Four-dimensional imaging device and method based on binocular polarization sensitive metamaterial lens

Abstract

The invention relates to a four-dimensional imaging device and method based on a binocular polarization sensitive super-structure lens, and the device can comprise a binocular polarization sensitive super-structure lens device which comprises two monocular polarization sensitive super-structure lenses; the monocular polarization sensitive super-structure lens represents a monocular super-structure lens capable of separating different polarization components in incident light; wherein each monocular polarization sensitive metamaterial lens comprises a substrate and a unit structure array distributed on the substrate, the unit structure array comprises a plurality of anisotropic unit structures, and the distance between any two unit structures is smaller than a preset working wavelength; the image sensor is used for receiving the transmission light passing through the binocular polarization sensitive super-structure lens device and generating a target image, and the target image is used for extracting three-dimensional space information and polarization information at the same time. The device is small in size, light in weight and low in complexity, can be conveniently integrated into various application scenes, and can realize depth perception and polarization detection at the same time.

Description

Technical Field

[0001] The present disclosure relates to the field of meta-lens technology, and in particular to a four-dimensional imaging device and method based on binocular polarization-sensitive meta-lens. Background Art

[0002] With the increasing demand for visual information acquisition in modern society, multi-dimensional optical imaging technology has gradually become an important research direction in the field of optics. Traditional two-dimensional imaging technology can only capture the plane image information of an object, and cannot fully describe the material composition, three-dimensional shape, surface morphology and other characteristics of the object. Multi-dimensional imaging technology greatly improves the perception ability of optical imaging systems in complex environments by capturing additional information such as phase, depth, polarization and spectrum.

[0003] At present, traditional multi-dimensional optical imaging systems have several significant defects. First, the complexity of multi-dimensional optical imaging systems is relatively high, and usually requires more optoelectronic components (such as lenses, filters, modulators, mechanical wheels, image sensors, etc.), which makes them bulky, costly, difficult to expand, and low in portability, making it difficult to meet the application requirements of actual complex scenes. Secondly, there is a trade-off between spatial resolution, temporal resolution, and the acquisition of multi-dimensional information (such as depth, polarization) in multi-dimensional optical imaging systems, making them difficult to apply to real-time imaging or high-resolution imaging. In addition, multi-dimensional optical imaging systems can generally only realize the perception of one additional dimension of information based on the acquisition of two-dimensional images. It is still a challenge to integrate multi-dimensional perception functions into a single, compact and efficient platform, which further limits the widespread use of multi-dimensional imaging systems in practical applications.

[0004] With the development of nano-optical technology, metalens has been introduced into the field of multidimensional imaging as a new type of optical element. Metalens is composed of subwavelength unit structures. By designing the geometry and planar distribution of these unit structures, the phase, amplitude and polarization state of light can be controlled with subwavelength resolution. The main technical advantages of metalenses are ultra-thin and ultra-light, compatibility with semiconductor processes, and high design freedom, which makes them have great potential in realizing high-performance and compact multidimensional imaging systems. In recent years, multidimensional imaging technology based on metalens has gradually received attention, but the existing multidimensional imaging technology based on metalens cannot achieve simultaneous perception of polarization and depth information. Summary of the invention

[0005] In view of this, the present disclosure proposes a four-dimensional imaging device, a multi-dimensional information processing method, an electronic device, a storage medium and a computer program product based on a binocular polarization-sensitive meta-lens.

[0006] According to one aspect of the present disclosure, a four-dimensional imaging device based on a binocular polarization-sensitive meta-lens is provided, the device comprising:

[0007] A binocular polarization-sensitive metalens device, comprising two monocular polarization-sensitive metalenses; the monocular polarization-sensitive metalens refers to a monocular metalens capable of separating different polarization components in incident light; wherein each monocular polarization-sensitive metalens comprises a substrate and a unit structure array distributed on the substrate, the unit structure array comprises a plurality of anisotropic unit structures, and a distance between any two unit structures is less than a preset working wavelength;

[0008] An image sensor is used to receive the transmitted light through the binocular polarization-sensitive meta-lens device and generate a target image, wherein the target image is used to simultaneously extract three-dimensional spatial information and polarization information.

[0009] In a possible implementation, the two monocular polarization-sensitive metalenses in the binocular polarization-sensitive metalens device have the same structure, and their optical axes are parallel to each other.

[0010] In a possible implementation, the substrate is fused quartz glass, and the unit structure is an amorphous silicon rectangular column; wherein, the heights of any two unit structures in each monocular polarization-sensitive metalens are the same, and at least one of the lengths, widths, and rotation angles of any two unit structures is different; the height corresponding direction is parallel to the optical axis direction of the monocular polarization-sensitive metalens, the length corresponding direction and the width corresponding direction are both perpendicular to the optical axis direction of the monocular polarization-sensitive metalens, and the rotation angle is the angle between the length corresponding direction of the unit structure and a preset direction.

[0011] In a possible implementation, the rotation angle of the target unit structure satisfies:

[0012]

[0013] Wherein, θ represents the rotation angle of the target unit structure, (x, y) is the position coordinate of the target unit structure, For the phase of left-handed circularly polarized light in the target unit structure, is the phase of right-handed circularly polarized light in the target unit structure; the target unit structure is any unit structure in the unit structure array;

[0014] The length and width of the target unit structure satisfy:

[0015]

[0016] in, is the starting phase of the circularly polarized light incident on the target unit structure, and the starting phase is related to the length and width of the target unit structure.

[0017] In a possible implementation, the phase distribution of left-handed circularly polarized light and right-handed circularly polarized light corresponding to any monocular polarization-sensitive metalens is:

[0018]

[0019] Wherein, (x, y) is the position coordinate of the target unit structure, The phase of left-handed circularly polarized light in the target unit structure, is the phase of the right-handed circularly polarized light in the target unit structure, λ is the preset working wavelength, (x f ,y f ,z f ) is the preset position coordinate of the focus of the monocular polarization-sensitive meta-lens for left-handed circularly polarized light, (x f ,-y f ,z f ) represents the preset position coordinates of the focus of the monocular polarization-sensitive meta-lens for right-handed circularly polarized light.

[0020] In one possible implementation, the target image includes: a first sub-image corresponding to left-handed circularly polarized light, a second sub-image corresponding to right-handed circularly polarized light, a third sub-image corresponding to left-handed circularly polarized light, and a fourth sub-image corresponding to right-handed circularly polarized light; wherein the first sub-image and the second sub-image are generated by the same monocular polarization-sensitive meta-lens, and the third sub-image and the fourth sub-image are generated by the same monocular polarization-sensitive meta-lens.

[0021] In a possible implementation, the device further includes: an aperture and / or a displacement structure;

[0022] Wherein, the aperture is used to control the light transmission range of the light beam entering the binocular polarization-sensitive meta-lens device;

[0023] The displacement structure is used to adjust the distance between the binocular polarization-sensitive meta-lens device and the image sensor.

[0024] According to another aspect of the present disclosure, a multi-dimensional information processing method based on a binocular polarization-sensitive meta-lens is provided, the method comprising:

[0025] Acquire a target image, wherein the target image is a target image of the object to be measured acquired by the above-mentioned four-dimensional imaging device based on binocular polarization-sensitive metalens; the target image includes four sub-images;

[0026] Determine the depth information of the object by calculating the disparity values ​​between the four sub-images;

[0027] The polarization information of the object to be measured is determined by calculating the light intensity difference between the four sub-images.

[0028] According to another aspect of the present disclosure, a multi-dimensional information processing device based on a binocular polarization-sensitive meta-lens is provided, the device comprising:

[0029] An acquisition module, used for acquiring a target image, wherein the target image is a target image of the object under test acquired by the above-mentioned four-dimensional imaging device based on binocular polarization-sensitive metalens; the target image includes four sub-images;

[0030] The calculation module is used to determine the depth information of the object under test by calculating the parallax values ​​between the four sub-images; and to determine the polarization information of the object under test by calculating the light intensity difference between the four sub-images.

[0031] According to another aspect of the present disclosure, an electronic device is provided, comprising: a processor; and a memory for storing processor-executable instructions; wherein the processor is configured to implement the above method when executing the instructions stored in the memory.

[0032] According to another aspect of the present disclosure, a non-volatile computer-readable storage medium is provided, on which computer program instructions are stored, wherein the computer program instructions implement the above method when executed by a processor.

[0033] According to another aspect of the present disclosure, a computer program product is provided, including a computer-readable code, or a non-volatile computer-readable storage medium carrying the computer-readable code. When the computer-readable code runs in a processor of an electronic device, the processor in the electronic device executes the above method.

[0034] In various aspects of the present disclosure, a four-dimensional imaging device based on a binocular polarization-sensitive meta-lens includes: a binocular polarization-sensitive meta-lens device and an image sensor; a binocular polarization-sensitive meta-lens device, including two monocular polarization-sensitive meta-lenses; the monocular polarization-sensitive meta-lens represents a monocular meta-lens capable of separating different polarization components in incident light; wherein each monocular polarization-sensitive meta-lens includes a substrate and a unit structure array distributed on the substrate, the unit structure array includes a plurality of unit structures with anisotropy, and the distance between any two unit structures is less than a preset working wavelength, so that the binocular polarization-sensitive meta-lens device has polarization sensitivity, and at the same time, the binocular polarization-sensitive meta-lens device is small in size and light in weight, and is easy to be integrated into various application scenarios, especially in scenarios with limited space, so as to meet the requirements of high integration and compactness. An image sensor is used to receive the transmitted light passing through the binocular polarization-sensitive meta-lens device and generate a target image, and the target image is used to simultaneously extract three-dimensional spatial information and polarization information. Experimental results show that the four-dimensional imaging device based on the binocular polarization-sensitive metalens can perceive depth information with high precision even when the baseline distance between the two monocular polarization-sensitive metalenses is small, so it can be effectively applied to dynamic perception tasks in complex environments; at the same time, through the sensitivity of the binocular polarization-sensitive metalens device to polarization, the precise separation and detection of different polarization components in the incident light are achieved, which provides an important basis for the analysis of the surface characteristics and physical and chemical properties of the object under test.

[0035] Further features and aspects of the present disclosure will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the disclosure and, together with the description, serve to explain the principles of the disclosure.

[0037] Figure 1 A structural diagram of a four-dimensional imaging device based on a binocular polarization-sensitive meta-lens according to an embodiment of the present disclosure is shown.

[0038] Figure 2 A schematic diagram of a target image according to an embodiment of the present disclosure is shown.

[0039] Figure 3 A schematic structural diagram of a binocular polarization-sensitive meta-lens device according to an embodiment of the present disclosure is shown.

[0040] Figure 4 A structural diagram of a unit structure in a binocular polarization-sensitive meta-lens device according to an embodiment of the present disclosure is shown.

[0041] Figure 5A structural diagram of a four-dimensional imaging device based on a binocular polarization-sensitive meta-lens according to an embodiment of the present disclosure is shown.

[0042] Figure 6 A flowchart of a multi-dimensional information processing method based on a binocular polarization-sensitive meta-lens according to an embodiment of the present disclosure is shown.

[0043] Figure 7 A structural diagram of a multi-dimensional information processing device based on a binocular polarization-sensitive meta-lens according to an embodiment of the present disclosure is shown.

[0044] Figure 8 A block diagram of an electronic device 1900 according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0045] Various exemplary embodiments, features and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0046] References to "one embodiment" or "some embodiments" etc. described in this specification mean that one or more embodiments of the present disclosure include specific features, structures or characteristics described in conjunction with the embodiment. Thus, the phrases "exemplary", "in one embodiment", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0047] In the present disclosure, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: including the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or plural.

[0048] In addition, in order to better illustrate the present disclosure, numerous specific details are given in the following specific embodiments. It should be understood by those skilled in the art that the present disclosure can also be implemented without certain specific details. In some examples, methods, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the main purpose of the present disclosure.

[0049] In multi-dimensional imaging technology, polarization and depth are two important information dimensions. The polarization state of light is of great significance in analyzing the material properties, surface roughness and microstructure of an object; in complex scenes, polarization information is crucial to improving the accuracy of target detection and recognition. Depth information can help the imaging system understand the three-dimensional spatial structure of an object, support target positioning and scene reconstruction in complex environments, and use polarization information and depth information to assist traditional imaging, which is conducive to improving the applicability and robustness of the imaging system in complex environments, reducing the complexity of post-processing algorithms, and the comprehensive analysis of multi-dimensional information may also generate new useful information. In related technologies, when obtaining depth information and polarization information at the same time, multiple complex optical devices are often required to cooperate, resulting in increased complexity and cost of the imaging system; and the multi-dimensional imaging technology based on meta-lens cannot achieve simultaneous perception of polarization and depth information. For example, polarization perception or depth imaging based on a single meta-lens can only achieve three-dimensional imaging on the basis of a plane image.

[0050] The disclosed embodiment proposes a four-dimensional imaging solution based on a binocular polarization-sensitive metalens. By utilizing the unique advantages of the metalens and combining it with the binocular polarization-sensitive metalens configuration, the simultaneous acquisition of three-dimensional spatial information and polarization information of the object under test is achieved, so as to meet the demand for efficient acquisition of multi-dimensional information in complex application scenarios and solve the problems of large size, high complexity, high cost and low imaging dimension of existing multi-dimensional imaging systems.

[0051] Figure 1 FIG. 1 shows a structural diagram of a four-dimensional imaging device based on a binocular polarization-sensitive meta-lens according to an embodiment of the present disclosure. Figure 1 As shown, the device may include: a binocular polarization-sensitive meta-lens device, including two monocular polarization-sensitive meta-lenses; the monocular polarization-sensitive meta-lens represents a monocular meta-lens capable of separating different polarization components in incident light; wherein each monocular polarization-sensitive meta-lens includes a substrate and a unit structure array distributed on the substrate, the unit structure array includes a plurality of anisotropic unit structures, and the distance between any two unit structures is less than a preset working wavelength; an image sensor, used to receive the transmitted light passing through the binocular polarization-sensitive meta-lens device and generate a target image, wherein the target image is used to simultaneously extract three-dimensional spatial information and polarization information.

[0052] The two monocular polarization-sensitive meta-lenses are located in the same plane and have the same focal length, so that the image sensor can simultaneously image the transmitted light passing through the two monocular polarization-sensitive meta-lenses, and the generated target image includes the imaging area corresponding to each monocular polarization-sensitive meta-lens. The baseline distance between the two monocular polarization-sensitive meta-lenses can be set according to demand, and the baseline distance is the distance between the centers of the two monocular polarization-sensitive meta-lenses. For example, the baseline distance can be designed to be as short as possible on the basis of keeping the imaging area corresponding to each monocular polarization-sensitive meta-lens clear and complete, so as to make the size of the binocular polarization-sensitive meta-lens device as small as possible.

[0053] In one possible implementation, the two monocular polarization-sensitive meta-lenses in the binocular polarization-sensitive meta-lens device have the same structure, and the optical axes are parallel to each other. In this way, two monocular polarization-sensitive meta-lenses with exactly the same structure are combined to form a binocular polarization-sensitive meta-lens device, and in the target image generated by the image sensor, the image size in the imaging area corresponding to each monocular polarization-sensitive meta-lens is the same, thereby reducing the difficulty of subsequent image processing and improving the efficiency and accuracy of image processing. Exemplarily, when preparing a binocular polarization-sensitive meta-lens device, a high-precision semiconductor micro-nano processing technology can be used to ensure the consistency of the two monocular polarization-sensitive meta-lenses, the parallel optical axes, and the baseline distance of the two monocular polarization-sensitive meta-lenses is the same as the design value or the error is small.

[0054] Exemplarily, two monocular polarization-sensitive metalenses are symmetrically distributed about the center of the binocular polarization-sensitive metalens device; thus, the imaging in the imaging areas corresponding to the two monocular polarization-sensitive metalenses is symmetrically distributed, further reducing the difficulty of subsequent image processing and improving the efficiency and accuracy of image processing.

[0055] Exemplarily, the image sensor and the binocular polarization-sensitive meta-lens device are spaced apart, and the distance of the spacing can be set as required. Among them, each monocular polarization-sensitive meta-lens can converge different polarized light to different focal points respectively, so that after the incident light of the object to be measured in the external environment is transmitted through the binocular polarization-sensitive meta-lens device, the transmitted light can generate four independent sub-images on the image sensor, and each sub-image has a complete image of the object to be measured. Furthermore, by analyzing and processing the target image generated by the image sensor, multi-dimensional information such as three-dimensional spatial information (including depth information and two-dimensional position information) and polarization information of the object to be measured can be extracted, wherein the specific analysis and processing process can be referred to the relevant description below.

[0056] In one possible implementation, the target image includes: a first sub-image corresponding to left-handed circularly polarized light, a second sub-image corresponding to right-handed circularly polarized light, a third sub-image corresponding to left-handed circularly polarized light, and a fourth sub-image corresponding to right-handed circularly polarized light; wherein the first sub-image and the second sub-image are generated by the same monocular polarization-sensitive meta-lens, and the third sub-image and the fourth sub-image are generated by the same monocular polarization-sensitive meta-lens. Figure 2 A schematic diagram of a target image according to an embodiment of the present disclosure is shown as follows: Figure 2 As shown, based on the direction of the incident light, the first sub-image and the second sub-image are located in the imaging area corresponding to the monocular polarization-sensitive meta-lens on the left, and the third sub-image and the fourth sub-image are located in the imaging area corresponding to the monocular polarization-sensitive meta-lens on the right; wherein the first sub-image and the third sub-image are both imaged by left-handed circularly polarized light, and the second sub-image and the fourth sub-image are both imaged by right-handed circularly polarized light; in this way, each monocular polarization-sensitive meta-lens can separate the left-handed circularly polarized light and the right-handed circularly polarized light in the incident light, and respectively converge them to different focal points to generate a sub-image corresponding to the left-handed circularly polarized light and a sub-image corresponding to the right-handed circularly polarized light, thereby forming a target image including four sub-images.

[0057] For example, the shape of the unit structure array, the arrangement of each unit structure in the unit structure array, the number of unit structures, the material of the substrate, etc. in any monocular polarization-sensitive meta-lens can be set as required, and there is no limitation on this; for example, the number of unit structures contained in the unit structure array can be as large as possible on the basis of ensuring that the distance between any two unit structures is less than the preset working wavelength, thereby improving the imaging effect. Among them, the working wavelength represents the specific wavelength or light beam within the wavelength range that the binocular polarization-sensitive meta-lens device can effectively focus or regulate. The working wavelength determines the applicable scope of the binocular polarization-sensitive meta-lens device. The working wavelength is usually closely related to the structural design of the binocular polarization-sensitive meta-lens device. Different structural designs can make the binocular polarization-sensitive meta-lens device work at different working wavelengths. Therefore, the appropriate working wavelength can be pre-determined according to the specific application requirements, and then based on the preset working wavelength, the structural parameters (such as width, length, height, angle, etc.) of the binocular polarization-sensitive meta-lens device are determined, so as to further prepare the binocular polarization-sensitive meta-lens device. Exemplarily, the preset working wavelength may be a certain wavelength or a certain wavelength range, for example, a wavelength range such as a visible light band, an ultraviolet band or an infrared band.

[0058] Exemplarily, the shape, size, and material of each unit structure can be set according to requirements; for example, the shape of each unit structure can be rectangular, cross-shaped, cylindrical, etc. In a possible implementation, the substrate is fused silica glass, and the unit structure is an amorphous silicon rectangular column; wherein, the height of any two unit structures in each monocular polarization-sensitive metalens is the same, and at least one of the length, width, and rotation angle of any two unit structures is different; the height corresponding direction is parallel to the optical axis direction of the monocular polarization-sensitive metalens, the length corresponding direction and the width corresponding direction are both perpendicular to the optical axis direction of the monocular polarization-sensitive metalens, and the rotation angle is the angle between the length corresponding direction of the unit structure and the preset direction. In this way, the height of any two unit structures is the same, and the unit structures distributed in a two-dimensional array on the substrate constitute a monocular polarization-sensitive metalens; at the same time, at least one of the length, width, and rotation angle of any two unit structures is different, and the composed monocular polarization-sensitive metalens can provide different phase delays for left-handed circularly polarized light and right-handed circularly polarized light, thereby separating different polarization components in the incident light.

[0059] Figure 3 FIG. 2 is a schematic diagram showing the structure of a binocular polarization-sensitive meta-lens device according to an embodiment of the present disclosure. Figure 3 As shown, it is a front view (i.e., a view along the direction of incident light) of a binocular polarization-sensitive metalens device, wherein the binocular polarization-sensitive metalens device comprises a substrate made of fused silica glass material, on which two monocular polarization-sensitive meta-lenses with identical structures are symmetrically distributed, wherein each monocular polarization-sensitive meta-lens comprises a plurality of amorphous silicon rectangular columns (i.e., a unit structure), and the length, width, and rotation angle of each crystalline silicon rectangular column are not identical. For each monocular polarization-sensitive meta-lens, an independent coordinate system is established, wherein the coordinate system of any monocular polarization-sensitive meta-lens takes the center of the monocular polarization-sensitive meta-lens as the origin, the optical axis direction as the Z axis, the center line of the two monocular polarization-sensitive meta-lenses as the X axis, and the vertical direction of the center line of the two monocular polarization-sensitive meta-lenses as the Y axis, and the plane where the X axis and the Y axis are located is parallel to the plane where the substrate is located.

[0060] Exemplarily, the substrate portion corresponding to each monocular polarization-sensitive metalens can be divided into a plurality of substrate units of equal size and shape; wherein each substrate unit corresponds to a unit structure, and taking the unit structure as an amorphous silicon rectangular column as an example, for a substrate unit at any position, after designing the length, width, height, and angle corresponding to the position, a unit structure fixed to the substrate unit can be prepared; wherein the height corresponding to each position is the same, and the length, width, and angle corresponding to each position are not exactly the same. Figure 4 A structural diagram of a unit structure in a binocular polarization-sensitive meta-lens device according to an embodiment of the present disclosure is shown as follows: Figure 4 As shown, for any monocular polarization-sensitive metalens, the substrate unit is a hexagonal prism, and the unit structure is an amorphous silicon rectangular column, which is fixed on the hexagonal prism in a form perpendicular to the substrate, wherein the direction corresponding to the height (H) of the amorphous silicon rectangular column is consistent with the direction of the Z axis of the coordinate system of the monocular polarization-sensitive metalens, the lengths of the two intersecting sides of the rectangle in the front view of the amorphous silicon rectangular column are the length (Lx) and the width (Ly), and the angle between the length corresponding direction of the amorphous silicon rectangular column and the positive direction of the X axis (i.e., the preset direction) of the coordinate system of the monocular polarization-sensitive metalens is the rotation angle θ.

[0061] Taking the unit structure as an amorphous silicon rectangular column as an example, the length and width of the amorphous silicon rectangular column determine the transmission amplitude and starting phase of the unit structure for the incident circularly polarized light. The rotation angle of the amorphous silicon rectangular column determines the geometric phase of the unit structure for the incident circularly polarized light; the geometric phase can provide different phase delays for left-handed circularly polarized light and right-handed circularly polarized light, thereby achieving the focusing of light with different polarizations. By designing the rotation angle of each unit structure, the two polarized lights, left-handed and right-handed, can be focused to different positions on the imaging plane of the image sensor.

[0062] In a possible implementation, the rotation angle of the target unit structure satisfies:

[0063]

[0064] Wherein, θ represents the rotation angle of the target unit structure, (x, y) is the position coordinate of the target unit structure, is the phase (i.e. geometric phase) of the left-handed circularly polarized light in the target unit structure, is the phase of right-handed circularly polarized light in the target unit structure; the target unit structure is any unit structure in the unit structure array;

[0065] The length and width of the target unit structure satisfy:

[0066]

[0067] in, is the starting phase of the circularly polarized light incident on the target unit structure, and the starting phase is related to the length and width of the target unit structure.

[0068] In this way, for the unit structure at any position, after determining the phases of the left-handed circularly polarized light and the right-handed circularly polarized light in the unit structure, the rotation angle of the unit structure and the starting phase of the unit structure can be obtained. Furthermore, the length and width of the unit structure can be determined based on the starting phase, and the height of the unit structure can be set in advance. When the length, width, height, and rotation angle of the unit structure are designed, an amorphous silicon rectangular column can be prepared, thereby completing the design and preparation of the unit structure at this position.

[0069] Since the meta-lens is composed of sub-wavelength unit structures, where the sub-wavelength unit structure refers to a structure whose structural parameters are equivalent to or smaller than the working wavelength; taking the unit structure as an amorphous silicon rectangular column as an example, the length, width, and height of the amorphous silicon rectangular column need to be less than the preset working wavelength. Therefore, after the working wavelength is preset, a specific value less than the preset working wavelength can be used as the height of each unit structure, and then, after the starting phase of the unit structure is obtained, the length and width of each unit structure can be determined within a specific range less than the preset working wavelength. For example, the preset working wavelength is 500nm, and the values ​​of the length and width of the unit structure can be optimized and calculated within the range of 50 to 450nm to obtain the corresponding transmission amplitude and starting phase of different values, and then the values ​​of the length and width that meet the starting phase can be selected to determine the length and width of each unit structure; illustratively, when the starting phase is met, the values ​​of the length and width with higher transmission amplitude can be selected to improve the imaging effect.

[0070] In a possible implementation, the phase distribution of left-handed circularly polarized light and right-handed circularly polarized light corresponding to any monocular polarization-sensitive metalens is:

[0071]

[0072] Wherein, (x, y) is the position coordinate of the target unit structure, The phase of left-handed circularly polarized light in the target unit structure, is the phase of the right-handed circularly polarized light in the target unit structure, λ is the preset working wavelength, (x f ,y f ,z f ) is the preset position coordinate of the focus of the monocular polarization-sensitive meta-lens for left-handed circularly polarized light, (x f ,-y f ,z f ) represents the preset position coordinates of the focus of the monocular polarization-sensitive meta-lens for right-handed circularly polarized light.

[0073] Exemplarily, in the case where the working wavelength and the position coordinates of the focus are predetermined, for any monocular polarization-sensitive metalens, the phases of the unit structures of left-handed circularly polarized light and right-handed circularly polarized light at different positions are determined, thereby obtaining a phase distribution. In this way, the monocular polarization-sensitive metalens can respectively give independent phase distributions to the left-handed circularly polarized light and the right-handed circularly polarized light: after determining the phase distribution, based on the phase distribution, the starting phase corresponding to the unit structures at different positions of the circularly polarized light incident thereon is determined, and then, by adjusting the length and width of the unit structure until the starting phase is reached, the length and width at this time are used as the length and width of the unit structure at this position. As an example, for a specific material, a specific shape, and a specific position, the starting phases of different structural parameters of the unit structure at a preset working wavelength can be numerically simulated or experimentally measured. For example, the width can be kept unchanged, and the length and / or width can be adjusted, thereby obtaining the length and width of the unit structure corresponding to the starting phase at the preset working wavelength. In this way, for each working wavelength and focus, the starting phase of the incident light of the working wavelength in each unit structure and the rotation angle of each unit structure can be determined, and then the length and width of the unit structure are configured by the starting phase to obtain the structural parameters of each unit structure.

[0074] The four-dimensional imaging device based on binocular polarization-sensitive meta-lens in the disclosed embodiment includes: a binocular polarization-sensitive meta-lens device and an image sensor; a binocular polarization-sensitive meta-lens device, including two monocular polarization-sensitive meta-lenses; the monocular polarization-sensitive meta-lens represents a monocular meta-lens capable of separating different polarization components (such as left-handed circularly polarized light and right-handed circularly polarized light) in incident light; wherein each monocular polarization-sensitive meta-lens includes a substrate and a unit structure array distributed on the substrate, the unit structure array includes a plurality of unit structures with anisotropy, and the distance between any two unit structures is less than a preset working wavelength, so that the binocular polarization-sensitive meta-lens device has polarization sensitivity, and at the same time, the binocular polarization-sensitive meta-lens device is small in size and light in weight, and is easy to be integrated into various application scenarios, especially in scenarios with limited space, so as to meet the requirements of high integration and compactness. An image sensor is used to receive the transmitted light through the binocular polarization-sensitive meta-lens device and generate a target image, and the target image is used to simultaneously extract three-dimensional spatial information and polarization information. Experimental results show that the average relative error of the four-dimensional imaging device based on the binocular polarization-sensitive metalens in 3D reconstruction is less than 5%. Even when the baseline distance between the two monocular polarization-sensitive metalenses is small, it can perceive depth information with high precision, thus being effectively applicable to dynamic perception tasks in complex environments. At the same time, through the sensitivity of the binocular polarization-sensitive metalens device to polarization, the precise separation and detection of different polarization components in the incident light are achieved, providing an important basis for the analysis of the surface characteristics and physical and chemical properties of the object being measured.

[0075] Figure 5 FIG. 1 shows a structural diagram of a four-dimensional imaging device based on a binocular polarization-sensitive meta-lens according to an embodiment of the present disclosure. Figure 5 As shown, the device may include: a binocular polarization-sensitive meta-lens device, an image sensor, an aperture and / or a displacement structure; wherein the aperture is used to control the light transmission range of the light beam entering the binocular polarization-sensitive meta-lens device; and the displacement structure is used to adjust the distance between the binocular polarization-sensitive meta-lens device and the image sensor.

[0076] Exemplarily, the position of the aperture can be adjusted to optimize the depth of field of the optical system and reduce the influence of aberrations, ensuring that only the valid light beam from the object under test enters the binocular polarization-sensitive meta-lens device.

[0077] Wherein, the binocular polarization-sensitive meta-lens device, the image sensor and the above Figure 1 The binocular polarization-sensitive meta-lens device and image sensor are the same and will not be elaborated here.

[0078] Understandably, Figure 5 The device shown in the figure can be equipped with other components as needed, for example, Figure 5 The device housing is shown.

[0079] In the disclosed embodiment, based on the configuration of a binocular polarization-sensitive meta-lens device and an image sensor, the light transmission range of the light beam entering the binocular polarization-sensitive meta-lens device is controlled by an aperture, thereby improving the imaging quality; the relative position between the binocular polarization-sensitive meta-lens device and the image sensor is adjusted by a displacement structure to achieve optimal optical alignment and focus control to adapt to the imaging requirements of different scenes and working distances.

[0080] The disclosed embodiment also provides a multi-dimensional information processing method based on binocular polarization-sensitive meta-lens. Exemplarily, the method can be executed by a processor, for example, a central processing unit of an electronic device, or a server or server cluster.

[0081] Figure 6 A flowchart of a multi-dimensional information processing method based on a binocular polarization-sensitive meta-lens according to an embodiment of the present disclosure is shown. Figure 6 As shown, the method may include:

[0082] Step 601: Acquire a target image, wherein the target image is a target image of the object under test acquired by the above-mentioned four-dimensional imaging device based on binocular polarization-sensitive metalens; the target image includes four sub-images.

[0083] For example, the target image can be Figure 1 or Figure 5 Images captured by the four-dimensional imaging device based on binocular polarization-sensitive metalens shown in .

[0084] Exemplarily, the processed four-dimensional imaging device of the binocular polarization-sensitive metalens and the object to be measured can be placed in the experimental light path, and a light source is used to illuminate the object to be measured, so that the object emits incident light of a preset working wavelength of the binocular polarization-sensitive metalens. After the incident light is transmitted through the binocular polarization-sensitive metalens, the transmitted light is imaged in the image sensor to generate a target image.

[0085] In a possible implementation, the target image may be preprocessed; for example, the acquired target image may be subjected to denoising and correction, etc., for subsequent depth reconstruction and polarization detection. As an example, the target image may be first denoised as a whole by Gaussian filtering, and then geometric distortion correction may be performed in combination with calibration parameters.

[0086] Step 602: Determine the depth information of the object by calculating the disparity values ​​between the four sub-images.

[0087] The disparity value represents the position difference between corresponding points on the sub-images of the two monocular polarization-sensitive meta-lenses corresponding to the same polarization state. Exemplarily, the disparity value can be calculated using an existing stereo matching algorithm.

[0088] Exemplarily, for sub-images corresponding to the same polarization state of two monocular polarization-sensitive metalenses, feature point matching is performed in the same horizontal direction in the two sub-images to determine the corresponding feature points in the two sub-images, and then the parallax value is determined based on the coordinate values ​​of the two feature points.

[0089] For example, the above Figure 2 Taking the target image shown as an example, for the sub-images corresponding to the same polarization state of two monocular polarization-sensitive meta-lenses, the disparity values ​​of the two sub-images are calculated; for example, based on the sub-images corresponding to left-handed circular polarization of two monocular polarization-sensitive meta-lenses (i.e., the first sub-image and the third sub-image), the disparity value between the two sub-images can be calculated, so that the depth of the three-dimensional space can be calculated.

[0090] In this way, by analyzing the disparity between different sub-images in the target image, the depth information of the object under test can be reconstructed.

[0091] Step 603: Determine the polarization information of the object to be measured by calculating the light intensity difference between the four sub-images.

[0092] For example, the difference in light intensity of corresponding pixel points in two sub-images in the imaging area corresponding to the monocular polarization-sensitive meta-lens can be calculated, and the difference in light intensity is the difference in polarization state of the corresponding pixel points.

[0093] For example, the above Figure 2 Taking the target image shown as an example, for the two sub-images in the imaging area corresponding to any monocular polarization-sensitive meta-lens, the light intensity difference in the two sub-images can be calculated to determine the components of each circularly polarized light in the incident light. For example, the light intensity difference between the first sub-image and the third sub-image can be calculated. If the light intensity of the left-handed circular polarization in the first sub-image is greater than the light intensity of the right-handed circular polarization in the third sub-image, it means that the component of the left-handed circular polarization in the incident light is greater than the component of the right-handed circular polarization.

[0094] In this way, by comparing the light intensity differences between different sub-images, the polarization state of the surface of the measured object can be determined, thereby realizing polarization detection. The polarization information can be further used to analyze the surface characteristics of the measured object to obtain the physical and chemical properties such as the material composition of the measured object.

[0095] In the disclosed embodiment, by processing the target image obtained from the binocular polarization-sensitive metalens four-dimensional imaging device, the three-dimensional reconstruction of the object under test and the synchronous acquisition and comprehensive analysis of multi-dimensional information such as polarization information are realized, which greatly improves the multi-dimensionality and information richness of the imaging. Furthermore, the material composition, three-dimensional shape, surface morphology and other characteristics of the object under test can be further determined based on the multi-dimensional information to meet different needs.

[0096] Based on the same inventive concept of the above method embodiments, the embodiments of the present disclosure also provide a multi-dimensional information processing device based on binocular polarization-sensitive meta-lens, which can be used to execute the technical solution described in the above method embodiments.

[0097] Figure 7 A structural diagram of a multi-dimensional information processing device based on a binocular polarization-sensitive meta-lens according to an embodiment of the present disclosure is shown. Figure 7 As shown, the device may include:

[0098] An acquisition module 701 is used to acquire a target image, wherein the target image is a target image of the object under test acquired by the above-mentioned four-dimensional imaging device based on binocular polarization-sensitive metalens; the target image includes four sub-images;

[0099] The calculation module 702 is used to determine the depth information of the object under test by calculating the parallax values ​​between the four sub-images; and to determine the polarization information of the object under test by calculating the light intensity difference between the four sub-images.

[0100] In the disclosed embodiment, by processing the target image obtained from the binocular polarization-sensitive metalens four-dimensional imaging device, the three-dimensional reconstruction of the object under test and the synchronous acquisition and comprehensive analysis of multi-dimensional information such as polarization information are realized, which greatly improves the multi-dimensionality and information richness of the imaging. Furthermore, the material composition, three-dimensional shape, surface morphology and other characteristics of the object under test can be further determined based on the multi-dimensional information to meet different needs.

[0101] In some embodiments, the functions or modules included in the device provided by the embodiments of the present disclosure can be used to execute the method described in the above method embodiments. The specific implementation can refer to the description of the above method embodiments, and for the sake of brevity, it will not be repeated here.

[0102] The embodiment of the present disclosure also provides a computer-readable storage medium on which computer program instructions are stored, and the computer program instructions implement the above method when executed by a processor. The computer-readable storage medium can be a volatile or non-volatile computer-readable storage medium.

[0103] An embodiment of the present disclosure further proposes an electronic device, comprising: a processor; and a memory for storing instructions executable by the processor; wherein the processor is configured to implement the above method when executing the instructions stored in the memory.

[0104] The embodiments of the present disclosure also provide a computer program product, including a computer-readable code, or a non-volatile computer-readable storage medium carrying the computer-readable code. When the computer-readable code runs in a processor of an electronic device, the processor in the electronic device executes the above method.

[0105] Figure 8 1 is a block diagram of an electronic device 1900 according to an embodiment of the present disclosure. For example, the electronic device 1900 may be provided as a server or a terminal device. Figure 8 , the electronic device 1900 includes a processing component 1922, which further includes one or more processors, and a memory resource represented by a memory 1932 for storing instructions that can be executed by the processing component 1922, such as an application. The application stored in the memory 1932 may include one or more modules, each corresponding to a set of instructions. In addition, the processing component 1922 is configured to execute instructions to perform the above method.

[0106] The electronic device 1900 may also include a power supply component 1926 configured to perform power management of the electronic device 1900, a wired or wireless network interface 1950 configured to connect the electronic device 1900 to a network, and an input / output interface 1958 (I / O interface). The electronic device 1900 may operate based on an operating system stored in the memory 1932, such as Windows Server 2003. TM , Mac OS X TM , Unix TM ,Linux TM , FreeBSD TM or similar.

[0107] In an exemplary embodiment, a non-volatile computer-readable storage medium is also provided, such as a memory 1932 including computer program instructions, which can be executed by the processing component 1922 of the electronic device 1900 to perform the above method.

[0108] The present disclosure may be a system, a method and / or a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for causing a processor to implement various aspects of the present disclosure.

[0109] A computer-readable storage medium may be a tangible device that can hold and store instructions used by an instruction execution device. A computer-readable storage medium may be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. More specific examples of computer-readable storage media (a non-exhaustive list) include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disk read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanical encoding device, such as a punch card or a raised structure in a groove on which instructions are stored, and any suitable combination of the foregoing. As used herein, a computer-readable storage medium is not to be interpreted as a transient signal per se, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., a light pulse through a fiber optic cable), or an electrical signal transmitted through a wire.

[0110] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to each computing / processing device, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network can include copper transmission cables, optical fiber transmissions, wireless transmissions, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in the computer-readable storage medium in each computing / processing device.

[0111] The computer program instructions for performing the operation of the present disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-related instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages, such as Smalltalk, C++, etc., and conventional procedural programming languages, such as "C" language or similar programming languages. Computer-readable program instructions may be executed completely on a user's computer, partially on a user's computer, as an independent software package, partially on a user's computer, partially on a remote computer, or completely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., using an Internet service provider to connect via the Internet). In some embodiments, an electronic circuit, such as a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA), may be customized by utilizing the state information of the computer-readable program instructions, and the electronic circuit may execute the computer-readable program instructions, thereby realizing various aspects of the present disclosure.

[0112] Various aspects of the present disclosure are described herein with reference to the flowcharts and / or block diagrams of the methods, devices (systems) and computer program products according to the embodiments of the present disclosure. It should be understood that each box in the flowchart and / or block diagram and the combination of each box in the flowchart and / or block diagram can be implemented by computer-readable program instructions.

[0113] These computer-readable program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, thereby producing a machine, so that when these instructions are executed by the processor of the computer or other programmable data processing device, a device that implements the functions / actions specified in one or more boxes in the flowchart and / or block diagram is generated. These computer-readable program instructions can also be stored in a computer-readable storage medium, and these instructions cause the computer, programmable data processing device, and / or other equipment to work in a specific manner, so that the computer-readable medium storing the instructions includes a manufactured product, which includes instructions for implementing various aspects of the functions / actions specified in one or more boxes in the flowchart and / or block diagram.

[0114] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device so that a series of operating steps are performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby causing the instructions executed on the computer, other programmable data processing apparatus, or other device to implement the functions / actions specified in one or more boxes in the flowchart and / or block diagram.

[0115] The flow chart and block diagram in the accompanying drawings show the possible architecture, function and operation of the system, method and computer program product according to multiple embodiments of the present disclosure. In this regard, each square box in the flow chart or block diagram can represent a part of a module, program segment or instruction, and a part of the module, program segment or instruction includes one or more executable instructions for realizing the specified logical function. In some alternative implementations, the function marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two continuous square boxes can actually be executed substantially in parallel, and they can sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs the specified function or action, or can be implemented with a combination of special hardware and computer instructions.

[0116] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A four-dimensional imaging device based on binocular polarization-sensitive meta-lens, characterized in that: The device comprises: A binocular polarization-sensitive metalens device, comprising two monocular polarization-sensitive metalenses; the monocular polarization-sensitive metalens refers to a monocular metalens capable of separating different polarization components in incident light; wherein each monocular polarization-sensitive metalens comprises a substrate and a unit structure array distributed on the substrate, the unit structure array comprises a plurality of anisotropic unit structures, and a distance between any two unit structures is less than a preset working wavelength; An image sensor is used to receive the transmitted light through the binocular polarization-sensitive meta-lens device and generate a target image, wherein the target image is used to simultaneously extract three-dimensional spatial information and polarization information.

2. The device according to claim 1, characterized in that The two monocular polarization-sensitive meta-lenses in the binocular polarization-sensitive meta-lens device have the same structure, and their optical axes are parallel to each other.

3. The device according to claim 1, characterized in that The substrate is fused quartz glass, and the unit structure is an amorphous silicon rectangular column; wherein, the heights of any two unit structures in each monocular polarization-sensitive metalens are the same, and at least one of the lengths, widths, and rotation angles of any two unit structures is different; the height corresponding direction is parallel to the optical axis direction of the monocular polarization-sensitive metalens, the length corresponding direction and the width corresponding direction are both perpendicular to the optical axis direction of the monocular polarization-sensitive metalens, and the rotation angle is the angle between the length corresponding direction of the unit structure and a preset direction.

4. The device according to claim 3, characterized in that The corners of the target unit structure satisfy: Wherein, θ represents the rotation angle of the target unit structure, (x, y) is the position coordinate of the target unit structure, For the phase of left-handed circularly polarized light in the target unit structure, is the phase of right-handed circularly polarized light in the target unit structure; the target unit structure is any unit structure in the unit structure array; The length and width of the target unit structure satisfy: in, is the starting phase of the circularly polarized light incident on the target unit structure, and the starting phase is related to the length and width of the target unit structure.

5. The device according to claim 4, characterized in that The phase distribution of left-handed circularly polarized light and right-handed circularly polarized light corresponding to any monocular polarization-sensitive metalens is: Wherein, (x, y) is the position coordinate of the target unit structure, The phase of left-handed circularly polarized light in the target unit structure, is the phase of the right-handed circularly polarized light in the target unit structure, λ is the preset working wavelength, (x f ,y f ,z f ) is the preset position coordinate of the focus of the monocular polarization-sensitive meta-lens for left-handed circularly polarized light, (x f ,-y f ,z f ) represents the preset position coordinates of the focus of the monocular polarization-sensitive meta-lens for right-handed circularly polarized light.

6. The device according to claim 1, characterized in that The target image includes: a first sub-image corresponding to left-handed circularly polarized light, a second sub-image corresponding to right-handed circularly polarized light, a third sub-image corresponding to left-handed circularly polarized light, and a fourth sub-image corresponding to right-handed circularly polarized light; wherein the first sub-image and the second sub-image are generated by the same monocular polarization-sensitive meta-lens, and the third sub-image and the fourth sub-image are generated by the same monocular polarization-sensitive meta-lens.

7. The device according to claim 1, characterized in that The device further comprises: an aperture and / or a displacement structure; Wherein, the aperture is used to control the light transmission range of the light beam entering the binocular polarization-sensitive meta-lens device; The displacement structure is used to adjust the distance between the binocular polarization-sensitive meta-lens device and the image sensor.

8. A multi-dimensional information processing method based on binocular polarization-sensitive meta-lens, characterized in that: The method comprises: Acquire a target image, wherein the target image is a target image of the object to be measured acquired by the four-dimensional imaging device based on the binocular polarization-sensitive metalens according to any one of claims 1 to 7; the target image includes four sub-images; Determine the depth information of the object by calculating the disparity values ​​between the four sub-images; The polarization information of the object to be measured is determined by calculating the light intensity difference between the four sub-images.

9. An electronic device, characterized in that: include: processor; a memory for storing processor-executable instructions; Wherein, the processor is configured to implement the method of claim 8 when executing the instructions stored in the memory.

10. A non-volatile computer-readable storage medium having computer program instructions stored thereon, characterized in that: When the computer program instructions are executed by a processor, the method of claim 8 is implemented.

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