A method and system for optical turbulence mitigation based on MPLC and dynamic metasurface

Abstract

The application relates to a light anti-turbulence method and system based on an MPLC and a dynamic super surface. A light beam is first transmitted to a dynamic super surface, phase and amplitude modulation is realized through the dynamic super surface, then the light beam is transmitted to an MPLC structure, wavefront and field optimization modulation is realized through the MPLC structure, the modulated light signal is input to a receiving module, in the transmission process of the light beam, turbulence wavefront distortion data, vibration displacement data and light intensity fluctuation data are collected in real time, and a comprehensive interference factor is calculated, the compensation phase of the dynamic super surface and the modulation phase of the MPLC structure are calculated according to the total phase modulation instruction, and finally the total phase modulation instruction is generated, and the dynamic super surface and the MPLC structure are respectively optimized according to the total phase modulation instruction. The application realizes synchronous suppression of the coupling interference of turbulence, vibration and light intensity flicker, can be dynamically adjusted according to the change of the environment, and is suitable for different turbulence environments.

Description

Technical Field

[0001] This application relates to the field of optical communication technology, and more specifically, to an optical anti-turbulence method and system based on MPLC and dynamic metasurface. Background Technology

[0002] In free-space optical communication and satellite laser communication systems, when optical signals are transmitted through atmospheric channels, the random variations in temperature and pressure in the atmosphere lead to uneven refractive index distribution, resulting in atmospheric turbulence. Atmospheric turbulence causes wavefront distortion of the light beam, manifesting as beam drift, light intensity flicker (scintillation effect), and beam spreading. These effects lead to beam distortion at the receiving end, decreased coupling efficiency, and even communication interruption, severely impacting system reliability and transmission performance. Traditional satellite communication systems mostly use radio frequency bands for signal transmission, but their spectrum resources are limited, bandwidth is low, and they are susceptible to electromagnetic interference. Laser communication, with its high bandwidth, high directionality, and anti-interference capabilities, has become an important development direction for next-generation satellite communication. However, how to effectively suppress the impact of atmospheric turbulence on laser communication remains a pressing technical challenge in this field.

[0003] Multi-Plane Light Conversion (MPLC) technology achieves turbulence compensation by decomposing a distorted light beam into a linear superposition of multiple orthogonal modes and modulating and reconstructing the optical field on multiple phase planes. MPLC technology has advantages such as high bandwidth, passive operation, and strong robustness, making it particularly suitable for highly turbulent environments. However, traditional MPLC systems require complex mode demultiplexing and beam combining structures, resulting in large system size, high optical path loss, and difficulty in achieving dynamic, real-time wavefront modulation, thus limiting its application in miniaturized, integrated optical communication systems. Because the phase plane of traditional MPLC structures is fixed, it cannot be dynamically adjusted according to real-time changes in turbulence, limiting its adaptability in rapidly changing turbulent environments and leading to insufficient dynamic control capabilities in existing MPLC schemes. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing MPLC technology, which cannot dynamically adjust according to real-time changes in turbulence, resulting in limited dynamic control capabilities. This invention provides an optical anti-turbulence method and system based on MPLC and dynamic metasurface, which can achieve dynamic adjustment, adapt to different turbulent environments, and significantly improve response speed and accuracy.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A method for optical anti-turbulence based on MPLC and dynamic metasurfaces is provided, including:

[0007] S1. Data Acquisition: Acquire the turbulent wavefront distortion data W(x,y,t), vibration displacement data s(t), and light intensity fluctuation data of the target beam, respectively. ;

[0008] S2. Calculate the comprehensive interference factor Based on turbulent wavefront distortion data W(x,y,t), vibration displacement data s(t), and light intensity fluctuation data Calculate the comprehensive interference factor And set the initial weight coefficients for each data point;

[0009] S3. Generate the overall phase modulation command: based on the comprehensive interference factor The compensation phase of the dynamic metasurface is calculated, and the modulation phase of each phase plane in the MPLC structure is also calculated. The total phase modulation command is generated based on the compensation phase and the modulation phase.

[0010] S4. Modulation: The overall phase modulation command is converted into a corresponding voltage signal and applied to the dynamic metasurface and MPLC structure respectively. The dynamic metasurface activates the subwavelength units of the corresponding partition to achieve phase and amplitude modulation. The MPLC structure adjusts the parameters of each phase plane to optimize the wavefront and field of view.

[0011] S5. Optimize modulation: After the beam passes through the dynamic metasurface and the MPLC structure for modulation in sequence, it enters the receiving module. The receiving module analyzes the light field quality and determines whether the light field quality meets the preset requirements. If it does, the modulation ends; if it does not, it returns to step S2, adjusts the weighting coefficients, and repeats steps S1 to S5 until the light field quality meets the preset requirements.

[0012] This invention discloses an optical anti-turbulence method based on MPLC and a dynamic metasurface. The light beam is transmitted through an atmospheric channel and is subjected to coupling interference from turbulence, vibration, and light intensity scintillation. The beam is first transmitted to a dynamic metasurface, where its phase and amplitude are modulated. Then, it is transmitted to an MPLC structure, where the wavefront and field of view are optimized and modulated. The modulated optical signal is input to a receiving module. During transmission, turbulent wavefront distortion data W(x,y,t), vibration displacement data s(t), and light intensity fluctuation data are collected in real time. Then calculate the comprehensive interference factor. Comprehensive interference factor It is based on W(x,y,t), s(t), Obtained; based on The compensation phase of the dynamic metasurface and the modulation phase of the MPLC structure are then calculated to generate a total phase modulation command. Based on this command, the dynamic metasurface and MPLC structure are optimized and modulated. The optical field quality is assessed after each modulation iteration until the desired results are met. This invention achieves simultaneous suppression of coupling interference from turbulence, vibration, and optical intensity scintillation through the use of a dynamic metasurface, MPLC structure, and cyclic modulation. The method can dynamically adjust to changes in the environment, adapting to different turbulent conditions. Based on the synergistic modulation of the dynamic metasurface and MPLC, this invention significantly improves response speed and accuracy.

[0013] Furthermore, in step S2, the comprehensive interference factor is... Calculated using the following formula:

[0014]

[0015] In the formula, , , This represents the weighting coefficient.

[0016] Furthermore, in step S3, the compensation phase of the dynamic metasurface... Calculated using the following formula:

[0017]

[0018] In the formula, This indicates the system calibration phase, used to compensate for static errors; This represents the weighted turbulence wavefront distortion data;

[0019] Total phase modulation command Calculated using the following formula:

[0020]

[0021] In the formula, The phase of the phase plane in the MPLC structure is represented by i, where i represents the index of the phase plane and n represents the number of phase planes in the MPLC structure.

[0022] Furthermore, the dynamic metasurface is divided into multiple independent subwavelength unit arrays, each of which can be activated or deactivated individually.

[0023] Further, in step S4, according to The relationship between the power consumption and a preset threshold is used to dynamically adjust the number of activated subwavelength units, thereby achieving dynamic adjustment of power consumption.

[0024] Furthermore, when When the value is greater than the first threshold, all subwavelength units of the dynamic metasurface are activated; when When the threshold is less than or equal to the first threshold and greater than the second threshold, the subwavelength unit of half of the dynamic metasurface is activated; when When the value is less than the second threshold, the subwavelength units of 1 / 4 of the dynamic metasurface are activated.

[0025] Furthermore, power consumption is dynamically adjusted using the following formula:

[0026]

[0027] In the formula, Indicates total power consumption; represents full power; m represents the number of activated subwavelength units; M represents the total number of subwavelength units.

[0028] Furthermore, the dynamic metasurface includes a subwavelength structure array and a composite functional material layer. By adjusting the height and duty cycle of the subwavelength units, phase adjustment at different wavelengths can be achieved.

[0029] This invention also provides an optical anti-turbulence system based on MPLC and dynamic metasurface, comprising:

[0030] Light source module: used to generate multi-band beams and transmit them to the dynamic metasurface module;

[0031] Dynamic metasurface module: used to achieve joint dynamic modulation of the amplitude and phase of the beam. The beam modulated by the homomorphic metasurface module is transmitted to the MPLC module.

[0032] MPLC module: used to adjust the wavefront and field of view of the beam; the beam modulated by the MPLC module is transmitted to the receiving module;

[0033] Control module: Includes a multi-interference sensing unit, used to collect turbulent wavefront distortion data W(x,y,t), vibration displacement data s(t), and light intensity fluctuation data of the light beam, respectively. Coordinated scheduling unit: Used for real-time processing of data collected by multiple interference sensing units, including calculating the comprehensive interference factor. ,according to The system calculates the compensation phase of the dynamic metasurface, the modulation phase of each phase plane in the MPLC structure, and generates a total phase modulation command based on the compensation phase and modulation phase. The driving unit converts the total modulation command into a corresponding voltage signal, which is applied to the dynamic metasurface module and the MPLC module respectively. The dynamic metasurface activates the subwavelength units of the corresponding partition to achieve phase and amplitude modulation. The MPLC structure adjusts the parameters of each phase plane to optimize the wavefront and field of view.

[0034] The receiving module receives the modulated optical signal, analyzes the optical field quality, and determines whether the optical field quality meets the preset requirements. If it does, modulation ends; otherwise, the integrated interference factor is adjusted. W(x,y,t), s(t), The corresponding weighting coefficients are applied until the light field quality meets the preset requirements.

[0035] Furthermore, the comprehensive interference factor Calculated using the following formula:

[0036]

[0037] In the formula, , , This represents the weighting coefficient.

[0038] Furthermore, the compensated phase of dynamic metasurfaces Calculated using the following formula:

[0039]

[0040] In the formula, This indicates the system calibration phase, used to compensate for static errors; This represents the weighted turbulence wavefront distortion data;

[0041] Total phase modulation command Calculated using the following formula:

[0042]

[0043] In the formula, The phase of the phase plane in the MPLC structure is represented by i, where i represents the index of the phase plane and n represents the number of phase planes in the MPLC structure.

[0044] Furthermore, the dynamic metasurface module is divided into multiple independent subwavelength unit arrays, each of which can be individually activated or deactivated; according to The relationship between the power consumption and a preset threshold is used to dynamically adjust the number of activated subwavelength units, thereby achieving dynamic adjustment of power consumption.

[0045] Compared with the prior art, the beneficial effects of the present invention are:

[0046] This invention discloses an optical anti-turbulence method and system based on MPLC and dynamic metasurface. Through dynamic metasurface, MPLC structure, and cyclic modulation process, it achieves synchronous suppression of coupling interference from turbulence, vibration, and light intensity scintillation. It can dynamically adjust according to changes in the environment, thereby adapting to different turbulent environments. Based on the synergistic modulation of dynamic metasurface and MPLC, this invention significantly improves response speed and accuracy. Attached Figure Description

[0047] Figure 1 This is a flowchart illustrating an optical anti-turbulence method based on MPLC and dynamic metasurfaces in one embodiment.

[0048] Figure 2 This is a schematic diagram illustrating the principle of cooperative modulation feedback in one embodiment;

[0049] Figure 3 This is a schematic diagram of the structural relationship of an optical anti-turbulence system based on MPLC and dynamic metasurface in one embodiment;

[0050] Figure 4 This is a schematic diagram of the structure of an optical anti-turbulence system based on MPLC and dynamic metasurface in another embodiment.

[0051] In the attached diagram: 1. Base; 2. Column; 3. Fiber array combiner; 4. Fiber array output head; 5. Gold-plated reflector; 6. Multi-plane phase plane; 7. Fiber collimator; 8. Dynamic metasurface module. Detailed Implementation

[0052] The present invention will be further described below with reference to specific embodiments. The accompanying drawings are for illustrative purposes only, representing schematic diagrams rather than actual physical objects, and should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0053] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0054] Example 1

[0055] This embodiment is a first embodiment of an optical anti-turbulence method based on MPLC and dynamic metasurface. The method of the present invention adopts the structure shown in the figure, including a light source module, a dynamic metasurface module, an MPLC module, a receiving module, a multi-interference sensing unit, a cooperative scheduling unit, and a driving unit. The light beam emitted by the light source module is transmitted through an atmospheric channel and is subject to coupling interference from turbulence, vibration, and light intensity flicker. The multi-interference sensing unit collects turbulence wavefront distortion data W(x,y,t), vibration displacement data s(t), and light intensity fluctuation data in real time. The beam is transmitted to the collaborative scheduling unit, which calculates various data and converts them into electrical signals. These signals are then used by the drive unit to control the dynamic metasurface module to adjust the phase and amplitude of the beam, while simultaneously controlling the phase plane parameters of the MPLC structure. After passing through the dynamic metasurface module, the beam is transmitted to the MPLC module, where it undergoes further processing via multiple phase planes to optimize the wavefront and field of view. Finally, the beam, after anti-turbulence processing, is received by the receiving module, which feeds back the optical field quality data to the collaborative scheduling module, achieving closed-loop adjustment. Specifically, as shown in the figure, the process includes the following steps:

[0056] Step S1. Data Acquisition: The beam is transmitted through an atmospheric channel and is subject to coupling interference from turbulence, vibration, and light intensity scintillation; the turbulence wavefront distortion data W(x,y,t), vibration displacement data s(t), and light intensity fluctuation data of the target beam are acquired respectively. .

[0057] Step S2. Calculate the comprehensive interference factor Based on turbulent wavefront distortion data W(x,y,t), vibration displacement data s(t), and light intensity fluctuation data Calculate the comprehensive interference factor And set the initial weight coefficients for each data point.

[0058] Comprehensive interference factor Calculated using the following formula:

[0059]

[0060] In the formula, , , This represents the weighting coefficients. The weighting coefficients are initially set according to the application scenario. For example, when turbulence is the primary disturbance, α=0.6, β=0.3, and γ=0.1.

[0061] Step S3. Generate the overall phase modulation command: based on the integrated interference factor The compensation phase of the dynamic metasurface is calculated, and the modulation phase of each phase plane in the MPLC structure is also calculated. The total phase modulation command is generated based on the compensation phase and the modulation phase.

[0062] Among them, the compensated phase of the dynamic metasurface Calculated using the following formula:

[0063]

[0064] In the formula, This indicates the system calibration phase, used to compensate for static errors;

[0065] Total phase modulation command Calculated using the following formula:

[0066]

[0067] In the formula, The phase of the phase plane in the MPLC structure is represented by i, where i represents the index of the phase plane and n represents the number of phase planes in the MPLC structure.

[0068] Step S4. Modulation: The overall phase modulation command is converted into a corresponding voltage signal and applied to the dynamic metasurface and the MPLC structure respectively. The dynamic metasurface activates the subwavelength units of the corresponding partition to achieve phase and amplitude modulation. The MPLC structure adjusts the parameters of each phase plane to optimize the wavefront and field of view.

[0069] Step S5. Optimize modulation: After the beam passes through the dynamic metasurface and the MPLC structure for modulation in sequence, it enters the receiving module. The receiving module analyzes the light field quality and determines whether the light field quality meets the preset requirements. If it does, the modulation ends; if it does not, it returns to step S2, adjusts the weighting coefficients, and repeats steps S1 to S5 until the light field quality meets the preset requirements.

[0070] In step S5, the analysis and judgment of the optical field quality can be based on the bit error rate (BER). By calculating the BER, it can be determined whether the BER is greater than 10. -6 If the value is greater than the threshold, it indicates that the requirement is not met. Return to step S2 to readjust the weighting coefficients and repeat steps S1 to S5 until the light field quality meets the preset requirements.

[0071] In this embodiment, the dynamic metasurface is divided into multiple independent subwavelength unit arrays, each of which can be activated or deactivated individually. In step S4, according to The relationship with a preset threshold is used to dynamically adjust the number of activated subwavelength units, thereby achieving dynamic power consumption adjustment. Specifically, when... When the value is greater than the first threshold, all subwavelength units of the dynamic metasurface are activated; when When the threshold is less than or equal to the first threshold and greater than the second threshold, the subwavelength unit of half of the dynamic metasurface is activated; when When the value is less than the second threshold, the subwavelength units of 1 / 4 of the dynamic metasurface are activated.

[0072] In this embodiment, power consumption is dynamically adjusted using the following formula:

[0073]

[0074] In the formula, Indicates total power consumption; F(t) represents full power; m represents the number of activated subwavelength units; M represents the total number of subwavelength units. In weak interference scenarios (F(t) < third threshold), the dynamic metasurface is controlled by the above formula to reduce the number of activated subwavelength units, thereby reducing system power consumption and maintaining stable communication performance.

[0075] Furthermore, the dynamic metasurface comprises a subwavelength structure array and a composite functional material layer. By adjusting the height and duty cycle of the subwavelength units, phase modulation at different wavelengths can be achieved. Using silicon nitride-silicon dioxide composite subwavelength units, by adjusting the unit height h (300-800 nm) and duty cycle d (0.3-0.7), the dynamic metasurface can achieve 0-2π phase modulation in the 400-1600 nm wavelength range, satisfying the requirements of... Different wavelength bands correspond to preset h and d parameters (e.g., 450nm visible light corresponds to h=400nm, d=0.5; 1550nm infrared light corresponds to h=600nm, d=0.6), and wavelength band adaptation is achieved by switching parameters through the driving unit. The wide-band compatible dynamic metasurface design in this embodiment breaks through the limitation of traditional dynamic metasurfaces adapting to a single wavelength band. It can be compatible with multiple scenarios such as visible light lidar imaging and near-infrared optical communication, without the need to replace optical components, thus improving the system's versatility.

[0076] In this embodiment, step S3 is based on the comprehensive interference factor. The compensation phase of a dynamic metasurface is calculated indirectly through "weighting coefficient adaptation"—the core function of F(t) is to dynamically adjust the weighting coefficients. This determines the contribution percentage of each interference term to the compensation phase. It is dynamically adjusted based on the calculation results of F(t). For example, when F(t) shows "extremely high proportion of turbulent interference", it will increase. , reduce This allows the compensation to focus more on turbulence. The compensation phase formula for dynamic metasurfaces. Although there is no direct correlation with F(t), it is within It is the turbulent wavefront distortion data adjusted by F(t).

[0077] In this embodiment, step S3, calculating the modulation phase of each phase plane in the MPLC structure, includes the following steps:

[0078] 1. Pre-calibration stage (completed offline):

[0079] Determine the functional division of MPLC phase surfaces: Assign compensation tasks to each phase surface according to aberration type (taking 4 phase surfaces as an example). Phase surface 1: compensates for tilt and defocus aberrations; Phase surface 2: compensates for astigmatism and coma aberrations; Phase surfaces 3-4: compensate for higher-order aberrations (through Zernike polynomial decomposition).

[0080] Experiments / simulations were used to obtain the aberration-phase correspondence: For different interference scenarios (such as "weak turbulence + small vibration" and "strong turbulence + large scintillation"), the corresponding aberration distributions were collected; for each phase surface, the "reverse compensation phase" (i.e., calibration aberration phase distribution) was calculated. ); Store “Interference Scene → Calibrate Phase for Each Phase Surface” as a pre-calibrated phase table.

[0081] 2. Real-time calculation stage (online execution):

[0082] Receive F(t) and interference data: The collaborative scheduling module obtains the comprehensive interference factor. And the original data of each interference item ( ).

[0083] Pre-calibrate the phase based on F(t): The magnitude (corresponding to the interference intensity) is used to select the calibration for the corresponding scenario from the pre-calibration phase table. If F(t) is within the scene range, the phase is fine-tuned and calibrated using "linear interpolation".

[0084] Calculate the real-time modulation phase of each phase plane: Substitute the corresponding formulas for phase planes with different functions:

[0085] Phase plane 1 (tilted + out of focus):

[0086] calibration, ; For the coefficients matched in the pre-calibration table;

[0087] Phase plane 2 (astigmatism + coma):

[0088] calibration, , For the coefficients matched in the pre-calibration table;

[0089] Phase planes 3-4 (higher-order aberrations):

[0090] calibration, , For Zernike polynomials, These are the coefficients matched in the pre-calibration table.

[0091] This embodiment provides an optical anti-turbulence method based on MPLC and dynamic metasurfaces. It employs a collaborative control mechanism between the dynamic metasurface and MPLC structure, overcoming the design limitations of traditional "separation of dynamic modulation and static shaping," and establishing a collaborative working logic between the dynamic metasurface and MPLC. The dynamic metasurface, with its microsecond-level response speed, is responsible for compensating for high-frequency dynamic interference (such as millisecond-level wavefront distortion caused by turbulence and high-frequency displacement caused by vibration); the MPLC, through multi-phase surface cascade modulation, is responsible for optimizing low-order aberrations (such as defocus and astigmatism) and expanding the field of view. The two achieve functional complementarity through total phase superposition, corely satisfying… The method in this embodiment can still maintain a compensation accuracy of λ / 20 under a large field of view of 120°×30°, which solves the contradiction between "large field of view and high accuracy" in traditional technology, and at the same time improves the system's adaptability to rapidly changing interference.

[0092] The optical anti-turbulence method based on MPLC and dynamic metasurfaces provided in this embodiment employs multi-interference joint sensing compensation. It addresses the coupled interference of turbulence, vibration, and light intensity flicker by achieving precise compensation through multi-sensor data fusion. A weighted fusion model is used to calculate the comprehensive interference factor. The weighting coefficients α, β, and γ can be dynamically adjusted according to the real-time interference intensity (e.g., β increases from 0.3 to 0.5 when vibration intensifies) to ensure that the system prioritizes compensation for the main interference sources. The specific compensation process includes: collecting three types of data → calculating F(t) using the fusion model → generating targeted modulation commands → performing compensation using the dynamic metasurface and MPLC → feedback adjustment from the receiving module, forming a closed-loop control that effectively reduces the bit error rate under coupled interference.

[0093] The optical anti-turbulence method based on MPLC and dynamic metasurfaces provided in this embodiment employs a low-power partitioned modulation strategy. This involves dividing the dynamic metasurface into multiple independent subwavelength units and determining the number of activated subwavelength units, m, based on the magnitude of the comprehensive interference factor F(t). It enables dynamic power consumption adjustment, reducing power consumption by 40% in weak interference scenarios, meeting the long battery life requirements of portable devices such as drones and mobile terminals, while avoiding system overheating caused by ineffective power consumption.

[0094] In summary, the optical anti-turbulence method based on MPLC and dynamic metasurfaces provided in this embodiment has the following beneficial effects:

[0095] 1. Outstanding Multi-Interference Collaborative Compensation Capability: This embodiment, through multi-interference sensing units and a fusion model, can simultaneously suppress coupled interference from turbulence, vibration, and light intensity flicker. In complex scenarios (such as drone flight and vehicle environments), the bit error rate is reduced from 10% in traditional technologies. -3 Reduced to 10-7 The system availability rate has increased from less than 80% to 99.5%, solving the core pain point that existing technologies cannot cope with multiple interference couplings.

[0096] 2. Strong wide band adaptability: The dynamic metasurface adopts a silicon nitride-silicon dioxide composite structure, covering the 400-1600nm band, which is compatible with multiple scenarios such as visible light lidar and near-infrared optical communication. There is no need to design independent systems for different bands. The application range is more than 3 times larger than the traditional single-band solution, which significantly improves the system versatility and industrialization value.

[0097] 3. Balancing large field of view and high precision: Through the dynamic metasurface-MPLC collaborative control mechanism, it can still maintain a compensation accuracy of λ / 20 under a large field of view of 120°×30°, which is twice the field of view of traditional MPLC systems (field of view ≤60°) and 50% higher than adaptive optics systems (accuracy ≥λ / 10 in strong turbulence scenes), meeting the needs of long-distance optical communication and large-area lidar detection.

[0098] 4. Significant advantages in low power consumption and miniaturization: The dynamic metasurface partitioning modulation strategy reduces system power consumption by 40%, extending flight time from 2 hours to 3.5 hours in drone application scenarios; at the same time, by integrating the dynamic metasurface with MPLC, the system size is reduced by 70% (≤5cm×3cm×1cm) compared to the traditional AO+MPLC combination solution, making it suitable for portable scenarios such as mobile terminals and drones, and solving the contradiction between "high precision and low power consumption and miniaturization" in existing technologies.

[0099] 5. High real-time performance and stability: The dynamic metasurface response speed reaches the microsecond level, which is 1000 times faster than traditional deformable mirrors (millisecond level), and can track high-frequency interference in real time; at the same time, the closed-loop feedback control mechanism adjusts parameters in real time through the receiving module, even under drastic changes in turbulence intensity (Cn²=10). -12 10 -14 m -2 / 3 Even when the interference is severe, it can still maintain stable communication performance, and its anti-interference robustness is significantly better than existing technologies.

[0100] Example 2

[0101] This embodiment is a first embodiment of an optical anti-turbulence system based on MPLC and dynamic metasurface, as shown in the figure, including:

[0102] Light source module: generates stable, monochromatic multi-band beams (covering 400-1600nm), for example, by using a multi-band laser diode (LD) array; through the multi-band laser diode array, a stable 400-1600nm band beam is generated under the control of the driving current to meet the band requirements of different application scenarios.

[0103] Dynamic metasurface module: As a spatial light phase modulator, it adopts a silicon nitride-silicon dioxide composite subwavelength unit structure (unit size 500-800nm) to achieve joint dynamic modulation of beam amplitude and phase, and supports wide-band adaptation of 400-1600nm; based on the subwavelength structure array and composite functional material layer, phase modulation at different wavelengths is achieved by adjusting the unit height h and duty cycle d, and the core meets the requirements of... (k=2π / λ is the wave number, (This refers to the refractive index difference of the composite material at wavelength λ). At the same time, a partitioned design is adopted, which can dynamically activate the corresponding subwavelength unit according to the interference intensity, thereby reducing power consumption.

[0104] The MPLC module includes 3-6 configurable phase planes (the number depends on the application scenario) for further adjusting the wavefront of the beam, optimizing low-order aberrations, and expanding the field of view. It progressively transforms the input beam into the target light field distribution. Each phase plane undertakes a different modulation task (low-order aberration correction, high-order aberration optimization, etc.), and calculates the modulation function of each phase plane using an iterative optimization algorithm (such as the GS algorithm). (i is the phase plane number), to achieve high-precision beam shaping under a large field of view.

[0105] The control module includes:

[0106] The multi-interference sensing unit integrates a Hartmann-Shack sensor (wavefront distortion detection), an RFID frequency shift sensor (vibration displacement detection), and a light intensity detector (light intensity fluctuation detection) to collect turbulent wavefront distortion data W(x,y,t), vibration displacement data s(t), and light intensity fluctuation data of the light beam, respectively. ;

[0107] The collaborative scheduling unit is used to process data collected by multiple interference sensing units in real time, calculate modulation parameters, and generate modulation commands. The collaborative scheduling unit also calculates the comprehensive interference factor through a multi-interference fusion model. α, β, and γ are the weights of wavefront distortion, vibration, and light intensity fluctuation, respectively; W(x,y,t) is the wavefront distortion; and s(t) is the vibration displacement. This represents the light intensity fluctuation. The initial light intensity is used, and a total phase modulation command is generated based on the cooperative modulation logic. , For dynamic metasurface compensation phase, n is the number of MPLC phase surfaces;

[0108] The driving unit is used to convert the overall modulation command into a corresponding voltage signal, which is applied to the dynamic metasurface module and the MPLC module respectively. The dynamic metasurface activates the subwavelength units of the corresponding partition to achieve phase and amplitude modulation; the MPLC structure adjusts the parameters of each phase plane to optimize the wavefront and field of view.

[0109] The receiving module, including a photodetector and a signal processing unit, receives the light beam after anti-turbulence processing and provides optical field quality feedback. The photodetector converts the optical signal into an electrical signal, and the signal processing unit demodulates and analyzes the electrical signal, extracting optical field quality parameters (such as beam uniformity and intensity stability), which are then fed back to the collaborative scheduling module to dynamically adjust the weighting coefficients and modulation parameters.

[0110] In this embodiment, the dynamic metasurface module is divided into multiple independent subwavelength unit arrays, each of which can be activated or deactivated individually; according to The relationship with a preset threshold is used to dynamically adjust the number of activated subwavelength units, thereby achieving dynamic power consumption adjustment. When When the value is greater than the first threshold, all subwavelength units of the dynamic metasurface are activated; when When the threshold is less than or equal to the first threshold and greater than the second threshold, the subwavelength unit of half of the dynamic metasurface is activated; when When the value is less than the second threshold, the subwavelength units of 1 / 4 of the dynamic metasurface are activated.

[0111] In this embodiment, power consumption is dynamically adjusted using the following formula:

[0112]

[0113] In the formula, Indicates total power consumption; F(t) represents full power; m represents the number of activated subwavelength units; M represents the total number of subwavelength units. In weak interference scenarios (F(t) < third threshold), the dynamic metasurface is controlled by the above formula to reduce the number of activated subwavelength units, thereby reducing system power consumption and maintaining stable communication performance.

[0114] This embodiment is the system embodiment corresponding to the method described in embodiment one. Its core content is similar to that of embodiment one, and the beneficial effects obtained are also similar to those of embodiment one, so it will not be repeated here.

[0115] Example 3

[0116] This embodiment is a second embodiment of an optical anti-turbulence system based on MPLC and dynamic metasurface. This embodiment is similar to the first embodiment, except that it provides a specific system implementation method, as shown in the figure, including:

[0117] Base 1: Provides system support and fixation, made of aluminum alloy, weighs ≤500g, and has an anti-static treatment on the surface.

[0118] Support column 2: Connects the overall base to each optical module. The height is adjustable (range 5-10cm). It is made of carbon fiber to ensure lightweight and stability.

[0119] Fiber optic array combiner 3: Combines the beams output from a multi-band laser diode array into a single beam with a combining efficiency of ≥95% and supports the 400-1600nm band.

[0120] Fiber optic array output head 4: Outputs the combined beam with an adjustable output spot diameter (0.5-2mm). It uses a sapphire window, which is wear-resistant and has a light transmittance of ≥98%.

[0121] Gold-plated reflector 5: Changes the direction of beam transmission, with a reflectivity ≥99.5% and an adjustable angle (±5°), used to optimize the optical path layout;

[0122] Multi-plane phase plane 6: Contains 4 phase planes (can be expanded to 3-6 as needed), made of silicon-based material, each phase plane is 10mm×10mm in size, and the phase modulation range is 0-2π; the gold-plated reflector and the multi-plane phase planes constitute an important part of the MPLC module; in practical applications, the specific structure of the MPLC can be designed according to needs.

[0123] Fiber collimator 7: Receives the distorted beam after atmospheric transmission, with a collimation accuracy of ≤0.1mrad, compatible with multimode fiber, and a numerical aperture of 0.22.

[0124] Dynamic Metasurface Module 8: It adopts a silicon nitride-silicon dioxide composite structure, an 8×8 subwavelength unit array, each unit size is 800nm×800nm, the response speed is ≤1μs, and it supports modulation in the 400-1600nm band.

[0125] Control module: includes a multi-interference sensing unit, a coordinated scheduling unit, and a drive unit.

[0126] Receiver module: Includes photodetector and signal processing unit, and also has light field quality feedback function.

[0127] The specific workflow includes:

[0128] (1) The multi-band laser diode array (including three bands: 450nm, 850nm and 1550nm) of the light source module is started. After the beam is combined by the fiber array combiner, it is output by the fiber array output head and enters the atmospheric channel for transmission.

[0129] (2) The light beam is subjected to turbulence in the atmosphere (Cn) 2 =10 -14 m -2 / 3Interference from building vibration (frequency 5-20Hz) and light intensity flicker (flicker index 0.3) generates wavefront distortion and light intensity fluctuations, which are then received by the fiber optic collimator and transmitted to the dynamic metasurface module.

[0130] (3) Synchronous operation of multiple interference sensing units: Hartmann-Shack sensor collects turbulent wavefront distortion data W(x,y,t), RFID frequency shift sensor collects vibration displacement data s(t), and light intensity detector collects light intensity fluctuation data. The data is then transmitted to the collaborative scheduling unit.

[0131] (4) The collaborative scheduling unit calculates the comprehensive interference factor based on the multi-interference fusion model. (Initial weight settings, turbulence is the main disturbance), and calculate the dynamic metasurface compensation phase. , Pre-calibrate the phase of the system to compensate for static optical path errors; This represents the turbulent wavefront distortion data after weight adjustment.

[0132] (5) The coordinated scheduling unit simultaneously calculates the modulation phase of the four phase planes of the MPLC. (Correct tilt, defocus) (Compensation for astigmatism and coma) (Optimization of higher-order aberrations 1) (Optimize higher-order aberrations 2), generate total modulation command .

[0133] (6) The driving unit converts the total modulation command into a voltage signal (0-5V) and applies it to the dynamic metasurface module and the MPLC module: the dynamic metasurface activates all 64 units (currently F(t) is in the high threshold range), adjusting the beam phase and amplitude; the four phase surfaces of the MPLC module adjust according to... Adjust the parameters to expand the field of view to 120°×30°.

[0134] (7) After the modulated beam is adjusted in direction by the gold-plated reflector, it enters the photodetector (InGaAs detector, response band 400-1700nm) of the receiving module, is converted into an electrical signal and transmitted to the signal processing unit.

[0135] (8) The signal processing unit analyzes the electrical signal and obtains a bit error rate of 8×10. -7 (Meeting the requirements), while simultaneously feeding back the light field quality data to the collaborative scheduling unit; if the bit error rate > 10 -6 The collaborative scheduling module then adjusts the weighting coefficients (e.g., increasing β to 0.4) and recalculates the modulation parameters until the performance requirements are met.

[0136] In the specific implementation of the above embodiments, the technical features can be combined in any non-contradictory way. For the sake of brevity, not all possible combinations of the above technical features are described. However, as long as the combination of these technical features is not contradictory, it should be considered to be within the scope of this specification.

[0137] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for optical anti-turbulence based on MPLC and dynamic metasurfaces, characterized in that, include: S1. Data Acquisition: Acquire the turbulent wavefront distortion data W(x,y,t), vibration displacement data s(t), and light intensity fluctuation data of the target beam, respectively. ; S2. Calculate the comprehensive interference factor Based on turbulent wavefront distortion data W(x,y,t), vibration displacement data s(t), and light intensity fluctuation data Calculate the comprehensive interference factor And set the initial weight coefficients for each data point; among them, the comprehensive interference factor Calculated using the following formula: In the formula, , , Indicates the weighting coefficient; S3. Generate the overall phase modulation command: based on the comprehensive interference factor The compensation phase of the dynamic metasurface is calculated, and the modulation phase of each phase plane in the MPLC structure is also calculated. Based on the compensation phase and modulation phase, a total phase modulation command is generated. The compensation phase of the dynamic metasurface... Calculated using the following formula: In the formula, This indicates the system calibration phase, used to compensate for static errors; This represents the weighted turbulence wavefront distortion data; Total phase modulation command Calculated using the following formula: In the formula, This represents the phase of the phase plane in the MPLC structure, where i represents the index of the phase plane and n represents the number of phase planes in the MPLC structure. S4. Modulation: The overall phase modulation command is converted into a corresponding voltage signal and applied to the dynamic metasurface and MPLC structure respectively. The dynamic metasurface activates the subwavelength units of the corresponding partition to achieve phase and amplitude modulation. The MPLC structure adjusts the parameters of each phase plane to optimize the wavefront and field of view. S5. Optimize modulation: After the beam passes through the dynamic metasurface and the MPLC structure for modulation in sequence, it enters the receiving module. The receiving module analyzes the light field quality and determines whether the light field quality meets the preset requirements. If it does, the modulation ends; if it does not, it returns to step S2, adjusts the weighting coefficients, and repeats steps S1 to S5 until the light field quality meets the preset requirements.

2. The optical anti-turbulence method based on MPLC and dynamic metasurfaces according to claim 1, characterized in that, The dynamic metasurface is divided into multiple independent subwavelength unit arrays, each of which can be activated or deactivated individually.

3. The optical anti-turbulence method based on MPLC and dynamic metasurfaces according to claim 2, characterized in that, In step S4, according to The relationship between the power consumption and a preset threshold is used to dynamically adjust the number of activated subwavelength units, thereby achieving dynamic adjustment of power consumption.

4. The optical anti-turbulence method based on MPLC and dynamic metasurfaces according to claim 2, characterized in that, The dynamic metasurface comprises a subwavelength structure array and a composite functional material layer. By adjusting the height and duty cycle of the subwavelength units, phase adjustment at different wavelengths can be achieved.

5. A light-induced turbulence suppression system based on MPLC and dynamic metasurfaces, characterized in that, include: Light source module: used to generate multi-band beams and transmit them to the dynamic metasurface module; Dynamic metasurface module: used to achieve joint dynamic modulation of the amplitude and phase of the beam. The beam modulated by the homomorphic metasurface module is transmitted to the MPLC module. MPLC module: used to adjust the wavefront and field of view of the beam; the beam modulated by the MPLC module is transmitted to the receiving module; Control module: Includes a multi-interference sensing unit, used to collect turbulent wavefront distortion data W(x,y,t), vibration displacement data s(t), and light intensity fluctuation data of the light beam, respectively. ; Cooperative scheduling unit: Used for real-time processing of data collected by multiple interference sensing units, including calculating the comprehensive interference factor. ,according to The system calculates the compensation phase of the dynamic metasurface, the modulation phase of each phase plane in the MPLC structure, and generates a total phase modulation command based on the compensation phase and modulation phase. The driving unit converts the total modulation command into a corresponding voltage signal, which is applied to the dynamic metasurface module and the MPLC module respectively. The dynamic metasurface activates the subwavelength units of the corresponding partition to achieve phase and amplitude modulation. The MPLC structure adjusts the parameters of each phase plane to optimize the wavefront and field of view. The receiving module receives the modulated optical signal, analyzes the optical field quality, and determines whether the optical field quality meets the preset requirements. If it does, modulation ends; otherwise, the integrated interference factor is adjusted. W(x,y,t), s(t), The corresponding weighting coefficients are applied until the light field quality meets the preset requirements; Among them, the comprehensive interference factor Calculated using the following formula: In the formula, , , Indicates the weighting coefficient; Compensation phase of dynamic metasurfaces Calculated using the following formula: In the formula, This indicates the system calibration phase, used to compensate for static errors; This represents the weighted turbulence wavefront distortion data; Total phase modulation command Calculated using the following formula: In the formula, The phase of the phase plane in the MPLC structure is represented by i, where i represents the index of the phase plane and n represents the number of phase planes in the MPLC structure.

6. The optical anti-turbulence system based on MPLC and dynamic metasurface according to claim 5, characterized in that, The dynamic metasurface module is divided into multiple independent subwavelength unit arrays, each of which can be individually activated or deactivated; according to... The relationship between the power consumption and a preset threshold is used to dynamically adjust the number of activated subwavelength units, thereby achieving dynamic adjustment of power consumption.

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