one embodiment, the distribution of the rows may depend on the density of the nanostructure rows (403a-403n). The density of the nanostructure rows (403a-403n) may be the surface area of ​​the nanoholes (601a-601n) divided by the total surface. For a one-dimensional configuration, the density may be higher when the nanostructure rows (403a-403n) are spaced closer together, and lower when the nanostructure rows (403a-403n) are spaced further apart. The spacing between the nanostructure rows (403a-403n) may be known as row density. Row density may be the number of nanostructure rows (403a-403n) per unit length on the first dispersion structure (300a) and may be used to determine the density for the one-dimensional configuration. By changing the heat density, the efficiency of the first dispersion structure (300a) can be changed.

[0097] When the sensor (200) reads image and spectrum data, the efficiency may be the ratio of the intensity of the scattered light (410) to the intensity of the incident light (201) in the spectrum reading angle range (414). When the sensor (200) reads only spectrum data, the efficiency may be the value obtained by dividing the intensity of the scattered light (410) to the intensity of the incident light (201) in the second angle range (413). The intensity may be measured in units of lux. The efficiency may be known as non-specular forward-scattering light that is scattered and spectrally read by the image sensor (206) relative to the intensity of the incident light (201). The efficiency may be used to determine the density of the nanostructure rows (403a-403n). Specular forward-scattering light, as opposed to non-specular light, may include zero-order transmitted light, which may be scattered light (408). The non-specific forward scattered light may include higher-order or non-zero-order transmitted light, which may be light dispersed at a non-zero angle. An image sensor (206) can read the spectrum of the non-specific reflected light. Higher efficiency can increase the scattering probability of the incident light (201). Determining the scattering of the incident light (201) may depend on the target wavelength (409), hole density, and heat density, as described in more detail below.

[0098] To determine the efficiency of the first dispersion structure (300a) for a given density of nanostructure columns (403a-403n), the near-field response (411) of the nanohole (601a-601n) analysis can be performed as described below. Near-field response (411) It may depend on the radius of the nanoholes (601a-601n) used. The collective near-field responses (411) of the nanoholes (601a-601n) can be used to determine the thermal density of the nanostructure rows (403a-403n) of the first dispersion structure (300a). The first nanohole (601a) has a radius can have, It may be similar across the nanoholes (601a-601n), which may follow the equation:

[0099]

[0100] Here, ≠ a phase transition of the incident light (201), i is an imaginary unit, R is the radius of the first nanohole (601a) where light can no longer be scattered, and R is half the width of the wavelength to be scattered. By determining the radii of the nanoholes (601a-601n), the density of the first dispersion structure (300a) can be determined.

[0101] At higher heat densities of nanostructure columns (403a-403n), the amount of scattering of incident light (201) can be reduced due to subwavelength conditions. As further explained below, the average distance between adjacent nanostructure columns (403a-403n) d A subwavelength condition may occur as the maximum value of the subwavelength of half the target wavelength (409) decreases to 0 nm.

[0102] The heat density, including the distribution and average distance between adjacent nanostructure rows (403a-403n), can be determined by the target wavelength (409) of the incident light (201) that can be scattered. The maximum distance between adjacent nanostructure rows (403a-403n) can be closer to each other than the subwavelength of the target wavelength (409) of the incident light (201). For example, at a wavelength of 800 nm, the subwavelength can be 400 nm, and the maximum distance between adjacent nanostructure rows (403a-403n) can be 400 nm. At a wavelength of 800 nm, if adjacent nanostructure rows (403a-403n) are within 400 nm of each other, the 800 nm wavelength can be scattered. If the distance between two adjacent nanostructure columns (403a-403n) is closer to a maximum distance of 400 nm, there may be more scattering. If the distance between two adjacent nanostructure columns (403a-403n) is closer to a distance of 0 nm, there may be less scattering. Therefore, when designing the arrangement of nanostructure columns (403a-403n), the column density can affect the scattering efficiency. Additionally, if there is a pattern in the arrangement of nanostructure columns (403a-403n), light scattering may depend on the pattern of the nanostructure columns (403a-403n). For example, if the nanostructure columns (403a-403n) are spaced uniformly or in a repeating pattern, scattering of the target wavelength range may occur at a fixed angle for each wavelength and may not occur over the first angle range (412) or the second angle range (413). Thus, the arrangement of the nanostructure columns (403a-403n) is a semi-random uniform distribution using inverse transform sampling, and can generate a random distribution between the minimum distance and the maximum distance.

[0103] In some embodiments, the distribution of nanostructure columns (403a-403n) is a probability density function It can be determined by. The probability density function can be used to provide boundaries for the randomized placement of each column.

[0104] In some embodiments, the Fourier transform of the probability distribution of the nanostructure columns (403a-403n) is It can be recorded as. The Fourier transform of the probability density function can be used to determine how the nanostructure columns (403a-403n) are distributed randomly or semi-randomly. The Fourier transform can be a characteristic function of the distribution of the nanostructure columns (403a-403n). Fourier transform The distribution of the rows of silver nanostructures (403a-403n) is scattered light It can be used to construct a random distribution of nanostructure rows (403a-403n) so as to be independent of scattered light (408), which can be represented as such.

[0105] By using a Fourier transform to construct a random distribution, a semi-uniform random distribution of nanostructure columns (403a-403n) is generated, which can ensure there is no spatial correlation between neighboring nanostructure columns (403a-403n). The lack of spatial correlation between neighboring nanostructure columns (403a-403n) allows for various angle ranges (401, incident angle range), thereby allowing for a constant output scattering range of light across a first angle range (412) and a second angle range (413).

[0106] Specular term of transmitted light It can provide position information of scattered light (408), which can be used to construct an incident image. The position information of scattered light (408) and dispersed light (410) can allow simultaneous imaging and spectroscopy from the first dispersion structure (300a). In some embodiments, it may be advantageous to optimize the scattering of light at large angles for angle-independent spectroscopy.

[0107] FIG. 7 illustrates a design analysis of the one-dimensional configuration of the first dispersion structure (300a). This illustrates an exemplary efficiency-to-density relationship for the first dispersion structure (300a) having a target wavelength range of 700 nm to 725 nm. In some embodiments, there is a relationship between the efficiency of the near-field response (411) of FIG. 4 and the different total densities of the nanostructure columns (403a-403n) of FIG. 6. The efficiency relationship can be used to determine the thermal densities of the nanostructure columns (403a-403n).

[0108] FIG. 8 illustrates a top view of an exemplary nanostructure layer (402) that may include nanoantennas (801) and may be used as an alternative embodiment for the nanoholes (601a-601n) of FIG. 6. The nanoantennas (801) may have subwavelength thicknesses. In one embodiment, a subwavelength of half the target wavelength (409) may be used. The nanoantennas (801) may be made of a plasmonic material or a dielectric material. The nanoantennas (801) may manipulate light through spatially arranged meta-atoms. A meta-atom may be an atomic part of a structured pattern, such as a hole, an antenna, or other shape. The nanoantennas (801) may be antennas with a size of about 10 nm to 1000 nm.

[0109] Plasmonic materials can include metals, transparent conductive oxides, transition metal nitrides, or 2D materials. Plasmonic nanoantennas can interact with light through plasmon resonance. During interaction, electrons in plasmonic nanoantennas can move from their steady-state positions due to an external electric field, which can be known as polarization. The polarization of electrons can form an internal field to restore the electrons to a steady state. Under the influence of an external electric field, electron oscillations can generate a phase shift of pi across the spectral width of the plasmon resonance. Precious metals such as gold and silver can be used as construction materials for plasmonic structures. Additional modifications can be utilized, such as creating V-shaped nanoantennas to support two resonance modes and incorporating a metal ground plane separated from the nanoantenna array by a thin dielectric spacer. By adding a thin dielectric spacer, the incident light can induce an antiparallel current between the nanoantenna (801) and the ground plane, which can generate gap resonance and provide a phase shift of 0 to 2 pi.

[0110] Plasmonic nanoantennas can be fabricated by focused-ion beam milling. A plasmonic nanoantenna structure can be created by milling a thin metal layer in a focused ion beam. The nanoantennas (801) can be dielectric nanoantennas or dielectric nanoholes. Dielectric nanoantennas or nanoholes can manipulate light through Mie scattering. Dielectric nanoantennas can also be fabricated using electron beam (e-beam) lithography and electron beam evaporation.

[0111] FIG. 9 illustrates an example of a graph illustrating the light dispersion efficiency at various wavelengths for an embodiment of the dispersion array (204) of FIG. 2. The efficiency response for the first wavelength band may be the response (901a) corresponding to the first dispersion structure (300a). Subsequent responses (901b-901n) may be related to subsequent dispersion structures (300b-300n). FIG. 9 can be used to construct and verify the efficiency of the dispersion structures (300a-300n), each of the nanostructure columns (403a-403n) of FIG. 6. Additionally, the efficiency may be used to calibrate the dispersion structures (300a-300n). It may also be used for spectroscopy purposes. When an image is read by the sensor (200) of FIG. 2, the spectral response portion may be interpreted by referring to an efficiency graph such as FIG. 9.

[0112] In this example, the dispersion array (204) may include n=8 dispersion structures (300a-300n) capable of cumulatively providing dispersion efficiency for light with a wavelength of about 700 to 900 nm. The dispersion structures (300a-300n) of FIG. 3 may each have a dispersion efficiency response corresponding to 901a-901n.

[0113] FIG. 10 shows various dispersion output angles of the dispersion light (410) of FIG. 4. i Each intensity dispersion curve is plotted, which is the result of an exemplary embodiment of a dispersion structure such as 300a-300n. The illustrated wavelength-dependent dispersion angle can be used when designing the parameters of the nanostructure layer (402) of FIG. 4 (e.g., when designing a specific dispersion structure such as 300a), and can also be used when designing an image sensor (206). In one example, FIG. 10 may show each intensity dispersion of a first dispersion structure (300a) having a target wavelength range of dispersion light (410) between 800 nm and 835 nm. A wavelength of 835 nm can pass through the exemplary first dispersion structure (300a) with a dispersion of 0°. A dispersion output angle of approximately + / - 30°. i It may correspond to a wavelength range of 800 nm to 835 nm, which may be a second angle range (413). In one embodiment, the second angle range (413) may be used for spectroscopy. In another embodiment, the first angle range (412) may be a wavelength used for imaging rather than spectroscopy. The first angle range (412) may be + / - 15°. The spectrum readout angle range (414) may be + / - 15° to + / - 30°.

[0114] For other dispersion structures such as 300b-300n, there may be different target wavelength ranges of the dispersion light (410), and thus, different wavelengths may be dispersed at specific angles (e.g., + / - 30°).

[0115] From a design perspective, the dispersion angle of each wavelength can be fitted to an exponentially expanded Lorentzian distribution, and as a result, a graph similar to Figure 10 can be generated.

[0116] The peak position for the wavelength can be extracted from the fitting of the exponentially expanded Lorentz distribution. Then, the peak position corresponds to the target wavelength (409) for the dispersed light (410) and the refractive index for the filter layer (404). n To extract *, it can be fitted to the equation below. To determine the characteristics of the first dispersion structure (300a), the full-width at half maximum (FWHM) of the fitting for the dispersion angle and wavelength can be considered in the calculation below. Dispersion angle of the dispersed light (410) is dispersed light (410)( l 0) target wavelength (409) and refractive index of filter layer (404) n Can depend on:

[0117]

[0118] In some embodiments, these peak positions can be used to determine the target wavelength (409) of the dispersed light (410), which can be used to create a dispersed array (204) having dispersed structures (300a-300n).

[0119] FIG. 11 illustrates an image sensor (206) of FIG. 2 viewed from the side, with incident light (201) that passes through the center of the image sensor (206) and defines the central axis after passing through the aperture (202) and dispersion array (204) (and possibly a lens (205)) of FIG. 2 at a specific height (away from the page). The image sensor (206) includes an inner region (208) and an outer region (209), each containing a plurality of pixels. The inner region (208) includes a first set of pixels in a first angular range (412) from the axis of the incident light (201) traveling from the dispersion array (204) and lenses (205), whereas the outer region (209) includes a second set of pixels in a larger second angular range (413) from the axis of the incident light (201) traveling from the dispersion array (204) and lenses (205) that is not yet included by the inner region (208). The inner region (208) and the outer region (209) of the image sensor (206) can read imaging and spectral data from the dispersion structures (300a-300n) of FIG. 3, as shown in FIG. 12.

[0120] More specifically, in certain embodiments, the inner region (208) may be used to image scattered light (408), and the outer region (209) may be used to read the spectrum of scattered light (410). In certain embodiments, the inner region (208) may be a set of pixels logically grouped into a circle, and the outer region (209) may be a set of pixels logically grouped together as a ring coaxial with the inner region (208). In other embodiments, the inner region (208) and the outer region (209) may be used together to read only the spectrum data.

[0121] More specifically, the filter layer (404) is recalled to be able to pass light of a specific wavelength within a first angle range (412) (e.g., scattered light (408)) and scattered light (410) of a selected set of different wavelengths within a second angle range (413) without dispersion, with an accurate dispersion angle based on the wavelength of light. Since only light dispersed at an angle dependent on the wavelength reaches these pixels, spectrum reading can be performed using sensor pixels in the outer region (209).

[0122] Because the inner region (208) receives light that undergoes reduced scattering and contains only a portion of the spectral dispersion light (410), imaging data can be read from all the received light within it.

[0123] For example, if the first angle range (412) is 0° to + / - 15° and the second angle range (413) is 0° to + / - 30°, the inner region (208) can image visible light in the range of 0° to + / - 15° and the outer region (209) can read near-infrared (NIR) light in the range of 15° to + / - 30°.

[0124] FIG. 12 illustrates a composite image (1201) that can be illuminated by incident light (201). In one embodiment, the incident light (201) may include visible light or near-infrared (NIR) broadband light.

[0125] The composite image (1201) may appear to have a center with stripes radiating from the center toward the edges. The composite image (1201) may be false color for illustrative purposes. The composite image (1201) may be a false color representation of an image captured by a monochrome sensor, and the color may represent the intensity or brightness of the image. The composite image (1201) may appear blurry due to both scattering of light (scattered light (408)) and dispersion of light (dispersed light (410)). Stripes such as 1204 may be the result of light being scattered along a single axis from one of the dispersion structures (light dispersion mechanisms, 300a-300n).

[0126] Referring to FIG. 3, each dispersion structure (300a-300n) can scatter and disperse light in one dimension. For example, the dispersion structures (300a-300n) can scatter and disperse light along an axis perpendicular to the nanostructure rows (403) containing the dispersion structures (300a-300n). Because each dispersion structure (300a-300n) is at a different angle from the other dispersion structures (300a-300n), each dispersion structure (300a-300n) creates a unique fringe in a defined direction corresponding to the arrangement of the dispersion structures (300a-300n) within the dispersion array (204). FIG. 12 illustrates dispersion structures (300a-300n) where n=8, and the scattered and dispersed light streaks shown in the composite image (1201) are all spaced 22.5° apart from each other, each corresponding to the dispersion structure angles (301a-301n).

[0127] Each dispersion structure (300a-300n) may be configured to disperse incident light (201) within a defined set of target wavelength ranges (partially based on each target wavelength (409) and the dimensions of the defect layer (407) as discussed above). As previously mentioned, each dispersion structure (300a-300n) may generate unique linear stripes of dispersed spectral light, such as the stripe (1204) for the first dispersion structure (300a). Additionally, as discussed above, each stripe may occur at a uniquely known location and direction due to the physical coupling of the image sensor (206) and the dispersion array (204). Finally, within each stripe, each specific wavelength is dispersed at a known angle corresponding to a known distance from the center of the image. Thus, each wavelength of light received within the entire target wavelength range of the dispersion array (204) may reach a known area on the image sensor (206), and thus on a known pixel. From this information, the accurate determination of the spectral composition and strength of a given optical signal can be made based on the signal received from the corresponding pixel.

[0128] After the composite image (1201) is read by the image sensor (206), the image (1202) and spectrum data (1203) can be extracted. In one embodiment, the image (1202) may be a visible image, and the spectrum data (1203) may be an NIR spectrum. A post-processing algorithm may be applied to extract the image (1202) and spectrum data (1203).

[0129] To reconstruct the image, post-image processing may be used to remove artifacts induced by scattering. In some embodiments, this may include applying a deblurring algorithm based on the correction of dispersion structures (300a-300n). In some embodiments, this may include measuring the point-spread function (PSF) by measuring the transmission angle intensity through each dispersion structure (300a-300n) when illuminated by collimated visible light (400-650 nm). The measured point-spread function (PSF) may be deconvolved from the raw image using the Richardson-Lucy algorithm. Ten iterations may be used to provide a balance between deblurring and the removal of ringing artifacts.

[0130] To reconstruct the measured spectrum, in some embodiments, the following procedure may be used. The spectrum can be extracted from the spectral region of the raw data by fitting the raw data according to an ideal model of the wavelength-dependent scattering fringes of the dispersion structures (300a-300n). When incident light (201) affects the dispersion structures (300a-300n), first, the incident light (201) may be scattered at different angles depending on the direction of the first dispersion structure (300a) and the initial angle of the light. Second, the light may be filtered and scattered at a series of angles depending on the spectral content of the light (e.g., wavelength).

[0131] Therefore, the angles of incident light ( ) and position on the detector x, y Scattering intensity distribution for It can be modeled. An ideal dispersion structure (300a-300n) can scatter equally to all pixels along the dispersion structure angles (301a-301n). Therefore, can be defined as follows:

[0132]

[0133] Here, is the focal length of the focusing lens, and θ can be the angle at which the axes of the dispersion structures (300a-300n) are oriented. For a given image, the total scattering intensity distribution may be as follows:

[0134]

[0135] Here is the intensity distribution of the image taken as an input variable in the model.

[0136] Spectral intensity The filtering effect at and other angles can be explained as follows. Given angle About Only the target wavelength range of the dispersed light (410), which can be known as, is given for the first dispersion structure (300a) angle It can be transmitted. Therefore, pixel location x, y The spectrum filtering function can be defined as follows:

[0137]

[0138] Here, The pixel location of an optical system that can be written as follows x, y It can be an angle corresponding to:

[0139]

[0140] Finally, the overall stripe pattern for the dispersion structure (300a-300n) can be calculated by multiplying the spectral filtering by random scattering to obtain the final spectral stripe pattern:

[0141]

[0142] The same calculation can be repeated for each of the n dispersion structures (300a-300n), and then the intensity patterns are summed together to obtain the final spectral stripe pattern from the model.

[0143] To calculate the spectrum from the measured stripe pattern, in some embodiments, the acquired model has, for example, a tolerance of 10 -6 It can be fitted to raw data using the least squares fit method (LSQR).

[0144] As mentioned above, the ideal dispersion structure (300a-300n) accounts for scattering and transmission efficiencies independent of angle. However, in reality, slight variations in intensity with respect to angle may be observed because scattering can be completely random. Additionally, high-angle light may be transmitted through the filter less efficiently than low-angle light due to Fresnel reflection. Furthermore, transitions to different wavelengths within a single dispersion structure (300a-300n) can introduce additional errors. To correct this, a wavelength-dependent correction term was multiplied across the spectrum.

[0145]

[0146] Here, is the corrected spectral intensity, and is the correction factor. To calculate, the spectrum measured using a high-resolution commercial spectrometer is the spectrum measured by the dispersion structures (300a-300n) for unfiltered incident light It can be divided into. This coefficient can be used to calculate the spectrum using dispersion structures (300a-300n), which shows good agreement with the measurement of a reference spectrometer.

[0147] Since the correction considers the non-constant scattering of the dispersion structure (300a-300n), it can vary depending on the angle of incidence of light and therefore depending on the incident image of light. Therefore, for each angle of incidence The separate calibration matrix can be measured and used for each image used. However, in a more general setting where the image is not a priori known, arbitrary calibration coefficients for any image can be calculated using the linearity of the system as follows:

[0148]

[0149]

[0150] Finally, using the definition of the correction factor, the total correction factor can calculate:

[0151]

[0152] thus, When pre-correction is performed to measure, the total correction coefficient for any incident image obtained using dispersion structures (300a-300n) It can be calculated. Once fully calibrated (e.g., after production in a factory), the sensor (200) integrating the dispersion array (204) and dispersion structures (300a-300n) can be used to measure the spectrum in the field.

[0153] FIG. 13 illustrates a manufacturing process (1300) of a distributed array (204). More specifically, it illustrates a process for forming a structure (510-515) graphically illustrated in FIG. 5. The manufacturing process (1300) may be a monolithic process.

[0154] Referring to FIGS. 4 and 5, the first process (1301) may include depositing a first layer (405) on a substrate (501). The first layer (405) may include a first material. In one embodiment, the first layer (405) may be TiO2 and may be deposited via sputtering, but other materials and deposition techniques may also be used. TiO2 sputtering may be reactive sputtering, magnetron sputtering, RF magnetron sputtering, or other techniques. Other deposition techniques may include, but are not limited to, a sol-gel method, pulsed laser deposition, molecular-beam epitaxy, or atomic layer deposition.

[0155] The second process (1302) may include depositing a second layer (406) on the first layer (405) as described above. In one embodiment, the second layer (406) may be SiO2 and may be deposited via PECVD or SiO2 sputtering, but other materials or deposition techniques may also be used.

[0156] The third process (1303) may include alternately depositing the first and second layers (405, 406) after the second process (1302). That is, the processes (1301, 1302) may be repeated several times in turn to form a desired number of first and second layers (405, 406) and to alternately form a series of first and second layers (405, 406). The materials and designs of the first and second layers (405, 406) have been previously described in relation to FIG. 5.

[0157] The fourth process (1304) can deposit a defect preparation layer (504). In one embodiment, the defect preparation layer (504) may be SiO2 and may be deposited via PECVD, but other materials and deposition techniques may also be used. In one embodiment, the defect preparation layer (504) may be a thicker SiO2 layer. The thickness of the defect preparation layer (504) may be determined by the thickness of the defect layer (407) after processing the defect preparation layer (504).

[0158] The fifth process (1305) may include depositing one or more defect photolithography layers (503) on the defect preparation layer (504) after the fourth process (1304). The defect photolithography layer (503) may be a photoresist or a polymer.

[0159] The sixth process (1306) may apply UV exposure to the defect photolithography layer (503), which may penetrate the defect preparation layer (504). UV radiation may be applied over the range (508) of FIG. 5, and the total capacity of the UV exposure may vary over the range (508). Variable capacity power or variable time capacity of the UV exposure may be applied, which may form a variable thickness defect layer (407). For example, the variable capacity power levels for eight divisions may have power levels of x, 7 / 8x, 6 / 8x, and as low as 1 / 8x. The variable time capacity of the UV exposure may have the same power level x and may have times of t, 7 / 8t, 6 / 8t, and as low as 1 / 8t for each division. Together, the fifth and sixth processes (1305, 1306) may be known as grayscale photolithography techniques, but other techniques may also be used.

[0160] The seventh process (1307) may include etching the defect photolithography layer (503) and the defect preparation layer (504). In one embodiment, dry etching may be used, whereby a focused electron beam may strike the defect photolithography layer (503) and the defect preparation layer (504) to form the defect layer (407). Other etching techniques may also be used. The defect layer (407) may have a variable thickness (after the subsequent processing steps mentioned above) and may allow light dispersion at variable wavelengths due to the variable thickness. In one embodiment, the defect layer (407) may have eight different thicknesses, and the eight different thickness layers may allow wavelength dispersion in a sub-band of 2 to 5 nm.

[0161] In an alternative embodiment, as discussed in relation to FIG. 5, multiple rounds of etchant masking and etching may be performed to form a defect layer (407) from a defect preparation layer (504).

[0162] The eighth process (1308) may include depositing a first layer (405) on a defect layer (407) using the same technique as described in the first process (1301). The first layer (405) may contain the same material as in the first process (1301), and its thickness may be the same or different.

[0163] The ninth process (1309) may include depositing a second layer (406) using the same technique as described in the second process (1302). The second layer (406) may contain the same material as in the process (1302), and its thickness may be the same or different.

[0164] The 10th process (1310) may include depositing the first and second layers (405, 406) of the 8th and 9th processes (1308, 1309) alternately one or more times as desired (i.e., to form a required number of repeating layers including the first and second layers (405, 406).

[0165] The eleventh process (1311) may include depositing a capping stack (506). In one embodiment, the capping stack (506) may include the material of the first layer (405) and may be deposited using the first process (1301) over a longer time period. The capping stack (506) may be TiO2 and may be deposited via a sputtering method. The capping stack (506) may be substantially thicker than the first and second layers (405, 406) and may be horizontal with respect to the initial layers / substrate to allow for the creation of nanostructures within it.

[0166] The 12th process (1312) may include depositing a lithography mask (507) on a capping stack (506). The lithography mask (507) may be a photoresist or a polymer.

[0167] The 13th process (1313) may apply radiation to a lithography mask (507) and may also penetrate a capping stack (506). The radiation may be electron beam (e-beam) lithography, UV exposure, or other radiation. The radiation may be applied to the lithography mask (507), and the total dose of the radiation may follow a pattern to create nanoholes (601a-601n) as shown in FIG. 6. Variable dose power or variable time dose of the radiation may be applied to form the nanoholes (601a-601n).

[0168] The 14th process (1314) may include etching the lithography mask (507) and the capping stack (506). In one embodiment, dry etching may be used, wherein a focused electron beam may collide with the lithography mask (507) and the capping stack (506) to form nanoholes (601-601n). Other etching techniques may also be used.

[0169] Embodiments of the invention and operations described herein may be implemented in digital electronic circuits, computer software, firmware, or hardware, including structures disclosed herein, structural equivalents thereof, and combinations of one or more of these. Embodiments of the invention disclosed herein may be implemented as one or more computer programs, namely, as one or more modules of computer program instructions encoded in a computer storage medium to be executed by a data processing device or to control the operation of a data processing device. Alternatively or additionally, program instructions may be encoded in an artificially generated radio signal (e.g., a machine-generated electrical, optical, or electromagnetic signal generated to encode information for transmission to a receiving device suitable for execution by a data processing device). The computer storage medium may be a computer-readable storage device, a computer-readable storage substrate, a random or serial access memory array or device, or a combination thereof, or may be included therein. Additionally, although the computer storage medium is not a radio signal, the computer storage medium may be a source or destination of computer program instructions encoded in an artificially generated radio signal. Additionally, a computer storage medium may be one or more individual physical components or media (e.g., multiple CDs, disks, or other storage devices) or may be included therein. Furthermore, the operations described herein may be implemented as operations performed by a data processing device on data stored in one or more computer-readable storage devices or received from other sources.

[0170] Although this specification may include many specific implementation details, such implementation details should not be interpreted as being limited to the scope of the claims, but rather as describing specific features of specific embodiments. Furthermore, specific features described in this specification in the context of separate embodiments may be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may be implemented individually or in any suitable subcombination in multiple embodiments. Moreover, while features may be described above as functioning as a specific combination and may even be initially claimed as such, one or more features from the claimed combination may be omitted from the combination as needed, and the claimed combination may lead to a subcombination or a variation of a subcombination.

[0171] Similarly, although operations are depicted in a specific order in the drawings, it should not be understood that such operations are required to be performed in the specific order depicted or in a sequential order, nor should it be understood that all depicted operations must be performed to achieve the desired result. In certain situations, multitasking and parallel processing may be advantageous. Furthermore, the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments, and the described program components and systems may generally be combined into a single software product or packaged into multiple software products.

[0172] Accordingly, specific embodiments of the invention have been described in this specification. Other embodiments are within the scope of the claims set forth below. In some cases, the operations specified in the claims may be performed in a different order, and a desirable result may nevertheless be obtained. Additionally, the process illustrated in the accompanying drawings does not necessarily require the specific order or sequential order illustrated to obtain a desirable result. In certain embodiments, multitasking and parallel processing may be advantageous.

[0173] As is recognized by those skilled in the art, the innovative concepts described herein may be modified or varied over a wide range of applications. Accordingly, the scope of the claimed invention should not be limited to any of the specific exemplary teachings discussed above, but is instead defined by the claims set forth below.

[0174] Embodiments of the concept of the present invention may be extended without limitation to the following statements:

[0175] Statement 1: An image sensor comprising an aperture; a dispersion array; a lens; an image sensor; and a processor.

[0176] Statement 2: In Statement 1, the dispersion array further comprises one or more dispersion structures, and the dispersion structure is an image sensor capable of scattering light in a first wavelength range and dispersing light in a second wavelength range.

[0177] Statement 3: In Statement 2, at least two dispersion structures include a defect layer, and the defect layers of the at least two dispersion structures have different thicknesses, in an image sensor.

[0178] Statement 4: In Statement 3, the dispersion structure comprises at least two dispersion structures that disperse different wavelength ranges, in an image sensor.

[0179] Statement 5: An image sensor according to Statement 3, wherein the dispersion structures scatter light in a first direction but allow it to pass substantially without scattering it in a second direction.

[0180] Statement 6: In Statement 3, the image sensor comprising at least two dispersion structures arranged at different angles, wherein the dispersion structures include rows of nanostructures.

[0181] Statement 7: In Statement 3, the image sensor comprising at least two dispersion structures arranged at the same angle to each other, comprising rows of nanostructures.

[0182] Statement 8: In Statement 1, the image sensor is an image sensor that reads spectral data from wavelengths dispersed by the dispersion array.

[0183] Statement 9: In Statement 8, the processor is an image sensor capable of reconstructing a spectrum from the spectrum data.

[0184] Statement 10: In Statement 1, the image sensor is an image sensor logically subdivided to read image data from a first pixel set and read spectrum data from a second pixel set.

[0185] Statement 11: An image sensor according to Statement 10, wherein the first pixel set comprises a circle, and the second pixel set comprises a ring coaxial with the circle of the first pixel set.

[0186] Statement 12: In Statement 10, the processor is an image sensor that reconstructs an image from the image data or reconstructs a spectrum from the spectrum data.

[0187] Statement 13: In Statement 1, the dispersion array is an image sensor that provides a constant scattering and dispersion angle range for an incident light input over a range of incident light input angles.

[0188] Statement 14: An image sensor according to Statement 1, wherein the incident light input angle range is 0 to + / - 15°.

[0189] Statement 15: An image sensor according to Statement 2, wherein the scattering and dispersion angle range is 0 to + / - 15° for the first wavelength range and 0 to + / - 30° for the second wavelength range.

[0190] Statement 16: In Statement 1, the lens is an image sensor that is a metalens.

[0191] Statement 17: In Statement 1, the aperture, the dispersion array, and the lens are integrated together in an image sensor.

[0192] Statement 18: A method for obtaining data from a sensor comprising: receiving incident light; scattering said incident light through a scattering layer to generate scattered light; dispersing a subset of said scattered light through a dispersing layer to generate dispersed light; receiving said dispersed light in an image sensor; and reconstructing spectral data from said dispersed light.

[0193] Statement 19: A method in which, in Statement 18, the incident light comprises light from the visible light or near-infrared (NIR) spectrum.

[0194] Statement 20: A method according to Statement 18 further comprising receiving the scattered light from the image sensor; and reconstructing an image from the scattered light.

[0195] Statement 21: In Statement 18, the spectrum data comprises light from the near-infrared (NIR) spectrum.

[0196] Statement 22: A method in which the incident light in Statement 18 is scattered by the scattering layer comprising a nanostructured surface.

[0197] Statement 23: A method in which the subset of the scattered light in Statement 18 is dispersed by a distributed Bragg filter.

[0198] Statement 24: In Statement 18, the method by which image and spectral data are reconstructed simultaneously.

[0199] Statement 25: A dispersion array comprising at least one dispersion structure that disperses light in a target wavelength range starting with 0° dispersion of the target wavelength, wherein the dispersion structure comprises a nanostructure layer and a filter layer.

[0200] Statement 26: In Statement 25, the nanostructure layer is a dispersed array comprising nanoholes, nanorods, or nanoantennas.

[0201] Statement 27: In Statement 25, the nanostructure layer is a dispersed array that is a dielectric or plasmonic material.

[0202] Statement 28: In Statement 25, the dispersion structure is a dispersion array adjusted to scatter and disperse light associated with the target wavelength range.

[0203] Statement 29: In Statement 25, the nanostructure layer further comprises nanostructure rows, each of which is a dispersed array parallel to one another.

[0204] Statement 30: In Statement 29, each of the above-mentioned nanostructure columns is a dispersed array further comprising nanoholes.

[0205] Statement 31: In Statement 30, the nanoholes are a dispersed array in a layer of TiO2.

[0206] Statement 32: In Statement 30, a dispersion array in which the radius of the nanoholes is less than or equal to half the target wavelength in the target wavelength range of the dispersion structure.

[0207] Statement 33: A dispersion array according to Statement 30, wherein each of the nanoholes is spaced sufficiently close to one another within the nanostructure column so that the target wavelength range can pass through the nanostructure column in one dimension with little or no scattering.

[0208] Statement 34: In Statement 29, the nanostructure columns are a dispersed array distributed between a minimum distance and a maximum distance.

[0209] Statement 35: In Statement 31, the nanostructure columns are a dispersed array randomly distributed between a minimum distance and a maximum distance.

[0210] Statement 36: In Statement 34, the maximum distance between the rows of nanostructures is half the target wavelength length of the dispersion structure.

[0211] Statement 37: In Statement 25, the filter layer comprises a distributed array including a distributed Bragg reflector, a dielectric mirror, a fiber Bragg grating, or a semiconductor Bragg mirror.

[0212] Statement 38: In Statement 25, the filter layer comprises a dispersion array including at least a first layer of a first thickness and a first material and a second layer of a second thickness and a second material, which are alternately stacked to form a stack layer.

[0213] Statement 39: A dispersed array in which, in Statement 38, the first layer comprises TiO2 and the second layer comprises SiO2.

[0214] Statement 40: In Statement 38, a distributed array having at least two sets of the stack layers.

[0215] Statement 41: In Statement 38, the stack layers are a dispersion array capable of dispersing light of a target wavelength of the dispersion structure.

[0216] Statement 42: In Statement 38, the dispersion array comprises two or more dispersion structures, and at least one dispersion structure comprises a defect layer.

[0217] Statement 43: In Statement 42, the dispersion array comprises multiple dispersion structures including the defect layers, and at least two dispersion structures are dispersion arrays having the defect layers of different thicknesses.

[0218] Statement 44: A method for manufacturing a dispersion array comprising depositing a first filter stack on a substrate; depositing a defect layer; depositing a second filter stack; depositing a capping stack; and forming a nanostructure from the capping stack.

[0219] Statement 45: A method for manufacturing a dispersion array according to Statement 44, wherein depositing the first filter stack comprises depositing at least one first layer of a first material composition and at least one second layer of a second material composition.

[0220] Statement 46: A method for manufacturing a dispersion array in which, in Statement 45, the first layer is a dielectric material having a refractive index between 1.3 and 1.6.

[0221] Statement 47: A method for manufacturing a dispersion array in which, in Statement 45, the second layer is a dielectric material having a refractive index between 1.6 and 2.7.

[0222] Statement 48: A method for manufacturing a dispersion array in which the defect layer of Statement 44 is etched by grayscale photolithography technology.

[0223] Statement 49: A method for manufacturing a dispersion array in which the defect layer of Statement 44 comprises the material used in the first filter stack.

[0224] Statement 50: In Statement 44, the nanostructure is a method for manufacturing a dispersion array formed through electron beam lithography or photolithography.

[0225] Statement 51: A method for manufacturing a dispersion array in which the nanostructure of Statement 44 is formed from one or more dispersion structures.

[0226] Statement 52: A method for manufacturing a dispersion array in which the defect layer of Statement 51 is etched to different thicknesses for multiple dispersion structures.

Claims

Claim 1 An image sensor comprising: an aperture; a dispersion array on the aperture; a lens on the dispersion array; an image sensor on the lens; and a processor connected to the image sensor, wherein the aperture, the dispersion array, the lens and the image sensor are integrated together, the dispersion array further comprises at least two dispersion structures, wherein the dispersion structures can scatter light in a first wavelength range and disperse light in a second wavelength range, wherein the at least two dispersion structures comprise a defect layer, wherein the defect layers of the at least two dispersion structures have different thicknesses, and wherein the at least two dispersion structures comprise rows of nanostructures arranged at different angles. Claim 2 delete Claim 3 delete Claim 4 In claim 1, the image sensor wherein the at least two dispersion structures disperse different wavelength ranges. Claim 5 An image sensor according to claim 1, wherein the at least two dispersion structures scatter light in a first direction but allow it to pass substantially without scattering it in a second direction. Claim 6 delete Claim 7 delete Claim 8 In claim 1, the image sensor is an image sensor that reads spectral data from wavelengths dispersed by the dispersion array. Claim 9 In claim 8, the processor is configured to reconstruct a spectrum from the spectrum data, an image sensor. Claim 10 In claim 1, the image sensor is a subdivided image sensor that reads image data from a first pixel set and reads spectrum data from a second pixel set. Claim 11 An image sensor according to claim 10, wherein the first pixel set comprises a circle, and the second pixel set comprises a ring coaxial with the circle of the first pixel set. Claim 12 In claim 10, the above processor is configured to reconstruct an image from the above image data or reconstruct a spectrum from the above spectrum data. Claim 13 In claim 1, the dispersion array is an image sensor that provides a constant scattering and dispersion angle range for incident light input over a range of incident light input angles. Claim 14 An image sensor according to claim 1, wherein the incident light input angle range is 0 to + / - 15°. Claim 15 An image sensor according to claim 1, wherein the scattering and dispersion angle range is 0 to + / - 15° with respect to the first wavelength range and 0 to + / - 30° with respect to the second wavelength range. Claim 16 In claim 1, the lens is an image sensor that is a metalens. Claim 17 delete Claim 18 A method for obtaining data from a sensor comprises: receiving incident light; scattering said incident light through a scattering layer to generate scattered light; dispersing said subset of said scattered light through a dispersing layer to generate scattered light; receiving said scattered light at an image sensor; reconstructing spectral data from said scattered light; receiving said scattered light at the image sensor; and reconstructing an image from said scattered light, wherein the image sensor is subdivided to read image data from a first set of pixels and to read spectral data from a second set of pixels, said first set of pixels includes a circle, and said second set of pixels includes a ring coaxial with said circle of the first set of pixels. Claim 19 In paragraph 18, the incident light comprises light from the visible light or near-infrared (NIR) spectrum. Claim 20 delete Claim 21 In paragraph 19, the method of reconstructing the spectrum data from light dispersed from the near-infrared (NIR) spectrum. Claim 22 In paragraph 18, the above incident light is scattered by the scattering layer comprising a nanostructured surface. Claim 23 In paragraph 18, the method wherein the subset of the scattered light is dispersed by a distributed Bragg filter. Claim 24 In paragraph 18, a method in which the image data and the spectrum data are reconstructed simultaneously.

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