Dispersion array and method of manufacturing the same

Abstract

A dispersion array and method of manufacturing the same are provided. Optical spectrometers can be used to determine the spectral components of electromagnetic waves. Spectrometers can be large, bulky devices and can require waves to enter at nearly a right angle for recording measurements. A nanophotonic component super-compact spectrometer employing optical dispersion techniques is disclosed. The nanophotonic component can include metasurfaces and Bragg filters. Each metasurface can include light scattering nanostructures that can be randomized to produce large input angles, and the Bragg filters can cause light dispersion independent of the input angle. The spectrometer can be capable of handling a bandwidth of about 200 nm. The super-compact spectrometer can be capable of reading image data within the visible light (400 nm to 600 nm) and capable of reading spectral data within the near-infrared (700 nm to 900 nm) wavelength range. The surface area of the spectrometer can be about 1 mm 2 , thereby making it suitable for mobile devices.

Description

Technical Field

[0001] The subject matter disclosed herein relates to spectrometers. For example, aspects of some exemplary embodiments relate to metasurface construction and fabrication methods, spectroscopy and imaging, and spectrometer components. Background Technology

[0002] Spectroscopy has become a key characterization technique in a wide range of applications, from scientific research to industrial and healthcare applications. Spectrometers generate spectral lines and can measure their wavelengths and intensities. Spectrometers use dispersive elements (such as diffraction gratings or prisms) to achieve wavelength-dependent angular dispersion, along with focusing optics that focus incident light onto a detector. These spectrometers are bulky and have low angular tolerances (angular tolerance is the angle at which incident light can enter the spectrometer and allow spectral analysis to be performed), which limits their use in mobile devices; therefore, there is a need for compact spectrometers with high angular tolerances.

[0003] The information disclosed in this background section is intended only to enhance the understanding of the disclosed background technology, and therefore may contain information that does not constitute prior art. Summary of the Invention

[0004] According to one example embodiment, an image sensor is provided, the image sensor including: an aperture, a dispersive array, a lens, an image sensor, and a processor.

[0005] According to another example embodiment, a method for obtaining spectral data from a sensor is provided, the method comprising: receiving incident light; scattering the incident light through a scattering layer to generate scattered light; dispersing a subgroup of the scattered light through the dispersing layer to generate dispersed light; receiving the dispersed light on an image sensor; and reconstructing spectral data from the dispersed light.

[0006] According to another example embodiment, a dispersion array is provided, the dispersion array comprising: at least one dispersion structure for dispersing light in a target wavelength range starting at 0° (degrees) dispersion of the target wavelength, wherein the dispersion structure further comprises: a nanostructure layer; and a filter layer.

[0007] According to another example embodiment, a method for fabricating a dispersive array is provided, the method comprising: depositing a first filter stack on a substrate; depositing a defect layer; depositing a cap stack; and forming a nanostructure from the cap stack. Attached Figure Description

[0008] In the following sections, aspects of the subject matter disclosed herein will be described with reference to exemplary embodiments shown in the accompanying drawings, in which:

[0009] Figure 1The operating principle of the spectrometer sensor is described.

[0010] Figure 2 The construction of an embodiment of a compact spectrometer is described.

[0011] Figure 3 A light dispersion array, as seen from a top view, is depicted according to some disclosed embodiments.

[0012] Figure 4 A cross-sectional view of a dispersive structure according to some disclosed embodiments is depicted.

[0013] Figure 5 Fabrication diagrams of layers and nanostructures formed according to some disclosed embodiments are depicted.

[0014] Figure 6 A top view of a dispersive structure according to some disclosed embodiments is depicted.

[0015] Figure 7 It is a graph depicting the density of nanostructures according to some disclosed embodiments and the efficiency of their metasurface optical dispersion.

[0016] Figure 8 A metasurface with nanoantennas according to some of the disclosed embodiments is depicted.

[0017] Figure 9 It is a graph depicting the processing of raw data into reconstructed images and spectral components, as well as the dispersion efficiency at varying wavelengths, according to some disclosed embodiments.

[0018] Figure 10 It is a graph depicting the angular response of dispersion to a selected wavelength in an example dispersion structure according to some disclosed embodiments.

[0019] Figure 11 An image sensor with a region having two detection pixels is depicted according to some disclosed embodiments.

[0020] Figure 12 The process of processing a raw image into spectral image data and visible image data according to some disclosed embodiments is described.

[0021] Figure 13 A manufacturing process for a dispersive structure according to some disclosed embodiments is described. Detailed Implementation

[0022] In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the disclosure. However, those skilled in the art will understand that the disclosed aspects can be practiced without these specific details. In other instances, well-known methods, steps, components, and circuits have not been described in detail to avoid obscuring the subject matter disclosed herein.

[0023] Throughout this specification, references to "an embodiment" or "an embodiment" indicate that a particular feature, structure, or characteristic described in connection with an embodiment may include in at least one embodiment disclosed herein. Therefore, the phrases "in an embodiment," "in an embodiment," or "according to an embodiment" (or other phrases with similar meanings) appearing in various places throughout this specification do not necessarily all refer to the same embodiment. Furthermore, a particular feature, structure, or characteristic may be combined in any suitable manner in one or more embodiments. Additionally, depending on the context of the discussion herein, singular terms may include corresponding plural forms, and plural terms may include corresponding singular forms.

[0024] It should also be noted that the various figures (including component diagrams) shown and discussed herein are for illustrative purposes only and are not drawn to scale. Similarly, various waveforms and timing diagrams are shown for illustrative purposes only. For example, the dimensions of some elements may be exaggerated relative to other elements for clarity. Furthermore, reference numerals have been repeated in the figures where appropriate to indicate corresponding and / or similar elements. The terminology used herein is for the purpose of describing some exemplary embodiments only and is not intended to limit the claimed subject matter. As used herein, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well. It will also be understood that when the terms “comprising” and / or “including” and variations thereof are used in this specification, it indicates the presence of the stated features, integrals, steps, operations, elements, and / or components, but does not preclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof. As used herein, the terms “first,” “second,” etc., serve as labels for nouns that follow them and do not imply any kind of ordering (e.g., spatial, temporal, logical, etc.) unless explicitly defined as such. Furthermore, the same reference numerals may be used throughout two or more figures to refer to parts, components, blocks, circuits, units, or modules having the same or similar functions. However, such use is merely for simplicity of description and ease of discussion; it does not mean that the construction or architectural details of such components or units are the same throughout all embodiments, or that such commonly referenced parts / modules are the only way to implement some of the exemplary embodiments disclosed herein.

[0025] It will be understood that when an element or layer is referred to as being "on" another element or layer, "connected to," or "bonded to" another element or layer, the element or layer may be directly on, directly connected to, or directly bonded to the other element or layer, or there may be intermediate elements or layers. Conversely, when an element is referred to as being "directly on" another element or layer, "directly connected to," or "directly bonded to" another element or layer, there are no intermediate elements or layers. The same reference numerals always refer to the same elements. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0026] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this subject pertains. It will also be understood that terms (such as those defined in a general dictionary) shall be interpreted as having a meaning consistent with their meaning in the context of the relevant field, and shall not be interpreted in an ideal or overly formal sense, unless expressly defined herein.

[0027] Figure 1 An example optical spectrometer 100 is shown. A light source 101 may be provided. The light source 101 may include both visible and invisible spectra, but it may also have a spectrum from long-infrared (or below) to gamma rays. The light source 101 can be used to describe any wavelength mentioned. The light source 101 may originate from a hot solid emitting light (which may or may not be absorbed by an intermediate substance that produces an absorption line), or it may originate from an emission spectrum, wherein the intensity and position of the spectral lines depend on the properties of the emitting substance and the cause of emission. The input to the light source 101 may be spatial light or light from an optical fiber. Light from the light source 101 passes through an entrance slit 102 with an incident light arrival angle 108. Depending on the aperture of the entrance slit 102, the incident light arrival angle 108 is typically between 0° and 2°.

[0028] The entrance slit 102 can have a square, rectangular, or other shaped aperture. The optical resolution and flux of the spectrometer can be determined by the entrance slit 102. Light entering the spectrometer can be focused onto the entrance slit 102, and the entrance slit 102 can be aligned with the light source 101 to allow light to pass through and reach other components. The slit width is typically between 5 μm and 800 μm and 1 mm to 2 mm high, but other dimensions are possible.

[0029] Once the light source 101 enters the entrance slit 102, it can be reflected by a collimating mirror 103 with a focal length 107, which can be the distance between the entrance slit 102 and the collimating mirror 103. The collimating mirror 103 can be a concave mirror. The collimating mirror 103 collects the light from the light source 101 and guides the light waves parallel to the diffraction grating 104.

[0030] A diffraction grating 104 can separate light guided by a collimating lens 103 into different wavelengths, and these different wavelengths can diffract at specific angles relative to each wavelength. These different wavelengths can pass through the diffraction grating 104 or can be reflected away at different diffraction angles. Different transmission gratings can be used for different wavelength ranges. The diffraction grating 104 can be a holographic grating or a scribing grating. A holographic grating can be developed by interfering two ultraviolet beams on a piece of optical glass, which then produces a sinusoidal refractive index change. A scribing grating can be developed by etching parallel grooves onto the surface of a substrate and then coating the parallel grooves with a reflective material. A scribing grating may produce more stray light due to surface imperfections. The number of grooves per unit length in a scribing grating and the groove width can affect the amount of dispersed light. The number of grooves per unit length in a scribing grating can be called the groove frequency or groove density. The wavelength coverage of a spectrometer with a diffraction grating 104 can be inversely proportional to the density of these grooves.

[0031] Once the light from light source 101 is dispersed and reflected by diffraction grating 104, it reaches focusing lens 105. Focusing lens 105 may be concave and focuses the light onto image sensor 106. Image sensor 106 may include pixels. Focusing lens 105 can form an image of light dispersed into selected wavelengths. Focusing lens 105 can reflect the dispersed light into light of varying wavelengths. Each ray of varying wavelengths may be at a different angle to diffraction grating 104 and focusing lens 105. These rays can reach pixels of image sensor 106, where each pixel receives a different wavelength based on the dispersion angle of the light. The image sensor used may depend on the wavelength being measured, which may include short-wavelength infrared (SWIR), near-infrared (NIR), visible light, ultraviolet (UV), X-rays, etc. These sensors can be charge-coupled devices (CCD), complementary metal-oxide-semiconductor (CMOS), n-type metal-oxide-semiconductor (NMOS), InGaAs, Si photodiode arrays with amplifiers, photomultiplier tubes (PMT), avalanche photodiodes (APD), or other sensors.

[0032] Light from the diffraction grating 104 (which can be reflected away by the focusing lens 105) propagates to the image sensor 106. The light interacts with pixels on the image sensor 106 to generate voltages. The size of the image sensor 106 can affect the field of view. The resolution of the image sensor 106 can be determined by the pixel density, pixel size, and the focal length of the focusing lens 105, which can be the distance between the focusing lens 105 and the image sensor 106. The focal length ratio (which is the focal length divided by the diameter of the focusing lens 105), the pixel size of the sensor, and the quantum efficiency (which can be measured by the conversion between the number of electrons in the image and the digital count) can determine the sensitivity of the image sensor 106. A processor (not shown) can analyze the voltages generated from the pixel group to interpret the spatial spectral distribution.

[0033] Because wavelengths may blur together in the diffraction grating 104, resonance shift may occur. Blurring can occur if two wavelengths diffract and overlap each other when read by pixels in the image sensor 106. Blurring may be caused by the resolution of the diffraction grating 104. If the gratings in the diffraction grating 104 are too thin or too closely spaced, or if light enters at an angle, wavelengths may overlap. When wavelengths overlap, the ability to read wavelengths is weakened. Resonance shift can result in poor signals, and the angular tolerance may be less than 2°. Figure 1 Spectrometers can provide only a spectrum. Due to design and space constraints, they may not be able to image a target simultaneously while providing a spectrum (this may require a separate set of optics and detectors specifically designed for this purpose).

[0034] Figure 1 While spectrometers in handheld devices can be used by technical experts for highly specialized applications, they are not suitable for consumer devices due to the size and cost of their components. Achieving high-performance, ultra-compact spectrometers that can be integrated into handheld devices such as smartphones could be beneficial. In addition to spectrometer performance parameters such as high resolution, high throughput, and a large spectral range, the large input angle tolerance of handheld spectrometers can also be advantageous. High angle tolerance increases the device's throughput and allows them to tolerate greater misalignment between the spectrometer and the spectral target, and also potentially a larger field of view. This can be beneficial for handheld applications where untrained users can hold the spectrometer in their hands and obtain good measurements without achieving the same precise alignment as practiced in a fixed laboratory environment.

[0035] Figure 2A sensor (e.g., spectrometer, spectrometer, and imaging device, etc.) 200 is depicted according to some embodiments of the present disclosure. Sensor 200 may be an ultra-compact spectrometer sensor. Sensor 200 may also be an ultra-compact combined imaging and spectrometer sensor. Incident light 201 may enter an aperture 202, and the aperture 202 may be used to focus the light onto a dispersive 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. Aperture 202 may be a triple lens providing near-field spectroscopy, but may also be other lens types. For example, aperture 202 may also be a slit similar to entrance slit 102 and may have a wider field of view, such as + / -30°. In one embodiment, the surface area of ​​the dispersive array 204 may be approximately 1 square millimeter, but it may be smaller or larger. Dispersive array 204 may include nanophotonic components.

[0036] As used herein, "scattering" can be defined as the deviation of light from its initial trajectory. "Dispersion" can be defined as light that can be separated into its constituent wavelengths. Dispersed light can also be scattered light.

[0037] The dispersive array 204 can scatter incident light 201 in a first wavelength range and a second wavelength range, which will be described in more detail later. The dispersive array 204 can allow light in the first wavelength range to pass through with little or no dispersion, and can disperse light in the second wavelength range. The dispersive array 204 can be integrated with the aperture 202 to allow the aperture 202 to be manufactured in the same process as the dispersive array 204.

[0038] Incident light 201, passing through aperture 202 and dispersive array 204, can then pass through lens 205. Lens 205 can focus the light onto image sensor 206. In one embodiment, lens 205 can be an optical lens, a metalens, or other lens. In an alternative embodiment, aperture 202 can be integrated with dispersive array 204 and lens 205. In yet another alternative embodiment, aperture 202, dispersive array 204, lens 205, and image sensor 206 can all be integrated together. In one embodiment, image sensor 206 can be used only to read spectral data. In another embodiment, image sensor 206 can be used to read both image data and spectral data. Image sensor 206 can have an inner region 208 and an outer region 209. Image sensor 206 can simultaneously read spectral data in a second wavelength range within outer region 209 and image data in a first wavelength range within inner region 208, which will be described in more detail below. Reading both image data and spectral data allows sensor 200 to distinguish between "real" and "fake" objects. For example, if the object being analyzed is a physical object, and a photograph of the object is presented to sensor 200, the photograph may appear to be the same image as the original object, but the spectral data of the photographed object may differ. Spectral data can be used to detect these differences between "real" and "fake" images.

[0039] Image sensor 206 may be a CMOS sensor or any sensor previously described, or it may be any other sensor capable of detecting wavelengths designed for use in the combined imaging and spectral sensor 200. Image sensor 206 may be connected to image processor 207, which may process image data and / or spectral data. Image processor 207 may reconstruct visual data and / or spectral data.

[0040] Sensor 200 can be small enough to be used as a smartphone camera and can provide a combination of imaging and spectral capabilities. The size of sensor 200 can be from 0.1 cubic millimeters to 3 cubic millimeters or less, allowing it to be fitted into devices with small form factor. Dispersion array 204 can have a volume of about 0.01 cubic millimeters. For example, in some embodiments, to enable the smartphone camera to use sensor 200, dispersion array 204 can be placed on top of layers of the camera lens or between layers of the camera lens. The smartphone camera may include lens 205, aperture 202, image sensor 206, and image processor 207. Depending on the design, dispersion array 204 can be placed before or after the smartphone lens or aperture. In another embodiment, sensor 200 can be integrated into the smartphone camera.

[0041] Figure 3A dispersive array 204 is depicted. The dispersive array 204 may include an array of dispersive structures 300a to 300n. A first dispersive structure 300a may allow light of a first wavelength range to pass through with reduced or no dispersiveness and reduced or no scattering, and allow light of a second wavelength range to scatter and disperse. In one embodiment, dispersive structures 300a to 300n may each be approximately 500 micrometers by 500 micrometers square, but may be of other sizes and shapes. Dispersive structures 300a to 300n may disperse light of different corresponding wavelength ranges. For example, for dispersive structures 300a to 300n, the first dispersive structure 300a may disperse light of a wavelength range of 800 nm to 820 nm, while the second dispersive structure 300b may disperse light of a wavelength range of 820 nm to 840 nm, and so on.

[0042] Each of the dispersive structures 300a to 300n can disperse light for different subgroups of the wavelength range or bandwidth spanned by the dispersion of the entire dispersive array 204. For example, the dispersive wavelength range of the dispersive array 204 can be 800 nm to 1000 nm, and if there are eight dispersive structures 300a to 300n (n = 8), each of the dispersive structures 300a to 300n can disperse light with a bandwidth of approximately 25 nm in the 800 nm to 1000 nm range. In an alternative embodiment, multiple dispersive structures 300a to 300n can exist for a given subgroup of the wavelength range to provide redundancy. For example, the dispersion array 204 may include 16 dispersion structures 300a to 300n, and the wavelength range is 800nm ​​to 1000nm. The dispersion array 204 may be designed such that each individual dispersion structure among the dispersion structures 300a to 300n has a bandwidth dispersion of approximately 25nm in the 800nm ​​to 1000nm range, but there are two dispersion structures among the dispersion structures 300a to 300n that share a common dispersion bandwidth.

[0043] Dispersion structures 300a to 300n can disperse light along a single axis. For example, as will be further described and discussed below, incident light 201 can be dispersed along an axis perpendicular to the nanostructure rows 403a to 403n created on the dispersion structures 300a to 300n. The dispersion structures 300a to 300n can be positioned to provide light scattering and dispersion at different angles relative to each other. In other words, each of the dispersion structures 300a to 300n disperses along an axis, and the dispersion axis is offset by an angle from one of the dispersion structures 300a to 300n to the other. This principle is... Figure 3As shown, each of the dispersive structures 300a to 300n has its nanostructure rows 403a to 403n formed at an angle relative to another dispersive structure among the dispersive structures 300a to 300n. For example, the first dispersive structure 300a may have a corresponding first dispersive structure angle 301a, which may be the axis along which the first dispersive structure 300a disperses light. The nth dispersive structure 300n may have a corresponding nth dispersive structure angle 301n, and so on. Therefore, each of the dispersive structures 300a to 300n may have a corresponding dispersive structure angle 301a to 301n.

[0044] In one embodiment, the angle at which light disperses between the dispersive structures 300a to 300n can be selected to provide the maximum difference in dispersive structure angles 301a to 301n from one of the dispersive structures 300a to 300n to the other. For example, in the case of n dispersive structures 300a to 300n, the angular difference in the dispersive axes between individual dispersive structures 300a to 300n can be n / 180°. For example, if n is 8 for dispersive structures 300a to 300n, then dispersive structures 300a to 300n can each be rotated approximately 22.5° from 0° to 180°, thereby providing the maximum angular difference between them. In an alternative embodiment, for redundancy, two or more of the dispersive structures 300a to 300n can share dispersive structure angles 301a to 301n. In an alternative embodiment, the dispersive structures 300a to 300n can disperse light along two axes or in a conical shape.

[0045] Figure 4 Depicting from some embodiments Figure 3 A cross-sectional view of an example dispersive array 204. Figure 4 For illustrative purposes, three dispersive structures are shown: 300a, 300b, and 300n. The principles discussed can be applied to the first dispersive structure 300a, and can also be used for... Figure 3 The dispersive array 204 and dispersive structures 300a to 300n are described. Incident light 201 can enter the first dispersive structure 300a at an angle range 401. In some embodiments, the angle range 401 can be between 0° and + / -30°, but can be other ranges. The structure of the first dispersive structure 300a and the interaction between the incident light 201 and the first dispersive structure 300a are further described below.

[0046] The first dispersion structure 300a may include a multilayer system comprising a nanostructure layer 402 and a filter layer 404, wherein the nanostructure layer 402 scatters incident light 201 into scattered light 408, and the filter layer 404 disperses the light into dispersed light 410. In one embodiment, each of the dispersion structures 300a to 300n may scatter and disperse the incident light 201 in a similar manner at dispersion structure angles 301a to 301n. The nanostructure layer 402 may be referred to as a scattering layer that can be used to scatter the incident light 201. The filter layer 404 may be referred to as a dispersion layer that can be used to disperse the light. The dispersed light 410 may include light of different wavelengths at different angles. For example, a first wavelength may be dispersed at 0° and may be referred to as a target wavelength 409, while a second wavelength may be dispersed at 10°. Dispersed light 410 may be present, and the dispersed light 410 may include a wavelength range and may be based on the optical properties of the filter layer 404. The near-field response 411 can be the response to the scattering and dispersion of the incident light 201 within the first dispersive structure 300a, and the response to the first few wavelengths of the dispersed light 410 after it leaves the first dispersive structure 300a. The far-field response 415 can be the scattering and dispersion response of the incident light 201 after the near-field response 411. Both are discussed in more detail below.

[0047] Dispersed light 410 may include light of various wavelengths for different angles. More specifically, as will be explained below, the dispersion angle of the dispersed light 410 leaving the first dispersive structure 300a depends on its wavelength. The nanostructure layer 402 may include rows of nanostructures 403a to 403n (which extend along the Z-axis and are shown as 403a, 403b, ..., 403n-1 and 403n) capable of scattering light. Incident light 201 may enter the nanostructure layer 402, and the light may interact with the nanostructure rows 403a to 403n. Some of the incident light 201 may be scattered around the nanostructure rows 403a to 403n, and a wavefront may be generated. This wavefront may be a scattering of an electric field and may define the propagation of the light field. The wavefront may have units of volt-meters and may be considered as a force. The wavefront can follow the Huygens-Fresnel principle, where each point on the wavefront can act as a source of a spherical second wavelet. The sum of the second wavelets determines the form of the subsequent wave that can produce the far-field response 415. The wavefront can have waves with varying phases and amplitudes, which can be added together to produce the far-field response 415. After the incident light 201 interacts with and is scattered by the nanostructure layer 402, the resulting light can interact with the filter layer 404, which will be described next.

[0048] Filter layer 404 may include alternating materials of a first layer 405 and a second layer 406, which will relate to Figure 5 Further discussion. The defect layer 407 can allow light within a certain wavelength range to be dispersed. For each of the dispersive structures 300a to 300n, the thickness of the defect layer 407 can vary from one of the dispersive structures 300a to 300n throughout the dispersive array 204 (see example). Figure 4 The defect layer 407 has different thicknesses among the dispersive structures 300a, 300b, and 300n. For each of the dispersive structures 300a to 300n, the varying thickness of the defect layer 407 allows light of different wavelength ranges to be filtered and dispersed at different angles. In some embodiments, the defect layer 407 may have different thicknesses for each of the dispersive structures 300a to 300n. In other embodiments, the defect layer 407 may have the same thickness for two or more of the dispersive structures 300a to 300n to provide redundancy.

[0049] The scattered light 408 may include a first set of wavelengths and a second set of wavelengths. The scattered light 408 of the first set of wavelengths can pass through the filter layer 404 with little or no dispersion within a first angular range 412 and may be referred to as specular light. The scattered light 408 of the second set of wavelengths can be scattered and dispersed into dispersed light 410 within a second angular range 413. The second angular range 413 may fall on the image sensor 206, or a subgroup of the second angular range 413 may fall on the image sensor 206.

[0050] In one embodiment, the second angular range 413 can be used to read spectral data. For example, from 0 degrees to the end of the image sensor 206, wavelengths scattered and dispersed within the second angular range 413 and reaching the image sensor 206 can be read spectrally.

[0051] In another embodiment, as described later, the spectral readout angle range 414 may be a non-overlapping angle range between the second angle range 413 and the first angle range 412. The spectral readout angle range 414 may fall on the image sensor 206, or it may extend beyond the image sensor 206. The spectral readout angle range 414 may be an angle range within which the dispersive light 410 can be spectrally read by the image sensor 206, and may be referred to as non-reflective light.

[0052] As a specific example, in one embodiment, incident light 201 can enter the nanostructure layer 402 from a range of 0° to + / -30°. Within the range of 0° to + / -30° input angle for incident light 201, the output dispersion can be 0° to + / -15° for the visible spectrum and 0° to + / -30° for the NIR spectrum; however, in other embodiments, other angles and wavelengths (from radio wavelengths to gamma wavelengths) are possible. In a spectral readout configuration only, image sensor 206 can be used to read spectral data from 0° to + / -30°. In an imaging and spectral readout configuration, image sensor 206 can be used to read image data from 0° to + / -15° and spectral data from + / -15° to + / -30°.

[0053] In one embodiment, the nanostructure layer 402 may allow the first dispersive structure 300a to provide an angular tolerance of + / -30°, meaning that any incident light 201 entering between 0° and + / -30° will provide the same output scattering angle and output dispersion angle. The output dispersion angle and angular tolerance may be due to the construction of the nanostructure layer 402. A more detailed description of the interaction between the incident light 201 and each layer is provided below. Furthermore, the materials and construction are described in more detail.

[0054] The nanostructure layer 402 can be referred to as an optical metasurface. A metasurface may include one or more planar surfaces of spatially arranged phase-shifting arrays of nanoantennas or arrays of nanopores or nanorods to scatter light. The spatially arranged phase-shifting arrays of nanoantennas or arrays of nanopores can be referred to as scatterers.

[0055] In some embodiments, the nanostructure layer 402 may comprise a dielectric-based metasurface material. The nanostructure layer 402 may comprise a dielectric or semiconductor with a high refractive index. A high refractive index can more effectively scatter light. Additionally, materials with low light absorption can allow more light to be transmitted. Example 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 trap light and re-emit light with different phases, polarizations, modes, and spectra.

[0056] The nanostructured layer 402 can bend light via a phase transition at its interface, which can be described by a generalized version of Snell's law. When light passes between two media (i.e., air and the nanostructured layer 402), it can refract at the interface. In some embodiments, the phase transition of light can vary from 0 to 2π by changing the metasurface structure of the nanostructured layer 402 as described herein. The value of the phase transition can be controlled by the size and orientation of the metasurface features. When magnetic and electric resonances overlap, the phase transition can cover the entire 2π range.

[0057] More specifically, in some embodiments, the first dispersive structure 300a allows incident light 201 to enter through the nanostructure layer 402. The incident light 201 can be manipulated through the nanostructure layer 402 via Mie scattering to provide wavelength-dependent scattering. The resulting scattered light 408 can have altered phase and amplitude. A more detailed description of the filter layer 404 is then provided.

[0058] Filter layer 404 can be a reflector. Filter layer 404 can be located on one side of nanostructure layer 402. Filter layer 404 can reflect some wavelengths while selectively allowing other wavelengths within a narrower wavelength range to pass through. Filter layer 404 can disperse scattered light 408 within a target wavelength range into dispersed light 410. Dispersed light 410 can include wavelengths dispersed at different angles (depending on wavelength) and can include a target wavelength 409. Target wavelength 409 can be a wavelength dispersed at 0° by a specific filter layer 404. The target wavelength range can be based on target wavelength 409 and can include the wavelength range of scattered light 408 dispersed by filter layer 404. The output angle range resulting from the dispersion of the target wavelength range can be a second angle range 413.

[0059] Filter layer 404 can disperse the wavelength of scattered light 408 at a specific angle in a wavelength-dependent manner to form dispersed light 410. For example, in an example embodiment of the first dispersion structure 300a, the target wavelength 409 can be 835 nm, and the target wavelength range of the dispersed light 410 can be 800 nm to 835 nm. The target wavelength 409 of 835 nm can be dispersed at 0°. The wavelength of 820 nm can be dispersed at + / - 15°, and the wavelength of 800 nm can be dispersed at + / - 30°. Filter layer 404 may include a defect layer 407, which can determine the target wavelength range of the dispersed light 410 and which specific wavelengths can be dispersed at which specific fixed angle. As will be discussed further below, the thickness of the defect layer 407 can vary for each of the dispersion structures 300a to 300n to allow the dispersion array 204 to disperse a wide range of wavelengths.

[0060] Filter layer 404 can be a distributed Bragg reflector (DBR), a dielectric mirror, a fiber Bragg grating, a semiconductor Bragg mirror, or other types of devices. Filter layer 404 can be a type of reflector formed by multiple layers of alternating materials with varying refractive indices. In one embodiment, filter layer 404 can be a DBR filter with multiple layers.

[0061] In one embodiment, filter layer 404 may include one or more alternating layers of first layer 405 and second layer 406, but more types of layers may be present, and the same principles below may apply. First layer 405 and second layer 406 may alternate on top of each other multiple times and may maintain a constant thickness or may vary in thickness. Defect layer 407 may be a layer of constant thickness or may be a layer of varying thickness including the material of first layer 405 or second layer 406 (in this example, defect layer 407 is shown as having the same material as first layer 405). In some embodiments, defect layer 407 may have an optional material.

[0062] The first layer 405 and the second layer 406 may have boundaries that can cause partial reflection of light waves and can provide interference to the incident light 201, which can block certain wavelengths. The first layer 405 and the second layer 406 may have different refractive indices that can allow certain wavelengths to pass through and change phase, which can result in wavelength-dependent angular dispersion. The refractive index of the material can vary depending on the wavelength of the light entering the material; therefore, the provided refractive index value can be an average value over a wavelength range. The first layer 405 can be a dielectric material with a refractive index between 1.6 and 2.7, and the second layer 406 can be a dielectric material with a refractive index between 1.3 and 1.6. In one embodiment, the first layer 405 can be TiO2. The refractive index of TiO2 can be about 2.45 and can be considered a high refractive index. In one embodiment, the second layer 406 can be SiO2. The refractive index of SiO2 can be about 1.45 and can be considered a low refractive index. The two refractive index values ​​can be higher or lower. The two values ​​can depend on the specific wavelength of the light passing through, and it can be helpful to consider the refractive index as an average value over the wavelength range of interest. The same principle described above can be applied to additional layers, which include defect layer 407 and layers of other materials.

[0063] The first layer 405 and the second layer 406 can have different thicknesses, which also determines which wavelengths can pass through the material. The reflectivity of the first layer 405 and the second layer 406 together can depend on the construction of the destructive interference region of the reflected light at the boundary of each layer.

[0064] For each material layer, light can have a phase delay within the material with a first refractive index n. Light can follow the law c = λf, where c is the speed of light, λ is the wavelength, and f is the frequency. When light passes through the material with the first refractive index n, the speed of light can be changed by multiplying by 1 / n. Since the frequency f can be fixed, the wavelength λ can also be changed by multiplying by 1 / n (called the effective wavelength). The effective wavelength of light can be varied within the material. Furthermore, the thickness d of the material allows light of the first wavelength to pass through, while other wavelengths can be reflected. Light of other wavelengths can be reflected from the outer and inner surfaces. Light reflected from the inner surface of the material can have a phase delay, which can interact with light reflected from the outer surface to produce interference that can be constructive or destructive. Therefore, the refractive index of the material, together with its thickness, allows for selective wavelengths to pass through the material. When the first layer 405 is stacked onto the second layer 406 in the Y direction, using the principles described herein, the reflections from both layers can filter out many wavelengths while allowing a narrow range of wavelengths to pass through. The first layer 405 and the second layer 406 together can be referred to as a stack. The layers are described in more detail below. The following principle can also be applied to additional layers in a stack, such as defect layer 407 or more layers.

[0065] In some embodiments, the first layer 405 and the second layer 406 may each have a single corresponding material and may each 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 high refractive indices. The first layer 405 and the second layer 406 may be repeatedly stacked on top of each other, which can produce Fresnel reflection at the interface 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. The Fresnel reflection together may be [(n1-n2) / (n1+n2)]. 2 .

[0066] The effective thickness of a material can be its refractive index multiplied by its thickness, and can be used to determine the material's dispersive properties. 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 achieve dispersion in the target wavelength range. Adding subsequent stacks on top of each other will allow for greater dispersive efficiency, but since the effective thickness of each stack can be the same, the target wavelength range can remain unchanged. 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 dispersive array 204 can have the same stack for each of the dispersive structures 300a to 300n, but can have defect layers 407 with varying thicknesses, which can allow for different target wavelength ranges for each of the dispersive structures 300a to 300n.

[0067] When combined to form a stack, the effective thickness of the first layer 405 and the second layer 406 can be the thickness multiplied by the refractive index, with the effective thickness being approximately half or a quarter of the target wavelength 409, where the target wavelength 409 can be dispersed at 0°. For example, for the thickness d1 of the first layer 405 and the thickness d2 of the second layer 406, the effective thickness can be n1×d1 + n2×d2, and can be adjusted to be approximately half or a quarter of the target wavelength 409. Additional stacks of the same thickness can be added to increase dispersion efficiency, but the same target wavelength 409 can still be dispersed at 0°. In other cases, if a defect layer 407 with a refractive index n1 and a thickness d3 is included, the formula can be n1×d1 + n2×d2 + n1×d3, and can be approximately half or a quarter of the target wavelength 409. The stack and the defect layer 407 can be used to determine the target wavelength range. As previously described, the target wavelength range of filter layer 404 can be the wavelength range in which dispersion can occur in each of the dispersion structures 300a to 300n, and is based on the target wavelength 409 for a particular dispersion structure.

[0068] In an optional embodiment, using the principles described above, each of the dispersive structures 300a to 300n can target a wavelength range using different materials and / or thicknesses of the stack of the first layer 405 and the second layer 406. The stack can comprise more than two layers, and each layer can have different materials and thicknesses. In embodiments with multiple stacks, each stack can also comprise different materials and thicknesses, or they can be of the same material and thickness.

[0069] An effective thickness equal to half the target wavelength 409 can lead to constructive interference and allow for highly reflective materials. An effective thickness equal to one-quarter of the target wavelength 409 can lead to destructive interference and allow for low-reflective materials. A more efficient phase shift can occur by stacking multiple alternating first layers 405 and second layers 406 on top of each other, which allows for more efficient filters. In one example, by stacking four layers of first layers 405 and second layers 406, the resolution of wavelength dispersion can be between 2 nm and 5 nm. If more stacks are added, the resolution can be reduced (higher values, such as 5 nm to 10 nm). If fewer stacks are added, the resolution can be increased (lower values, such as 1 nm to 2 nm).

[0070] In one embodiment, by stacking the first layer 405 and the second layer 406, the period of the incident light 201 can be shifted by pi, which can result in destructive interference, thereby blocking or filtering a selected wavelength while allowing other wavelengths to pass through the filter. Each layer in the filter layer 404 can have boundaries that can cause partial reflection of the light wave. When multiple layers are added together to form a stack, many reflections can be combined with constructive (half-wavelength) or destructive (quarter-wavelength) interference, and can reflect or block a selected wavelength through the filter layer 404.

[0071] For a simple example of destructive interference without the defective layer 407, if the target wavelength 409 is 800 nm, the first layer 405 and the second layer 406 can have a combined effective thickness of two quarter-wavelength filters, which can 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 shift of 400 nm), destructive interference can exist, and the target wavelength 409 can be blocked. However, in constructive interference, the target wavelength 409 can be allowed to pass through.

[0072] In another embodiment, the effective thickness of the stack including the first layer 405 and the second layer 406 may be less than half or a quarter of the thickness of the target wavelength 409, but when multiple stacks are combined, they may collectively constitute half or a quarter of the thickness of the target wavelength 409. In other embodiments, more variables may be used to determine the effective thickness of the first layer 405 and the second layer 406, including their refractive index, thickness, etc., as described herein.

[0073] As will be discussed below, the defect layer 407 can also change the target wavelength 409 that can be filtered, and by changing the effective thickness of the defect layer 407, the dispersive structure 300a to 300n can be adjusted to allow various target wavelengths 409 of the scattered light 408 to be dispersed at approximately 0° as part of the dispersed light 410.

[0074] The defect layer 407 can modify the target wavelength range to be dispersed. For each of the dispersive structures 300a to 300n, the defect layer 407 may include steps of varying thicknesses, shown as along... Figure 4 The thickness varies along the X-axis. The first step thickness allows a first target wavelength range to be dispersed in the first dispersive structure 300a, and the nth step thickness allows the nth target wavelength range to be dispersed in the nth dispersive structure 300n. For example, for each step thickness in the defect layer 407 on the dispersive structures 300a to 300n, the target wavelength range can be within 20 nm to 40 nm of each other, but other wavelength ranges can be available and can depend on the material (e.g., refractive index) and step size selection of the defect layer 407.

[0075] On the dispersive array 204, the thicknesses of the defect layer 407, the first layer 405, and the second layer 406, together, can select the entire range of wavelengths that can be dispersed across the entire range of dispersive structures 300a to 300n. For example, for the first dispersive structure 300a, the target wavelength range could be 700 nm to 725 nm; for the second dispersive structure 300b, the target wavelength range could be 725 nm to 750 nm; and so on, for the nth dispersive structure 300n, the target wavelength range could be 875 nm to 900 nm. The total range of wavelengths that can be dispersed for the dispersive array 204 can be 700 nm to 900 nm. Each of the dispersive structures 300a to 300n can disperse wavelengths beyond those in their respective target wavelength ranges, but these wavelengths can have a dispersion angle wider than the dispersion angle at which the wave may not fall on the image sensor 206. Therefore, the defect layer 407 can be designed to place a specific portion of the dispersive spectrum (target wavelength range) within a specific angular range (which may be a second angular range 413 or a spectral reading angular range 414) onto the image sensor 206, as defined by the physical size and placement of the image sensor 206.

[0076] For more details, please refer to Figure 3 Each of the dispersive structures 300a to 300n may have a defect layer 407 of a different thickness than the defect layers 407 of the other dispersive structures 300a to 300n, to allow dispersion across a wide range of wavelengths throughout the dispersive 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 previously described), then the first dispersive structure 300a may have a thickness of approximately n+x, the second dispersive structure 300b may have a thickness of n+2x, and the third dispersive structure 300c may have a thickness of n+3x, and so on.

[0077] More specifically, in some embodiments, the defect layer 407 may have various thicknesses (one thickness for each of the dispersive structures 300a to 300n) to allow light of varying target wavelength ranges to pass through. For each of the dispersive structures 300a to 300n, a target wavelength 409 may be present, which may be defined as the wavelength at which light disperses at 0°. The target wavelength 409 for each of the dispersive structures 300a to 300n may be different or may be shared by two or more of the dispersive structures 300a to 300n to provide redundancy.

[0078] As previously described, the dispersive structures 300a to 300n may not “stop” dispersing wavelengths at the ends of their respective wavelength ranges (e.g., 700 nm to 725 nm). Instead, wavelengths dispersing beyond the physical boundaries of the image sensor 206 (e.g., beyond + / - 30° in some embodiments) are not sensed and are not considered part of the “wavelength range” discussed here. That is, the dispersive wavelength range of each of the dispersive structures 300a to 300n begins at 0° with respect to the target wavelength 409 and extends to the angle defined by the outer limits of the image sensor 206.

[0079] For example, for Figure 3 The dispersive array 204 can contain n = 8 dispersive structures 300a to 300n. Furthermore, for example, the dispersive array 204 can be capable of dispersing wavelengths from 700 nm to 900 nm. According to this example, the dispersive structures in the dispersive structures 300a to 300n can disperse a target wavelength range of approximately 25 nm. The first dispersive structure 300a can disperse light from 700 nm to 725 nm (which can be the first target wavelength range). The target wavelength 409 with approximately 0° dispersion can be 725 nm. The 700 nm wavelength can be dispersed at + / - 30°, and wavelengths between 700 nm and 725 nm can be dispersed at lower angles. The defect layer 407 can have a first thickness for the first dispersive structure 300a. The second dispersive structure 300b can disperse light from 725 nm to 750 nm (which can be the second target wavelength range). The target wavelength 409 with approximately 0° dispersion can be 750 nm. The defect layer 407 can have an increased thickness (relative to the first dispersion structure 300a) for the second dispersion structure 300b, thereby dispersing different target wavelengths 409 at 0° and having a second target wavelength range (relative to the first dispersion structure 300a). For example, when the refractive index of the defect layer 407 is 1.25, the increased thickness can be 20 nm, thereby allowing a 1.25 × 20 = 25 nm shift in the target wavelength 409 and dispersion of the wavelength range. Of course, different thicknesses of the defect layer 407 can be used if the desired target wavelength 409 shift or the material refractive index is different.

[0080] In some embodiments, depending on the dispersive structure 300a to 300n, the defect layer 407 may have an increasing thickness in the manner described above to allow dispersion across the entire target wavelength range.

[0081] In some embodiments, the image sensor 206 may read imaging data from a first angular range 412 and spectral data from the dispersive light 410 in a spectral readout angular range 414. In an example embodiment, the spectral readout angular range 414 may be + / -15° to + / -30°, and the first angular range 412 for reading imaging data may be 0° to + / -15°. To compensate for the fact that some angles of the dispersive light 410 may not be used for spectral data, the overlap of target wavelengths 409 between dispersive structures 300a and 300n designed according to the principles disclosed herein can be used.

[0082] For example, the first dispersion structure 300a may have a first target wavelength range that disperses light from 700 nm to 735 nm. The target wavelength 409 with approximately 0° dispersion may be 735 nm. The 700 nm wavelength may be dispersed with + / - 30°, and the 725 nm wavelength may be dispersed with + / - 15°. Therefore, for example, if light with wavelengths from 725 nm to 735 nm falls outside the spectral readout angle range 414 on the image sensor 206 (but within the first angle range (imaging data angle) 412), the first dispersion structure 300a can provide spectral readout in the range of 700 nm to 725 nm.

[0083] 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 with approximately 0° dispersion may be 760 nm. The 725 nm wavelength may disperse with + / - 30°, and the 750 nm wavelength may disperse with + / - 15°. Therefore, when light from 750 nm to 760 nm falls outside the spectral readout angle range 414 of the image sensor 206, the second dispersion structure 300b can provide spectral readout in the 725 nm to 750 nm range. Thus, the target wavelength range of the second dispersion structure 300b can compensate for the fact that some target wavelength ranges in the target wavelength range of the first dispersion structure 300a were not measured. This overlap principle can then be repeated throughout dispersion structures 300a to 300n to allow continuous coverage of wavelengths from 700 nm to 900 nm.

[0084] The details of the target wavelength range (and associated target wavelength 409) sought for a single dispersive structure in the dispersive structures 300a to 300n can be based on the following factors: Figure 2The image sensor 206 collects image data relative to spectral data at an angle (which may be based on the physical design parameters of the image sensor 206), the number of dispersive structures 300a to 300n and any redundancy sought, the total wavelength range of the spectrum to be analyzed by the sensor 200, and various other factors that will become apparent to those skilled in the art upon reading this disclosure.

[0085] Return to reference Figure 4 The intensity of the wavelength of the dispersed light 410 can vary with the dispersion angle and can be referred to as the transmission angle intensity, as shown in [the figure]. Figure 10 This is shown in more detail below. The transmission angle intensity at a wavelength can be a function of the refractive index and thickness of the material of filter layer 404, the composition of nanostructure layer 402, the scattered light 408, and the number of stacked filter layers (first layer 405 and second layer 406). The transmission angle intensity for each wavelength can be calculated, and a distribution of the angle intensity can be generated. The dispersion of the dispersed light 410 can be calculated from the distribution. This calculation can be used to design filter layer 404, including the thickness, material, and number of stacked layers of first layer 405 and second layer 406. Further details are provided below.

[0086] Figure 5 Illustrations are provided of a process 500 for manufacturing a dispersive array 204 according to some embodiments. For example... Figure 4 As discussed herein, the first dispersive structure 300a may include a nanostructure layer 402 and a filter layer 404. Figure 5 A cross-sectional view of the dispersive structures 300a to 300n can be shown, wherein additional layers of nanostructure layer 402 or filter layer 404 can be produced or used during the manufacturing process. In this example view, the defect layer 407 may have eight steps, and a dispersive array 204 with eight dispersive structures 300a to 300n arranged side by side can be shown. The fabrication of the dispersive array 204 can be monolithic; that is, the design of all dispersive structures 300a to 300n can be completed together.

[0087] The layers of substrate 501 can be used as a substrate for adding additional layers to the dispersive structures 300a to 300n. Substrate 501 can be glass, silicon, or other optically transparent materials within the wavelength range of interest. Substrate 501 can be used in the manufacturing process and can be disposed of after manufacturing. The first layer 405 and the second layer 406 can be deposited alternately on each other to form the first filter layer 502 as shown in structure 510. In one embodiment, the first layer 405 and the second layer 406 have two different materials; however, additional layers of other materials can be used. The first layer 405 can have a first thickness d1, and the second layer 406 can have a second thickness d2. The alternating first layer 405 and the second layer 406 can have the same thicknesses d1 and d2, or their thicknesses can vary. The first filter layer 502 can allow filtering of selected wavelengths to pass through.

[0088] A defect layer 407 can be fabricated on top of the first filter layer 502. The defect layer 407 may include a stepped pattern of varying thickness. The varying thickness of the defect layer 407 can allow for dispersion of light over a varying wavelength range. The defect layer 407 may be made of a defect preparation layer 504 and one or more defect lithography layers 503. The defect lithography layers 503 may be one or more photomasks and may be polymer films. The defect preparation layer 504 may be the same material as one of the first layer 405 and the second layer 406, or it may be a different material. The defect preparation layer 504 can be deposited on top of the first filter layer 502. The defect lithography layer 503 can be deposited on top of the defect preparation layer 504, and the defect lithography layer 503 can form a photolithography structure 511. A photomask and etching (in one or more repeated processes described in more detail below) can be applied to the defect photomask layer 503, which can change the structure of the defect preparation layer 504 and form a final structure 512 including the defect layer 407, which will be described in more detail below.

[0089] An additional first layer 405 and a second layer 406 can be alternately deposited on top of 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 can constitute... Figure 4 Filter layer 404. Return to reference. Figure 5A cap stack 506 can be deposited on the second filter layer 505 and leveled to form structure 513. The cap stack 506 may have a photomask 507 temporarily deposited thereon to allow photolithography to form nanostructure rows 403a to 403n by etching, thereby forming structure 514. When etching nanostructure rows 403a to 403n for each of the dispersive structures 300a to 300n, the photomask 507 can be removed to form structure 515, which may be the dispersive structures 300a to 300n.

[0090] In one embodiment, the first layer 405 may be titanium dioxide (TiO2) and may be deposited via a sputtering method, but any other technique for depositing material on the substrate 501 may be used.

[0091] The second layer 406 can be silicon dioxide (SiO2). The second layer 406 can be deposited via plasma-enhanced chemical vapor deposition (PECVD), but any other technique can be used for deposition.

[0092] In one embodiment, the first layer 405 may be 83 nm thick, and the second layer 406 may be 135 nm thick to target a wavelength of 800 nm, with the first layer 405 comprising TiO2 and the second layer 406 comprising SiO2. Before the defect layer 407, for a total of eight layers (alternating between the four layers of the first layer 405 and the four layers of the second layer 406), four stacks of the first layer 405 and the second layer 406 may exist, stacked on top of each other. Fewer or more stacks may exist. After the defect layer 407, another four stacks of the first layer 405 and the second layer 406 may exist. To target other wavelengths, as discussed herein, other thicknesses may be used. Fewer or more stacks may exist.

[0093] As previously described, the defect layer 407 can be formed by depositing a thicker layer (which may be the defect preparation layer 504) of either the first layer 405 or the second layer 406. Grayscale photolithography can be applied to form the defect layer 407. Ultraviolet (UV) exposure can be applied to the defect lithography layer 503. The defect lithography layer 503 can cover the entire surface of the defect preparation layer 504. Figure 5In the example shown, UV radiation can be applied in the X direction within a range 508, and the total dose of UV exposure can vary within the range 508. UV radiation can also be applied in the Z direction. Variable dose power or variable time dose UV exposure can be applied, which will affect the durability of the defective lithography layer 503 under etching along the X direction, and this can then result in a defective layer 407 of variable thickness. For example, the variable dose power level for eight zones can have power levels of x, 7 / 8x, 6 / 8x, ..., down to 1 / 8x. The variable time dose of UV exposure can have the same power level x, and for each zone can have a time t, 7 / 8t, 6 / 8t, ..., down to 1 / 8t. After applying UV exposure, etching can be performed, which can produce the defective layer 407. The etching can be dry etching or wet etching.

[0094] In an alternative method, a stepped structure of the defect layer 407 is generated from the defect preparation layer 504 using repeated etchant mask lithography. Specifically, in each lithography cycle, an etchant mask covering one less step than the previous etchant mask stage is used, and the device is etched down one "step" in height. By repeating this process, a stepped structure is generated.

[0095] Figure 6 A top view of the example dispersion structure 300a is depicted, and specific details are shown. Figure 4A top view of the nanostructure layer 402. Nanostructure rows 403a to 403n are distributed along the X-axis. Nanostructure rows 403a to 403n may include multiple nanopores or nanoantennas (shown here as nanopores) extending along the Z-axis. Nanostructure rows 403a to 403n may be placed adjacent to each other along the X-axis and extend parallel to each other along the Z-axis. Nanostructure rows 403a to 403n may be patterned, and the pattern may be a semi-random pattern. The distance between two adjacent nanostructure rows 403a to 403n may be randomly distributed between the minimum and maximum permissible distances of each adjacent row along the X-axis. In one embodiment, nanostructure rows 403a to 403n may have a maximum distance between adjacent rows of half the length of the longest wavelength in the target wavelength range of the first dispersive structure 300a; this may be the target wavelength 409. A semi-random pattern may be achieved using inverse transform sampling for uniform distribution. Semi-random patterning allows for low or no spatial correlation between adjacent nanostructure rows 403a to 403n. In the case of low or no spatial correlation, a constant output scattering range of light can be allowed within the angular range (incident angle range) 401 within a first angular range 412 and a second angular range 413. Since there is no row pattern, and therefore the light is not pattern-dependent, the random distribution of nanostructure rows 403a to 403n along the X-axis allows the nanostructure layer 402 to be independent of… Figure 4 The operation is based on the polarization of the incident light 201.

[0096] In one embodiment, a nanostructure row (such as 403a) may include nanopores 601a to 601n. Each of the nanostructure rows 403a to 403n may include a copy of the group of nanopores 601a to 601n. The nanopores 601a to 601n may be similar or different in terms of radius, thickness, and distance between adjacent nanopores within the target nanostructure row (such as 403a). In one embodiment, the nanopores 601a to 601n may have a radius of 140 nm and a depth of 750 nm, but they may be larger or smaller.

[0097] In one embodiment, nanopores 601a to 601n can be spaced approximately equally apart from each other. Nanopores 601a to 601n can be placed close together to allow light to pass through in the Z direction with little or no scattering. To allow light to pass through in the Z direction with little or no scattering, the following conditions must be met:

[0098] λ≥n·d.

[0099] Wherein, wavelength λ can be the wavelength of interest, n can be the refractive index of nanopores 601a to 601n, and d can be the distance between adjacent nanopores 601a and 601b. For example, the distance between adjacent nanopores 601a to 601n in the first nanostructure row 403a can be 10 nm to 200 nm, and the refractive index can be about 1.5, which allows for the scattering of both visible and NIR light. Scatter-free or low-scattering conditions can be used for the design of one-dimensional structures as described below.

[0100] One-dimensional structures can be patterned in one dimension, such as the distribution of nanostructure rows 403a to 403n along the X-axis. The pattern can be a repetition or random distribution of nanostructure rows 403a to 403n, and will be discussed in more detail later. One-dimensional structures can maintain consistency in a second dimension, such as maintaining the same number or placement of nanopores 601a to 601n in the Z-direction between nanostructure rows 403a to 403n; for each nanostructure row 403a to 403n, the same number or placement of nanopores 601a to 601n can be repeated.

[0101] Two-dimensional structures can be patterned in both the first and second dimensions. For example, nanostructure rows 403a to 403n can have a pattern along the X-axis. As previously described, the pattern can be a random distribution of nanostructure rows 403a to 403n along the X-axis between minimum and maximum distances. Additionally, the first nanostructure row 403a can be patterned with nanopores 601a to 601n in the Z-direction within the row. For example, the first nanostructure row 403a can have patterned nanopores 601a to 601n, the patterns having different diameters, shapes, thicknesses, and spacings between each nanopore 601a to 601n.

[0102] As previously described, light can travel in one direction (it can follow) Figure 6 Light scatters along the X-axis (perpendicular to nanostructure rows 403a to 403n) through the first dispersive structure 300a, but can be essentially not scattered along the direction parallel to nanostructure rows 403a to 403n (shown as the Z-axis direction). This uniaxial scattering is likely due to the proximity of nanopores 601a to 601n in the Z-direction, as the distance between two adjacent nanopores in nanopores 601a to 601n is smaller than the wavelength of the incident light 201, thus allowing light to pass through essentially with little or no scattering. Then, because the nanostructure rows 403a to 403n are spaced far enough apart (according to a semi-random distribution), scattering can occur along the X-axis, thus preventing certain wavelengths of light from passing through without scattering.

[0103] More specifically, the radius r of the first nanopore 601a can impart a phase shift θ in the incident light 201, which can lead to... Figure 4 The near-field response 411 shown and previously described. The near-field response 411 of a single nanopore (such as the first nanopore 601a) can be referred to as... Figure 4 The near-field response 411 may include targeting Figure 6 The sum of the near-field responses 411 of all nanostructure rows 403a to 403n and nanopores 601a to 601n.

[0104] A larger radius r of the first nanopore 601a allows for more scattering, while a smaller radius allows for less scattering, which may be due to Mie scattering. Light scattered by a single first nanopore 601a can be scattered in a conical shape. In one embodiment, the radius r can be about 140 nm to 150 nm; however, depending on the target wavelength 409, the radius can be larger or smaller. The radius r of the first nanopore 601a can be half or less of the target wavelength 409 in the target wavelength range of the dispersive structure 300a. As will be discussed below, when nanopores 601a to 601n form the first nanostructure row 403a, the proximity of nanopores 601a to 601n to each other in the Z direction allows light to pass through and is substantially non-dispersed in the Z direction.

[0105] When nanostructures are distributed in rows 403a to 403n in the X direction Figure 4 The scattering of incident light 201 can be largely confined to the X-direction. The nanostructure rows 403a to 403n can be designed to scatter light of selected wavelength and angle due to Mie scattering by selecting the radius r of the nanopores 601a to 601n and distributing the nanostructure rows 403a to 403n semi-randomly. The average distance between all nanostructure rows 403a to 403n can determine whether light is scattered and at what wavelength.

[0106] In one embodiment, the row distribution can depend on the density of the nanostructure rows 403a to 403n. The density of the nanostructure rows 403a to 403n can be the surface area of ​​the nanopores 601a to 601n divided by the total surface area. For a one-dimensional construction, the density can be higher when the nanostructure rows 403a to 403n are spaced closer together, and lower when they are spaced further apart. The spacing between the nanostructure rows 403a to 403n can be referred to as the row density. The row density can be the count of nanostructure rows 403a to 403n per unit length on the first dispersive structure 300a, and can be used to determine the density for a one-dimensional construction. By changing the row density, the efficiency of the first dispersive structure 300a can be changed.

[0107] If sensor 200 reads both image data and spectral data, efficiency can be the ratio of the intensity of the dispersed light 410 in the second angular range 413 to the intensity of the incident light 201. If sensor 200 reads only spectral data, efficiency can be the ratio of the intensity of the dispersed light 410 in the spectral reading angle range 414 to the intensity of the incident light 201. Intensity can be measured in lux. Efficiency can also be described as the ratio of the intensity of the non-mirror front-scattered light, which is dispersively and spectrally read by image sensor 206, to the intensity of the incident light 201. Efficiency can be used to determine the density of nanostructure rows 403a to 403n. In contrast to non-mirror front-scattered light, mirror front-scattered light can contain zero-order transmitted light, which can be scattered light 408. Non-mirror front-scattered light can contain higher-order or non-zero-order transmitted light, and can be light dispersed at a non-zero angle. Image sensor 206 can read the spectrum of non-mirror light. Higher efficiency can result in a higher probability of scattering the incident light 201. As will be described in more detail below, the scattering of incident light 201 can depend on the target wavelength 409, aperture density, and row density.

[0108] As described below, in order to determine the efficiency of the first dispersive structure 300a for nanostructure rows 403a to 403n of a given density, the near-field response analysis of nanopores 601a to 601n can be performed. Near-field response 411 The radius of the nanopores 601a to 601n used can be considered. The collective near-field response 411 of the nanopores 601a to 601n can be used to determine the row density of the nanostructure rows 403a to 403n of the first dispersive structure 300a. The first nanopore 601a can have a radius of... and The nanopores 601a to 601n can be similar, which can be followed by the following equation:

[0109]

[0110] Here, θ can be the phase shift of the incident light 201, i is the imaginary unit, and R is the radius of the first nanopore 601a from which the light can no longer be scattered, and can be approximately half the width of the wavelength to be scattered. By determining the radii of nanopores 601a to 601n, the density of the first dispersive structure 300a can be determined.

[0111] At higher row densities of nanostructure rows 403a to 403n, the amount of scattered incident light 201 can be reduced due to subwavelength conditions. Subwavelength conditions can occur when the average distance d between adjacent nanostructure rows 403a to 403n decreases from the maximum subwavelength value of half the target wavelength 409 to 0 nm, as will be further described below.

[0112] The row density, including the distribution and average distance between adjacent nanostructure rows 403a to 403n, can be determined by the target wavelength 409 of the incident light 201, which can be scattered. The maximum distance between adjacent nanostructure rows 403a to 403n can be closer to each other than the subwavelength of the target wavelength 409 of the incident light 201. For example, for an 800 nm wavelength, the subwavelength can be 400 nm, and the maximum distance between adjacent nanostructure rows 403a to 403n can be 400 nm. If, for an 800 nm wavelength, adjacent nanostructure rows 403a to 403n are within 400 nm of each other, then the 800 nm wavelength can be scattered. If the distance between two adjacent nanostructure rows 403a to 403n is closer to the maximum distance of 400 nm, more scattering can exist. If the distance between two adjacent random nanostructure rows 403a to 403n is closer to 0 nm, less scattering can exist. Therefore, when designing the placement of nanostructure rows 403a to 403n, the row density can affect the scattering efficiency. Furthermore, if a pattern exists for placing the nanostructure rows 403a to 403n, light scattering can depend on this pattern. For example, if the nanostructure rows 403a to 403n are uniformly spaced or spaced by repeatable patterns, scattering across the target wavelength range can occur at a fixed angle for each wavelength and may not occur within the first angle range 412 or the second angle range 413. Therefore, the placement of the nanostructure rows 403a to 403n can be a semi-random uniform distribution using inverse transform sampling to produce a random distribution between minimum and maximum distances.

[0113] In some embodiments, the distribution of nanostructure rows 403a to 403n can be expressed by a probability density function. To determine this, the probability density function can be used to provide the boundaries for the random placement of each row.

[0114] In some embodiments, the Fourier transform of the probability distribution of nanostructure rows 403a to 403n can be written as: The Fourier transform of the probability density function can be used to determine how rows 403a to 403n of the nanostructure are randomly or semi-randomly distributed. The Fourier transform can be a characteristic function of the distribution of rows 403a to 403n of the nanostructure. It can be used to construct a random distribution of nanostructure rows 403a to 403n, allowing the distribution of nanostructure rows 403a to 403n to be as independent as possible from the scattered light 408, which can be represented as scattered light.

[0115] Using a Fourier transform to construct the random distribution, a semi-uniform random distribution of nanostructure rows 403a to 403n can be generated to allow for no spatial correlation between adjacent nanostructure rows 403a to 403n. The lack of spatial correlation among adjacent nanostructure rows 403a to 403n allows for a variety of angles in the angular range (incident angle range) 401, thereby allowing for a constant output scattering range of light within the first angular range 412 and the second angular range 413.

[0116] Mirror surface of transmitted light Positional information of the scattered light 408, which can be used to construct an incident image, can be provided. The positional information of the scattered light 408 and the dispersive light 410 allows for simultaneous imaging and spectral analysis of light from the first dispersive structure 300a. In some embodiments, optimizing the scattering of high-angle light for angle-dependent spectra can be beneficial.

[0117] Figure 7 The design analysis of the one-dimensional construction of the first dispersive structure 300a is described. Figure 7 An example efficiency-density relationship is shown for a first dispersive structure 300a with a target wavelength range of 700 nm to 725 nm. In some embodiments, Figure 4 The efficiency of the near-field response 411 and Figure 6 There is a relationship between the different total densities of nanostructure rows 403a to 403n. The efficiency relationship can be used to determine the row density of nanostructure rows 403a to 403n.

[0118] Figure 8 A top view of an example nanostructure layer 402 is depicted. The nanostructure layer 402 may include a nanoantenna 801 and can be used as... Figure 6 Option embodiments of nanopores 601a to 601n are provided. The nanoantenna 801 may have a subwavelength thickness. In one embodiment, a subwavelength of half the target wavelength 409 may be used. The nanoantenna 801 may be made of a plasma material or a dielectric material. The nanoantenna 801 may be able to manipulate light via spatially arranged meta-atoms. The meta-atom may be an atomic portion of a structured pattern (such as a hole, antenna, or other shape). The nanoantenna 801 may be an antenna with a size of approximately 10 nm to 1000 nm.

[0119] Plasmonic materials can include metals, transparent conductive oxides, transition metal nitrides, or 2D materials. Plasmonic nanoantennas can interact with light through plasmonic resonance. During the interaction, electrons in the plasmonic nanoantenna can be deflected from their steady-state positions due to an external electric field; this can be termed polarization. Electron polarization can generate an internal field that restores the electrons to their steady state. Under the influence of the external electric field, electron oscillations can occur with a phase shift of pi within the spectral width of the plasmonic resonance. Noble metals (such as gold and silver) can be used as building materials for plasmonic structures. Further modifications can be utilized, such as generating V-shaped nanoantennas to support two resonant modes and incorporating a metallic ground plane separated from the nanoantenna array by thin dielectric spacers. By adding thin dielectric spacers, incident light can induce antiparallel currents on the nanoantenna 801 and the ground plane, which can generate gap resonance and provide a phase shift from 0 to 2pi.

[0120] Plasma nanoantennas can be fabricated using focused ion beam milling. Thin metal layers can be milled using a focused ion beam to create the plasma nanoantenna structure. Nanoantenna 801 can also be a dielectric nanoantenna or a dielectric nanopore. Dielectric nanoantennas or nanopores can manipulate light through Mie scattering. Dielectric nanoantennas can also be fabricated using electron beam lithography and e-beam evaporation.

[0121] Figure 9 Depicting the target Figure 2 Example of a graph showing the dispersive efficiency of light at various wavelengths in an embodiment of the dispersive array 204. The efficiency response for the first band can be response 901a, which can correspond to the first dispersive structure 300a. Subsequent responses 901b to 901n can be associated with subsequent dispersive structures 300b to 300n. Figure 9 It can be used to construct and verify Figure 6 The efficiency of the dispersive structures 300a to 300n and their corresponding nanostructures 403a to 403n. Furthermore, this efficiency can be used to calibrate the dispersive structures 300a to 300n. This efficiency can also be used for spectroscopic purposes. When by Figure 2 When the sensor 200 reads an image, it can refer to, for example... Figure 9 The efficiency curve is used to explain the spectral response.

[0122] In this example, the dispersion array 204 may include n = 8 dispersion structures 300a to 300n that can cumulatively provide dispersion efficiency for light with wavelengths of approximately 700 nm to 900 nm. Figure 3 The dispersive structures 300a to 300n can have dispersive efficiency responses corresponding to 901a to 901n, respectively.

[0123] Figure 10An example embodiment of the dispersion structure (such as 300a to 300n) is depicted. Figure 4 The angular intensity dispersion curves of the 410 dispersed light at various dispersion output angles θ. When designing... Figure 4 The parameters of the nanostructure layer 402 (e.g., in designing a specific dispersive structure such as 300a) and also used in designing the image sensor 206 can be obtained using the wavelength-dependent dispersion angle shown. In one example, Figure 10 The angular intensity dispersion of a first dispersive structure 300a can be shown when the target wavelength range of the dispersive light 410 is between 800 nm and 835 nm. A wavelength of 835 nm can pass through an example first dispersive structure 300a with 0° dispersion. A dispersion output angle θ of approximately + / - 30° can correspond to a wavelength range of 800 nm to 835 nm, which can be a second angle range 413. In one embodiment, the second angle range 413 can be used for spectral analysis. In another embodiment, the first angle range 412 can be a wavelength used for imaging rather than for spectral analysis. The first angle range 412 can be + / - 15°. The spectral readout angle range 414 can be + / - 15° to + / - 30°.

[0124] For other dispersive structures (such as 300b to 300n), there can be dispersive light 410 with different target wavelength ranges, so different wavelengths can be dispersed at a specific angle (e.g., + / -30°).

[0125] From a design perspective, the dispersion angle of each wavelength can be fitted to an exponentially broadened Lorentzian distribution, thus producing a distribution similar to... Figure 10 The curve in the graph.

[0126] The peak position with respect to wavelength can be extracted from the fitting of the exponentially broadened Lorentz distribution. The peak position can then be fitted to the following equation to extract the target wavelength 409 of the dispersive light 410 and the refractive index n* of the filter layer 404. For the calculations below, the full width at half maximum (FWHM) of the fitted dispersion angle and wavelength can be considered to determine the properties of the first dispersive structure 300a. The dispersion angle λ(θ) of the dispersive light 410 can depend on the target wavelength 409(λ0) of the dispersive light 410 and the refractive index n* of the filter layer 404:

[0127]

[0128] In some embodiments, the peak position can be used to determine the target wavelength 409 of the dispersive light 410, which can be used to generate a dispersive array 204 having dispersive structures 300a to 300n.

[0129] Figure 11 Depicting the incident light 201 passing through Figure 2 The aperture 202 and dispersive array 204 (and possibly lens 205) then enter from the center of the image sensor 206 and define the image from the side view through the central axis of the image sensor 206. Figure 2 The image sensor 206, aperture 202, and dispersive array 204 are located at a specific height (away from the page) from the image sensor 206. The image sensor 206 includes an inner region 208 and an outer region 209, each of which includes a corresponding plurality of pixels. The inner region 208 includes a first group of pixels within a first angular range 412 of the axis of the incident light 201 traveling from the dispersive array 204 and lens 205, while the outer region 209 includes a second group of pixels within a larger second angular range 413 of the axis of the incident light 201 traveling from the dispersive array 204 and lens 205, the second angular range 413 not yet surrounded by the inner region 208. Figure 12 As shown graphically, the inner region 208 and outer region 209 of the image sensor 206 can be viewed from... Figure 3 The dispersive structure from 300a to 300n is used to read imaging and spectral data.

[0130] More specifically, in some embodiments, the inner region 208 can be used to image the scattered light 408, and the outer region 209 can be used to read the spectrum of the scattered light 410. In some embodiments, the inner region 208 can be a group of pixels logically grouped into a circle, and the outer region 209 can be a group 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 can be used together to read only spectral data.

[0131] More specifically, the review filter layer 404 can allow light of certain wavelengths within a first angular range 412 (e.g., scattered light 408) and a selected set of dispersive light 410 of different wavelengths within a second angular range 413 to pass through without dispersion, and the precise dispersion angle is based on the wavelength of the light. Therefore, since light with wavelength-dependent angular dispersion reaches these pixels, spectral readout can be performed using the sensor pixels in the outer region 209.

[0132] Since the inner region 208 receives light that has undergone reduced scattering and contains only a portion of the dispersed light 410, the inner region 208 can read imaging data from all the received light falling within it.

[0133] For example, if the first angle range 412 is 0° to + / -15° and the second angle range 413 is 0° to + / -30°, then the inner region 208 can image visible light in the range of 0° to + / -15°, and the outer region 209 can read dispersive NIR light in the range of + / -15° to + / -30°.

[0134] Figure 12 A composite image 1201 is depicted that can be illuminated by incident light 201. In one embodiment, incident light 201 may include visible light or NIR broadband light.

[0135] A composite image 1201 with a center can be seen, and the composite image 1201 has stripes radiating radially from the center towards the edges. For illustrative purposes, the composite image 1201 may be presented in false colors. The composite image 1201 may be a false color representation of an image captured by a monochromatic sensor, and the color may represent the intensity or brightness of the image. Due to both light scattering (scattered light 408) and light dispersion (dispersed light 410), the composite image 1201 may appear blurry. Stripes such as 1204 may be the result of light scattering along a single axis from a single dispersion structure (optical dispersion mechanism) among the dispersion structures (optical dispersion mechanisms) 300a to 300n.

[0136] Reference Figure 3 Each of the dispersive structures 300a to 300n can scatter and disperse light in one dimension. For example, the dispersive structures 300a to 300n can scatter and disperse light along an axis perpendicular to the axis of the dispersive structures 300a to 300n, which includes the nanostructure rows 403a to 403n. Since each of the dispersive structures 300a to 300n is at a different angle from the other dispersive structures 300a to 300n, each of the dispersive structures 300a to 300n produces its own unique fringe in a defined orientation, which corresponds to the placement of the dispersive structures 300a to 300n within the dispersive array 204. Figure 12 It is possible to depict n = 8 dispersion structures 300a to 300n, wherein the fringes of scattered and dispersed light shown in the composite image 1201 are all spaced 22.5° apart from each other, and each fringe corresponds to a dispersion structure angle 301a to 301n.

[0137] Each of the dispersive structures 300a to 300n can be configured to disperse incident light 201 within a defined set of target wavelengths (as discussed above, in part based on their respective target wavelengths 409 and the dimensions of their defective layers 407). As previously discussed, each of the dispersive structures 300a to 300n can produce a unique linear fringe of dispersive spectral light, such as fringe 1204 for the first dispersive structure 300a. Furthermore, as discussed above, due to the physical connection between the dispersive array 204 and the image sensor 206, each fringe can occur at a unique known location and orientation. Finally, within each fringe, each specific wavelength will be dispersed at a known angle corresponding to a known distance from the center of the image. Therefore, light of each wavelength received within the entire target wavelength range of the dispersive array 204 can fall on a known region on the image sensor 206, and thus on known pixels. Based on this information, a precise determination of the spectral composition and intensity of a given light signal can be made based on the signals received from these pixels.

[0138] After the image sensor 206 reads the composite image 1201, image 1202 and spectral data 1203 can be extracted. In one embodiment, image 1202 may be a visible image, and spectral data 1203 may be an NIR spectrum. Post-processing algorithms can be applied to extract image 1202 and spectral data 1203.

[0139] To reconstruct the image, post-image processing can be used to remove artifacts caused by scattering. In some embodiments, this may involve applying a deblurring algorithm based on the calibration of the dispersive structures 300a to 300n. In some embodiments, this may involve measuring the point spread function (PSF) by measuring the transmission angle intensity through each dispersive structure 300a to 300n when illuminated by collimated visible light (400nm to 650nm). The measured PSF can be deconvolved from the original image using the Richardson-Lucy algorithm. Ten iterations can be used to provide a balance between deblurring and avoiding ringing artifacts.

[0140] To reconstruct the measured spectrum, in some embodiments, the following steps can be utilized. The spectrum can be extracted from the spectral region of the original data by fitting an ideal model of the wavelength-related scattering fringes of the dispersive structures 300a to 300n. When incident light 201 illuminates the dispersive structures 300a to 300n, firstly, the incident light 201 can be scattered to different angles depending on the orientation of the first dispersive structure 300a and the initial angle of the light. Secondly, the light can be filtered and dispersed at a set of angles according to the spectral content of the light (e.g., wavelength).

[0141] Therefore, it can be relative to the incident light angle θ on the detector. x θ y and the scattering intensity distribution g(θ) with respect to position x, y x θ y Modeling is performed using the dispersion structure 300a to 300n. An ideal dispersion structure 301a to 301n can scatter incident light equally to all pixels along its dispersion structure angles. Therefore, g can be defined as:

[0142]

[0143] Where f can be the focal length of the focusing lens, and θ can be the angle of the axial orientation of the dispersive structure from 300a to 300n. For a given image, the total scattering intensity distribution can be written as:

[0144] g′(x, y)=∫∫α(θ) x θ y )g(θ x θ y ,x,y)dθ x dθ y .

[0145] Where α(θ) x θ y ) is the intensity distribution of the image used as an input parameter in the model.

[0146] Next, the filtering effect at different angles with spectral intensity I(λ) can be described. For the first dispersive structure 300a, only the target wavelength range of the dispersive light 410 (which can be referred to as λ for a given angle θ) is considered. R (θ) can be transmitted at a given angle θ. Therefore, we can define the spectral filtering function at pixel positions x,y as:

[0147] S(x,y)=∫I(λ)·δ(λ) R (θ eq (x, y))-λdλ=I(λ R (θ eq (x, y)).

[0148] For optical systems, θ eq (x, y) can be the angle corresponding to the pixel positions x and y, θ eq (x, y) can be written as:

[0149]

[0150] Finally, the full fringe pattern of the dispersive structure from 300a to 300n can be calculated by multiplying the spectral filter by random scattering to obtain the final spectral fringe pattern:

[0151] SP(x,y)=g′(x,y)·S(x,y).

[0152] The same calculations can be repeated for each of the n dispersive structures 300a to 300n, and then the intensity patterns can be summed together to obtain the final spectral stripe pattern from the model.

[0153] To calculate the spectrum from the measured stripe pattern, in some embodiments, a spectrum with, for example, 10... -6 The least squares fitting method (LSQR) with tolerance fits the obtained model to the original data.

[0154] As mentioned above, ideal dispersive structures 300a to 300n are considered to have angle-independent scattering and transmission efficiencies. However, in practice, since scattering can be completely random, slight intensity variations relative to angle can be observed. Additionally, due to Fresnel reflection, light at higher angles may transmit through the filter less efficiently than light at lower angles. Furthermore, the wavelength-dependent transitions from one dispersive structure to another in 300a to 300n can introduce additional errors. To correct for these errors, a wavelength-dependent calibration term is multiplied across the spectrum:

[0155] I′(λ)=c′(λ)I(λ).

[0156] Where I′ is the calibrated spectral intensity, and c′ is the calibration factor. To calculate c′, the spectrum measured using a high-resolution commercial spectrometer can be divided by the spectrum I(λ) measured by dispersive structures 300a to 300n for incident unfiltered light. This factor can then be used to calculate the spectrum using dispersive structures 300a to 300n, which shows good agreement with measurements from the reference spectrometer.

[0157] Since the calibration takes into account the non-constant scattering of the dispersive structure from 300a to 300n, it can vary depending on the angle of incidence of the light, and therefore on the incident image. Thus, a separate calibration matrix c′(λ) for each angle of incidence can be measured and applied to each image used. However, in the more general setting where the images are not known a priori, an arbitrary calibration factor for any image can be calculated using the linearity of the system, as shown in the following formula:

[0158] I single-point (λ)=f(g(θ x θy ,x,y)),

[0159] I′(λ)=c(θ x θ y ,λ)I single-point (λ)=c(θ x θ y ,λ)f(g(θ) x θ y ,x,y)),

[0160]

[0161] Finally, using the definition of the calibration factor, the total calibration factor c′ can be calculated:

[0162]

[0163] Therefore, if pre-calibration is performed to measure c(θ) x θ y If λ), then the total calibration factor c′(λ) can be calculated for any arbitrary incident image using the dispersive structures 300a to 300n. Once fully calibrated (such as after factory production), the sensor 200 containing the dispersive array 204 with the dispersive structures 300a to 300n can be used for in-situ spectral measurements.

[0164] Figure 13 The fabrication process 1300 for the dispersive array 204 is described. More specifically, Figure 13 Describing the formation in Figure 5 The process of structures 510 to 515 is illustrated graphically. Manufacturing process 1300 can be a single-wafer process.

[0165] Reference Figure 4 and Figure 5 The first process 1301 may include depositing a first layer 405 on top of 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 include, but are not limited to, sol-gel deposition, pulsed laser deposition, molecular beam epitaxy, and atomic layer deposition.

[0166] The second process 1302 may include depositing a second layer 406 onto 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 and deposition techniques may also be used.

[0167] The third process 1303 may include depositing alternating first layers 405 and second layers 406 after the second process 1302. That is, the first process 1301 and the second process 1302 may be repeated multiple times, one after the other, to construct an alternating series of first layers 405 and second layers 406, thereby producing a desired number of first layers 405 and second layers 406. (Previous information regarding...) Figure 5 The materials and design of the first layer 405 and the second layer 406 are described.

[0168] The fourth process 1304 can deposit a defect preparation layer 504. In one embodiment, the defect preparation layer 504 can be SiO2 and can be deposited via PECVD, but other materials and deposition techniques can also be used. In one embodiment, the defect preparation layer 504 can be a thicker SiO2 layer. The thickness of the defect preparation layer 504 can be determined by the desired thickness of the defect layer 407 after processing the defect preparation layer 504.

[0169] The fifth process 1305 may include depositing one or more defect photolithography layers 503 onto the defect preparation layer 504 after the fourth process 1304. The defect photolithography layer 503 may be a photoresist and may be a polymer.

[0170] The sixth process 1306 can apply UV exposure to the defect photolithography layer 503 and can also penetrate to the defect preparation layer 504. This is possible... Figure 5 UV radiation is applied within a range 508, and the total dose of UV exposure can vary within this range. Variable dose power or variable time dose UV exposure can be applied, which can form a variable thickness defect layer 407. For example, the variable dose power level for eight zones can have power levels of x, 7 / 8x, 6 / 8x, ..., down to 1 / 8x. The variable time dose of UV exposure can have the same power level x, and for each zone, it can have a time t, 7 / 8t, 6 / 8t, ..., down to 1 / 8t. The fifth process 1305 and the sixth process 1306 together can be referred to as grayscale lithography, but other techniques can be used.

[0171] The seventh process 1307 may include etching a defect photolithography layer 503 and a defect preparation layer 504. In one embodiment, dry etching may be used, in which a focused electron beam may bombard the defect photolithography layer 503 and the defect preparation layer 504 to form a defect layer 407. Other etching techniques may be used. The defect layer 407 may have a variable thickness (after the subsequent process steps described above) and may allow for the dispersion of light at variable wavelengths due to its varying thickness. In one embodiment, the defect layer 407 may have eight thickness steps, and the eight layers of different thicknesses may allow for the dispersion of wavelengths in the 2 nm to 5 nm sub-band.

[0172] In optional embodiments, such as regarding Figure 5 The discussion suggests that multiple rounds of etchant masking and etching can be performed to generate defect layer 407 from defect preparation layer 504.

[0173] The eighth process 1308 may include depositing a first layer 405 onto the defect layer 407 using the same technique as described in the first process 1301. The first layer 405 may include the same material as in the first process 1301, and its thickness may be the same or may vary.

[0174] The ninth process 1309 may include depositing the second layer 406 using the same technique as described in the second process 1302. The second layer 406 may include the same material as in the second process 1302, and its thickness may be the same or may vary.

[0175] The tenth process 1310 may include alternating deposition of the first layer 405 and the second layer 406 of the eighth process 1308 and the ninth process 1309 once or more as desired (i.e., to produce a desired number of repeating layers including the first layer 405 and the second layer 406).

[0176] The eleventh process 1311 may include depositing a cap stack 506. In one embodiment, the cap stack 506 may include the material of the first layer 405 and may be deposited using the first process 1301 over a longer period of time. The cap stack 506 may be TiO2 and may be deposited via a sputtering method. The cap stack 506 may be significantly thicker than the first layer 405 and the second layer 406 and may be flush with the initial layer / substrate to allow for the formation of nanostructures therein.

[0177] The twelfth process 1312 may include depositing a photomask 507 onto a cap stack 506. The photomask 507 may be a photoresist and may be a polymer.

[0178] The thirteenth process 1313 can apply radiation to the photomask 507 and can also penetrate to the cap stack 506. The radiation can be electron beam lithography, UV exposure, or other forms of radiation. The radiation can be applied to the photomask 507, and the total dose of radiation can follow a pattern to produce, for example... Figure 6 The nanopores 601a to 601n shown are formed by applying radiation with variable dose power or variable time dose.

[0179] The fourteenth process 1314 may include etching a photomask 507 and a cap stack 506. In one embodiment, dry etching may be used, in which a focused electron beam may bombard the photomask 507 and the cap stack 506 to form nanopores 601a to 601n. Other etching techniques may be used.

[0180] The embodiments of the subject matter and operations described in this specification may be implemented in digital electronic circuits or in computer software, firmware, or hardware (including the structures disclosed in this specification and their equivalents), or in a combination of one or more of the foregoing. Embodiments of the subject matter described in this specification may be implemented as one or more computer programs (i.e., one or more modules of computer program instructions) encoded on a computer storage medium for execution by or control of operations by a data processing device. Optionally or additionally, the program instructions may be encoded on artificially generated propagation signals (e.g., machine-generated electrical, optical, or electromagnetic signals) to encode information for transmission to a suitable receiver device for execution by the 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 in a computer-readable storage device, a computer-readable storage substrate, a random or serial access memory array or device, or a combination thereof. Furthermore, although the computer storage medium is not a propagation signal, it may be a source or destination of computer program instructions encoded in artificially generated propagation signals. Computer storage media may also be one or more separate physical components or media (e.g., multiple CDs, disks, or other storage devices), or may be included in one or more separate physical components or media (e.g., multiple CDs, disks, or other storage devices). Furthermore, the operations described in this specification can be implemented as operations performed by a data processing device on data stored on one or more computer-readable storage devices or received from other sources.

[0181] While this specification may contain numerous specific implementation details, these details should not be construed as limiting the scope of any claimed subject matter, but rather as descriptions of features specific to particular embodiments. Certain features described in this specification within the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented separately in multiple embodiments or in any suitable sub-combination. Furthermore, although features may be described above as functioning in certain combinations, and even initially claimed in this way, in some cases one or more features from the claimed combination may be removed from the combination, and the claimed combination may be for sub-combinations or variations thereof.

[0182] Similarly, although operations are depicted in a specific order in the accompanying drawings, this should not be construed as requiring such operations to be performed in the specific order shown or in a sequential order, or to perform all the operations shown to achieve the desired result. In some cases, multitasking and parallel processing can be advantageous. Furthermore, the separation of the various system components in the above embodiments should not be construed as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

[0183] Therefore, specific embodiments of the subject matter have been described herein. Other embodiments are within the scope of the claims. In some cases, the actions set forth in the claims may be performed in a different order and still achieve the desired results. Furthermore, the processes depicted in the drawings do not necessarily require the specific order or sequential order shown to achieve the desired results. In some embodiments, multitasking and parallel processing may be advantageous.

[0184] As those skilled in the art will recognize, the innovative concepts described herein can be modified and varied across a wide range of applications. Therefore, the scope of the claimed subject matter should not be limited to any specific example teachings discussed above, but is defined by the claims.

[0185] Embodiments of the inventive concept can be extended to the following statements without limitation:

[0186] Statement 1: A sensor includes: an aperture, a dispersive array, a lens, an image sensor, and a processor.

[0187] Statement 2: According to the sensor described in Statement 1, the dispersive array further includes one or more dispersive structures that are capable of scattering light in a first wavelength range and dispersing light in a second wavelength range.

[0188] Statement 3: According to the sensor described in Statement 2, at least two dispersive structures include defect layers, wherein the defect layers of the at least two dispersive structures have different thicknesses from each other.

[0189] Statement 4: According to the sensor described in Statement 3, the dispersive structure includes the at least two dispersive structures that disperse light in wavelength ranges that are different from each other.

[0190] Statement 5: According to the sensor described in Statement 3, the dispersive structure causes light to scatter in a first direction, but allows light to pass through substantially without scattering in a second direction.

[0191] Statement 6: According to the sensor described in Statement 3, wherein the at least two dispersive structures comprise rows of nanostructures positioned at different angles to each other.

[0192] Statement 7: According to the sensor described in Statement 3, wherein the at least two dispersive structures comprise a row of nanostructures positioned at the same angle to each other.

[0193] Statement 8: According to the sensor described in Statement 1, the image sensor reads spectral data from light of wavelengths dispersed by the dispersive array.

[0194] Statement 9: According to the sensor described in Statement 8, the processor can reconstruct the spectrum based on the spectral data.

[0195] Statement 10: According to the sensor described in Statement 1, the image sensor is logically subdivided into reading image data from a first group of pixels and reading spectral data from a second group of pixels.

[0196] Statement 11: According to the sensor described in Statement 10, the first group of pixels comprises a circle, and the second group of pixels comprises a ring coaxial with the circle of the first group of pixels.

[0197] Statement 12: According to the sensor described in Statement 10, the processor can reconstruct an image based on image data or reconstruct a spectrum based on spectral data.

[0198] Statement 13: According to the sensor described in Statement 1, the dispersive array provides a constant scattering angle range and a dispersion angle range for incident light input within the incident light input angle range.

[0199] Statement 14: According to the sensor described in Statement 1, the incident light input angle ranges between 0° and + / -30°.

[0200] Statement 15: According to the sensor described in Statement 2, the scattering and dispersion angle ranges are between 0° and + / -15° for a first wavelength range and between 0° and + / -30° for a second wavelength range.

[0201] Statement 16: In the sensor described in Statement 1, the lens may be a superlens.

[0202] Statement 17: In the sensor described in Statement 1, the aperture, dispersive array, and lens are integrated together.

[0203] Statement 18: A method for obtaining data from a sensor, comprising the steps of: receiving incident light, scattering the incident light through a scattering layer to generate scattered light, dispersing a subset of the scattered light through a dispersive layer to generate dispersive light, receiving the dispersive light on an image sensor, and reconstructing spectral data based on the dispersive light.

[0204] Statement 19: The method according to Statement 18, wherein the incident light comprises light from the visible spectrum or the near-infrared (NIR) spectrum.

[0205] Statement 20: According to the method described in Statement 18, the method further includes the steps of: receiving scattered light on an image sensor; and reconstructing an image based on the scattered light.

[0206] Statement 21: The method according to Statement 18, wherein the spectral data includes light from the NIR spectrum.

[0207] Statement 22: According to the method of Statement 18, the incident light is scattered through a scattering layer comprising a nanostructured surface.

[0208] Statement 23: According to the method described in Statement 18, wherein the subset of scattered light is dispersed by a distributed Bragg filter.

[0209] Statement 24: According to the method described in Statement 18, the image data and spectral data are reconstructed simultaneously.

[0210] Statement 25: A dispersion array comprising: at least one dispersion structure, the at least one dispersion structure dispersing light in a target wavelength range starting at 0° dispersion of the target wavelength, wherein the dispersion structure further comprises: a nanostructure layer; and a filter layer.

[0211] Statement 26: The dispersive array according to Statement 25, wherein the nanostructure layer includes nanopores, nanorods or nanoantennas.

[0212] Statement 27: According to the dispersive array described in Statement 25, the nanostructure layer is a dielectric material or a plasma material.

[0213] Statement 28: The dispersive array according to Statement 25, wherein the dispersive structure is tuned to scatter and disperse light related to the target wavelength range.

[0214] Statement 29: According to the dispersive array described in Statement 25, the nanostructure layer further includes nanostructure rows, wherein each nanostructure row is parallel to each other.

[0215] Statement 30: The dispersive array according to Statement 29, wherein each row of nanostructures further includes nanopores.

[0216] Statement 31: The dispersive array according to Statement 30, wherein the nanopores are located in the TiO2 layer.

[0217] Statement 32: According to the dispersive array described in Statement 30, the radius of the nanopore is half or less of the target wavelength within the target wavelength range of the dispersive structure.

[0218] Statement 33: According to the dispersive array described in Statement 30, each nanopore is spaced close enough within the nanostructure row to allow the target wavelength range to pass through the nanostructure row in one dimension with little or no scattering.

[0219] Statement 34: According to the dispersive array described in Statement 29, the nanostructure rows are distributed between the minimum distance and the maximum distance.

[0220] Statement 35: According to the dispersive array described in Statement 34, the rows of nanostructures are randomly distributed between a minimum distance and a maximum distance.

[0221] Statement 36: According to the dispersive array described in Statement 34, the maximum distance between rows of nanostructures is half the length of the longest wavelength in the target wavelength range of the dispersive structure.

[0222] Statement 37: The dispersive array according to Statement 25, wherein the filter layer comprises a distributed Bragg reflector, a dielectric mirror, a fiber Bragg grating, or a semiconductor Bragg mirror.

[0223] Statement 38: According to the dispersive array of Statement 25, the filter layer includes 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, the first layer and the second layer being alternately stacked on top of each other to form a stacked layer.

[0224] Statement 39: The dispersive array according to Statement 38, wherein the first layer comprises TiO2 and the second layer comprises SiO2.

[0225] Statement 40: The dispersive array according to Statement 38, wherein there are at least two sets of stacked layers.

[0226] Statement 41: According to the dispersive array described in Statement 38, the stacked layers enable the dispersive structure to disperse light of a target wavelength.

[0227] Statement 42: The dispersive array according to Statement 38, wherein the dispersive array comprises two or more dispersive structures, and at least one dispersive structure comprises a defect layer.

[0228] Statement 43: The dispersive array according to Statement 42, wherein the dispersive array comprises a plurality of dispersive structures having defect layers, and at least two dispersive structures having defect layers of different thicknesses.

[0229] Statement 44: A method for manufacturing a dispersive array, the method comprising the steps of: depositing a first filter stack on a substrate; depositing a defect layer; depositing a second filter stack; depositing a cap stack; and forming a nanostructure from the cap stack.

[0230] Statement 45: According to the method of statement 44, the step of depositing the first filter stack includes depositing at least one first layer composed of a first material and at least one second layer composed of a second material.

[0231] Statement 46: According to the method described in statement 45, the first material is a dielectric material with a refractive index between 1.6 and 2.7.

[0232] Statement 47: According to the method described in Statement 45, the second material is a dielectric material with a refractive index between 1.3 and 1.6.

[0233] Statement 48: The method according to statement 44, wherein grayscale lithography is used to etch the defect layer.

[0234] Statement 49: According to the method of statement 44, the defect layer comprises a material used in the first filter stack.

[0235] Statement 50: The method according to statement 44, wherein the nanostructure is formed via electron beam lithography or photolithography.

[0236] Statement 51: The method according to statement 44, wherein the nanostructure is formed into one or more dispersive structures.

[0237] Statement 52: According to the method described in Statement 51, the defect layer is etched to different thicknesses for multiple dispersive structures.

Claims

1. A dispersion array, the dispersion array comprising: a plurality of dispersion structures, each of the plurality of dispersion structures dispersing light of a target wavelength range with a 0° dispersion at the target wavelength, wherein each of the plurality of dispersion structures comprises: a nanostructure layer comprising a plurality of rows of nanostructures parallel to each other; and a filter layer on one side of the nanostructure layer and comprising a defect layer, wherein the plurality of rows of nanostructures comprised in each of the plurality of dispersion structures forms an angle with the plurality of rows of nanostructures comprised in another of the plurality of dispersion structures, and wherein the defect layers of the filter layers of the plurality of dispersion structures have different thicknesses from each other.

2. The dispersion array of claim 1, wherein, The nanostructure layer comprises nano-holes, nano-rods, or nano-antennas.

3. The dispersion array of claim 1, wherein, The nanostructure layer comprises a dielectric material or a plasmonic material.

4. The dispersion array of claim 1, wherein, Each of the plurality of dispersion structures is tuned to scatter and disperse light of the target wavelength range.

5. The dispersion array of claim 1, wherein, The rows of nanostructures further comprise nano-holes.

6. The dispersion array of claim 5, wherein, The nano-holes are formed in a TiO2 layer.

7. The dispersion array of claim 5, wherein, The radius of the nano-holes is half or less of a target wavelength within the target wavelength range of each of the plurality of dispersion structures.

8. The dispersion array of claim 5, wherein, The nano-holes are spaced sufficiently close within the rows of nanostructures to allow the target wavelength range to pass through the rows of nanostructures in one dimension without scattering.

9. The dispersion array of claim 1, wherein, The rows of nanostructures are distributed between a minimum distance and a maximum distance.

10. The dispersion array of claim 9, wherein, The rows of nanostructures are randomly distributed between the minimum distance and the maximum distance.

11. The dispersion array of claim 9, wherein, The maximum distance between the rows of nanostructures is half the length of the longest wavelength of the target wavelength range of each of the plurality of dispersion structures.

12. The dispersion array of claim 1, wherein, The filter layer comprises a distributed Bragg reflector, a dielectric mirror, a fiber Bragg grating, or a semiconductor Bragg mirror.

13. The dispersion array of claim 1, wherein, The filter layer further comprises first layers of a first thickness and a first material and second layers of a second thickness and a second material, the first layers and the second layers being stacked on top of each other in an alternating manner to form a stack of layers.

14. The dispersion array of claim 13, wherein, The first layers comprise TiO2 and the second layers comprise SiO2.

15. The dispersive array of claim 13, wherein, There are at least two groups of the stack of layers and the defect layer is interposed between the at least two groups of the stack of layers.

16. The dispersion array of claim 13, wherein, The stack of layers is capable of dispersing light of the target wavelength range of each of the plurality of dispersion structures.

17. A method of manufacturing a dispersion array, the method comprising the steps of: depositing a first filter stack on a substrate; depositing a defect preparation layer and a defect lithography layer on the first filter stack; performing an exposure process and an etching process on the defect lithography layer and the defect preparation layer to form a defect layer by using a gray-scale lithography technique; depositing a second filter stack on the defect layer; depositing a cap stack on the second filter stack 505; and forming a nanostructure layer from the cap stack 506, wherein the nanostructure layer is comprised in each of a plurality of dispersion structures and comprises a plurality of rows of nanostructures parallel to each other, wherein the plurality of rows of nanostructures comprised in each of the plurality of dispersion structures forms an angle with the plurality of rows of nanostructures comprised in another of the plurality of dispersion structures, and wherein the defect layer is etched to different thicknesses for the plurality of dispersion structures.

18. The method of claim 17, wherein, The step of depositing the first filter stack includes depositing a first layer of at least one first material composition and a second layer of at least one second material composition.

19. The method of claim 18, wherein, The first material has a refractive index between 1.6 and 2.

7.

20. The method of claim 18, wherein, The second material has a refractive index between 1.3 and 1.

6.

21. The method of claim 17, wherein, The defect layer comprises a material used in the first filter stack.

22. The method of claim 17, wherein, The nanostructured layer is formed via e-beam lithography or photolithography.

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