A vortex beam selector based on a fiber-particle helix structure

Abstract

The utility model discloses a kind of vortex light beam selectors based on optical fiber-particle helical structure, with single-mode fiber as base, spiral metal nanoparticle array is processed on the cladding surface of single-mode fiber by electron beam lithography or focused ion beam etching technology;The metal nanoparticle is distributed according to helical trajectory, and the absolute value of spiral period number is equal to the topological charge number of target vortex light, and the direction of rotation of metal nanoparticle is consistent with the direction of rotation of target vortex light topological charge number.The utility model realizes the high selectivity screening of target vortex light, and can be directly connected to existing optical fiber communication and sensing system, without additional spatial optical conversion module, integration is significantly better than conventional screening device.

Description

Technical Field

[0001] This invention relates to the field of interdisciplinary technology of nanophotonics and fiber optic devices, specifically a vortex beam selector based on a fiber-particle spiral structure. Background Technology

[0002] As a special type of beam with a helical phase wavefront and carrying orbital angular momentum (OAM), vortex beams theoretically have a topological charge that can take any integer value. Vortex beams carrying different topological charges are orthogonal to each other and can jointly form an infinite-dimensional optical communication channel. They have shown irreplaceable application value in cutting-edge fields such as optical communication (e.g., multi-channel signal transmission), quantum information processing (e.g., quantum state encoding), and micro-nano manipulation (e.g., particle capture and rotation).

[0003] However, the current development of vortex beam-related functional devices still faces three major technological bottlenecks: First, existing vortex beam screening and identification devices mostly rely on space optical systems (such as holographic gratings and interferometers), which suffer from drawbacks such as large size (usually requiring tens of square centimeters of installation space), low integration (difficult to directly interface with fiber optic systems), and weak anti-interference capability (susceptible to environmental vibrations and stray light), failing to meet the urgent need for miniaturized, on-chip integrated devices in the field of nanophotonics; Second, fiber-based vortex beam manipulation devices have limited functionality, mostly only capable of generating vortex beams (such as fiber grating-type vortex beam generators) or transmitting them (such as few-mode fibers), lacking screening and identification functions that combine high selectivity (target topological charge number recognition rate ≥90%) and high sensitivity (capable of responding to microwatt-level incident light); Third, existing screening technologies lack sufficient accuracy in distinguishing topological charges, especially in cases with multiple topological charges (such as... , , Crosstalk (typically >15%) is prone to occur during the separation of mixed beams, limiting its application in multi-channel scenarios.

[0004] Therefore, developing a miniaturized, highly selective, and integrable vortex beam selector based on an optical fiber platform to achieve precise screening and targeted response of vortex beams with specific topological charge numbers has become an urgent technical problem to be solved in this field. Utility Model Content

[0005] The purpose of this invention is to provide a vortex beam selector based on an optical fiber-particle spiral structure, which can excite resonance effects based on topological charge number, with one particle spiral structure targeting one topological charge number, thereby achieving precise selection of the vortex beam.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] This invention provides a vortex beam selector based on an optical fiber-particle spiral structure, using a single-mode optical fiber as a substrate and processing a spiral metal nanoparticle array on the cladding surface of the single-mode optical fiber.

[0008] The metal nanoparticles are distributed along a helical trajectory, and the number of helical periods is equal to the absolute value of the topological charge of the target vortex light, and the direction of rotation of the metal nanoparticles is consistent with the direction of rotation of the topological charge of the target vortex light.

[0009] Preferably, the vortex beam selector is fabricated on the cladding surface of a single-mode optical fiber using electron beam lithography or focused ion beam etching technology to process a spiral metal nanoparticle array.

[0010] Preferably, the single-mode optical fiber has a core diameter of 8-10 μm, a cladding thickness of 124 μm, and an overall optical fiber diameter of 125 μm.

[0011] Preferably, the length of the single-mode optical fiber is cut as needed, with a minimum length ≥2µm.

[0012] Preferably, the metal nanoparticles are spherical nanoparticles made of gold or silver.

[0013] Preferably, the diameter of the metal nanoparticles is 10-100 nm.

[0014] Preferably, the length of the spiral metal nanoparticle array is required to absorb less than 10% of the energy of the vortex light corresponding to the topological charge number.

[0015] Preferably, the single-mode fiber supports the integration of multiple arrays of metal nanoparticles corresponding to target vortex beams with different topological charge numbers.

[0016] Preferably, each group of the metal nanoparticle arrays is arranged independently with a spacing of not less than 500 nm.

[0017] The beneficial effects achieved by this utility model are as follows:

[0018] (1) Vortex beam filtering effect: When the incident beam contains vortex light that matches the topological charge number, under the excitation of the SLR effect, the absorption efficiency of the target vortex light is ≥90% and the transmittance is ≤5%; the absorption efficiency of the vortex light with unmatched topological charge number is ≤10% and the transmittance is ≥85%, thus achieving high selective filtering of the target vortex light.

[0019] (2) Localized strong field effect: After SLR excitation, localized plasmon polaritons are formed on the surface of metal nanoparticles, and their electric field intensity can reach 10²-10³ times that of the incident light field, forming a "hot spot array". The spatial size of the hot spot region is ≤50nm (much smaller than the diffraction limit), and the energy density is ≥10 6The energy concentration is W / cm², and the energy is mainly concentrated on the particle surface and in the interparticle space, with no significant outward radiation, ensuring efficient localization of energy.

[0020] (3) Integration advantages: The overall size of the vortex beam selector designed in this utility model is consistent with that of conventional optical fiber, and the length can be cut as needed. It can be directly connected to existing optical fiber communication and sensing systems without the need for additional spatial optical conversion modules. Its integration is significantly better than that of traditional screening devices. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the isophase surface distribution of vortex beams with topological charges of -1, 1, 2, and 3, respectively.

[0022] Figure 2 This is a schematic diagram showing the one-to-one correspondence between the surface lattice resonance effect of the particle spiral array structure and the vortex beam in this utility model;

[0023] Figure 3 The present invention provides a solution for topological charge number A schematic diagram of a vortex beam selector with an optical fiber-particle spiral structure.

[0024] Figure 4 This is a schematic diagram of a multi-topology charge number serial screening optical sensor, which is an application example of this utility model.

[0025] Figure 5 This is a schematic diagram of an encoding switch based on a Y-shaped optical fiber structure, which is an application example 2 of this utility model. Detailed Implementation

[0026] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The embodiments described below with reference to the accompanying drawings are illustrative and intended to explain this utility model, and should not be construed as limiting this utility model.

[0027] In the description of this utility model, it should be noted that the terms "upper", "lower", "front", "rear", "end", "bottom", "side", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0028] In this utility model, unless otherwise explicitly specified and limited, the terms "connection," "installation," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a direct connection, or a connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0029] Secondly, the term "an embodiment" or "embodiment" as used in this utility model refers to a specific feature, structure, or characteristic that can be included in at least one implementation of this utility model. The phrase "in an embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that excludes other embodiments.

[0030] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0031] The phase distribution of the vortex beam satisfies The mathematical relationship (where, For topological load number, (Azimuth angle), its wavefront exhibits a continuously spiraling upward spatial morphology, topological charge number The absolute value of determines the number of spiral cycles the wavefront completes in one revolution around the optical axis, and the phase gradient is . ( (where the distance is radial). This phase characteristic directly determines that the electric field distribution of the vortex beam has axisymmetry, and its amplitude is zero at the center of the optical axis, forming a unique "hollow" optical field distribution.

[0032] when When taken as a positive integer, the wavefront exhibits a right-handed spiral distribution. When taking negative integers, the wavefront exhibits a left-handed spiral distribution. The wavefront structure of vortex beams with equal positive and negative topological charge numbers is mirror-symmetric (parity is opposite).

[0033] When the topological charge of the vortex beam When changes occur, the wavefront shape of the light beam also changes, forming different numbers of spiral periods. Specifically, Figure 1 The image shows the wavefront structure of vortex light under different topological charge numbers. At that time, the wavefront exhibits a left-handed helical structure, while Then it is a right-handed helical structure. As the topological charge increases, the number of rotational periods of the wavefront also increases; for example, compared to... In this situation, and The corresponding wavefront has more helical structures. This characteristic of vortex light makes the spatial distribution of the phase corresponding to each topological charge number unique, which makes it possible for this invention to excite resonance of specific structures based on this phase spatial distribution.

[0034] The goal of this invention is to find a uniquely matching resonant structure for each topological charge number on the optical fiber platform, much like a key opening a lock. The physical mechanism that enables this pairing relationship is the surface lattice resonance effect. This, in turn, achieves highly selective screening of the target vortex light.

[0035] Surface lattice resonance (SLR) is a collective resonance effect unique to helical metallic nanoparticle arrays. Its core is a hybrid resonance mode formed by the synergistic coupling of the localized surface plasmon resonance (LSPR) of a single particle with the periodic diffraction grating modes of the array. Compared to the LSPR of a single particle, SLR suppresses the radiation loss of a single particle through long-range diffraction coupling of the array. This not only significantly enhances the local light field intensity but also possesses a high quality factor (Q-factor) and narrow spectral response, enabling highly selective capture and response to specific light fields.

[0036] The excitation of this effect requires specific conditions: on the one hand, it depends on the material and size characteristics of the metal nanoparticles (such as the strong plasma response of noble metals like gold and silver in the visible-near-infrared band); on the other hand, it requires a precise match between the spatial distribution of the incident light field and the periodicity and symmetry of the array structure. Both are indispensable. Its resonant wavelength typically satisfies the following relationship: (in For environmental refractive index, (for the array period), that is, conforming to The conditions under which an anomaly occurs.

[0037] Figure 2 The figure shows the one-to-one correspondence between the surface lattice resonance effect of the particle helical array structure and the vortex beam. In the figure, 005-008 are the isophase surfaces of the vortex beams with topological charges of -2, -1, 1, and 2, respectively. The second row, 001-004, are four types of helical particle array structures.

[0038] Based on the coupled dipole approximation, the key to the surface lattice resonance effect of excited particle helical structures lies in ensuring that each particle is treated equally in the excitation field. Specifically, this requires two conditions: first, the particles must possess symmetry within the array, guaranteed by the rotational and translational invariance of the entire array; second, the particles must occupy identical positions in the external field, requiring a matching relationship between the helical structure of the particles and the equiphase surface of the excited vortex light field. Figure 2 The four particle array structures and four vortex beams drawn in the figure are examples of the isophase surfaces.

[0039] Assuming that, through wavelength matching, selection of particle size and materials, and design of array structural parameters, we have found a single-helix particle array structure 001, which, under the excitation of a vortex beam 007 with a topological charge of +1, can excite the resonance effect of the structure, achieve localized enhancement of the electromagnetic field around the array, and strongly absorb the energy of the vortex beam through the resonance effect.

[0040] It should be noted that the adjustable parameters include the radius of the spiral particle array, the excitation wavelength, the particle size and dimensions, as well as the angle between adjacent particles in the spiral array. By adjusting these parameters, the 001 single chain can resonate with the 007 basic vortex light.

[0041] Based on the mirror relationship, the mirror structure of the single-helix particle array structure 001, the single-helix particle array structure 002, can necessarily excite surface lattice resonance under the irradiation of the vortex light 006, which is mirror-relational with the vortex light 007.

[0042] Similarly, based on rotational symmetry, if the single-helix particle array structure 001 resonates with the vortex beam 007, then the spatial distribution of the double-helix particle array structure 003 matches the phase distribution of the vortex beam 008 with a topological charge of 2. Therefore, the double-helix particle array structure 003 can necessarily resonate under the excitation of the vortex beam 008. Finally, based on the mirror relationship, the double-helix particle array structure 004 also resonates under the illumination of the vortex beam 005. These relationships can be further deduced. Ultimately, theoretically, based on the one-to-one correspondence between particle array structures and vortex beams, a corresponding resonant structure can be designed for all vortex beams with integer topological charges.

[0043] It should also be noted that, due to the matching relationship between the particle array structure and the isophase surface of the vortex beam, the above-mentioned particle array structures can only resonate with one topological charge number.

[0044] We discovered the specific matching mechanism between vortex light and particle arrays as follows:

[0045] like Figure 2 As shown, the SLR effect excitation of vortex light (labeled 005, 006, 007, 008) and helical metal nanoparticle arrays (labeled 004, 002, 001, 003) follows the matching principle of "topological charge number, helical period (phase structure) corresponding to particle array structure". The specific correspondence and mechanism of action are as follows:

[0046] 1. Clarify the correspondence: Vortex light 005 (topological charge number) The left-handed vortex light corresponds to particle array 004 (left-handed double-helix nanoparticle array, with a helix period of 2); vortex light 006 ( The left-handed vortex light corresponds to particle array 002 (left-handed single-helix nanoparticle array, with a helix period of 1); vortex light 007 ( The right-handed vortex light corresponds to particle array 001 (right-handed single-helix nanoparticle array, with a helix period of 1); vortex light 008 ( The right-handed vortex light corresponds to the particle array 003 (right-handed double-helix nanoparticle array with a helix period of 2). For other topological charges, corresponding particle helical structures can also be designed to achieve a one-to-one match between array resonance and topological charge.

[0047] 2. Matching Logic: When vortex light is incident, its helical phase distribution forms a "locking" effect with the spatial helical structure of the particle array. Only when the absolute value of the topological charge of the vortex light is equal to the number of helical periods of the array and the helical direction (left-handed / right-handed) is completely consistent, can the electric field vector of the light field resonate and couple efficiently with the free electrons on the particle surface, thereby exciting the SLR effect. At this time, the array will produce strong absorption and local field enhancement of the vortex light; if any one of the three is mismatched (e.g., ... If the vortex light is incident on the 002 array, effective coupling cannot be formed, and the vortex light is only transmitted or scattered, so the SLR effect cannot be excited.

[0048] 3. In the above discussion, the topological charge of particle array 001 and vortex light... The matching relationship between them is the key technical aspect of the entire design and the foundation and starting point for establishing the corresponding resonant structures for all topological charge numbers. The design and optimization of single-helix structures can employ the following strategies:

[0049] (1) Wavelength tuning: Adjust the center wavelength of the incident vortex light to precisely match the plasma resonance wavelength of the metal particles (gold, silver, etc.) to maximize the coupling efficiency of LSPR and array diffraction and enhance the intensity of SLR effect.

[0050] (2) Structural optimization: Finely adjust geometric parameters such as particle size (10-100nm) and array pitch (100-500nm) to optimize the periodicity and symmetry of the array, while suppressing the interference of unmatched topological charge vortex light and reducing detection crosstalk.

[0051] In summary, a design was developed specifically for topological load numbers. The spiral metal nanoparticle array is the starting point and foundation of the entire technical solution. This utility model patent provides the core physical basis for high selectivity and high sensitivity screening of vortex light with specific topological charge numbers through the matching mechanism of SLR effect and vortex light, and also lays the structural foundation for the integration and multifunctional expansion of the device.

[0052] 4. Based on the topological load number The spiral metal nanoparticle array was designed to produce corresponding structures with other topological charges.

[0053] Figure 2 Medium particle array 002 (corresponding to) Vortex light) and particle array 001 (corresponding to The vortex light exhibits a strictly mirror-symmetric structure, a design derived from the parity conservation law of the SLR effect. A mirror-symmetric particle array has resonance modes with parity opposite to the original structure, and can only be resonated by light fields with opposite parity (i.e., those with topological charge of 0). The vortex light is excited by the vortex light, thereby achieving accurate differentiation between positive and negative topological charge vortex light.

[0054] Based on this characteristic, without redesigning a completely new structure, it is possible to quickly expand to cover all integer topological loads simply by mirroring or rotating the array corresponding to a single topological load. The series of particle arrays greatly simplifies the design and fabrication process of multi-topology charge-response devices.

[0055] Based on the above theoretical foundation, this invention designs a vortex beam selector based on a fiber-particle spiral structure, employing an integrated structure of "fiber-spiral metal nanoparticle array" to achieve highly selective screening of target vortex light. See also Figure 3 Its specific structure is as follows:

[0056] This invention relates to a vortex beam selector based on single-mode optical fiber, which consists of a core and a cladding. A helical metal nanoparticle array is fabricated on the surface of the fiber cladding, achieving a high degree of integration between the fiber and the particle array, allowing direct connection to existing fiber optic systems. Based on the above principle analysis, this structure can achieve a one-to-one resonance effect for specific topological charges, primarily fulfilling two functions: first, exciting a localized electromagnetic field with ultra-high intensity at the location of the particle array structure; and second, strongly absorbing the energy of the corresponding vortex beam.

[0057] Furthermore, spiral metal nanoparticle arrays can be fabricated using electron beam lithography or focused ion beam etching techniques.

[0058] It should be noted that in this invention, the core diameter of the single-mode optical fiber is 8-10 μm, the cladding thickness is 124 μm, and the overall diameter of the optical fiber is 125 μm.

[0059] In this invention, the specific parameters of the spiral metal nanoparticle array are designed as follows:

[0060] Particle material and morphology: The particles are spherical nanoparticles made of gold (Au) or silver (Ag), with a diameter of 10-100nm, utilizing their strong plasmonic resonance response characteristics in the visible-near infrared band.

[0061] Array arrangement and topological charge matching: The metal nanoparticles are distributed along a helical trajectory, and the number of helical periods strictly corresponds to the absolute value of the topological charge of the target vortex light. For example... Figure 3 As shown, for The vortex light, the spiral period number of the metal nanoparticle array is 1; for The vortex light has a spiral period of 2 in the metal nanoparticle array, and the spiral direction is consistent with the spiral direction of the topological charge (left-handed / right-handed).

[0062] Array partitioning: Multiple arrays with different topological loads can be integrated simultaneously (e.g., Figure 3 It contains and The array is divided into partitions, with each group of arrays arranged independently and the partition spacing not less than 500nm to avoid crosstalk between groups.

[0063] It should be noted that the helical trajectory of the metal nanoparticles in this invention is optimized and matched according to the specific application scenario, the type of optical fiber, and the spatial distribution of the excitation mode.

[0064] It should be noted that when integrating multiple arrays corresponding to different topological charge numbers, the length of each array should be sufficient to fully absorb the energy of the corresponding mode. For example, the energy of vortex light corresponding to the topological charge number should be absorbed to less than 10%. Two applications are given later. The first application is to excite local field strength, where the length requirement is not high. The second application requires encoding, which requires the complete absorption of the energy of a certain type of vortex light. In this case, the length requirement should be specified.

[0065] By adopting the above-described structure of this utility model, the following technical effects can be achieved:

[0066] A. Vortex beam filtering effect: When the incident beam contains vortex light that matches the topological charge number, under SLR effect excitation, the absorption efficiency of the target vortex light is ≥90% and the transmittance is ≤5%; the absorption efficiency of the vortex light with unmatched topological charge number is ≤10% and the transmittance is ≥85%, thus achieving high selective filtering of the target vortex light.

[0067] B. Localized Strong Field Effect: After SLR excitation, localized plasmon polaritons form on the surface of metal nanoparticles, with an electric field intensity reaching 10²-10³ times that of the incident light field, forming a "hot spot array". The spatial size of the hot spot region is ≤50nm (much smaller than the diffraction limit), and the energy density is ≥10⁻⁶. 6 The energy concentration is W / cm², and the energy is mainly concentrated on the particle surface and in the interparticle space, with no significant outward radiation, ensuring efficient localization of energy.

[0068] C. Integration advantages: The overall size of this design device is consistent with that of conventional optical fiber (the length can be cut as needed, with a minimum length of ≥2um). It can be directly connected to existing optical fiber communication and sensing systems without the need for additional spatial optical conversion modules. Its integration level is significantly better than that of traditional screening devices.

[0069] Application Case 1: Multi-topology charge number serial screening optical sensor

[0070] like Figure 4 The multi-topology charge number serial screening optical sensor shown adopts a serial structure of "multi-sensor cascade - one-to-one correspondence of topology charge number", and optical sensors A (corresponding to) are set up sequentially. ), Optical sensor B (corresponding) ), optical sensor C (corresponding) ), optical sensor D (corresponding) (More sensors can be added as needed). Optical sensors A, B, C, and D are based on the interaction between light and matter and can be excited under strong electromagnetic fields, such as the SERS structure used for spectral testing. When containing... When a mixed vortex beam is incident, it passes sequentially through each sensor: only when the topological charge of the vortex beam matches the preset topological charge of the sensor will the resonance effect of the particle array be excited, providing energy to nearby sensors; vortex beams with mismatched topological charges are transmitted to the next level sensor with almost no loss until they match the sensor with the corresponding topological charge. If a switch at a certain level does not have a corresponding vortex beam input, it will not be excited. This cascaded design avoids the crosstalk problem of simultaneous detection of multiple topological charges and achieves accurate differentiation and sensitive detection of vortex beams with different topological charges through a "serial screening-response-by-response" mechanism.

[0071] This sensor, with its highly specific screening capabilities across cascaded single channels and compact fiber optic integration, enables parallel detection of multiple biomarkers in the field of biosensing by assigning unique topological charges to different biomarkers through sensor cascading. Simultaneously, the localized strong field effect amplifies trace biomarker signals, enhancing detection sensitivity. In environmental monitoring, different pollutants correspond to different topological charges; by utilizing the sensor's precise identification of topological charges, combined with spectral analysis, multiple pollutants can be simultaneously distinguished. Future applications can be expanded to high-end scenarios such as orbital angular momentum state sorting in quantum communication and multi-dimensional signal recognition in high-speed optical communication.

[0072] Application Case 2: Optical Encoded Switch (Based on Y-type Fiber Integration)

[0073] like Figure 5 The coded switch shown is based on a Y-type fiber structure and uses a 1×2 Y-type fiber structure. The two branches each integrate an optical sensor A (corresponding to...). ) and optical sensor B (corresponding to Furthermore, the two sets of spiral particle arrays rotate only in opposite directions (their geometric parameters are completely identical). When containing When the vortex beam is incident:

[0074] If incident Vortex light, sensor A only ( No matching, output light intensity ≥ 0.1mW (denoted as "1"); Sensor B ( The SLR effect is excited, and the output light intensity is <0.1mW (denoted as "0"), which is encoded as "01".

[0075] If incident Vortex light, sensor B is unmatched (output "1"), sensor A excites the SLR effect (output "0"), encoded as "10";

[0076] If the incident is not vortex light (such as) (etc.), neither set of sensors is matched, the output light intensity is ≥0.1mW, and the code is "11";

[0077] When there is no incident light, both outputs are "0", encoded as "00", as shown in Table 1 below.

[0078] Table 1 Optical Encoding Switch Output

[0079]

[0080] Furthermore, the number of Y-type fiber branches can be increased (e.g., 1×3, 1×4 type), and different topology loads can be assigned to each branch. It can implement multi-base encoding (3 branches correspond to 8 combinations, 4 branches correspond to 16 combinations).

[0081] The encoding capacity increases exponentially with the number of topology payloads.

[0082] This optical switch features high-speed encoding (rate ≥1Gbps) and low bit error rate (≤10⁻⁻⁴). 6 With its fast response (≤10ns) characteristics, it is suitable for the field of optical fiber communication technology and can achieve fast encoding by means of vortex beam input.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications and substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A vortex beam selector based on an optical fiber-particle spiral structure, characterized in that, Using single-mode optical fiber as a substrate, a spiral metal nanoparticle array is fabricated on the cladding surface of the single-mode optical fiber. The metal nanoparticles are distributed along a helical trajectory, and the number of helical periods is equal to the absolute value of the topological charge of the target vortex light, and the direction of rotation of the metal nanoparticles is consistent with the direction of rotation of the topological charge of the target vortex light.

2. A vortex beam selector based on an optical fiber-particle spiral structure according to claim 1, characterized in that, The vortex beam selector fabricates a spiral metal nanoparticle array on the cladding surface of a single-mode optical fiber using electron beam lithography or focused ion beam etching techniques.

3. A vortex beam selector based on an optical fiber-particle spiral structure according to claim 1, characterized in that, The single-mode optical fiber has a core diameter of 8-10 μm, a cladding thickness of 124 μm, and an overall fiber diameter of 125 μm.

4. A vortex beam selector based on an optical fiber-particle spiral structure according to claim 3, characterized in that, The length of the single-mode fiber is cut as needed, with a minimum length of ≥2µm.

5. A vortex beam selector based on an optical fiber-particle spiral structure according to claim 1, characterized in that, The metal nanoparticles are spherical nanoparticles made of gold or silver.

6. A vortex beam selector based on an optical fiber-particle spiral structure according to claim 5, characterized in that, The diameter of the metal nanoparticles is 10-100 nm.

7. A vortex beam selector based on an optical fiber-particle spiral structure according to claim 1, characterized in that, The length of the spiral metal nanoparticle array is required to absorb less than 10% of the energy of the vortex light corresponding to the topological charge number.

8. A vortex beam selector based on an optical fiber-particle spiral structure according to claim 1, characterized in that, The single-mode fiber supports the integration of multiple sets of metal nanoparticle arrays corresponding to target vortex beams with different topological charge numbers.

9. A vortex beam selector based on an optical fiber-particle spiral structure according to claim 8, characterized in that, Each group of metal nanoparticle arrays is arranged independently, with a spacing of not less than 500 nm between the partitions.

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