Hollow-core anti-resonance optical fiber polarization filter based on SPR (Surface Plasmon Resonance) effect

Abstract

The invention belongs to the technical field of hollow-core anti-resonance optical fiber polarization filters, and relates to a hollow-core anti-resonance optical fiber polarization filter based on the SPR effect, an optical fiber comprises six cladding tubes, the six cladding tubes are arranged in a circumferential array, and the circumscribed circle parts of the six cladding tubes are fiber cores; a nesting tube is eccentrically arranged in each cladding tube, the nesting tube is internally tangent to the cladding tube, and the tangent point is the farthest distance from the center of the fiber core; one-third arc sections, close to the fiber core, of the inner walls of the two cladding tubes in the y-axis direction are coated with gold films; six cladding tubes of the optical fiber are tangent to the inner wall of the outer supporting tube. The outermost layer is arranged to be a perfect matching layer and connected with the outer supporting pipe. The hollow-core anti-resonance optical fiber polarization filter based on the SPR effect has the advantages of being simple in process, better in filter performance, easy to control structural parameters and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of hollow-core anti-resonance optical fiber polarization filters and relates to a hollow-core anti-resonance optical fiber polarization filter based on the SPR effect. Background Art

[0002] Hollow-core fiber is a type of optical waveguide capable of low-loss transmission in the mid-infrared band. It is widely used in fields such as gas spectroscopy, environmental monitoring, biomedicine, nanoimaging, and laser transmission. Unlike solid-core fiber, its light-guiding region is primarily concentrated within the air core, with only a minimal amount of light energy distributed within the cladding dielectric material. The advantage of hollow-core fiber over solid-core fiber lies in that propagating light waves within the air core significantly minimizes nonlinear effects, resulting in a higher damage threshold and lower transmission loss. Furthermore, hollow-core fiber offers greater structural design versatility, thus demonstrating significant research potential.

[0003] The surface plasmon resonance (SPR) effect is an optical phenomenon that occurs on dielectric and metal surfaces. In optical waveguides, when light reflects off a metal surface, it induces surface plasmon waves. When the wave vector of the incident light matches the wave vector of the surface plasmon waves, resonant coupling occurs, a phenomenon known as surface plasmon resonance (SPR). Researchers have introduced SPR into optical fibers, which is more conducive to the functional realization and performance improvement of optical devices.

[0004] Zhang et al. proposed a chalcogenide solid-core antiresonant fiber polarization filter. This study used a chalcogenide material as the substrate. They achieved the SPR effect by coating the inner wall of the cladding with a gold film, but the bandwidth was only 248 nm at 1.58 μm.

[0005] Ma et al. investigated a chalcogenide hollow-core antiresonant fiber polarization filter based on surface plasmon resonance. This study also used a chalcogenide material as the substrate. The core of the fiber was filled with air, and the SPR effect was stimulated by coating the inner cladding with a gold film. The filter bandwidth was only 320 nm at a wavelength of 3.02 μm.

[0006] In summary, the existing hollow-core anti-resonant fiber polarization filter has shortcomings such as narrow bandwidth. Summary of the Invention

[0007] To solve the above technical problems, the present invention proposes a hollow-core antiresonant fiber polarization filter based on the SPR effect, which has the advantages of simple process, better filter performance, and easy control of structural parameters.

[0008] The technical solution of the present invention to solve the above problems is: a hollow-core antiresonant fiber polarization filter based on the SPR effect, which is special in that:

[0009] The optical fiber includes six cladding tubes, which are arranged in a circular array. The circumscribed circular part of the six cladding tubes is the fiber core. A nested tube is eccentrically arranged inside each cladding tube. The nested tube is tangent to the cladding tube, and the tangent point is the farthest away from the center of the fiber core. The one-third arc segment of the inner wall of the two cladding tubes in the y-axis direction close to the fiber core is coated with a gold film. The six cladding tubes of the optical fiber are tangent to the inner wall of the outer support tube, and a perfect matching layer is provided on the outside of the outer support tube.

[0010] Furthermore, the outer support tube and the perfect matching layer are made of silicon dioxide.

[0011] Furthermore, the thickness rd of the gold film is 50 nm.

[0012] Furthermore, the nested tubes and cladding tubes are both made of silicon dioxide.

[0013] Furthermore, the core radius ra is 15 μm.

[0014] Furthermore, the inner diameters rc1 of the two nested tubes in the y-axis direction are 7.8 μm, and the inner diameters rc of the remaining nested tubes are 7 μm.

[0015] Furthermore, the inner diameter rb of the cladding tube is 10 μm.

[0016] Furthermore, the cladding tube wall thickness ta in the y-axis direction is 0.7 μm, and the remaining cladding tube wall thickness tb is 0.5 μm.

[0017] Furthermore, the thickness t1 of the outer support tube is 10 μm.

[0018] Furthermore, the thickness t2 of the perfect matching layer is 10 μm.

[0019] Furthermore, the wall thickness tb of the nested tube is 0.5 μm.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects:

[0021] 1. The present invention introduces nested tubes when designing the optical fiber structure, which can not only effectively reduce the basement membrane limit loss, but also make it more convenient to adjust the structural parameters;

[0022] 2. The base material used in the optical fiber of the present invention is silica, which is easier to obtain;

[0023] 3. The present invention only coats one-third of the arc segment when coating the cladding tube with gold film, thus saving materials;

[0024] 4. The hollow-core anti-resonant optical fiber filter of the present invention has a wider bandwidth and better performance;

[0025] 5. The present invention can effectively adjust the resonance wavelength by changing the thickness of the gold-plated cladding tube wall and the thickness of the gold film. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a cross-sectional view of the hollow-core anti-resonant fiber polarization filter proposed by the present invention;

[0027] Figure 2 In the figure, (a) is the relationship between the effective refractive index and confinement loss of the x-polarization fundamental mode and the y-polarization fundamental mode, as well as the effective refractive index of the SPP mode and wavelength, (b) is the x-polarization fundamental mode at 1.52 μm, (c) is the y-polarization fundamental mode at 1.52 μm, and (d) is the SPP mode at 1.52 μm;

[0028] Figure 3 In the figure, (a) is the ER under different L, (b) and (c) are the normalized output powers of x- and y-polarized light under different L;

[0029] Figure 4 In the figure, (a) is the limiting loss, (b) is the ER value when increasing ra from 15μm to 18μm, and (c) and (d) are the normalized output power;

[0030] Figure 5 In the figure, (a) is the limiting loss, (b) is the ER value when increasing rb from 10.0μm to 10.2μm, and (c) and (d) are the normalized output powers.

[0031] Figure 6 In the figure, (a) is the limiting loss, (b) is the ER value when rc is increased from 6.7μm to 7.0μm, and (c) and (d) are the normalized output power.

[0032] Figure 7 In the figure, (a) is the limiting loss, (b) the ER value when increasing rc1 from 7.5μm to 7.8μm, (c) and (d) the normalized output power;

[0033] Figure 8 In the figure, (a) is the limiting loss, (b) is the ER value when increasing rd from 35nm to 50nm, and (c) and (d) are the normalized output power;

[0034] Figure 9 In the figure, (a) is the limiting loss, (b) is the ER value when increasing ta from 0.69 μm to 0.71 μm, and (c) and (d) are the normalized output power.

[0035] Figure 10 In the figure, (a) is the limiting loss, (b) is the ER value when tb is increased from 0.3μm to 0.5μm, and (c) and (d) are the normalized output power;

[0036] Figure 11 ER values ​​under ideal conditions and (a) ±1%ra, (b) ±1%rc, (c) ±1%tb.

[0037] Reference numerals: 1-fiber core, 2-perfectly matched layer, 3-nested tube, 4-cladding tube, 5-gold film, 6-outer support tube. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention for which protection is claimed, but merely represents selected embodiments of the present invention.

[0039] The present invention proposes a 1550nm band hollow core anti-resonant fiber polarization filter based on the SPR effect, see Figure 1 The optical fiber includes a core 1, a perfectly matched layer 2, a nested tube 3, a cladding tube 4, a gold film 5, and an outer support tube 6.

[0040] The optical fiber has a circular structure and includes six cladding tubes 4 arranged in a circular array within an outer support tube 6. The circumscribed circular portion of the six cladding tubes 4 forms the fiber core 1. Each cladding tube 4 is eccentrically positioned within a nested tube 3, which is inscribed within the cladding tube 4 at the point of tangency farthest from the center of the fiber core 1. The inner wall of each of the two cladding tubes 4, located along the y-axis and proximal to the fiber core 1, is coated with a gold film. The outer support tube 6 is positioned externally on the optical fiber, with the six cladding tubes 4 tangent to the inner wall of the outer support tube 6. The outermost layer is a perfectly matched layer 2, which is connected to the outer support tube 6.

[0041] The perfect matching layer 2, nested tube 3, cladding tube 4, and outer support tube 6 are all made of silicon dioxide.

[0042] like Figure 1 As shown in Figure 1, the core radius is ra, the cladding radius is rb, the radius of the two nested tubes in the y-polarization direction is rc1, and the radius of the remaining nested tubes is rc. ta is the cladding wall thickness in the y-polarization direction, tb is the wall thickness of the remaining cladding tubes and all nested tubes, and rd is the gold film thickness. The initial structural parameters are shown in Table 1.

[0043] Table 1 Initial structural parameter values ​​of hollow-core antiresonant fiber polarization filter

[0044]

[0045] The proposed hollow-core antiresonant fiber structure was analyzed and calculated using the full-vector finite element method. The outermost blue region of the structure is the perfectly matched layer (PML), and the boundary conditions of the PML are set as scattering boundary conditions to further reduce the reflected energy. Figure 1 The middle gray area is air, which has a refractive index of approximately 1; the blue area is silicon dioxide; and the yellow area is metal. The effective refractive index of silicon dioxide in the structure can be calculated using the Sellmeier equation:

[0046]

[0047] Where λ is the wavelength, and the values ​​of the parameters a, b, c, and d are 1.516145274690862, -16038.47604587125, 2.295827906168151, and -153.0419078237780, respectively. The dielectric constant of gold is calculated using the Drude-Lorentz model:

[0048]

[0049] Where, ε m is the dielectric constant of the metal, ε ∞ is the high-frequency dielectric constant, ω D is the plasma frequency, ω is the angular frequency of light, γ D is the damping frequency, Ω L and Γ L represents the frequency and spectrum bandwidth of the Lorentz spectrum oscillation, ε ∞ =5.9673, Δε=1.09 is the weighting factor. The limiting loss formula of optical fiber is as follows:

[0050] α=8.686×2πIm(n eff )×10 6 / λ(3)

[0051] Where, the unit of limiting loss α is dB / m, Im(neff) is the imaginary part of the effective refractive index, and the unit of operating wavelength λ is μm. In addition, normalized output power, ER, and bandwidth are also important parameters that reflect the performance of the filter. The formula for normalized output power is as follows:

[0052] P out (x, t) = P in (x,y)exp[-α(x,y)(ln10 / 10)L](4)

[0053] Where, P out(x, y) is the output power of x and y polarized light, P in (x, y) is the input power of x and y polarized light, and its value is usually set to 1. L is the length of the fiber. The extinction ratio formula is as follows:

[0054] ER=20lg{exp[(α2-α1)L]}(5)

[0055] Where α1 and α2 are the confinement losses of the x-polarization fundamental mode and the y-polarization fundamental mode, respectively.

[0056] The model under the initial structural parameters was simulated. Figure 2 (a) shows the relationship between the confinement loss of the x-polarization fundamental mode and the y-polarization fundamental mode and the wavelength, and the relationship between the effective refractive index of the x-polarization fundamental mode, the y-polarization fundamental mode and the SPP mode and the wavelength. Figure 2 As can be seen in (a), at a wavelength of 1.52μm, the y-polarization fundamental mode loss is 2418.33dB / m, while the x-polarization fundamental mode loss is only 205.34dB / m. At 1.52μm, the y-polarization fundamental mode phase-matches with the SPP mode, resulting in energy coupling. This results in efficient light transfer from the fiber core to the metal surface, causing a significant increase in the y-polarization fundamental mode loss. Figure 2 (b) is the x-polarization fundamental mode diagram at a wavelength of 1.52 μm. Figure 2 (c) is the y-polarization fundamental mode diagram, Figure 2 (d) is the SPP mode field distribution diagram at a wavelength of 1.52μm.

[0057] The ER values ​​of the x-polarization fundamental mode and the y-polarization fundamental mode vary with the fiber length L, as shown in Figure 3 As shown in (a), it can be seen that at the same wavelength, the longer the fiber length, the larger the ER value. When the fiber length is 15 mm, the ER value reaches 320 dB, the bandwidth is 350 nm, and the wavelength range is from 1.48 μm to 1.83 μm. Figure 3 (b)-(c) show the normalized output power of the x-polarization fundamental mode and the y-polarization fundamental mode at different fiber lengths. When the fiber length is 3mm, 7mm, 11mm, and 15mm, at a wavelength of 1.52 microns, the normalized output power in the y-polarization direction is 0.16dB, 0.01dB, 0.001dB, and 0.0001dB, respectively. This shows that by selecting an appropriate fiber length, the y-polarization fundamental mode light near a wavelength of 1.52μm can be effectively filtered out to obtain x-polarization light. At the same time, the generation of SPR at the above wavelength makes the limiting loss of the y-polarization fundamental mode much greater than the limiting loss of the x-polarization fundamental mode, thereby achieving a higher ER. The results show that the designed HC-ARF filter has excellent filtering effect and an ultra-wide wavelength range.

[0058] In order to obtain the best filtering effect, the present invention studies the influence of structural parameters such as the core radius of the structure and the thickness of the gold mold on the performance of the polarization filter.

[0059] 1. Influence of core radius ra on polarization filter

[0060] The core radius ra is 1 μm apart, and the parameter changes from 15 μm to 18 μm. Other structural parameters remain unchanged. The x-polarization fundamental mode loss and y-polarization fundamental mode loss are shown in the figure. Figure 4 As shown in (a), Figure 4 (b) is the relationship between ER and wavelength under different core radii. Figure 4 As shown in (a), when the core radius increases from 15μm to 18μm, the limiting loss peak at a wavelength of 1.52μm does not move, but the limiting loss peak shows a downward trend. This is because as ra increases, the resonant coupling strength decreases and the phase matching condition changes. As the limiting loss peak shows a downward trend, Figure 4 The ER value in (b) also shows a downward trend. To avoid cladding tube overlap, the core radius ra is difficult to reduce further, and the core radius ra is finally selected to be 15μm. Figure 4 (c)-(d) are the normalized output powers under different polarization fundamental modes.

[0061] 2. Influence of cladding tube radius rb on polarization filter performance

[0062] The cladding tube radius rb increases from 10μm to 10.2μm at intervals of 0.1μm, and other parameters remain unchanged. The limiting loss diagrams of the x-polarization fundamental mode and the y-polarization fundamental mode are shown in Figure 5 (a) shows the relationship between ER and wavelength under different cladding tube radius, and 5 (c)-(d) shows the normalized output power under different polarization fundamental modes. Figure 5 As can be seen in (a), with the increase of the cladding tube radius rb, the limiting loss peak gradually decreases. This is because with the increase of rb, the radius of the cladding tube in the structure becomes larger, resulting in a smaller distance between the six cladding tubes, and the resonance between the y-polarization fundamental mode loss and the surface plasmon polarization (SPP) mode is weakened, resulting in a decrease in the y-polarization fundamental mode limiting loss peak. The gradual decrease in the limiting loss peak leads to a gradual decrease in the ER value, as shown in Figure 2. Figure 5 To avoid overlap between the cladding tube and the nested tube, the cladding tube radius rb is difficult to reduce further, and the cladding tube radius rb is finally selected to be 10μm.

[0063] 3. Influence of nested tube radius rc on polarization filter

[0064] Based on the optimal structural parameters obtained from the above research, the nested tube radius rc is set to increase from 6.7μm to 7μm at intervals of 0.1μm. The x-polarization fundamental mode and y-polarization fundamental mode loss diagrams are shown in Figure 2. Figure 6 (a) shows the relationship between ER and wavelength under different nested tube rc radii, and 6 (c)-(d) show the normalized output power of different polarization fundamental modes. Figure 6 As can be seen in (a), the limiting loss peak hardly changes or moves with the change of the nested tube radius rc. Therefore, the change of the nested tube radius rc has almost no effect on the ER and normalized output power, as shown in Figure 6 (b), 6(c)-(d). Therefore, the original data of rc is retained, and the nested tube radius rc is 7μm.

[0065] 4. Influence of nested tube radius rc1 on polarization filter

[0066] The nested tube radius rc1 increases from 7.5μm to 7.8μm at intervals of 0.1μm. Other parameters remain unchanged. The loss diagrams of the x-polarization fundamental mode and the y-polarization fundamental mode are as follows Figure 7 Figure 7(a) shows the relationship between ER and wavelength for different nested tube radii rc1, and Figures 7(c)-(d) show the normalized output power of different polarization fundamental modes. As can be seen from the figure, in the wavelength range of 1.40μm to 1.56μm, the increase in the nested tube radius rc1 leads to an increase in the y-polarization fundamental mode loss peak, but the y-polarization fundamental mode loss value fluctuates slightly in this band. In the wavelength range of 1.57μm to 1.85μm, it can be seen that different rc1s lead to large fluctuations in the y-polarization fundamental mode loss value. This is due to the change in phase matching conditions as the wavelength increases. Figure 7 (b), the ER value and normalized output power in 7(c)-(d) are also affected accordingly, and the nested tube radius rc1 is still determined to be 7.8μm for further discussion.

[0067] 5. Influence of gold film thickness rd on polarization filter performance

[0068] like Figure 8 As shown in (a), when rd increases from 35nm to 50nm at intervals of 5nm, the limiting loss peak of the y-polarization fundamental mode gradually increases with the increase of rd, and the peak moves toward the long wavelength direction. At the same time, it can be found that the limiting loss peak of the x-polarization fundamental mode also gradually increases, and the peak moves toward the long wavelength direction. The main reason for the increase is that when the gold film becomes thicker, more energy will be absorbed by the metal when the light hits the metal surface, and the resonant coupling will be enhanced, resulting in an increase in the limiting loss of the y-polarization fundamental mode. Figure 8 (b) It can be seen that as the rd thickness increases, the ER peak gradually increases and red shifts. The normalized output power is as follows Figure 8(c)-(d) Therefore, we choose rd as 50nm to continue the study.

[0069] 6. Influence of the gold-plated cladding tube wall thickness ta on the performance of polarization filters

[0070] The wall thickness of the gold-plated cladding tube ta increases from 0.69μm to 0.71μm in 0.1μm intervals, and other parameters remain unchanged. The loss diagrams of the x-polarization fundamental mode and the y-polarization fundamental mode are shown in the figure. Figure 9 Figure 9(a) shows the relationship between ER and wavelength for different gold-clad tube wall thicknesses, ta. Figures 9(c)-(d) show the normalized output power for different polarization fundamental modes. As ta increases from 0.69μm to 0.71μm, the position of the y-polarization loss peak shifts toward longer wavelengths, and the loss peak gradually increases. The x-polarization loss peak also shifts toward longer wavelengths. This is because as ta thickens, the resonance between the y-polarization fundamental mode loss and the surface plasmon polariton (SPP) mode strengthens, leading to an increase in the y-polarization fundamental mode confinement loss peak. Figure 9 ER and Figure 9 The normalized output power in (c)-(d) has all undergone a redshift, and the ER peak position has moved from 1.51μm to 1.57μm. It can be seen that changing the thickness of the gold-plated cladding tube wall can effectively adjust the position of the junction loss peak. We continue this discussion by setting ta to 0.70μm.

[0071] 7. Influence of nested tube wall thickness tb on polarization filter performance

[0072] The wall thickness of the nested tube tb increases from 0.3μm to 0.5μm at intervals of 0.1μm. Other parameters remain unchanged. The x-polarization and y-polarization fundamental mode loss diagrams are shown in Figure 10 Figure 10(a) shows the relationship between ER and wavelength for different nested tube wall thicknesses. Figures 10(c)-(d) show the normalized output power of the fundamental mode for different polarizations. As tb increases from 0.3μm to 0.5μm, the peak losses of the y-polarization fundamental mode are 2055.26dB / m, 2049.33dB / m, and 2007.42dB / m, respectively. The peak losses of the x-polarization fundamental mode are 203.27dB / m, 194.80dB / m, and 214.13dB / m, respectively. It can be seen that changes in the nested tube wall thickness tb have little effect on the peak limiting loss. The ER value and normalized output power remain almost unchanged. Therefore, the original data for the nested tube wall thickness tb are retained.

[0073] 8. Manufacturing tolerance

[0074] In the HC-ARF filter proposed in this invention, the real-time optimization of the drawing parameters during the optical fiber drawing process is a costly and time-consuming process that relies heavily on experimentation and error. Therefore, the manufacturing tolerance of each parameter was analyzed. Studies have found that 1% is a very large tolerance parameter. Therefore, the bandwidth and ER values ​​of this filter were calculated to determine whether the manufacturing tolerances of this filter were good. Figure 11 As can be seen from the figure, the ER value and bandwidth remain essentially unchanged when we change the core radius ra, the nested tube radius rc, and the nested tube wall thickness tb. This demonstrates that this polarization filter has excellent manufacturing tolerances.

[0075] In summary, the present invention proposes a hollow-core antiresonant fiber polarization filter based on the SPR effect. The hollow-core antiresonant fiber consists of six cladding tubes and nested tubes. The introduction of the nested tubes can effectively reduce the confinement loss of the core fundamental mode. The inner wall of the cladding tube is coated with gold in the y-polarization direction to stimulate the SPR effect. The finite element method is used to analyze the effects of different core radii, cladding tube radii, cladding tube wall thicknesses, and gold film thicknesses on the hollow-core antiresonant fiber filter. The results of the introduction of SPR show that when the fiber length is 15mm, the extinction ratio reaches 320dB and the bandwidth is 350nm, covering the wavelength range of 1.48μm to 1.83μm. In addition, the resonant wavelength can be adjusted by changing the thickness of the gold-plated cladding tube wall and the gold film thickness. When the parameters of the hollow-core antiresonant fiber filter deviate from ±1%, the operating bandwidth and wavelength remain almost unchanged. Therefore, the designed hollow-core antiresonant fiber filter has stable performance and has great application potential in fiber-optic communications, fiber-optic transmission, and other aspects.

[0076] The above descriptions are merely embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied to other related system fields, are also included in the scope of protection of the present invention.

Claims

1. A hollow-core antiresonant fiber polarization filter based on the SPR effect, characterized by: The optical fiber comprises six cladding tubes (4), the six cladding tubes (4) are arranged in a circumferential array, and the circumscribed circular portion of the six cladding tubes (4) is a fiber core (1); a nested tube (3) is eccentrically provided inside each cladding tube (4), and the nested tube (3) and the cladding tube (4) are internally tangent, with the tangent point being the farthest from the center of the fiber core (1); A gold film (5) is coated on the inner wall of the two cladding tubes (4) in the y-axis direction, on a third of the arc section close to the fiber core (1); The six cladding tubes (4) of the optical fiber are tangent to the inner wall of the outer support tube (6), and a perfect matching layer (2) is provided on the outside of the outer support tube (6).

2. The hollow-core antiresonant fiber polarization filter based on the SPR effect according to claim 1, characterized in that: The perfect matching layer (2) and the outer support tube (6) are both made of silicon dioxide.

3. The hollow-core antiresonant fiber polarization filter based on the SPR effect according to claim 2, characterized in that: The thickness rd of the gold film (5) is 50 nm.

4. The hollow-core antiresonant fiber polarization filter based on the SPR effect according to claim 3, characterized in that: The nested tube (3) and cladding tube (4) are both made of silicon dioxide.

5. A hollow-core antiresonant fiber polarization filter based on the SPR effect according to any one of claims 1 to 4, characterized in that: The radius ra of the fiber core (1) is 15 μm.

6. The hollow-core antiresonant fiber polarization filter based on the SPR effect according to claim 5, characterized in that: The inner diameter rc1 of the two nested tubes (3) in the y-axis direction is 7.8 μm, and the inner diameter rc of the remaining nested tubes is 7 μm.

7. The hollow-core antiresonant fiber polarization filter based on the SPR effect according to claim 6, characterized in that: The inner diameter rb of the cladding tube (4) is 10 μm.

8. The hollow-core antiresonant fiber polarization filter based on the SPR effect according to claim 7, characterized in that: The wall thickness ta of the cladding tube (4) in the y polarization direction is 0.7 μm, and the wall thickness ta of the remaining cladding tubes (4) is 0.5 μm.

9. The hollow-core antiresonant fiber polarization filter based on the SPR effect according to claim 8, characterized in that: The thickness t1 of the outer support tube (6) is 10 μm, and the thickness t2 of the perfect matching layer (2) is 10 μm.

10. The hollow-core antiresonant fiber polarization filter based on the SPR effect according to claim 9, characterized in that: The wall thickness tb of the nested tube (3) is 0.5 μm.

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