Optical reconstruction method, device and system based on multiple holograms

Abstract

The application relates to the technical field of optical reconstruction, and discloses a multi-hologram-based optical reconstruction method, device and system, the method comprising the following steps: acquiring a target gray image set, converting each gray image in the gray image set into a holographic image to obtain a holographic image set; performing additional phase embedding on the light field of each holographic image in the holographic image set to obtain a composite holographic image; extracting a polarized light field distribution according to the light field phase distribution of the composite holographic image; and performing optical reconstruction on the composite holographic image according to the polarized light field distribution to obtain an actual light field distribution. Through the implementation of the application, the accurate extraction of a polarization state and the dynamic real-time regulation of the polarization state of a holographic light field can be realized, so that the accuracy of optical reconstruction in holographic imaging is improved.

Description

Technical Field

[0001] This invention relates to the field of optical reconstruction technology, and in particular to an optical reconstruction method, apparatus and system based on multiple holograms. Background Technology

[0002] Holographic imaging, a technology that reconstructs a true three-dimensional image of an object by recording and reconstructing the amplitude and phase information of light waves, has demonstrated significant application value in multiple fields such as display, storage, and measurement. For example, in the medical field, holographic imaging can be used for surgical navigation, medical image storage and display, providing doctors with more intuitive and accurate information to assist in surgical procedures and disease diagnosis; in the industrial manufacturing field, holographic imaging technology can be used in product design, quality inspection, and other processes to improve production efficiency and product quality.

[0003] Existing holographic imaging technology still has the following shortcomings:

[0004] First, because the phase delay characteristics of the geometric phase metasurface are inversely related to the incident light wavelength, such devices can only work stably within a specific wavelength range. When deviating from the specific wavelength range, the polarization conversion efficiency decreases, making them incompatible with wide-spectrum scenarios and resulting in poor adaptability in holographic imaging.

[0005] Second, when multiple polarization holograms are loaded using spatial multiplexing technology, the diffraction light fields of different channels are prone to overlap in adjacent areas during propagation, which directly reduces the purity of the polarization signal, affects the resolution and fidelity of the holographic image, and results in poor accuracy of holographic imaging.

[0006] Third, the polarization state switching of existing metasurface-based vector holography technology relies on mechanical reconstruction, and the response time is usually maintained at the millisecond level, which cannot meet the speed-sensitive dynamic control requirements such as real-time interaction and dynamic scene simulation.

[0007] Therefore, how to achieve dynamic real-time control of the polarization state of the holographic light field to improve the accuracy of holographic imaging has become an urgent problem to be solved. Summary of the Invention

[0008] This invention provides an optical reconstruction method, apparatus, and system based on multiple holograms, the main purpose of which is to solve the problem of low accuracy in holographic imaging.

[0009] To achieve the above objectives, the present invention provides an optical reconstruction method based on multiple holograms, comprising: acquiring a target grayscale image set; converting each grayscale image in the grayscale image set into a holographic image to obtain a holographic image set; performing additional phase embedding on the light field of each holographic image in the holographic image set to obtain a composite hologram; extracting the polarization light field distribution corresponding to the composite hologram based on the phase distribution of the light field of the composite hologram; and performing optical reconstruction on the composite hologram based on the polarization light field distribution to obtain the actual light field distribution.

[0010] The present invention also provides an optical reconstruction device based on multiple holograms, the device comprising: a laser for generating excitation light; a phase diffraction device for receiving the excitation light and performing additional phase embedding on the light fields of multiple holographic images according to the excitation light to obtain a composite hologram; a polarization converter for extracting the polarization light field distribution of the composite hologram; and an objective lens for performing Fourier transform on the polarization light field distribution to obtain the actual light field distribution.

[0011] This invention also provides an optical reconstruction system based on multiple holograms. The system includes: a grayscale image conversion module for acquiring a target grayscale image set and converting each grayscale image in the grayscale image set into a holographic image to obtain a holographic image set; an additional phase embedding module for performing additional phase embedding on the light field of each holographic image in the holographic image set to obtain a composite hologram; a polarization light field distribution extraction module for extracting the polarization light field distribution corresponding to the composite hologram based on the light field phase distribution of the composite hologram; and an optical reconstruction module for performing optical reconstruction on the composite hologram based on the polarization light field distribution to obtain the actual light field distribution.

[0012] This invention converts each grayscale image in a grayscale image set into a holographic image to obtain a holographic image set, which can encode all the information of the object light wave, providing a foundation for subsequent reconstruction of the real light field distribution. Additional phase embedding is performed on the light field of each holographic image to embed additional phase information corresponding to the target polarization state, displaying holograms of different polarization states to obtain a composite hologram. The polarization light field distribution corresponding to the composite hologram is extracted based on the complex amplitude distribution of the light field, enabling accurate extraction of the polarization state of the composite hologram. Optical reconstruction of the composite hologram based on the polarization light field distribution yields the actual light field distribution, enabling dynamic real-time control of the holographic light field polarization state to improve the accuracy of optical reconstruction in holographic imaging. Attached Figure Description

[0013] Figure 1 This is a schematic flowchart of an optical reconstruction device based on multiple holograms provided in an embodiment of the present invention;

[0014] Figure 2 This is a schematic diagram of the optical reconstruction of a hologram according to an embodiment of the present invention;

[0015] Figure 3 This is a schematic flowchart of an optical reconstruction method based on multiple holograms provided in an embodiment of the present invention;

[0016] Figure 4 This is a functional block diagram of an optical reconstruction system based on multiple holograms provided in an embodiment of the present invention.

[0017] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0018] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0019] Reference Figure 1 As shown, the optical reconstruction device based on multiple holograms includes a laser 1, a polarizer 2, a first cemented doublet lens 3, a second cemented doublet lens 4, a phase diffraction device 5, a first reflecting mirror 6, a second reflecting mirror 7, a third cemented doublet lens 8, a fourth cemented doublet lens 9, a polarization converter 10, an objective lens 11, a charge-coupled device camera 12, and an industrial controller 13.

[0020] Among them, polarizer 2 is used to convert the excitation light generated by laser 1 into horizontally polarized light;

[0021] The first cemented doublet 3 and the second cemented doublet 4 form a 4f (4-f system) optical system, which is a Fourier transform optical path unit of "two lenses + two focal planes" with a total length ≈ 4 × focal length. Here, f is the focal length of the lens, the distance from the polarizer 2 to the first cemented doublet 3 is f, the distance between the first cemented doublet 3 and the second cemented doublet 4 is 2f, and the distance from the second cemented doublet 4 to the phase diffraction device 5 is f. Therefore, the optical imaging system composed of the two first cemented doublet lenses 3 and 4 with the same focal length constitutes a 4f optical system. Through the first cemented doublet lens 3 and the second cemented doublet lens 4, horizontally polarized light can be shaped and expanded, and transmitted to the phase diffraction device 5, ensuring that the input linearly polarized light is transmitted to the phase diffraction device 5 without distortion, thus improving the accuracy of excitation light transmission.

[0022] For example, the excitation light generated by laser 1 can be Gaussian linearly polarized light, such as Gaussian excitation light with a diameter of 2 mm and a wavelength of 532 nm. A polarizer 2 is set for the wavelength of the incident Gaussian excitation light. Preferably, the polarizer 2 can be a broadband polarization band that includes the wavelength of the Gaussian excitation light in the working band, and its polarization direction is horizontal, so that the Gaussian excitation light can be converted into horizontally linearly polarized light.

[0023] Furthermore, the 4f optical system performs two Fourier transforms on the input horizontally polarized light, thereby physically expanding the "spatial frequency" on the intermediate focal plane (Fourier plane). The second cemented doublet 4 then transforms the modulated spectrum back into the spatial domain to obtain the processed image, which is convenient for subsequent processing.

[0024] Furthermore, the phase diffraction device 5 is implemented by encoding with a phase-type spatial light modulator or by directly processing a coating to achieve additional phase embedding of the holographic image;

[0025] The polarization state of the phase diffraction device 5 is related to the setting of the phase parameter, which can be dynamically adjusted according to requirements. For example, for the linear polarization state, the phase parameter is... When the preset first polarization phase factor The preset second polarization phase factor When the polarization value is zero, the polarization state is a horizontal linear polarization state; where, Represents integers, This indicates a phase take operation. Represents the imaginary number symbol, Indicates the azimuth angle of objective lens 11;

[0026] In the preset first polarization phase factor The preset second polarization phase factor When the polarization ratio is π / 2, the polarization state is vertical linear polarization; while for circular polarization, the phase parameter is... In the preset first polarization phase factor The preset second polarization phase factor When the polarization factor is zero, the polarization state is a left-handed circular polarization state; at the preset first polarization phase factor The preset second polarization phase factor When =0, the polarization state is a right-hand circular polarization state.

[0027] Therefore, the phase information of light fields with different polarization states can be embedded into the phase of the light fields of multiple holographic images using the phase diffraction device 5, resulting in a holographic light field with polarization-related phase information for each holographic image. For example, the holographic image is the holographic image corresponding to the object that needs to be optically reconstructed, and can be obtained by converting a grayscale image.

[0028] Furthermore, multiple holographic images with additional phases are assigned target positions on the final two-dimensional reconstruction plane according to the complex amplitude distribution of the light field. This places each phase-embedded hologram into the corresponding pixel region of the composite hologram (e.g., the complex amplitude distribution of the light field is: the first holographic image is placed in the upper left corner of the two-dimensional reconstruction plane, and the second holographic image is placed in the upper right corner of the two-dimensional reconstruction plane). Unassigned areas are filled with zero amplitude or zero phase to avoid overlap, thus obtaining the composite hologram.

[0029] Preferably, the first reflector 6 and the second reflector 7 are arranged opposite each other, and are used to incident the light field of the composite hologram onto the polarization converter 10 from different paths and angles. At the same time, the reflectors can "fold" the light path, making the structure of the entire optical reconstruction device based on multiple holograms more compact, adapting to the limited optical platform area, and improving the applicability of optical reconstruction.

[0030] Furthermore, a third cemented doublet lens 8 and a fourth cemented doublet lens 9 are disposed between the second reflector 7 and the polarization converter 10 to form a second 4f optical system;

[0031] The distance between the third cemented doublet 8 and the fourth cemented doublet 9 is twice the focal length, the distance from the second reflecting mirror 7 to the third cemented doublet 8 is one focal length, and the distance from the fourth cemented doublet 9 to the polarization converter 10 is one focal length. The third cemented doublet 8 and the fourth cemented doublet 9 can transmit the light field of the composite hologram completely and faithfully to the position (output surface) of the polarization converter 10, thereby improving the accuracy of optical reconstruction.

[0032] Preferably, the phase diffraction device 5 is disposed on the front focal plane of the third cemented doublet lens 8.

[0033] Furthermore, by forming a second 4f optical system through the third cemented doublet lens 8 and the fourth cemented doublet lens 9, the phase diffraction device 5 and the polarization converter 10 are conjugate, so that the incident surface of the polarization converter 10 is precisely located on the conjugate image plane of the output surface of the phase diffraction device 5, thereby achieving precise relay and alignment of the light field and improving the stability of the actual light field distribution generation.

[0034] In this embodiment of the invention, the charge-coupled device camera 12 is disposed at the rear focal plane of the objective lens 11, and is used to generate an actual light field hologram corresponding to the actual light field distribution based on the light field intensity information of the actual light field distribution.

[0035] The polarization converter 10 is used to extract the polarization field distribution corresponding to the composite hologram. It can decompose the light field of the incident composite hologram into the corresponding polarization state, thereby realizing the extraction of the polarization field distribution of the composite hologram.

[0036] In detail, the objective lens 11 is used to perform a Fourier transform on the polarization field distribution of the composite hologram to obtain the actual light field. For example, the objective lens has a numerical aperture of 0.01 and a wavelength of 532 nm for linearly polarized light, m=128. After being modulated by different phase patterns, the actual light field carrying different polarization states can be emitted from the objective lens 11 and recorded by the charge-coupled device camera 12.

[0037] Among them, the charge-coupled device camera 12 is a camera that uses a charge-coupled device (CCD) as an image sensor. It can collect interference fringes of the actual light field distribution carrying polarization information, reconstruct the interference fringes numerically, and generate an actual light field hologram including amplitude and phase.

[0038] For example, such as Figure 2 As shown, phase embedding is performed on each hologram by phase diffraction device 5, so that the phase information of the light field with different polarization states is embedded into the phase of the light field of multiple holograms, and a holographic light field with polarization-related phase information is obtained for each hologram.

[0039] For example, Figure 2 In the diagram, (a), (c), (e), and (g) represent multiple holographic images after embedding phase information of light fields with different polarization states; (b), (d), (f), and (h) represent phase information of light fields with different polarization states embedded in the phase diffraction device 5; (i) represents a composite hologram generated from holographic images (a), (c), (e), and (g) based on the complex amplitude distribution of the light field; and (i) represents a hologram that simultaneously possesses phase information of light fields with different polarization states (b), (d), (f), and (h).

[0040] Furthermore, such as Figure 2 As shown, the actual light field hologram corresponding to the actual light field distribution is recorded by the charge-coupled device camera 12. After the light field of the composite hologram shown in (i) passes through the horizontal polarizer, the cat pattern disappears, as shown in (k). This proves that the phase information related to polarization embedded in the holographic image (c) corresponding to the cat pattern is a vertically linearly polarized state.

[0041] exist Figure 2 The light field of the composite hologram shown in (i) first passes through a quarter-wave plate at a 45-degree angle to the horizontal, and then through a vertical linear polarizer. The actual light field hologram recorded by the charge-coupled device camera 12 shows the bird pattern disappearing, as... Figure 2 As shown in (l), it is proved that the polarization-related phase information embedded in the holographic image (e) corresponding to the bird pattern is a left-handed circularly polarized state;

[0042] when Figure 2 The light field of the composite hologram shown in (i) first passes through a quarter-wave plate at a 45-degree angle to the horizontal, and then through a horizontal linear polarizer. The actual light field hologram recorded by the charge-coupled device camera 12 is the disappearance of the rabbit pattern, as shown in the image. Figure 2 As shown in (m), it is proved that the phase information related to polarization embedded in the holographic image (g) corresponding to the rabbit pattern is a right-handed circularly polarized state;

[0043] when Figure 2After passing through a vertical polarizer, the actual light field hologram recorded by the charge-coupled device camera 12 shows the disappearance of the puppy pattern, as shown in the image. Figure 2 As shown in (n), it is proved that the phase information related to polarization embedded in the holographic image (a) corresponding to the puppy pattern is a horizontal linear polarization state.

[0044] Therefore, by using an optical reconstruction device based on multiple holograms, the polarization state of the light field of the holographic image can be dynamically and in real time controlled by the phase diffraction device 5, thereby improving the accuracy of optical reconstruction.

[0045] Preferably, the optical reconstruction device based on multiple holograms may further include an industrial controller 13, which is electrically connected to the charge-coupled device camera 12, for controlling the charge-coupled device camera 12 to generate an actual light field hologram corresponding to the actual light field distribution.

[0046] Specifically, the industrial controller 13 is a dedicated computer or electronic system used for automated production, process control, or electromechanical equipment management.

[0047] This application provides an optical reconstruction method based on multiple holograms. The executing entity of the optical reconstruction method based on multiple holograms includes, but is not limited to, at least one of the following electronic devices that can be configured to execute the method provided in this application: a server, a terminal, etc. In other words, the optical reconstruction method based on multiple holograms can be executed by software or hardware installed on a terminal device or a server device; the software can be a blockchain platform. The server includes, but is not limited to, a single server, a server cluster, a cloud server, or a cluster of cloud servers. The server can be an independent server or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, content delivery networks (CDNs), and big data and artificial intelligence platforms.

[0048] Reference Figure 3 The diagram shown is a flowchart illustrating an optical reconstruction method based on multiple holograms according to an embodiment of the present invention. In this embodiment, the optical reconstruction method based on multiple holograms includes:

[0049] S1. Obtain the target grayscale image set, and convert each grayscale image in the grayscale image set into a holographic image to obtain a holographic image set.

[0050] In this embodiment of the invention, the target grayscale image set is a collection of grayscale images of the object to be optically reconstructed. The grayscale values ​​(0~255) in the grayscale images correspond to the amplitude of the light field (the brighter the grayscale, the larger the amplitude), and can then be converted into holographic images based on the target grayscale images.

[0051] Specifically, each grayscale image in the grayscale image set is converted into a holographic image to obtain a holographic image set, including: unifying the image size of each grayscale image to obtain a unified grayscale image, mapping the grayscale values ​​of the unified grayscale image to an amplitude distribution; replacing the amplitude of a preset initial reconstruction plane according to the amplitude distribution to obtain an initial hologram; and iteratively optimizing the phase of the initial hologram to obtain a holographic image set.

[0052] In this embodiment of the invention, image size unification can be achieved by adjusting the image resolution of each grayscale image to an integer power of 2, such as 256×256 or 512×512 grayscale images. The grayscale values ​​of the unified grayscale images are then normalized, thereby mapping the grayscale value (0~255) of each pixel to the object light amplitude (0~1), thus obtaining the amplitude distribution corresponding to the unified grayscale image.

[0053] Furthermore, the preset initial reconstruction plane is a preset hologram plane. The amplitude of the reconstruction plane can be set to the uniform incident light amplitude (such as a constant 1), and the phase is initialized to a random phase (or zero phase). The initial reconstruction plane and the frequency domain plane (Fourier surface / spectral surface) are iteratively optimized to finally obtain a hologram that simultaneously contains the object light amplitude (grayscale information) and phase.

[0054] In this embodiment of the invention, the Gerchberg-Saxton (GS) algorithm can be used to iteratively optimize the initial hologram. Specifically, the initial hologram is a complex amplitude distribution (complex form) consisting of amplitude multiplied by phase. A Fourier transform is performed on the initial hologram to obtain the complex amplitude distribution of the reconstruction plane. The phase of the current complex amplitude of the initial hologram is retained, and the amplitude is replaced with the amplitude corresponding to the amplitude distribution of the uniform grayscale image. An inverse Fourier transform is performed on the updated complex amplitude to return to the hologram plane. The phase of the current complex amplitude is retained again, and the amplitude is replaced with the amplitude of the uniform incident light. The process is repeated, returning to the steps of performing a Fourier transform on the initial hologram to obtain the complex amplitude distribution of the reconstruction plane. This iterative optimization of the initial hologram continues until the phase difference between two iterations is less than a threshold, resulting in a holographic image set corresponding to each grayscale image in the grayscale image set.

[0055] In this embodiment of the invention, all information of the object light wave is encoded through holographic images, providing a foundation for subsequent reconstruction of the real light field distribution.

[0056] S2. Add phase embedding to the light field of each holographic image in the holographic image set to obtain a composite hologram.

[0057] In this embodiment of the invention, additional phase embedding involves embedding additional phase information corresponding to the target polarization state into the phase of the holographic image. The target polarization state is the polarization characteristic state of the excitation light (i.e., the illumination light used to illuminate the hologram to reconstruct the object light wave) that is pre-designed for optical reconstruction. It is the vibration direction distribution of the light field in a plane perpendicular to the propagation direction, which determines the polarization matching degree of optical reconstruction and the final optical effect.

[0058] Specifically, the optical field of each holographic image in the holographic image set is additionally phase-embedded to obtain a composite hologram, including: acquiring the horizontally polarized light corresponding to the preset excitation light; performing phase modulation on the horizontally polarized light to obtain polarization phase information; using a preset phase embedding formula to additionally phase-embed the optical field of each holographic image according to the polarization phase information to obtain the complex amplitude distribution of the optical field; and generating a composite hologram corresponding to the holographic image set according to the complex amplitude distribution of the optical field.

[0059] In this embodiment of the invention, the excitation light refers to the coherent light beam used to illuminate the holographic image set, so that each hologram diffracts a complex amplitude wavefront that is exactly the same as the original object light wave, thereby optically reconstructing the light field of the hologram in space.

[0060] Specifically, a polarizer can be used to convert the excitation light into horizontally linearly polarized light, and then a preset phase diffraction device can be used to modulate the phase of the horizontally linearly polarized light to generate a holographic light field carrying phase information related to the target polarization state.

[0061] In this embodiment of the invention, the phase embedding formula is expressed as:

[0062]

[0063] in, Indicates the complex amplitude distribution of the light field. This indicates a phase take operation. The total number of holographic images, Indicates the first The amplitude of a holographic image, Represents the imaginary number symbol, Indicates the first Phase distribution of a holographic image, This represents the phase distribution in polarization phase information.

[0064] Specifically, the polarization phase information includes the phase distribution corresponding to different polarization states, such as the phase distribution corresponding to left-handed and right-handed circular polarization states, linear polarization states, and vector polarization states, as well as the phase distribution corresponding to horizontal polarization states. It includes at least two of linear polarization, circular polarization, and vector polarization.

[0065] In this process, horizontally polarized light can be controlled to enter a pre-constructed phase diffraction device, and a holographic light field containing phase information related to different polarization states modulated by the phase diffraction device can be collected to obtain polarization phase information.

[0066] In this embodiment of the invention, the complex amplitude distribution of the light field of each holographic image can be obtained through the complex amplitude distribution of the light field of each holographic image, thereby meeting the dynamic real-time control requirements of the polarization state of the light field of the holographic image and improving the accuracy of optical reconstruction.

[0067] In this embodiment of the invention, the composite hologram is formed by arranging multiple holographic images in a preset space to create a single composite hologram, ensuring that the corresponding light fields are staggered in the two-dimensional coordinate plane during optical reconstruction.

[0068] Specifically, a target position can be assigned to each holographic image on the final two-dimensional reconstruction plane according to the complex amplitude distribution of the light field, so that the hologram embedded in each phase is placed in the corresponding pixel area of ​​the composite hologram (e.g., the complex amplitude distribution of the light field is: the first holographic image is placed in the upper left corner of the two-dimensional reconstruction plane, and the second holographic image is placed in the upper right corner of the two-dimensional reconstruction plane). Unassigned areas are filled with zero amplitude or zero phase to avoid overlap, thus obtaining a composite hologram.

[0069] In this embodiment of the invention, composite holograms can efficiently utilize the phase dimension to achieve spatial isolation of multiple information within a limited hologram area, display holograms of different polarization states, avoid regional overlap, improve the resolution and fidelity of holographic images, and obtain more accurate composite holograms.

[0070] S3. Extract the polarization field distribution corresponding to the composite hologram based on the complex amplitude distribution of the optical field in the composite hologram.

[0071] In this embodiment of the invention, the polarization of the light field with an embedded polarization state additional phase in the composite hologram is extracted, and the embedded additional phase information corresponding to the target polarization state is converted into the corresponding polarization light distribution. This accurately extracts the corresponding polarization state in the composite hologram, avoids multi-channel crosstalk problems, and improves the accuracy of subsequent optical reconstruction.

[0072] In this device, phase diffraction devices, after being modulated with different phase patterns, can emit light fields carrying different polarization states from the objective lens, that is, perform phase modulation on linearly polarized light.

[0073] Specifically, a preset polarization converter can be used to extract the independent polarization state of the light field corresponding to each hologram in the composite hologram, thereby obtaining the polarization light field distribution corresponding to the composite hologram.

[0074] This invention can extract the polarization field distribution corresponding to a composite hologram using the following polarization conversion formula:

[0075]

[0076] in, Indicates the distribution of polarized light field. Represents the imaginary number symbol, This represents the complex amplitude distribution of the light field in the composite hologram. Represents the generalized phase distribution. Indicates the convergence angle of the preset objective lens. This indicates the azimuth angle of the preset objective lens.

[0077] In detail, the polarization converter can be an artificial uniaxial crystal with locally varying optical axes, manufactured by a femtosecond laser that self-assembles nanostructures in quartz glass. It can reconstruct the incident polarization state of the light field of each hologram in the composite hologram, obtain the polarization light field distribution corresponding to the composite hologram, and realize the accurate extraction of the polarization state of the composite hologram.

[0078] S4. Optically reconstruct the composite hologram based on the polarization light field distribution to obtain the actual light field distribution.

[0079] In this embodiment of the invention, optical reconstruction involves Fourier transforming the light field of the composite hologram into the actual light field to obtain the actual light field distribution of the holographic image.

[0080] Specifically, optical reconstruction of the composite hologram based on the polarization field distribution to obtain the actual light field distribution includes: dividing the holographic light field of the composite hologram into polarization states based on the polarization field distribution to obtain circularly polarized states and other polarization states; and optical reconstruction of the composite hologram based on the circularly polarized states and other polarization states using a preset first optical reconstruction formula and a preset second optical reconstruction formula to obtain the actual light field distribution.

[0081] The preset first optical reconstruction formula is expressed as:

[0082]

[0083] in, Indicates the actual light field distribution. Represents the imaginary number symbol, Indicates the first Phase distribution of a holographic image, Indicates the first A preset first polarization phase factor for a holographic image Indicates the first A second polarization phase factor preset in a holographic image, Indicates the azimuth angle of the preset objective lens. Represents the generalized phase distribution. Indicates the convergence angle of the preset objective lens. This represents the corresponding right-handed circularly polarized state in the circularly polarized state. This represents the corresponding left-handed circularly polarized state in the circularly polarized state.

[0084] In this embodiment of the invention, when the circular polarization state includes both left-handed and right-handed circular polarization states, when the polarization state is left-handed circular polarization, When the polarization state is right-handed circular polarization, .

[0085] Furthermore, when the polarization state corresponding to the polarization field distribution is a linear polarization state or a vector polarization state, and other polarization states, the preset second optical reconstruction formula is expressed as:

[0086]

[0087]

[0088]

[0089]

[0090] in, Indicates the actual light field distribution. Represents the imaginary number symbol, Indicates the first Phase distribution of a holographic image, Indicates the first A preset first polarization phase factor for a holographic image Indicates the first A second polarization phase factor preset in a holographic image, Indicates the azimuth angle of the preset objective lens. Represents the generalized phase distribution. This indicates the convergence angle of the preset objective lens.

[0091] Specifically, This indicates the y-linear polarization state or radial polarization state among other polarization states. It represents the x-linear polarization state or angular polarization state among other polarization states.

[0092] In detail, the convergence angle of an objective lens refers to the angle between the marginal ray and the optical axis, which is mathematically equal to the half-aperture angle of the objective lens. The azimuth angle refers to the pointing angle of the ray (or the objective lens itself) in a plane perpendicular to the optical axis, usually with the x-axis as 0° and measured counterclockwise to 360°. The convergence angle and azimuth angle of the objective lens can determine the direction of the polarized light field distribution.

[0093] In detail, by polarizing the holographic light fields of different phases through the convergence angle and azimuth angle of the objective lens, the light fields of different polarization states can be transformed into spatially varying vector fields, thereby forming actual light field distributions with radial, spiral, or arbitrarily customized distributions.

[0094] In this embodiment of the invention, the optical reconstruction method of multiple holograms provided by the present invention can embed additional phase information corresponding to the target polarization state into multiple holograms respectively, and synthesize a single composite hologram, so that there are light fields of multiple holographic images in the same field of view, and extract the polarization light field distribution corresponding to the composite hologram. The additional phase information can be converted into the corresponding polarization state, overcome the multi-channel crosstalk problem, realize the dynamic real-time control of the polarization state of the holographic light field, and improve the accuracy of optical reconstruction in holographic imaging.

[0095] like Figure 4 The diagram shown is a functional block diagram of an optical reconstruction system based on multiple holograms provided in an embodiment of the present invention.

[0096] The optical reconstruction system 400 based on multiple holograms of the present invention can be installed in an electronic device. Depending on the functions implemented, the optical reconstruction system 400 based on multiple holograms may include a grayscale image conversion module 401, an additional phase embedding module 402, a polarization field distribution extraction module 403, and a sampling module 404. A module can also be called a unit, which refers to a series of computer program segments that can be executed by the processor of an electronic device and can perform a fixed function, and are stored in the memory of the electronic device.

[0097] In this embodiment, the functions of each module / unit are as follows:

[0098] The grayscale image conversion module 401 is used to acquire a target grayscale image set, convert each grayscale image in the grayscale image set into a holographic image, and obtain a holographic image set.

[0099] The additional phase embedding module 402 is used to perform additional phase embedding on the light field of each holographic image in the holographic image set to obtain a composite hologram.

[0100] The polarization field distribution extraction module 403 is used to extract the polarization field distribution corresponding to the composite hologram based on the light field phase distribution of the composite hologram.

[0101] The optical reconstruction module 404 is used to perform optical reconstruction of the composite hologram based on the polarization light field distribution to obtain the actual light field distribution.

[0102] In detail, each module in the multi-hologram-based optical reconstruction system 400 of this embodiment of the invention adopts the same characteristics as described above during use. Figure 1 The technique is the same as that used in the optical reconstruction method based on multiple holograms, and it can produce the same technical effect, so it will not be elaborated here.

[0103] An embodiment of the present invention provides an electronic device that implements an optical reconstruction method based on multiple holograms.

[0104] The electronic device may include a processor, memory, communication bus and communication interface, and may also include a computer program stored in memory and capable of running on the processor, such as a program for an optical reconstruction method based on multiple holograms.

[0105] In some embodiments, the processor may be composed of integrated circuits, such as a single packaged integrated circuit or multiple integrated circuits packaged with the same or different functions, including combinations of one or more central processing units (CPUs), microprocessors, digital processing chips, graphics processors, and various control chips.

[0106] The memory includes at least one type of readable storage medium, including flash memory, portable hard drives, multimedia cards, card-type memory (e.g., SD or DX memory), magnetic memory, magnetic disks, optical disks, etc. In some embodiments, the memory may be an internal storage unit of an electronic device, such as a portable hard drive of that electronic device.

[0107] The communication bus can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This bus can be divided into address bus, data bus, control bus, etc. The bus is configured to enable communication between memory and at least one processor.

[0108] The communication interface is used for communication between the aforementioned electronic device and other devices, including a network interface and a user interface. Optionally, the network interface may include a wired interface and / or a wireless interface (such as a Wi-Fi interface, Bluetooth interface, etc.), which is typically used to establish communication connections between the electronic device and other electronic devices. The user interface may be a display or an input unit (such as a keyboard). Optionally, the user interface may also be a standard wired interface or a wireless interface.

[0109] Specifically, the processor's implementation method for the above instructions can be found in the description of the relevant steps in the corresponding embodiments in the accompanying drawings, and will not be repeated here.

[0110] In the several embodiments provided by this invention, it should be understood that the disclosed devices, systems, and methods can be implemented in other ways. For example, the system embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and other division methods may be used in actual implementation.

[0111] The modules described as separate components may or may not be physically separate. The components shown as modules 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.

[0112] Furthermore, the functional modules in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or in the form of hardware plus software functional modules.

[0113] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0114] Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be embraced within the invention. No appended diagram markings in the claims should be construed as limiting the scope of the claims.

[0115] The embodiments of this application can acquire and process relevant data based on artificial intelligence technology. Artificial intelligence (AI) refers to the theories, methods, technologies, and application systems that use digital computers or machines controlled by digital computers to simulate, extend, and expand human intelligence, perceive the environment, acquire knowledge, and use that knowledge to obtain optimal results.

[0116] Furthermore, it is clear that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. Multiple units or systems stated in a system claim may also be implemented by a single unit or system through software or hardware. The terms "first," "second," etc., are used to indicate names and do not indicate any specific order.

[0117] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method of optical reconstruction based on multiple holograms, characterized in that, The method comprises: acquiring a target gray image set, converting each gray image in the gray image set into a holographic image to obtain a holographic image set; performing additional phase embedding on the light field of each holographic image in the holographic image set to obtain a composite holographic image; extracting a polarized light field distribution corresponding to the composite holographic image according to the light field phase distribution of the composite holographic image; performing optical reconstruction on the composite holographic image according to the polarized light field distribution to obtain an actual light field distribution.

2. The multi-hologram based optical reconstruction method of claim 1, wherein, The conversion of each gray image in the gray image set into a holographic image to obtain a holographic image set comprises: performing image size unification on each gray image to obtain a unified gray image, and mapping the gray value of the unified gray image into an amplitude distribution; performing amplitude replacement on a preset initial reconstruction plane according to the amplitude distribution to obtain an initial holographic image; performing iterative optimization on the phase of the initial holographic image to obtain a holographic image set.

3. The multi-hologram based optical reconstruction method of claim 1, wherein, The additional phase embedding on the light field of each holographic image in the holographic image set to obtain a composite holographic image comprises: acquiring a horizontal linearly polarized light corresponding to a preset excitation light; performing phase modulation on the horizontal linearly polarized light to obtain polarization phase information; performing additional phase embedding on the light field of each holographic image according to the polarization phase information by using a preset phase embedding formula to obtain a light field complex amplitude distribution; generating a composite holographic image corresponding to the holographic image set according to the light field complex amplitude distribution.

4. The multi-hologram based optical reconstruction method of claim 3, wherein, The phase embedding formula is represented as: wherein, represents the light field complex amplitude distribution, represents the taking of a phase operation, is the total number of holographic images, represents the amplitude of the th holographic image, represents the imaginary sign, represents the phase distribution of the th holographic image, represents the phase distribution in the polarization phase information.

5. The multi-hologram based optical reconstruction method of claim 1, wherein, The extraction of a polarized light field distribution corresponding to the composite holographic image according to the light field complex amplitude distribution of the composite holographic image comprises: extracting the independent polarization state of the light field of each holographic image in the composite holographic image by using a preset polarization conversion formula, wherein the polarization conversion formula is represented as: wherein represents a polarized light field distribution, represents an imaginary symbol, represents a light field complex amplitude distribution in a composite hologram, represents a generalized phase distribution, represents a convergence angle of a preset objective lens, represents an azimuth angle of a preset objective lens.

6. The multi-hologram based optical reconstruction method of claim 1, wherein, The optical reconstruction of the composite holographic image according to the polarized light field distribution to obtain an actual light field distribution comprises: performing polarization state division on the holographic light field of the composite holographic image according to the polarized light field distribution to obtain a circular polarization state and other polarization states; performing optical reconstruction on the composite holographic image according to the circular polarization state and the other polarization states by using a preset first optical reconstruction formula and a preset second optical reconstruction formula to obtain an actual light field distribution.

7. The multi-hologram based optical reconstruction method of claim 6, wherein, The first optical reconstruction formula is represented as: wherein denotes the actual light field distribution, denotes the imaginary sign, denotes the phase distribution of the holographic image, denotes the first polarization phase factor preset for the holographic image, denotes the second polarization phase factor preset for the holographic image, denotes the azimuth angle of the preset objective, denotes the generalized phase distribution, denotes the convergence angle of the preset objective, denotes the corresponding right-handed circular polarization state in the circular polarization state, denotes the corresponding left-handed circular polarization state in the circular polarization state; The preset second optical reconstruction formula is represented as: wherein represents the actual light field distribution, represents the imaginary sign, represents the phase distribution of the holographic image, represents the first polarization phase factor preset for the holographic image, represents the second polarization phase factor preset for the holographic image, represents the azimuth angle of the preset objective, represents the generalized phase distribution, represents the convergence angle of the preset objective.

8. A multi-hologram based optical reconstruction apparatus for implementing the optical reconstruction method as claimed in claim 3, characterized in that, It comprises: a laser for generating excitation light; a phase diffraction device for receiving the excitation light and performing additional phase embedding on the light field of a plurality of holographic images to obtain a composite holographic image; a polarization converter for extracting a polarized light field distribution of the composite holographic image; an objective lens for performing Fourier transformation on the polarized light field distribution to obtain an actual light field distribution; a charge-coupled device camera arranged at a back focal plane of the objective lens for generating an actual light field holographic image corresponding to the actual light field distribution according to the light field intensity information of the actual light field distribution.

9. The multi-hologram based optical reconstruction device of claim 8, wherein, The optical imaging system composed of two lenses with the same focal length is arranged between the phase diffraction device and the polarization converter, and is used for transmitting the light field of the complex hologram to the polarization converter.

10. The multi-hologram based optical reconstruction apparatus of claim 8, wherein, The phase diffraction device comprises a spatial light modulator, which is used for embedding the phase of the excitation light into the light field phase of the holographic image.

11. A multiple hologram based optical reconstruction system, characterized in that, The system comprises: A grayscale image conversion module is configured to obtain a target grayscale image set, convert each grayscale image in the grayscale image set into a holographic image, and obtain a holographic image set; An additional phase embedding module is configured to perform additional phase embedding on the light field of each holographic image in the holographic image set, and obtain a complex hologram; A polarized light field distribution extraction module is configured to extract a corresponding polarized light field distribution of the complex hologram according to the light field phase distribution of the complex hologram; An optical reconstruction module is configured to perform optical reconstruction on the complex hologram according to the polarized light field distribution, and obtain an actual light field distribution.

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