A method and device for generating multi-beam perfect vortex spatial multiplexing and detecting patterns

Abstract

The present application discloses a method and device for spatial multiplexing generation and pattern detection of multiple perfect vortices, which relates to the field of light field control technology. The method includes determining a truncation factor according to beam parameters; the truncation factor is used to distinguish perfect vortex beams at different spatial positions; determining a concentric perfect vortex light field according to the truncation factor and beam parameters; determining a phase mask of the concentric perfect vortex according to the concentric perfect vortex light field; loading the phase mask into a spatial light modulator, and then passing through a Fourier lens to obtain a concentric perfect vortex; interfering the concentric perfect vortex with a spherical wave to obtain the light intensity after the concentric perfect vortex and the spherical wave interfere; and performing pattern detection according to the light intensity after the concentric perfect vortex and the spherical wave interfere. The present application realizes simultaneous manipulation of multiple particles, expands multiplexing means in the communication field, and improves multi-body quantum entanglement.

Description

Technical Field

[0001] The present application relates to the field of light field control technology, and in particular to a method and device for spatial multiplexing generation and pattern detection of multiple perfect vortex beams. Background Art

[0002] Vortex beams have orbital angular momentum due to their unique spiral wavefronts. In theory, orbital angular momentum has infinite eigenstates, and different modes have mutually orthogonal characteristics, making vortex beams a research hotspot in recent years. However, the spot size of vortex beams broadens as the value of topological charge increases, which seriously restricts the practical application of vortex beams. In 2013, Andrey S. Ostrovsky and other scholars proposed the concept of perfect vortex beams (Andrey S. Ostrovsky, Carolina Rickenstorff-Parrao, and Víctor Arrizón, “Generation of the “perfect” optical vortex using a liquid-crystal spatial lightmodulator” Optics. Letters, 38, 534-536, 2013). This type of beam can effectively overcome the disadvantage that the spot radius changes with the topological charge, making the spot size independent of the topological charge value. At present, most of the research on perfect vortex beams is focused on the single beam level, and there are few reports on the research of spatially multiplexed perfect vortex beams.

[0003] In 2018, Xuankun Li's team from Harbin Institute of Technology designed a perfect vortex array with spatially displaced distribution through the frequency shift method (Xuankun Li, Yan Li, Xinning Zeng and Yanhua Han, "Perfect optical vortex array for optical communication based on orbital angular momentum shift keying" Journal of Optics, 20, 125604, 2018). This study only discussed the situation under the same conditions for all perfect vortex radii, ignoring the influence of the perfect vortex radius parameters on the array; in 2023, Swati Gangwar et al. combined multiple convex lenses with different focal lengths with a prism system in space to achieve coaxial superposition of multiple perfect vortices in space (Swati Gangwar, VK Jaiswal, Ranjana Mehrotra, Shibu Saha, and Parag Sharma, "Generation of a spatially multiplexed perfect vortex beam for digital data transmission" Journal of Optics, 25, 085702, 2023), however, the optical path system of this method is complex and has extremely stringent requirements on the collimation of the optical path. The use of a multi-prism system causes a large loss of light beam energy, resulting in poor resistance of the optical path system to environmental disturbances, and the placement of the convex lens will seriously affect the quality of the generated light beam.

[0004] Therefore, based on the above problems, in order to achieve simultaneous manipulation of multiple particles, expand the means of multiplexing in the communication field, and improve multi-body quantum entanglement, it is urgent to provide a simple and efficient method for spatial multiplexing generation and pattern detection of multiple perfect vortexes. Summary of the invention

[0005] The purpose of this application is to provide a method and device for spatial multiplexing generation and pattern detection of multiple perfect vortexes, which can realize simultaneous manipulation of multiple particles, expand multiplexing means in the communication field, and improve multi-body quantum entanglement.

[0006] To achieve the above objectives, this application provides the following solutions:

[0007] In a first aspect, the present application provides a method for generating a multi-beam perfect vortex spatial multiplexing and pattern detection, the method comprising:

[0008] Determine a truncation factor according to beam parameters; the truncation factor is used to distinguish perfect vortex beams at different spatial positions; the beam parameters include: beam waist radius, width of the spot bright ring, radius of the perfect vortex beam, and topological charge carried by the beam;

[0009] Determine the concentric perfect vortex light field based on the cutoff factor and beam parameters;

[0010] determining a phase mask of a concentric perfect vortex according to the concentric perfect vortex light field;

[0011] The phase mask is loaded into the spatial light modulator and then passed through the Fourier lens to obtain a concentric perfect vortex;

[0012] Interfere the concentric perfect vortex with the spherical wave to obtain the light intensity after the interference of the concentric perfect vortex and the spherical wave;

[0013] Mode detection is performed based on the light intensity after interference between the concentric perfect vortex and the spherical wave.

[0014] Optionally, determining the truncation factor according to the beam parameters specifically includes:

[0015] Using the formula Determine the cutoff factor;

[0016] in, is the cutoff factor, From the inside out The radius of a superimposed perfect vortex, The extreme diameter.

[0017] Optionally, determining the concentric perfect vortex light field according to the truncation factor and the beam parameters specifically includes:

[0018] Using the formula Determine the concentric perfect vortex light field;

[0019] in, It is a concentric perfect vortex light field. represents polar coordinates, and represent the polar diameter and polar angle respectively, is the number of superimposed perfect vortex beams, Indicates A superimposed perfect vortex light field, From the inside out The radius of a superimposed perfect vortex, is the radius of the first superimposed perfect vortex.

[0020] Optionally, determining the phase mask of the concentric perfect vortex according to the concentric perfect vortex light field specifically includes:

[0021] Using the formula Determine the phase transfer function corresponding to the axicon ;

[0022] Using the formula Determine the spiral phase transfer function after superposition of concentric perfect vortices ;

[0023] Using the formula Determining the transfer function of concentric perfect vortices ;

[0024] Using the formula Determine the phase mask of concentric perfect vortices ;

[0025] in, represents the imaginary unit, represents the transverse wave vector component, From the inside out The topological charge of a superimposed perfect vortex is represents the remainder function, represents the vertex angle of the axicon, represents the refractive index of the axicon, represents the wave number, , represents the wavelength of the light beam, is a mathematical function.

[0026] Optionally, interfering the concentric perfect vortex with the spherical wave to obtain the light intensity after the interference of the concentric perfect vortex and the spherical wave specifically includes:

[0027] Determine the spherical wave light field;

[0028] The light intensity after the interference between the concentric perfect vortex and the spherical wave is determined based on the spherical wave light field and the concentric perfect vortex light field.

[0029] Optionally, determining the spherical wave light field specifically includes:

[0030] Using the formula Determine the spherical wave light field ;

[0031] in, is the amplitude constant, is the finite beam width term of the spherical wave, and the parameter , is the distance that the spherical wave propagates to the receiving screen, is the polar diameter, represents the imaginary unit, represents the wave number, is the beam waist radius.

[0032] Optionally, determining the light intensity after the interference between the concentric perfect vortex and the spherical wave according to the spherical wave light field and the concentric perfect vortex light field specifically includes:

[0033] Using the formula Determine the light intensity after interference between concentric perfect vortex and spherical wave ;

[0034] in, It is a concentric perfect vortex light field. To take the conjugate mode.

[0035] In a second aspect, the present application provides a multi-beam perfect vortex spatial multiplexing generation and pattern detection device, which is used to implement the multi-beam perfect vortex spatial multiplexing generation and pattern detection method, and the multi-beam perfect vortex spatial multiplexing generation and pattern detection device includes: a light source, a spatial filter, a polarizer, a first beam splitter prism, a second beam splitter prism, a spatial light modulator, a first reflector, a second reflector, a concentric perfect vortex capture device, a third reflector and a pattern detection device;

[0036] The light source emits a laser, which passes through a spatial filter and a polarizing plate in sequence and is then divided into two beams of equal energy by a first beam splitter prism; the first beam propagates along the original optical axis and passes through a second beam splitter prism; the second beam is folded 90° clockwise along the original optical axis and irradiates a liquid crystal panel of a spatial light modulator; the spatial light modulator is loaded with a phase mask of a concentric perfect vortex to obtain a modulated beam, the modulated beam is reflected by a first reflector and a second reflector in sequence and enters a second beam splitter prism, the beam passing through the second beam splitter prism passes through a concentric perfect vortex capture device to obtain a concentric perfect vortex; when the beam passing through the second beam splitter prism irradiates a third reflector, it is folded back to the second beam splitter prism after reflection, and then is reflected by the second beam splitter prism and passes through a mode detection device to obtain an interference pattern of a concentric perfect vortex and a spherical wave.

[0037] Optionally, the concentric perfect vortex capture device comprises: a first convex lens and a first CCD camera;

[0038] The first convex lens is used to perform Fourier transform on the regulated light beam to obtain a concentric perfect vortex, which is captured by the first CCD camera.

[0039] Optionally, the mode detection device comprises: a second convex lens and a second CCD camera;

[0040] The second convex lens is used to transform the received light beam into a concentric perfect vortex and a spherical wave respectively. The two transformed light beams interfere with each other and are captured by the second CCD camera.

[0041] According to the specific embodiments provided in this application, this application has the following technical effects:

[0042] The present application provides a method and device for spatial multiplexing generation and pattern detection of multiple perfect vortex beams. Concentric perfect vortices are generated by coaxially superimposing multiple perfect vortex beams, and a truncation factor is introduced for each perfect vortex beam to effectively avoid mutual interference between multiple vortices. The present application determines the truncation factor according to the beam parameters and avoids mutual interference between multiple vortices, so that the number of concentric perfect vortices, the size and sign of the topological charge of perfect vortices at different spatial positions can be independently controlled, thereby realizing simultaneous manipulation of multiple particles, expanding multiplexing methods in the communication field, and improving multi-body quantum entanglement, etc., and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 This is a schematic flow chart of a method for spatial multiplexing generation and pattern detection of multiple perfect vortex beams in one embodiment of the present application;

[0045] Figure 2 The two-dimensional light intensity distribution diagram of the perfect vortex obtained under different topological charge and size parameter values;

[0046] Figure 3 Design concept diagram for concentric perfect vortex and two-dimensional light intensity distribution diagram of concentric perfect vortex;

[0047] Figure 4 Design a flow chart for the concentric perfect vortex phase mask;

[0048] Figure 5 for Schematic diagram of the light intensity distribution after the perfect vortex of the mode interferes with the spherical wave;

[0049] Figure 6 This is the optical path diagram for concentric perfect vortex generation and mode detection;

[0050] Figure 7 Schematic diagram of the concentric perfect vortex light intensity distribution and pattern detection results. DETAILED DESCRIPTION

[0051] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0052] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0053] In an exemplary embodiment, Figure 1 As shown, a method for generating multiple perfect vortex spatial multiplexing and detecting patterns is provided, and the method includes the following S101 to S106. Among them:

[0054] S101, determining a truncation factor according to beam parameters; the truncation factor is used to distinguish perfect vortex beams at different spatial positions; the beam parameters include: beam waist radius, spot bright ring width, perfect vortex beam radius, and topological charge carried by the beam;

[0055] Using the formula Determine the cutoff factor;

[0056] in, is the cutoff factor, From the inside out The radius of a superimposed perfect vortex, The extreme diameter.

[0057] S102, determining a concentric perfect vortex light field according to a truncation factor and beam parameters;

[0058] In the cylindrical coordinate system, the light field expression of a perfect vortex beam is:

[0059] ;

[0060] In the formula, represents polar coordinates, and represent the polar diameter and polar angle respectively, represents the imaginary unit, is the beam waist radius, is the width of the bright ring of the light spot, is the radius of the perfect vortex beam, It represents the topological charge carried by the light beam, and its value can be any integer.

[0061] Multiple perfect vortex beams are coaxially superimposed, assuming that the beam parameters are and If the outside and inside remain consistent, the light field expression after superposition is:

[0062] ;

[0063] In the formula, , From the inside out The topological charge of a superimposed perfect vortex is Indicates A superimposed perfect vortex light field, Indicates The radius of a superimposed perfect vortex, represents the number of superimposed perfect vortex beams.

[0064] In order to avoid mutual interference between multiple superimposed perfect vortex beams, a truncation factor is set to separate the perfect vortex beams at different spatial positions. The expression of the concentric perfect vortex light field after adding the truncation factor is as follows:

[0065] ;

[0066] in, It is a concentric perfect vortex light field. is the radius of the first superimposed perfect vortex.

[0067] S103, determining a phase mask of a concentric perfect vortex according to the concentric perfect vortex light field;

[0068] Using the formula Determine the phase transfer function corresponding to the axicon ;

[0069] Using the formula Determine the spiral phase transfer function after superposition of concentric perfect vortices ;

[0070] Using the formula Determining the transfer function of concentric perfect vortices ;

[0071] Using the formula Determine the phase mask of concentric perfect vortices ;

[0072] in, represents the imaginary unit, represents the transverse wave vector component, , From the inside out The topological charge of a superimposed perfect vortex is represents the remainder function, represents the vertex angle of the axicon, represents the refractive index of the axicon, represents the wave number, and , represents the wavelength of the light beam, is a mathematical function.

[0073] S104, loading the phase mask into the spatial light modulator, and then passing through the Fourier lens to obtain a concentric perfect vortex;

[0074] S105, interfering the concentric perfect vortex with the spherical wave to obtain the light intensity after the interference of the concentric perfect vortex and the spherical wave;

[0075] S105 specifically includes:

[0076] S51, determining the spherical wave light field;

[0077] Using the formula Determine the spherical wave light field ;

[0078] in, is the amplitude constant, is the finite beam width term of the spherical wave, and the parameter , is the distance that the spherical wave propagates to the receiving screen, is the polar diameter, represents the imaginary unit, represents the wave number, is the beam waist radius.

[0079] S52, determining the light intensity after the interference between the concentric perfect vortex and the spherical wave according to the spherical wave light field and the concentric perfect vortex light field.

[0080] Using the formula Determine the light intensity after interference between concentric perfect vortex and spherical wave ;

[0081] in, It is a concentric perfect vortex light field. To take the conjugate mode.

[0082] S106, performing mode detection based on the light intensity after the concentric perfect vortex and the spherical wave interfere.

[0083] Based on the same inventive concept, the embodiment of the present application also provides a multi-beam perfect vortex spatial multiplexing generation and pattern detection device for realizing the multi-beam perfect vortex spatial multiplexing generation and pattern detection method involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more multi-beam perfect vortex spatial multiplexing generation and pattern detection device embodiments provided below can refer to the limitations of the multi-beam perfect vortex spatial multiplexing generation and pattern detection method above, and will not be repeated here.

[0084] In an exemplary embodiment, Figure 6 As shown, a multi-beam perfect vortex spatial multiplexing generation and pattern detection device is provided, comprising: a light source, a spatial filter, a polarizer, a first beam splitter prism, a second beam splitter prism, a spatial light modulator, a first reflector, a second reflector, a concentric perfect vortex capture device, a third reflector, and a pattern detection device;

[0085] The light source emits a laser, which passes through a spatial filter and a polarizing plate in sequence and is then divided into two beams of equal energy by a first beam splitter prism; the first beam propagates along the original optical axis and passes through a second beam splitter prism; the second beam is folded 90° clockwise along the original optical axis and irradiates a liquid crystal panel of a spatial light modulator; the spatial light modulator is loaded with a phase mask of a concentric perfect vortex to obtain a modulated beam, the modulated beam is reflected by a first reflector and a second reflector in sequence and enters a second beam splitter prism, the beam passing through the second beam splitter prism passes through a concentric perfect vortex capture device to obtain a concentric perfect vortex; when the beam passing through the second beam splitter prism irradiates a third reflector, it is folded back to the second beam splitter prism after reflection, and then is reflected by the second beam splitter prism and passes through a mode detection device to obtain an interference pattern of a concentric perfect vortex and a spherical wave.

[0086] The light source is a semiconductor laser with a wavelength of 532nm;

[0087] The spatial filter is used to filter out stray light and shape the laser beam to obtain an approximate plane wave;

[0088] The concentric perfect vortex capture device comprises: a first convex lens and a first CCD camera;

[0089] The first convex lens is used to perform Fourier transform on the regulated light beam to obtain a concentric perfect vortex, which is captured by the first CCD camera, so that the light intensity distribution of the concentric perfect vortex can be observed;

[0090] The mode detection device comprises: a second convex lens and a second CCD camera;

[0091] The second convex lens is used to transform the received light beam into a concentric perfect vortex and a spherical wave respectively. The two converted light beams interfere with each other and are captured by the second CCD camera. The interference pattern of the concentric perfect vortex and the spherical wave can be observed, thereby realizing the pattern detection of the concentric perfect vortex.

[0092] This application not only strictly derives the light beam generation and detection process in theory, but also designs the corresponding optical path. The designed optical path is easy to build and can simultaneously realize the generation and pattern detection of concentric perfect vortices. The idea of ​​coaxial superposition of multiple perfect vortex beams is used to generate concentric perfect vortices, and a truncation factor is introduced for each perfect vortex beam to effectively avoid mutual interference between multiple vortices. The beam parameters are independently and freely regulated as needed, and it is expected to be used in fields such as multi-particle manipulation, optical communication, etc. with multiple degrees of freedom.

[0093] The following is described by means of specific embodiments. Figure 2 The beam radius is given m. m, and topological charge , The intensity distribution of perfect vortex beams in the case of two-by-two combinations is as follows: Figure 2 It can be seen that the spot size of the perfect vortex beam is not affected by the topological charge, but only by There is a positive correlation.

[0094] like Figure 3 Part (a) of the paper gives the design idea of ​​a concentric perfect vortex, assuming that the beam parameters are and Keep the outside consistent, and superimpose multiple perfect vortex beams coaxially in an order from the inside to the outside; set the number of superimposed perfect vortex beams , the topological charges of the beam from inside to outside are , , , , , , , , m, , the above parameters remain unchanged unless otherwise specified, and the following is obtained: Figure 3 Part (b) shows the light intensity distribution of the concentric perfect vortex.

[0095] like Figure 4 As shown in the figure, a flow chart of the design of concentric perfect vortex phase mask is given. Figure 4 Part (a) and Figure 4 The (b) part indicates that the truncation factor is not set and the truncation factor is set. The phase distribution of the last 8 perfect vortex beams after coaxial superposition. Comparison shows that the vortex phase on each ring becomes more uniform by adding the truncation factor. Figure 4 Part (c) gives the , , Phase distribution diagram of the axicon when . Figure 4 Part (d) of Figure 4 Part (e) shows the phase mask distribution obtained by combining the perfect vortex with the aconic lens. By loading the generated phase mask onto the spatial light modulator, the concentric perfect vortex control can be preliminarily achieved.

[0096] like Figure 5 Shown m, topological charge respectively , , , The interference pattern obtained when Figure 5 The two-dimensional and three-dimensional distribution of the interference pattern is shown in Figure 2. From the interference results, we can see that the perfect vortex beam is split from the original bright ring into multiple rotating bright spots, and the number of bright spots is exactly the same as the value of the topological charge. Therefore, the size of the topological charge can be obtained from the number of bright spots in the interference pattern; and the rotation direction of the bright spot after the splitting is related to the positive and negative signs of the topological charge. Specifically, the observation Figure 5 From the image in the standard dotted circle, we can see that when the topological charge is a negative integer, the bright spot rotates counterclockwise from outside to inside, and when the topological charge is positive, the bright spot rotates clockwise from outside to inside. Therefore, the topological charge sign information can be obtained based on the rotation direction of the bright spot after interference. In this way, the topological charge can be read based on the interference pattern of the perfect vortex and the spherical wave to achieve pattern detection.

[0097] The first CCD camera captures the light intensity distribution of the concentric perfect vortex as shown below: Figure 7 As shown in part (a), a concentric perfect vortex is produced.

[0098] The interference fringes are captured by the second CCD camera, and the interference pattern of the concentric perfect vortex and the spherical wave can be observed, such as Figure 7 As shown in part (b) of .

[0099] use Figure 6 The pattern obtained by the device after the concentric perfect vortex and the spherical wave interfere ( Figure 7 First, observe the number of concentric rings in the interference pattern. Figure 7 It is easy to read the number 8 in part (b), so the interference result is obtained by the coaxial superposition of 8 perfect vortex beams. The topological charge of the concentric perfect vortex from the inside to the outside is ; Then, the interference result is cut into 8 concentric rings from the inside to the outside, corresponding to Figure 7 The image shown in part (c) of the figure is shown from right to left; finally, the rotation direction and number of the interference bright spots of each intercepted image are observed in turn. When the bright spot rotates counterclockwise, the topological charge is negative, and when it rotates clockwise, the topological charge is positive. The number of bright spots is counted to get the value of the topological charge, and the topological charge is finally read as , , , , , , , , thus achieving the pattern detection of concentric perfect vortices.

[0100] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0101] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A method for spatial multiplexing generation and pattern detection of multiple perfect vortex beams, characterized in that: The multi-beam perfect vortex spatial multiplexing generation and pattern detection method comprises: Determine a truncation factor according to beam parameters; the truncation factor is used to distinguish perfect vortex beams at different spatial positions; the beam parameters include: beam waist radius, width of the spot bright ring, radius of the perfect vortex beam, and topological charge carried by the beam; Determine the concentric perfect vortex light field based on the cutoff factor and beam parameters; determining a phase mask of a concentric perfect vortex according to the concentric perfect vortex light field; The phase mask is loaded into the spatial light modulator and then passed through the Fourier lens to obtain a concentric perfect vortex; Interfere the concentric perfect vortex with the spherical wave to obtain the light intensity after the interference of the concentric perfect vortex and the spherical wave; Mode detection is performed based on the light intensity after interference between the concentric perfect vortex and the spherical wave; Determining the truncation factor according to the beam parameters specifically includes: Using the formula Determine the cutoff factor; in, is the cutoff factor, From the inside out The radius of a superimposed perfect vortex, The extreme diameter.

2. The method for generating and detecting multiple perfect vortex spatial multiplexing patterns according to claim 1, characterized in that: The method of determining the concentric perfect vortex light field according to the truncation factor and the beam parameters specifically includes: Using the formula Determine the concentric perfect vortex light field; in, It is a concentric perfect vortex light field. represents polar coordinates, and represent the polar diameter and polar angle respectively, is the number of superimposed perfect vortex beams, Indicates A superimposed perfect vortex light field, From the inside out The radius of a superimposed perfect vortex, is the radius of the first superimposed perfect vortex.

3. The method for generating and detecting multiple perfect vortex space multiplexing patterns according to claim 2, characterized in that: The determining of the phase mask of the concentric perfect vortex according to the concentric perfect vortex light field specifically includes: Using the formula Determine the phase transfer function corresponding to the axicon ; Using the formula Determine the spiral phase transfer function after superposition of concentric perfect vortices ; Using the formula Determining the transfer function of concentric perfect vortices ; Using the formula Determine the phase mask of concentric perfect vortices ; in, represents the imaginary unit, represents the transverse wave vector component, From the inside out The topological charge of a superimposed perfect vortex is represents the remainder function, represents the vertex angle of the axicon, represents the refractive index of the axicon, represents the wave number, , represents the wavelength of the light beam, is a mathematical function.

4. The method for generating and detecting multiple perfect vortex spatial multiplexing patterns according to claim 1, characterized in that: The interfering the concentric perfect vortex with the spherical wave to obtain the light intensity after the interference of the concentric perfect vortex with the spherical wave specifically includes: Determine the spherical wave light field; The light intensity after the interference between the concentric perfect vortex and the spherical wave is determined based on the spherical wave light field and the concentric perfect vortex light field.

5. The method for generating and detecting multiple perfect vortex spatial multiplexing patterns according to claim 4, characterized in that: The determining of the spherical wave light field specifically includes: Using the formula Determine the spherical wave light field ; in, is the amplitude constant, is the finite beam width term of the spherical wave, and the parameter , is the distance that the spherical wave propagates to the receiving screen, is the polar diameter, represents the imaginary unit, represents the wave number, is the beam waist radius.

6. The method for generating multi-beam perfect vortex spatial multiplexing and detecting patterns according to claim 5, characterized in that: The method of determining the light intensity after the interference between the concentric perfect vortex and the spherical wave according to the spherical wave light field and the concentric perfect vortex light field specifically includes: Using the formula Determine the light intensity after interference between concentric perfect vortex and spherical wave ; in, It is a concentric perfect vortex light field. To take the conjugate mode.

7. A multi-beam perfect vortex spatial multiplexing generation and pattern detection device, used to implement the multi-beam perfect vortex spatial multiplexing generation and pattern detection method according to any one of claims 1 to 6, characterized in that: The multi-beam perfect vortex spatial multiplexing generation and mode detection device comprises: a light source, a spatial filter, a polarizer, a first beam splitter prism, a second beam splitter prism, a spatial light modulator, a first reflector, a second reflector, a concentric perfect vortex capture device, a third reflector and a mode detection device; The light source emits a laser, which passes through a spatial filter and a polarizing plate in sequence and is then divided into two beams of equal energy by a first beam splitter prism; the first beam propagates along the original optical axis and passes through a second beam splitter prism; the second beam is folded 90° clockwise along the original optical axis and irradiates a liquid crystal panel of a spatial light modulator; the spatial light modulator is loaded with a phase mask of a concentric perfect vortex to obtain a modulated beam, the modulated beam is reflected by a first reflector and a second reflector in sequence and enters a second beam splitter prism, the beam passing through the second beam splitter prism passes through a concentric perfect vortex capture device to obtain a concentric perfect vortex; when the beam passing through the second beam splitter prism irradiates a third reflector, it is folded back to the second beam splitter prism after reflection, and then is reflected by the second beam splitter prism and passes through a mode detection device to obtain an interference pattern of a concentric perfect vortex and a spherical wave.

8. The multi-beam perfect vortex spatial multiplexing generation and pattern detection device according to claim 7, characterized in that: The concentric perfect vortex capture device comprises: a first convex lens and a first CCD camera; The first convex lens is used to perform Fourier transform on the regulated light beam to obtain a concentric perfect vortex, which is captured by the first CCD camera.

9. The multi-beam perfect vortex spatial multiplexing generation and pattern detection device according to claim 7, characterized in that: The mode detection device comprises: a second convex lens and a second CCD camera; The second convex lens is used to transform the received light beam into a concentric perfect vortex and a spherical wave respectively. The two transformed light beams interfere with each other and are captured by the second CCD camera.

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