Systems and methods for on-chip polarization routing

Abstract

To provide systems, methods, and devices for routing the polarization state of light towards a photodetector of a polarization sensor.SOLUTION: In one or more examples, a system, device, and method for on-chip polarization routing are provided, the method comprising: routing a first polarization of light to a first wire grid of a wire grid array; routing a second polarization of light different from the first polarization of light to a second wire grid of the wire grid array; and filtering, via the wire grid array, the first polarization of light and the second polarization of light to sensor pixels of the photodetector.SELECTED DRAWING: Figure 14

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 647,610, filed May 14, 2024, the disclosure of which is incorporated by reference in its entirety as if fully set forth herein.

[0002] The present disclosure relates generally to memory systems. More specifically, the subject matter disclosed herein relates to improvements to image or polarization sensors using on-chip polarization routing. Summary of the Invention

[0003] Polarization can include the property of light that indicates the direction of vibration of an electromagnetic field. Polarizers and / or filters can be used to direct electromagnetic vibrations in a given direction or to direct them to a given location.

[0004] Polarization sensors can include image sensors configured to detect the polarization of light, meaning they can measure the direction in which light waves are vibrating. Polarization sensors can provide information about surface properties not detectable by cameras in the visible spectrum, such as stress levels within materials or the orientation of reflective surfaces. Polarization image sensors can reliably distinguish differences in the degree of polarization between uneven areas, accurately capturing scratches with specific orientations and distinguishing them from stains with random irregularities. Polarization sensors can capture the polarization angle of light beyond light intensity and color, making them useful in applications such as industrial inspection, scientific research, and medical sensors.

[0005] Polarization can be based on the properties of light that indicate the direction of electromagnetic field oscillations. Polarizers / filters can be used to direct the electromagnetic oscillations to specific locations. Some systems for detecting polarization states may use different polarizer filters on top of the image sensor that can attenuate undesired polarization states, thereby reducing the optical signal. Some systems can route undesired polarizations from other pixels to the target pixel to improve light collection efficiency. However, such systems can increase crosstalk and have a relatively low extinction ratio.

[0006] To overcome these problems, systems and methods for image sensors or polarization sensors using on-chip polarization routing are described herein. The described systems and methods can include combining an on-chip optical router and optical filter to enhance signal collection, increase signal-to-noise ratio, increase extinction ratio, and reduce crosstalk. Crosstalk can refer to unwanted signal interference, where light intended for a first photodetector (PD) pixel is detected by a second PD pixel, resulting in reduced signal quality. Extinction ratio can refer to the ratio of an electrical signal (e.g., representing a binary 1) generated when a high optical power level is received compared to a signal (e.g., representing a binary 0) generated when a low optical power level is received, with a higher extinction ratio indicating better discrimination between high and low levels.

[0007] The systems and methods described herein can provide high-performance on-chip polarization sensors that combine polarization routing and filtering with full-Stokes detection capabilities (e.g., for machine vision, healthcare, etc.).

[0008] The systems and methods include several advantages. For example, the described systems and methods avoid the 25% efficiency limit of some systems (e.g., 2x2 polarization pixel systems). In some embodiments, the systems and methods add the polarization routing capabilities of an on-chip polarization sensor to enhance signal collection. In some examples, the described systems and methods combine an on-chip polarization router and filter to improve signal collection, increase the signal-to-noise ratio (SNR), improve the extinction ratio (ER), and / or reduce crosstalk.

[0009] The described systems and methods can include a polarization filter that can include a wire grid (e.g., a wire grid array with a metal and / or metal oxide layer). The polarization filter can induce phase modulation for polarization routing and focusing of incident light (e.g., based on metastructures with high refractive index dielectrics). In some embodiments, the systems and methods can be based on one or more polarization filters with one or more microlenses. For example, a given system can include a 2x2 polarization filter and a microlens for every 2x2 pixel. In some embodiments, the described systems and methods can include a 1x1 (single) polarization filter or a 1x2 (bisecting) polarization filter and a microlens for every 2x2 pixel.

[0010] The above approach improves upon previous methods because the described systems and methods avoid the efficiency limitations of some systems (e.g., the 25% limit in 2x2 polarization pixel systems). In some embodiments, the systems and methods add the polarization routing capabilities of an on-chip polarization sensor to enhance signal collection. In some examples, the described systems and methods combine an on-chip polarization router and filter to improve signal collection, increase signal-to-noise ratio (SNR), improve extinction ratio (ER), and / or reduce crosstalk.

[0011] In some aspects, the technology described herein relates to a polarization sensor, the polarization sensor including: a metastructure including two or more nanostructure patterns configured to route polarization states of light toward a photodetector of the polarization sensor, the two or more nanostructure patterns including a first nanostructure pattern configured to route light of a first polarization to a first wire grid of a wire grid array and a second nanostructure pattern configured to route light of a second polarization, different from the first polarization, to a second wire grid of the wire grid array; and a wire grid array configured to filter light of the first polarization and light of the second polarization to sensor pixels of the photodetector.

[0012] In some aspects, the technology described herein relates to a polarization sensor, wherein a first wire grid of a wire grid array is configured to allow light of a first polarization at a first wavelength to pass to a first sensor pixel of a photodetector and to reflect or absorb light of a second polarization away from the first sensor pixel of the photodetector, and a second wire grid of the wire grid array is configured to allow light of a second polarization at the first wavelength to pass to a second sensor pixel of the photodetector and to reflect or absorb light of the first polarization away from the second sensor pixel of the photodetector.

[0013] In some embodiments, the technology described herein relates to a polarization sensor, wherein a first nanostructure pattern is configured to route light of a first wavelength to a first wire grid of a wire grid array, and a second nanostructure pattern is configured to route light of a second wavelength, different from the first wavelength, to a second wire grid of the wire grid array.

[0014] In some embodiments, the technology described herein relates to a polarization sensor further including a third nanostructure pattern of the metastructure configured to route light of a third polarization to a third wire grid of a wire grid array, and a fourth nanostructure pattern of the metastructure configured to route light of a fourth polarization, different from the third polarization, to a fourth wire grid of the wire grid array.

[0015] In some aspects, the technology described herein relates to a polarization sensor, wherein a third wire grid of the wire grid array is configured to allow light of a third polarization to pass through to a third sensor pixel of the photodetector and to reflect or absorb light of a fourth polarization away from the third sensor pixel, and a fourth wire grid of the wire grid array is configured to allow light of the fourth polarization to pass through to a fourth sensor pixel of the photodetector and to reflect or absorb light of the third polarization away from the fourth sensor pixel of the photodetector.

[0016] In some embodiments, the technology described herein relates to a polarization sensor, wherein a first nanostructured pattern includes N nanostructured elements that repeat at least once within the metastructure, and a second nanostructured pattern includes M nanostructured elements that repeat at least once within the metastructure, wherein the M nanostructured elements are less than, more than, or equal to the N nanostructured elements.

[0017] In some embodiments, the technology described herein relates to a polarization sensor, wherein a first nanostructured element of N nanostructured elements has a phase difference with a second nanostructured element of the N nanostructured elements, the phase difference being based on the quotient of π and N.

[0018] In some embodiments, the technology described herein relates to a polarization sensor, wherein the width of a first nanostructure element of a set of repeating nanostructure elements of the metastructure does not match the length of the first nanostructure element, the rotational orientation of the first nanostructure element matches the rotational orientation of a second nanostructure element of the set of repeating nanostructure elements, or the rotational orientation of a third nanostructure element of the set of repeating nanostructure elements does not match the rotational orientation of a fourth nanostructure element of the set of repeating nanostructure elements.

[0019] In some embodiments, the technology described herein relates to a polarization sensor, wherein the width of the third nanostructured element does not match the width of the fourth nanostructured element, or the length of the third nanostructured element does not match the length of the fourth nanostructured element.

[0020] In some embodiments, the technology described herein relates to a polarization sensor, wherein the width of a fifth nanostructure element of the metastructure matches the width of a sixth nanostructure element of the metastructure, and the length of the fifth nanostructure element of the metastructure matches the length of the sixth nanostructure element of the metastructure.

[0021] In some aspects, the technology described herein relates to a polarization sensor in which light passes through at least one of a global lens, a microlens, or an anti-reflection layer of the polarization sensor to reach the metastructure.

[0022] In some aspects, the technology described herein relates to a polarization sensor, the polarization sensor including a capping layer between a metastructure and a wire grid array, the wire grid array adjacent to a photodetector, and the capping layer including a refractive index of 3 or less.

[0023] In some aspects, the technology described herein relates to a polarization sensor, wherein the first polarization or the second polarization comprises horizontal polarization, vertical polarization, diagonal polarization, reverse diagonal polarization, right-handed circular polarization, or left-handed circular polarization.

[0024] In some embodiments, the technology described herein relates to a polarization sensor, wherein the metastructure comprises at least one layer of nanostructured elements, at least one of the layers comprising a relatively high refractive index dielectric material.

[0025] In some aspects, the technology described herein relates to a polarization sensor, wherein the wire grid array includes at least one of an array of metal wires and a substrate.

[0026] In some aspects, the technology described herein relates to a system including at least one polarization sensor, the at least one polarization sensor being a metastructure including two or more nanostructure patterns configured to route polarization states of light toward a photodetector of the polarization sensor, the two or more nanostructure patterns including a first nanostructure pattern configured to route light of a first polarization to a first wire grid of a wire grid array and a second nanostructure pattern configured to route light of a second polarization, different from the first polarization, to a second wire grid of the wire grid array; and a wire grid array configured to filter light of the first polarization and light of the second polarization toward sensor pixels of the photodetector.

[0027] In some aspects, the techniques described herein relate to a system, wherein a first wire grid of a wire grid array is configured to allow light of a first polarization at a first wavelength to pass to a first sensor pixel of a photodetector and to reflect light of a second polarization away from the first sensor pixel of the photodetector, and a second wire grid of the wire grid array is configured to allow light of a second polarization at the first wavelength to pass to a second sensor pixel of the photodetector and to reflect light of the first polarization away from the second sensor pixel of the photodetector.

[0028] In some embodiments, the technology described herein relates to a system, wherein a first nanostructured pattern is configured to route light of a first wavelength to a first wire grid of a wire grid array, and a second nanostructured pattern is configured to route light of a second wavelength, different from the first wavelength, to a second wire grid of the wire grid array.

[0029] In some aspects, the techniques described herein relate to a method for routing polarization states of light toward a photodetector of a polarization sensor, the method including: routing light of a first polarization to a first wire grid of a wire grid array using a first nanostructure pattern of a metastructure; routing light of a second polarization, different from the first polarization, to a second wire grid of the wire grid array using a second nanostructure pattern of the metastructure; and filtering the light of the first polarization and the light of the second polarization toward sensor pixels of the photodetector using the wire grid array.

[0030] In some aspects, the techniques described herein relate to a method, wherein a first wire grid of a wire grid array is configured to allow light of a first polarization at a first wavelength to pass to a first sensor pixel of a photodetector and to reflect light of a second polarization away from the first sensor pixel of the photodetector, and a second wire grid of the wire grid array is configured to allow light of a second polarization at the first wavelength to pass to a second sensor pixel of the photodetector and to reflect light of the first polarization away from the second sensor pixel of the photodetector. [Brief explanation of the drawings]

[0031] In the following sections, aspects of the presently disclosed subject matter are described with reference to exemplary embodiments illustrated in the drawings, including the following figures: [Figure 1] 1 illustrates an example of a system according to one or more embodiments described herein. [Figure 2] 1 illustrates an example of a system according to one or more embodiments described herein. [Figure 3] 1 illustrates an example of a system according to one or more embodiments described herein. [Figure 4] 1 illustrates an example of a meta structure in accordance with one or more embodiments described herein. [Figure 5] 1 illustrates an example of a system according to one or more embodiments described herein. [Figure 6] 1 illustrates an example of a system according to one or more embodiments described herein. [Figure 7] 1 illustrates an example of a meta structure in accordance with one or more embodiments described herein. [Figure 8] 8-12 show example patterns according to one or more embodiments described herein. [Figure 9] 8-12 show example patterns according to one or more embodiments described herein. [Figure 10] 8-12 show example patterns according to one or more embodiments described herein. [Figure 11] 8-12 show example patterns according to one or more embodiments described herein. [Figure 12] 8-12 show example patterns according to one or more embodiments described herein. [Figure 13] 1 illustrates an example of a system according to one or more embodiments described herein. [Figure 14] 1 shows a flow diagram illustrating an example method associated with the disclosed system, according to example embodiments described herein. [Figure 15] 1 shows a flow diagram illustrating an example method associated with the disclosed system, according to example embodiments described herein. [Figure 16] 1 shows a flow diagram illustrating an example method associated with the disclosed system, according to example embodiments described herein. DETAILED DESCRIPTION OF THE INVENTION

[0032] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be understood by those skilled in the art that the disclosed aspects may be practiced without these specific details. Additionally, well-known methods, procedures, components, and circuits have not been described in detail so as not to obscure the subject matter disclosed herein.

[0033] Throughout this specification, a reference to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with that embodiment may be included in at least one embodiment disclosed herein. Thus, the appearances of the phrases "in one embodiment," "in an embodiment," or "according to one embodiment" (or other phrases of similar meaning) in various places throughout this specification may not necessarily all refer to the same embodiment. Or, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In this regard, as used herein, the term "exemplary" means "serving as an example or illustration." Any embodiment described as "exemplary" should not be construed as necessarily preferred or advantageous over other embodiments. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Also, singular terms may include their corresponding plurals, and plural terms may include their corresponding singulars, depending on the context of the description herein. Similarly, hyphenated terms (e.g., "two-dimensional," "pre-determined," "pixel-specific," etc.) may sometimes be used interchangeably with their corresponding non-hyphenated versions (e.g., "two dimensional," "predetermined," "pixel specific," etc.), and capitalized inputs (e.g., "Counter Clock," "Row Select," "PIXOUT," etc.) may sometimes be used interchangeably with their corresponding non-capitalized versions (e.g., "counter clock," "row select," "pixout," etc.). Such occasional interchangeable uses should not be considered to be mutually exclusive.

[0034] Also, where appropriate in the context of the description herein, singular terms can include the corresponding plural, and plural terms can include the corresponding singular. It should further be noted that the various figures (including the component figures) shown and described herein are for illustrative purposes only and are not drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Also, where considered appropriate, reference numerals have been repeated among the figures to indicate corresponding and / or similar elements.

[0035] The terminology used herein is merely for the purpose of describing some example embodiments and is not intended to limit the claimed subject matter. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. It is further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0036] It is understood that when an element or layer is referred to as being on, "connected to," or "coupled to" another element or layer, it can be directly on, connected to, or coupled to that other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly connected to," or "directly coupled to" another element or layer, there are no intervening elements or layers present. Like numbers refer to like elements throughout. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0037] The terms "first," "second," etc., as used herein, are used as labels for the noun that follows them, and do not imply any type of ordering (e.g., spatial, temporal, logical, etc.), unless explicitly defined as such. Also, the same reference numerals may be used across two or more figures to refer to parts, components, blocks, circuits, units, or modules having the same or similar functions. However, such usage is merely for ease of illustration and ease of description, and does not imply that the configuration or architectural details of those components or units are the same across all embodiments, or that such commonly referenced parts / modules are the only means for implementing some of the example embodiments disclosed herein.

[0038] Unless otherwise specified, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this subject matter belongs. It is further understood that terms, such as those defined in commonly used dictionaries, should be interpreted to have a meaning consistent with their meaning in the context of the relevant art, and not in an idealized or overly formal sense unless expressly so defined herein.

[0039] As used herein, the term "module" refers to any combination of software, firmware, and / or hardware configured to provide the functionality described herein with respect to the module. For example, software may be embodied as a software package, code, and / or instruction set or instructions, and the term "hardware," as used in any implementation described herein, may include, for example, assemblies, hardwired circuitry, programmable circuitry, state machine circuitry, and / or firmware storing instructions executed by programmable circuitry, alone or in any combination. Modules, collectively or individually, may be embodied as circuits that form part of a larger system, such as, but not limited to, an integrated circuit (IC), a system-on-chip (SoC), an assembly, etc.

[0040] 1 illustrates an example system 100 in accordance with one or more embodiments described herein. In some configurations, one or more aspects of system 100 may be implemented by or in conjunction with a polarization sensor.

[0041] In the illustrated example, system 100 may include lens 105, metastructure 110 (e.g., optical routing metastructure, polarization routing metastructure), filter 115 (e.g., polarization filter), and one or more sensor pixels (e.g., sensor pixel array 120 of photodetectors). In some embodiments, lens 105 may include a global lens, one or more microlenses, and / or one or more anti-reflection layers (e.g., one or more anti-glare layers to reduce the amount of light reflected from lens 105 and allow more light to pass through). In some examples, filter 115 may include one or more filter elements (e.g., filter 115-a, filter 115-b, filter 115-c). In the illustrated example, sensor pixel array 120 may include at least one pixel (e.g., pixel 120-a, pixel 120-b, and pixel 120-c).

[0042] In the illustrated example, light entering system 100 may include one or more polarization states (e.g., a first polarization state, a second polarization state, a third polarization state, etc.). The incident light may pass through lens 105 and reach metastructure 110. Metastructure 110 may include one or more nanostructured elements. The one or more nanostructured elements of metastructure 110 may be configured to route and / or focus the light entering lens 105. In some embodiments, metastructure 110 may route and / or focus the light based on one or more wavelengths (e.g., one or more wavelength ranges) of the light and / or one or more polarization states of the light. As shown, metastructure 110 may route and / or focus a first wavelength (e.g., a first wavelength range) and / or a first polarization state of the incident light toward filter 115-a. In some examples, the metastructure 110 may route and / or focus a second wavelength (e.g., a second wavelength range) and / or a second polarization state of the incident light toward filter 115-b. In some embodiments, the metastructure 110 may route and / or focus a third polarization state of the incident light toward filter 115-c. In some examples, the metastructure 110 may route and / or focus light of a first wavelength (e.g., a first wavelength range) and a first polarization toward filter 115-a and route and / or focus light of a first wavelength (e.g., a first wavelength range) and / or a second wavelength (e.g., a second wavelength range) and a second polarization toward filter 115-b. In some embodiments, the metastructure 110 may route and / or focus light of one or more wavelengths (e.g., one or more wavelength ranges) and a first polarization toward filter 115-a. In some examples, metastructure 110 can route and / or focus light of a second polarization of one or more wavelengths (e.g., one or more wavelength ranges) toward filter 115-b, and at least one wavelength (e.g., at least one wavelength range) of the light of the first polarization can match or overlap with at least one wavelength of the light of the second polarization.In some embodiments, no wavelength or range of wavelengths of light of the first polarization coincides with or overlaps with the wavelength or range of wavelengths of light of the second polarization.

[0043] The nanostructured elements of the metastructure 110 may be formed from materials with relatively high dielectric constants, such as amorphous silicon (a-Si), crystalline silicon (c-Si), polysilicon (p-Si), silicon nitride (Si3N4), titanium dioxide (TiO2), gallium nitride (GaN), zinc oxide (ZnO), hafnium silicate, zirconium silicate, hafnium dioxide, and zirconium dioxide.

[0044] As shown, filter 115-a can be configured to allow light of a first wavelength (e.g., a first wavelength range) and / or a first polarization state to pass to pixel 120-a (e.g., blocking other polarization states), filter 115-b can be configured to allow light of a second wavelength (e.g., a second wavelength range) and / or a second polarization state to pass to pixel 120-b (e.g., blocking other polarization states), and / or filter 115-c can be configured to allow light of a third wavelength (e.g., a third wavelength range) and / or a third polarization state to pass to pixel 120-c (e.g., blocking other polarization states).

[0045] 2 illustrates an example system 200 according to one or more embodiments described herein. In some configurations, one or more aspects of system 200 may be implemented by or in conjunction with a polarization sensor. In the illustrated example, system 200 may include a microlens 205, a filter 210, and a sensor pixel 215. In some embodiments, filter 210 may be an example of metastructure 110 and / or filter 115 of FIG. 1. Sensor pixel 215 may be an example of sensor pixel array 120 of FIG. 1.

[0046] As shown, the microlens 205 may include one or more elements (e.g., a 1×2 microlens, a bisecting microlens). In the illustrated example, light may pass through the microlens 205 to the filter 210. In some examples, the filter 210 may include metastructures (e.g., nanostructured elements) configured to route incident light based on a property of the light. In some embodiments, the filter 210 may include one or more filters that filter the incident light based on a property of the light. For example, the filter 210 may route a first polarization state (e.g., horizontally polarized) of the incident light toward a first one of the sensor pixels 215, a second polarization state (e.g., vertically polarized) of the incident light toward a second one of the sensor pixels 215, a third polarization state (e.g., diagonally polarized or right-handed circularly polarized) of the incident light toward a third one of the sensor pixels 215, and / or a fourth polarization state (e.g., reverse diagonally polarized or left-handed circularly polarized) of the incident light toward a fourth one of the sensor pixels 215.

[0047] 3 illustrates an example system 300 according to one or more embodiments described herein. In some configurations, one or more aspects of system 300 may be implemented by or in conjunction with a polarization sensor. In some configurations, one or more aspects of system 300 may be implemented by or in conjunction with one or more components of system 100 of FIG. 1 , one or more components of system 200 of FIG. 2 , or any combination thereof. In the illustrated example, system 300 may include a global lens 305, a microlens 310, an anti-reflection layer 315, a metastructure 320, a capping layer 325, a wire grid array 330, and a sensor pixel array 335.

[0048] As shown, light may pass through global lens 305 to microlens 310. Microlens 310 may include at least one microlens (e.g., microlens 310-a and microlens 310-b). In some embodiments, microlens 310-a may pass a first portion of incident light to anti-reflective layer 315, and microlens 310-b may pass a second portion of incident light to anti-reflective layer 315. Anti-reflective layer 315 may include one or more anti-glare layers to reduce the amount of light reflected back toward microlens 310 and allow more of the incident light to pass through to metastructure 320.

[0049] In some examples, the metastructure 320 can include one or more layers (e.g., one or more layers of nanostructures). For example, the metastructure 320 can include up to 12 metastructure layers. The metastructure 320 can route light toward the wire grid array 330 through the capping layer 325. In some embodiments, the capping layer 325, in conjunction with the metastructure 320, can be configured to route light toward the wire grid array 330. The capping layer 325 can include a relatively low refractive index (e.g., less than 2). The capping layer 325 can be made of, for example, aluminum oxide (Al2O3), silicon dioxide (SiO2), silicon nitride (Si3N4), silicon oxynitride (Si x N y O z The capping layer 325 may include a dielectric or polymer, such as silicon dioxide (SiO), photoresist, epoxy resin, and / or other materials. The capping layer 325 may be formed on the wire grid and / or on the surface of the detector substrate. The capping layer 325 may be substantially optically transparent and may be formed by chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), physical vapor deposition (PVD), atomic layer deposition (ALD), evaporation, spin-on coating, and / or other processes.

[0050] As shown, metastructure 320 may include at least one metastructure (e.g., metastructure 320-a and metastructure 320-b). Metastructure 320-a may be adjacent to metastructure 320-b, microlens 310-a may be aligned with metastructure 320-a, and / or microlens 310-b may be aligned with metastructure 320-b. In some embodiments, metastructure 320-a may include at least one metastructure layer, and / or metastructure 320-b may include at least one metastructure layer. In some embodiments, metastructure 320-a and metastructure 320-b may route light based on one or more properties of the light (e.g., the polarity of the light, the wavelength of the light). For example, metastructure 320-a may be configured to route light of a first wavelength (e.g., a first wavelength range) and / or a first polarization state (e.g., horizontally polarized) toward wire grid 330-a, and route incident light of a second wavelength (e.g., a second wavelength range) and / or a second polarization state (e.g., vertically polarized) toward wire grid 330-b. In some examples, metastructure 320-b may be configured to route incident light of a third wavelength (e.g., a third wavelength range) and / or a third polarization state (e.g., diagonally polarized or right-handed circularly polarized) toward wire grid 330-c, and route incident light of a fourth wavelength (e.g., a fourth wavelength range) and / or a fourth polarization state (e.g., reverse diagonally polarized or left-handed circularly polarized) toward wire grid 330-d.

[0051] As shown, wire grid array 330 may include at least one wire grid (e.g., wire grid 330-a, wire grid 330-b, wire grid 330-c, and / or wire grid 330-d). In some examples, wire grid array 330 may filter light based on one or more characteristics of the light. For example, wire grid 330-a can be configured to allow a first wavelength and / or a first polarization state to pass through to pixel 335-a (e.g., while blocking other wavelengths and / or polarization states), wire grid 330-b can be configured to allow a second wavelength and / or a second polarization state to pass through to pixel 335-b (e.g., while blocking other wavelengths and / or polarization states), wire grid 330-c can be configured to allow a third wavelength and / or a third polarization state to pass through to pixel 335-c (e.g., while blocking other wavelengths and / or polarization states), and wire grid 330-d can be configured to allow a fourth wavelength and / or a fourth polarization state to pass through to pixel 335-d (e.g., while blocking other wavelengths and / or polarization states).

[0052] FIG. 4 illustrates an example metastructure 400 according to one or more embodiments described herein. In some configurations, one or more aspects of metastructure 400 may be implemented by or in conjunction with a polarization sensor. In some configurations, one or more aspects of metastructure 400 may be implemented by or in conjunction with one or more components of system 100 of FIG. 1 , one or more components of system 200 of FIG. 2 , or any combination thereof. In the illustrated example, metastructure 400 may include metastructure 405 and metastructure 410. In some embodiments, metastructure 405 may include one or more layers, and / or metastructure 410 may include one or more layers. Although reference is made throughout the description provided to routing the polarization state of light, routing may include routing the polarization state of light and / or the wavelength (e.g., wavelength range) of light.

[0053] In the illustrated example, metastructure 405 and metastructure 410 can each include one or more nanostructured elements. In some embodiments, metastructure 405 and / or metastructure 410 can include several repeated nanostructured elements. For example, metastructure 405 can include an array of elements 415 having several nanostructured elements, where in the illustrated example metastructure 405, array of elements 415 can repeat itself at least once vertically and / or at least once horizontally. As shown, metastructure 410 can include an array of elements 420 having several nanostructured elements, where in the illustrated example metastructure 410, array of elements 420 can repeat itself at least once vertically and / or at least once horizontally. In some embodiments, array of elements 415 and / or array of elements 420 can include one or more nanostructured elements (e.g., up to 100 nanostructured elements). In the illustrated example, element array 415 can include four nanostructured elements, and element array 420 can include four nanostructured elements.

[0054] As shown, the metastructure 405 can be configured to route at least one of the first polarization state and / or the second polarization state. In some examples, the first polarization state can include horizontal polarization, and the second polarization state can include vertical polarization. In some embodiments, the first polarization state and / or the second polarization state can each include other polarization states (e.g., diagonal polarization, reverse diagonal polarization, right-handed circular polarization, left-handed circular polarization). As shown, the metastructure 405 can route and / or focus the first polarization state toward a first target location (e.g., toward a first wire grid and / or a first sensor pixel of a photodetector). In some embodiments, the metastructure 405 can route and / or focus the second polarization state toward a second target location (e.g., toward a second wire grid and / or a second sensor pixel of a photodetector).

[0055] As shown, the metastructure 410 can be configured to route at least one of a third polarization state and / or a fourth polarization state. In some examples, the third polarization state can include a diagonal polarization, and the fourth polarization state can include an anti-diagonal polarization. In some embodiments, the third polarization state can include a right-handed circular polarization, and the fourth polarization state can include a left-handed circular polarization. In some embodiments, the third polarization state and / or the fourth polarization state can each include other polarization states (e.g., horizontal polarization, vertical polarization). As shown, the metastructure 410 can route and / or focus the third polarization state toward a third target location (e.g., toward a third wire grid and / or a third sensor pixel of a photodetector). In some embodiments, the metastructure 410 can route and / or focus the fourth polarization state toward a fourth target location (e.g., toward a fourth wire grid and / or a fourth sensor pixel of a photodetector).

[0056] In some examples, a given nanostructured element of metastructure 405 and / or metastructure 410 may include one or more dimensions 425. Note that a nanostructured element may have a width dimension (e.g., in the x-axis), a length dimension (e.g., in the y-axis), and a height (e.g., in the z-axis). As shown, the dimension 425 of a given nanostructured element may include at least one of a width (e.g., Dx), a length (e.g., Dy), and / or a rotation angle (e.g., θ). In some embodiments, the nanostructured element may be rectangular, cylindrical, triangular, and / or some other shape. In some embodiments, metastructure 400 may depict a top view of a nanostructured element. In some embodiments, metastructure 400 may depict a side view of a nanostructured element.

[0057] In some examples, within a given array of elements, the magnitude of Dx is not equal to the magnitude of Dy to route horizontally polarized, vertically polarized, diagonal polarized, reverse diagonal polarized, right-handed circularly polarized, and / or left-handed circularly polarized light through the metastructure 400. Within a given array of elements, the rotation angle can be equal to zero to route horizontally polarized and / or vertically polarized light through the metastructure 400. Within a given array of elements, the Dx of a first element of the given array of elements can be different from the Dx of a second element of the given array of elements, and / or the Dy of a first element of the given array of elements can be different from the Dy of a second element of the given array of elements. In some embodiments, within a given array of elements, the rotation angle can be non-zero (e.g., avoiding θ=0 degrees) to route diagonally polarized, reverse diagonal polarized, right-handed circularly polarized, and / or left-handed circularly polarized light through the metastructure 400. In some embodiments, the rotation angle can vary within elements of a given array and / or can remain constant within elements of a given array to route diagonally polarized light, reverse diagonally polarized light, right-handed circularly polarized light, and / or left-handed circularly polarized light through metastructure 400. To route right-handed and / or left-handed circularly polarized light through metastructure 400, the Dx of a first element of the elements of a given array can match the Dx of a second element of the elements of the given array and / or the Dy of a first element of the elements of a given array can match the Dy of a second element of the elements of the given array.

[0058] In some examples, the nanostructured elements of metastructure 405 and / or metastructure 410 can provide a phase shift of up to 2π radians to incident light based on the number of nanostructured elements in a given array of elements (e.g., array of elements 415, array of elements 420). For example, adjacent nanostructures can include a phase difference of 2π / n, where n represents the number of elements in a given array of elements. For example, if there are four nanostructures in a given array of elements, as shown in 430, the first nanostructured element can induce a phase modulation of 0 radians to the incident light, the second nanostructured element can induce a phase modulation of π / 2 radians to the incident light, the third nanostructured element can induce a phase modulation of π radians to the incident light, and the fourth nanostructured element can induce a phase modulation of 3π / 2 radians to the incident light.

[0059] Based on the systems and methods described herein, the metastructure 400 can improve the light collection efficiency of a given system (e.g., a polarization sensor). For example, based on the metastructure 400, the described systems and methods avoid the efficiency limitations of some systems (e.g., the 25% limit in a 2x2 polarization pixel system), and the metastructure 400 provides improved light collection efficiency for multiple polarization states (e.g., 44.89% collection efficiency for horizontally polarized light, 43.29% collection efficiency for vertically polarized light, 44.59% collection efficiency for left-handed circularly polarized light, and 44.61% collection efficiency for right-handed circularly polarized light).

[0060] FIG. 5 illustrates an example system 500 according to one or more embodiments described herein. In some configurations, one or more aspects of system 500 may be implemented by or in conjunction with a polarization sensor. In some configurations, one or more aspects of system 500 may be implemented by or in conjunction with one or more components of system 100 of FIG. 1 , one or more components of system 200 of FIG. 2 , or any combination thereof. In the illustrated example, system 500 may include a microlens 505, a filter 510, and a sensor pixel 515. In some embodiments, filter 510 may be an example of metastructure 110 and / or filter 115 of FIG. 1 . Sensor pixel 515 may be an example of sensor pixel array 120 of FIG. 1 .

[0061] As shown, the microlens 505 may include one or more elements (e.g., a 1×1 microlens, a single microlens). In the illustrated example, light may pass through the microlens 505 to the filter 510. In some examples, the filter 510 may include a metastructure (e.g., a nanostructure element) configured to route the incident light based on a property of the light. In some embodiments, the filter 510 may include one or more filters that filter the incident light based on a property of the light. For example, the filter 510 may route a first polarization state (e.g., horizontally polarized) of the incident light toward a first one of the sensor pixels 515, a second polarization state (e.g., vertically polarized) of the incident light toward a second one of the sensor pixels 515, a third polarization state (e.g., diagonally polarized or right-handed circularly polarized) of the incident light toward a third one of the sensor pixels 515, and / or a fourth polarization state (e.g., reverse diagonally polarized or left-handed circularly polarized) of the incident light toward a fourth one of the sensor pixels 515.

[0062] 6 illustrates an example system 600 according to one or more embodiments described herein. In some configurations, one or more aspects of system 600 may be implemented by or in conjunction with a polarization sensor. In some configurations, one or more aspects of system 600 may be implemented by or in conjunction with one or more components of system 100 of FIG. 1 , one or more components of system 200 of FIG. 2 , or any combination thereof. In the illustrated example, system 600 may include a global lens 605, a microlens 610, an anti-reflection layer 615, a metastructure 620, a capping layer 625, a wire grid array 630, and a sensor pixel array 635.

[0063] As shown, light may pass through global lens 605 to microlens 610. Microlens 610 (e.g., a single microlens) may pass incident light to anti-reflective layer 615. Anti-reflective layer 615 may include one or more anti-glare layers to reduce the amount of light reflected back toward microlens 610 and allow more of the incident light to pass through to metastructure 620.

[0064] In some examples, metastructure 620 may include one or more layers (e.g., one or more layers of nanostructures). For example, metastructure 620 may include up to 12 metastructure layers. Metastructure 620 may route light toward wire grid array 630 through capping layer 625. In some embodiments, capping layer 625 may be configured, in conjunction with metastructure 620, to route light toward wire grid array 630. Capping layer 625 may include a relatively low refractive index (e.g., less than 2). In some embodiments, capping layer 625 may improve brightness and / or power efficiency in routing light toward wire grid array 630. As shown, wire grid array 630 may include at least one wire grid (e.g., wire grid 630-a, wire grid 630-b, wire grid 630-c, and / or wire grid 630-d).

[0065] In some embodiments, metastructure 620 may route light based on one or more characteristics of the light (e.g., polarization of the light, wavelength of the light, etc.). For example, metastructure 620 may route light of a first wavelength (e.g., a first wavelength range) and / or a first polarization state (e.g., horizontally polarized) toward wire grid 630-a, route incident light of a second wavelength (e.g., a second wavelength range) and / or a second polarization state (e.g., vertically polarized) toward wire grid 630-b, route incident light of a third wavelength (e.g., a third wavelength range) and / or a third polarization state (e.g., diagonally polarized or right-handed circularly polarized) toward wire grid 630-c, and / or route incident light of a fourth wavelength (e.g., a fourth wavelength range) and / or a fourth polarization state (e.g., reverse diagonally polarized or left-handed circularly polarized) toward wire grid 630-d. Thus, metastructure 620 can be configured to receive light containing up to four polarization states and / or wavelengths and route these four polarization states and / or wavelengths to different target locations. Based on the systems and methods described herein, metastructure 620 can improve the light collection efficiency of a given system (e.g., up to or relatively close to 100% light collection efficiency).

[0066] In some examples, wire grid array 630 may filter light based on one or more characteristics of the light. For example, wire grid 630-a can be configured to allow a first wavelength and / or a first polarization state to pass through to pixel 635-a (e.g., while blocking other wavelengths and / or polarization states), wire grid 630-b can be configured to allow a second wavelength and / or a second polarization state to pass through to pixel 635-b (e.g., while blocking other wavelengths and / or polarization states), wire grid 630-c can be configured to allow a third wavelength and / or a third polarization state to pass through to pixel 635-c (e.g., while blocking other wavelengths and / or polarization states), and wire grid 630-d can be configured to allow a fourth wavelength and / or a fourth polarization state to pass through to pixel 635-d (e.g., while blocking other wavelengths and / or polarization states).

[0067] Thus, the systems and methods described herein provide polarization sensors using on-chip polarization routing. A given system may include a lens, at least one microlens, at least one metastructure, a wire grid array, and / or at least one photodetector. The metastructure may include anisotropic nanostructures (e.g., nanostructured elements of varying width, length, and / or rotational orientation).

[0068] In some examples, the metastructure may filter and route by polarization state or by polarization state and wavelength range to a given wire grid module in the wire grid array. The metastructure may filter and route several polarization states (e.g., four, two, or all polarization states) to at least one wire grid.

[0069] In some examples, a metastructure can include phase-modulated nanostructures. In some embodiments, a given set of nanostructure elements of a metastructure can include N nanostructures, where N is a positive integer (e.g., 2 to 100). In some embodiments, a given set of nanostructure elements can repeat one or more times within the metastructure (e.g., a periodically repeating set of nanostructure elements). A first nanostructure element in the set can have a phase difference of 2π / N relative to a second nanostructure element in the set. In some embodiments, a first nanostructure element can be adjacent to a second nanostructure element, with the shape of each respective element creating the phase difference.

[0070] The pattern (e.g., periodicity, pixel size / N) of a given set of nanostructure elements can allow wavelength ranges and polarization states to be filtered to target locations. A metastructure can include one or more patterns that can vary across the metastructure. In some examples, the pattern variation can vary based on variations in nanostructure shape (e.g., variations in length, width, length-to-width ratio) and / or rotational orientation (e.g., variations in rotation to change the angle of light polarization) across the metasurface.

[0071] In some examples, a wire grid array can include at least one wire grid module, and a given wire grid module can filter at least one polarization state. The metastructure can guide light and filter it by polarization state. The metastructure can filter light by wavelength range and route it to a given wire grid. In some embodiments, the microlens can include an anti-reflective layer. In some embodiments, the microlens can be embedded over a given sensor pixel. In some embodiments, the metastructure can include a capping layer with a relatively low refractive index to enable optical routing. The wire grid can include a combination of metal and / or metal / semiconductor dielectrics (e.g., metal oxide, nitride, silicon dioxide, etc.).

[0072] FIG. 7 illustrates an example metastructure 700 according to one or more embodiments described herein. In some configurations, one or more aspects of metastructure 700 may be implemented by or in conjunction with a polarization sensor. In some configurations, one or more aspects of metastructure 700 may be implemented by or in conjunction with one or more components of system 100 of FIG. 1 , one or more components of system 200 of FIG. 2 , or any combination thereof. In the illustrated example, metastructure 700 may include metastructure 705. As shown, metastructure 705 may include one or more layers. Although reference is made to routing the polarization state of light throughout the description provided, routing may include routing the polarization state of light and / or the wavelength (e.g., wavelength range) of light.

[0073] In the illustrated example, metastructure 705 can include one or more nanostructured elements. In some embodiments, metastructure 705 can include several repeated nanostructured elements. For example, metastructure 705 can include several nanostructured elements that repeat periodically (e.g., repeat at least once vertically and / or repeat at least once horizontally in the illustrated example metastructure 705).

[0074] As shown, the metastructure 705 can be configured to route at least one of a first polarization state, a second polarization state, a third polarization state, and / or a fourth polarization state. In some examples, the first polarization state can include horizontal polarization, the second polarization state can include vertical polarization, the third polarization state can include diagonal polarization, and the fourth polarization state can include anti-diagonal polarization. In some embodiments, the third polarization state can include right-handed circular polarization, and the fourth polarization state can include left-handed circular polarization. As shown, the metastructure 705 may route and / or focus a first polarization state toward a first target location (e.g., toward a first wire grid and / or a first sensor pixel of a photodetector), route and / or focus a second polarization state toward a second target location (e.g., toward a second wire grid and / or a second sensor pixel of a photodetector), route and / or focus a third polarization state toward a third target location (e.g., toward a third wire grid and / or a third sensor pixel of a photodetector), and / or route and / or focus a fourth polarization state toward a fourth target location (e.g., toward a fourth wire grid and / or a fourth sensor pixel of a photodetector).

[0075] In some examples, a given nanostructured element of metastructure 705 may include one or more dimensions 725. As shown, the dimension 725 of a given nanostructured element may include at least one of a width (e.g., Dx), a length (e.g., Dy), and / or a rotation angle (e.g., θ). In some embodiments, the nanostructured elements of metastructure 705 may be rectangular, cylindrical, triangular, and / or some other shape. In some embodiments, metastructure 705 may depict a top view of a nanostructured element. In some embodiments, metastructure 705 may depict a side view of a nanostructured element.

[0076] In some examples, within a given array element, the magnitude of Dx is not equal to the magnitude of Dy to route horizontally polarized, vertically polarized, diagonally polarized, reverse diagonally polarized, right-handed circularly polarized, and / or left-handed circularly polarized light through the metastructure 700. In some embodiments, within a given array element, the rotation angle can be non-zero (e.g., avoid θ=0 degrees) to route horizontally polarized, vertically polarized, diagonally polarized, reverse diagonally polarized, right-handed circularly polarized, and / or left-handed circularly polarized light through the metastructure 700. In some embodiments, the rotation angle can vary within a given array element to route horizontally polarized, vertically polarized, diagonally polarized, reverse diagonally polarized, right-handed circularly polarized, and / or left-handed circularly polarized light through the metastructure 700. To route horizontally polarized light, vertically polarized light, diagonal polarized light, reverse diagonal polarized light, right-handed circularly polarized light, and / or left-handed circularly polarized light through metastructure 700, the Dx of a first element of a given array of elements can be different from the Dx of a second element of a given array of elements, and / or the Dy of a first element of a given array of elements can be different from the Dy of a second element of a given array of elements.

[0077] In some examples, the nanostructured elements of metastructure 705 can provide a phase shift of up to 2π radians to incident light based on the number of nanostructured elements in a given array of elements (e.g., array of elements 715, array of elements 720). For example, adjacent nanostructures can include a phase difference of 2π / n, where n represents the number of elements in a given array of elements. Thus, if there are four nanostructures in a given array of elements, as shown in 730, the first nanostructured element can induce a phase modulation of 0 radians to the incident light, the second nanostructured element can induce a phase modulation of π / 2 radians to the incident light, the third nanostructured element can induce a phase modulation of π radians to the incident light, and the fourth nanostructured element can induce a phase modulation of 3π / 2 radians to the incident light.

[0078] Based on the systems and methods described herein, the meta-structure 705 can improve the light collection efficiency of a given system (e.g., a polarization sensor). For example, based on the meta-structure 705, the described systems and methods avoid the efficiency limitations of some systems (e.g., the 25% limit in a 2x2 polarization pixel system), and the meta-structure 705 provides improved light collection efficiency for multiple polarization states (e.g., up to or relatively close to 100% light collection efficiency for routing horizontally polarized light, vertically polarized light, diagonal polarized light, reverse diagonal polarized light, right-handed circularly polarized light, and / or left-handed circularly polarized light).

[0079] 8 illustrates an example pattern 800 in accordance with one or more embodiments described herein. In some configurations, one or more aspects of pattern 800 may be implemented by or in conjunction with a polarization sensor. In some configurations, one or more aspects of pattern 800 may be implemented by or in conjunction with one or more components of system 100 of FIG. 1, one or more components of system 200 of FIG. 2, or any combination thereof.

[0080] In the illustrated example, pattern 800 may represent a polarization sensing pattern of a sensor pixel array (e.g., sensor pixel array 120, sensor pixel array 335, sensor pixel array 635). For example, pattern 800 may represent a polarization sensing pattern for sensing vertically polarized light (e.g., V sensor pixels), horizontally polarized light (e.g., H sensor pixels), diagonal polarized light (e.g., D sensor pixels), and left-handed circularly polarized light (e.g., L sensor pixels). For example, a meta structure (e.g., meta structure 320, meta structure 620) may route vertically polarized light to the V sensor pixels of pattern 800, horizontally polarized light to the H sensor pixels of pattern 800, diagonal polarized light to the D sensor pixels of pattern 800, and / or left-handed circularly polarized light to the L sensor pixels of pattern 800.

[0081] As shown, pattern 800 may include a repeating pattern. For example, pattern 800 may include a repeating VHDL, HVLD polarization sensing pattern. In some embodiments, the repeating VHDL, HVLD polarization sensing pattern of pattern 800 may enable a given system to determine the intensity of reverse diagonal and / or right-handed circular polarization based on measuring vertical, horizontal, diagonal, and left-handed circular polarization according to pattern 800 (e.g., detect six polarization states based on measuring four polarization states). For example, pattern 800 may provide full Stokes polarization, i.e., a complete characterization of the polarization state of light, based on measuring vertical, horizontal, diagonal, and left-handed circular polarization. In some examples, four polarization sensor pixels may be used to detect six polarization states based on the following equation:

number

[0082] As shown, the intensity of horizontally polarized light may be measured by one or more H sensor pixels, the intensity of vertically polarized light may be measured by one or more V sensor pixels, the intensity of diagonal polarized light may be measured by one or more D sensor pixels, and the intensity of left-handed circularly polarized light may be measured by one or more L sensor pixels. Also, the intensity of the opposite diagonal polarized light may be determined based on measuring the intensities of the horizontally polarized light, the vertically polarized light, and the diagonal polarized light. And the intensity of the right-handed circularly polarized light may be determined based on measuring the intensities of the horizontally polarized light, the vertically polarized light, and the left-handed circularly polarized light.

[0083] In some examples, based on the polarization states measured according to pattern 800, the following Stokes parameters may be determined:

number

[0084] As shown, S0 may be based on the intensities of horizontally and vertically polarized light, S1 may be based on the intensities of horizontally and vertically polarized light, S2 may be based on the intensity of diagonal polarization and S0, and S3 may be based on the intensity of left-handed circular polarization and S0. In some embodiments, S1, S2, and S3 may represent a three-dimensional vector (S1, S2, S3) in Cartesian coordinates, and S0 may represent the total intensity of a given beam. As shown, the Stokes parameter calculation may provide the indicated degree of linear polarization (DoLP) and / or angle of linear polarization (AoLP).

[0085] In some examples, these six polarization states may be determined based on variations of pattern 800. As shown, pattern 805 may provide polarization sensing for horizontally polarized light (H), vertically polarized light (V), reverse diagonal polarized light (A), and right-hand circularly polarized light (R). For example, pattern 805 may exhibit polarization sensing patterns for sensing horizontally polarized light (e.g., H sensor pixels), vertically polarized light (e.g., V sensor pixels), reverse diagonal polarized light (e.g., A sensor pixels), and right-hand circularly polarized light (e.g., R sensor pixels). For example, a meta-structure (e.g., meta-structure 320, meta-structure 620) may route vertically polarized light to the V sensor pixels of pattern 805, route horizontally polarized light to the H sensor pixels of pattern 805, route reverse diagonal polarized light to the A sensor pixels of pattern 805, and / or route right-hand circularly polarized light to the R sensor pixels of pattern 805.

[0086] As shown, pattern 805 may include a repeating pattern. For example, pattern 805 may include a repeating HVRA, VHAR polarization sensing pattern. In some embodiments, the repeating HVRA, VHAR polarization sensing pattern of pattern 805 may enable a given system to determine the intensity of reverse diagonal polarization and / or right-handed circular polarization based on measuring horizontal polarization, vertical polarization, reverse diagonal polarization, and right-handed circular polarization according to pattern 805 (e.g., detect six polarization states based on measuring four polarization states). For example, pattern 805 may provide full Stokes polarization, i.e., a complete characterization of the polarization state of light, based on measuring horizontal polarization, vertical polarization, reverse diagonal polarization, and right-handed circular polarization. In some examples, four polarization sensor pixels may be used to detect six polarization states based on the equations provided above.

[0087] 9 shows an example pattern 900 according to one or more embodiments described herein. In some configurations, one or more aspects of pattern 900 may be implemented by or in conjunction with a polarization sensor. In some configurations, one or more aspects of pattern 900 may be implemented by or in conjunction with one or more components of system 100 of FIG. 1, one or more components of system 200 of FIG. 2, or any combination thereof.

[0088] When full-Stokes detection is not required, other configurations may be used that not only simplify the sensor pixel configuration but also increase the efficiency rating of a given photodetector. Similar pixels may be placed together to improve signal collection and binning. Depending on the constraints of a given application, the sensor pixel configuration or the configuration of at least a subsection of the photodetector can be linearly or circularly based (e.g., only linearly based polarization sensor pixels, only circularly based polarization sensor pixels). For example, for applications that do not rely on circular polarization, the sensor pixels may be configured for linearly polarized light. Similarly, for applications that do not rely on linear polarization, the sensor pixels may be configured for circularly polarized light. Designing the configuration in line with the application constraints improves the efficiency rating of a given photodetector.

[0089] In the illustrated example, pattern 900 may represent a polarization sensing pattern for a sensor pixel array (e.g., sensor pixel array 120, sensor pixel array 335, sensor pixel array 635). For example, pattern 900 may represent a polarization sensing pattern for sensing vertically polarized light (e.g., V sensor pixels) and horizontally polarized light (e.g., H sensor pixels). In some embodiments, the described systems and methods may include arranging similar pixels together (e.g., VV, HH, VV, etc.) to improve signal collection and / or binning detection.

[0090] 10 illustrates an example pattern 1000 in accordance with one or more embodiments described herein. In some configurations, one or more aspects of pattern 1000 may be implemented by or in conjunction with a polarization sensor. In some configurations, one or more aspects of pattern 1000 may be implemented by or in conjunction with one or more components of system 100 of FIG. 1, one or more components of system 200 of FIG. 2, or any combination thereof.

[0091] In the illustrated example, pattern 1000 may represent a polarization sensing pattern of a sensor pixel array (e.g., sensor pixel array 120, sensor pixel array 335, sensor pixel array 635). Pattern 1000 may be configured to detect circular polarization states. For example, pattern 1000 may represent a polarization sensing pattern for sensing right-handed circularly polarized light (e.g., R sensor pixels) and left-handed circularly polarized light (e.g., L sensor pixels). In some embodiments, the described systems and methods may include arranging similar pixels together (e.g., RR, LL, RR, etc.) to improve signal collection and / or binning detection.

[0092] 11 illustrates an example pattern 1100 in accordance with one or more embodiments described herein. In some configurations, one or more aspects of pattern 1100 may be implemented by or in conjunction with a polarization sensor. In some configurations, one or more aspects of pattern 1100 may be implemented by or in conjunction with one or more components of system 100 of FIG. 1, one or more components of system 200 of FIG. 2, or any combination thereof.

[0093] In the illustrated example, pattern 1100 may represent a polarization sensing pattern for a sensor pixel array (e.g., sensor pixel array 120, sensor pixel array 335, sensor pixel array 635). Pattern 1100 may be configured to detect complete linear polarization states. For example, pattern 1100 may represent a polarization sensing pattern for sensing vertical polarization (e.g., V sensor pixels), horizontal polarization (e.g., H sensor pixels), reverse diagonal polarization (e.g., A sensor pixels), and diagonal polarization (e.g., D sensor pixels). In some embodiments, the described systems and methods may include arranging similar pixels together (e.g., VV, HH, DD, AA, etc.) to improve signal collection and / or binning detection.

[0094] 12 illustrates an example pattern 1200 in accordance with one or more embodiments described herein. In some configurations, one or more aspects of pattern 1200 may be implemented by or in conjunction with a polarization sensor. In some configurations, one or more aspects of pattern 1200 may be implemented by or in conjunction with one or more components of system 100 of FIG. 1, one or more components of system 200 of FIG. 2, or any combination thereof.

[0095] In the illustrated example, pattern 1200 may represent a polarization sensing pattern of a sensor pixel array (e.g., sensor pixel array 120, sensor pixel array 335, sensor pixel array 635). Pattern 1200 may be configured to detect a combination of linear and circular polarization states. For example, pattern 1200 may represent a polarization sensing pattern for sensing vertically polarized light (e.g., V sensor pixels), horizontally polarized light (e.g., H sensor pixels), right-handed circularly polarized light (e.g., R sensor pixels), and left-handed circularly polarized light (e.g., L sensor pixels). In some embodiments, the described systems and methods may include arranging similar pixels together (e.g., VV, HH, LL, RR, etc.) to improve signal collection and / or binning detection.

[0096] Figure 13 shows an example metastructure 1300 in accordance with one or more embodiments described herein. In some examples, metastructure 1300 shows a side view of a metalens that may be part of a thermal imaging system, such as thermal imaging system 100 of Figure 1 and / or thermal imaging system 200 of Figure 2. Metastructure 1300 may be an example of metastructure 320 of Figure 3 and / or metastructure 620 of Figure 6.

[0097] Metastructure 1300 can include at least one nanostructured element. In some embodiments, the top surface of metastructure 1300 can include one or more nanostructured elements. Additionally or alternatively, the bottom surface of metastructure 1300 can include one or more nanostructured elements. In some examples, at least one nanostructured element of metastructure 1300 can be formed based on dry etching and / or wet etching.

[0098] In the illustrated example, metastructure 1300 may include nanostructured elements such as, for example, blazed grating 1305, pillars 1310, binary grating 1315, and holes 1320. In some examples, metastructure 1300 may include one or more patterns of gratings (e.g., a pattern of blazed grating 1305 and / or binary grating 1315). In some embodiments, pillars 1310 may include one or more patterns of pillars. In some embodiments, holes 1320 may include one or more patterns of holes (e.g., of a silicon hole-based metalens).

[0099] 14 shows a flow diagram illustrating an example method 1400 associated with the disclosed system, according to example embodiments described herein. In some configurations, one or more aspects of method 1400 may be implemented by or in conjunction with a polarization sensor. The illustrated method 1400 is just one implementation, and one or more operations of method 1400 may be rearranged, reordered, omitted, and / or otherwise modified; therefore, other embodiments are possible and contemplated.

[0100] At 1405, method 1400 may include routing light of the first polarization to a first wire grid of the wire grid array through a first nanostructure pattern of the metastructure. For example, the first nanostructure pattern of the metastructure can be configured to route light of the first polarization to a first wire grid of the wire grid array.

[0101] At 1410, method 1400 may include routing light of a second polarization to a second wire grid of the wire grid array through a second nanostructure pattern of the metastructure. For example, the second nanostructure pattern of the metastructure can route light of a second polarization, different from the first polarization, to a second wire grid of the wire grid array.

[0102] At 1415, method 1400 may include filtering, with a wire grid array, the light of the first polarization and the light of the second polarization onto sensor pixels of the photodetector. For example, the wire grid array can filter the light of the first polarization and filter the light of the second polarization for one or more sensor pixels of the photodetector.

[0103] 15 shows a flow diagram illustrating an example method 1500 associated with the disclosed system, according to example embodiments described herein. In some configurations, one or more aspects of method 1500 may be implemented by or in conjunction with a polarization sensor. The illustrated method 1500 is just one implementation, and one or more operations of method 1500 may be rearranged, reordered, omitted, and / or otherwise modified; therefore, other embodiments are possible and contemplated.

[0104] At 1505, method 1500 may include routing light of the first polarization to a first wire grid of the wire grid array through a first nanostructure pattern of the metastructure. For example, the first nanostructure pattern of the metastructure can be configured to route light of the first polarization to a first wire grid of the wire grid array.

[0105] At 1510, method 1500 may include routing light of a second polarization to a second wire grid of the wire grid array through a second nanostructure pattern of the metastructure. For example, the second nanostructure pattern of the metastructure can route light of a second polarization, different from the first polarization, to a second wire grid of the wire grid array.

[0106] At 1515, method 1500 may include allowing light of a first polarization to pass through to a first sensor pixel of the photodetector. For example, a first wire grid of the wire grid array may be configured to allow light of the first polarization to pass through to the first sensor pixel of the photodetector and to reflect light of a second polarization away from the first sensor pixel.

[0107] At 1520, method 1500 may include allowing light of the second polarization to pass through to second sensor pixels of the photodetector. For example, a second wire grid of the wire grid array may be configured to allow light of the second polarization to pass through to the second sensor pixels of the photodetector and to reflect light of the first polarization away from the second sensor pixels of the photodetector.

[0108] 16 shows a flow diagram illustrating an example method 1600 associated with the disclosed system, according to example embodiments described herein. In some configurations, one or more aspects of method 1600 may be implemented by or in conjunction with a polarization sensor. The illustrated method 1600 is just one implementation, and one or more operations of method 1600 may be rearranged, reordered, omitted, and / or otherwise modified; therefore, other embodiments are possible and contemplated.

[0109] At 1605, method 1600 may include routing light of a first wavelength (e.g., a first wavelength range) to a first wire grid of the wire grid array through a first nanostructure pattern of the metastructure. For example, the first nanostructure pattern of the metastructure can be configured to route light of the first wavelength to the first wire grid of the wire grid array.

[0110] At 1610, method 1600 may include routing light of a second wavelength (e.g., a second wavelength range) to a second wire grid of the wire grid array via a second nanostructure pattern of the metastructure. For example, the second nanostructure pattern of the metastructure can route light of a second wavelength, different from the first wavelength, to a second wire grid of the wire grid array.

[0111] At 1615, method 1600 may include filtering, with a wire grid array, the light of the first wavelength and the light of the second wavelength to sensor pixels of the photodetector. For example, the wire grid array can filter the light of the first wavelength and filter the light of the second wavelength for one or more sensor pixels of the photodetector.

[0112] Embodiments of the subject matter and operations described herein may be implemented in digital electronic circuitry, or in computer software, firmware, or hardware including the structures disclosed herein and their structural equivalents, or in one or more combinations thereof. Embodiments of the subject matter described herein 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 to control the operation of a data processing apparatus. Alternatively, or in addition, the program instructions may be encoded on an artificially generated propagated signal, such as a machine-generated electrical, optical, or electromagnetic signal, that is generated to encode information for transmission to a suitable receiver apparatus for execution by the data processing apparatus. A computer storage medium may be, or may be included in, a computer-readable storage device, a computer-readable storage substrate, a random-access or serial-access memory array or device, or a combination thereof. Also, while a computer storage medium is not a propagated signal, a computer storage medium may be a source or destination of computer program instructions encoded on an artificially generated propagated signal. A computer storage medium may also be, or may be contained within, one or more separate physical components or media (e.g., multiple CDs, disks, or other storage devices). Additionally, the operations described in this specification may be implemented as operations performed by a data processing apparatus on data stored on one or more computer-readable storage devices or received from other sources.

[0113] While this specification may contain numerous specific implementation details, these implementation details should not be construed as limitations on the scope of the claimed subject matter, but rather as descriptions of features specific to particular embodiments. Specific features described in this specification in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable subcombination. Also, while features may be described above as working in a particular combination and even initially claimed as such, one or more features from a claimed combination may be deleted from the combination in some embodiments, and a claimed combination may be directed to a subcombination or a variation of the subcombination.

[0114] Similarly, while the figures may depict operations in a particular order, this should not be understood as requiring that the operations be performed in the particular order or sequential order depicted, or that all of the depicted operations be performed, to achieve desirable results. In certain situations, multitasking and parallel processing may be advantageous. Also, the separation of various system components in the above-described embodiments should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems may generally be integrated together in a single software product or packaged in multiple software products.

[0115] Accordingly, certain embodiments of the subject matter are described herein. Other embodiments are within the scope of the following claims. In some embodiments, the actions recited in the claims may be performed in a different order and still achieve desirable results. Also, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In certain embodiments, multitasking and parallel processing may be advantageous.

[0116] As will be recognized by those skilled in the art, the innovative concepts described herein are susceptible to modification and variation over a wide range of applications, and therefore, the scope of claimed subject matter should not be limited to any of the specific exemplary teachings described above, but is instead defined by the following claims. [Explanation of symbols]

[0117] 105 Lens 110, 320, 400, 620, 700, 1300 Meta Structure 115, 210, 510 filters 120, 335, 635 sensor pixel array 205, 310, 505, 610 Micro Lenses 305, 605 Global Lens 315, 615 Anti-reflection layer 325, 625 capping layer 330, 630 Wire Grid Array

Claims

1. 1. A polarization sensor, comprising: a metastructure having two or more nanostructured patterns configured to route a polarization state of light toward a photodetector of the polarization sensor, the two or more nanostructured patterns comprising: a first nanostructure pattern configured to route light of a first polarization to a first wire grid of a wire grid array; and a second nanostructure pattern configured to route light of a second polarization different from the first polarization to a second wire grid of the wire grid array; a meta-structure having the wire grid array configured to filter light of the first polarization and light of the second polarization onto sensor pixels of the photodetector; A polarization sensor having

2. the first wire grid of the wire grid array is configured to allow light of the first polarization at a first wavelength to pass through to a first sensor pixel of the photodetector and to reflect or absorb light of the second polarization away from the first sensor pixel of the photodetector; the second wire grid of the wire grid array is configured to allow light of the second polarization at the first wavelength to pass through to second sensor pixels of the photodetector, and to reflect or absorb light of the first polarization away from the second sensor pixels of the photodetector. The polarization sensor of claim 1 .

3. the first nanostructure pattern is configured to route light of a first wavelength to the first wire grid of the wire grid array; the second nanostructure pattern is configured to route light of a second wavelength, different from the first wavelength, to the second wire grid of the wire grid array. The polarization sensor of claim 1 .

4. a third nanostructured pattern of the metastructure configured to route light of a third polarization to a third wire grid of the wire grid array; a fourth nanostructure pattern of the metastructure configured to route light of a fourth polarization different from the third polarization to a fourth wire grid of the wire grid array; The polarization sensor of claim 1 further comprising:

5. the third wire grid of the wire grid array is configured to allow light of the third polarization to pass through to a third sensor pixel of the photodetector and to reflect or absorb light of the fourth polarization away from the third sensor pixel; the fourth wire grid of the wire grid array is configured to allow light of the fourth polarization to pass through to a fourth sensor pixel of the photodetector and to reflect or absorb light of the third polarization away from the fourth sensor pixel of the photodetector.

5. The polarization sensor according to claim 4.

6. the first nanostructured pattern has N nanostructured elements that repeat at least once within the metastructure; the second nanostructured pattern has M nanostructured elements that repeat at least once within the metastructure, the M nanostructured elements being less than, greater than, or equal to the N nanostructured elements; The polarization sensor of claim 1 .

7. a first nanostructured element of the N nanostructured elements is out of phase with a second nanostructured element of the N nanostructured elements; The phase difference is based on the quotient of π and N, The polarization sensor according to claim 6 .

8. a width of a first nanostructured element of the set of repeating nanostructured elements of the metastructure does not match a length of the first nanostructured element; the rotational orientation of the first nanostructured element matches the rotational orientation of a second nanostructured element of the set of repeating nanostructured elements; or a rotational orientation of a third nanostructured element of the set of repeating nanostructured elements does not match a rotational orientation of a fourth nanostructured element of the set of repeating nanostructured elements; The polarization sensor of claim 1 .

9. the width of the third nanostructured element does not match the width of the fourth nanostructured element; or the length of the third nanostructured element does not match the length of the fourth nanostructured element; The polarization sensor of claim 8 .

10. a width of a fifth nanostructured element of the metastructure matches a width of a sixth nanostructured element of the metastructure; a length of the fifth nanostructured element of the metastructure matches a length of the sixth nanostructured element of the metastructure; The polarization sensor of claim 8 .

11. The polarization sensor of claim 1 , wherein light reaches the metastructure by passing through at least one of a global lens, a microlens, or an anti-reflective layer of the polarization sensor.

12. 10. The polarization sensor of claim 1, further comprising a capping layer between the metastructure and the wire grid array, the wire grid array adjacent the photodetector, the capping layer having a refractive index of 3 or less.

13. The polarization sensor of claim 1 , wherein the first polarization or the second polarization comprises horizontal polarization, vertical polarization, diagonal polarization, reverse diagonal polarization, right-handed circular polarization, or left-handed circular polarization.

14. The polarization sensor of claim 1 , wherein the metastructure comprises at least one layer of nanostructured elements, at least one of the layers comprising a relatively high refractive index dielectric material.

15. The polarization sensor of claim 1 , wherein the wire grid array comprises at least one of an array of metal wires and a substrate.

16. 1. A system having at least one polarization sensor, The at least one polarization sensor a metastructure having two or more nanostructured patterns configured to route a polarization state of light toward a photodetector of the polarization sensor, the two or more nanostructured patterns comprising: a first nanostructure pattern configured to route light of a first polarization to a first wire grid of a wire grid array; and a second nanostructure pattern configured to route light of a second polarization different from the first polarization to a second wire grid of the wire grid array; a meta-structure having the wire grid array configured to filter light of the first polarization and light of the second polarization onto sensor pixels of the photodetector; having system.

17. the first wire grid of the wire grid array is configured to allow light of the first polarization at a first wavelength to pass through to a first sensor pixel of the photodetector and to reflect light of the second polarization away from the first sensor pixel of the photodetector; the second wire grid of the wire grid array is configured to allow light of the second polarization at the first wavelength to pass through to second sensor pixels of the photodetector and to reflect light of the first polarization away from the second sensor pixels of the photodetector.

17. The system of claim 16.

18. the first nanostructure pattern is configured to route light of a first wavelength to the first wire grid of the wire grid array; the second nanostructure pattern is configured to route light of a second wavelength, different from the first wavelength, to the second wire grid of the wire grid array.

17. The system of claim 16.

19. 1. A method for routing a polarization state of light to a photodetector of a polarization sensor, comprising: routing light of a first polarization to a first wire grid of the wire grid array via a first nanostructure pattern of the metastructure; routing light of a second polarization different from the first polarization to a second wire grid of the wire grid array via a second nanostructure pattern of the metastructure; filtering the light of the first polarization and the light of the second polarization onto sensor pixels of the photodetector with the wire grid array; How to have that.

20. the first wire grid of the wire grid array is configured to allow light of the first polarization at a first wavelength to pass through to a first sensor pixel of the photodetector and to reflect light of the second polarization away from the first sensor pixel of the photodetector; the second wire grid of the wire grid array is configured to allow light of the second polarization at the first wavelength to pass through to second sensor pixels of the photodetector and to reflect light of the first polarization away from the second sensor pixels of the photodetector.

20. The method of claim 19.

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