Vortex light cross-sea surface transmission simulation method and system based on electric field Monte Carlo method

Abstract

The invention relates to a vortex light cross-sea surface transmission simulation method and system based on an electric field Monte Carlo method. The method comprises the following steps: S10, loading photons and carrying out initialization setting; s20, calculating the position change of the photons in the random walk process in the channel; s30, judging whether the photons reach the detection surface or are scattered or not according to the position change of the photons, if so, returning to the step S10, and otherwise, entering the step S40; s40, the absorptivity of photons is calculated, and local orthogonal coordinates are converted; s50, selecting and determining whether the photons survive or not through a survival wheel disc, if so, returning to the step S20, and if not, entering the step S60; s60, judging whether all photons are calculated or not, if so, entering the step S70, and if not, returning to the step S10; and S70, calculating an accumulated electric field under the action of the sea surface beam influence factors to obtain electric field intensity, and recording and storing the electric field intensity. According to the invention, the cross-sea-surface transmission process of vortex light can be simulated more accurately, and accumulated electric field information is obtained.

Description

Technical Field

[0001] The present invention relates to the field of optical communication technology, and in particular to a method and system for simulating vortex light transmission across sea surface based on an electric field Monte Carlo method. Background Art

[0002] The transmission characteristics of light beams in the marine environment are of great significance to applications such as marine optical communications and marine lidar. The Monte Carlo method is a numerical calculation method based on random sampling, which is widely used to simulate various complex physical processes, including the propagation and scattering of light. In the field of optics, especially the propagation of light in complex media (such as air, seawater, etc.), the Monte Carlo method simulates the absorption, scattering and other behaviors of photons in the medium by tracking a large number of photon trajectories. In this way, the Monte Carlo method can accurately describe the transmission process of light statistically, and is particularly suitable for dealing with problems such as multiple scattering and light transmission in random media.

[0003] However, traditional Monte Carlo methods usually only care about the macroscopic state of photons, such as position, direction, energy, etc. For example, in the invention with publication number CN 114884599A, "Construction method of blue-green vortex light sea cross-medium collimated incidence single-pass transmission model", the coherence and interference effects of photons after multiple scattering are often ignored during the simulation process, resulting in inaccurate simulation of the vortex light transmission process. Summary of the invention

[0004] The purpose of the present invention is to provide a method and system for simulating the transmission of vortex light across the sea surface based on the electric field Monte Carlo method, so as to improve the problem of insufficient accuracy in the simulation of the transmission of vortex light across the sea surface in the prior art.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] In a first aspect, the present invention provides a method for simulating vortex light transmission across the sea surface based on an electric field Monte Carlo method, comprising the following steps:

[0007] S10, loading photons and performing initialization settings, including setting the initial coordinates, initial direction cosines, initial parallel components of the complex electric field and initial vertical components of the complex electric field. The initial parallel components of the complex electric field and initial vertical components of the complex electric field are set to and E 2 = 0, where i represents the imaginary unit, l represents the topological charge of the vortex beam, is the azimuth;

[0008] S20, calculate the position change of the photon during random walk in the channel;

[0009] S30, judging whether the photon has reached the detection surface or has been scattered according to the change in the position of the photon, if yes, returning to step S10 to simulate the scattering process of the next photon; if no, proceeding to step S40;

[0010] S40, calculating the absorption rate of photons and local orthogonal coordinate transformation, and then proceeding to step S50;

[0011] S50, determining whether the photon survives by selecting the survival roulette wheel, if yes, returning to step S20, continuing to simulate the subsequent behavior of the photon, if no, the photon no longer survives, entering step S60;

[0012] S60, determining whether all photons have been calculated, if yes, proceeding to step S70, if no, returning to step S10 to simulate the scattering process of the next photon;

[0013] S70, calculating the accumulated electric field under the influence of the sea surface light beam influence factor, obtaining the electric field intensity, and recording and saving it.

[0014] The above scheme is mainly aimed at the absorption and scattering effects of vortex light when it is transmitted in the underwater channel of the ocean. Photons are used as the carrier of light information, and the electric field information, position and direction of photons after each Mie scattering are recorded, so as to more accurately calculate the propagation and scattering process of light underwater, which makes up for the shortcomings of the existing simulation method. In addition, the electric field intensity E of the vortex light beam on the vortex light when it is transmitted across the sea surface is obtained by combining the influence of the undulating sea surface on the light beam. ins , which provides new ideas and methods for the transmission of light beams across media.

[0015] In a second aspect, the present invention provides a vortex light cross-sea surface transmission simulation system based on the electric field Monte Carlo method, comprising:

[0016] The initialization module is used to load photons and perform initialization settings, including setting the initial coordinates of the photons, initial direction cosines, initial parallel components of the complex electric field and initial vertical components of the complex electric field. The initial parallel components of the complex electric field and initial vertical components of the complex electric field are set to and E 2 = 0, where i represents the imaginary unit, l represents the topological charge of the vortex beam, is the azimuth;

[0017] The position change detection module is used to calculate the position change of photons during random walk in the channel;

[0018] The first judgment module is used to judge whether the photon reaches the detection surface or has been scattered according to the position change of the photon, and if so, returns to the initialization module to simulate the scattering process of the next photon; if not, enters the first calculation module;

[0019] The first calculation module is used to calculate the absorption rate of photons and local orthogonal coordinate transformation;

[0020] The second judgment module is used to determine whether the photon survives by selecting a survival roulette wheel. If yes, it returns to the position change detection module to continue simulating the subsequent behavior of the photon. If no, the photon is no longer alive and enters the third judgment module;

[0021] The third judgment module is used to judge whether all photons have been calculated. If yes, it enters the second calculation module. If not, it returns to the initialization module to simulate the scattering process of the next photon.

[0022] The second calculation module is used to calculate the accumulated electric field under the influence of the sea surface light beam influence factor, obtain the electric field strength, and record and save it.

[0023] In a third aspect, the present invention provides a computer program product comprising computer-readable instructions, characterized in that the computer-readable instructions, when executed by a processor, implement the steps of the method for simulating vortex light transmission across the sea surface based on the electric field Monte Carlo method of the present invention.

[0024] In a fourth aspect, the present invention provides a computer-readable storage medium comprising computer-readable instructions, characterized in that when the computer-readable instructions are executed by a processor, the steps of the method for simulating the transmission of vortex light across the sea surface based on the electric field Monte Carlo method of the present invention are implemented.

[0025] In a fifth aspect, the present invention provides an electronic device, comprising: a memory storing program instructions; a processor connected to the memory, executing the program instructions in the memory, and implementing the steps in the method for simulating the transmission of vortex light across the sea surface based on the electric field Monte Carlo method of the present invention.

[0026] Compared with the prior art, the present invention has the following significant technical advantages:

[0027] In particular, in terms of forming an applicable system by combining the ocean and air interface, the present invention enhances the calculation accuracy of the light propagation process by recording the electric field information and position of photons in detail. This recording method allows the electric field information after each Mie scattering to be retained, thereby accurately reflecting the changes of the light beam during the propagation process, especially in the transmission process of light from underwater to the air interface and from the air interface to underwater, which can achieve effective simulation.

[0028] In addition, the present invention comprehensively considers the impact of sea surface fluctuations on the propagation path and intensity of the light beam, especially in the actual marine environment, where sea surface fluctuations can significantly affect the propagation of light. Through a comprehensive analysis of these factors, the present invention can accurately predict the electric field intensity of vortex light in cross-sea transmission, making the system applicable to bidirectional transmission scenarios between the ocean and air interface.

[0029] In order to more effectively handle complex scattering and absorption problems, the present invention adopts the electric field Monte Carlo method, which can reflect the impact of multiple scattering effects on electric field intensity. In the initialization and updating process of the electric field, the formula adopted by the present invention plays an important role. The electric field initialization formula is used to set the electric field state before the photon enters the scattering medium, and its special effect is to provide a clear starting point for subsequent propagation and scattering processes, so that the simulation of the light field is more accurate. During initialization, the electric field distribution is affected by the incident beam type (such as plane wave or vortex beam), ensuring that the model can truly reflect the actual situation, which provides a basis for effective simulation and helps researchers better understand the propagation characteristics of light in the medium.

[0030] Secondly, the electric field update formula of photons after scattering updates the changes in the electric field of photons after each scattering, reflecting the changes in the electric field intensity after the photons interact with the scattering medium in real time. This formula takes into account factors such as the scattering angle and scattering amplitude to ensure the dynamic update of the electric field information. This dynamic update mechanism not only improves the accuracy of the model, but also effectively simulates the impact of multiple scattering on light propagation, and more realistically reflects the attenuation characteristics and propagation path of the light beam, thereby achieving two-way applicability from the ocean to the air interface and from the air interface to the ocean interface.

[0031] In summary, the present invention forms a method and system suitable for two transmission scenarios by combining the ocean and air interfaces, and has the technical advantages of high efficiency, accuracy and reliability.

[0032] For other advantages of the present invention, please refer to the relevant description in the embodiment section. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 This is a flow chart of a method for simulating the transmission of vortex light across the sea surface based on the electric field Monte Carlo method as exemplified in the embodiments.

[0035] Figure 2a , Figure 2b , Figure 2c The light field distribution diagrams of the changes in beam intensity when there is no wind, wind speed is 6m / s, and wind speed is 8m / s.

[0036] Figure 3 It is a block diagram of the composition of the vortex light cross-sea surface transmission simulation system based on the electric field Monte Carlo method as an example in the embodiments.

[0037] Figure 4 FIG. 4 is a block diagram of the electronic device in the embodiment. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0039] See also Figure 1 In this embodiment, a method for simulating vortex light transmission across the sea surface based on the electric field Monte Carlo method is provided, comprising the following steps:

[0040] S10, loading photons and performing initialization settings, including setting the initial coordinates and initial direction cosines of the photons.

[0041] When using EMC simulation method to simulate the transmission of OAM (vortex light) beam in underwater scattering channel, one of the most important steps is to set the initial coordinates of photons. Assume that the axial coordinate of the initial emission is z = 0. In the polar coordinate system, the coordinates of the photons on the initial emission plane need to be set. For selection, ρ is related to the radial distribution characteristics of the OAM beam intensity, and the size of the intensity distribution with ρ determines the probability of extracting ρ.

[0042] The intensity distribution of the OAM beam on the emission surface is related to the radial basis function. For a Bessel-Gaussian beam, its radial basis function can be expressed as:

[0043]

[0044] Among them, E 0 is a constant, ω 0 is the beam waist radius, k ρ is the radial wave vector, l is the order of the Bessel-Gaussian beam, i.e., the topological charge, which can be any integer, and ρ is the initial radial coordinate, where E 0 ,ω 0 , k ρ , l can be set directly. For the convenience of observation, the beam is set to a circular beam distribution pattern. J l (·) represents the first-kind Bessel function of order l, and the “·” in the function represents the parameter.

[0045] According to this radial basis function, the normalized light intensity density function can be obtained:

[0046]

[0047] This normalized light intensity density function describes the radial light intensity distribution of the OAM beam on the emission surface. In the simulation, the light intensity density function can be sampled by the rejection algorithm to determine the initial radial coordinate ρ of each photon.

[0048] The random sampling of the emitted photons ρ by the EMC method obeys the probability density distribution corresponding to the normalized light intensity density function. For the convenience of sampling, the cutoff radius of the incident OAM beam is set to R m , let ρ be [0,R m ] is uniformly distributed within the range of . The more photons are emitted at the position ρ of the normalized light intensity density function I(ρ), the greater the probability of emission.

[0049] Therefore, the rejection algorithm is used to select the ρ of the input OAM beam. 0 The sampling process is as follows:

[0050] (1) Generate a random number χ, satisfying χ~U(0,1), and calculate a radial coordinate ρ 0 =χR m .

[0051] (2) Generate a random number satisfy If satisfied Then accept this ρ 0 .

[0052] For the azimuth For sampling, since the OAM beam has radial symmetry in the polar coordinate system, a uniform distribution between 0 and 2π can be directly adopted.

[0053] In addition, in order to ensure the initial electric field component of the photon, according to the characteristics of the OAM beam, the initial parallel component of the complex electric field and the vertical component of the complex electric field are set to and E 2 =0, where i represents the imaginary unit and l represents the topological charge of the vortex beam.

[0054] Using the Cartesian coordinate system, the initial coordinates of the photon can be expressed as:

[0055]

[0056] The initial direction cosines can be expressed as:

[0057]

[0058] where θ 0 and are the elevation and azimuth angles in the direction of photon emission, θ 0 They are obtained by the following formulas:

[0059]

[0060] where r 3 、r 4 Represents a random number between 0 and 1, uniformly distributed within 0 to 1, θ 1 is the divergence angle of the light beam.

[0061] S20, calculate the position change of the photon during its random walk in the channel.

[0062] Define the position coordinates of the photon before scattering as (x, y, z), the position coordinates after scattering as (x′, y′, z′), the direction cosines of the photon before scattering as (u, v, w), and assume that the propagation distance of the photon after one scattering is l sct According to Beer's Law, the photon scattering step is expressed as l sct =-ln(ζ) / Q sca , where Q sca is the scattering coefficient, and ζ is a random number that is uniformly distributed between 0 and 1. Therefore, the photon is transmitted from the position coordinates (x, y, z) before scattering to a distance l. scc After that, the position coordinates (x′, y′, z′) can be expressed as:

[0063] x′=x+ul sct

[0064] y′=y+vl sct

[0065] z′=z+wl sct ;

[0066] The direction cosines after scattering can be updated as follows:

[0067]

[0068] θ, are the scattering angle and azimuth, respectively.

[0069] As photons are continuously scattered, their scattering angle and azimuth will change, and they are updated every time they are scattered.

[0070] In different scattering angle ranges, select the most appropriate phase function. The commonly used HG phase function has fewer parameters, so it is simple and easy to use. The expression of the HG phase function is:

[0071]

[0072] The scattering angle θ can be set by the phase function distribution law:

[0073]

[0074] θ is the scattering angle; g is the asymmetry factor, whose size affects the ratio of forward scattering to backscattering. ζ is a random number that is uniformly distributed between 0 and 1. Given ζ and g, the scattering angle θ can be calculated.

[0075] The azimuth angle is uniformly distributed between 0-2π and can be expressed as Used in the scatter loop.

[0076] S30, judging whether the photon has reached the detection surface or has been scattered according to the change in the position of the photon, if so, returning to step S10 to simulate the scattering process of the next photon; if not, entering step S40.

[0077] For example, suppose a photon starts from the origin (0.1, 0.5, 0), and after several propagations, its position is updated to (1, 1, 6). In this case, because the z coordinate (6) is greater than z_d (5), it is judged that the photon has reached the detection surface.

[0078] If the scattering angle is not zero, it is determined that scattering has occurred.

[0079] S40, calculate the absorption rate of photons, local coordinates and other parameters, and then enter step S50.

[0080] When photons interact with spherical dielectric particles, part of the energy will be absorbed and scattered by the dielectric particles. The particle scattering coefficient, absorption coefficient, and extinction coefficient are Q sca , Q abs , Q ext , which is expressed as follows:

[0081]

[0082] Q ass =Q ext -Q sca .

[0083] a N With b N They are Mie coefficient, symbol represents the real part, x r Represents the relative size of scattering spherical particles. N represents terms of different orders, which are used to represent the contribution of spherical harmonics of different orders. By accumulating these terms of different orders, parameters such as scattering, absorption and extinction can be described more accurately.

[0084] In order to represent the absorption of the light beam during propagation, the weight W of the photon after each scattering can be adjusted a To achieve this, the weight change can be expressed as W a =W(1-Qsca / Q ext ), Q sca / Q ext represents the single scattering albedo, which represents the proportion of scattering in extinction, W is the initial weight of the photon, and the absorption rate is

[0085] The local orthogonal coordinate system of the photon before scattering is recorded as (m, n, s), and the coordinate system after interaction with the medium particles is recorded as (m', n', s'). m and n are the parallel component and perpendicular component of the electric field before scattering, respectively, and are unit vectors in the direction of the scattering plane relative to the last scattering. The electric field component is the real part of the complex electric field component. The electric field component describes the actual amplitude of the electric field at the position, which can be directly measured by physical measurement instruments. The complex electric field component provides complete amplitude and phase information. s is the direction of motion of the photon before scattering (which can be called the incident direction), and s' is the direction of motion of the photon after scattering with the medium particles (which can be called the scattering direction). The scattering direction s' and the incident direction s determine the scattering plane. The unit vectors m' and n' are the parallel component of the scattered light parallel to the scattering plane and the perpendicular component perpendicular to the scattering plane, respectively, and satisfy m'×n'=s'. E 1 、E 1 ′、E 2 、E 2 ′ are respectively the complex electric field components in the direction parallel to the electric field before scattering, the complex electric field components in the direction parallel to the electric field after scattering, the complex electric field components in the direction perpendicular to the electric field before scattering, and the complex electric field components in the direction perpendicular to the electric field after scattering. The local coordinate transformation rules of photons before and after scattering can be abstracted by vector operations and can be expressed in matrix form. Each time a photon is scattered, the change of the local coordinate system satisfies the following relationship:

[0086]

[0087] Where θ represents the scattering angle, Indicates the azimuth.

[0088] Similarly, the update of the complex electric field after the photon is scattered can be expressed as:

[0089]

[0090] Among them, S 1 and S 2 is the scattering amplitude function about the scattering angle θ, which is related to the scattering coefficient and the scattering angle function. According to the Mie scattering theory, they can be expressed as:

[0091]

[0092] where a N With b Nare Mie coefficients, which are functions related to the actual size of the scattering medium particles, the wavelength of the incident light, and the complex refractive index of the scattering medium particles, but have nothing to do with the scattering angle θ. N With τ N is the scattering angle function and is only related to the scattering angle θ. They can be expressed as:

[0093]

[0094] Among them, x r =πd / λ, which represents the relative particle size of the scattering spherical particles, where d is the actual diameter of the particle, in meters, and λ is the wavelength. The complex refractive index of the scattering spherical particles is: n sct =n real +i*n imag , where the real part n real Related to the scattering effect of medium particles, the imaginary part n imag Related to the absorption of medium particles, n imag When it is not 0, it means that the photon will be absorbed by the medium particles and cause energy attenuation. N (x) and ξ N (x) are half-integer order Bessel functions and second-order Hankel functions, respectively. N (cosθ) and P N ′(cosθ) are the Legendre function and the first-order associated Legendre function with respect to cosθ respectively. Indicates along The intensity normalization factor of the scattered light propagating in a certain direction is expressed as:

[0095]

[0096] Among them, the symbol Indicates taking the real part, * indicates taking the conjugate, is the azimuth, and at the same time |E 1 | 2 +|E 2 | 2 =1.

[0097] S50, determine whether the photon survives by selecting through the survival roulette wheel, if yes, return to step S20 and continue to simulate the subsequent behavior of the photon, if no, the photon is no longer alive, and enter step S60.

[0098] When the photon does not reach the receiving surface during the transmission process, the photon weight value will continue to decrease as the photon moves. When it is less than the set annihilation value, it means that the photon is annihilated during the movement and is not recorded on the receiving surface. Because even when the photon reaches the receiving surface, the contribution to the beam intensity is almost negligible. Ignoring the annihilated photons can speed up the execution efficiency of the program, that is, speed up the simulation efficiency. When the photon reaches the receiving surface and the weight is greater than the annihilation value, the photon stops moving and records the accumulated electric field information.

[0099] S60, determine whether all photons have been calculated, if yes, proceed to step S70, if not, return to step S10 to simulate the scattering process of the next photon.

[0100] S70, calculating the transmission coefficient and the sea surface light beam influence factor and applying them to the accumulated electric field to obtain the electric field strength, and recording and saving it.

[0101] After the photon is scattered by the medium particles n times, its final local orthogonal coordinate system is (m (n) ,n (n) ,s (n) ), for the convenience of statistics, the final motion direction of all photons is limited to s (n) All (u d ,v d ,w d )=(0,0,1), that is, it propagates in the positive direction of the z axis and reaches the detection surface. At this time, m (n) and n (n) The parallel and perpendicular electric field components in the direction are The corresponding electric field components in the x, y, and z directions can be according to Vector transformation is obtained. Taking into account the interaction between photons and scattering media and the phase delay caused by the propagation of scattering media, the electric field components in the x, y, and z directions after photon superposition can be expressed as:

[0102]

[0103] Where G is the x, y, and z directions, k is the wave number, l is the wave number, (n) is the total path length traveled by the photon after being scattered n times.

[0104] In this embodiment, the detection surface is set at z=z d The actual photon reaches the final scattering position after n scatterings. The coordinate in the z-axis direction is z (n) Generally speaking, the photon will not fall directly on the detection surface (the z-axis coordinate is z d ) is received, i.e. z(n) >z d or (n) ≤z d In this case, it is necessary to consider the phase extension from the final scattering position of the photon to the detection surface, which can be expressed as In addition, there is an uncounted scattering process from the final scattering position to the detection position, which causes the attenuation of photon energy. Therefore, a weight attenuation factor can be set as To equivalent the attenuation effect, the scattering cross section l sct is the random step size for scattering.

[0105] Taking all the above factors into consideration, the electric field components of the photons received by the detection surface in the x, y, and z directions can be expressed as:

[0106]

[0107] w d represents the direction cosine of the photon arriving at the receiving plane.

[0108] According to the Fresnel formula, the total transmittance T of the light beam transmitted from underwater to the sea surface is up for:

[0109] T up =T wa1 T wa2 ;

[0110] Where T wa1 Indicates the transmittance of the air-sea interface itself, satisfying α represents the incident angle of the light beam from the sea-air interface, and β represents the refraction angle. According to the refraction theorem, the expression of the refraction angle is n 1 、n 2 Represent the refractive index of seawater and air respectively. wa2 It indicates the transmittance caused by foam and other factors on the sea surface. When the wind speed p≤9m / s, T wa2 =1-1.2×10 -5 ×p 3.3 , when the wind speed is p>9m / s, T wa2 =1-1.2×10 -5 ×p 3.3 ×(0.225p-0.99).

[0111] The electric field components in the x, y, and z directions of the Bessel-Gaussian beam after it passes through the sea surface are:

[0112]

[0113] in represents the electric field of each component of the Bessel-Gaussian beam after the beam from below the sea surface is scattered multiple times by the seawater. is the wave number of the Bessel-Gaussian beam, λ is the beam wavelength, z h represents the sea surface height fluctuation function, n 1 is the refractive index of seawater, T is the total transmittance. The total electric field intensity E ins The size can be expressed using the following formula:

[0114]

[0115] Where E x 、E y 、E z are the electric field components in the x, y, and z directions respectively.

[0116] We have already discussed the process of light propagating underwater and passing through the ocean interface upward. Now, when light is transmitted from the air and transmitted downward through the ocean interface, the transmission process is:

[0117] S100, loading photons and performing initialization settings, including setting initial coordinates and initial direction cosines of the photons.

[0118] When using EMC simulation method to simulate the transmission of OAM (vortex light) beam in air scattering channel, one of the most important steps is to set the initial coordinates of photons. Assume that the axial coordinate of the initial emission is z = 0. In the polar coordinate system, the coordinates of the photons on the initial emission plane need to be set. For selection, ρ is related to the radial distribution characteristics of the OAM beam intensity, and the size of the intensity distribution with ρ determines the probability of extracting ρ.

[0119] The intensity distribution of the OAM beam on the emission surface is related to the radial basis function. For a Bessel-Gaussian beam, its radial basis function can be expressed as:

[0120]

[0121] Among them, E 0 is a constant, ω 0 is the beam waist radius, k ρ is the radial wave vector, l is the order of the Bessel-Gaussian beam, i.e., the topological charge, which can be any integer, and ρ is the initial radial coordinate, where E 0 ,ω 0 , k ρ , l can be set directly. For the convenience of observation, the beam is set to a circular beam distribution pattern. J l (·) represents the first-kind Bessel function of order l, and the “·” in the function represents the parameter.

[0122] According to this radial basis function, the normalized light intensity density function can be obtained:

[0123]

[0124] This normalized light intensity density function describes the radial light intensity distribution of the OAM beam on the emission surface. In the simulation, the light intensity density function can be sampled by the rejection algorithm to determine the initial radial coordinate ρ of each photon.

[0125] The random sampling of the emitted photons ρ by the EMC method obeys the probability density distribution corresponding to the normalized light intensity density function. For the convenience of sampling, the cutoff radius of the incident OAM beam is set to R m , let ρ be [0,R m ] is uniformly distributed within the range of . The more photons are emitted at the position ρ of the normalized light intensity density function I(ρ), the greater the probability of emission.

[0126] Therefore, the rejection algorithm is used to select the ρ of the input OAM beam. 0 The sampling process is as follows:

[0127] (1) Generate a random number χ, satisfying χ~U(0,1), and calculate a radial coordinate ρ 0 =χR m .

[0128] (2) Generate a random number satisfy If satisfied Then accept this ρ 0 .

[0129] For the azimuth For sampling, since the OAM beam has radial symmetry in the polar coordinate system, a uniform distribution between 0 and 2π can be directly adopted.

[0130] In addition, in order to ensure the initial electric field component of the photon, according to the characteristics of the OAM beam, the initial complex electric field parallel component and the complex electric field vertical component are set to and E 2 =0, where i represents the imaginary unit and l represents the topological charge of the vortex beam.

[0131] Using the Cartesian coordinate system, the initial coordinates of the photon can be expressed as:

[0132]

[0133] The initial direction cosines can be expressed as:

[0134]

[0135] where θ 0 and are the elevation and azimuth angles in the direction of photon emission, θ 0 They are obtained by the following formulas:

[0136]

[0137] where r 3 、r 4 Represents a random number between 0 and 1, uniformly distributed within 0 to 1, θ 1 is the divergence angle of the light beam.

[0138] S200, when the photon randomly walks in the channel, the position change of the photon is calculated.

[0139] Define the position coordinates of the photon before scattering as (x, y, z), the position coordinates after scattering as (x′, y′, z′), the direction cosines of the photon before scattering as (u, v, w), and assume that the propagation distance of the photon after one scattering is l sct According to Beer's Law, the photon scattering step is expressed as l sct =-ln(ζ) / Q sca , where Q sca is the scattering coefficient, and ζ is a random number that is uniformly distributed between 0 and 1. Therefore, the photon is transmitted from the position coordinates (x, y, z) before scattering to a distance l. scc After that, the position coordinates (x′, y′, z′) can be expressed as:

[0140] x′=x+ul sct

[0141] y′=y+vl sct

[0142] z′=z+wl sct ;

[0143] The direction cosines after scattering can be updated as follows:

[0144]

[0145] θ, are the scattering angle and azimuth, respectively.

[0146] As photons are continuously scattered, their scattering angle and azimuth will change, and they are updated every time they are scattered.

[0147] In different scattering angle ranges, select the most appropriate phase function. The commonly used HG phase function has fewer parameters, so it is simple and easy to use. The expression of the HG phase function is:

[0148]

[0149] The scattering angle θ can be set by the phase function distribution law:

[0150]

[0151] θ is the scattering angle; g is the asymmetry factor, whose size affects the ratio of forward scattering to backscattering. ζ is a random number that is uniformly distributed between 0 and 1. Given ζ and g, the scattering angle θ can be calculated.

[0152] The azimuth angle is uniformly distributed between 0-2π and can be expressed as Used in the scatter loop.

[0153] S300, judging whether the photon has reached the detection surface or has been scattered according to the change in the position of the photon, if so, returning to step S100 to simulate the scattering process of the next photon; if not, entering step S400.

[0154] For example, suppose a photon starts from the origin (0.1, 0.5, 0), and after several propagations, its position is updated to (1, 1, 6). In this case, because the z coordinate (6) is greater than z_d (5), it is judged that the photon has reached the detection surface.

[0155] If the scattering angle is not zero, it is determined that scattering has occurred.

[0156] S400, calculate the absorption rate of photons, local coordinates and other parameters, and then enter step S500.

[0157] When photons interact with spherical dielectric particles, part of the energy will be absorbed and scattered by the dielectric particles. The particle scattering coefficient, absorption coefficient, and extinction coefficient are Q sca , Q abs , Q ext , which is expressed as follows:

[0158]

[0159] Q ass =Q ext -Q sca .

[0160] a N With b N They are Mie coefficient, symbol represents the real part, x r Represents the relative size of scattering spherical particles. N represents terms of different orders, which are used to represent the contribution of spherical harmonics of different orders. By accumulating these terms of different orders, parameters such as scattering, absorption and extinction can be described more accurately.

[0161] In order to represent the absorption of the light beam during propagation, the weight W of the photon after each scattering can be adjusted a To achieve this, the weight change can be expressed as W a =W(1-Q sca / Q ext ), Q sca / Q ext represents the single scattering albedo, which represents the proportion of scattering in extinction, W is the initial weight of the photon, and the absorption rate is

[0162] The local orthogonal coordinate system of the photon before scattering is recorded as (m, n, s), and the coordinate system after interaction with the medium particles is recorded as (m', n', s'). m and n are the parallel component and perpendicular component of the electric field before scattering, respectively, and are unit vectors in the direction of the scattering plane relative to the last scattering. The electric field component is the real part of the complex electric field component. The electric field component describes the actual amplitude of the electric field at the position, which can be directly measured by physical measurement instruments. The complex electric field component provides complete amplitude and phase information. s is the direction of motion of the photon before scattering (which can be called the incident direction), and s' is the direction of motion of the photon after scattering with the medium particles (which can be called the scattering direction). The scattering direction s' and the incident direction s determine the scattering plane. The unit vectors m' and n' are the parallel component of the scattered light parallel to the scattering plane and the perpendicular component perpendicular to the scattering plane, respectively, and satisfy m'×n'=s'. E 1 、E 1 ′、E 2 、E 2 ′ are respectively the complex electric field components in the direction parallel to the electric field before scattering, the complex electric field components in the direction parallel to the electric field after scattering, the complex electric field components in the direction perpendicular to the electric field before scattering, and the complex electric field components in the direction perpendicular to the electric field after scattering. The local coordinate transformation rules of photons before and after scattering can be abstracted by vector operations and can be expressed in matrix form. Each time a photon is scattered, the change of the local coordinate system satisfies the following relationship:

[0163]

[0164] Where θ represents the scattering angle, Indicates the azimuth.

[0165] Similarly, the update of the complex electric field after the photon is scattered can be expressed as:

[0166]

[0167] Among them, S 1 and S 2 is the scattering amplitude function about the scattering angle θ, which is related to the scattering coefficient and the scattering angle function. According to the Mie scattering theory, they can be expressed as:

[0168]

[0169] where a N With b N are Mie coefficients, which are functions related to the actual size of the scattering medium particles, the wavelength of the incident light, and the complex refractive index of the scattering medium particles, but have nothing to do with the scattering angle θ. N With τ N is a function of the scattering angle and is only related to the scattering angle θ, and can be expressed as:

[0170]

[0171] Among them, x r =πd / λ, which represents the relative particle size of the scattering spherical particles, where d is the actual diameter of the particle, in meters, and λ is the wavelength. The complex refractive index of the scattering spherical particles is: n sct =n real +i*n imag , where the real part n real Related to the scattering effect of medium particles, the imaginary part n imag Related to the absorption of medium particles, n imag When it is not 0, it means that the photon will be absorbed by the medium particles and cause energy attenuation. N (x) and ξ N (x) are half-integer order Bessel functions and second-order Hankel functions, respectively. N (cosθ) and P N ′(cosθ) are the Legendre function and the first-order associated Legendre function with respect to cosθ respectively. Indicates along The intensity normalization factor of the scattered light propagating in a certain direction is expressed as:

[0172]

[0173] Among them, the symbol Indicates taking the real part, * indicates taking the conjugate, is the azimuth, and at the same time |E 1 | 2 +E 2 | 2 =1.

[0174] S500, determine whether the photon survives by selecting through the survival roulette wheel, if yes, return to step S200, continue to simulate the subsequent behavior of the photon, if not, the photon is no longer alive, enter step S600.

[0175] When the photon does not reach the receiving surface during the transmission process, the photon weight value will continue to decrease as the photon moves. When it is less than the set annihilation value, it means that the photon is annihilated during the movement and is not recorded on the receiving surface. Because even when the photon reaches the receiving surface, the contribution to the beam intensity is almost negligible. Ignoring the annihilated photons can speed up the execution efficiency of the program, that is, speed up the simulation efficiency. When the photon reaches the receiving surface and the weight is greater than the annihilation value, the photon stops moving and records the accumulated electric field information.

[0176] S600, determine whether all photons have been calculated, if yes, go to step S700, if not, return to step S100 to simulate the scattering process of the next photon.

[0177] S700, calculate the transmission coefficient and the sea surface beam influence factor and apply them to the accumulated electric field to obtain the electric field strength, and record and save it.

[0178] After the photon is scattered by the medium particles n times, its final local orthogonal coordinate system is (m (n) ,n (n) ,s (n) ), for the convenience of statistics, the final motion direction of all photons is limited to s (n) All (u d ,v d ,w d )=(0,0,1), that is, it propagates in the positive direction of the z axis and reaches the detection surface. At this time, m (n) and n (n) The parallel and perpendicular electric field components in the direction are The corresponding electric field components in the x, y, and z directions can be according to Vector transformation is obtained. Taking into account the interaction between photons and scattering media and the phase delay caused by the propagation of scattering media, the electric field components in the x, y, and z directions after photon superposition can be expressed as:

[0179]

[0180] Where G is the x, y, and z directions, k is the wave number, l is the wave number, (n) is the total path length traveled by the photon after being scattered n times.

[0181] In this embodiment, the detection surface is set at z=z d The actual photon reaches the final scattering position after n scatterings. The coordinate in the z-axis direction is z (n) Generally speaking, the photon will not fall directly on the detection surface (the z-axis coordinate is z d) is received, i.e. z (n) >z d or (n) ≤z d In this case, it is necessary to consider the phase extension from the final scattering position of the photon to the detection surface, which can be expressed as In addition, there is an uncounted scattering process from the final scattering position to the detection position, which causes the attenuation of photon energy. Therefore, a weight attenuation factor can be set as To equivalent the attenuation effect, the scattering cross section l sct is the random step size for scattering.

[0182] Taking all the above factors into consideration, the electric field components of the photons received by the detection surface in the x, y, and z directions can be expressed as:

[0183]

[0184] w d represents the direction cosine of the photon arriving at the receiving plane.

[0185] From the Fresnel formula, we know that the total transmittance of the light beam through the sea surface is given by:

[0186] T down =T wa1 T wa2 ;

[0187] Where T wa1 Indicates the transmittance of the air-sea interface itself, satisfying α represents the incident angle of the light beam from the air-sea interface. According to the refraction theorem, the expression of the refraction angle is n 1 、n 2 Represent the refractive index of seawater and air respectively. wa2 It indicates the transmittance caused by sea surface materials (such as foam on the sea surface and other factors). When the wind speed p≤9m / s, T wa2 =1-1.2×10 -5 ×p 3.3 , when the wind speed is p>9m / s, T wa2 =1-1.2×10 -5 ×p 3.3 ×(0.225p-0.99).T down It is expressed as the total transmittance of the light beam transmitted downward from the air;

[0188] The electric field components in the x, y, and z directions of the Bessel-Gaussian beam after it passes through the sea surface are:

[0189]

[0190] in represents the electric field of each component of the Bessel-Gaussian beam after the beam is scattered multiple times through the air. is the wave number of the Bessel-Gaussian beam, λ is the beam wavelength, z h represents the sea surface height fluctuation function, n 1 is the refractive index of seawater, T is the total transmittance. The total electric field intensity E ins The size can be expressed using the following formula:

[0191]

[0192] Where E x 、E y 、E z are the electric field components in the x, y, and z directions respectively.

[0193] like Figure 2a , Figure 2b , Figure 2c As shown, Figure 2a , Figure 2b , Figure 2c The light field distribution of the change in beam intensity when there is no wind, wind speed of 6m / s, and wind speed of 8m / s. As the wind speed on the sea surface increases, the intensity distribution of the Bessel-Gaussian beam will gradually distort. When the wind speed on the sea surface reaches 8m / s, the light intensity distribution is seriously distorted. This is because the greater the wind speed on the sea surface, the lower the transmittance of the sea surface, and the transmitted light is also affected by the shielding of the sea surface itself. As the wind speed increases, this shielding effect becomes more significant. From the distribution diagram of the transmitted light intensity, the higher the wind speed on the sea surface, the more uneven the distribution of the laser transmission light intensity. Especially when the relative height difference of the sea surface is large, the transmission of light is significantly blocked, resulting in very little transmitted light.

[0194] In an experimental example, the emission beam uses a Bessel-Gaussian beam that is common and easy to generate in the laboratory. In order to balance the execution efficiency of the code and the simulation accuracy, the following parameters are used:

[0195]

[0196]

[0197] In the process of a light beam being transmitted from underwater to the sea surface or from air to underwater, it will experience multiple scatterings. Existing similar technologies have failed to effectively reflect this phenomenon. The present invention adopts the electric field Monte Carlo method to divide the light beam into multiple photons, simulating the multiple collisions of these photons with the scattering medium in the seawater during the propagation process, thereby truly reflecting the attenuation of the light beam intensity caused by multiple scatterings when the light beam is transmitted from underwater to the sea surface.

[0198] See also Figure 3 Based on the same inventive concept, this embodiment also provides a vortex light cross-sea surface transmission simulation system based on the electric field Monte Carlo method, including:

[0199] The initialization module is used to load photons and perform initialization settings, including setting the initial coordinates of the photons, initial direction cosines, initial parallel components of the complex electric field and initial vertical components of the complex electric field. The initial parallel components of the complex electric field and initial vertical components of the complex electric field are set to and E 2 = 0, where i represents the imaginary unit, l represents the topological charge of the vortex beam, is the azimuth;

[0200] The position change detection module is used to calculate the position change of photons during random walk in the channel;

[0201] The first judgment module is used to judge whether the photon reaches the detection surface or has been scattered according to the position change of the photon, and if so, returns to the initialization module to simulate the scattering process of the next photon; if not, enters the first calculation module;

[0202] The first calculation module is used to calculate the absorption rate of photons and local orthogonal coordinate transformation;

[0203] The second judgment module is used to determine whether the photon survives by selecting a survival roulette wheel. If yes, it returns to the position change detection module to continue simulating the subsequent behavior of the photon. If no, the photon is no longer alive and enters the third judgment module;

[0204] The third judgment module is used to judge whether all photons have been calculated. If yes, it enters the second calculation module. If not, it returns to the initialization module to simulate the scattering process of the next photon.

[0205] The second calculation module is used to calculate the accumulated electric field under the influence of the sea surface light beam influence factor, obtain the electric field strength, and record and save it.

[0206] The specific execution process of each component module in the above system can be found in the relevant description of the above method, which will not be repeated here.

[0207] like Figure 4 As shown, this embodiment also provides an electronic device, which may include a processor 41 and a memory 42, wherein the memory 42 is coupled to the processor 41. It is worth noting that this figure is exemplary, and other types of structures may be used to supplement or replace this structure to achieve data extraction, report generation, communication or other functions.

[0208] like Figure 4As shown, the electronic device may further include: an input unit 43, a display unit 44 and a power supply 45. It is worth noting that the electronic device does not necessarily have to include Figure 4 In addition, electronic devices may also include Figure 4 For components not shown, reference may be made to the prior art.

[0209] The processor 41 is sometimes also called a controller or an operation control, and may include a microprocessor or other processor devices and / or logic devices. The processor 41 receives inputs and controls the operations of various components of the electronic device.

[0210] The memory 42 may be, for example, one or more of a cache, a flash memory, a hard drive, a removable medium, a volatile memory, a non-volatile memory or other suitable devices, and may store information such as configuration information of the processor 41 and instructions executed by the processor 41. The processor 41 may execute the program stored in the memory 42 to implement information storage or processing. In one embodiment, the memory 42 also includes a buffer memory, i.e., a buffer, to store intermediate information.

[0211] An embodiment of the present invention further provides a computer program product, including computer-readable instructions. When the computer-readable instructions are executed in an electronic device, the program product enables the electronic device to execute the operation steps included in the method of the present invention.

[0212] An embodiment of the present invention further provides a storage medium storing computer-readable instructions, wherein the computer-readable instructions enable an electronic device to execute the operation steps included in the method of the present invention.

[0213] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0214] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0215] The above-described embodiments are only specific implementations of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications, replacements and improvements within the technical scope disclosed by the present invention, and these modifications, replacements and improvements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A method for simulating the transmission of vortex light across the sea surface based on the electric field Monte Carlo method, characterized in that: The following steps are involved: S10, loading photons and performing initialization settings, including setting the initial coordinates, initial direction cosines, initial parallel components of the complex electric field and initial vertical components of the complex electric field. The initial parallel components of the complex electric field and initial vertical components of the complex electric field are set to and E2 = 0, where i represents the imaginary unit, l represents the topological charge of the vortex beam, is the azimuth; S20, calculate the position change of the photon during random walk in the channel; S30, judging whether the photon has reached the detection surface or has been scattered according to the change in the position of the photon, if yes, returning to step S10 to simulate the scattering process of the next photon; if no, proceeding to step S40; S40, calculating the absorption rate of photons and local orthogonal coordinate transformation, and then proceeding to step S50; S50, determining whether the photon survives by selecting the survival roulette wheel, if yes, returning to step S20, continuing to simulate the subsequent behavior of the photon, if no, the photon no longer survives, entering step S60; S60, determining whether all photons have been calculated, if yes, proceeding to step S70, if no, returning to step S10 to simulate the scattering process of the next photon; S70, calculating the accumulated electric field under the influence of the sea surface light beam influence factor, obtaining the electric field intensity, and recording and saving it.

2. The method for simulating vortex light transmission across the sea surface based on the electric field Monte Carlo method according to claim 1 is characterized in that: In S10, the initial radial coordinate ρ0 is first sampled, and then the Cartesian coordinate system is used. The initial coordinate of the photon is expressed as: The initial direction cosines are expressed as: where θ0 and are the elevation and azimuth angles in the direction of photon emission; θ0 is obtained by the following formula: Where r3 and r4 represent random numbers between 0 and 1, which are evenly distributed within the range of 0 to 1, and θ1 is the divergence angle of the light beam.

3. The method for simulating vortex light transmission across the sea surface based on the electric field Monte Carlo method according to claim 2 is characterized in that: The process of sampling the initial radial coordinates of the input OAM beam using the rejection algorithm is as follows: (1) Generate a random number χ, satisfying χ~U(0,1), and calculate a radial coordinate ρ0=χR m ; (2) Generate a random number satisfy If satisfied Then accept this ρ0, where E0 is a constant, ω0 is the beam waist radius, k ρ is the radial wave vector, J l (·) represents the first-kind Bessel function of order l. The "·" in the function represents the parameters, E0, ω0, k ρ , l can be set directly.

4. The method for simulating vortex light transmission across the sea surface based on the electric field Monte Carlo method according to claim 1 is characterized in that: In S20, the position coordinates of the photon before scattering are defined as (x, y, z), the position coordinates after scattering are defined as (x′, y′, z′), and the direction cosines of the photon before scattering are defined as (u, v, w), thus: x′=x+ul sct y′=y+vl sct z′=z+wl sct ; The direction cosines are updated after scattering by: l sct is the propagation distance of the photon after one scattering, l sct =-ln(ζ) / Q sca , Q sca is the scattering coefficient, ζ is a random number that is uniformly distributed between 0 and 1; θ, are the scattering angle and azimuth, respectively.

5. The method for simulating vortex light transmission across the sea surface based on the electric field Monte Carlo method according to claim 1, characterized in that: In S40, the local orthogonal coordinate system of the photon before scattering is recorded as (m, n, s), and the coordinate system after interacting with the medium particle is recorded as (m', n', s'), m'×n'=s'; each time the photon is scattered, the change of the local coordinate system satisfies the following relationship: Where θ represents the scattering angle, Indicates azimuth; The update of the complex electric field after the photon is scattered can be expressed as: Wherein, E1, E1′, E2, and E2′ are respectively the complex electric field components in the parallel direction of the electric field before scattering, the complex electric field components in the parallel direction of the electric field after scattering, the complex electric field components in the vertical direction of the electric field before scattering, and the complex electric field components in the vertical direction of the electric field after scattering; S1 and S2 are the scattering amplitude functions with respect to the scattering angle θ, where a N With b N They are Mie coefficient, π N With τ N is the scattering angle function, Among them, x r =πd / λ, which represents the relative particle size of the scattering spherical particles, where d is the actual diameter of the particle, in meters, and λ is the wavelength. The complex refractive index of the scattering spherical particles is: n sct =n real +i*n imag , where n real represents the real part, n imag represents the imaginary part; ψ N (x) and ξ N (x) are half-integer order Bessel function and Hankel function, P N (cosθ) and P N ′(cosθ) are the Legendre function and the first-order associated Legendre function about cosθ, Indicates along The intensity normalization factor of the scattered light propagating in a certain direction is expressed as: Among them, the symbol means taking the real part, * means taking the conjugate, |E1| 2 +|E2| 2 =1.

6. The method for simulating vortex light transmission across the sea surface based on the electric field Monte Carlo method according to claim 5 is characterized in that: In S70, the electric field components of the photons received by the detection surface in the x, y, and z directions can be expressed as: in, m (n) and n (n) The parallel electric field component and the perpendicular electric field component in the direction, i is an imaginary unit, is the wave number of the Bessel-Gaussian beam, λ is the wavelength of the beam, l (n) is the total path length traveled by the photon after being scattered n times, represents the phase extension from the final scattering position of the photon to the detection surface, represents the photon energy weight attenuation factor; When the light beam is transmitted from underwater to the sea surface, the electric field components in the x, y, and z directions of the Bessel-Gaussian beam after passing through the sea surface are: T up =T wa1 T wa2 ; Where T wa1 Indicates the transmittance of the air-sea interface itself, satisfying α is the incident angle of the light beam from the sea-air interface, β is the refraction angle, T wa2 Indicates the transmittance caused by sea surface materials; z h represents the sea surface height fluctuation function, n1 and n2 represent the refractive index of seawater and air respectively, T up It represents the total transmittance of the light beam from underwater to the sea surface; When the light beam is transmitted from the air to the sea surface, the electric field components in the x, y, and z directions of the Bessel-Gaussian beam after passing through the sea surface are: T down =T wa1 T wa2 ; The total electric field strength E ins The size of is expressed using the following formula: Where E x 、E y 、E z are the electric field components in the x, y, and z directions respectively.

7. A vortex light cross-sea surface transmission simulation system based on the electric field Monte Carlo method, characterized in that: include: The initialization module is used to load photons and perform initialization settings, including setting the initial coordinates of the photons, initial direction cosines, initial parallel components of the complex electric field and initial vertical components of the complex electric field. The initial parallel components of the complex electric field and initial vertical components of the complex electric field are set to and E2 = 0, where i represents the imaginary unit, l represents the topological charge of the vortex beam, is the azimuth; The position change detection module is used to calculate the position change of photons during random walk in the channel; The first judgment module is used to judge whether the photon reaches the detection surface or has been scattered according to the position change of the photon, and if so, returns to the initialization module to simulate the scattering process of the next photon; if not, enters the first calculation module; The first calculation module is used to calculate the absorption rate of photons and local orthogonal coordinate transformation; The second judgment module is used to determine whether the photon survives by selecting a survival roulette wheel. If yes, it returns to the position change detection module to continue simulating the subsequent behavior of the photon. If no, the photon is no longer alive and enters the third judgment module; The third judgment module is used to judge whether all photons have been calculated. If yes, it enters the second calculation module. If not, it returns to the initialization module to simulate the scattering process of the next photon. The second calculation module is used to calculate the accumulated electric field under the influence of the sea surface light beam influence factor, obtain the electric field strength, and record and save it.

8. A computer program product comprising computer readable instructions, characterized in that: When the computer-readable instructions are executed by a processor, the steps in the method for simulating the transmission of vortex light across the sea surface based on the electric field Monte Carlo method described in any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium comprising computer-readable instructions, characterized in that: When the computer-readable instructions are executed by a processor, the steps in the method for simulating the transmission of vortex light across the sea surface based on the electric field Monte Carlo method described in any one of claims 1 to 6 are implemented.

10. An electronic device, characterized in that: include: Memory, which stores program instructions; A processor is connected to the memory and executes program instructions in the memory to implement the steps in the method for simulating vortex light transmission across the sea surface based on the electric field Monte Carlo method as described in any one of claims 1 to 6.

Images