A method and system for generating a vertical focal field of a space structure

Abstract

The present application relates to the field of information optics, more particularly, to a spatial structure vertical focal field generation method and system. The present application provides a spatial structure vertical focal field generation method, according to the constructed phase map of the spatial structure vertical focal field, the incident light beam is modulated into a cylindrical wave light beam at the light beam modulation, and then the cylindrical wave light beam is focused to generate a spatial structure vertical focal field. Wherein, the phase map only needs to be calculated according to the superposition of the column lens phase or the column lens phase and the flash grid phase, and the calculation amount and calculation time are obviously reduced compared with the iterative calculation of the existing method. The present application solves the problems of large calculation amount and long time consumption of the existing method for generating a spatial structure vertical focal field.

Description

Technical Field

[0001] This invention relates to the field of information optics technology, and more specifically, to a method for generating a vertical focal field of a spatial structure, and a system for generating a vertical focal field of a spatial structure using this method. Background Technology

[0002] Structured light fields achieve a specific intensity distribution within a focused space by manipulating information such as the amplitude, phase, and polarization of incident light. Among them, the vertical focal field of the spatial structure has important application value in fields such as optical tweezers manipulation and laser microfabrication.

[0003] Currently, structured light fields can be generated by designing complex phase patterns and using computational holography to create more complex spatial structured light fields. However, this method has drawbacks: poor Z-axis quality, and the need for iterative algorithms to calculate the three-dimensional spatial light field, which consumes a lot of computation time. Other methods utilize wavefront modulation of the beam to achieve specific light field distributions, such as transversely self-accelerating Airy beams or vortex beams with ring-shaped light field distributions. However, this method can only generate a very limited range of structured light fields, and its structural parameters and spatial range are still restricted.

[0004] In general, there is a lack of a convenient and quick method for generating vertical focal fields of spatial structures to generate adjustable vertical focal fields of spatial structures. Summary of the Invention

[0005] Therefore, it is necessary to provide a method and system for generating vertical focal fields of spatial structures, addressing the problems of large computational load and long time consumption in existing methods for generating vertical focal fields of spatial structures.

[0006] This invention is achieved using the following technical solution:

[0007] In a first aspect, this invention discloses a method for generating a vertical focal field of a spatial structure, used to generate a vertical focal field of a spatial structure. The vertical focal field of the spatial structure includes a primary focus and a secondary focus, with the secondary focus and the primary focus located on two vertical planes in space, respectively.

[0008] The method for generating a vertical focal field for a spatial structure includes the following steps:

[0009] Phase of the vertical focal field of the spatial structure Figure 1 or phase Figure 2 Among them, phase Figure 1 A hologram with the phase of a cylindrical lens loaded; phase Figure 2 A hologram superimposed with the phase of the cylindrical lens and the phase of the grating;

[0010] Using a beam modulator based on phase Figure 1 or phase Figure 2 Modulate the incident beam into a cylindrical wave beam;

[0011] A focusing device is used to focus a cylindrical wave beam, and f is controlled to be ≠ d to generate a vertical focal field of a spatial structure; where f represents the focusing distance of the cylindrical wave beam, and d represents the distance from the beam modulator to the focal point of the cylindrical wave beam.

[0012] This spatial structure vertical focal field generation method implements the method or process according to the embodiments of this disclosure.

[0013] Secondly, the present invention discloses a spatial structure vertical focal field generation system, which uses the spatial structure vertical focal field generation method of the first aspect.

[0014] The spatial structure vertical focal field generation system includes: a beam generator, an energy adjustment module, a beam transmission module, a beam modulator, a focuser, and a monitoring module. The beam generator emits the outgoing laser beam. The energy adjustment module controls the energy of the outgoing laser beam. The beam transmission module adjusts the transmission of the energy-controlled outgoing laser beam to form the incident beam. The beam modulator adjusts the beam according to the phase... Figure 1 or phase Figure 2 The incident beam is modulated into a cylindrical wave beam. A focuser is used to focus the cylindrical wave beam and control f≠d to generate a vertical focal field of the spatial structure. A monitoring module is used to monitor the generated vertical focal field of the spatial structure in real time.

[0015] This spatial structure vertical focal field generation system implements the method or process according to embodiments of this disclosure.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. This invention provides a method for generating a vertical focal field of a spatial structure. Based on the phase diagram of the constructed vertical focal field of the spatial structure, the incident beam is modulated into a cylindrical wave beam at the beam modulation point, and then the cylindrical wave beam is focused to generate the vertical focal field of the spatial structure. The phase diagram only needs to be calculated based on the phase of the cylindrical lens, or the superposition of the phase of the cylindrical lens and the phase of the grating, which significantly reduces the computational load and time compared to the iterative calculations of existing methods.

[0018] 2. The spatial structure vertical focal field generation method provided by the present invention produces a smooth propagation trajectory curve of the spatial structure vertical focal field, which has high beam quality.

[0019] 3. The spatial structure vertical focal field generation method provided by the present invention can flexibly adjust the relative positions of the primary and secondary focal points by controlling parameters, thereby achieving flexible beam morphology adjustment and having great flexibility. Attached Figure Description

[0020] Figure 1A three-dimensional light intensity distribution diagram of the vertical focal field of the spatial structure;

[0021] Figure 2 This is a simplified flowchart of a method for generating a vertical focal field in a spatial structure according to Embodiment 1 of the present invention;

[0022] Figure 3 For the present invention Figure 2 Constructing phase Figure 2 Schematic diagram;

[0023] Figure 4 This is a structural diagram of a spatial structure vertical focal field generation system according to Embodiment 1 of the present invention;

[0024] Figure 5 This is a comparison chart of the correctness verification results in Embodiment 2 of the present invention;

[0025] Figure 6 This is a comparison diagram of the results of modulating the relative position of the vertical focal field of the spatial structure in Embodiment 2 of the present invention;

[0026] Figure 7 This is a comparison diagram showing the results of adjusting the secondary focus of the vertical focal field of the spatial structure in Embodiment 2 of the present invention;

[0027] The attached diagram lists the components represented by each number as follows:

[0028] 1. Beam generator; 2. Half-glass slide; 3. Glan Taylor prism; 4. Beam expander; 5. Mirror 1; 6. Beam modulator; 7. Dichroic mirror; 8. Imaging machine; 9. Imaging objective lens; 10. Mirror 2; 11. Three-dimensional motion platform. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] It should be noted that when a component is said to be "installed on" another component, it can be directly on the other component or it may be in a component that is centered on it. When a component is said to be "set on" another component, it can be directly set on the other component or it may also be in a component that is centered on it. When a component is said to be "fixed to" another component, it can be directly fixed to the other component or it may also be in a component that is centered on it.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0032] Example 1

[0033] Please refer to the following first. Figure 1 This is a three-dimensional light intensity distribution map of the vertical focal field of the spatial structure. For example... Figure 1 As shown, the spatial structure's vertical focal field includes a principal focus and secondary focuses. The principal focus forms a straight propagation trajectory, while the secondary focuses form an arc-shaped propagation trajectory. The principal focus and secondary focuses are located on two perpendicular planes in space: according to... Figure 1 The primary focus is located on the ZX plane, and the secondary focus is located on the YZ plane. Since the ZX plane is perpendicular to the YZ plane, the primary focus and the secondary focus are also perpendicular in spatial structure.

[0034] Embodiment 1 of this invention proposes a method for generating a vertical focal field of a spatial structure, which is used to generate... Figure 1 The spatial structure is perpendicular to the focal field. Please refer to [the document / reference]. Figure 2 Here is a simplified flowchart of a method for generating a vertical focal field of a spatial structure according to Embodiment 1 of the present invention, which includes the following steps:

[0035] Step 1: Construct the phase of the vertical focal field of the spatial structure. Figure 1 or phase Figure 2 .

[0036] This step is fundamental to generating the vertical focal field of the spatial structure, and the constructed phase map is used for subsequent modulation of the incident beam.

[0037] Among them, phase Figure 1 A hologram with the phase of a cylindrical lens applied. Phase. Figure 2 This is a hologram that superimposes the phase of the cylindrical lens and the phase of the grating.

[0038] First, by phase Figure 1 Let's take the construction of [the system] as an example to illustrate:

[0039] There are four possible phase distributions for a cylindrical lens:

[0040] ① ②

[0041] ③ ④

[0042] In this context, ① and ③ correspond to the focusing direction of the cylindrical lens being parallel to the Y-axis; ② and ④ correspond to the focusing direction of the cylindrical lens being parallel to the X-axis. j represents the imaginary part; k represents the wave number, k = 2π / λ; and λ represents the wavelength.

[0043] Therefore, the phase of the cylindrical lens is... Four types.

[0044] Then by phase Figure 2 Let's take the construction of [the system] as an example to illustrate this in detail:

[0045] There are four possible phase distributions for a cylindrical lens:

[0046] ① ②

[0047] ③ ④

[0048] In this context, ① and ③ correspond to the focusing direction of the cylindrical lens being parallel to the Y-axis; ② and ④ correspond to the focusing direction of the cylindrical lens being parallel to the X-axis. j represents the imaginary part; k represents the wave number, k = 2π / λ; and λ represents the wavelength.

[0049] Therefore, the phase of the cylindrical lens is... Four types.

[0050] Similarly, the flash grating phase also has: T represents the blaze period of the strobe grid. Wherein, This indicates that the focuser is located in the X direction of the beam modulator 6; This indicates that the focuser is located in the Y direction of the beam modulator 6.

[0051] It should be noted that phase Figure 1 Phase Figure 2 The specific phase selected depends on the beam modulator 6 and focuser used in subsequent steps.

[0052] Step two, using beam modulator 6 according to phase Figure 1 or phase Figure 2 The incident beam is modulated into a cylindrical wave beam.

[0053] The tuning method of beam modulator 6 varies depending on its specific type. It can be directly loaded through a cylindrical lens optical element or a spatial light modulator, or it can be modulated by a binary mask in a 0-pi modulation manner.

[0054] If the beam modulator 6 can be any of the cylindrical lens optical element, binary diffraction plate, or liquid crystal phase plate, this type of beam modulator 6 will not produce a grating effect, therefore there is no need to introduce a flash grating phase, based on the phase... Figure 1 Modulation is performed.

[0055] If beam modulator 6 uses a digital reflecting micromirror or a spatial light modulator, this type of beam modulator 6 will be subject to the grating effect, resulting in strong diffraction of the zeroth-order beam. Therefore, an additional flash grating phase needs to be added, depending on the phase... Figure 2 Modulation is performed.

[0056] Step 3: Use a focuser to focus the cylindrical wave beam and control f≠d to generate a vertical focal field of the spatial structure.

[0057] Where f represents the focusing distance of the cylindrical wave beam, and d represents the distance from the beam modulator 6 to the focusing point of the cylindrical wave beam.

[0058] A cylindrical wave beam is focused by a focuser, which can generate a spatial structure vertical focal field at the back focal plane of the focuser.

[0059] As noted above: Phase Figure 1 Phase Figure 2 The specific phase selected depends on the beam modulator type 6 and the focuser type used in subsequent steps:

[0060] Specifically,

[0061] (1) When based on phase Figure 1 Modulation is performed; beam modulator 6 is a transmission type; if the focusing direction of the cylindrical lens is parallel to the Y-axis, the phase of the cylindrical lens is... If the focusing direction of the cylindrical lens is parallel to the X-axis, the phase of the cylindrical lens is...

[0062] (2) When based on phase Figure 1 Modulation is performed; beam modulator 6 is a reflective type; if the focusing direction of the cylindrical lens is parallel to the Y-axis, the phase of the cylindrical lens is... If the focusing direction of the cylindrical lens is parallel to the X-axis, the phase of the cylindrical lens is...

[0063] (3) When based on phase Figure 2 Modulation is performed, beam modulator 6 is a transmission type, and the focuser is located in the X direction of beam modulator 6. If the focusing direction of the cylindrical lens is parallel to the Y-axis, the phase of the cylindrical lens is... The phase of the flash grating is If the focusing direction of the cylindrical lens is parallel to the X-axis, the phase of the cylindrical lens is... The phase of the flash grating is

[0064] (4) When based on phase Figure 2 Modulation is performed, with beam modulator 6 being a transmissive type and the focuser located in the Y direction of beam modulator 6; if the focusing direction of the cylindrical lens is parallel to the Y-axis, the phase of the cylindrical lens is... The phase of the flash grating is If the focusing direction of the cylindrical lens is parallel to the X-axis, the phase of the cylindrical lens is... The phase of the flash grating is

[0065] (5) When based on phase Figure 2 Modulation is performed, beam modulator 6 is a reflective type, and the focuser is located in the X direction of beam modulator 6. If the focusing direction of the cylindrical lens is parallel to the Y-axis, the phase of the cylindrical lens is... The phase of the flash grating is If the focusing direction of the cylindrical lens is parallel to the X-axis, the phase of the cylindrical lens is... The phase of the flash grating is

[0066] (6) When based on phase Figure 2 Modulation is performed, beam modulator 6 is a reflective type, and the focuser is located in the Y direction of beam modulator 6. If the focusing direction of the cylindrical lens is parallel to the Y-axis, the phase of the cylindrical lens is... The phase of the flash grating is If the focusing direction of the cylindrical lens is parallel to the X-axis, the phase of the cylindrical lens is... The phase of the flash grating is

[0067] It should also be noted that in step one, the phase is constructed based on the selected phase. Figure 1 or phase Figure 2 The process involves coordinate transformation, specifically converting the phase coordinates (x, y) to the beam modulator coordinates (m, n). See [link / reference] Figure 3 , in (3) Taking an example, if beam modulator 6 is selected as a spatial light modulator (manufactured by HOLOEYEPhotonics AG, model PLUTO2), then converting to the coordinates (m, n) of beam modulator 6 involves encoding the panel of that spatial light modulator. The specific process is as follows:

[0068] First, set the size of the holographic template image to 1080*1080 (unit: pixels), that is, the horizontal dimension is 1080 and the vertical dimension is 1080. Then, use the built-in Matlab function meshgrid to divide the holographic template image into a grid, with the lower left corner of the holographic template image as the starting point and the coordinates as (0, 0); and the upper right corner of the holographic template image as the ending point and the coordinates as (1080, 1080). The center coordinates of the holographic template image are (540.5, 540.5). The coordinates of the grid vertices are (m, n), where m, n∈(0, 1080).

[0069] Next, set the center pixel coordinates of the mask image to (540.5, 540.5), corresponding to the center pixel coordinates of the empty holographic template image. Since the coordinate system of the phase formula is (x,y), while the coordinate system of the holographic template image is (m,n), the conversion relationship between the two coordinate systems is (x,y) = 540.5 - (m,n). Therefore, when the grid vertex coordinates are (m,n) = (0,0), the corresponding (x,y) coordinates are (-540.5, -540.5), and when the grid vertex coordinates are (m,n) = (1080, 1080), the corresponding (x,y) coordinates are (539.5, 539.5).

[0070] Next, phase writing is performed. Starting from any vertex of the holographic template as a reference point, the entire holographic template is filled by scanning the m-direction first, then the n-direction, according to the phase value to be written. Calculate the phase value of the holographic template plane:

[0071]

[0072] Then, the phase value φ(m,n) at any point (m,n) is converted into a grayscale value holo(m,n) and saved as a hologram. The numerical correspondence between holo(m,n) and φ(m,n) is as follows:

[0073]

[0074] See Figure 4 This embodiment 1 also discloses a spatial structure vertical focal field generation system, which uses the above-described spatial structure vertical focal field generation method.

[0075] A spatial structure vertical focal field generation system includes: a beam generator 1, an energy adjustment module, a beam transmission module, a beam modulator 6, a focuser, and a monitoring module.

[0076] Beam generator 1 is used to emit the emitted laser. Generally, beam generator 1 is a laser, which can be a continuous laser or a pulsed laser.

[0077] The energy adjustment module is used to regulate the energy of the emitted laser. The energy adjustment module can use an attenuator to adjust the emitted laser energy based on light absorption, or it can use a polarizer to adjust the emitted laser energy based on a relative angle. In this embodiment 1, the energy adjustment module includes a half-glass slide 2 and a Glan Taylor prism 3. The half-glass slide 2 is used to polarize the emitted laser, and the Glan Taylor prism 3 is used to control the polarization of the emitted laser; the two work together to regulate the energy.

[0078] The beam transmission module is used to adjust the transmission of the energy-controlled emitted laser to form an incident beam. In this embodiment 1, the beam transmission module includes a beam expander 4 and a reflector 5. The beam expander 4 is used to change the diameter and divergence angle of the energy-controlled emitted laser so that the beam diameter matches the size of the beam modulator 6. The reflector 5 is used to change the direction of the beam to form an incident beam on the beam modulator 6.

[0079] Beam modulator 6 is used according to phase Figure 1 or phase Figure 2 The incident beam is modulated into a cylindrical wave beam. Referring to the above, the adjustment method for beam modulator 6 varies depending on its specific type.

[0080] The focuser is used to focus the cylindrical wave beam and control f≠d to generate a vertical focal field of the spatial structure. In this embodiment 1, the focuser includes an imaging objective 9, a second reflecting mirror 10, and a three-dimensional motion platform 11. The cylindrical wave beam diffracts and propagates a certain distance in space before reaching the front focal plane of the imaging objective 9. The imaging objective 9 focuses the cylindrical wave beam, generating a vertical focal field of the spatial structure at the rear focal plane of the imaging objective 9. The imaging objective 9 and the second reflecting mirror 10 are mounted on the three-dimensional motion platform 11, which adjusts the relative distance between the imaging objective 9 (i.e., the focal point of the cylindrical wave beam) and the beam modulator 6. The second reflecting mirror 10 is used to reflect the beam of the vertical focal field of the spatial structure to the monitoring module.

[0081] The monitoring module is used to monitor the vertical focal field of the generated spatial structure in real time. In this embodiment 1, the monitoring module includes a dichroic mirror 7 and an imaging camera 8. The dichroic mirror 7 has two functions: 1. to reflect the cylindrical wave beam to the imaging objective lens 9 for focusing; 2. to reflect the beam reflected back by the mirror 10 back to the imaging camera 8. The imaging camera 8 collects and records the information of the reflected beam. The imaging camera 8 can be a device with light-collecting function, such as a mobile phone, camera, or video camera.

[0082] Example 2

[0083] (1) This embodiment 2 verifies the correctness of the method in embodiment 1:

[0084] Both theoretical calculations and experimental measurements were performed. The theoretical calculations used the Richards-Wolf vector diffraction integral to calculate the beam. The experimental measurements were performed with f set to 1000 mm to calculate the phase. Figure 1 The beam is loaded onto beam modulator 6 and focused using a 100x objective lens with a numerical aperture of 0.85 and a focal length of 1600mm to observe and record the vertical focal field of the resulting spatial structure.

[0085] See results comparison. Figure 5 , Figure 5(a) represents the theoretical light field distribution of the vertical focal field of the spatial structure at different focusing positions. Figure 5 (b) shows the measured optical field distribution at different focusing positions of the vertical focal field of the spatial structure. Here, 0λ, 1λ, 2λ, 3λ, and 4λ represent cross-sections along the Z-axis (i.e., the beam propagation direction from -z to +z) at distances of 0λ, 1λ, 2λ, 3λ, and 4λ, respectively. 0λ represents z = 0; 1λ represents a distance of z = 1λ; 2λ represents z = 2λ; 3λ represents z = 3λ; and 4λ represents z = 4λ. It can be seen that the measured optical field is consistent with the theoretically simulated optical field, demonstrating the correctness of this method.

[0086] (2) In this embodiment 2, the vertical focal field of the spatial structure was also controlled. By changing the values ​​of f and d, the change of the vertical focal field of the spatial structure was examined.

[0087] See Figure 6 , Figure 6 The left side shows the three-dimensional light intensity distribution of the vertical focal field of the spatial structure corresponding to different f and d relationships. The dashed line represents the position of z=0 on the Z-axis; the black arrow indicates the direction of beam propagation. Figure 6 right side and Figure 5 Similarly, it shows the theoretical and measured light field distributions at different focusing positions.

[0088] Depend on Figure 6 As can be seen on the right, the measured light field is consistent with the theoretical simulation result, which also verifies the correctness of this method.

[0089] Depend on Figure 6 From the left side, we can see that if f < d, the principal focus appears first along the direction of beam propagation, followed by the secondary focus; if f = d, the spatial structure perpendicular to the focal field only has the principal focus, with no secondary focus. If f > d, the secondary focus appears first along the direction of beam propagation, followed by the principal focus.

[0090] In addition, the inventors also examined the impact of the difference between f and d. See [link / reference] Figure 7 This shows the cross-section of the vertical focal field of the space structure in the ZX coordinate plane: d is taken as 1600mm, and f gradually increases from 1100mm to 2000mm:

[0091] Figure 7 (A)- Figure 7 (D) shows the process of f gradually increasing from 1100mm to 1600mm, during which the secondary focus is located above the primary focus and gradually moves away from the primary focus; Figure 7 (E) shows the case where f = d = 1600 mm, in which the secondary focus is generated at infinity and only the principal focus exists; Figure 7 (F)- Figure 7(L) shows the process of f continuing to increase towards 2000mm, during which the secondary focus is located below the primary focus and gradually approaches the primary focus.

[0092] In general: the smaller the difference between f and d, the farther the distance between the secondary focus and the primary focus.

[0093] Example 3

[0094] This embodiment also discloses a readable storage medium storing computer program instructions. When the computer program instructions are read and run by a processor, the steps of the spatial structure vertical focal field generation method of Embodiment 1 are executed.

[0095] When applying the method of Example 1, it can be applied in the form of software, such as by designing it as a program that can run independently on a computer-readable storage medium, which can be a USB flash drive. The USB flash drive can be designed as a program that starts the entire method through an external trigger.

[0096] In addition, the inventors submitted color versions of some of the accompanying drawings as additional supporting documentation.

[0097] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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.

[0098] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for generating a vertical focal field of a spatial structure, characterized in that, The spatial structure vertical focal field includes a primary focal point and a secondary focal point, with the secondary focal point and the primary focal point located on two vertical planes in space, respectively. The method for generating a vertical focal field for a spatial structure includes the following steps: Construct either Phase Map 1 or Phase Map 2 of the vertical focal field of the spatial structure; wherein, Phase Map 1 is a hologram loaded with the phase of the cylindrical lens; and Phase Map 2 is a hologram superimposed with the phase of the cylindrical lens and the phase of the flash grating. The incident beam is modulated into a cylindrical wave beam according to the phase diagram one or phase diagram two using a beam modulator. The cylindrical wave beam is focused using a focuser and controlled. f ≠ d This generates a vertical focal field in the spatial structure; among which... f This indicates the focusing distance of the cylindrical wave beam. d This indicates the distance from the beam modulator to the focal point of the cylindrical wave beam.

2. The method for generating a vertical focal field for a spatial structure according to claim 1, characterized in that, like f < d Along the direction of beam propagation, the primary focus appears first, followed by the secondary focus; like f > d The secondary focus appears first along the direction of beam propagation, followed by the primary focus.

3. The method for generating a vertical focal field for a spatial structure according to claim 1, characterized in that, f and d The smaller the difference, the farther the secondary focus is from the primary focus.

4. The method for generating a vertical focal field for a spatial structure according to claim 1, characterized in that, If the beam modulator is any one of a cylindrical lens optical element, a binary diffraction plate, or a liquid crystal phase plate, modulation is performed according to the phase diagram one.

5. The method for generating a vertical focal field for a spatial structure according to claim 1, characterized in that, If the beam modulator is a digital reflective micromirror or a spatial light modulator, modulation is performed according to the second phase diagram.

6. The method for generating a vertical focal field for a spatial structure according to claim 4, characterized in that, When modulation is performed according to the phase diagram described above, the beam modulator is of the transmission type; if the focusing direction of the cylindrical lens is... Y The axes are parallel, and the phase of the cylindrical lens is If the focusing direction of the cylindrical lens is the same as... X The axes are parallel, and the phase of the cylindrical lens is ; in, j Indicates the imaginary part; k Indicates wave number, k =2π / λ ; λ Indicates wavelength; x express X Axis coordinates y express Y Axis coordinates.

7. The method for generating a vertical focal field for a spatial structure according to claim 4, characterized in that, When modulation is performed according to the phase diagram described above, the beam modulator is a reflective type; if the focusing direction of the cylindrical lens is... Y The axes are parallel, and the phase of the cylindrical lens is If the focusing direction of the cylindrical lens is the same as... X The axes are parallel, and the phase of the cylindrical lens is ; in, j Indicates the imaginary part; k Indicates wave number, k =2π / λ ; λ Indicates wavelength; x express X Axis coordinates y express Y Axis coordinates.

8. The method for generating a vertical focal field for a spatial structure according to claim 5, characterized in that, When modulation is performed according to the second phase diagram, the beam modulator is a transmission type and the focuser is located on the beam modulator. X Direction, if the focusing direction of the cylindrical lens is the same as... Y The axes are parallel, and the phase of the cylindrical lens is The phase of the flash grating is If the focusing direction of the cylindrical lens is the same as... X The axes are parallel, and the phase of the cylindrical lens is The phase of the flash grating is ; When modulation is performed according to the second phase diagram, the beam modulator is a transmission type and is a focuser located within the beam modulator. Y Direction; if the focusing direction of the cylindrical lens is the same as... Y The axes are parallel, and the phase of the cylindrical lens is The phase of the flash grating is ; If the focusing direction of the cylindrical lens is... X The axes are parallel, and the phase of the cylindrical lens is The phase of the flash grating is ; in, j Indicates the imaginary part; k Indicates wave number, k =2π / λ ; λ Indicates wavelength; x express X Axis coordinates y express Y Axis coordinates; T This indicates the flashing period of the strobe grid.

9. The method for generating a vertical focal field for a spatial structure according to claim 5, characterized in that, When modulation is performed according to the second phase diagram, the beam modulator is a reflective type and the focuser is located on the beam modulator. X Direction, if the focusing direction of the cylindrical lens is the same as... Y The axes are parallel, and the phase of the cylindrical lens is The phase of the flash grating is ; If the focusing direction of the cylindrical lens is... X The axes are parallel, and the phase of the cylindrical lens is The phase of the flash grating is ; When modulation is performed according to the second phase diagram, the beam modulator is a reflective type and the focuser is located on the beam modulator. Y Direction, if the focusing direction of the cylindrical lens is the same as... Y The axes are parallel, and the phase of the cylindrical lens is The phase of the flash grating is ; If the focusing direction of the cylindrical lens is... X The axes are parallel, and the phase of the cylindrical lens is The phase of the flash grating is ; in, j Indicates the imaginary part; k Indicates wave number, k =2π / λ ; λ Indicates wavelength; x express X Axis coordinates y express Y Axis coordinates; T This indicates the flashing period of the strobe grid.

10. A spatial structure vertical focal field generation system, characterized in that, It uses the spatial structure vertical focal field generation method as described in any one of claims 1-9; The spatial structure vertical focal field generation system includes: A beam generator, used to emit outgoing laser light; An energy regulation module is used to regulate the energy of the emitted laser. A beam transmission module is used to transmit and adjust the energy-modulated outgoing laser to form an incident beam. A beam modulator for modulating an incident beam into a cylindrical wave beam according to phase diagram one or phase diagram two. A focuser, used to focus and control cylindrical wave beams. f ≠ d This generates a vertical focal field in a spatial structure; as well as The monitoring module is used to monitor the vertical focal field of the generated spatial structure in real time.

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