Scalar vortex beam generation system and method for coaxial conventional or polarized holography

Abstract

This invention relates to a system and method for generating a scalar vortex beam in coaxial conventional or polarized holography. The system includes: a laser source; a polarization beam splitter for splitting the laser beam generated by the laser source into a reference beam and a signal beam; an adjustment system and a first aperture sequentially arranged on the signal beam path, the adjustment system including a first half-wave plate, a quarter-wave plate, a first polarizer, a fan-shaped slit, a first steering device, and a second steering device; a first reflecting mirror, a circular baffle plate attached to the first reflecting mirror, a second half-wave plate, and a second polarizer sequentially arranged on the reference beam path; a beam splitter prism; a first lens for converging the beam after convergence by the beam splitter prism; and holographic recording material, located at the focal point of the first lens, for interfering with and recording the beam converged by the first lens. The components used are simple and low-cost, and the manufacturing process for generating a coaxial conventional scalar vortex beam or a polarized holographic scalar vortex beam is simple.

Description

Technical Field

[0001] This invention relates to the fields of traditional holography, polarized holography, and the generation of special light fields, specifically to a system and method for generating scalar vortex beams based on coaxial traditional holography and based on coaxial polarized holography. Background Technology

[0002] Various methods exist for obtaining scalar vortex beams. Early methods used mode conversion to generate scalar vortex beams, but these required high-order Hermite-Gaussian modes and complex optical systems. Later research revealed that phase modulation could be achieved through spatial variations in thickness or refractive index, using spiral phase plates with helical phase delays. However, fabricating such elements is technically demanding and expensive. Subsequently, Soskin proposed the concept of fork gratings, and holographic optical elements similar to fork gratings and spiral zone plates can also be used to generate optical vortices. However, like spiral phase plates, these elements can only generate vortex beams with specific topological charges. Due to the high cost of the underlying components, fabricating devices with different parameters inevitably leads to cost accumulation. Conversely, digital devices such as spatial light modulators are more attractive, as they can freely manipulate the amplitude and phase of the light field, thereby generating beams with helical phases. In recent years, metasurface materials have also become a hot research area, which can also be used to design and generate beams with helical phases, but their fabrication technology is complex, difficult, and expensive. Summary of the Invention

[0003] In view of the above problems, this application provides a scalar vortex beam generation system and method for coaxial conventional or polarized holography, which solves the problems of complexity, high difficulty and high cost of existing manufacturing technology for generating beams with helical phase.

[0004] To achieve the above objectives, the inventors provide a scalar vortex beam generation system for coaxial conventional or polarized holography, comprising:

[0005] A laser source, used to generate laser light;

[0006] A polarization beam splitter, used to split the laser light generated by a laser source into a reference beam and a signal beam;

[0007] Reference optical path, the reference optical path being used to transmit the reference light;

[0008] A signal optical path, wherein the signal optical path is used to transmit the signal light;

[0009] An adjustment system and a first aperture are sequentially arranged on the signal optical path. The adjustment system is arranged on the signal optical path and includes a first half-wave plate, a quarter-wave plate, a first polarizer, a fan-shaped slit, a first steering device, and a second steering device. The first half-wave plate, the quarter-wave plate, the first polarizer, and the fan-shaped slit are arranged sequentially. The first steering device is used to rotate the first half-wave plate, and the second steering device is used to rotate the fan-shaped slit.

[0010] The reference optical path is provided with a first reflecting mirror, a circular shield attached to the first reflecting mirror, a second half-wave plate and a second polarizer in sequence.

[0011] A beam splitter prism is used to combine the reference light transmitted by the reference optical path and the signal optical path.

[0012] The first lens is used to converge the beam of light after it has been combined by the beam splitter.

[0013] A holographic recording material is disposed at the focal position of a first lens, and the holographic recording material is used to interfere with and record the light beam converged by the first lens.

[0014] In some embodiments, a beam expander system is further included, which is disposed between the laser source and the polarization beam splitter.

[0015] In some embodiments, the beam expander system includes a spatial filter and a second lens.

[0016] In some embodiments, the opening angle of the fan-shaped slit is 0°-5°.

[0017] In some embodiments, the holographic recording material is a polarization-sensitive material PQ / PMMA.

[0018] In some embodiments, an image acquisition unit is also included;

[0019] The image acquisition unit is used to capture images of the scalar vortex beam reproduced by the holographic recording material, and the image acquisition unit includes a third lens and a camera.

[0020] In some embodiments, the image acquisition unit further includes a second aperture, which is disposed between the third lens and the camera.

[0021] In some embodiments, the fan-shaped slit is made of coated aluminum alloy.

[0022] Another technical solution is also provided: a method for generating a scalar vortex beam in coaxial conventional or polarized holography, applied to the aforementioned scalar vortex beam generation system in coaxial conventional or polarized holography, comprising the following steps:

[0023] Laser light sources generate laser light;

[0024] A polarization beam splitter splits the laser beam generated by a laser source into a reference beam and a signal beam.

[0025] The reference optical path delivers the reference light to the beam splitter;

[0026] The signal optical path delivers the signal light to the beam splitter prism;

[0027] The circular shield on the first reflecting mirror blocks the reference light in the reference light path, forming a ring-shaped reference light;

[0028] The adjustment system adjusts the rotational speed ratio between the first half-wave plate and the fan-shaped slit through the first steering device and the second steering device, and adjusts the phase and polarization state of the signal light in conjunction with the quarter-wave plate and the first polarizer for control.

[0029] The first aperture limits the signal light after it has been regulated by the regulation system;

[0030] The incident reference light and signal light are combined using a beam splitter prism.

[0031] The combined beam is focused by the first lens and then sent to the holographic recording material for interference recording.

[0032] In some embodiments, the following steps are also included:

[0033] The image acquisition unit captures the image of the scalar vortex beam reproduced by the holographic recording material.

[0034] Unlike existing technologies, the above technical solution uses a laser source to generate a light source. A polarization beam splitter splits the laser beam generated by the laser source into a signal beam and a reference beam. The signal beam is transmitted through the signal beam path, and the reference beam is transmitted through the reference beam path. After the phase and polarization state of the signal beam are adjusted by the adjustment system on the signal beam path, it is sent to the beam splitter prism through the first aperture. The reference beam is blocked by a circular shield on the first mirror on the reference beam path, forming a ring reference beam that is sent to the beam splitter prism. The beam splitter combines the incoming signal beam and reference beam. The shielding by the circular shield ensures that the reference beam is in the outer ring of the combined beam, while the restriction by the first aperture ensures that the signal beam is in the inner ring of the combined beam. The combined beam is then converged by the first lens and interfered with and recorded by the holographic recording material, thereby generating a coaxial conventional scalar vortex beam or a scalar vortex beam of polarized holography. The components used are simple and low-cost, and the manufacturing process for generating coaxial traditional scalar vortex beams or polarized holographic scalar vortex beams is simple, solving the problems of complex processing and high preparation costs in existing methods.

[0035] The above description of the invention is merely an overview of the technical solution of this application. In order to enable those skilled in the art to better understand the technical solution of this application and to implement it based on the description and drawings, and to make the above-mentioned objectives and other objectives, features and advantages of this application easier to understand, the following description is provided in conjunction with the specific embodiments and drawings of this application. Attached Figure Description

[0036] The accompanying drawings are only used to illustrate the principles, implementation methods, applications, features, and effects of specific embodiments of this application and other related content, and should not be considered as limitations on this application.

[0037] In the accompanying drawings of the instruction manual:

[0038] Figure 1 A schematic diagram of a scalar vortex beam generation system for coaxial conventional or polarized holography as described in a specific embodiment;

[0039] Figure 2 This is a schematic diagram of another structure of the scalar vortex beam generation system for the coaxial conventional or polarized holography described in the specific implementation.

[0040] Figure 3 This is a schematic diagram of another structure of the scalar vortex beam generation system for coaxial conventional or polarized holography described in the specific implementation.

[0041] Figure 4 This is a schematic diagram of another structure of the scalar vortex beam generation system for coaxial conventional or polarized holography described in the specific implementation.

[0042] Figure 5 This is a schematic diagram of a process for generating a scalar vortex beam using a coaxial conventional or polarized holographic technique as described in a specific implementation.

[0043] The reference numerals used in the above figures are explained as follows:

[0044] 1. Laser source, 2. Polarizing beam splitter, 3. First aperture, 4. First half-wave plate, 5. Quarter-wave plate, 6. First polarizer, 7. Slit, 8. First mirror, 9. Second half-wave plate, 10. Second polarizer, 11. Beam splitter, 12. First lens, 13. Holographic recording material, 14. Spatial filter, 15. Second lens, 16. Third lens, 17. Camera, 18. Second aperture. Detailed Implementation

[0045] To illustrate the possible application scenarios, technical principles, implementable specific solutions, and achievable objectives and effects of this application in detail, the following description, in conjunction with the listed specific embodiments and accompanying drawings, provides a detailed explanation. The embodiments described herein are merely illustrative of the technical solutions of this application and are therefore intended to limit the scope of protection of this application.

[0046] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0047] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit this application.

[0048] In the description of this application, the term "and / or" is used to describe the logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and A and B exist simultaneously. Additionally, the character " / " in this document generally indicates that the preceding and following objects have an "or" logical relationship.

[0049] In this application, terms such as “first” and “second” are used only to distinguish one entity or operation from another, and do not necessarily require or imply any actual quantity, hierarchy or order relationship between these entities or operations.

[0050] Unless otherwise specified, the use of terms such as “comprising,” “including,” “having,” or other similar expressions in this application is intended to cover non-exclusive inclusion, which does not exclude the presence of additional elements in a process, method, or product that includes the stated elements, such that a process, method, or product that includes a list of elements may include not only those defined elements but also other elements not expressly listed, or elements inherent to such a process, method, or product.

[0051] Similar to the understanding in the Examination Guidelines, in this application, expressions such as "greater than," "less than," and "exceeding" are understood to exclude the stated number; expressions such as "above," "below," and "within" are understood to include the stated number. Furthermore, in the description of the embodiments in this application, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times," unless otherwise explicitly specified.

[0052] In the description of the embodiments of this application, the space-related expressions used, such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiments or drawings. They are only for the purpose of describing the specific embodiments of this application or for the reader's understanding, and do not indicate or imply that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0053] Unless otherwise expressly specified or limited, the terms "installation," "connection," "linking," "fixing," and "setting," as used in the description of the embodiments of this application, should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two components or the interaction between two components. For those skilled in the art to which this application pertains, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0054] Please see Figure 1 This embodiment provides a scalar vortex beam generation system for coaxial conventional or polarized holography, comprising:

[0055] Laser source 1, the laser source 1 being used to generate laser light;

[0056] Polarization beam splitter 2, which is used to split the laser generated by the laser source 1 into reference light and signal light;

[0057] Reference optical path, the reference optical path being used to transmit the reference light;

[0058] A signal optical path, wherein the signal optical path is used to transmit the signal light;

[0059] An adjustment system and a first aperture 3 are sequentially arranged on the signal optical path. The adjustment system is arranged on the signal optical path and includes a first half-wave plate 4, a quarter-wave plate 5, a first polarizer 6, a fan-shaped slit 7, a first steering device, and a second steering device. The first half-wave plate 4, the quarter-wave plate 5, the first polarizer 6, and the fan-shaped slit 7 are arranged sequentially. The first steering device is used to rotate the first half-wave plate 4, and the second steering device is used to rotate the fan-shaped slit 7.

[0060] The reference optical path is provided with a first reflector 8, a circular baffle plate attached to the first reflector 8, a second half-wave plate 9, and a second polarizer 10 in sequence; wherein, the proportion of the circular baffle plate to the first reflector 8 is such that the cross-sectional area ratio of the signal light to the reference light is 1:1, and the cross-sectional area of ​​the reference light can be slightly larger than that of the signal light.

[0061] Beam splitter 11, the beam splitter 11 is used to combine the reference light transmitted by the reference optical path and the signal optical path.

[0062] The first lens 12 is used to converge the beam of light after it has been focused by the beam splitter 11.

[0063] A holographic recording material 13 is disposed at the focal point of the first lens 12. The holographic recording material 13 is used to interfere with and record the beam converged by the first lens 12. The holographic recording material 13 is a polarization-sensitive material PQ / PMMA, which is made of phenanthrenequinone (PQ), 2,2-azobisisobutyronitrile (AIBN), and methyl methacrylate (MMA). Because the polarization-sensitive PQ / PMMA material has a simple manufacturing process and low cost, optical devices made using this material can solve the problems of complex processing and high manufacturing costs associated with previous methods. Due to its responsive characteristics, the manufacturing time can also be significantly shortened.

[0064] A laser source 1 generates a light source, and a polarization beam splitter 2 splits the laser beam generated by the laser source 1 into a signal beam and a reference beam. The signal beam is transmitted through the signal beam path, and the reference beam is transmitted through the reference beam path. After the phase and polarization state of the signal beam are adjusted by the adjustment system on the signal beam path, it is sent to the beam splitter prism 11 through the first aperture 3. The reference beam is blocked by a circular shield on the first reflector 8 on the reference beam path to form a ring reference beam, which is then sent to the beam splitter prism 11. The beam splitter prism 11 combines the incoming signal beam and reference beam. The shielding by the circular shield ensures that the reference beam is in the outer ring of the combined beam, while the restriction by the first aperture 3 ensures that the signal beam is in the inner ring of the combined beam. The combined beam is then converged by the first lens 12 and interfered with and recorded by the holographic recording material 13, thereby generating a coaxial conventional scalar vortex beam or a scalar vortex beam of polarized holography. The components used are simple and low-cost, and the manufacturing process for generating coaxial traditional scalar vortex beams or polarized holographic scalar vortex beams is simple, solving the problems of complex processing and high preparation costs in existing methods.

[0065] By adjusting the system, scalar vortex beams of different orders can be obtained. When preparing a first-order scalar vortex beam, it is only necessary to set the rotational speed ratio of the first half-wave plate 4 and the fan-shaped slit 7 to 1:2. The sign of the rotational speed indicates the direction of rotation: a positive sign indicates counterclockwise, and a negative sign indicates clockwise. For example, when preparing a first-order scalar vortex beam, the rotational speed ratio of the first half-wave plate 4 and the fan-shaped slit 7 is set to 1:2, while when preparing a -3 order scalar vortex beam, the rotational speed ratio of the first half-wave plate 4 and the fan-shaped slit 7 is set to -3:2.

[0066] The difference between methods for generating scalar vortex beams based on conventional coaxial holography and polarized holography lies in the different polarization states of the two coherent lights used in the interference recording. In conventional coaxial holography, the two coherent lights have the same polarization state (i.e., the reference light and signal light have the same polarization state), both linearly polarized in a specific vibration direction. In contrast, in polarized holography, the two coherent lights have orthogonal polarization states (i.e., the reference light and signal light have orthogonal polarization states), for example, linearly polarized light at 45° and -45° directions respectively. The usage of the scalar vortex beam devices and the beam diffraction efficiency also differ between these two methods. The former requires illumination with specific linearly polarized light to generate a scalar vortex beam, but its generated beam has higher diffraction efficiency. The latter can generate a scalar vortex beam using any polarized light, and the polarization state of the resulting beam is related to the polarization state of the illuminating light. For example, when recording signal light and reference light with polarization states of 45° and -45° respectively, their polarization state relationship is only that their rotation directions are opposite. However, the diffraction efficiency of the generated beam is not as high as that of the former.

[0067] Please see Figure 2 In some embodiments, a beam expanding system is further included, which is disposed between the laser source 1 and the polarization beam splitter 2. The beam expanding system is used to expand the laser beam generated by the laser source 1, and includes a spatial filter 14 and a second lens 15. The second lens 15 collimates and expands the laser beam generated by the laser source 1. The spatial filter 14 is disposed between the second lens 15 and the laser source 1, and is used to filter the laser beam generated by the laser source 1, removing wavefront distortions caused by dust or reflective surfaces adhering to the laser source 1.

[0068] In some embodiments, the opening angle α of the fan-shaped slit 7 is in the range of 5° ≥ α > 0°. The smaller the opening angle of the fan-shaped slit 7, the smoother the phase change of the resulting scalar vortex beam, and the smoother the phase change on the phase surface of the resulting scalar vortex beam, the higher the accuracy.

[0069] Please see Figure 3-4 In some embodiments, an image acquisition unit is also included;

[0070] The image acquisition unit is used to capture the image of the scalar vortex beam reproduced by the holographic recording material 13. The image acquisition unit includes a third lens 16 and a camera 17.

[0071] An image acquisition unit consisting of camera 17 and third lens 16 can capture the image of the scalar vortex beam reproduced by the holographic recording material 13, wherein camera 17 can be a CCD camera. The image acquisition unit also includes a second aperture 18, which is positioned between the third lens 16 and camera 17. The reproduced scalar vortex beam is constrained by the third aperture before being captured by camera 17.

[0072] In some embodiments, the fan-shaped slit 7 is made of coated aluminum alloy. Coated aluminum alloy material has the characteristics of being resistant to deformation and opaque to light.

[0073] In some embodiments, the laser source 1 employs a fundamental mode TEM with a wavelength of 532 nm. 00 Green laser.

[0074] In some embodiments, a method for generating a scalar vortex beam based on coaxial conventional holography and a method based on coaxial polarized holography is provided. This method uses a polarization-sensitive material PQ / PMMA as a medium. Under coaxial recording conditions, information exhibiting scalar vortex beam characteristics is recorded into the polarization-sensitive material PQ / PMMA using a real-time recording system designed with a combination of commonly used, inexpensive optical components. The polarization-sensitive material PQ / PMMA containing the scalar vortex beam can be used as a single device, offering advantages such as small size, low fabrication cost, and short processing time. The difference between the methods for generating scalar vortex beams based on coaxial conventional holography and polarized holography lies in the different polarization states of the two coherent lights used during interference recording. The two coherent lights used in the coaxial conventional holography method have the same polarization state, both being linearly polarized in a certain vibration direction. However, the two coherent lights used in the coaxial polarized holography method have mutually orthogonal polarization states, for example, linearly polarized light at 45° and -45° directions. The usage of the scalar vortex beam device and the beam diffraction efficiency of the two methods also differ. The former requires illumination with specifically linearly polarized light to generate a scalar vortex beam, but its generated beam has high diffraction efficiency. The latter, however, can generate a scalar vortex beam using any polarized light, and the polarization state of the resulting beam is related to the polarization state of the illuminating light. For example, when the recording signal light and reference light are linearly polarized at 45° and -45° respectively, their polarization states are simply opposite in direction. However, its generated beam has lower diffraction efficiency than the former.

[0075] To achieve the above objectives, the following technical solutions are employed.

[0076] A scalar vortex beam generation system based on coaxial conventional or polarized holography includes a laser source 1, a beam expander system, a polarizing beam splitter 2, a beam splitter prism 11, a second reflector, a first reflector 8, a circular black cardboard (circular shield) assembly, a first aperture 3, a fan-shaped slit 7, a polarization-sensitive material PQ / PMMA (holographic recording material 13), a first half-wave plate 4, a quarter-wave plate 5, a polarizer, a rotating platform with software-controllable rotation speed (a first steering device and a second steering device), and a CCD camera 17. The laser source 1, beam expander system, second half-wave plate 9, polarizing beam splitter 2, second reflector, first reflector 8, the circular black cardboard assembly, first aperture 3, beam splitter prism 11, and first lens 12 constitute the coaxial holographic signal light and reference light interference recording conditions. Under coaxial conditions, the outer ring of the beam is the reference light, and the inner ring is the signal light. The polarization-sensitive material PQ / PMMA is placed at the focal point of the lens for interference. The fan-shaped slit 7 and the first half-wave plate 4 are respectively mounted on a rotating platform with software-controllable rotation speed to control their rotational speed ratio. They are placed together with the quarter-wave plate 5, the first polarizer 6, and the first 4f imaging system in the signal optical path. Phase modulation is achieved by introducing phase changes and specific polarization states through the half-wave plate, quarter-wave plate 5, and polarizer. The second 4f imaging system, the second half-wave plate 9, and the second polarizer 10 are placed together in the reference optical path. The signal light and reference light are combined using the beam splitter 11 and then converged by the first lens 12. Interference occurs at the polarization-sensitive PQ / PMMA recording medium, recording the information filtered by the fan-shaped slit 7 in real time. Introducing the 4f imaging system improves the quality of the propagated beam. The third lens 16, the second aperture 18, and the CCD camera 17 constitute an image acquisition and detection unit for capturing images of the reconstructed scalar vortex beam.

[0077] Using polarization-sensitive material PQ / PMMA as a medium, scalar vortex beam fabrication systems were designed under coaxial conditions using both conventional holography and polarized holography. This method incorporates commonly used components such as a first half-wave plate (4), a quarter-wave plate (5), a first polarizer (6), and a fan-shaped slit (7). The resulting real-time recording system can flexibly fabricate scalar vortex beams of different orders. During fabrication, the smaller the opening angle of the fan-shaped slit (7), the higher the accuracy of the obtained scalar vortex beam. Polarization-sensitive PQ / PMMA material used to record scalar vortex beams of fixed orders can be used as devices. Scalar vortex beam devices generated using coaxial conventional holography exhibit higher diffraction efficiency, while those generated using coaxial polarized holography are more flexible in responding to the polarization state of incident light. Due to the simple fabrication process and low cost of polarization-sensitive PQ / PMMA material, optical devices made using this material can solve the problems of complex processing and high fabrication costs associated with previous methods. Furthermore, the fabrication time can be significantly shortened due to the material's responsive characteristics.

[0078] Please see Figure 5 In another embodiment, a method for generating a scalar vortex beam using coaxial conventional or polarized holography, applied to the scalar vortex beam generation system of coaxial conventional or polarized holography described in the above embodiments, includes the following steps:

[0079] Step S510: The laser source generates laser light;

[0080] Step S520: The polarization beam splitter splits the laser beam generated by the laser source into reference light and signal light;

[0081] Step S530: The reference optical path delivers the reference light to the beam splitter prism;

[0082] Step S540: The signal optical path delivers the signal light to the beam splitter prism;

[0083] Step S550: The circular shielding plate on the first reflecting mirror 8 blocks the reference light in the reference light path to form a ring reference light;

[0084] Step S560: The adjustment system adjusts the rotational speed ratio between the first half-wave plate and the fan-shaped slit through the first steering device and the second steering device, and adjusts the phase and polarization state of the signal light in conjunction with the quarter-wave plate and the first polarizer for control.

[0085] Step S570: The first aperture limits the signal light after adjustment by the adjustment system;

[0086] Step S580: Combine the incident reference light and signal light using a beam splitter prism;

[0087] Step S590: After the combined beam is focused by the first lens, it is sent into the holographic recording material for interference recording.

[0088] A laser source 1 generates a light source, and a polarization beam splitter 2 splits the laser beam generated by the laser source 1 into a signal beam and a reference beam. The signal beam is transmitted through the signal beam path, and the reference beam is transmitted through the reference beam path. After the phase and polarization state of the signal beam are adjusted by the adjustment system on the signal beam path, it is sent to the beam splitter prism 11 through the first aperture 3. The reference beam is blocked by a circular shield on the first reflector 8 on the reference beam path to form a ring reference beam, which is then sent to the beam splitter prism 11. The beam splitter prism 11 combines the incoming signal beam and reference beam. The shielding by the circular shield ensures that the reference beam is in the outer ring of the combined beam, while the restriction by the first aperture 3 ensures that the signal beam is in the inner ring of the combined beam. The combined beam is then converged by the first lens 12 and interfered with and recorded by the holographic recording material 13, thereby generating a coaxial conventional scalar vortex beam or a scalar vortex beam of polarized holography. The components used are simple and low-cost, and the manufacturing process for generating coaxial traditional scalar vortex beams or polarized holographic scalar vortex beams is simple, solving the problems of complex processing and high preparation costs in existing methods.

[0089] In some embodiments, the following steps are also included:

[0090] The image acquisition unit captures the image of the scalar vortex beam reproduced by the holographic recording material 13.

[0091] Finally, it should be noted that although the above embodiments have been described in the text and drawings of this application, this should not limit the scope of patent protection of this application. Any technical solutions that are based on the essential concept of this application and utilize the content described in the text and drawings of this application, resulting in equivalent structural or procedural substitutions or modifications, as well as the direct or indirect application of the technical solutions of the above embodiments to other related technical fields, are all included within the scope of patent protection of this application.

Claims

1. A scalar vortex beam generation system for coaxial conventional or polarized holography, characterized in that, include: A laser source, used to generate laser light; A polarization beam splitter, used to split the laser light generated by a laser source into a reference beam and a signal beam; Reference optical path, the reference optical path being used to transmit the reference light; A signal optical path, wherein the signal optical path is used to transmit the signal light; An adjustment system and a first aperture are sequentially arranged on the signal optical path. The adjustment system includes a first half-wave plate, a quarter-wave plate, a first polarizer, a fan-shaped slit, a first steering device, and a second steering device. The first half-wave plate, the quarter-wave plate, the first polarizer, and the fan-shaped slit are arranged sequentially. The first steering device is used to rotate the first half-wave plate, and the second steering device is used to rotate the fan-shaped slit. The reference optical path is provided with a first reflecting mirror, a circular shield attached to the first reflecting mirror, a second half-wave plate and a second polarizer in sequence; A beam splitter prism is used to combine the reference light transmitted by the reference optical path and the signal optical path. The first lens is used to converge the beam of light after it has been combined by the beam splitter prism. A holographic recording material is disposed at the focal point of a first lens, and the holographic recording material is used to interfere with and record the light beam converged by the first lens.

2. The scalar vortex beam generation system for coaxial conventional or polarized holography according to claim 1, characterized in that, It also includes a beam expander system disposed between the laser source and the polarization beam splitter.

3. The scalar vortex beam generation system for coaxial conventional or polarized holography according to claim 2, characterized in that, The beam expander system includes a spatial filter and a second lens.

4. The scalar vortex beam generation system for coaxial conventional or polarized holography according to claim 1, characterized in that, The opening angle of the fan-shaped slit is 0°-5°.

5. The scalar vortex beam generation system for coaxial conventional or polarized holography according to claim 1, characterized in that, The holographic recording material is a polarization-sensitive material, PQ / PMMA.

6. The scalar vortex beam generation system for coaxial conventional or polarized holography according to claim 1, characterized in that, It also includes an image acquisition unit; The image acquisition unit is used to capture images of the scalar vortex beam reproduced by the holographic recording material, and the image acquisition unit includes a third lens and a camera.

7. The scalar vortex beam generation system for coaxial conventional or polarized holography according to claim 6, characterized in that, The image acquisition unit also includes a second aperture, which is disposed between the third lens and the camera.

8. The scalar vortex beam generation system for coaxial conventional or polarized holography according to claim 1, characterized in that, The fan-shaped slit is made of coated aluminum alloy.

9. A method for generating a scalar vortex beam in coaxial conventional or polarized holography, applied to the scalar vortex beam generation system of coaxial conventional or polarized holography as described in any one of claims 1-8, characterized in that, Includes the following steps: Laser light sources generate laser light; A polarization beam splitter splits the laser beam generated by a laser source into a reference beam and a signal beam. The reference optical path delivers the reference light to the beam splitter; The signal optical path delivers the signal light to the beam splitter prism; The circular shield on the first reflecting mirror blocks the reference light in the reference light path, forming a ring-shaped reference light; The adjustment system adjusts the rotational speed ratio between the first half-wave plate and the fan-shaped slit through the first steering device and the second steering device, and adjusts the phase and polarization state of the signal light in conjunction with the quarter-wave plate and the first polarizer for control. The first aperture limits the signal light after it has been regulated by the regulation system; The incident reference light and signal light are combined using a beam splitter prism. The combined beam is focused by the first lens and then sent to the holographic recording material for interference recording.

10. The method for generating a scalar vortex beam in coaxial conventional or polarized holography according to claim 9, characterized in that, It also includes the following steps: The image acquisition unit captures the image of the scalar vortex beam reproduced by the holographic recording material.

Images