A programmable metasurface optical modulation method and system

Abstract

This invention relates to the field of beam control, specifically to a programmable metasurface optical modulation method and system. The method involves constructing programmable metasurface units, assembling several programmable metasurface units into a programmable metasurface array, constructing an integrated pixel-level addressable thin-film transistor array corresponding to the programmable metasurface array, and applying variable electrical pulses to the programmable metasurface units. A phase-change material state-optical response database is constructed. Based on the database and the target light field, the required driving signal for each programmable metasurface unit within the programmable metasurface array is determined. Based on the driving signal, the thin-film transistor array is controlled to apply electrical pulses, thereby outputting a dynamically shaped light field. This invention utilizes phase-change materials and nanomaterials to construct programmable metasurface units, enabling the switching of different complex light field patterns within milliseconds, achieving "multi-purpose functionality," and realizing synchronous and independent control of beam phase, amplitude, and polarization. It can withstand high laser power and reduce device size.

Description

Technical Field

[0001] This invention relates to the field of beam control, and more particularly to a programmable metasurface optical modulation method and system. Background Technology

[0002] Beam shaping technology is widely used in high-power laser processing, lidar, optical trapping, and advanced imaging. Traditional static beam shaping elements, such as diffractive optical elements or fixed-phase plates, cannot change their output light field after processing, lacking flexibility. Dynamic beam shaping elements, such as liquid crystal-based spatial light modulators, can adjust the phase, but suffer from limited resolution, low damage threshold, and large size. Existing technologies have emerged that utilize metasurfaces to achieve miniaturized beam shaping; however, most current metasurface beam shaping devices are static. Although research has attempted to adjust metasurface beam shaping devices by changing temperature or mechanical stretching, the adjustment speed is slow, the adjustment range is limited, and complex multi-parameter coordinated control is difficult to achieve. Therefore, there is an urgent need for a fast, multi-dimensional, and programmable dynamic beam shaping solution in a compact structure. Summary of the Invention

[0003] Considering that existing metasurface beam shaping devices have slow adjustment speeds, limited adjustment ranges, and difficulty in achieving complex multi-parameter coordinated control, they cannot achieve rapid switching of different optical field distributions or synchronous independent control of beam phase, amplitude, and polarization. This invention provides a programmable metasurface optical modulation method, which includes the following steps:

[0004] S100: Construct a programmable metasurface unit, and assemble a programmable metasurface array from several programmable metasurface units; wherein, the programmable metasurface unit contains a phase change material and a nanomaterial, and the phase change material is capable of reversible changes between crystalline and amorphous states;

[0005] S200: Construct an integrated pixel-level addressable thin-film transistor array corresponding to the programmable metasurface array, thereby applying variable electrical pulses to the programmable metasurface unit;

[0006] S300: Constructing a phase change material state-optical response database;

[0007] S400: Based on the database and the target light field, determine the driving signal required for each programmable metasurface unit in the programmable metasurface array; based on the driving signal, control the thin-film transistor array to apply an electrical pulse, thereby outputting a dynamically shaped light field.

[0008] Preferably, in S100, programmable metasurface units are constructed, and a programmable metasurface array is formed by combining several programmable metasurface units, specifically as follows:

[0009] A phase change material layer is formed, and transparent electrodes are respectively disposed on both sides of the phase change material layer; an anisotropic dielectric nanopillar is formed on one of the transparent electrodes to construct a programmable metasurface unit.

[0010] n n programmable metasurface units are arranged in an array to form a programmable metasurface array.

[0011] Preferably, in S200, an integrated pixel-level addressable thin-film transistor array corresponding to the programmable metasurface array is constructed to apply variable electrical pulses to the programmable metasurface unit, specifically as follows:

[0012] Each programmable metasurface unit within the programmable metasurface array is individually equipped with an independently addressable drive circuit, thereby enabling n n driving circuits form an integrated pixel-level addressable thin-film transistor array; each driving circuit applies a variable electrical pulse to its corresponding programmable metasurface unit, thereby reversibly changing the physical state of the programmable metasurface unit.

[0013] Preferably, in S300, a phase change material state-optical response database is constructed, specifically as follows:

[0014] Based on the ratio of crystalline to amorphous state changes of the phase change material under different electric pulses, the optical property changes of the programmable metasurface unit are determined; based on the changes in optical properties, a phase change material state-optical response database is constructed; wherein, the optical properties include at least one of phase, amplitude, and polarization.

[0015] Preferably, in S400, based on the database and the target light field, the required driving signal for each programmable metasurface unit in the programmable metasurface array is determined; based on the driving signal, the thin-film transistor array is controlled to apply electrical pulses, thereby outputting a dynamically shaped light field, specifically as follows:

[0016] Based on the database and the target light field, the phase / amplitude distribution of the programmable metasurface array is set, and the output light field of the programmable metasurface array is determined by forward propagation.

[0017] Based on the deviation between the output light field and the target light field, determine whether the preset conditions are met;

[0018] If satisfied, then based on the current phase / amplitude distribution of the programmable metasurface array, determine the driving signal required for each programmable metasurface unit in the programmable metasurface array;

[0019] If the conditions are not met, the phase / amplitude distribution of the programmable metasurface array is updated by back propagation, and the output light field of the programmable metasurface array is determined by forward propagation until the preset conditions are met.

[0020] The driving signal is sent to the FPGA control driver to control the state of each independently addressable driving circuit in the thin-film transistor array, and to apply electrical pulses to the programmable metasurface array during the incident beam, thereby outputting a dynamically shaped light field.

[0021] On the other hand, the present invention provides a programmable metasurface optical modulation system, the system comprising:

[0022] A programmable metasurface array includes several programmable metasurface units; wherein, the programmable metasurface units contain phase change materials and nanomaterials, and the phase change materials are capable of reversibly changing between crystalline and amorphous states;

[0023] An integrated pixel-level addressable thin-film transistor array is used to apply variable electrical pulses to the programmable metasurface unit;

[0024] Database building module, used to build a phase change material state-optical response database;

[0025] A drive signal determination module is used to determine the drive signal required for each programmable metasurface unit in the programmable metasurface array based on the database and the target light field.

[0026] The control module is used to control the thin-film transistor array to apply electrical pulses according to the driving signal, thereby outputting a dynamically shaped light field.

[0027] Preferably, the programmable metasurface unit includes forming a phase change material layer, with transparent electrodes disposed on both sides of the phase change material layer; an anisotropic dielectric nanopillar is formed on one of the transparent electrodes.

[0028] The programmable metasurface array consists of n It consists of an array of n programmable metasurface units.

[0029] Preferably, the integrated pixel-level addressable thin-film transistor array includes n n individually configured and independently addressable drive circuits; each drive circuit corresponds one-to-one with a programmable metasurface unit;

[0030] Each driving circuit applies a variable electrical pulse to its corresponding programmable metasurface unit, thereby reversibly changing the physical state of the programmable metasurface unit.

[0031] Preferably, the database construction module is used to construct a phase change material state-optical response database, specifically:

[0032] Based on the ratio of crystalline to amorphous state changes of the phase change material under different electric pulses, the optical property changes of the programmable metasurface unit are determined; based on the changes in optical properties, a phase change material state-optical response database is constructed; wherein, the optical properties include at least one of phase, amplitude, and polarization.

[0033] Preferably, the driving signal determination module is used to determine the driving signal required for each programmable metasurface unit in the programmable metasurface array based on the database and the target light field, specifically as follows:

[0034] Based on the database and the target light field, the phase / amplitude distribution of the programmable metasurface array is set, and the output light field of the programmable metasurface array is determined by forward propagation.

[0035] Based on the deviation between the output light field and the target light field, determine whether the preset conditions are met;

[0036] If satisfied, then based on the current phase / amplitude distribution of the programmable metasurface array, determine the driving signal required for each programmable metasurface unit in the programmable metasurface array;

[0037] If the conditions are not met, the phase / amplitude distribution of the programmable metasurface array is updated by back propagation, and the output light field of the programmable metasurface array is determined by forward propagation until the preset conditions are met.

[0038] The control module is used to control the thin-film transistor array to apply electrical pulses according to the driving signal, thereby outputting a dynamically shaped light field, specifically:

[0039] The driving signal is sent to the FPGA control driver to control the state of each independently addressable driving circuit in the thin-film transistor array, and to apply electrical pulses to the programmable metasurface array during the incident beam, thereby outputting a dynamically shaped light field.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The present invention discloses a programmable metasurface optical modulation method and system. This method constructs programmable metasurface units, assembling a programmable metasurface array from several such units. An integrated pixel-level addressable thin-film transistor array corresponding to the programmable metasurface array is constructed to apply variable electrical pulses to the programmable metasurface units. A phase-change material state-optical response database is built. Based on the database and the target optical field, the required driving signal for each programmable metasurface unit within the programmable metasurface array is determined. Based on the driving signal, the thin-film transistor array is controlled to apply electrical pulses, thereby outputting a dynamically shaped optical field. By utilizing phase-change materials and nanomaterials to construct programmable metasurface units, different complex optical field patterns can be switched within milliseconds, achieving "multi-purpose functionality." This enables synchronous and independent control of beam phase, amplitude, and polarization, withstands high laser power, and integrates the entire dynamic shaping structure into a chip-level device, reducing system size. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0043] Figure 1 This is a flowchart of the programmable metasurface optical modulation method provided by the present invention.

[0044] Figure 2 This is a schematic diagram of the structure of a programmable metasurface unit.

[0045] Figure 3 This is a schematic diagram of an integrated pixel-level addressable thin-film transistor array.

[0046] Figure 4 This is a structural diagram of the programmable metasurface optical modulation system provided by the present invention. Detailed Implementation

[0047] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for explaining the present invention and not for limiting the present invention. Furthermore, it should be noted that, for ease of description, only the parts related to the present invention are shown in the accompanying drawings, not all structures. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present invention.

[0048] The terms "comprising" and "having," and any variations thereof, used in this invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0049] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0050] Please see Figure 1 As shown, the present invention provides a programmable metasurface optical modulation method, which includes the following steps:

[0051] S100: Construct programmable metasurface units, and combine several programmable metasurface units into a programmable metasurface array; wherein, the programmable metasurface units contain phase change materials and nanomaterials, and the phase change materials are capable of reversible changes between crystalline and amorphous states.

[0052] Furthermore, in S100, programmable metasurface units are constructed, and several programmable metasurface units are combined into a programmable metasurface array, specifically as follows:

[0053] A phase change material layer is formed, and transparent electrodes are respectively placed on both sides of the phase change material layer; an anisotropic dielectric nanopillar is formed on one of the transparent electrodes to construct a programmable metasurface unit.

[0054] n n programmable metasurface units are arranged in an array to form a programmable metasurface array.

[0055] Please see Figure 2The programmable metasurface unit has a "sandwich" structure, with a phase change material layer in the middle, sandwiched between transparent conductive oxide electrodes on both sides. The phase change material can be, but is not limited to, Sb₂Se₃. Anisotropic dielectric nanopillars are formed on one side of the transparent conductive oxide electrode (preferably the top transparent conductive oxide electrode). By applying electrical pulses (such as voltage pulses) to the transparent conductive oxide electrodes on both sides, the ratio between the crystalline and amorphous states of the phase change material can be precisely and reversibly changed. For example, applying an electrical pulse to the phase change material can cause a reversible transition between crystalline and amorphous states. By changing the intensity of the applied electrical pulse, the content of crystalline and amorphous components in the phase change material can be changed, thereby altering the ratio of crystalline to amorphous states and creating a refractive index difference within the phase change material. It is understood that the refractive index difference within the phase change material alters the effective optical environment of the nanopillars, thus enabling dynamic resetting of the optical response of the nanopillars. Furthermore, by designing the rotation angle of the dielectric nanopillars and utilizing the geometric phase principle, the phase of the emitted light can be controlled. By designing dielectric nanopillars in specific resonant modes, the state switching of phase change materials can alter the transmittance of programmable metasurface units, achieving amplitude modulation. Furthermore, anisotropic dielectric nanopillars themselves can act as polarizers, with their polarization conversion efficiency modulated by the state of the phase change material.

[0056] S200: Construct an integrated pixel-level addressable thin-film transistor array corresponding to the programmable metasurface array, thereby applying variable electrical pulses to the programmable metasurface units.

[0057] Furthermore, in S200, an integrated pixel-level addressable thin-film transistor array corresponding to the programmable metasurface array is constructed to apply variable electrical pulses to the programmable metasurface units, specifically as follows:

[0058] Each programmable metasurface unit within the programmable metasurface array is individually configured with an independently addressable drive circuit, thereby enabling n n driving circuits form an integrated pixel-level addressable thin-film transistor array; each driving circuit applies a variable electrical pulse to its corresponding programmable metasurface unit, thereby reversibly changing the physical state of the programmable metasurface unit; wherein, the physical state may be, but is not limited to, the modulation state of the programmable metasurface unit on at least one of the phase, amplitude, and polarization of the incident beam.

[0059] n in a programmable metasurface array In a network of n programmable metasurface units, each programmable metasurface unit acts as an independent pixel unit. To drive these pixel units, a miniature, independently addressable driving circuit can be integrated beneath each unit. Thus, the programmable metasurface array functions like a miniature display backplane. Each programmable metasurface unit is assigned a corresponding independently addressable driving circuit. Through external control signals, a specific sequence of electrical pulses (such as a voltage pulse sequence) can be applied to the electrodes of each programmable metasurface unit, thereby independently and in parallel setting the state of the phase change material in each unit. In this way, the entire programmable metasurface array becomes a programmable optical field modulator. (See also...) Figure 3 The integrated pixel-level addressable thin-film transistor array includes n There are n driving circuits, each corresponding to a programmable metasurface unit, which in turn drives the programmable metasurface to work.

[0060] Specifically, the fabrication process for programmable metasurface arrays and integrated pixel-level addressable thin-film transistor arrays is as follows:

[0061] (1) Fabricate a thin film transistor backplane. On a glass substrate, the gate, channel layer and source / drain electrodes are fabricated sequentially by semiconductor processes such as sputtering, deposition, photolithography and etching to form an independently addressable pixel switch array (i.e., an integrated pixel-level addressable thin film transistor array).

[0062] (2) Fabricate an interconnect layer, coat the backplate of the thin film transistor with planarization resin and polish it, deposit and pattern indium tin oxide transparent conductive material after opening the hole to form a vertical path connecting the independently addressable pixel switch array and the programmable metasurface array.

[0063] (3) Deposit and pattern the bottom electrode. A layer of indium tin oxide transparent conductive film is deposited by magnetron sputtering. Then, the thin film is patterned into an independent electrode array using photolithography and etching processes. Each electrode is connected to a bottom thin film transistor, corresponding to a metasurface pixel.

[0064] (4) Deposit and pattern the phase change material layer. A uniform Sb2Se3 phase change material thin film is deposited on the bottom electrode using magnetron sputtering technology. Then, the micro-nano scale pattern is defined by electron beam lithography and the pattern is precisely patterned using reactive ion etching to align it with the bottom electrode.

[0065] (5) Deposit and pattern the top electrode. On the patterned phase change material layer, the top indium tin oxide transparent electrode material is deposited by magnetron sputtering. Similarly, the top electrode array corresponding to the bottom electrode array is formed by photolithography and etching to ensure that each programmable metasurface unit is held by an independently controllable electrode pair.

[0066] (6) Deposition and patterning of anisotropic dielectric nanopillar structures: A thick amorphous silicon dielectric film is deposited on the top electrode by plasma-enhanced chemical vapor deposition process, and then an anisotropic dielectric nanopillar structure is defined on the amorphous silicon dielectric film by electron beam lithography and dry etching process.

[0067] (7) Packaging and wire bonding: After the chip is fabricated, it needs to be connected to an external driving circuit. Through wire bonding technology, the electrode pads on the chip are connected to the corresponding lines on the printed circuit board (such as the FPGA circuit board), and hermetically sealed to prevent oxidation of the phase change material.

[0068] S300: Construct a state-optical response database for phase change materials.

[0069] Furthermore, in S300, a phase change material state-optical response database is constructed, specifically as follows:

[0070] Based on the ratio of crystalline to amorphous state changes of phase change materials under different electric pulses, the optical property changes of programmable metasurface units are determined; based on the changes in optical properties, a phase change material state-optical response database is constructed; wherein, optical properties include at least one of phase, amplitude, and polarization.

[0071] As discussed above, when the dielectric nanopillars of a programmable metasurface unit are designed in a specific resonant mode, the state switching of the phase change material layer alters the light transmittance of the programmable metasurface unit. It is understandable that when electrical pulses of different intensities are applied to the phase change material, the content of crystalline and amorphous components varies, resulting in different light transmittances. In other words, there is a one-to-one correspondence between the applied electrical pulse intensity and the light transmittance of the phase change material. Therefore, based on the ratio of crystalline to amorphous changes in the phase change material under different electrical pulse intensities, the transmittance change of the phase change material is determined, thereby constructing a phase change material state-optical response database. This database characterizes the correspondence between the intensity of the electrical pulse applied to the programmable metasurface unit and its light transmittance. This database can be obtained through experimental calibration or rigorous electromagnetic simulation.

[0072] S400: Based on the database and the target light field, determine the driving signal required for each programmable metasurface unit in the programmable metasurface array; based on the driving signal, control the thin-film transistor array to apply electrical pulses, thereby outputting a dynamically shaped light field.

[0073] Furthermore, in S400, based on the database and the target optical field, the required driving signal for each programmable metasurface unit within the programmable metasurface array is determined; based on the driving signal, the thin-film transistor array is controlled to apply electrical pulses, thereby outputting a dynamically shaped optical field, specifically:

[0074] Based on the database and the target light field, the phase / amplitude distribution of the programmable metasurface array is set, and the output light field of the programmable metasurface array is determined by forward propagation.

[0075] Based on the deviation between the output light field and the target light field, determine whether the preset conditions are met;

[0076] If satisfied, then based on the current phase / amplitude distribution of the programmable metasurface array, determine the driving signal required for each programmable metasurface unit in the programmable metasurface array;

[0077] If the conditions are not met, the phase / amplitude distribution of the programmable metasurface array is updated by back propagation, and the output optical field of the programmable metasurface array is determined by forward propagation until the preset conditions are met.

[0078] The drive signal is sent to the FPGA control driver to control the state of each independently addressable drive circuit in the thin-film transistor array, and to apply electrical pulses to the programmable metasurface array during the incident beam, thereby outputting a dynamically shaped light field.

[0079] In practical applications, during the incident beam onto a programmable metasurface array, electrical pulses are applied to an integrated pixel-level addressable thin-film transistor array. This alters the phase and / or amplitude of each programmable metasurface unit within the array, resulting in a corresponding phase / amplitude distribution across the entire array. Consequently, the incident beam undergoes a change in its optical field as it passes through the array, outputting a beam that matches the target optical field. A target optical field-drive mapping working mode is established for this purpose. Users do not need to understand the underlying physics; they only need to input a description of the target optical field to automatically calculate the required drive signal for each programmable metasurface unit. The target optical field can be, but is not limited to, a vortex beam with a topological charge of 3, a 5... A flat-top light spot array of 5, radially polarized light, or an arbitrarily defined complex amplitude light field. Through a reverse design algorithm, the target light field is decomposed and mapped to the ideal optical response of each programmable metasurface unit, and then converted into a specific driving electrical pulse according to the aforementioned database.

[0080] Another approach involves connecting an FPGA control driver to an integrated pixel-level addressable thin-film transistor array on a metasurface chip. When a user inputs the desired target light field via computer software, the software generates a driver file by running the aforementioned process and sends the file to the FPGA control driver. The FPGA control driver then applies electrical pulses of appropriate intensity to the addressable thin-film transistors on the metasurface chip, completing the "programming" of all addressable thin-film transistors within milliseconds. When the incident beam passes through the programmable metasurface unit corresponding to the "programmed" addressable thin-film transistors, the beam wavefront is shaped in real time, outputting a beam that matches the target light field.

[0081] Please see Figure 4 As shown, the present invention provides a programmable metasurface optical modulation system, the system comprising:

[0082] A programmable metasurface array comprises several programmable metasurface units; wherein, the programmable metasurface units contain phase change materials and nanomaterials, and the phase change materials are capable of reversible changes between crystalline and amorphous states;

[0083] An integrated pixel-level addressable thin-film transistor array is used to apply variable electrical pulses to programmable metasurface units;

[0084] Database building module, used to build a phase change material state-optical response database;

[0085] The drive signal determination module is used to determine the drive signal required for each programmable metasurface unit in the programmable metasurface array based on the database and the target light field.

[0086] The control module is used to control the thin-film transistor array to apply electrical pulses according to the driving signal, thereby outputting a dynamically shaped light field.

[0087] Furthermore, the programmable metasurface unit includes forming a phase change material layer, with transparent electrodes disposed on both sides of the phase change material layer; an anisotropic dielectric nanopillar is formed on one of the transparent electrodes.

[0088] Programmable metasurface arrays consist of n It consists of an array of n programmable metasurface units.

[0089] Furthermore, the integrated pixel-level addressable thin-film transistor array includes n n individually configured and independently addressable drive circuits; each drive circuit corresponds one-to-one with a programmable metasurface unit;

[0090] Each driving circuit applies a variable electrical pulse to its corresponding programmable metasurface unit, thereby reversibly changing the physical state of the programmable metasurface unit.

[0091] Furthermore, the database construction module is used to construct a phase change material state-optical response database, specifically:

[0092] Based on the ratio of crystalline to amorphous state changes of phase change materials under different electric pulses, the optical property changes of programmable metasurface units are determined; based on the changes in optical properties, a phase change material state-optical response database is constructed; wherein, optical properties include at least one of phase, amplitude, and polarization.

[0093] Furthermore, the drive signal determination module is used to determine the drive signal required for each programmable metasurface unit within the programmable metasurface array based on the database and the target light field, specifically:

[0094] Based on the database and the target light field, the phase / amplitude distribution of the programmable metasurface array is set, and the output light field of the programmable metasurface array is determined by forward propagation.

[0095] Based on the deviation between the output light field and the target light field, determine whether the preset conditions are met;

[0096] If satisfied, then based on the current phase / amplitude distribution of the programmable metasurface array, determine the driving signal required for each programmable metasurface unit in the programmable metasurface array;

[0097] If the conditions are not met, the phase / amplitude distribution of the programmable metasurface array is updated by back propagation, and the output optical field of the programmable metasurface array is determined by forward propagation until the preset conditions are met.

[0098] The control module is used to control the thin-film transistor array to apply electrical pulses according to the driving signal, thereby outputting a dynamically shaped light field, specifically:

[0099] The drive signal is sent to the FPGA control driver to control the state of each independently addressable drive circuit in the thin-film transistor array, and to apply electrical pulses to the programmable metasurface array during the incident beam, thereby outputting a dynamically shaped light field.

[0100] The programmable metasurface optical modulation system of the present invention operates and has the same effect as the programmable metasurface optical modulation method described above, and will not be described again here.

[0101] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of a necessary general-purpose hardware platform, or by a combination of hardware and software. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a computer product. The present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0102] 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. Other embodiments may also be used. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A programmable metasurface optical modulation method, characterized in that, The method includes the following steps: S100: Construct a programmable metasurface unit, and assemble a programmable metasurface array from several programmable metasurface units; wherein, the programmable metasurface unit contains a phase change material and a nanomaterial, and the phase change material is capable of reversible changes between crystalline and amorphous states; S200: Construct an integrated pixel-level addressable thin-film transistor array corresponding to the programmable metasurface array, thereby applying variable electrical pulses to the programmable metasurface unit; S300: Constructing a phase change material state-optical response database; S400: Based on the database and the target light field, determine the driving signal required for each programmable metasurface unit in the programmable metasurface array; based on the driving signal, control the thin-film transistor array to apply an electrical pulse, thereby outputting a dynamically shaped light field.

2. The programmable metasurface optical modulation method according to claim 1, characterized in that, In S100, programmable metasurface units are constructed, and several programmable metasurface units are combined into a programmable metasurface array, specifically as follows: A phase change material layer is formed, and transparent electrodes are respectively disposed on both sides of the phase change material layer; an anisotropic dielectric nanopillar is formed on one of the transparent electrodes to construct a programmable metasurface unit. n n programmable metasurface units are arranged in an array to form a programmable metasurface array.

3. The programmable metasurface optical modulation method according to claim 1, characterized in that, In S200, an integrated pixel-level addressable thin-film transistor array corresponding to the programmable metasurface array is constructed to apply variable electrical pulses to the programmable metasurface unit, specifically as follows: Each programmable metasurface unit within the programmable metasurface array is individually equipped with an independently addressable drive circuit, thereby enabling n n driving circuits form an integrated pixel-level addressable thin-film transistor array; each driving circuit applies a variable electrical pulse to its corresponding programmable metasurface unit, thereby reversibly changing the physical state of the programmable metasurface unit.

4. The programmable metasurface optical modulation method according to claim 1, characterized in that, In S300, a phase change material state-optical response database is constructed, specifically as follows: Based on the ratio of crystalline to amorphous state changes of the phase change material under different electric pulses, the optical property changes of the programmable metasurface unit are determined; based on the changes in optical properties, a phase change material state-optical response database is constructed; wherein, the optical properties include at least one of phase, amplitude, and polarization.

5. The programmable metasurface optical modulation method according to claim 1, characterized in that, In S400, based on the database and the target light field, the required driving signal for each programmable metasurface unit in the programmable metasurface array is determined; based on the driving signal, the thin-film transistor array is controlled to apply electrical pulses, thereby outputting a dynamically shaped light field, specifically: Based on the database and the target light field, the phase / amplitude distribution of the programmable metasurface array is set, and the output light field of the programmable metasurface array is determined by forward propagation. Based on the deviation between the output light field and the target light field, determine whether the preset conditions are met; If satisfied, then based on the current phase / amplitude distribution of the programmable metasurface array, determine the driving signal required for each programmable metasurface unit in the programmable metasurface array; If the conditions are not met, the phase / amplitude distribution of the programmable metasurface array is updated by back propagation, and the output light field of the programmable metasurface array is determined by forward propagation until the preset conditions are met. The driving signal is sent to the FPGA control driver to control the state of each independently addressable driving circuit in the thin-film transistor array, and to apply electrical pulses to the programmable metasurface array during the incident beam, thereby outputting a dynamically shaped light field.

6. A programmable metasurface optical modulation system, characterized in that, The system includes: A programmable metasurface array includes several programmable metasurface units; wherein, the programmable metasurface units contain phase change materials and nanomaterials, and the phase change materials are capable of reversibly changing between crystalline and amorphous states; An integrated pixel-level addressable thin-film transistor array is used to apply variable electrical pulses to the programmable metasurface unit; Database building module, used to build a phase change material state-optical response database; A drive signal determination module is used to determine the drive signal required for each programmable metasurface unit in the programmable metasurface array based on the database and the target light field. The control module is used to control the thin-film transistor array to apply electrical pulses according to the driving signal, thereby outputting a dynamically shaped light field.

7. The programmable metasurface optical modulation system according to claim 6, characterized in that, The programmable metasurface unit includes a phase change material layer, with transparent electrodes disposed on both sides of the phase change material layer; an anisotropic dielectric nanopillar is formed on one of the transparent electrodes. The programmable metasurface array consists of n It consists of an array of n programmable metasurface units.

8. The programmable metasurface optical modulation system according to claim 6, characterized in that, The integrated pixel-level addressable thin-film transistor array includes n n individually configured and independently addressable drive circuits; The driving circuit corresponds one-to-one with the programmable metasurface unit; Each driving circuit applies a variable electrical pulse to its corresponding programmable metasurface unit, thereby reversibly changing the physical state of the programmable metasurface unit.

9. The programmable metasurface optical modulation system according to claim 6, characterized in that, The database construction module is used to construct a phase change material state-optical response database, specifically: Based on the ratio of crystalline to amorphous state changes of the phase change material under different electric pulses, the optical property changes of the programmable metasurface unit are determined; based on the changes in optical properties, a phase change material state-optical response database is constructed; wherein, the optical properties include at least one of phase, amplitude, and polarization.

10. The programmable metasurface optical modulation system according to claim 6, characterized in that, The driving signal determination module is used to determine the driving signal required for each programmable metasurface unit in the programmable metasurface array based on the database and the target light field, specifically: Based on the database and the target light field, the phase / amplitude distribution of the programmable metasurface array is set, and the output light field of the programmable metasurface array is determined by forward propagation. Based on the deviation between the output light field and the target light field, determine whether the preset conditions are met; If satisfied, then based on the current phase / amplitude distribution of the programmable metasurface array, determine the driving signal required for each programmable metasurface unit in the programmable metasurface array; If the conditions are not met, the phase / amplitude distribution of the programmable metasurface array is updated by back propagation, and the output light field of the programmable metasurface array is determined by forward propagation until the preset conditions are met. The control module is used to control the thin-film transistor array to apply electrical pulses according to the driving signal, thereby outputting a dynamically shaped light field, specifically: The driving signal is sent to the FPGA control driver to control the state of each independently addressable driving circuit in the thin-film transistor array, and to apply electrical pulses to the programmable metasurface array during the incident beam, thereby outputting a dynamically shaped light field.

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