Ultrahigh-sensitivity terahertz antibiotic sensor based on petal structure

Abstract

The invention provides a petal structure-based ultra-high sensitivity terahertz antibiotic sensor. The petal structure-based ultra-high sensitivity terahertz antibiotic sensor comprises at least one sensing unit arranged in an array, each sensing unit comprises a graphene layer and a dielectric layer from top to bottom, two same resonators are formed on the graphene layer, each resonator is designed to be of a petal structure comprising an inner ring and the inner ring, the two resonator structures are arranged in a staggered mode, and through the unique petal structure design and the combination of the unique electronic characteristics and the EIT effect of the graphene material, the performance of the sensor is improved. The problem that a traditional EIT sensor is insufficient in detection precision under the condition of high sensitivity is solved.

Description

Technical Field

[0001] The present invention relates to the field of terahertz sensing technology, and particularly to an ultra-high sensitivity terahertz antibiotic sensor based on a petal structure. Background Art

[0002] Terahertz waves lie between microwaves and infrared light, with unique penetrability and non-ionizing characteristics, enabling them to exhibit great application potential in fields such as biomedical detection, environmental monitoring, security inspection, and communication. Especially in biomolecular detection, terahertz technology can achieve precise detection of trace substances by identifying the characteristic absorption peaks of molecules. The electromagnetically induced transparency (EIT) effect is a quantum interference phenomenon generated through the interaction of electromagnetic waves, initially discovered in atomic systems, manifested as a narrow transparent window appearing in the absorption spectrum, accompanied by a significant enhancement in dispersion. In recent years, the EIT effect has shown extensive application potential in fields such as optical sensing, optical switches, and quantum information processing. By introducing the EIT effect into the design of metamaterials, researchers can achieve precise regulation of electromagnetic waves, thereby enhancing the sensitivity and selectivity of sensors.

[0003] However, traditional EIT sensors face the following defects: 1. Dilemma of balancing sensitivity and Q value: When existing terahertz sensors pursue high sensitivity, the detection accuracy often decreases. Especially in the detection of trace substances, it is difficult to effectively balance high sensitivity and high quality factor (Q value). Specifically for EIT sensors, the Q value under high-sensitivity conditions often decreases, resulting in insufficient detection accuracy, which has become a key technical challenge in the research of EIT sensors. For example, due to structural design limitations, the number of passbands and frequency range of some existing multi-band filters are relatively fixed and lack reconfigurability. Although some studies have introduced active components such as varactor diodes to regulate the frequency, the frequency reconfiguration ability of existing technologies is still limited and difficult to meet the requirements of multi-frequency signal processing in complex communication environments.

[0004] 2. Fixed structure and lack of tunability: The structures of traditional EIT sensors usually use metal or dielectric materials, with relatively fixed designs and difficult to achieve dynamic regulation, which limits their application in complex environments.

[0005] 3. Material limitation problem: The structures of traditional EIT sensors usually use metal or dielectric materials, which have large losses in the terahertz band, further affecting the performance of the sensors. Summary of the Invention

[0006] The object of the present invention is to provide an ultra-high sensitivity terahertz antibiotic sensor based on a petal structure. By means of a unique petal structure design and in combination with the unique electronic properties of graphene materials and the EIT effect, the problem of insufficient detection accuracy of traditional EIT sensors under high-sensitivity conditions is solved.

[0007] To achieve the above object, the present technical solution provides an ultra-high sensitivity terahertz antibiotic sensor based on a petal structure, comprising: At least one array-arranged sensing unit; Each sensing unit includes a graphene layer and a dielectric layer from top to bottom. Two identical resonators are formed on the graphene layer, and each resonator is designed to include an inner ring and a petal structure of the inner ring. The two resonator structures are arranged in a staggered manner.

[0008] Compared with the prior art, the present technical solution has the following characteristics and beneficial effects: The ultra-high sensitivity terahertz antibiotic sensor based on a petal structure provided by the present solution can achieve a balance between high sensitivity and high Q value. The present invention significantly enhances the electric field intensity through the design of the petal structure and realizes the EIT effect through near-field coupling, resulting in a sharp EIT window formed by the sensor at 1.0 THz, with a window linewidth of only 0.05 THz. This design enables the sensor to maintain a high sensitivity (1.225 THz / RIU) while achieving a Q value of 20.8, solving the problem of the Q value decline of traditional EIT sensors under high-sensitivity conditions. Moreover, the ultra-high sensitivity terahertz antibiotic sensor based on a petal structure provided by the present solution exhibits excellent sensing performance under both vertical polarization and horizontal polarization conditions, can effectively separate signals and select frequencies, and is suitable for the detection of antibiotic molecules in complex environments.

[0009] Furthermore, the ultra-high sensitivity terahertz antibiotic sensor based on a petal structure provided by the present solution can also detect and process signals at different frequencies, is suitable for the multi-frequency signal processing requirements in complex environments, and can achieve dynamic regulation by adjusting the Fermi level of graphene, making it suitable for multi-channel communication systems or application scenarios that need to process multi-frequency signals. This multi-frequency signal processing ability enables the sensor to have broad application prospects in biomedical detection, environmental monitoring, and communication systems. Description of the Drawings

[0010] Figure 1 is a schematic diagram of the unit structure of an ultra-high sensitivity terahertz antibiotic sensor based on a petal structure designed by the present invention.

[0011] Figure 2 is a schematic diagram of the array layout of an ultra-high sensitivity terahertz antibiotic sensor based on a petal structure designed by the present invention.

[0012] Figure 3 It is a schematic diagram for analyzing the EIT mechanism of a super-high-sensitivity terahertz antibiotic sensor based on a petal structure designed by the present invention.

[0013] Figure 4 It is an electric field diagram at the resonant frequency of a super-high-sensitivity terahertz antibiotic sensor based on a petal structure designed by the present invention.

[0014] Figure 5 It is a transmission curve graph of a super-high-sensitivity terahertz antibiotic sensor based on a petal structure designed by the present invention under different polarization directions.

[0015] Figure 6 It is a graph showing the influence of the dielectric plate thickness d on the transparent window of a super-high-sensitivity terahertz antibiotic sensor based on a petal structure designed by the present invention.

[0016] Figure 7 It is a graph showing the influence of the coupling distance s on the transparent window of a super-high-sensitivity terahertz antibiotic sensor based on a petal structure designed by the present invention.

[0017] Figure 8 It is a transmission curve graph generated by the change of the Fermi level of a super-high-sensitivity terahertz antibiotic sensor based on a petal structure designed by the present invention.

[0018] Figure 9 It is a window frequency graph corresponding to different Fermi levels of a super-high-sensitivity terahertz antibiotic sensor based on a petal structure designed by the present invention.

[0019] Figure 10 It is a transmission curve graph corresponding to different refractive indices under x polarization of a super-high-sensitivity terahertz antibiotic sensor based on a petal structure designed by the present invention.

[0020] Figure 11 It is a window frequency graph corresponding to different refractive indices under x polarization of a super-high-sensitivity terahertz antibiotic sensor based on a petal structure designed by the present invention.

[0021] Figure 12 It is a transmission curve graph corresponding to different refractive indices under y polarization of a super-high-sensitivity terahertz antibiotic sensor based on a petal structure designed by the present invention.

[0022] Figure 13 It is a window frequency graph corresponding to different refractive indices under y polarization of a super-high-sensitivity terahertz antibiotic sensor based on a petal structure designed by the present invention. Detailed implementation manners

[0023] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0024] Those skilled in the art should understand that in the disclosure of the present invention, the orientation or positional relationships indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting the present invention.

[0025] Embodiment 1 As Figure 1 shown, this solution provides a super-high-sensitivity terahertz antibiotic sensor based on a petal structure, including: At least an array of sensing units; Each sensing unit includes a graphene layer and a dielectric layer from top to bottom. Two identical resonators are formed on the graphene layer, and each resonator is designed to include an inner ring and a petal structure of the inner ring. The two resonator structures are staggered.

[0026] The two petal-structured resonators on each sensing unit of this solution constitute the resonant part, and the two identical resonators can generate a symmetric electromagnetic field distribution at a specific frequency, forming a sharp EIT window through frequency detuning and phase interference. If only a single resonator is used, the energy level transition and coupling effect required for the transparent window cannot be achieved.

[0027] In some embodiments, the central positions of the inner ring and the outer ring in each resonator overlap and are spaced apart. In other words, the inner ring and the outer ring in each resonator of this solution are arranged in the form of concentric rings.

[0028] In some embodiments, the inner ring and the outer ring have the same shape.

[0029] In some embodiments, the inner ring is a closed loop formed by connecting at least two curved segments end to end, and the bending radian of each curved segment is the same. A concave point on the inner ring is formed at the connection between adjacent curved segments. Similarly, the outer ring is also a closed loop formed by connecting at least two curved segments end to end, and the bending radian of each curved segment is the same. A concave point on the outer ring is formed at the connection between adjacent curved segments.

[0030] Specifically, each bent segment on the inner ring is an arc segment that bulges outward relative to the center of the inner ring, and the center of the arc of the bent segment does not overlap with the center of the inner ring. This setting method enables each bent segment to form a petal leaf of the inner ring. Similarly, each bent segment on the outer ring is an arc segment that bulges outward relative to the center of the outer ring, and the center of the arc of the bent segment does not overlap with the center of the outer ring.

[0031] Furthermore, each bent segment on the inner ring corresponds one-to-one with each bent segment on the outer ring, that is, the center of the arc of each bent segment on the inner ring, the center of the arc of the outer ring, and the center of the resonator are located in the same radial direction.

[0032] That is, the inner ring in each resonator of this solution is a small petal pattern, the outer ring is a large petal pattern, each bent segment on the inner ring forms a petal leaf of the inner ring, and each bent segment on the outer ring forms a petal leaf of the outer ring.

[0033] In some specific embodiments, 4 bent segments are provided on the inner ring, and 4 bent segments are also provided on the outer ring, and the 4 bent segments are arranged in a one-to-one correspondence.

[0034] In a specific embodiment, the maximum distance R2 from the bent segment on the outer ring to the center of the outer ring on the same resonator is 17 μm, and the minimum distance r2 from the bent segment on the outer ring to the center of the outer ring is 11 μm, that is, the distance r2 from the concave point on the bent segment on the outer ring to the center of the outer ring is 11 μm. At the same time, the maximum distance R1 from the bent segment on the inner ring to the center of the inner ring is 7.5 μm, and the minimum distance r1 from the bent segment on the inner ring to the center of the inner ring is 4.8 μm, that is, the distance r1 from the concave point on the bent segment on the inner ring to the center of the inner ring is 4.8 μm. The advantage of this setting is that sharp petal concave points can be formed on the inner ring, so that the electric field at the concave point position can be greatly enhanced. Generally speaking, the sharper the concave point, the more significant the electric field local enhancement effect, thereby improving the resonance intensity and Q value; at the same time, the outer ring and the inner ring are spaced apart to ensure that the outer ring can form an effective near-field coupling with the inner ring, while avoiding excessive overlap of the electromagnetic field distribution and causing resonance frequency shift.

[0035] It should be noted that the dielectric layer is a quartz dielectric plate made of quartz material, and the relative dielectric constant of the quartz dielectric plate is 1.9. In a specific embodiment, the dielectric layer is in the shape of a square with equal length and width, and the length and width of the dielectric layer are both 72 μm. The advantage of this setting is that it can suppress the mutual interference between adjacent resonators. If the side length of the quartz dielectric plate is too small, the electromagnetic fields of adjacent units will interfere with each other and destroy the EIT effect; if the side length of the quartz dielectric plate is too large, the sensor integration will also be reduced.

[0036] In some embodiments, the thickness d of the dielectric layer is 5 - 12 μm. Preferably, the thickness d of the dielectric layer is 10 μm. When the thickness d of the dielectric layer = 10 μm, the bandwidth is compressed to 0.05 THz (Q = 20.8), meeting the requirements of high-precision detection. The decrease in transmittance is controllable, and the performance is better than that when d = 12 μm. The redshift of the peak frequency is moderate and matches well with the 1.0 THz fingerprint peak of chlortetracycline. This value is the core parameter optimized by simulation, ensuring the best balance between the sensitivity (1.225 THz / RIU) and the detection accuracy (Q = 20.8) of the sensor.

[0037] In some embodiments, the thickness of the graphene layer is 0.001 μm, that is, the thickness of the two resonators is 0.001 μm.

[0038] In addition, the two resonators on each sensing unit of this solution are arranged adjacent to each other and there is a gap between the two resonators. Specifically, in some embodiments, the connection line of the resonance centers of the two resonators is inclined with respect to the dielectric layer, that is, one resonator is located in the inclined direction of the other resonator.

[0039] In a specific embodiment, the minimum distance w between the two resonators is 2 μm. The advantage of this setting is that it can optimize the current path. The width of 2 μm can support the efficient transmission of high-frequency current on the graphene surface, while avoiding the electric field dispersion caused by being too wide.

[0040] Specifically, the two resonators are respectively located at the diagonal positions of the dielectric layer. It can be that one resonator is arranged at the lower left corner of the dielectric layer and the other resonator is arranged at the upper right corner of the dielectric layer; or one resonator is arranged at the upper left corner of the dielectric layer and the other resonator is arranged at the lower right corner of the dielectric layer, and the shortest distance between the two resonators is 2 μm. Specifically, each resonator is provided with four identical bending segments, and the distance between the bending segment above one resonator and the bending segment below the other resonator is the shortest distance between the two resonators.

[0041] In some embodiments, the coupling distance s between the two resonators is 2 - 5 μm. It should be noted that the coupling distance between the resonators refers to the minimum distance between the two resonators.

[0042] Preferably, the coupling distance s is 2.98. The advantage of this setting is that the electric field overlap region between the two resonators is maximized at this time to achieve strong coupling. When the coupling distance s > 5 μm, the coupling effect is significantly weakened, and the transmittance of the EIT window decreases. If the coupling distance s < 2 μm, it may cause stray capacitance interference.

[0043] As described above, the resonator on the ultra-high sensitivity terahertz antibiotic sensor based on the petal structure designed in this solution is designed as a double-petal structure. The petal-shaped resonator can concentrate the electromagnetic field energy at the concave points of the petals through its unique geometric structure, significantly enhancing the local electric field intensity. This design not only improves the sensitivity of the sensor but also realizes the energy level transition from the ground state to the transparent state through the near-field coupling effect, forming a sharp EIT window.

[0044] In addition, the two bright-mode resonators of the ultra-high sensitivity terahertz antibiotic sensor based on the petal structure provided in this solution generate strong interactions under the incidence of electromagnetic waves, forming two sharp transmission valleys and a sharp narrowband transmission window between the two valleys, with a peak frequency of 1.0 THz. Therefore, it can be used for the specific detection of chlortetracycline.

[0045] Specifically, the two petal-structured resonators can respectively generate bright-mode resonances (high radiation loss states) under the excitation of electromagnetic waves. When the two resonators are close to each other, the electric fields formed by the two resonators overlap in the gap region, forming near-field coupling. At the same time, through the interaction of electromagnetic fields with opposite phases, the radiation loss is canceled, forming a low-damping transparent state (EIT window). A single resonator corresponds to the ground state (loss state). After the coupling of the two resonators, the sensor can be made to transition from the ground state to the transparent state (low loss state). This process is achieved through resonance frequency detuning (0.99 THz and 1.02 THz) and phase interference, and finally a sharp transmission peak is generated at 1.0 THz.

[0046] In addition, since a graphene layer is used in the ultra-high sensitivity terahertz antibiotic sensor based on the petal structure provided in this solution, the peak frequency can be redshifted by adjusting the Fermi level of graphene. In other words, when the structure is fixed and the Fermi level of graphene is 0.3 eV, the peak frequency is determined to be 1.0 THz. When the Fermi level is adjusted (0.3 - 0.7 eV), the peak frequency can be redshifted, realizing frequency modulation in the range of 0.51 - 1.0 THz. However, the optimal sensing performance is still concentrated near 1.0 THz. Furthermore, different characteristic peaks can be detected by adjusting different Fermi levels.

[0047] In other words, the ultra-high sensitivity terahertz antibiotic sensor based on the petal structure of this solution can achieve frequency modulation within 0.51 - 1.0 THz. When the modulation results in a peak at 1.0 THz, it can be used to detect chlortetracycline.

[0048] In some embodiments, the ultra-high sensitivity terahertz antibiotic sensor based on the petal structure includes a plurality of sensing units arranged in an array, such as Figure 2 shown Figure 2The petal-structure-based ultra-high sensitivity terahertz antibiotic sensor in

[0049] Embodiment 2 To study and verify the performance of the petal-structure-based ultra-high sensitivity terahertz antibiotic sensor designed in this solution, this solution sets up a simulation environment for performance testing: The simulation environment is as follows: Electromagnetic simulation is carried out in the 0.3 - 1.2 THz frequency band using CST Microwave Studio finite element method software. The Fermi level of graphene is regulated by externally adjusting the bias voltage between the metal gate and the quartz substrate. The electromagnetic wave is a plane wave incident vertically in the -z direction. The boundary conditions are set as unit in the x and y directions and open in the z direction. The ambient temperature is 300K.

[0050] Parameter design of the petal-structure-based ultra-high sensitivity terahertz antibiotic sensor: For each sensing unit, the maximum distance R2 from the bent segment on the outer ring of the resonator to the center of the outer ring is 17 μm, and the minimum distance r2 from the bent segment on the outer ring to the center of the outer ring is 11 μm; the maximum distance R1 from the bent segment on the inner ring to the center of the inner ring is 7.5 μm, and the minimum distance r1 from the bent segment on the inner ring to the center of the inner ring is 4.8 μm; the side length Px of the dielectric plate along the x direction and the side length Py along the y direction are 72 μm, the width w of the resonant pattern is 2 μm, the thickness of the dielectric plate is d, the thickness of the graphene layer is 0.001 μm, the resonant distance is s, and the thickness of the dielectric layer is d.

[0051] (1) Simulation design of the EIT effect: To study the physical mechanism of the petal-structure-based ultra-high sensitivity terahertz antibiotic sensor, the thickness d of the dielectric layer is set to 10 μm and the resonant distance s is set to 2.95 μm. This invention conducts simulation calculations through the finite-difference time-domain method. The simulation is divided into three cases: (i) only the upper-right petal-shaped graphene resonant ring, (ii) only the lower-left petal-shaped graphene resonant ring, and (iii) the complete structure. The simulation results are as shown in Figure 3 and Figure 4 shown. Figure 3 is a schematic diagram for the analysis of the EIT mechanism of a petal-structure-based ultra-high sensitivity terahertz antibiotic sensor designed by this invention. By comparing the transmission spectra of the three simulation cases (i), (ii), and (iii), the mechanism of the formation of the EIT window by the coupling of the double resonators (a narrowband transparent window appears between the two transmission valleys) is demonstrated. Figure 4It is the electric field diagram at the resonant frequency of a ultra-high sensitivity terahertz antibiotic sensor based on petal structure designed by the present invention. It can be seen from the simulation results that (iii) the two bright-mode resonators in the complete structure produce strong interaction under the incidence of electromagnetic waves, forming two sharp transmission valleys, and a sharp narrow-band transmission window is formed between the two valleys, with the peak frequency of 1.0 THz.

[0052] Specifically, in terms of the mechanism of the EIT window, the present invention forms a sharp EIT window at 1.0 THz through the near-field coupling effect of two bright-mode resonators. The formation mechanism of the EIT window is based on the quantum interference effect. The electromagnetic transmission between the two resonators is coupled to the low-damping modes with opposite phases, restoring resonance and offsetting losses, thus generating a narrow-band transparent window in the absorption spectrum. This EIT effect not only improves the sensitivity of the sensor, but also enhances the dispersion characteristics, which is suitable for high-precision sensing applications. The generation of the EIT effect enables the sensor to achieve high transmittance at a specific frequency, while enhancing the dispersion characteristics. The formation of this EIT window is achieved through the design of the petal structure. Compared with the traditional circular ring structure, the petal-shaped resonator can concentrate the energy at the concave points of the petals, significantly enhancing the electric field intensity, thus generating a strong near-field coupling effect.

[0053] (2) Influence of the thickness d of the dielectric layer on the transparent window By setting the thickness d of the dielectric layer to be 5μm, 7μm, 10μm and 12μm respectively, the resonant distance s to be 2.95μm, and performing simulation tests on the transparent window of the ultra-high sensitivity terahertz antibiotic sensor based on the petal structure, the resulting diagrams are as Figure 6 shown. It can be seen that as the thickness d of the dielectric layer increases, the window peak undergoes a red shift, the window bandwidth decreases, and the transmittance decreases slightly. This is because the increase in the thickness of the dielectric layer provides space for multiple reflections and interference of the incident electromagnetic waves within the metamaterial structure, generating a canceling effect, and finally generating a transparent window with a narrower line width.

[0054] (3) Influence of the coupling distance on the transparent window By setting the coupling distance s to be 2.95μm, 5.7μm, 7.1μm, 8.4μm, 9.6μm respectively, and performing simulation tests on the transparent window of the ultra-high sensitivity terahertz antibiotic sensor based on the petal structure, the resulting diagrams are as Figure 7 shown. It can be seen that as the coupling distance s increases, the coupling effect between the two bright-mode resonators is weakened, thus reducing the transmittance of the window. The performance is optimal when the coupling distance s is 2.95μm.

[0055] (4) Fermi level regulation By adjusting the Fermi level of graphene to 0.3 eV, 0.4 eV, 0.5 eV, 0.6 eV, and 0.7 eV respectively, and performing simulation tests on the transparent window of the ultra-high-sensitivity terahertz antibiotic sensor based on the petal structure, the transmission curve generated by the change of the Fermi level is obtained as shown in Figure 8 shown, and the window frequency diagram corresponding to different Fermi levels is as shown in Figure 9 shown. It can be seen that the present invention realizes the dynamic regulation of the sensor. The Fermi level of graphene can be adjusted by an external bias voltage, thereby controlling the surface conductivity of the sensor and realizing the dynamic switching of the EIT window; when the Fermi level is 0.3 eV, the transparent window is in the "open" state; when the Fermi level increases to 0.7 eV, the EIT window is destroyed and the transparent window is in the "closed" state.

[0056] According to the definition of the frequency modulation depth MD, the maximum modulation depth that can be achieved by the ultra-high-sensitivity terahertz antibiotic sensor based on the petal structure is 43%, and the picosecond-level response time of the graphene material can quickly complete optical modulation.

[0057] (5)Test of polarization-insensitive characteristics: Set the thickness d of the dielectric layer to 10 μm and the resonant distance s to 2.95 μm. The test results of the polarization test of the ultra-high-sensitivity terahertz antibiotic sensor based on the petal structure in different directions are as shown in Figure 5 shown. It can be seen that the sensor shows the same transmission curve in the x-polarization and y-polarization directions, indicating its polarization-insensitive characteristics. This characteristic enables the sensor to work stably in complex environments and is suitable for a variety of application scenarios. Traditional EIT sensors often show different sensing performances in different polarization directions, which limits their applications in complex environments. However, through the design of the petal structure in the present invention, the polarization-insensitive characteristics are realized, so that the sensor shows stable sensing performances under both vertical polarization and horizontal polarization conditions. The sensitivity is as high as 1.225 THz / RIU, and the Q value is 20.8. Compared with the prior art, the sensor designed in the present invention has a high sensitivity while the Q value also reaches a relatively high level, significantly improving the sensing performance.

[0058] (6)Tests of different refractive indices: Set the thickness d of the dielectric layer to 10 μm and the resonant distance s to 2.95 μm. Polarization tests are performed on samples with refractive indices of 1.0, 1.1, 1.2, 1.3, and 1.4 in different directions, and the transmission curve diagrams corresponding to different refractive indices under x-polarization of the ultra-high-sensitivity terahertz antibiotic sensor based on the petal structure are as shown in Figure 10 shown, and the window frequency diagrams corresponding to different refractive indices under x-polarization of the ultra-high-sensitivity terahertz antibiotic sensor based on the petal structure are as shown in Figure 11As shown, the transmission curves corresponding to different refractive indices under y-polarization are as follows Figure 12 As shown, the window frequency diagrams corresponding to different refractive indices under y-polarization are as follows Figure 13 As shown.

[0059] Figure 10 For the transmission spectra corresponding to different refractive indices (n = 1.0 - 1.4) in the x-polarization direction, from Figure 10 it can be seen that when the refractive index increases, the EIT window frequency redshifts from 1.0 THz to 0.51 THz, verifying the sensitivity of the sensor to refractive index changes. The sensitivity calculated by the slope is 1.225 THz / RIU.

[0060] Figure 11 For the linear relationship diagram between the window frequency and the refractive index in the x-polarization, from Figure 11 it can be seen that when the frequency changes linearly with the refractive index, it proves the linear response characteristic and high sensitivity of the sensor. Figure 12 For the transmission spectra corresponding to different refractive indices in the y-polarization direction, from Figure 12 it can be seen that, similar to the x-polarization, the window frequency shifts from 1.0 THz to 0.53 THz, verifying the stability of the sensor under different polarization directions. The calculated sensitivity result is close to 1.225 THz / RIU, indicating polarization insensitivity. Figure 13 For the linear relationship diagram between the window frequency and the refractive index in the y-polarization, from Figure 13 it can be seen that it is consistent with the x-polarization result, further proving the polarization independence and reliability of the sensor.

[0061] In summary, the ultra-high-sensitivity terahertz antibiotic sensor based on the petal structure provided by this solution can achieve the balance of high sensitivity and high Q value, significantly enhancing the sensitivity of the sensor while maintaining a high Q value, solving the problem of insufficient detection accuracy of traditional EIT sensors under high-sensitivity conditions; it can have dynamic tunability: by adjusting the Fermi level of graphene, dynamic regulation of the sensor is achieved, and the maximum modulation depth can reach 43%; it can have polarization-insensitive characteristics: the sensor shows stable sensing performance under different polarization directions and is suitable for applications in complex environments.

[0062] Those skilled in the art should understand that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combinations of these technical features do not conflict, they should all be considered to be within the scope described in this specification.

[0063] The above embodiments only represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A super-high-sensitivity terahertz antibiotic sensor based on a petal structure, characterized in that, Comprising: At least an array of sensing units; Each sensing unit includes a graphene layer and a dielectric layer from top to bottom, wherein two identical resonators are formed on the graphene layer, and each resonator is designed to include an inner ring and a petal structure of the inner ring, and the two resonator structures are arranged in a staggered manner.

2. The super-high-sensitivity terahertz antibiotic sensor based on a petal structure according to claim 1, characterized in that, The central positions of the inner ring and the outer ring in each resonator overlap and are spaced apart, and the inner ring and the outer ring have the same shape.

3. The super-high-sensitivity terahertz antibiotic sensor based on a petal structure according to claim 2, characterized in that, The inner ring is a closed loop formed by connecting at least two curved segments end to end, and the bending radian of each curved segment is the same, and a concave point on the inner ring is formed at the connection between adjacent curved segments; the outer ring is also a closed loop formed by connecting at least two curved segments end to end, and the bending radian of each curved segment is the same, and a concave point on the outer ring is formed at the connection between adjacent curved segments.

4. The super-high-sensitivity terahertz antibiotic sensor based on a petal structure according to claim 1, characterized in that, Each curved segment on the inner ring is an arc segment protruding outward relative to the center of the inner ring, and the center of the arc of the curved segment does not overlap with the center of the inner ring; each curved segment on the outer ring is an arc segment protruding outward relative to the center of the outer ring, and the center of the arc of the curved segment does not overlap with the center of the outer ring.

5. The super-high-sensitivity terahertz antibiotic sensor based on a petal structure according to claim 1, characterized in that, Each curved segment on the inner ring corresponds one by one to each curved segment on the outer ring.

6. The super-high-sensitivity terahertz antibiotic sensor based on a petal structure according to claim 1, characterized in that, The maximum distance R2 from the curved segment on the outer ring to the center of the outer ring on the same resonator is 17 μm, the distance r2 from the curved segment on the outer ring to the center of the outer ring is 11 μm, the maximum distance R1 from the curved segment on the inner ring to the center of the inner ring is 7.5 μm, and the distance r1 from the curved segment on the inner ring to the center of the inner ring is 4.8 μm.

7. The super-high-sensitivity terahertz antibiotic sensor based on a petal structure according to claim 1, characterized in that, The dielectric layer is a quartz dielectric plate made of quartz material, the relative dielectric constant of the quartz dielectric plate is 1.9, and the thickness d of the dielectric layer is 5 - 12 μm.

8. The super-high-sensitivity terahertz antibiotic sensor based on a petal structure according to claim 1, characterized in that, The two resonators are respectively located at the diagonal positions of the dielectric layer, and the shortest distance between the two resonators is 2 μm.

9. The super-high-sensitivity terahertz antibiotic sensor based on a petal structure according to claim 1, characterized in that, The coupling distance s between the two resonators is 2 - 5 μm.

10. The super-high-sensitivity terahertz antibiotic sensor based on a petal structure according to claim 1, characterized in that, Frequency modulation can be achieved within 0.51–1.0 THz. When the modulation peaks at 1.0 THz, it can be used to detect chlortetracycline.

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