Design method for metasurface non-interlaced polarization multiplexing holographic display device

Abstract

The application discloses a design method for a metasurface non-interleaved polarization multiplexing holographic display device, phase analysis information is obtained by performing phase analysis on an initial detection polarization signal according to a phase recovery algorithm, an incident polarization light signal and an emitted polarization light signal are received, an emitted light complex amplitude is constructed, and corresponding analytical parameters of each position in the metasurface device are obtained by combining the phase analysis information; a corresponding structure-phase delay mapping is constructed according to scanning information obtained by scanning, and the analytical parameters are further matched and mapped to obtain corresponding mapping information; and microstructure geometric parameters of each position in the metasurface device are restored according to the mapping information, so that metasurface device design information is obtained. The design method can design a holographic display device capable of independently phase-controlling three arbitrary polarization states, thereby breaking through the limitation that a non-interleaved metasurface can only control orthogonal polarization states, and high spatial resolution display imaging and a larger imaging field of view can be realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metasurface devices, and particularly relates to a design method for a metasurface non-interleaved polarization multiplexing holographic display device. BACKGROUND

[0002] Holographic display technology has important application value in the fields of three-dimensional display, near-eye display, augmented reality (AR), virtual reality (VR), etc. With the development of nanotechnology, a two-dimensional metamaterial based on artificial microstructures, metasurface, is proposed. It is a two-dimensional planar material composed of subwavelength scale artificial microstructure units, which can realize flexible regulation of amplitude, phase and polarization characteristics of light waves at subwavelength scale by precisely designing the geometric shape, size and arrangement of the structure units. Due to its large field of view, high diffraction efficiency and high integration, metasurface provides support for the further development of holographic technology.

[0003] In order to further improve the performance and flexibility of metasurface holographic display, polarization multiplexing metasurface holographic display emerges as the times require. By controlling the polarization state of incident light and outgoing light, multiple independent holographic displays can be realized on the same metasurface. This design not only significantly improves the information capacity and functional integration of the metasurface, but also becomes one of the important development directions of metasurface holographic display technology.

[0004] However, the metasurface for multi-channel polarization multiplexing in the prior art mainly controls the same polarization and orthogonal polarization components in the orthogonal polarization independently, and does not have independent control ability for any polarization, resulting in insufficient polarization control ability. Although the interleaved metasurface realizes the multiplexing of multiple polarization states, it reduces the spatial resolution and field of view, and causes crosstalk, resulting in poor image quality of holographic imaging display. Therefore, the metasurface display device for multi-channel polarization multiplexing in the prior art has the problem of insufficient control ability. SUMMARY

[0005] The embodiments of the present application provide a design method for a metasurface non-interleaved polarization multiplexing holographic display device, which aims to solve the problem of insufficient control ability of the metasurface display device for multi-channel polarization multiplexing in the prior art method.

[0006] In a first aspect, the embodiments of the present application provide a design method for a metasurface non-interleaved polarization multiplexing holographic display device, wherein the design method is applied to a processing terminal of a design system, the processing terminal is in communication connection with a transmitter and a polarimeter to realize transmission of data information, a metasurface device is arranged between the transmitter and the polarimeter, and a microstructure layer in the metasurface device faces the polarimeter. The design method comprises the following steps:

[0007] According to a preset phase recovery algorithm, phase analysis is performed on an initial polarization analyzer obtained initial polarization signal to obtain corresponding phase analysis information, wherein the initial polarization signal includes image polarization signals corresponding to images of light signals in at least three different polarization states;

[0008] Receive incident polarized light signals from the transmitter and the exit polarized light signals of the polarization analyzer, and construct corresponding exit light complex amplitudes;

[0009] According to the phase analysis information, the exit light complex amplitudes are analyzed to obtain the analysis parameters corresponding to each position in the metasurface device;

[0010] According to the scanning information obtained by scanning the rectangular microstructure, a corresponding structure-phase delay mapping is constructed;

[0011] According to the preset mapping rule and the structure-phase delay mapping, the analysis parameters are matched and mapped to obtain corresponding mapping information;

[0012] According to the mapping information, the microstructure geometric parameters of each position in the metasurface device are restored to obtain corresponding metasurface device design information.

[0013] In a second aspect, the embodiments of the present application also provide a design system for a metasurface non-interleaved polarization multiplexing holographic display device, wherein the design system comprises a processing terminal, a transmitter and a polarization analyzer, the processing terminal is in communication connection with the transmitter and the polarization analyzer respectively to realize the transmission of data information, the metasurface device is arranged between the transmitter and the polarization analyzer, and the transmitter, the metasurface device and the polarization analyzer are arranged along the same optical axis in sequence;

[0014] The microstructure layer in the metasurface device faces the polarization analyzer;

[0015] The processing terminal is used to execute the design method for the metasurface non-interleaved polarization multiplexing holographic display device as described in the first aspect above.

[0016] The embodiment of the present application provides a design method and system for a metasurface non-interleaved polarization multiplexing holographic display device, phase analysis information is obtained by performing phase analysis on an initial detection polarization signal according to a phase recovery algorithm, an incident polarization light signal and an emitted polarization light signal are received to construct an emitted light complex amplitude, and the corresponding analytical parameters of each position in the metasurface device are obtained by combining the phase analysis information; a corresponding structure-phase delay mapping is constructed according to the scanning information obtained by scanning, and the analytical parameters are further matched and mapped to obtain corresponding mapping information; and the microstructure geometric parameters of each position in the metasurface device are restored according to the mapping information, so that metasurface device design information is obtained. The design method can design a holographic display device capable of independently phase-controlling three arbitrary polarization states, thereby breaking through the limitation that the non-interleaved metasurface can only control orthogonal polarization states; and high spatial resolution display imaging and a larger imaging field of view can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0018] Figure 1 The method flowchart of the design method for the metasurface non-interleaved polarization multiplexing holographic display device provided by the embodiment of the present application is provided.

[0019] Figure 2 The application scenario schematic diagram of the design method for the metasurface non-interleaved polarization multiplexing holographic display device provided by the embodiment of the present application is provided.

[0020] Figure 3 The phase analysis information in the design method for the metasurface non-interleaved polarization multiplexing holographic display device provided by the embodiment of the present application is provided.

[0021] Figure 4 The structure schematic diagram of the rectangular microstructure provided by the embodiment of the present application is provided.

[0022] Figure 5 The structure-phase delay mapping in the design method for the metasurface non-interleaved polarization multiplexing holographic display device provided by the embodiment of the present application is provided.

[0023] Figure 6 The analytical parameters in the design method for the metasurface non-interleaved polarization multiplexing holographic display device provided by the embodiment of the present application are provided.

[0024] Figure 7An application effect diagram of the design method for the metasurface non-interleaved polarization multiplexing holographic display device provided by the embodiment of the present application is shown in the figure;

[0025] Figure 8 A structural schematic diagram of the design system for the metasurface non-interleaved polarization multiplexing holographic display device provided by the embodiment of the present application is shown in the figure;

[0026] Figure 9 A schematic block diagram of the processing terminal provided by the embodiment of the present application is shown in the figure;

[0027] Figure 10 A schematic block diagram of the computer device provided by the embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0029] It should be understood that, when used in the specification and the appended claims, the terms "comprise" and "include" indicate the presence of the described features, integers, steps, operations, elements, and / or components, but do not exclude one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0030] It should also be understood that the terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the specification and the appended claims of the present application, the singular forms "a", "an" and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0031] It should be further understood that the term "and / or" used in the specification and the appended claims of the present application means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0032] Please refer to Figure 1 As shown in the figure, the embodiment of the present application provides a design method for a metasurface non-interleaved polarization multiplexing holographic display device, which is applied to a processing terminal 10, and the method is executed by application software installed in the processing terminal 10, as shown in the figure. Figure 2As shown, the processing terminal 10 is in communication connection with the transmitter 1 and the polarizer 2 respectively to realize the transmission of data information, the metasurface device 3 is arranged between the transmitter 1 and the polarizer 2, and the microstructure layer in the metasurface device 3 faces the polarizer 2; as Figure 2 As shown, the transmitter 1, the metasurface device 3 and the polarizer 2 are arranged in sequence along the same optical axis. The transmitter 1 can be an array light source with adjustable polarization direction, which is used to project incident light corresponding to the incident polarized light signal, the incident light is incident into the metasurface device 3 and output corresponding modulated light after being modulated by the metasurface device 3, and the polarizer 2 can perform polarization detection on the modulated light to obtain corresponding outgoing polarized light signal, and the modulated light can be imaged and displayed to obtain a display image. The processing terminal 10 analyzes and processes the incident polarized light signal and the outgoing polarized light signal to obtain corresponding metasurface device design information, and based on the metasurface device design information, the design of the metasurface device can be performed, so as to obtain a holographic display device with independent phase control for three arbitrary polarization states. The processing terminal 10 can be a terminal device with image analysis and data processing functions, such as a notebook computer, a desktop computer, a tablet computer or a mobile phone, etc. as Figure 1 As shown, the method comprises steps S110-S160.

[0033] S110, according to the preset phase recovery algorithm, the initial detection signal obtained by the polarizer is phase-analyzed to obtain corresponding phase analysis information.

[0034] The initial detection signal obtained by the polarizer can be phase-analyzed by the phase recovery algorithm, wherein the initial detection signal includes image detection signals corresponding to light signal images of at least three different polarization states; the light signal images of different polarization states are projected onto the metasurface device and are detected with the same polarization state as the incident light signal image to obtain corresponding image detection signals, where the metasurface device used here is an initial device that has not been finely adjusted according to the design information. Then, after each polarization state light signal image is modulated by the metasurface device, a group of image detection signals corresponding to the polarization state can be obtained, and the image detection signals of multiple polarization states are combined into the initial detection signal. By phase-analyzing the image detection signals of each polarization state in the initial detection signal, the corresponding phase analysis information can be obtained.

[0035] In a specific embodiment of the present application, as Figure 2As shown, the metasurface device can be irradiated with three polarized light signal images, wherein the incident light polarization state corresponding to the light signal image of the letter "Z" is "horizontal polarization", the incident light polarization state corresponding to the light signal image of the letter "J" is "45° polarization", and the incident light polarization state corresponding to the light signal image of the letter "U" is "left-handed circular polarization"; by detecting the polarization of the modulated light obtained after modulation with the same polarization state as the incident light, the corresponding image detection signal can be obtained, and the modulated light shows three different letters "Z", "J", and "U" at the target plane; in the current embodiment, the working wavelength of the metasurface device is set to 632 nm, and for this working wavelength, the material of the substrate layer 31 in the metasurface device is selected to be SiO2, and the material of the microstructure 32 is TiO2; the structural positional relationship between the substrate layer 31 and the microstructure 32 is as shown in Figure 4 .

[0036] In specific embodiments, the phase analysis information includes target phase distributions corresponding to each polarization state, step S110, including the sub-steps of: constructing a complex amplitude distribution corresponding to the image detection signal of each polarization state of the initial detection signal based on the basic phase distribution; performing frequency domain transformation on the complex amplitude distribution of each polarization state respectively to obtain a complex amplitude frequency domain distribution corresponding to each polarization state; correcting the complex amplitude frequency domain distribution of each polarization state according to the characteristic parameters of the metasurface device to obtain a corrected complex amplitude distribution corresponding to each polarization state; performing inverse transformation on each of the corrected complex amplitude distributions to obtain a spatial domain complex amplitude distribution corresponding to each polarization state; performing modulus replacement on each of the spatial domain complex amplitude distributions to obtain an updated complex amplitude distribution corresponding to each polarization state; determining whether the updated complex amplitude distribution of each polarization state and the corresponding complex amplitude distribution satisfy the convergence condition set in the phase recovery algorithm; if the updated complex amplitude distribution of the polarization state and the corresponding complex amplitude distribution satisfy the convergence condition, the phase part in the updated complex amplitude distribution is taken as the target phase distribution corresponding to the polarization state; if the updated complex amplitude distribution of the polarization state and the corresponding complex amplitude distribution do not satisfy the convergence condition, the updated complex amplitude distribution is taken as the complex amplitude distribution, and the step of performing frequency domain transformation on the complex amplitude distribution of each polarization state respectively to obtain a complex amplitude frequency domain distribution corresponding to each polarization state is returned. Wherein, the frequency domain transformation is Fourier transformation, and the inverse transformation is inverse Fourier transformation.

[0037] The phase analysis information includes target phase distributions corresponding to each polarization state, and in a specific embodiment, the target phase distributions corresponding to three polarization states are as shown in Figure 3 ; wherein φ 1 , φ 2 , φ 3These represent the phase angles corresponding to the three polarization states, while x and y correspond to the horizontal and vertical coordinate positions, respectively. The number of samples taken here is consistent with the number of microstructures contained in the microstructure layer of the metasurface device, which is 64×64.

[0038] Specifically, a complex amplitude distribution corresponding to the image polarization detection signal for each polarization state can be constructed based on the fundamental phase distribution. For each polarization state (horizontal polarization, 45° polarization, left-handed circular polarization), a fundamental phase distribution is assumed to exist, such as a phase distribution with all zeros. This fundamental phase distribution is then combined with the image polarization detection signal for a specific polarization state to construct the complex amplitude distribution corresponding to that polarization state. For example, the intensity distribution in the image polarization detection signal is set as follows: I m ( x , y The fundamental phase distribution is as follows: φ 0( x , y If )=0, then the initial complex amplitude distribution obtained by combination is as shown in formula (1):

[0039] (1);

[0040] For each polarization state, a frequency domain transformation is performed on the complex amplitude distribution, such as using Fourier transform, to convert the complex amplitude distribution into the corresponding complex amplitude frequency domain distribution. U 1( u , v (where u is the frequency and v is the amplitude), that is U 1( u , v )=F{ U 0( x , y )}, where F represents the two-dimensional Fourier transform operation, and i is the imaginary unit in the complex number.

[0041] Furthermore, the frequency domain distribution of complex amplitude for each polarization state is corrected based on the characteristic parameters of the metasurface device. Specifically, the frequency domain distribution of complex amplitude can be corrected based on the characteristic parameters. U 1( u , v Constraints can be imposed. For example, if the spectral characteristics of a metasurface device are known to have a certain limited range based on its operating wavelength, the complex amplitude frequency domain distribution can be determined based on the limited range corresponding to the spectral characteristics. U 1( u , v Spectral components outside this range are set to 0 or corrected to obtain the corrected complex amplitude distribution. U 2( u , v ).

[0042] Further, the modified complex amplitude distribution can be inverse transformed, for example, by inverse Fourier transform processing, to obtain a corresponding spatial domain complex amplitude distribution. The modified complex amplitude distribution U 2( u , v ) is two-dimensionally inverse Fourier transformed to obtain an updated spatial domain complex amplitude distribution U 3( x , y ), i.e. U 3( x , y ) = F −1 { U 2( u , v )}.

[0043] In the spatial domain complex amplitude distribution U 3( x , y ), the modulus of U 3( x , y ) is replaced by the square root of the intensity in the corresponding image detection signal, i.e. U 4( x , y )|= , while keeping its phase part, to obtain an updated updated complex amplitude distribution U 4( x , y ), and “||” is an absolute value operator.

[0044] It is determined whether the updated complex amplitude distribution of each polarization state and the corresponding complex amplitude distribution satisfy the convergence condition set in the phase recovery algorithm; for example, the phase difference between the updated complex amplitude distribution and the complex amplitude distribution before updating (such as obtaining the difference between the phases of the updated complex amplitude distribution and the complex amplitude distribution at each position and calculating the average value as the corresponding phase difference) can be calculated, and it is determined whether the phase difference is less than the phase threshold set in the convergence condition; if the phase difference is less than the phase threshold, it is determined that the convergence condition is satisfied; if the phase difference is not less than the phase threshold, it is determined that the convergence condition is not satisfied. If the convergence condition is satisfied, the phase part in the updated complex amplitude distribution is taken as the corresponding target phase distribution; if the convergence condition is not satisfied, the iterative updating process needs to be continued, at which time the updated complex amplitude distribution obtained at present can be taken as the initial complex amplitude distribution and the above-mentioned step of frequency domain transformation is executed, so that the above-mentioned phase updating process flow is executed again.

[0045] The above steps highlight the specific processing procedure for obtaining a set of target phase distributions by performing phase analysis on the image polarization detection signal of a certain polarization state. By performing phase analysis on the image polarization detection signal of each polarization state using the above method, the target phase distribution corresponding to each polarization state can be obtained.

[0046] S120: Receive the incident polarized light signal from the transmitter and the outgoing polarized light signal from the analyzer, and construct the corresponding outgoing light complex amplitude.

[0047] The transmitter emits incident light to the metasurface device based on the incident polarized light signal. The incident polarized light signal of the transmitter and the output polarized light signal of the analyzer can then be obtained. The complex amplitude of the output light can be constructed based on the incident polarized light signal and the output polarized light signal.

[0048] In a specific embodiment, step S120 includes the following sub-steps: constructing a corresponding incident polarization state matrix based on the incident polarized light signal; constructing a corresponding outgoing polarization state matrix based on the outgoing polarized light signal; and constructing the outgoing light complex amplitude based on the Jones matrix based on the incident polarization state matrix and the outgoing polarization state matrix.

[0049] The incident polarized light signal records the polarization state information of the incident light, and the emitted polarized light signal records the polarization state information of the emitted light; therefore, an incident polarization state matrix can be constructed based on the incident polarized light signal, and an emitted polarization state matrix can be constructed based on the emitted polarized light signal. For example, <α o β o | and |α i β i The incident polarization state matrices and the outgoing polarization state matrices are respectively the incident polarization state matrices and the outgoing polarization state matrices, which can be specifically expressed by formulas (2) and (3):

[0050] (2);

[0051] (3);

[0052] In formula (2), the subscript is the letter 'o'. Further, based on the incident polarization state matrix and the outgoing polarization state matrix, the complex amplitude of the outgoing light is constructed using the Jones matrix, where the Jones matrix can be expressed by formula (4):

[0053] (4);

[0054] When incident light of different polarization states interacts with the microstructure, and the outgoing light undergoes specific polarization analysis, the complex amplitude of the outgoing light obtained by constructing the corresponding structure according to the Jones matrix method can be expressed by formula (5):

[0055] (5).

[0056] S130, resolving the exit light complex amplitude according to the phase resolving information to obtain the resolving parameter corresponding to each position in the metasurface device.

[0057] Further resolving the exit light complex amplitude obtained by the above step according to the phase resolving information, thereby obtaining the resolving parameter corresponding to each position in the metasurface device.

[0058] In a specific embodiment, step S130 comprises the sub-steps: expanding the exit light complex amplitude to obtain a corresponding exit light complex amplitude expansion; obtaining an exit light phase expression corresponding to the exit light complex amplitude expansion; and simultaneously resolving the phase resolving information and the exit light phase expression to obtain the resolving parameter corresponding to each position in the metasurface device.

[0059] The complete expression of the exit light complex amplitude is shown in formula (6):

[0060] (6);

[0061] Wherein, the Jones matrix can be specifically expressed by formula (7):

[0062] (7);

[0063] Wherein, θ is the angle between the microstructure of the metasurface device and the reference plane, which matches the anisotropic direction of the microstructure (such as the angle between the long axis of the microstructure and the reference axis, which is aligned by a rotation matrix for analysis); R(θ) is a rotation matrix for describing the rotation of the coordinate system, wherein, , φ x , φ y correspond to the phase delay of the x and y directions, respectively.

[0064] The complex exponential in the above exit light complex amplitude can be expanded to obtain the corresponding exit light complex amplitude expansion, such as the complex exponential being e φ x +isin φ x ; the complex exponential in formula (7) can be expanded in a similar manner, and the same items are combined to separate the real part Re( E o ) and the imaginary part Im( E o ), to obtain: E o =Re( Eo )+ i ⋅Im( E o By doing so, we can obtain the expansion formula of the complex amplitude of the emitted light corresponding to the complex amplitude of the emitted light.

[0065] Based on the above complex amplitude expansion of the emitted light, the phase expression of the emitted light is further obtained, complex number E o Argument φ o (i.e., the phase of the emitted light) satisfies: φ o = arg(E o )=arctan This formula is the phase expression for the emitted light. When obtaining the phase expression for the emitted light, it is important to determine the quadrant; if Re( E o If )>0, directly use arctan(Im / Re); if Re( E o If ) < 0, then it needs to be added π Correction; if Re( E o If )=0, then it is π / 2 or 3 π / 2 (determined according to the correspondence between the positive and negative imaginary parts). φ o The physical meaning of phase is: φ o It describes the "time delay" or "spatial phase distribution" of the outgoing light vibration, reflecting the phase modulation of the light field by the metasurface (such as the phase singularity of vortex light, wavefront modulation of holographic imaging, etc.).

[0066] By simultaneously analyzing the phase resolution information and the emitted light phase expression, the analytical parameters corresponding to each location in the metasurface device can be obtained. Specifically, the phase resolution information includes the target phase distribution corresponding to at least three polarization states, and the emitted light phase expression includes... φ x , φ x Given the three unknowns—including the rotation angle θ—these unknowns can be analyzed by simultaneously solving the equations for the phase distributions of at least three targets and the phase of the emitted light. This allows us to obtain the microstructure required for each location (with x and y as the horizontal and vertical coordinates) within the metasurface device. φ x , φ x The phase delay (where the subscript x represents the x-axis polarization direction and the subscript y represents the y-axis polarization direction) and the rotation angle θ are used as analytical parameters for the metasurface device. The obtained analytical parameters are as follows:Figure 6 as shown.

[0067] S140, constructing a structure-phase delay mapping according to the scanning information obtained by scanning the rectangular microstructure.

[0068] The length and width of the rectangular microstructure are scanned to obtain corresponding scanning information, and the structure-phase delay mapping is constructed based on the scanning information, so as to reflect the phase delay of the microstructure with different geometric sizes under x and y polarizations.

[0069] In a specific embodiment, step S140 includes the following sub-steps: performing finite-difference time-domain analysis calculation according to the characteristic parameters of the metasurface device and the scanning information to obtain a corresponding phase response; and performing position matching mapping according to the structure parameters in the scanning information and the phase response to construct a corresponding structure-phase delay mapping based on the same position.

[0070] In addition to the operating wavelength, the characteristic parameters of the metasurface device also include height H and period P. In the case of fixed height H and fixed period P of the rectangular microstructure, the above characteristic parameters and the obtained scanning information can be analyzed and calculated by using the finite-difference time-domain method (FDTD), so as to obtain a corresponding phase response. For example, the height H can be set to 700 nm, and the period P can be set to 400 nm.

[0071] As in a specific embodiment, based on fixed H and period P, the scanned rectangular microstructure length range L is 100-400 nm and the scanned rectangular microstructure width range W is 100-400 nm, and the corresponding phase responses of L and W are calculated by using the finite-difference time-domain method. φ xreal and φ yreal The empirical formula (such as a quadratic function) fitted according to the finite-difference time-domain method is: φ xreal =a 1 L²+b 1 L+c 1 W²+d 1 W+e 1 ; φ yreal =a 2 L²+b 2 L+c 2 W²+d 2 W+e2 . wherein, a 1 、b 1 、 c 1 … e 2 are the coefficient values in the fitting formula, which vary with the material of the microstructure, the working wavelength, and the height H.

[0072] According to the position matching mapping of the structure parameters at the same position in the scanning information and the phase response corresponding to the position, a structure-phase delay mapping is constructed based on the same position correspondence, and the obtained structure-phase delay mapping is as shown in Figure 5 .

[0073] In step S150, the analysis parameters are matched and mapped according to the preset mapping rule and the structure-phase delay mapping to obtain corresponding mapping information.

[0074] According to the mapping rule and the structure-phase delay mapping obtained in the above steps, the analysis parameters are matched and mapped to obtain mapping information corresponding to the analysis parameters.

[0075] In a specific embodiment, step S150 includes a sub-step of constructing an error function corresponding to the analysis parameters and the structure-phase delay mapping according to the mapping rule; and obtaining, as the mapping information, the microstructure parameters in the structure-phase delay mapping corresponding to the minimum error value of the error function according to the analysis parameters.

[0076] Specifically, an error function corresponding to the analysis parameters and the structure-phase delay mapping can be constructed according to the mapping rule, for example, the error function can be set as FOM = min[∑(|R(x, y) - R'(x, y)| + |R'(x, y) - R''(x, y)| + |R''(x, y) - R'''(x, y)| + |R'''(x, y) - R''''(x, y)| + |R''''(x, y) - R'''''(x, y)| + |R'''''(x, y) - R''''''(x, y)| + |R''''''(x, y) - R'''''')(x, y)| + |R'''''')(x, y) - R'''')(x, y)| + |R'''')(x, y) - R''')(x, y)| + |R''')(x, y) - R'(x, y)| + |R'(x, y) - R(x, y)|)], where FOM is an error value calculated based on the error function, ∑ is an accumulation calculation symbol, φ xreal - φ x |+| φ yreal - φ y |)]. φ xreal R(x, y) is a real phase response corresponding to the x-axis polarization direction in the structure-phase delay mapping at different positions, φ yreal R'(x, y) is a real phase response corresponding to the y-axis polarization direction in the structure-phase delay mapping at different positions, φ x R'(x, y) is a real phase response corresponding to the y-axis polarization direction in the structure-phase delay mapping at different positions, φ yTo analyze the demand phase response of different positions in the parameter corresponding to the y-axis polarization direction.

[0077] According to the minimum error value of the error function corresponding to the demand phase response of each position in the analysis parameter, the structure-phase delay mapping is obtained at the corresponding microstructure parameter, as the mapping information; the mapping information contains the microstructure size corresponding to each microstructure (such as the microstructure layer in the specific embodiment contains 64x64 microstructures).

[0078] S160, according to the mapping information, the microstructure geometric parameters of each position in the metasurface device are restored, and the corresponding metasurface device design information is obtained.

[0079] According to the microstructure size in the mapping information, the microstructure geometric parameters of each position in the metasurface device are restored, and the metasurface device design information containing the position microstructure geometric parameters is obtained, so as to construct the geometric structure of the entire microstructure layer based on the design information. According to the metasurface device design information, the metasurface device meeting the corresponding regulation and control demand can be actually manufactured, and independent phase regulation and control of three arbitrary polarization states can be realized; that is, independent phase regulation and control of three arbitrary polarizations (such as horizontal polarization, 45° polarization, and left circular polarization) can be realized, so as to realize the holographic display function of different patterns.

[0080] In a specific embodiment, the metasurface device is processed according to the obtained metasurface device design information, and the pattern obtained in the far field under the specified polarization combination is as shown in Figure 7 It can be seen from Figure 7 that the three letters can be clearly displayed, and there is no crosstalk between the letters, proving the reliability and practical application effect of the above design method. The metasurface device designed by the above design method can be applied to multiple wavebands such as ultraviolet, visible light, near-infrared, and mid-infrared.

[0081] The design method for the metasurface non-interleaved polarization multiplexing holographic display device disclosed in the above embodiment obtains phase analysis information by performing phase analysis on the initial detection polarization signal according to the phase recovery algorithm, receives the incident polarization light signal and the emitted polarization light signal to construct the emitted light complex amplitude, and obtains the analysis parameter corresponding to each position in the metasurface device by combining the phase analysis information; the corresponding structure-phase delay mapping is constructed according to the scanning information obtained by scanning, and the analysis parameter is further matched and mapped to obtain the corresponding mapping information; the microstructure geometric parameters of each position in the metasurface device are restored according to the mapping information, and the metasurface device design information is obtained. The above design method can design a holographic display device that can realize independent phase regulation and control of three arbitrary polarization states, breaking through the limitation of non-interleaved metasurface that can only regulate orthogonal polarization states; and can realize high spatial resolution display imaging and larger imaging field of view.

[0082] This invention also provides a design system for metasurface non-interlaced polarization multiplexing holographic display devices, such as... Figure 8 As shown, the design system includes a processing terminal 10, a transmitter 1, and an analyzer 2. The processing terminal 10 is communicatively connected to both the transmitter 1 and the analyzer 2 to transmit data. A metasurface device 3 is disposed between the transmitter 1 and the analyzer 2, and the transmitter 1, the metasurface device 3, and the analyzer 2 are arranged sequentially along the same optical axis. The microstructure layer in the metasurface device 3 faces the analyzer 2. The processing terminal 10 is used to execute any embodiment of the aforementioned design method for a metasurface non-interlaced polarization multiplexing holographic display device. Specifically, please refer to... Figure 2 and Figure 4 , Figure 2 This is a schematic diagram illustrating an application scenario of the design method for a metasurface non-interlaced polarization multiplexing holographic display device provided in an embodiment of the present invention. Figure 4 A schematic diagram of the rectangular microstructure provided in an embodiment of the present invention.

[0083] Specifically, the metasurface device 3 consists of a substrate layer 31 and a microstructure 32. The substrate layer can be made of a material that is completely transmissive to the operating wavelength, with a refractive index lower than that of the microstructure material. The thickness of the substrate can be adjusted according to specific requirements, and can be any value from 0.2 mm to 3 mm. The microstructure 32 contains a microstructure layer, which is composed of multiple microstructures arranged in a matrix. The phase distribution of the metasurface can be changed by the type, size, and arrangement of the microstructures, with a phase variation range of 0-2π. There are gaps between the microstructures in the microstructure layer, which can be filled with a material with a refractive index lower than that of the microstructure to protect it. The microstructure material can be amorphous silicon, polycrystalline silicon, silicon nitride, titanium dioxide, gallium nitride, or chalcogenides, depending on the operating wavelength.

[0084] The microstructures in the microstructure layer can be either nano-rectangular pillars or nano-rectangular pores, and the arrangement of the microstructures can be periodic structures such as tetragonal arrangement and hexagonal arrangement or other quasicrystalline arrangement.

[0085] like Figure 9As shown, the following units are specifically configured in the processing terminal 10: a phase analysis unit 110, configured to perform phase analysis on an initial polarization analyzer obtained initial polarization signal according to a preset phase recovery algorithm to obtain corresponding phase analysis information, the initial polarization analyzer obtained initial polarization signal including image polarization signals corresponding to light signals images of at least three different polarization states; a construction unit 120, configured to receive incident polarized light signals from the transmitter and outgoing polarized light signals from the polarization analyzer and construct corresponding outgoing light complex amplitudes; an analysis parameter acquisition unit 130, configured to analyze the outgoing light complex amplitudes according to the phase analysis information to obtain analysis parameters corresponding to each position in the metasurface device; a mapping construction unit 140, configured to construct a corresponding structure-phase delay mapping according to scanning information obtained by scanning the rectangular microstructure; a matching mapping unit 150, configured to match map the analysis parameters according to a preset mapping rule and the structure-phase delay mapping to obtain corresponding mapping information; and a parameter restoration unit 160, configured to restore the microstructure geometric parameters of each position in the metasurface device according to the mapping information to obtain corresponding metasurface device design information.

[0086] In a more specific embodiment, the microstructure layer in the metasurface device is composed of a microstructure array; the gap between the microstructure array is protected by a filling material, and the refractive index of the filling material is lower than the material refractive index of the microstructure array; and the material of the microstructure array is amorphous silicon, polycrystalline silicon, silicon nitride, titanium dioxide, gallium nitride or a chalcogenide compound.

[0087] In the design system for the metasurface non-interleaved polarization multiplexing holographic display device provided in the embodiments of the present application, the above-mentioned design method for the metasurface non-interleaved polarization multiplexing holographic display device is applied, the phase analysis information is obtained by performing phase analysis on the initial polarization signal according to the phase recovery algorithm, the outgoing light complex amplitudes are constructed by receiving the incident polarized light signals and the outgoing polarized light signals, and the analysis parameters corresponding to each position in the metasurface device are obtained in combination with the phase analysis information; the structure-phase delay mapping is constructed according to the scanning information obtained by scanning, and the matching mapping is further performed on the analysis parameters to obtain the corresponding mapping information; and the microstructure geometric parameters of each position in the metasurface device are restored according to the mapping information to obtain the metasurface device design information. The above-mentioned design method can design a holographic display device that can independently phase control three arbitrary polarization states, breaking through the limitation that the non-interleaved metasurface can only control orthogonal polarization states; and can realize high spatial resolution display imaging and a larger imaging field of view.

[0088] The virtual units configured in the processing terminal 10 can be realized in the form of a computer program, which can run on a computer device as shown. Figure 10

[0089] ​Please refer to Figure 10 , Figure 10 is a schematic block diagram of a computer device provided by an embodiment of the present application. The computer device can be a processing terminal 10 for performing a design method for a metasurface non-staggered polarization multiplexing holographic display device to obtain metasurface device design information.

[0090] Please refer to Figure 10 , the computer device 500 includes a processor 502, a memory and a communication interface 505 connected through a communication bus 501, wherein the memory can include a storage medium 503 and an internal memory 504.

[0091] The storage medium 503 can store an operating system 5031 and a computer program 5032. The computer program 5032, when executed, can cause the processor 502 to perform a design method for a metasurface non-staggered polarization multiplexing holographic display device, wherein the storage medium 503 can be a volatile storage medium or a non-volatile storage medium.

[0092] The processor 502 is configured to provide computing and control capabilities to support the operation of the entire computer device 500.

[0093] The internal memory 504 provides an environment for the execution of the computer program 5032 in the storage medium 503, and the computer program 5032, when executed by the processor 502, can cause the processor 502 to perform a design method for a metasurface non-staggered polarization multiplexing holographic display device.

[0094] The communication interface 505 is configured to perform network communication, such as providing transmission of data information, etc. Those skilled in the art can understand that Figure 10 The structure shown in the figure is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the computer device 500 to which the scheme of the present application is applied. The specific computer device 500 can include more or fewer components than those shown in the figure, or combine certain components, or have a different component arrangement.

[0095] The processor 502 is configured to run the computer program 5032 stored in the memory to implement the corresponding functions in the above-mentioned design method for a metasurface non-staggered polarization multiplexing holographic display device.

[0096] Those skilled in the art can understand that Figure 10 The embodiments of the computer device shown in the figure do not constitute a limitation on the specific structure of the computer device. In other embodiments, the computer device can include more or fewer components than those shown in the figure, or combine certain components, or have a different component arrangement. For example, in some embodiments, the computer device can only include a memory and a processor, and in such embodiments, the structure and function of the memory and the processor are the same asFigure 10 The embodiments shown are consistent with each other and will not be described again.

[0097] It should be understood that, in the embodiments of the present application, the processor 502 can be a central processing unit (CPU), and the processor 502 can also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, and the like. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor.

[0098] In another embodiment of the present application, a computer readable storage medium is provided. The computer readable storage medium can be a volatile or non-volatile computer readable storage medium. The computer readable storage medium stores a computer program, wherein the computer program is executed by a processor to implement the steps contained in the above-mentioned design method for a metasurface non-interleaved polarization multiplexing holographic display device.

[0099] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-mentioned devices, apparatuses and units can refer to the corresponding processes in the foregoing method embodiments, which will not be described again. Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized by electronic hardware, computer software or a combination of both. In order to clearly illustrate the interchangeability of hardware and software, the components and steps of each example have been described in the above description in a general manner. Whether the functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0100] In several embodiments provided by the present application, it should be understood that the disclosed devices, apparatuses and methods can be implemented in other manners. For example, the embodiments of the apparatus described above are merely schematic. For example, the division of the units is only a logical function division. There can be another division manner for the actual implementation, or a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between the units can be indirect couplings or communication connections through some interfaces, devices or units, and can be electric, mechanical or in other forms.

[0101] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e., can be located in one place, or can be distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiments of the present application.

[0102] In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically, or two or more units can be integrated into one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0103] The integrated unit, if realized in the form of a software functional unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the part of the prior art that contributes to the technical solutions, or all or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a computer readable storage medium, and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the embodiments of the present application. The aforementioned computer readable storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a magnetic disk or an optical disk, and various media that can store program codes.

[0104] The above description is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of various equivalent modifications or replacements within the technical range disclosed by the present application, and these modifications or replacements should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A design method for a metasurface non-interleaved polarization multiplexed holographic display device, characterized in that, The design method is applied to a processing terminal of a design system, the processing terminal is in communication connection with a transmitter and an analyzer to realize transmission of data information, a metasurface device is arranged between the transmitter and the analyzer, and a microstructure layer in the metasurface device faces the analyzer, and the design method comprises: phase analysis is performed on an initial analyzer signal obtained by the analyzer according to a preset phase recovery algorithm to obtain corresponding phase analysis information, the initial analyzer signal comprises image analyzer signals corresponding to images of light signals in at least three different polarization states; incident polarized light signals from the transmitter and emergent polarized light signals from the analyzer are received and corresponding emergent light complex amplitudes are constructed; the emergent light complex amplitudes are analyzed according to the phase analysis information to obtain analysis parameters corresponding to positions in the metasurface device; structure-phase delay mapping corresponding to scanning information obtained by scanning a rectangular microstructure is constructed; the analysis parameters are matched and mapped according to a preset mapping rule and the structure-phase delay mapping to obtain corresponding mapping information; microstructure geometric parameters of the positions in the metasurface device are restored according to the mapping information to obtain corresponding metasurface device design information.

2. The method of designing for a metasurface non-interleaved polarization multiplexed holographic display device of claim 1, wherein, The phase analysis information comprises target phase distributions corresponding to the polarization states; the phase analysis is performed on the initial analyzer signal obtained by the analyzer according to the preset phase recovery algorithm to obtain the corresponding phase analysis information, and the phase analysis comprises: complex amplitude distributions corresponding to the image analyzer signals of the initial analyzer signal in the polarization states are constructed based on a basic phase distribution; frequency domain transformation is respectively performed on the complex amplitude distributions in the polarization states to obtain complex amplitude frequency domain distributions corresponding to the polarization states; the complex amplitude frequency domain distributions in the polarization states are corrected according to characteristic parameters of the metasurface device to obtain corrected complex amplitude distributions corresponding to the polarization states; inverse transformation is performed on the corrected complex amplitude distributions to obtain spatial domain complex amplitude distributions corresponding to the polarization states; modulus replacement is performed on the spatial domain complex amplitude distributions to update the updated complex amplitude distributions corresponding to the polarization states; it is judged whether the updated complex amplitude distributions in the polarization states and the corresponding complex amplitude distributions satisfy a convergence condition set in the phase recovery algorithm; if the updated complex amplitude distributions in the polarization states and the corresponding complex amplitude distributions satisfy the convergence condition, phase parts in the updated complex amplitude distributions are taken as the target phase distributions corresponding to the polarization states; if the updated complex amplitude distributions in the polarization states and the corresponding complex amplitude distributions do not satisfy the convergence condition, the updated complex amplitude distributions are taken as the complex amplitude distributions, and the step of performing the frequency domain transformation on the complex amplitude distributions in the polarization states to obtain the complex amplitude frequency domain distributions corresponding to the polarization states is performed again.

3. The method of designing for a metasurface non-interleaved polarization multiplexed holographic display device of claim 2, wherein, The frequency domain transformation is Fourier transformation, and the inverse transformation is inverse Fourier transformation.

4. The method of designing for a metasurface non-interleaved polarization multiplexed holographic display device according to any one of claims 1-3, wherein, The incident polarized light signals from the transmitter and the emergent polarized light signals from the analyzer are received and the corresponding emergent light complex amplitudes are constructed, and the receiving comprises: a polarization state matrix corresponding to the incident polarized light signals is constructed. constructing a corresponding exit polarization state matrix according to the exit polarized light signal; constructing an exit light complex amplitude based on a Jones matrix according to the incident polarization state matrix and the exit polarization state matrix.

5. The method of designing for a metasurface non-interleaved polarization multiplexed holographic display device according to any one of claims 1-3, wherein, the exit light complex amplitude is analyzed according to the phase analysis information to obtain an analysis parameter corresponding to each position in the metasurface device, including: the exit light complex amplitude is unfolded to obtain a corresponding exit light complex amplitude unfolding expression; an exit light phase expression corresponding to the exit light complex amplitude unfolding expression is obtained; the phase analysis information and the exit light phase expression are simultaneously analyzed to obtain the analysis parameter corresponding to each position in the metasurface device.

6. The method of designing for a metasurface non-interleaved polarization multiplexed holographic display device according to any one of claims 1-3, wherein, the structure-phase delay mapping is constructed according to the scanning information obtained by scanning the rectangular microstructure, including: a corresponding phase response is obtained by performing a finite difference time domain analysis calculation according to the characteristic parameters of the metasurface device and the scanning information; position matching mapping is performed according to the structure parameters in the scanning information and the phase response, so as to construct the corresponding structure-phase delay mapping based on the same position.

7. The method of designing for a metasurface non-interleaved polarization multiplexed holographic display device according to any one of claims 1-3, wherein, the analysis parameter is matched and mapped according to the preset mapping rule and the structure-phase delay mapping to obtain the corresponding mapping information, including: an error function corresponding to the analysis parameter and the structure-phase delay mapping is constructed according to the mapping rule; when the error value of the error function is the smallest, the microstructure parameter corresponding to the structure-phase delay mapping is taken as the mapping information.

8. A design system for a metasurface non-interlaced polarization multiplexed holographic display device, characterized in that, The design system includes a processing terminal, a transmitter and a polarizer, the processing terminal is in communication connection with the transmitter and the polarizer to realize the transmission of data information, the metasurface device is arranged between the transmitter and the polarizer, and the transmitter, the metasurface device and the polarizer are arranged in sequence along the same optical axis; The microstructure layer in the metasurface device faces the polarizer. The processing terminal is used to execute the design method for the metasurface non-interleaved polarization multiplexing holographic display device according to any one of claims 1-7.

9. The design system for a metasurface non-interlaced polarization multiplexed holographic display device of claim 8, wherein, The system further includes units arranged in the processing terminal: a phase analysis unit for performing phase analysis on an initial detection signal obtained by the polarizer according to a preset phase recovery algorithm to obtain corresponding phase analysis information, the initial detection signal including image detection signals corresponding to light signal images of at least three different polarization states; a construction unit for receiving incident polarized light signals from the transmitter and exit polarized light signals from the polarizer and constructing corresponding exit light complex amplitudes; an analysis parameter acquisition unit for analyzing the exit light complex amplitude according to the phase analysis information to obtain an analysis parameter corresponding to each position in the metasurface device; a mapping construction unit for constructing a corresponding structure-phase delay mapping according to scanning information obtained by scanning the rectangular microstructure; a matching mapping unit for matching and mapping the analysis parameter according to a preset mapping rule and the structure-phase delay mapping to obtain corresponding mapping information; A parameter restoring unit is configured to restore the microstructure geometric parameters of each position in the metasurface device according to the mapping information, to obtain corresponding metasurface device design information.

10. The design system for a metasurface non-interlaced polarization multiplexed holographic display device of claim 9, wherein, The microstructure layer in the metasurface device is composed of a microstructure array; The gap between the microstructure arrays is protected by a filling material, and the refractive index of the filling material is lower than the refractive index of the material of the microstructure array; the material of the microstructure array is amorphous silicon, polycrystalline silicon, silicon nitride, titanium dioxide, gallium nitride or a chalcogenide compound.

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