Snapshot type imaging spectrometer

Abstract

The invention discloses a snapshot type imaging spectrometer, relates to the technical field of optical imaging, realizes pixel-level accurate light field control through super atoms, and has higher light field regulation and control flexibility. The quasi-continuous bound state metasurface is utilized to realize the filtering function and the imaging function at the same time, and the problem that all existing spectral imaging systems cannot utilize one element to realize the filtering function and the imaging function at the same time is solved. A plurality of images containing different spectral information can be obtained through single snapshot, and real snapshot type spectral imaging is achieved. A single-layer element is used, so that the function which can be realized by a traditional double-layer element can be realized, and the volume of the spectral imaging system is greatly reduced; in addition, high-spatial-resolution recovery can be carried out on the obtained spectral image by combining an algorithm, and an image with high spatial resolution is obtained.

Description

Technical Field

[0001] This invention relates to the field of optical imaging technology, and in particular to a snapshot imaging spectrometer. Background Technology

[0002] Optical imaging technology can acquire the spatial intensity distribution of a target, while spectral imaging technology can obtain both spatial intensity distribution and one-dimensional spectral information of a target through a single exposure, thus offering significant advantages in target detection and identification. The data composed of spatial intensity and spectral information is called a data cube. There are two main methods for acquiring data cubes: one is to perform one-dimensional or two-dimensional optomechanical scanning in the spatial dimension, such as prism dispersive imaging spectrometers and grating diffraction imaging spectrometers; the other is to scan in the spectral dimension, such as filter-type imaging spectrometers. However, neither of these methods can achieve real-time target detection. Snapshot spectral imaging technology can obtain the spatial distribution and spectral information of a target through a single imaging exposure. Based on the target spatial-spectral modulation projection principle, snapshot spectral imaging can be divided into indirect measurement type and direct measurement type. Indirect measurement type modulates and encodes the three-dimensional information of the target, consisting of two-dimensional space and one-dimensional spectrum. Reconstructing the target data requires demodulating the imaging data, similar to coded aperture spectral imaging and computational tomography spectral imaging. Direct measurement spectral imaging projects two-dimensional slices of the target's three-dimensional information onto a detector, such as filter stacking spectral imaging and image plane replication spectral imaging. Direct measurement snapshot spectral imaging technology requires no reconstruction algorithm and has a clear spatial-spectral modulation relationship; however, it sacrifices spatial resolution during spatial-spectral modulation, resulting in low spatial resolution of the reconstructed three-dimensional information, and the fabrication of mosaic-type filters is costly. Indirect measurement spectral imaging does not sacrifice spatial resolution, but the complexity of its reconstruction algorithm and the computational time required hinder its widespread adoption.

[0003] The methods related to this invention in the prior art include: (1) 202311677777.7 Off-axis reflective aperture-splitting snapshot spectral imaging optical system. This invention belongs to the field of multispectral imaging technology and discloses an off-axis reflective aperture-splitting snapshot spectral imaging optical system, including a front reflector, a field stop, a collimating reflector, an aperture array, a filter array, a small lens array, and a large-area detector. The front reflector, field stop, and collimating reflector constitute a telescope system. The aperture array and filter array split the aperture and beam. The small lens array collects the energy of multiple channels and simultaneously generates multiple spectral images in the large-area detector. This invention uses an off-axis reflective telescope system to correct the system's chromatic aberration and second-order spectrum. The aperture is split in the parallel light path provided by the telescope system, solving the parallax problem. Each independent small lens in the small lens array adopts a structure of multiple lens combinations. The spectral segment design improves image quality. This invention meets the requirements of aberration correction and image calibration for large-aperture optical systems. The system structure is simple and highly feasible.

[0004] (2) 202411883978.7 An infrared snapshot spectral imaging system based on coded filters. This invention provides an infrared snapshot spectral imaging system based on coded filters, comprising a telescope, an aperture, a collimating lens, a filter array, a microlens array, and a detector array. Light emitted from the light source passes sequentially through the telescope, aperture, collimating lens, filter array, and microlens array, and is finally received by the detector. The filters in the filter array are coded filters. The coded filters randomly transmit infrared signals according to wavelength bands. By encoding the spectrum, a high signal-to-noise ratio spectral aliasing signal is obtained. Subsequently, information decoding technology is used to restore the spectral aliasing signal to obtain a fine infrared spectrum. This invention achieves high resolution, high efficiency, band selectivity, flexibility, and strong anti-interference capability.

[0005] (3) 202510784737.5 A micro spectrometer with customizable resolution based on a transversely dispersive metasurface. This invention provides a micro spectrometer with customizable resolution based on a transversely dispersive metasurface, comprising a dispersive metasurface array structure and a focal plane pixel array. The dispersive metasurface array structure includes several array-distributed dispersive metasurface subarrays for preliminary spectral decoupling and directional focusing. The dispersive metasurface subarrays include several dispersive metasurface units and their all-dielectric substrates. The dispersive metasurface units are nanopillars with four-fold symmetry, and each nanopillar is periodically arranged. The phase of the transmitted light is dynamically adjusted according to the incident light frequency ω, so that the focal position (x', y') of the transmitted light on the focal plane changes linearly with ω. The focal plane pixel array includes a multi-element planar array composed of several pixels, which is pixel-level registered with the dispersive metasurface subarray. This invention achieves pixel-level precise focusing, effectively suppresses crosstalk, improves detection accuracy, and realizes true snapshot-style spectral imaging.

[0006] Invention (1) 202311677777.7 uses a small lens array to collect the energy of multiple channels and generate multiple spectral images simultaneously in a large array detector. However, a filter array needs to be placed in front of the small lens array, which not only increases the size of the optical system, but also has a relatively high processing cost for the filter array.

[0007] Invention (2) 202411883978.7 replaces the traditional filter in the filter array with a coded filter, and randomly passes the infrared signal through the filter according to the band. The imaging system includes a filter array and a microlens array, which makes the optical path structure larger. In addition, the decoding algorithm will reduce the real-time performance of the imaging.

[0008] Invention (3) 202510784737.5 To achieve the functions of spectral decoupling and directional convergence, the dispersive metasurface unit used employs three types of four-fold symmetric nanopillars. The nanopillars have high structural complexity, which poses a challenge to the fabrication. Fabrication errors will also affect the effects of spectral decoupling and directional convergence. Summary of the Invention

[0009] In view of the above problems, the present invention provides a snapshot imaging spectrometer for overcoming or at least partially solving the above problems. Snapshot spectral imaging is achieved based on a metasurface array of quasi-continuous domain bound states. Using a simple nanopore structure, it is not only compatible with existing fabrication processes and has low fabrication difficulty, but also greatly reduces the size of the spectral imaging system.

[0010] This invention provides the following solution: A snapshot imaging spectrometer, comprising: A microscopic imaging lens, a quasi-continuous domain bound-state microlens array, and an image sensor are arranged sequentially along the optical path; The microscopic imaging lens is used to form a reduced and inverted real image of the object to be measured, which is placed at the working distance of the microscopic imaging lens, on the image plane; The quasi-continuous domain bound state microlens array includes at least two superlens subunits with different spectral responses. Each superlens subunit includes a number of periodically arranged quasi-continuous domain bound state superatoms. Each superlens subunit is used to simultaneously perform secondary imaging on the reduced inverted real image and filter out a preset narrowband spectrum to obtain at least two sub-images containing different spectral information. The image sensor is used to capture all the sub-images in a single snapshot.

[0011] Preferably, the quasi-continuous bound state superatoms include micro / nano structures capable of exciting quasi-continuous bound state resonances, the structural parameters of which are configured to give them a single and position-controllable resonance peak within the target operating wavelength range.

[0012] Preferably, the structure of the quasi-continuous domain bound state superatom includes two rectangular holes of the same size and perpendicular to each other, and its phase response and resonant wavelength can be tuned by changing the length, width, period and rotation angle of the rectangular holes.

[0013] Preferably, the length and width of the rectangular aperture are both varied from 25 nm to 425 nm in 5 nm intervals, and the period is varied from 400 nm to 500 nm in 50 nm intervals, and the height of the quasi-continuous domain bound state superatoms is fixed at 116 nm.

[0014] Preferably, the phase response of the quasi-continuous domain bound state superatom is linearly related to the rotation angle between the two mutually perpendicular rectangular holes and the reference position, and the phase is 4 times the rotation angle.

[0015] Preferably, the material of the quasi-continuous domain bound state superatoms includes amorphous silicon; the method for preparing the quasi-continuous domain bound state microlens array includes forming all the superatomic structures of the quasi-continuous domain bound state microlens array in one step on a single-layer dielectric film using micro-nano fabrication processes.

[0016] Preferably, the quasi-continuous domain bound state microlens array operates in transmission mode, reflection mode, or simultaneous transmission and reflection mode; the operating wavelength range of the quasi-continuous domain bound state microlens array includes any electromagnetic spectrum band including visible light, infrared, terahertz, or microwave; the superlens subunits are arranged in the array at equal or unequal intervals, and the arrangement shape includes rectangular array and ring array.

[0017] Preferably, the phase distribution of the superlens subunit satisfies the lens phase formula:

[0018] In the formula: Indicates phase, Indicates the design wavelength. Indicates focal length. , This indicates the position coordinates of the superatoms in the array; The phase is achieved by adjusting the geometry and / or spatial orientation angle of the superatom.

[0019] Preferably, the image sensor is further included with an information processing device connected to it. The information processing device is configured to run an image processing algorithm for high spatial resolution restoration of all the sub-images in order to obtain a high spatial resolution image.

[0020] Preferably, the image processing algorithm includes a feature-based image registration method or a deep learning-based image registration method.

[0021] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects: This invention provides a snapshot imaging spectrometer that achieves pixel-level precise light field control through metaatoms, offering greater flexibility in light field modulation. It utilizes a quasi-continuous bound metasurface to simultaneously achieve filtering and imaging functions, solving the problem that existing spectral imaging systems cannot achieve both using a single element. A single snapshot can acquire multiple images containing different spectral information, realizing true snapshot spectral imaging. Using a single-layer element achieves the functions traditionally requiring two layers, significantly reducing the size of the spectral imaging system. Furthermore, algorithms can be combined to perform high spatial resolution reconstruction of the acquired spectral images, resulting in high spatial resolution images. Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of a snapshot imaging spectrometer provided in an embodiment of the present invention; Figure 2 This is an imaging schematic diagram of a snapshot imaging spectrometer provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of a quasi-continuous domain bound state superatom provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the superlens subunit provided in an embodiment of the present invention; Figure 5 These are the transmission spectrum curves of the nine superlens subunits provided in this embodiment of the invention; Figure 6 It is a quasi-continuous domain bound state microlens array composed of 9 superlens subunits provided in the embodiments of the present invention; Figure 7 This is a phase distribution diagram of each group of structures under load provided in the embodiments of the present invention; Figure 8 This is a focusing schematic diagram of the nine superlens subunits provided in an embodiment of the present invention; Figure 9 These are nine sub-images captured by an image sensor, as provided in this embodiment of the invention. Figure 10 These are nine sub-images with high spatial resolution restored by an algorithm, provided in this embodiment of the invention.

[0024] In the figure: 1. Microscopic imaging lens; 2. Quasi-continuous domain bound state microlens array; 3. Image sensor; 4. Information processing device. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0026] See Figure 1 , Figure 2 This invention provides a snapshot imaging spectrometer, such as... Figure 1 , Figure 2 As shown, the imaging spectrometer may include: The microscopic imaging lens 1, the quasi-continuous domain bound state microlens array 2, and the image sensor 3 are arranged sequentially along the optical path; The microscopic imaging lens 1 is used to form a reduced and inverted real image of the object to be measured placed at the working distance of the microscopic imaging lens 1 on the image plane; The quasi-continuous domain bound state microlens array 2 includes at least two superlens subunits with different spectral responses. Each superlens subunit includes a number of periodically arranged quasi-continuous domain bound state superatoms. Each superlens subunit is used to simultaneously perform secondary imaging on the reduced inverted real image and filter out a preset narrowband spectrum to obtain at least two sub-images containing different spectral information. The image sensor 3 is used to acquire all the sub-images.

[0027] The snapshot imaging spectrometer provided in this invention integrates filter and lens functions by employing a superlens array based on quasi-continuous bound states (q-BIC), enabling multi-channel snapshot spectral imaging while reducing system size. Through algorithmic processing of the acquired multi-channel images, high spatial-temporal resolution target intensity and spectral information acquisition can also be achieved. Furthermore, unlike mosaic filters which require multiple coating processes, the proposed q-BIC superlens array can be fabricated with a single electron beam exposure, shortening processing time and reducing processing costs.

[0028] This invention applies quasi-continuous domain bound state metasurface arrays to spectral imaging. Snapshot-style spectral imaging is achieved using a metasurface array based on quasi-continuous domain bound states. The simple nanopore structure is compatible with existing fabrication processes, has low fabrication difficulty, and significantly reduces the size of the spectral imaging system. Spectral information with a bandwidth of less than 10 nm is acquired through a single metalens, and high-resolution images can be obtained through spectral reconstruction using a relatively simple algorithm.

[0029] The quasi-continuous bound-state microlens array provided in this invention comprises a plurality of periodically arranged quasi-continuous bound-state superatoms. Each superlens subunit includes a plurality of quasi-continuous bound-state superatoms. The resonant wavelength (i.e., the filtering center wavelength) and phase response of the quasi-continuous bound-state superatoms can be precisely controlled by changing their geometric dimensions (such as the length, width, and period of the cross-shaped aperture arm). By combining geometric phase (such as Pancharatnam-Berry phase) or propagation phase principles, the secondary phase surface distribution required by the lens is mapped onto the spatial orientation of each superatom, thereby achieving focusing imaging function while filtering.

[0030] In a specific implementation, embodiments of the present invention may provide that the quasi-continuous bound state superatom includes a micro / nano structure capable of exciting quasi-continuous bound state resonance, the structural parameters of which are configured to have a single and position-controllable resonance peak within the target operating band.

[0031] The structure of the quasi-continuous domain bound state superatom includes two rectangular holes of the same size and perpendicular to each other. The phase response and resonant wavelength can be tuned by changing the length, width, period and rotation angle of the rectangular holes.

[0032] The length and width of the rectangular aperture both vary from 25 nanometers to 425 nanometers in 5-nanometer intervals, and the period varies from 400 nanometers to 500 nanometers in 50-nanometer intervals. The height of the quasi-continuous domain bound state superatoms is fixed at 116 nanometers.

[0033] The phase response of the quasi-continuous domain bound state superatom is linearly related to the rotation angle between two mutually perpendicular rectangular holes and the reference position, and the phase is 4 times the rotation angle.

[0034] In the specific preparation of the quasi-continuous domain bound state superatoms, the material of the quasi-continuous domain bound state superatoms can include amorphous silicon; the method for preparing the quasi-continuous domain bound state microlens array includes forming all the superatomic structures of the quasi-continuous domain bound state microlens array on a single layer dielectric film in one step through micro-nano fabrication processes.

[0035] Furthermore, the quasi-continuous domain bound state microlens array 2 operates in transmission mode, reflection mode, or simultaneous transmission and reflection mode; the operating wavelength range of the quasi-continuous domain bound state microlens array 2 includes any electromagnetic spectrum band including visible light, infrared, terahertz, or microwave; the superlens subunits are arranged in the array at equal or unequal intervals, and the arrangement shape includes rectangular array and ring array.

[0036] The phase distribution of the superlens subunit satisfies the lens phase formula:

[0037] In the formula: Indicates phase, Indicates the design wavelength. Indicates focal length. , This indicates the position coordinates of the superatoms in the array; The phase is achieved by adjusting the geometry and / or spatial orientation angle of the superatom.

[0038] To achieve sharpening of all sub-images, embodiments of the present invention may also provide an information processing device 4 connected to the image sensor. The information processing device 4 is configured to run an image processing algorithm for high spatial resolution restoration of all sub-images, thereby obtaining a high spatial resolution image. The image processing algorithm includes feature-based image registration methods or deep learning-based image registration methods.

[0039] As can be seen, the core of the snapshot imaging spectrometer provided in this embodiment of the invention lies in the use of a superlens array based on a quasi-continuous bound state. The system mainly includes a microscopic imaging lens 1, a quasi-continuous bound state microlens array 2, and an image sensor 3. The target object is imaged once onto the object plane of the microlens array (i.e., near the image plane of the imaging lens) by the microscopic imaging lens. It is understood that in some application scenarios where high imaging quality is not required, the microscopic imaging lens may not be necessary; the object can be placed directly within the working distance range of the quasi-continuous bound state microlens array, and the object can be imaged directly through the array.

[0040] The quasi-continuous domain bound-state microlens array 2 consists of multiple superlens sub-units, each composed of periodically arranged quasi-continuous domain bound-state superatoms (such as cross-shaped nanopores) with specific geometric parameters. Each sub-unit is designed to have high transmittance only for a specific narrowband wavelength (e.g., bandwidth <10nm), and simultaneously applies a specific focusing phase distribution to this narrowband light, thereby achieving narrowband filtering and secondary imaging of the primary image. Finally, the sub-images of multiple different spectral channels formed by all sub-units are simultaneously captured by the rear-mounted image sensor 3 in a single exposure. Furthermore, these sub-images can be reconstructed using image processing algorithms to reconstruct a high spatial resolution data cube.

[0041] The snapshot imaging spectrometer provided in this invention will be described in detail below, taking a continuous bound-state superlens array made of amorphous silicon material as an example.

[0042] The snapshot imaging spectrometer provided in this invention mainly consists of a microscopic imaging lens 1, a quasi-continuous domain bound-state microlens array 2, an image sensor 3, and an information processing device 4. The imaging results acquired by the image sensor are processed by the information processing device to obtain a high spatial resolution image. Specifically, the object to be measured is placed at the working distance of the microscopic imaging lens. After passing through the microscopic imaging lens, a reduced and inverted real image is formed on the image plane. This image plane corresponds to the object plane of the quasi-continuous domain bound-state microlens array. After each sub-lens in the quasi-continuous domain bound-state microlens array images the object, the image sensor placed at the image plane of the quasi-continuous domain bound-state microlens array captures all sub-images, and the spatial resolution is improved by an algorithm running on the information processing device.

[0043] In one implementation, the quasi-continuous domain bound-state microlens array provided by this invention can operate in the 1 μm-1.7 μm band, imaging nine specific wavelengths within this band. Its design and usage process are as follows: Taking a quasi-continuous bound-state superatomic structure with quasi-continuous bound-state characteristics as an example, this type of quasi-continuous bound-state superatom consists of two rectangular apertures of the same size and perpendicular to each other. Using micro-nano optics methods and the finite-difference time-domain method, under normal incident circularly polarized light in the 1 μm-1.7 μm wavelength band, the complex amplitude response of transmitted light corresponding to different sizes of the quasi-continuous bound-state superatoms with different geometric dimensions was obtained, thus constructing a database of the complex amplitude response of the superatoms. During the scan, the length L and width W of the rectangles varied from 25 nm to 425 nm at 5 nm intervals, the period P varied from 400 nm to 500 nm at 50 nm intervals, and the height H of the superatoms was fixed at 116 nm. The phase response of the superatoms is linearly related to the rotation angle between the two perpendicular rectangular apertures and the reference position, and the phase is 4 times the rotation angle, φ=4×θ.

[0044] By altering the geometric dimensions of superatoms and selecting superatomic structures with specific resonant peaks, the geometric dimension information (L, W, H) of nine superatomic structures was determined. These nine structures have different dimensions, and their corresponding resonant peak positions also differ, with only one resonant peak within the wavelength range of 1 μm–1.7 μm. For example... Figure 3 , Figure 4 , Figure 5 .

[0045] The phase distribution of the superlens is calculated using the lens phase formula, which is as follows:

[0046] In the formula: Indicates phase, Indicates the design wavelength. Indicates focal length. , This represents the position coordinates of the superatom in the array.

[0047] Using this phase distribution, nine superlenses were constructed in a 3×3 arrangement. The superatomic size of each of these nine superlenses corresponds to one of the nine selected superatomic structures. In designing each superlens, a PB phase was introduced, and the rotation angle of the superatoms was θ = φ / 4, thereby achieving selective focusing / imaging effects, such as... Figure 6 , Figure 7 , Figure 8 As shown.

[0048] The continuous bound-state microlens array was placed near the image plane of the microscopic imaging lens, and its positional relationship was adjusted to enable it to perform secondary imaging of the image formed by the microscopic imaging lens. Imaging was performed at the image plane of the quasi-continuous bound-state microlens array, and nine sub-images were acquired using an image sensor, such as... Figure 9 As shown.

[0049] The imaging system will capture multiple low-spatial-resolution images containing different spectral information of the target. Using a simple algorithm, image processing will be performed on these nine sub-images to obtain a high-spatial-resolution image, such as... Figure 10 As shown.

[0050] The algorithm provided by this invention can include various methods, such as feature-based image registration schemes or deep learning-based image registration schemes. Through feature matching, high spatial resolution image restoration is ultimately achieved.

[0051] In practice, a feature matching method based on scale-invariant feature transformation can be used to register the nine sub-images with sub-pixel accuracy, correcting for minute displacements and deformations caused by the optical system or detector.

[0052] Then, an image super-resolution reconstruction algorithm based on convex optimization is adopted to reconstruct a high spatial resolution image for each spectral channel by utilizing the complementary information between multi-channel images.

[0053] Finally, the high-resolution images from the nine channels are combined to obtain a high spatial-hyperspectral resolution data cube of the target.

[0054] This embodiment uses nine superlens arrays with different operating wavelengths to acquire different spectral information of the target image through a single snapshot. However, by changing the structural size of the superatoms, a larger number of superlens arrays can be designed to achieve broadband spectral imaging. In the embodiments of this invention, quasi-continuous bound states are excited through two mutually perpendicular rectangular apertures, but the scope of protection of this invention is not limited to a specific structure. Alternatively, any equivalent structure capable of exciting quasi-continuous bound states should be covered within the scope of this invention. Similarly, the image reconstruction algorithm mentioned in this invention is merely an example, and any other algorithm or model capable of achieving similar functionality should be covered within the scope of this invention.

[0055] As can be seen, the quasi-continuous domain bound-state microlens array provided in this embodiment integrates lens function and narrowband filtering function, realizing the functions of two devices with a single device. In contrast, all existing spectral imaging systems cannot simultaneously achieve filtering and imaging functions using a single element. This imaging spectrometer achieves both filtering and imaging functions through the refined design of the metasurface.

[0056] Meanwhile, the quasi-continuous bound-state microlens array is not limited to transmission mode; it can also operate in reflection mode or simultaneous transmission and reflection mode. The operating wavelength is not limited to the wavelengths mentioned in the embodiments but can be extended to any electromagnetic wave range. It includes any geometry conceptually a quasi-continuous bound-state metasurface. The material is not limited to the amorphous silicon described in the embodiments. Its arrangement can be equally spaced or unequally spaced, and can be ring-shaped, square-shaped, etc.

[0057] Through simulation and experimental verification, the experiment shows that the quasi-continuous bound state superlens array can achieve focusing and imaging effects at the designed wavelength, and the working wavelengths of the superlens array are free from crosstalk. While achieving high-quality focusing effect, the experimentally measured imaging resolution is close to the diffraction limit (181 lp / mm). Through the algorithm, high spatial resolution image restoration is achieved.

[0058] In summary, the snapshot imaging spectrometer provided by this invention achieves pixel-level precise light field control through metaatoms, providing greater flexibility in light field modulation. It utilizes a quasi-continuous bound metasurface to simultaneously achieve filtering and imaging functions, solving the problem that existing spectral imaging systems cannot achieve both using a single element. A single snapshot can acquire multiple images containing different spectral information, realizing true snapshot spectral imaging. Using a single-layer element, it achieves the functions that traditionally require two-layer elements, significantly reducing the size of the spectral imaging system. Furthermore, it can be combined with algorithms to perform high spatial resolution reconstruction of the acquired spectral images, resulting in high spatial resolution images.

[0059] The present invention can also provide an imaging method for the above-described snapshot imaging spectrometer, comprising: The object under test forms a first image on the image plane of the microscope imaging lens; The quasi-continuous domain bound state microlens array receives the first image so that all the superlens sub-units of the quasi-continuous domain bound state microlens array respectively perform narrowband filtering and secondary imaging on the first image, and obtain at least two sub-images containing different spectral information at the image plane of the quasi-continuous domain bound state microlens array. The image sensor captures all sub-images in a single exposure. An algorithm for high spatial resolution restoration is used to process all the acquired sub-images to obtain a high spatial resolution target image.

[0060] It should be noted that in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0061] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that the present invention can be implemented by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in various embodiments or some parts of the embodiments of the present invention.

[0062] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for system or system embodiments, since they are basically similar to method embodiments, the description is relatively simple, and relevant parts can be referred to the descriptions in the method embodiments. The systems and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0063] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A snapshot imaging spectrometer, characterized in that, It includes a microscopic imaging lens, a quasi-continuous domain bound-state microlens array, and an image sensor arranged sequentially along the optical path; The microscopic imaging lens is used to form a reduced and inverted real image of the object to be measured, which is placed at the working distance of the microscopic imaging lens, on the image plane; The quasi-continuous domain bound state microlens array includes at least two superlens subunits with different spectral responses. Each superlens subunit includes a number of periodically arranged quasi-continuous domain bound state superatoms. Each superlens subunit is used to simultaneously perform secondary imaging on the reduced inverted real image and filter out a preset narrowband spectrum to obtain at least two sub-images containing different spectral information. The image sensor is used to capture all the sub-images in a single snapshot.

2. The snapshot imaging spectrometer according to claim 1, characterized in that, The quasi-continuous bound state superatoms include micro / nano structures capable of exciting quasi-continuous bound state resonances, the structural parameters of which are configured to give them a single, position-controllable resonance peak within the target operating wavelength range.

3. The snapshot imaging spectrometer according to claim 2, characterized in that, The structure of the quasi-continuous domain bound state superatom includes two rectangular holes of the same size and perpendicular to each other. The phase response and resonant wavelength can be tuned by changing the length, width, period and rotation angle of the rectangular holes.

4. The snapshot imaging spectrometer according to claim 3, characterized in that, The length and width of the rectangular aperture both vary from 25 nm to 425 nm in 5 nm increments, and the period varies from 400 nm to 500 nm in 50 nm increments. The height of the quasi-continuous domain bound state superatoms is fixed at 116 nm.

5. The snapshot imaging spectrometer according to claim 3, characterized in that, The phase response of the quasi-continuous domain bound state superatom is linearly related to the rotation angle between two mutually perpendicular rectangular holes and the reference position, and the phase is 4 times the rotation angle.

6. The snapshot imaging spectrometer according to claim 1, characterized in that, The material of the quasi-continuous domain bound state superatoms includes amorphous silicon; the method for preparing the quasi-continuous domain bound state microlens array includes forming all the superatomic structures of the quasi-continuous domain bound state microlens array in one step on a single-layer dielectric film using micro-nano fabrication processes.

7. The snapshot imaging spectrometer according to claim 1, characterized in that, The quasi-continuous domain bound state microlens array operates in transmission mode, reflection mode, or simultaneous transmission and reflection mode; the operating wavelength range of the quasi-continuous domain bound state microlens array includes any electromagnetic spectrum band including visible light, infrared, terahertz, or microwave; the superlens subunits are arranged in the array at equal or unequal intervals, and the arrangement shape includes rectangular array and ring array.

8. The snapshot imaging spectrometer according to claim 1, characterized in that, The phase distribution of the superlens subunit satisfies the lens phase formula: In the formula: Indicates phase, Indicates the design wavelength. Indicates focal length. , This indicates the position coordinates of the superatoms in the array; The phase is achieved by adjusting the geometry of the superatom and / or its spatial orientation angle.

9. The snapshot imaging spectrometer according to claim 1, characterized in that, It also includes an information processing device connected to the image sensor, the information processing device being configured to run an image processing algorithm for high spatial resolution restoration of all the sub-images in order to obtain a high spatial resolution image.

10. The snapshot imaging spectrometer according to claim 9, characterized in that, The image processing algorithm includes feature-based image registration methods or deep learning-based image registration methods.

Images