High-sensitivity photonic crystal fiber double-parameter sensor based on SPR effect

Abstract

The utility model discloses a high-sensitivity photonic crystal fiber double-parameter sensor based on SPR effect, comprising a substrate, a fiber core and a cladding are arranged on the substrate, two sides of the cladding are symmetrically and laterally polished to respectively form an upper polishing surface and a lower polishing surface, the upper polishing surface is sequentially provided with a plasmon material layer and a titanium dioxide layer, and the lower polishing surface is provided with a high-sensitivity photonic crystal fiber and a high-sensitivity photonic crystal fiber. A silver film layer is arranged on the lower polishing surface; a core air hole is formed in the center of the substrate, and outer-layer air holes which are arranged in a hexagonal structure by taking the core air hole as the center, middle-layer air holes which are arranged in a hexagonal structure by taking the core air hole as the center and inner-layer air holes which are arranged in a straight line are sequentially formed in the cladding outside the core air hole from outside to inside. According to the sensor disclosed by the utility model, the air holes are specially arranged, so that the refractive index and the temperature can be synchronously detected, and the sensor has relatively high maximum wavelength sensitivity and quality factor.

Description

Technical Field

[0001] This utility model relates to the field of fiber optic sensing technology, specifically to a high-sensitivity photonic crystal fiber dual-parameter sensor based on the SPR effect. Background Technology

[0002] In today's information age, sensing technology is the primary means of acquiring information in the natural and industrial fields. With the continuous advancement of science and technology, fiber optic sensing technology has become increasingly mature. Among these advancements, the discovery of combining the surface plasmon resonance (SPR) principle with microstructured optical fibers has further advanced fiber optic sensing technology. SPR is an optical phenomenon occurring on the surfaces of metals and dielectrics. This phenomenon was first discovered experimentally in 1902 by the American scholar R. W. Wood, and the first person to stimulate it was the German scholar Otto. When light waves undergo total internal reflection at a metal surface, evanescent waves are generated, and the free electrons within the metal undergo collective oscillations, thus generating surface plasmon waves at the metal-dielectric interface. If the evanescent wave generated by the incident light wave and the surface plasmon wave satisfy the phase-matching condition in their wave vector components parallel to the interface, the two waves will resonate. At this point, the energy of the evanescent wave and the energy of the surface plasmon wave undergo complete or incomplete coupling, leading to energy loss and reduced intensity of the reflected light wave, forming a trough in the reflection spectrum. This combined fiber optic sensing technology has many advantages, such as rapid detection, high sensitivity, and no need for labeling, and is widely used in communications, medical, and industrial fields.

[0003] SPR technology, with its advantages of being label-free, enabling real-time analysis, and exhibiting high sensitivity, has shown great application potential in the field of biomedical detection. Photonic crystal fiber (PCF), as a novel type of fiber, possesses unique optical properties, such as flexible dispersion characteristics and high birefringence. The PCF-SPR sensor, formed by combining PCF with SPR technology, offers a new approach to solving challenges in cancer detection and temperature measurement. The PCF-SPR sensor can utilize the special transmission characteristics of light in PCF and the surface plasmon resonance effect to achieve highly sensitive detection of biomolecules and temperature.

[0004] like:

[0005] Chinese patent application CN116952902A discloses a dual-D structure fiber optic sensor for simultaneous detection of refractive index and temperature. This fiber optic sensor includes a cladding layer containing a fiber core. A first channel is located at the bottom of the fiber core, and a second channel is located at the top. An inner hexagonal vent ring is located inside the fiber core, and an outer hexagonal vent ring is formed outside the inner hexagonal vent ring. A first circular hole is located at the bottom of the fiber core, directly above the first channel, and a second circular hole is located at the top of the fiber core, directly below the second channel. This invention, by designing a photonic crystal fiber with a dual-D structure based on surface plasmon resonance, enhances the core mode and surface plasmon mode, enabling simultaneous detection of the refractive index and operating temperature of liquid analytes. It can detect liquids with refractive indices between 1.31 and 1.36, with a wavelength sensitivity of 2180 nm / RIU and a temperature sensitivity of -0.31 nm / ℃ over an extremely wide operating temperature range of -25℃ to -150℃.

[0006] Chinese patent application CN115753683A discloses a D-type dual-core PCF-SPR refractive index sensor. A core single-hole is located at the center of the PCF cladding, surrounded by hexagonal outer air holes. Two symmetrical polished surfaces are formed on both sides of the PCF cladding region, creating a microchannel at the center. Au and TiO2 layers are sequentially applied to the outer ends of the polished surfaces. Coating the polished surfaces with a sensitizing material enhances the sensor's SPR effect. The double-sided polishing design with a central microchannel, combined with the core single-hole, creates a dual-core coupling effect between the evanescent wave generated by the fiber core and the Au-TiO2 coating on the polished surface, resulting in a more significant SPR effect. The sensor has an RI (refractive index) recognition range of 1.26–1.41 and a refractive index sensitivity as high as 24600 nm / RIU.

[0007] However, the sensitivity of the aforementioned sensors in detecting refractive index and temperature is still not ideal. Utility Model Content

[0008] The technical problem to be solved by this invention is to provide a high-sensitivity photonic crystal fiber dual-parameter sensor based on the SPR effect, which has higher refractive index and temperature sensitivity.

[0009] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0010] A high-sensitivity photonic crystal fiber dual-parameter sensor based on the SPR effect includes a substrate, a fiber core and a cladding disposed on the substrate, wherein:

[0011] The cladding is symmetrically side-polished to form two symmetrical polishing surfaces, namely an upper polishing surface and a lower polishing surface; a plasma exciton material layer and a titanium dioxide layer are sequentially provided on the upper polishing surface, and a silver film layer is provided on the lower polishing surface;

[0012] A core air hole is located at the center of the substrate. Within the cladding surrounding the core air hole, from the outside in, are arranged a series of air holes in a hexagonal pattern centered on the core air hole, a middle layer of air holes also in a hexagonal pattern centered on the core air hole, and an inner layer of air holes arranged in a straight line. The center points of the outer and middle layer air holes, the center of the core air hole, and the center of the substrate coincide.

[0013] The outer air vents include 4 small air vents and 10 large air vents. The 4 small air vents are symmetrically distributed along the X-axis, and the 10 large air vents are symmetrically distributed along the Y-axis. The small air vents are located close to the core air vents, and the large air vents are located outside the small air vents.

[0014] The intermediate air holes include two medium air holes and four large air holes, which are distributed on the vertices of the hexagon. The two medium air holes are symmetrically distributed along the Y-axis and are located between the core air holes and the upper polishing surface.

[0015] The inner air vent includes two large air vents, which are located on the X-axis and symmetrically arranged on the left and right sides of the core air vent.

[0016] The diameters of the small air holes, medium air holes, and large air holes increase from small to large, and the diameter of the core air hole is equal to that of the small air holes.

[0017] In the outer layer of air holes, the distance between the centers of any two adjacent air holes is equal; the distance between the centers of the two large air holes constituting the inner layer of air holes is equal to the distance between the centers of any two adjacent air holes in the outer layer of air holes; the distribution of three adjacent air holes in the middle layer of air holes and the inner layer of air holes all form an equilateral triangular lattice structure; the distance between the centers of two adjacent air holes in the middle layer of air holes and the outer layer of air holes in the X-axis direction is equal to the distance between the centers of any two adjacent air holes in the outer layer of air holes.

[0018] In this application, the substrate material is silicon dioxide. The center of the substrate coincides with the geometric center of the photonic crystal fiber.

[0019] Furthermore, the distance between the center of the substrate and the upper or lower polished surface is 7.0 ± 0.1 μm.

[0020] Furthermore, the diameters of the core air hole and the small air hole are both 0.55±0.1μm, the diameter of the medium air hole is 1.15±0.1μm, and the diameter of the large air hole is 1.85±0.1μm.

[0021] Furthermore, in the outer layer air pores, the distance between the centers of any two adjacent air pores is 3.28±0.1μm; the distance between the centers of the two large air pores constituting the inner layer air pores is 3.28±0.1μm; and the distance between the centers of two adjacent air pores in the X-axis direction of the middle layer air pores and the outer layer air pores is 3.28±0.1μm.

[0022] Furthermore, the span of both the plasmon resonance material layer and the titanium dioxide layer in the X-axis direction is 6.56 ± 0.2 μm. The plasmon resonance material layer is typically a gold film layer made of gold material, with a thickness of 45–55 nm; the thickness of the titanium dioxide layer is 50–60 nm.

[0023] Furthermore, the silver film layer has a span of 6.56±0.2μm in the X-axis direction and a thickness of 35~45nm.

[0024] Compared with the prior art, the features of this utility model are as follows:

[0025] 1. The two air holes below the polished surface in the outer layer are designed to be smaller than the other air holes, which makes the leakage channel of light from the fiber core to the plasmon resonance material layer wider, improves the coupling efficiency of evanescent waves and surface plasmon waves, enhances the SPR effect, and helps to improve sensitivity.

[0026] 2. Plasmon resonance (SPR) effects are generated by designing short-span plasmon resonance material layers, titanium dioxide layers, and silver films on the upper and lower polished surfaces along the X-axis. These layers are used to excite the SPR effect, which is achieved through the interaction of free electrons on the metal surface with light waves. Compared to sensors that fill the interior of air holes with material, the surface-coated structure is simpler to manufacture and allows for easier modification of the refractive index measurement range.

[0027] 3. The sensor of this invention can detect the refractive index of the analyte in the range of 1.360 to 1.401, and has a maximum wavelength sensitivity of up to 32000 nm / RIU, with a sensitivity of 914.29 RIU. -1 It has a high quality factor; and achieves a high wavelength sensitivity of -28.7 nm / ℃ in the temperature range of 0 to 50℃. Attached Figure Description

[0028] Figure 1 This is a two-dimensional structural diagram of the sensor described in this utility model.

[0029] Figure 2 The relationship between the effective real part of the refractive index of the core mode and the surface plasmon mode, and the confined loss spectrum of the core mode are shown when the refractive index RI = 1.381 of the analyte.

[0030] Figure 3 The confined loss spectrum in the X-polarization direction of the Core1 fiber mode is obtained when the refractive index of the analyte changes from 1.360 to 1.401.

[0031] Figure 4 This invention presents the correspondence between the refractive index of the sensor material and the resonant wavelength, as well as the fitting curve.

[0032] Figure 5 The relationship between the effective real part of the refractive index of the core mode and the surface plasmon mode, and the confined loss spectrum of the core mode, are shown at a temperature T = 20℃.

[0033] Figure 6 The confined loss spectrum in the X-polarization direction of Core 2 fiber mode when the temperature changes from 0℃ to 50℃.

[0034] Figure 7 This invention relates the relationship between ambient temperature and resonant wavelength of the sensor and the fitting curve.

[0035] The numbers on the map are:

[0036] 1. Substrate, 2. Outer layer air pores, 3. Middle layer air pores, 4. Core air pores, 5. Large air pores, 6. Medium air pores, 7. Small air pores, 8. Upper polished surface, 9. Plasmon resonance material layer, 10. Titanium dioxide layer, 11. Lower polished surface, 12. Silver film layer, 13. Analyte channel, 14. Perfect matching layer.

[0037] In the diagram, d1 represents the diameter of the large air hole, d2 represents the diameter of the small air hole or core air hole, d3 represents the diameter of the middle air hole, P represents the distance between the center of the core air hole and the center of one of the large air holes in the inner layer, 2P represents the distance between the centers of any two adjacent air holes in the outer layer, and also represents the distance between the centers of two adjacent air holes in the middle layer and the outer layer in the X-axis direction. Detailed Implementation

[0038] To better explain the technical solution of this utility model, the present utility model will be described in further detail below with reference to the accompanying drawings, but the embodiments of this utility model are not limited thereto.

[0039] Reference Figure 1The high-sensitivity photonic crystal fiber dual-parameter sensor based on the SPR effect described in this invention includes a main structure composed of photonic crystal fiber. A perfectly matched layer 14 is located on the outer layer of the photonic crystal fiber, serving as a computational boundary added during performance simulation of the fiber using the finite element method. The outer side of the photonic crystal fiber cladding and the perfectly matched layer 14 form a channel 13 for the analyte. The substrate 1 of the photonic crystal fiber is made of silicon dioxide, and a core and cladding are arranged on the substrate 1. The center of the substrate 1, the center of the cladding, and the geometric center of the photonic crystal fiber coincide.

[0040] The cladding is symmetrically polished on both sides to form two symmetrical polished surfaces, namely the upper polished surface 8 and the lower polished surface 11. The upper polished surface 8 is provided with a plasma exciton material layer 9 and a titanium dioxide layer 10 in sequence to excite the SPR effect and serve as a refractive index detection channel. The lower polished surface 11 is provided with a silver film layer 12, which interacts with the filled temperature-sensitive material to regulate the resonant wavelength drift by changing the dielectric constant of the silver film caused by changes in ambient temperature, and serves as a temperature detection channel.

[0041] In this invention, an xy rectangular coordinate system is established with the center of the base 1 as the origin. The X-axis direction is the direction of the x-axis in the xy coordinate system, and the Y-axis direction is the direction of the y-axis in the xy coordinate system.

[0042] A core air hole 4 is provided at the center of the substrate 1. Within the cladding surrounding the core air hole 4, from the outside in, there are sequentially arranged outer layer air holes 2 in a hexagonal structure centered on the core air hole 4, intermediate layer air holes 3 in a hexagonal structure centered on the core air hole 4, and inner layer air holes arranged in a straight line. The center points of the outer layer air holes 2, the intermediate layer air holes 3, and the center of the core air hole 4 all coincide with the center of the substrate 1.

[0043] The outer air hole 2 includes 4 small air holes 7 and 10 large air holes 5. The 4 small air holes 7 are symmetrically distributed along the X-axis, and the 10 large air holes 5 are symmetrically distributed along the Y-axis. The small air holes 7 are located close to the core air hole 4, and the large air holes 5 are located outside the small air holes 7.

[0044] The intermediate air hole 3 includes two medium air holes 6 and four large air holes 5, which are distributed on the vertices of the hexagon. The two medium air holes 6 are symmetrically distributed along the Y-axis and are located between the core air hole 4 and the upper polishing surface 8.

[0045] The inner air vents include two large air vents 5, which are located on the X-axis and symmetrically arranged on the left and right sides of the core air vent 4;

[0046] The diameters of the small air hole 7, the medium air hole 6, and the large air hole 5 increase from small to large, and the diameter of the core air hole 4 is equal to that of the small air hole 7.

[0047] In the outer layer air hole 2, the distance between the centers of any two adjacent air holes is equal; the distance between the centers of the two large air holes 5 that constitute the inner layer air hole is equal to the distance between the centers of any two adjacent air holes in the outer layer air hole 2; the distribution of the three adjacent air holes in the middle layer air hole 3 and the inner layer air hole is in an equilateral triangular lattice structure; the distance between the centers of two adjacent air holes in the middle layer air hole 3 and the outer layer air hole 2 in the X-axis direction is equal to the distance between the centers of any two adjacent air holes in the outer layer air hole 2.

[0048] When lateral polishing the cladding, the preferred polishing depth is to control the distance between the center of the substrate 1 and the upper polishing surface 8 or the lower polishing surface 11 to be 7.0 ± 0.1 μm.

[0049] The plasmon resonance material layer 9, titanium dioxide layer 10, and silver film layer 12 all have a span of 6.56 ± 0.2 μm along the X-axis and are evenly distributed on both sides of the center of the substrate 1. The plasmon resonance material layer 9 is typically a gold film layer made of gold material with a thickness of 45–55 nm; the titanium dioxide layer 10 has a thickness of 50–60 nm; and the silver film layer 12 has a thickness of 35–45 nm.

[0050] The outer air hole 2, the middle air hole 3, and the inner air hole are mainly used to reduce the refractive index to form a cladding, thus constituting a refractive index-guided photonic crystal fiber. Among them, the two small air holes 7 below the polished surface 8 in the outer air hole 2 mainly promote mode field leakage, allowing more light to be coupled to the surface of the metal thin film, improving coupling efficiency, enhancing the SPR effect, and contributing to improved sensitivity.

[0051] Preferably, the diameters of the core air hole 4 and the small air hole 7 are both 0.55±0.1μm, the diameter of the medium air hole 6 is 1.15±0.1μm, and the diameter of the large air hole 5 is 1.85±0.1μm.

[0052] Preferably, in the outer air hole 2, the distance between the centers of any two adjacent air holes is 3.28±0.1μm; the distance between the centers of the two large air holes 5 constituting the inner air hole is 3.28±0.1μm; and the distance between the centers of two adjacent air holes in the middle air hole 3 and the outer air hole 2 in the X-axis direction is 3.28±0.1μm.

[0053] The solid portions (Core 1 and Core 2) located on the upper and lower sides of the core air hole 4 are the fiber cores of the sensor described in this invention, supporting dual-channel optical field transmission to realize refractive index and temperature sensing functions respectively. Core 1 is located in the solid area above the core air hole 4, with two small air holes 7 in the outer layer air hole 2 above it and two medium air holes 6 in the middle layer air hole 3 on its sides; Core 2 is located in the solid area below the core air hole 4, with two small air holes 7 in the outer layer air hole 2 below it and two large air holes 5 in the middle layer air hole 3 on its sides.

[0054] In the sensor described in this utility model, the upper half of the analyte channel 13 is used to fill the analyte (liquid) with a refractive index analysis range of 1.360 to 1.401; the lower half of the analyte channel 13 is used to fill the temperature-sensitive material, specifically polydimethylsiloxane (PDMS); the temperature analysis range is 0 to 50°C.

[0055] Reference Figure 1 The structure is defined as follows: the diameter of the photonic crystal fiber is 19 μm; the plasmon polariton material layer 9 is a gold film layer with a thickness of 50 nm; the thickness of the titanium dioxide layer 10 is 55 nm; the thickness of the silver film layer 12 is 40 nm; the inner diameter of the analyte channel 13 is 19 μm and the outer diameter is 22 μm; the diameters of the core air hole 4 and the small air hole 7 are both 0.55 μm, the diameter of the medium air hole 6 is 1.15 μm, and the diameter of the large air hole 5 is 1.85 μm; the distance between the centers of any two adjacent air holes in the outer layer air hole 2 is 3.28 μm, and the distance between the centers of the two large air holes 5 constituting the inner layer air hole is 3.28 μm, that is, the distance between the center of the core air hole 4 and the center of one of the large air holes 5 in the inner layer air hole is 1.64 μm. A sensing model of the present invention is established using simulation software to simulate and calculate its sensing process.

[0056] The analyte is filled in the upper semi-annular portion of the analyte channel 13, i.e., the refractive index detection channel, to form a refractive index sensing channel. The dielectric constant of the gold film layer is defined by the Drude model, and the refractive index of the titanium dioxide layer 10 is related to the incident wavelength.

[0057] like Figure 2 As shown, the refractive index of the analyte is 1.381. When the evanescent wave generated by the incident light wave and the surface plasma wave satisfy the phase matching condition in their wave vector components parallel to the interface, the real part of the effective refractive index of the core mode is equal to the real part of the effective refractive index of the surface plasma mode. At this time, the confinement loss of the core mode at the resonant wavelength reaches its maximum value.

[0058] Changes in the refractive index of the analyte can cause a shift in the resonant wavelength, such as...Figure 3 As shown, the effective range of the refractive index of the analyte is 1.360 to 1.401. As the refractive index increases, the resonance wavelength redshifts.

[0059] The relationship between the refractive index of the analyte and the resonant wavelength is as follows: Figure 4 As shown, a polynomial fit was performed on the relationship between the two, and the fit coefficient was 0.9949.

[0060] In addition, the wavelength sensitivity and quality factor corresponding to each refractive index were calculated. The maximum wavelength sensitivity reached 32000 nm / RIU, and the maximum quality factor reached 914.29 RIU. -1 .

[0061] A temperature-sensitive material is filled into the lower semi-annular portion of the analyte channel 13, i.e., the temperature detection channel, to form a temperature sensing channel. For example... Figure 5 As shown, at a temperature of 20℃, when the evanescent wave generated by the incident light wave and the surface plasmonic wave satisfy the phase-matching condition in their wave vector components parallel to the interface, the real part of the effective refractive index of the core mode is equal to that of the surface plasmonic mode. At this point, the confinement loss of the core mode reaches its maximum value at the resonant wavelength. Changes in temperature will cause a shift in the resonant wavelength, such as... Figure 6 As shown, the temperature range is 0℃ to 50℃. With increasing temperature, the resonant wavelength undergoes a blue shift. The relationship between temperature and resonant wavelength is as follows: Figure 7 As shown, a polynomial fit was performed on the relationship between the two, with a fitting coefficient of 0.9992. The wavelength sensitivity corresponding to each temperature was calculated, with the highest wavelength sensitivity reaching -28.7 nm / ℃.

[0062] The above experiments demonstrate that the dual-parameter sensor based on surface plasmon resonance and double-sided polished D-type photonic crystal fiber of this invention exhibits excellent refractive index and temperature sensing performance. Within the refractive index range of the analyte (1.360–1.401), a high wavelength sensitivity of 32000 nm / RIU is achieved, with a sensitivity of 914.29 RIU. -1 It has a high quality factor; and achieves a high wavelength sensitivity of -28.7 nm / ℃ in the temperature range of 0 to 50℃.

Claims

1. A high-sensitivity photonic crystal fiber dual-parameter sensor based on the SPR effect, comprising a substrate (1), a fiber core and a cladding disposed on the substrate (1), characterized in that, The cladding is symmetrically polished on both sides to form two symmetrical polishing surfaces, namely the upper polishing surface (8) and the lower polishing surface (11); the upper polishing surface (8) is provided with a plasma exciton material layer (9) and a titanium dioxide layer (10) in sequence, and the lower polishing surface (11) is provided with a silver film layer (12). A core air hole (4) is provided at the center of the base (1). In the cladding outside the core air hole (4), from the outside in, there are sequentially arranged outer layer air holes (2) in a hexagonal structure centered on the core air hole (4), intermediate layer air holes (3) in a hexagonal structure centered on the core air hole (4), and inner layer air holes arranged in a straight line. The center point of the outer layer air hole (2), the center point of the intermediate layer air hole (3), the center of the core air hole (4), and the center of the base (1) coincide. The outer air hole (2) includes 4 small air holes (7) and 10 large air holes (5), wherein the 4 small air holes (7) are symmetrically distributed along the X-axis and the 10 large air holes (5) are symmetrically distributed along the Y-axis. The small air holes (7) are located close to the core air hole (4) and the large air holes (5) are located outside the small air holes (7). The intermediate air hole (3) includes two medium air holes (6) and four large air holes (5), which are distributed on the vertices of the hexagon. The two medium air holes (6) are symmetrically distributed along the Y-axis and are located between the core air hole (4) and the upper polishing surface (8). The inner air vent includes two large air vents (5), which are located on the X-axis and symmetrically arranged on the left and right sides of the core air vent (4); The diameters of the small air hole (7), medium air hole (6) and large air hole (5) increase from small to large, and the diameter of the core air hole (4) is equal to that of the small air hole (7); In the outer layer air hole (2), the distance between the centers of any two adjacent air holes is equal; the distance between the centers of the two large air holes (5) constituting the inner layer air hole is equal to the distance between the centers of any two adjacent air holes in the outer layer air hole (2); the distribution of the three adjacent air holes in the middle layer air hole (3) and the inner layer air hole is in an equilateral triangular lattice structure; the distance between the centers of two adjacent air holes in the middle layer air hole (3) and the outer layer air hole (2) in the X-axis direction is equal to the distance between the centers of any two adjacent air holes in the outer layer air hole (2).

2. The high-sensitivity photonic crystal fiber dual-parameter sensor based on the SPR effect according to claim 1, characterized in that, The distance between the center of the substrate (1) and the upper polishing surface (8) or the lower polishing surface (11) is 7.0 ± 0.1 μm.

3. The high-sensitivity photonic crystal fiber dual-parameter sensor based on the SPR effect according to claim 1, characterized in that, The diameters of the core air hole (4) and the small air hole (7) are both 0.55±0.1μm, the diameter of the medium air hole (6) is 1.15±0.1μm, and the diameter of the large air hole (5) is 1.85±0.1μm.

4. The high-sensitivity photonic crystal fiber dual-parameter sensor based on the SPR effect according to claim 1, characterized in that, in In the outer air pore (2), the distance between the centers of any two adjacent air pores is 3.28±0.1μm; the distance between the centers of the two large air pores (5) that constitute the inner air pore is 3.28±0.1μm.

5. The high-sensitivity photonic crystal fiber dual-parameter sensor based on the SPR effect according to any one of claims 1 to 4, characterized in that, The span of the plasma exciton material layer (9) and the titanium dioxide layer (10) in the X-axis direction is 6.56±0.2μm.

6. The high-sensitivity photonic crystal fiber dual-parameter sensor based on the SPR effect according to claim 5, characterized in that, The thickness of the plasma exciton material layer (9) is 45-55 nm.

7. The high-sensitivity photonic crystal fiber dual-parameter sensor based on the SPR effect according to claim 5, characterized in that, The thickness of the titanium dioxide layer (10) is 50-60 nm.

8. The high-sensitivity photonic crystal fiber dual-parameter sensor based on the SPR effect according to any one of claims 1 to 4, characterized in that, The silver film layer (12) has a span of 6.56±0.2μm in the X-axis direction.

9. The high-sensitivity photonic crystal fiber dual-parameter sensor based on the SPR effect according to claim 8, characterized in that, The thickness of the silver film layer (12) is 35-45 nm.

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