Hyperbolic metamaterial refractive index sensor, detection method and application

Abstract

The invention relates to the technical field of hyperbolic metamaterial refractive index sensing, and particularly discloses two hyperbolic metamaterial refractive index sensors. One is a hyperbolic metamaterial refractive index sensor based on a BPP mode, the hyperbolic metamaterial refractive index sensor comprises a prism and a sensing detection assembly, the sensing detection assembly comprises a metal film and a metal nanometer cylinder array, and the metal film is coupled with the metal nanometer cylinder array. According to the other type, a regulation and control assembly is additionally arranged on the basis of the hyperbolic metamaterial refractive index sensor based on the BPP mode, and the surface of the metal nanometer cylinder is wrapped with graphene, so that the sensitivity of the hyperbolic metamaterial refractive index sensor can be electrically regulated and controlled. The two sensors provided by the invention both have relatively high sensitivity, and particularly, the electrically controllable hyperbolic metamaterial refractive index sensor can flexibly adjust an internal electric field by virtue of graphene and a control component, so that the detection sensitivity is further improved while different detection requirements are accurately met, and the detection sensitivity is further improved. The technical problem that the sensitivity of an existing sensor is generally low and cannot be regulated and controlled is solved.

Description

Technical Field

[0001] The present application relates to the technical field of hyperbolic metamaterial refractive index sensing, and in particular to a hyperbolic metamaterial refractive index sensor, a detection method and an application thereof. Background Art

[0002] Surface Plasmon Resonance (SPR) is a physical optical phenomenon that occurs at the interface between metal and dielectric. The excitation mechanism of this phenomenon lies in the interaction between light and free electrons on the metal surface. Specifically, when a light beam is incident on the surface of a metal film, the electromagnetic field component in the light beam will propagate between the metal film and the dielectric layer. In particular, when the wavelength of the incident light matches the oscillation frequency of free electrons on the metal surface, the free electrons propagate along the interface between the dielectric layer and the metal layer. In the field of sensors built based on the above-mentioned surface plasmon resonance principle, there are two classic plasma sensors, namely propagating surface plasmon resonance (PSPR) and localized surface plasmon resonance (LSPR) sensors.

[0003] However, at present, these sensors have certain limitations in terms of sensitivity, and their sensitivity is usually low. For example, the numerical simulation results of a D-type photonic crystal fiber SPR sensor proposed by Rifat et al. show that in the range of refractive index of 1.33~1.43, the maximum sensitivity of the sensor can reach 46000 nm / RIU; Lu Xiao et al. proposed a new near-field leakage-enhanced fiber surface plasmon resonance (NLF-SPR) sensor based on cuboid gold nanoarrays and WSe cooperative sensitization, and studied the modulation of the gold nanoarray structural parameters on the electric field distribution and spectral characteristics through three-dimensional finite element simulation. The refractive index is in the range of 1.3332~1.3432, and the sensitivity of the NLF-SPR sensor can reach up to 14692.46 nm / RIU. Compared with the demand for high-precision detection in practical applications, such sensitivity is obviously difficult to meet the requirements, especially in the scenario where it is necessary to accurately capture the slight changes in the refractive index of the medium in contact with the metal layer, the problem of insufficient accuracy of existing sensors becomes more and more prominent.

[0004] With the rapid development of nanofabrication technology, many high-performance metamaterial plasma sensors have emerged and have shown significant advantages over traditional surface plasmon resonance (SPR) sensors. Metamaterials are artificial synthetic materials with extremely unique electromagnetic properties. Among them, metamaterials that exhibit hyperbolic dispersion characteristics, such as 2D hyperbolic metasurfaces (HM) and 3D hyperbolic metamaterials (HHM), show excellent sensing performance. HHM has anisotropic optical properties and involves complex mode relationships. How to effectively excite the plasma-polariton (BPP) mode to achieve high-sensitivity sensing has become a key research topic at present. Summary of the invention

[0005] In view of this, the purpose of this application is to provide a hyperbolic metamaterial refractive index sensor and a detection method and application, which are used to solve the problems of low sensitivity of existing sensors, low anisotropic optical properties of metamaterials, and complex patterns.

[0006] In order to achieve the above technical objectives, the present application provides a hyperbolic metamaterial refractive index sensor based on the BPP mode, including a prism and a sensing detection component;

[0007] A sensing detection component is arranged on the surface of the prism; the sensing detection component comprises a metal film and a metal nano-cylinder array, and the metal film is coupled to the metal nano-cylinder array.

[0008] Furthermore, the thickness of the metal film is 10~30 nm.

[0009] Furthermore, the diameter of the metal nano-cylinder array is 80-120 nm, the height is 300-400 nm, and the spacing between the centers of adjacent metal nano-cylinders is 100-200 nm.

[0010] Furthermore, the material of the metal film is Au; the material of the metal nano-cylinder array is Au.

[0011] Furthermore, the refractive index of the prism is 1.5163, the width is 1~4 um, and the height is 3~6 um.

[0012] The present application provides a hyperbolic metamaterial refractive index sensor with electrically adjustable sensitivity, comprising a hyperbolic metamaterial refractive index sensor based on a BPP mode and a regulating component.

[0013] The surface of metal nanocylinders is coated with graphene;

[0014] The regulating component includes a glass micro flow channel, an ITO transparent conductive material, and a bias voltage arranged on the surface of the metal film;

[0015] The glass microfluidic cell is a rectangular structure with openings at least on two sides, one of which is in close contact with the surface of the metal film, and the metal nano-cylinder array with graphene wrapped on the surface is enclosed in the glass microfluidic cell; the other opening is used as an inflow channel for the object to be tested, so that the object to be tested can enter the glass microfluidic cell and contact the sensor detection component;

[0016] ITO transparent conductive material is laid on the surface of the glass microfluidic cell; the positive electrode of the bias voltage is arranged on the surface of the ITO transparent conductive material.

[0017] Furthermore, the thickness of graphene is 0.34~2.38 nm.

[0018] The present application provides a sensor detection method, comprising the following steps:

[0019] S1, placing the sensing detection component of the sensor in the object to be tested, so that the object to be tested flows into the opening of the glass microfluidic cell and contacts the sensing detection component;

[0020] S2, set the incident light to enter the sensor at an angle of 61.5~62°, draw a reflection spectrum curve according to the wavelength range of the reflected light, and finally calculate the refractive index of the substance to be tested.

[0021] The present application provides an application of a sensor for use in the field of gas or liquid detection.

[0022] Furthermore, it includes: monitoring the change of the refractive index of the solution during the chemical reaction; detecting the concentration of pollutants in the air or water; monitoring the change of the refractive index of the liquid in the organism and detecting biological molecules.

[0023] In summary, the present application provides a hyperbolic metamaterial refractive index sensor based on the BPP mode, including a prism and a sensing detection component; a sensor component composed of a metal film coupled to a metal nanocylinder array is arranged on the surface of the prism. The hyperbolic metamaterial refractive index sensor based on the BPP mode provided by the present application has a significant sensitivity performance advantage, and can achieve a sensitivity value of up to 58416.67 nm / RIU in the refractive index range of 1.333~1.3336.

[0024] The present application also provides a hyperbolic metamaterial refractive index sensor with electrically adjustable sensitivity, which adds an adjustment component to the hyperbolic metamaterial refractive index sensor based on the BPP mode, and wraps graphene on the surface of the metal nano-cylinder. Among them, the adjustment component includes a glass micro-flow cell, an ITO transparent conductive material, and a bias voltage arranged on the surface of the metal film; the ITO transparent conductive material is laid on the surface of the glass micro-flow cell; and the positive electrode of the bias voltage is arranged on the surface of the ITO transparent conductive material. The hyperbolic metamaterial refractive index sensor with electrically adjustable sensitivity provided in the present application innovatively adopts a unique construction method of coating the two-dimensional material graphene on the surface of the metal nano-cylinder array; at the same time, the Fermi level of graphene is precisely adjusted by means of an external bias voltage, thereby achieving the purpose of efficient adjustment of the sensitivity of the refractive index sensor. Specifically, within the energy level range of 0.38~0.78 eV, the sensor can achieve sensitive control changes from 23366.67~90116.67 nm / RIU. Compared with the mode using only metal nanocylinder arrays, its sensitivity is significantly improved by 31700nm / RIU. This is due to the unique electrical properties of graphene and its synergistic mechanism with metal nanocylinder arrays and various components, which has opened up a new path for the precise sensitivity control of refractive index sensors. Compared with the prior art, the two hyperbolic metamaterial refractive index sensors provided in this application have greatly improved the sensitivity of the refractive index sensors, solving the technical problem of the lack of highly sensitive refractive index sensors in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0026] Figure 1 A schematic diagram of the structure of a hyperbolic metamaterial refractive index sensor with electrically adjustable sensitivity configured on the basis of a plasma hyperbolic metamaterial refractive index sensor based on a BPP mode provided in an embodiment of the present application;

[0027] Figure 2 A top view of a plasma hyperbolic metamaterial refractive index sensor based on the BPP mode provided in Example 1 of the present application;

[0028] Figure 3 A characterization diagram of the relative dielectric constant of the plasma hyperbolic metamaterial refractive index sensor based on the BPP mode provided in Example 1 of the present application;

[0029] Figure 4A modal index matching diagram of the plasma hyperbolic metamaterial refractive index sensor based on the BPP mode provided in Example 1 of the present application;

[0030] Figure 5 A reflection spectrum curve diagram of the plasma hyperbolic metamaterial refractive index sensor based on the BPP mode provided in Example 1 of the present application under different BPP modes;

[0031] Figure 6 A simulation diagram of the xz plane two-dimensional electric field distribution of the electric field at the center position of the metal nano-cylinder array of the plasma hyperbolic metamaterial refractive index sensor based on the BPP mode provided in Example 1 of the present application under different BPP modes;

[0032] Figure 7 A reflection spectrum curve diagram of the plasma hyperbolic metamaterial refractive index sensor based on the BPP mode provided in Example 1 of the present application under different environmental refractive index conditions;

[0033] Figure 8 A reflection spectrum curve diagram of the hyperbolic metamaterial refractive index sensor with electrically adjustable sensitivity provided in Example 2 of the present application under different environmental refractive index conditions;

[0034] Fig. 9 A sensitivity comparison diagram of two hyperbolic metamaterial refractive index sensors provided in Examples 1 and 2 of the present application;

[0035] Fig.10 A sensitivity fitting curve diagram of the hyperbolic metamaterial refractive index sensor with electrically adjustable sensitivity provided in Example 2 of the present application;

[0036] Figure numerals: 1. prism; 2. incident light; 3. reflected light; 4. metal film; 5. metal nanocylinder array; 6. graphene; 7. glass microfluidic cell; 8. ITO transparent conductive material; 9. bias voltage. DETAILED DESCRIPTION

[0037] The technical solutions of the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the specification of the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection requested by the present application.

[0038] The sources of all raw materials in the present invention are not particularly limited and can be purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0039] The embodiment of the present invention provides a hyperbolic metamaterial refractive index sensor based on the BPP mode, including a prism and a sensing detection component;

[0040] A sensing detection component is arranged on the surface of the prism; the sensing detection component comprises a metal film and a metal nano-cylinder array, and the metal film is coupled to the metal nano-cylinder array.

[0041] In some embodiments, the thickness of the metal film is 10-30 nm.

[0042] In some embodiments, the diameter of the metal nano-cylinder array is 80-120 nm, the height is 300-400 nm, and the spacing between the centers of adjacent metal nano-cylinders is 100-200 nm.

[0043] In some embodiments, the material of the metal film is Au; the material of the metal nano-column array is Au.

[0044] In some embodiments, the prism has a refractive index of 1.5163, a width of 1-4 um, and a height of 3-6 um.

[0045] The embodiment of the present invention provides a hyperbolic metamaterial refractive index sensor with electrically adjustable sensitivity.

[0046] It includes a hyperbolic metamaterial refractive index sensor based on the BPP mode, a control component, and a metal nano-cylinder surface wrapped with graphene;

[0047] The regulating component includes a glass micro flow channel, an ITO transparent conductive material, and a bias voltage arranged on the surface of the metal film;

[0048] The glass microfluidic cell is a rectangular structure with openings at least on two sides, one of which is in close contact with the surface of the metal film, and the metal nano-cylinder array with graphene wrapped on the surface is enclosed in the glass microfluidic cell; the other opening is used as an inflow channel for the object to be tested, so that the object to be tested can enter the glass microfluidic cell and contact the sensor detection component;

[0049] ITO transparent conductive material is laid on the surface of the glass microfluidic cell; the positive electrode of the bias voltage is arranged on the surface of the ITO transparent conductive material.

[0050] In some embodiments, the graphene has a thickness of 0.34-2.38 nm.

[0051] An embodiment of the present invention provides a sensor detection method, comprising the following steps:

[0052] S1, placing the sensing detection component of the sensor in the object to be tested, so that the object to be tested flows into the opening of the glass microfluidic cell and contacts the sensing detection component;

[0053] S2, set the incident light to enter the sensor at an angle of 61.5~62°, draw a reflection spectrum curve according to the wavelength range of the reflected light, and finally calculate the refractive index of the substance to be tested.

[0054] The embodiment of the present application provides an application of a sensor for use in the field of gas or liquid detection.

[0055] Specifically, it includes monitoring the change of solution refractive index during chemical reaction; detecting the concentration of pollutants in air or water; monitoring the change of liquid refractive index in organisms and detecting biological molecules.

[0056] It should be noted that in the specific application scenario of using the sensor as a biological refractive index sensor, its detection principle is based on the interaction mechanism between biological molecules. When put into use, the key structure of the metal nanocylinder array will be used. Specifically, biological molecules with specific recognition functions such as proteins, nucleic acids or enzymes are attached in the tiny gaps between the metal nanocylinders. Once these biological molecules are attached, they will interact with the surrounding environment and the substances in the sensing detection component, thereby causing the original plasma resonance characteristics of the sensing detection component to change significantly. As a key factor in determining the optical response of the sensor, the change of the plasma resonance characteristics will further cause the reflection spectrum to change accordingly. By accurately capturing and analyzing the dynamic changes of these reflection spectra, it is possible to successfully determine whether biological molecules such as proteins, nucleic acids or enzymes exist in the test sample, thereby achieving high sensitivity and high specificity detection of specific biological molecules, providing strong technical support for many fields such as biomedical research and clinical diagnosis.

[0057] The applicant further provides the following reference specific embodiments to describe the present invention. It should be noted that these embodiments are merely illustrative and do not limit the present invention in any way.

[0058] Example 1

[0059] See also Figure 1~2 Embodiment 1 of the present application provides a plasma hyperbolic metamaterial refractive index sensor based on the BPP mode, including a prism 1 and a sensing detection component, wherein the sensing detection component is arranged on the surface of the prism; the sensing detection component includes a metal film 4 and a metal nano-cylinder array 5, and the metal film 4 is coupled to the metal nano-cylinder array 5.

[0060] The metal film 4 is a gold film with a thickness of 20 nm, the metal nano-cylinder array 5 is a gold nano-cylinder array, and the diameter of the gold nano-cylinder array 5 is 114.2 nm, the height is 365 nm, and the spacing P between the centers of adjacent gold nano-cylinders is x / P y 160 nm (see Figure 3 ).

[0061] Analysis 1, relative dielectric constant analysis

[0062] Hyperbolic metamaterials (HMMs) have anisotropic optical properties. In particular, they exhibit positive dielectric constants in one direction and negative dielectric constants in the other direction. This anisotropic property enables the sensor to detect small changes in the refractive index of the medium in contact with the metal layer with high sensitivity. However, this series of changes involves complex mode relationships, among which how to effectively excite the plasmon-polariton (BPP) mode to achieve high-sensitivity sensing is an important issue. This example is based on the refractive index sensor structure of the metal nanocylinder array, calculates the effective dielectric constant, and obtains the hyperbolic dispersion region of the proposed HMM structure, see Figure 3 . As can be seen from the figure, a strong body plasma-polariton mode is exhibited at λ ≥ 383 nm, and it works in the near-infrared wavelength region. The emergence of this mode not only means that the sensor can respond strongly to changes in the refractive index of the medium in this wavelength band, but also because it works in the near-infrared wavelength region, it is highly adapted to many practical application scenarios. For example: in the biomedical field, near-infrared light can effectively penetrate biological tissues, reduce scattering and absorption, so that the sensor can obtain more accurate signals when detecting changes in the refractive index of liquids or biological molecules in the body, and avoid excessive interference; in environmental monitoring, the low background noise characteristics of the near-infrared band help to improve the signal-to-noise ratio of the sensor, enhance the detection ability of pollutants in the air or impurities in water, and comprehensively improve the practical value of the sensor, providing strong technical support for the development of many cutting-edge fields.

[0063] Analysis 2, modal matching simulation curve analysis

[0064] This application simulates the hyperbolic metamaterial refractive index sensor to obtain the modal matching simulation curve. The sensor core consists of a prism and a sensor detection component, in which the sensor detection component plays a key role in achieving high-quality plasma-polariton (BPP) mode acquisition by coupling the negative refractive index hyperbolic metamaterial (NHMM) with the prism. Based on the precise phase matching requirements of the NHMM-excited BPP mode, a modal index matching diagram is drawn (see Figure 4 ), there are three intersection points in the near-infrared band, indicating that this band is theoretically possible to excite three BPP modes. Then, the rigorous coupled wave analysis (RCWA) method was used to simulate the reflection spectrum in all directions (see Figure 5 ), the results show that there are three resonance depressions in the simulated spectrum, corresponding to the BPP modes of q=1, q=2, and q=3 with resonance wavelengths from long to short, and the simulation results are highly consistent with the analysis results. The above results strongly verify the theoretical model and lay a solid foundation for the subsequent optimization, performance improvement and precise application of sensors in multiple fields.

[0065] Analysis 3, Reflectance Spectrum Analysis

[0066] In the refractive index sensor provided by the present application, when the incident light passes through the prism and enters the metal film at a specific incident angle, the photons interact with the electrons on the surface of the metal film, part of the photon energy is absorbed by the electrons, and a plasma resonance phenomenon occurs on the surface of the metal film. Electromagnetic waves can propagate on the surface of the metal film, and at the same time, the metal nanocylinder array on the metal film excites the plasma excitons. Draw a two-dimensional electric field distribution simulation diagram along the cross-sectional direction (xz plane) of the metal nanocylinder array, see Figure 6 . As can be seen from the figure, the electric field presents a unique distribution trend, which is confined between adjacent nanorods and moderately penetrates into the surrounding environment. In this situation, BPP modes of different orders are excited one after another, and show a significant rule: the smaller the order, the higher the corresponding electric field intensity. This correlation between electric field intensity and BPP mode order plays a vital role in deeply understanding the optical response characteristics of the sensor, accurately grasping the source of reflected light and its subsequent change trend, and provides a core theoretical basis for further drawing accurate reflected light curves.

[0067] In summary, the simulation process of the refractive index sensor provided in this application is as follows: when the incident light is incident obliquely through the prism-gold film-gold nanocylinder array, and the incident angle is close to the critical condition of attenuated total reflection, the evanescent field of the BPP mode is the strongest, and an obvious resonance dip appears in the reflection spectrum; then the rigorous coupled wave analysis (RCWA) method is used to simulate the reflection spectrum. Figure 5 , three resonance dips appeared in the simulated spectrum, corresponding to the BPP modes of q=1, q=2, and q=3 with resonance wavelengths from long to short. This result shows that the BPP mode is effectively excited. The simulation diagram of the two-dimensional electric field distribution in the xz plane at the center of the gold nanocylinder array is shown in Figure 6 As shown in the figure, the black frame surrounds the gold nanorod array and the gold film. It can be seen from the figure that the electric field is confined to the adjacent nanorods and penetrates into the environment, and different orders of BPP modes are excited. The smaller the order, the higher the electric field strength. Figures 5 and 6 It can be seen that the sensitivity of q=2 or 3 is relatively low, so the present application uses a metal nano-cylinder array with a higher sensitivity of q=1 order mode for sensitivity testing.

[0068] Detection 1, sensitivity detection

[0069] The refractive index sensor provided by the present application is used to test the sensitivity under different environmental refractive index conditions. When the environmental refractive index in this embodiment is 1.333, 1.3332, 1.3333, 1.3334 and 1.3336, the wavelength range of the light reflected by the sensor under this condition is within the range of 1400-2100 nm. A reflection spectrum is drawn based on the wavelength range of the above reflected light, as shown in FIG. Figure 7As shown in the figure, it can be seen that each different environmental refractive index tested in this application corresponds to a reflection spectrum curve, and the range of its resonance peak is concentrated in 1600~1800 nm, and with the increase of refractive index, the resonance peak shifts toward the long wavelength direction; when the environmental refractive index changes from 1.333 to 1.3336, the wavelength shift can reach 35.05 nm. Fig. 9 It can be seen from the sensitivity bar graph that the refractive index sensor provided by the present application has a sensitivity of up to 58416.67 nm / RIU. The above experimental results show that the plasma hyperbolic metamaterial refractive index sensor based on the BPP mode proposed in the present application, with the help of the synergistic effect of the prism and the sensing detection component, successfully and effectively excites the bulk plasma polaritons, thereby realizing the important function of high-sensitivity sensing. This high sensitivity characteristic enables the sensor to accurately monitor the slight changes in the refractive index of the medium in many fields such as chemical analysis and environmental pollution assessment, meeting the actual needs of related application scenarios for high-precision refractive index detection.

[0070] Example 2

[0071] See also Figure 2 , the embodiment of the present application provides a hyperbolic metamaterial refractive index sensor with electrically adjustable sensitivity;

[0072] On the basis of the plasma hyperbolic metamaterial refractive index sensor based on the BPP mode provided in Example 1, a control component is added, and graphene 6 is wrapped on the surface of the metal nano-cylinder; the control component includes a glass micro-flow channel 7, an ITO transparent conductive material 8, and a bias voltage 9 arranged on the surface of the metal film; the glass micro-flow channel 7 is a rectangular structure with openings on three sides, one of which is close to the surface of the metal film 4, and the metal nano-cylinder array 5 is included in the glass micro-flow channel; the other two openings are arranged oppositely, as the inflow channel of the object to be tested, so that the object to be tested enters the glass micro-flow channel 7 and contacts the sensing detection component; the ITO transparent conductive material 8 is laid on the surface of the glass micro-flow channel 7; and the positive electrode of the bias voltage 9 is arranged on the surface of the ITO transparent conductive material 8. Among them, the thickness of the graphene is 1.7 nm.

[0073] Detection 1, sensitivity detection:

[0074] The refractive index sensor provided by the present application is used to test the sensitivity under different environmental refractive index conditions. When the environmental refractive index in this embodiment is 1.333, 1.3332, 1.3333, 1.3334 and 1.3336, the reflection spectrum reflected by the sensor is plotted under this condition, as shown in FIG. Figure 8 As shown. Figure 8It can be seen that the different environmental refractive indices tested in this application correspond to a reflection spectrum curve, and the range of the resonance peak is concentrated in 1600~1800 nm, and with the increase of the refractive index, the resonance peak shifts toward the long wavelength direction. Compared with Example 1, when the environmental refractive index of this embodiment changes from 1.333 to 1.3336, the wavelength shift is 54.07 nm, and the wavelength shift is improved by 19.02 nm compared with Example 1, and the sensitivity of the refractive index sensor is as high as 90116.67 nm / RIU. At the same time, the sensitivity of the sensor is further tested by adjusting the bias voltage to change the Fermi level of graphene, such as Fig. 9 As shown. It can be seen from the figure that when the Fermi level of graphene gradually increases from 0.38 eV to 0.58 eV, the sensitivity of the refractive index sensor shows a corresponding upward trend; however, after the Fermi level exceeds 0.58 eV, as the Fermi level continues to increase, the sensitivity of the refractive index sensor gradually decreases. In the Fermi level range of 0.38~0.78 eV, the refractive index sensor successfully achieved a sensitivity regulation change from 23366.67~90116.67 nm / RIU. Among them, the maximum sensitivity of the refractive index sensor is significantly improved by 31700 nm / RIU compared with Example 1. This achievement effectively solves the key technical problem of the lack of high-sensitivity refractive index sensors faced in the prior art field, and successfully achieves a large-range and high-precision regulation effect on the sensitivity of the refractive index sensor, greatly expanding the applicability and practicality of this type of sensor in different application scenarios. In addition, a linear fitting analysis was performed on the resonance peak wavelength position of the refractive index sensor obtained under the regulation of graphene at different Fermi levels and the ambient refractive index. Fig.10 It can be clearly seen that the data points show good linear distribution characteristics, which fully demonstrates that the results obtained in this simulation experiment are highly reliable and accurate, and provides a solid data foundation and theoretical basis for further in-depth research and optimization of the performance of the refractive index sensor. It is expected to promote the widespread application and rapid development of related technologies in optical sensing, biomedical testing, environmental monitoring and other fields.

[0075] The above are only preferred embodiments of the present application and are not intended to limit the present invention. Although the present application has been described in detail with reference to the examples, those skilled in the art can still modify the technical solutions recorded in the aforementioned examples or make equivalent substitutions for some of the technical features therein. However, any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A hyperbolic metamaterial refractive index sensor based on BPP mode, characterized in that: Including prism, sensor detection components; The sensing detection component is arranged on the surface of the prism; The sensing detection component includes a metal film and a metal nano-cylinder array, and the metal film is coupled to the metal nano-cylinder array.

2. The hyperbolic metamaterial refractive index sensor based on the BPP mode according to claim 1, characterized in that: The thickness of the metal film is 10-30 nm.

3. The hyperbolic metamaterial refractive index sensor based on the BPP mode according to claim 1, characterized in that: The diameter of the metal nano-cylinder array is 80-120 nm, the height is 300-400 nm, and the spacing between the centers of adjacent metal nano-cylinders is 100-200 nm.

4. The hyperbolic metamaterial refractive index sensor based on the BPP mode according to claim 1, characterized in that: The material of the metal film is Au; the material of the metal nano-column array is Au.

5. The hyperbolic metamaterial refractive index sensor based on the BPP mode according to claim 1, characterized in that: The refractive index of the prism is 1.5163, the width is 1-4 um, and the height is 3-6 um.

6. A hyperbolic metamaterial refractive index sensor with electrically adjustable sensitivity, characterized in that: The invention comprises a hyperbolic metamaterial refractive index sensor based on the BPP mode and a control component as described in any one of claims 1 to 5, The surface of the metal nano-cylinder is coated with graphene; The regulating component includes a glass micro flow channel, an ITO transparent conductive material, and a bias voltage arranged on the surface of the metal film; The glass microfluidic cell is a rectangular structure with openings at least on two sides, wherein one opening is in close contact with the surface of the metal film, and the metal nano-cylinder array with graphene wrapped on the surface is included in the glass microfluidic cell; the other opening serves as an inflow channel for the object to be tested, so that the object to be tested can enter the glass microfluidic cell and contact the sensing detection component; The ITO transparent conductive material is laid on the surface of the glass microfluidic channel; the positive electrode of the bias voltage is arranged on the surface of the ITO transparent conductive material.

7. The hyperbolic metamaterial refractive index sensor with electrically adjustable sensitivity according to claim 6, characterized in that: The thickness of the graphene is 0.34-2.38 nm.

8. A detection method using the sensor according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, placing the sensing detection component of the sensor in the object to be tested, so that the object to be tested flows into the opening of the glass microfluidic cell and contacts the sensing detection component; S2, set the incident light to enter the sensor at an angle of 61.5~62°, draw a reflection spectrum curve according to the wavelength range of the reflected light, and finally calculate the refractive index of the substance to be tested.

9. An application of the sensor according to any one of claims 1 to 7, characterized in that: Used in gas or liquid detection fields.

10. Use of the sensor according to claim 9, characterized in that: include: Monitor the change of solution refractive index during chemical reaction; detect the concentration of pollutants in air or water; monitor the change of liquid refractive index in organisms and detect biological molecules.

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