A device and method for generating a multi-spiral beam array by superimposing overlapping diffraction invariant optical vortex arrays

Abstract

The invention discloses a device and method for generating a multi-spiral light beam array by superposing overlapable diffraction invariant optical vortex arrays, comprising: a light source, a beam expanding collimator, which converts the light beam into a large-aperture parallel light beam; a spatial light modulator, which modulates the wavefront of the light field of the light beam; a first Fourier lens, whose rear focal plane is the spectrum of the light field after passing through the spatial light modulator; a filter, which allows the outer quasi-symmetric light spot and the inner quasi-symmetric light spot of the +1-order spectrum to pass; a second Fourier lens, which converts the outer quasi-symmetric light spot into a quasi-symmetric plane wave with the same axial wave vector, and converts the inner quasi-symmetric light spot into a quasi-symmetric plane wave with the same axial wave vector, and the inner or outer plane waves interfere to generate two overlapable diffraction invariant optical vortex arrays with different topological charges; the two overlapable diffraction invariant optical vortex arrays with different topological charges are superimposed to form an array light field with a multi-spiral structure in intensity distribution.

Description

Technical Field

[0001] The invention discloses a device and method for generating a multi-helix array by superimposing overlapping diffraction invariant optical vortex arrays Background Art

[0002] A spatial spiral beam is a beam with a special light intensity distribution in space. Its intensity distribution is distributed in a spiral structure along the optical axis. It has certain application value in the fields of material processing, particle manipulation, particle diversion, and optical communication.

[0003] In the past, the method of generating a spatial spiral beam array by applying an axial plane wave interference to a diffraction invariant vortex array had some problems. Since the topological charge in the diffraction invariant vortex array can only be +1 or -1, each spiral beam unit has only a single spiral, which limits the application of array spatial spiral beams in actual production and life. Summary of the invention

[0004] Based on the basic principle of multi-beam interference, the present invention proposes a device and method for generating a multi-helix beam array by superposition of overlappable diffraction invariant optical vortex arrays.

[0005] The technical solution adopted by the present invention is as follows:

[0006] The present invention proposes a device for generating a multi-helical beam array by superimposing overlappable diffraction invariant optical vortex arrays, comprising:

[0007] light source

[0008] A beam expander collimator is arranged in the direction of light emitted by the light source and is used to convert the light from the light source into a large-diameter parallel beam;

[0009] A spatial light modulator is arranged at the rear end of the beam expansion collimator and is used to modulate the wavefront of the light field of the large-aperture parallel light beam;

[0010] A first Fourier lens is arranged at the rear end of the spatial light modulator, and at its rear focal plane is the spectrum of the light field after passing through the spatial light modulator;

[0011] A filter is placed at the spectrum plane of the light field, allowing the outer quasi-symmetrical light spot and the inner quasi-symmetrical light spot of the +1-order spectrum to pass through at the same time;

[0012] The second Fourier lens is arranged at the rear end of the filter, converts the outer quasi-symmetric light spot into a quasi-symmetric plane wave with the same axial wave vector, and converts the inner quasi-symmetric light spot into a quasi-symmetric plane wave with the same axial wave vector. The quasi-symmetric plane waves corresponding to the inner or outer quasi-symmetric light spots interfere with each other and respectively generate two overlapping diffraction invariant optical vortex arrays. The two diffraction invariant optical vortex arrays are superimposed to form an array light field with a multi-helix structure in intensity distribution in space.

[0013] As a further feature, the light source is a laser light source.

[0014] As a further feature, a CCD is also included. The CCD is placed at the rear end of the second Fourier lens and is used to record the intensity distribution of the multi-helix beam array.

[0015] As a further feature, the spatial light modulator can generate twelve plane waves by applying a grayscale image. The twelve plane waves are divided into two groups, six plane waves each with inner and outer quasi-symmetric beams. The interference of the six quasi-symmetric plane waves on the inner side generates a triangular vortex array with a topological charge of ±1, and the topological charges of adjacent vortices have opposite signs. The interference of the six quasi-symmetric plane waves on the outer side generates a triangular vortex array with a topological charge of ±2, and the topological charges of adjacent vortices have opposite signs.

[0016] Furthermore, the two triangular vortex beam arrays formed by the interference of six quasi-symmetric plane waves corresponding to the six quasi-symmetric light spots on the inner and outer sides have the same period and can be completely overlapped, and the phase change directions of the vortices at the same position are opposite. When the amplitude A1=A2 of the beam, the superposition of these two triangular vortex arrays with different topological charges can produce a triple-helix beam array with the best contrast.

[0017] As a further feature, the spatial light modulator can generate sixteen plane waves by applying a grayscale image. The sixteen plane waves are divided into two groups, eight plane waves each with inner and outer quasi-symmetric beams. The interference of the eight quasi-symmetric plane waves on the inner side generates a square vortex array with a topological charge of ±1, and the topological charges of adjacent vortices have opposite signs. The interference of the eight quasi-symmetric plane waves on the outer side generates a square vortex array with a topological charge of ±3, and the topological charges of adjacent vortices have opposite signs.

[0018] Furthermore, the square vortex beam array formed by the interference of eight quasi-symmetric plane waves corresponding to the eight quasi-symmetric light spots on the inner and outer sides has the same period and can be completely overlapped, and the phase change directions of the vortices at the same position are opposite. When the amplitude A1 of the beam is A2, the superposition of these two square vortex arrays with different topological charges can obtain the four-helix beam array with the best contrast.

[0019] The device disclosed in the present invention for generating a multi-helix beam array by superimposing overlappable diffraction invariant optical vortex arrays is applied in a material processing device for processing materials.

[0020] The invention discloses a device for generating a multi-spiral light beam array by superimposing overlappable diffraction invariant optical vortex arrays, which is applied in a particle manipulation device.

[0021] The device disclosed in the present invention utilizes overlapped diffraction invariant optical vortex arrays to generate a multi-spiral beam array, and its application is extended to ion beams, electron beams, terahertz, X-rays, sound waves, etc.

[0022] The present invention also provides a method for generating a multi-helical beam array, as follows:

[0023] The laser obtains a large-aperture parallel light beam after passing through a beam expander collimator; the wavefront of the light field of the large-aperture parallel light beam is modulated after passing through a spatial light modulator, and the spectrum of the light field is obtained at the rear focal plane of the first Fourier lens after passing through a first Fourier lens, and a filter is placed at the spectrum plane to allow twelve or sixteen light spots in the +1-level spectrum to pass through, and these light spots are divided into two equal inner and outer groups with quasi-symmetrical structures, and the inner or outer quasi-symmetrical light spots will be converted into several quasi-symmetrical plane waves with the same axial wave vector after passing through a second Fourier lens, and these light beams interfere to generate a spatial diffraction-invariant light field along the optical axis, and the phases of several quasi-symmetrical light spots are reasonably adjusted by controlling the grayscale image loaded on the spatial light modulator, and the diffraction-invariant light field can be a vortex beam array.

[0024] Two overlapping diffraction invariant optical vortex arrays with different topological charges generated by the interference of quasi-symmetric plane waves corresponding to the inner and outer quasi-symmetric light spots are superimposed to form a spiral beam array with good contrast in space.

[0025] Technical effects of the present invention:

[0026] The present invention is based on the basic principle of multi-beam interference and adopts a spatial light modulator. The light field is modulated by changing the grayscale image applied to the spatial light modulator, and then twelve (or sixteen) light spots of +1 level spectrum are obtained through a filter. Multi-beam interference is realized by using a relatively simple optical path, and an overlapping optical vortex array with two different topological charges is generated. A multi-spiral beam array is obtained by superposition of the vortex arrays.

[0027] This method can be used to relatively easily obtain multi-helix light beams. This method has not been proposed by anyone yet and has the excellent characteristic of being easy to implement. This method has important application value in the fields of material processing and particle manipulation. This method can also be extended to ion beams, electron beams, terahertz, X-rays, sound waves and other aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The optical path diagram of the embodiment disclosed in the present invention is a schematic diagram.

[0029] Figure 2(a) is a schematic diagram of the interference configuration of twelve plane waves.

[0030] Figure 2(b) is a schematic diagram of the Fourier transverse wave vector components of twelve plane waves.

[0031] Figure 3 (a1) is a schematic diagram of the transverse wave vector components of the inner six plane waves.

[0032] Figure 3 (b1) shows the normalized intensity distribution of the light field formed by the interference of the six inner plane waves.

[0033] Figure 3 (c1) shows the phase distribution of the light field formed by the interference of the six inner plane waves.

[0034] Figure 3 (a2) is a schematic diagram of the transverse wave vector components of the six outer plane waves.

[0035] Figure 3 (b2) shows the normalized intensity distribution of the light field formed by the interference of the six outer plane waves.

[0036] Figure 3 (c2) shows the phase distribution of the light field formed by the interference of the six outer plane waves.

[0037] Figure 4 It is a triple spiral beam array formed by the interference of twelve beams of light in three-dimensional space.

[0038] Figure 5 Schematic diagram of the Fourier transverse wave vector components of sixteen plane waves.

[0039] Figure 6 (a1) is a schematic diagram of the transverse wave vector components of the inner six plane waves.

[0040] Figure 6 (b1) shows the normalized intensity distribution of the light field formed by the interference of the inner eight plane waves.

[0041] Figure 6 (c1) shows the phase distribution of the light field formed by the interference of the eight inner plane waves.

[0042] Figure 6 (a2) is a schematic diagram of the transverse wave vector components of the outer eight plane waves.

[0043] Figure 6 (b2) shows the normalized intensity distribution of the light field formed by the interference of the eight outer plane waves.

[0044] Figure 6 (c2) shows the phase distribution of the light field formed by the interference of the eight outer plane waves.

[0045] Figure 7 A quadruple helix beam array formed by the interference of sixteen light beams in three-dimensional space. DETAILED DESCRIPTION

[0046] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0047] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or their combinations;

[0048] As described in the background technology, the inventors have found that there are some problems with the previous method of generating a spatial spiral beam array by applying a beam of axial plane wave interference to a diffraction invariant optical vortex array. Since the topological charge in the diffraction invariant vortex array can only be +1 or -1, each spiral beam unit has only a single spiral, which limits the application of the array spatial spiral beam in actual production and life. In order to solve the above technical problems, the present application proposes a device and method for generating a multi-spiral beam array by superimposing overlappable diffraction invariant optical vortex arrays. Example 1

[0049] In a typical embodiment of the present application, the optical path diagram of the present invention is as follows Figure 1 shown. Figure 1 In it, there are laser light source 1, beam expander collimator 2, spatial light modulator 3, first Fourier lens 4, filter 5, second Fourier lens 6, and CCD 7.

[0050] The laser light source 1 adopts an existing laser light source;

[0051] A beam expander collimator 2, arranged in the direction of light emitted by the light source, for converting the light from the light source into a large-diameter parallel beam;

[0052] The spatial light modulator 3 is arranged at the rear end of the beam expansion collimator 2 and is used to modulate the wavefront of the light field of the large-aperture parallel light beam;

[0053] The first Fourier lens 4 is arranged at the rear end of the spatial light modulator 3, and the spectrum of the light field after passing through the spatial light modulator 3 is at its rear focal plane;

[0054] Filter 5, which is placed at the spectrum plane of the light field and allows the outer quasi-symmetrical light spot and the inner quasi-symmetrical light spot in the +1-order spectrum to pass;

[0055] The second Fourier lens 6 is arranged at the rear end of the filter 5 to convert the outer quasi-symmetrical light spot into a quasi-symmetrical

[0056] A plane wave with the same axial wave vector converts the inner quasi-symmetric light spot into a plane wave with the same axial wave vector. The two overlapping diffraction invariant optical vortex arrays with different topological charges generated by the interference of the quasi-symmetric plane waves corresponding to the inner and outer quasi-symmetric light spots are superimposed to form an array light field with a multi-helix structure in intensity distribution in space.

[0057] As a further feature, a CCD 7 is also included. The CCD 7 is placed at the rear end of the second Fourier lens 6 and is used to record the intensity distribution of the multi-helix array.

[0058] As a further feature, the spatial light modulator can generate twelve plane waves by applying a grayscale image. The six plane wave interferences corresponding to the six quasi-symmetrical light spots on the inner side generate a triangular vortex array with a topological charge of ±1, and the topological charges of adjacent vortices have opposite signs. The six plane wave interferences corresponding to the six quasi-symmetrical light spots on the outer side generate a triangular vortex array with a topological charge of ±2, and the topological charges of adjacent vortices have opposite signs.

[0059] Furthermore, the two diffraction invariant vortex beam arrays generated by the interference of six quasi-symmetric plane waves corresponding to the six quasi-symmetric light spots on the inner and outer sides have the same period and can be completely overlapped, and the phase change directions of the vortices at the same position are opposite. When the amplitude A1 of the light beam is A2, the superposition of these two triangular optical vortex arrays with different topological charges can produce a triple-helix beam array with the best contrast.

[0060] The specific method is:

[0061] The laser obtains a large-aperture parallel light beam after passing through a beam expander collimator; the wavefront of the light field of the large-aperture parallel light beam is modulated after passing through a spatial light modulator, and the spectrum of the light field is obtained at the rear focal plane of the first Fourier lens after passing through the first Fourier lens. A filter is placed at the spectrum plane to allow twelve or sixteen light spots in the +1-level spectrum to pass through, and these light spots can be divided into two equal inner and outer groups, each group is quasi-symmetrical, and each group of quasi-symmetrical light spots will be converted into several quasi-symmetrical plane waves with the same axial wave vector after passing through the second Fourier lens. These light beams interfere and will generate a spatial diffraction-invariant light field along the optical axis. The phases of several quasi-symmetrical light spots are reasonably adjusted by changing the grayscale image applied to the spatial light modulator. The diffraction-invariant light field can be a vortex beam array.

[0062] After obtaining the vortex beam array, two diffraction invariant vortex beam arrays generated by the quasi-symmetric plane wave interference corresponding to the inner and outer quasi-symmetric spots are superimposed to form a multi-helix beam array with good contrast in space.

[0063] Figure 2 (a) is a schematic diagram of the interference configuration of twelve plane waves. Figure 2 (b) is a schematic diagram of the Fourier transverse wave vector components of the twelve plane waves. The twelve beams of light can be divided into two large groups with equal numbers of beams inside and outside, namely, quasi-symmetric plane waves on the outside and quasi-symmetric plane waves on the inside. Assuming that the plane waves in each large group have the same amplitude, the complex amplitudes of each plane wave on the outside and inside are A1 and A2, respectively. The transverse wave vectors of the quasi-symmetric plane waves on the outside and inside are kr1 and kr2, respectively. The quasi-symmetric plane waves on the outside or inside can be further divided into two small groups that are mirror-distributed relative to the xoz plane. The plane waves in each group are uniformly distributed relative to the optical axis. In Figure 2 (b), , , .

[0064] Figure 3 shows the simulation results of the formation of a triangular vortex array with topological charges of ±1 and ±2 by the interference of six quasi-symmetric plane waves. Figure 3 (a1) is a schematic diagram of the transverse Fourier components of the inner six-beam plane wave. , 0 and π in the figure represent the relative initial phase values ​​of the six beams of light. Figure 3 (b1) is the normalized intensity distribution of the light field formed by the interference of the inner six plane waves. Figure 3 (c1) is the phase distribution of the light field formed by the interference of the inner six plane waves. From the results of Figures 3 (b1) and (c1), it can be seen that the quasi-symmetric interference of the six beams of light produces a triangular vortex array with a topological charge of ±1, and the topological charges of adjacent vortices have opposite signs. Figure 3 (a2) is a schematic diagram of the transverse Fourier components of the outer six plane waves, with an angle of , 0 and π in the figure represent the relative initial phase values ​​of the six beams of light. Figure 3 (b2) shows the normalized intensity distribution of the light field formed by the interference of the outer six plane waves. Figure 3 (c2) shows the phase distribution of the light field formed by the interference of the outer six plane waves. From the results of Figures 3 (b2) and (c2), it can be seen that the quasi-symmetric six-beam plane wave interference produces a triangular vortex array with a topological charge of ±2, and the topological charges of adjacent vortices have opposite signs. Upon careful observation, it is found that the vortex beam arrays formed by the interference of the inner and outer six plane waves have the same period and can be completely overlapped, and the phase change directions of the vortices at the same position are opposite. When the amplitude of the beam A1=A2, the superposition of these two triangular vortex arrays with different topological charges can produce a triple spiral beam array with the best contrast.

[0065] Figure 4 The intensity distribution of the triangular vortex array with topological charges of ±1 and ±2 formed by the interference of the six inner and outer plane waves in three-dimensional space. At this time, a triple-helix array light field is obtained. The adjacent spiral units have opposite rotation directions, and the outer layer of each spiral corresponds to 40% of the maximum intensity of the spiral. Example 2

[0066] The optical path of this embodiment is the same as that of Embodiment 1, except that the spatial light modulator used in this embodiment is used to generate an orthogonally arranged square quad-helix light beam array. The specific differences are as follows:

[0067] The spatial light modulator can generate sixteen plane waves by applying a grayscale image. The interference of the eight quasi-symmetric plane waves on the inner side generates a square vortex array with a topological charge of ±1, and the topological charges of adjacent vortices have opposite signs. The interference of the eight quasi-symmetric plane waves on the outer side generates a square vortex array with a topological charge of ±3, and the topological charges of adjacent vortices have opposite signs. The two diffraction invariant vortex beam arrays generated by the interference of eight quasi-symmetric plane waves corresponding to eight quasi-symmetric light spots on the inner and outer sides have the same period and can be completely overlapped. The phase change direction of the vortex at the same position is opposite. When the amplitude A1 of the beam is A2, the superposition of these two square vortex arrays with different topological charges can obtain a four-helix beam array with the best contrast.

[0068] Figure 5 Schematic diagram of the Fourier transverse wave vector components of sixteen plane waves. Figure 5 middle , , Figure 6 shows the simulation results of eight quasi-symmetric plane wave interferences to form a square vortex array with topological charges of ±1 and ±3. Figure 6 (a1) is a schematic diagram of the transverse wave vector components of the six inner plane waves. , 0, π / 2, π, 3π / 2 in the figure represent the relative initial phase values ​​of the eight beams of light. Figure 6 (b1) is the normalized intensity distribution of the light field formed by the interference of the inner eight plane waves. Figure 6 (c1) is the phase distribution of the light field formed by the interference of the inner eight plane waves. From the results of Figures 6 (b1) and (c1), it can be seen that the quasi-symmetric interference of the eight plane waves produces a square vortex array with a topological charge of ±1, and the topological charges of adjacent vortices have opposite signs. Figure 6 (a2) is a schematic diagram of the transverse wave vector components of the outer eight plane waves, and the angle , 0, π / 2, π, 3π / 2 in the figure represent the relative initial phase values ​​of the eight plane waves. Figure 6 (b2) shows the normalized intensity distribution of the light field formed by the interference of the outer eight plane waves. Figure 6 (c2) shows the phase distribution of the light field formed by the interference of the outer eight plane waves. It can be seen from the results of Figures 6 (b2) and (c2) that the quasi-symmetric interference of the eight plane waves produces a square vortex array with a topological charge of ±3, and the topological charges of adjacent vortices have opposite signs. The two vortex beam arrays formed by the interference of the inner and outer eight plane waves have the same period and can be completely overlapped, and the phase change directions of the vortices at the same position are opposite. When the amplitude of the beam A1=A2, the superposition of these two square vortex arrays with different topological charges can obtain the four-helix beam array with the best contrast.

[0069] Figure 7 The intensity distribution of a square vortex array with topological charges of ±1 and ±3 formed by the interference of eight plane waves on the inner and outer sides after interference in three-dimensional space. At this time, a four-helix beam array is obtained. Adjacent spiral units have opposite rotation directions, and the outer layer of each spiral corresponds to 40% of the maximum intensity of the spiral.

[0070] The device and method disclosed in this embodiment for generating a multi-helical beam array by superposition of overlappable diffraction invariant optical vortex arrays can have important application value in the fields of material processing, particle manipulation, etc. This method can also be implemented by using a reflective liquid crystal spatial light modulator or other types of diffraction optical elements. This method can also be extended to ion beams, electron beams, terahertz, X-rays, sound waves, etc.

[0071] The above is only a preferred implementation case of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A device for generating a multi-helical beam array by superimposing overlapping diffraction invariant optical vortex arrays, characterized in that: include: light source; A beam expander collimator is arranged in the direction of light emitted by the light source and is used to convert the light from the light source into a large-diameter parallel beam; A spatial light modulator is arranged at the rear end of the beam expansion collimator and is used to modulate the wavefront of the light field of the large-aperture parallel light beam; A first Fourier lens is arranged at the rear end of the spatial light modulator, and the spatial spectrum of the light field is at the rear focal plane of the first Fourier lens; A filter, which is placed at the spatial spectrum plane of the light field, allows twelve or sixteen light spots of the +1 order spectrum to pass, and these light spots are divided into two groups with the same number, namely, outer quasi-symmetric light spots and inner quasi-symmetric light spots; The second Fourier lens is arranged at the rear end of the filter, and converts the outer quasi-symmetric light spot into a quasi-symmetric outer plane wave with the same axial wave vector, and converts the inner quasi-symmetric light spot into a quasi-symmetric inner plane wave with the same axial wave vector. The inner or outer quasi-symmetric plane waves interfere to respectively generate two overlapping diffraction invariant optical vortex arrays with different topological charges; the two vortex beam arrays have the same period, and the phase change directions of the vortices at the same position are opposite. The two overlapping diffraction invariant optical vortex arrays with different topological charges are superimposed to form an array light field with a multi-helix structure in intensity distribution in space.

2. The device for generating a multi-helical beam array by superimposing overlappable diffraction invariant optical vortex arrays as claimed in claim 1, characterized in that: The light source is a laser light source.

3. The device for generating a multi-helical beam array by superimposing overlappable diffraction invariant optical vortex arrays as claimed in claim 1, characterized in that: It also includes a CCD, which is placed at the rear end of the second Fourier lens and is used to record the intensity distribution of the multi-helix array.

4. The device for generating a multi-helical beam array by superimposing overlappable diffraction invariant optical vortex arrays as claimed in claim 1, characterized in that: The spatial light modulator generates twelve plane waves by applying a grayscale image. The six quasi-symmetrical plane waves on the inner side interfere to generate a triangular vortex array with a topological charge of ±1, and the topological charges of adjacent vortices have opposite signs. The six quasi-symmetrical plane waves on the outer side interfere to generate a triangular vortex array with a topological charge of ±2, and the topological charges of adjacent vortices have opposite signs.

5. The device for generating a multi-helical beam array by superimposing overlappable diffraction invariant optical vortex arrays as claimed in claim 1, characterized in that: The amplitudes of the six inner and outer plane waves are A1 and A2 respectively, where A1=A2.

6. The device for generating a multi-helical beam array by superimposing overlappable diffraction invariant optical vortex arrays as claimed in claim 1, characterized in that: The spatial light modulator generates sixteen plane waves by applying a grayscale image. The eight quasi-symmetrical plane waves on the inner side interfere to generate a square vortex array with a topological charge of ±1, and the topological charges of adjacent vortices have opposite signs. The eight quasi-symmetrical plane waves on the outer side interfere to generate a square vortex array with a topological charge of ±3, and the topological charges of adjacent vortices have opposite signs.

7. The device for generating a multi-helical beam array by superimposing overlappable diffraction invariant optical vortex arrays as claimed in claim 1, characterized in that: The amplitudes of the eight inner and outer plane waves are A1 and A2 respectively, where A1=A2.

8. The device for generating a multi-helical beam array by superimposing overlappable diffraction invariant optical vortex arrays as claimed in claim 1, characterized in that: Used in material processing equipment for material processing.

9. The device for generating a multi-helical beam array by superimposing overlappable diffraction invariant optical vortex arrays as claimed in claim 1, characterized in that: Used in particle manipulation devices.

10. The device for generating a multi-helical beam array by superimposing overlappable diffraction invariant optical vortex arrays as claimed in claim 1, characterized in that: Applications have expanded to ion beams, electron beams, terahertz, X-rays, sound waves, etc.

11. A method for generating a spatial spiral beam array by using the device for generating a multi-spiral beam array by superimposing overlappable diffraction invariant optical vortex arrays as described in any one of claims 1 to 7, characterized in that: include: The laser obtains a large-aperture parallel beam after passing through a beam expander collimator; after the large-aperture parallel beam passes through a spatial light modulator, the wavefront of the light field is modulated, and after passing through a first Fourier lens, the spectrum of the light field is obtained at the rear focal plane of the first Fourier lens, and a filter is placed at the spectrum plane to allow twelve light spots of the +1-order spectrum to pass through, and these light spots are divided into two groups with the same number, namely, outer quasi-symmetric light spots and inner quasi-symmetric light spots; after the six quasi-symmetric light spots on the inner and outer sides pass through a second Fourier lens, they are converted into two groups of six quasi-symmetric plane waves with transverse wave vectors kr1 and kr2 respectively, each group of plane waves has the same axial wave vector, and each group of plane waves interferes, which will generate a spatial diffraction-invariant light field along the optical axis direction, and the phases and relative positions of the six quasi-symmetric light spots are reasonably adjusted by controlling the grayscale image loaded on the spatial light modulator, and the diffraction-invariant light field is a vortex beam array; After obtaining two vortex beam arrays respectively by interfering the inner and outer quasi-symmetric plane waves, the two vortex beam arrays are superimposed to form a spiral beam array in space; or the laser is passed through a beam expander collimator to obtain a large-aperture parallel beam; after the large-aperture parallel beam passes through the spatial light modulator, the wavefront of the light field is modulated, and after passing through the first Fourier lens, the spectrum of the light field is obtained at the rear focal plane of the first Fourier lens, and a filter is placed at the spectrum surface to allow sixteen light spots of the +1 order spectrum to pass through, and these light spots are divided into two groups with the same number, namely, outer quasi-symmetric light spots and inner quasi-symmetric light spots; after the eight quasi-symmetric light spots on the inner and outer sides pass through the second Fourier lens, they are converted into two groups of eight quasi-symmetric plane waves with transverse wave vectors kr1 and kr2 respectively, each group of plane waves has the same axial wave vector, and each group of plane waves interferes, which will generate a spatial diffraction-invariant light field along the optical axis direction, and the phases and relative positions of the eight quasi-symmetric light spots are reasonably adjusted by controlling the grayscale image loaded on the spatial light modulator, and the diffraction-invariant light field is a vortex beam array; After obtaining two vortex beam arrays respectively through the interference of the inner and outer quasi-symmetric plane waves, the two vortex beam arrays are superimposed to form a spiral beam array in space.

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