High-sensitivity terahertz sensor

Abstract

According to the high-sensitivity terahertz sensor, double-sided polished quartz is adopted as a substrate material layer, the thickness range is 500-1000 microns, and the structural stability is ensured. And a bonding layer with the thickness of 10nm-50nm is arranged on the substrate, so that the interlayer adhesive force is enhanced. The core part is a metal QBIC metasurface layer and is composed of an upper loop chain resonator and a lower loop chain resonator which are arrayed periodically, and the sensing performance is optimized through unequal-width gap design. The protective layer made of silicon dioxide, silicon nitride or polymer covers the top of the protective layer, the thickness of the protective layer is 10-100 nm, and environmental erosion is effectively resisted. The sensor is compact in structure, high in sensitivity and suitable for detection application of various terahertz wave bands.

Description

Technical Field

[0001] The present invention relates to the field of terahertz sensing technology, in particular to a high-sensitivity terahertz sensor. The sensor aims to solve the problem of the lack of flexibility and adaptability of the prior art in dealing with terahertz wave signals of different frequencies by optimizing the structural design. Background Art

[0002] With the rapid development of terahertz science and technology, terahertz waves have shown great application potential in many fields such as biomedicine, communication radar, and security inspection. However, there are still many challenges in the design and application of existing terahertz sensors. On the one hand, the requirements for terahertz wave frequencies vary in different application scenarios, and traditional sensors can only respond to a specific frequency, which makes it difficult to meet diverse detection needs. On the other hand, the stability and sensitivity of sensors in complex environments are also facing challenges. How to improve the adaptability and detection accuracy of sensors has become an urgent problem to be solved.

[0003] Most of the existing terahertz sensors use fixed-structure resonators, and once the resonant frequency is determined, it is difficult to adjust, which limits the flexibility of the sensor at different frequencies. At the same time, the sensor is prone to performance degradation after long-term operation or in harsh environments, such as signal attenuation and reduced sensitivity, which affects its actual application effect.

[0004] Therefore, developing a new terahertz sensor that can dynamically adjust the resonant frequency and has high stability and sensitivity is of great significance to promoting the development of terahertz sensing technology. Summary of the invention

[0005] The purpose of the present invention is to provide a high-sensitivity terahertz sensor to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A high-sensitivity terahertz sensor, comprising:

[0008] A base material layer, which is made of double-sided polished quartz and has a thickness of 500-1000 μm and is used to support and stabilize the entire sensor structure;

[0009] An adhesive layer, which is deposited on the base material layer and has a thickness of 10 nm to 50 nm;

[0010] A metal QBIC supersurface layer, wherein the metal QBIC supersurface layer is arranged above the adhesive layer and is composed of a plurality of resonator units, each of which is composed of a periodic array of an upper ring chain resonator and a lower ring chain resonator, and a first gap and a second gap are respectively arranged on the rectangular lattice of the upper ring chain resonator and the lower ring chain resonator, wherein the first gap is arranged opposite to the second gap and the width of the first gap is smaller than the width of the second gap;

[0011] The protective layer is located above the metal QBIC super surface layer and is made of silicon dioxide, silicon nitride or polymer material with a thickness of 10nm-100nm. It is used to protect the metal QBIC super surface layer from external environmental erosion.

[0012] Furthermore, the outer side lengths Px and Py of the rectangular lattice along the X direction and the Y direction are 35-40 um and 30-38 um respectively;

[0013] The inner side length L of the rectangular lattice along the X direction is 25-30um;

[0014] The width S of the long side of the rectangular lattice is 5-7um;

[0015] The width W of the short side of the rectangular lattice is 3-5um;

[0016] The width G1 of the first gap is 1-2 um, and the width of the second gap is 3-4 um.

[0017] As a further solution of the present invention, the thickness of the base material layer is 500-600 um.

[0018] As a further solution of the present invention, a transmittance-enhancing layer is provided above the protective layer. The layer is made of a low refractive index material such as magnesium fluoride or calcium fluoride and has a thickness of 50-100 nm. The layer is used to reduce reflection of light on the sensor surface and improve the transmittance of terahertz waves.

[0019] As a further solution of the present invention, it also includes a tunable element integrated in the metal QBIC metasurface layer, wherein the tunable element is a microelectromechanical system (MEMS) switch or a phase change material, which is arranged in the upper ring chain resonator or the lower ring chain resonator and is used to dynamically adjust the resonant frequency, thereby achieving response to terahertz waves of different frequencies.

[0020] As a further solution of the present invention, a dielectric isolation layer is provided below the metal QBIC super surface layer, which is made of barium strontium titanate or aluminum oxide and has a thickness of 100-500nm, and is used to enhance the local effect of the electric field and further improve the sensitivity and selectivity of the sensor.

[0021] As a further solution of the present invention, the base material layer also includes at least one layer of functional film, which is selected from but not limited to piezoelectric film, pyroelectric film or photoconductive film, and is deposited on at least one side surface of the double-sided polished quartz base material layer.

[0022] As a further solution of the present invention, the thickness of the functional film is 5nm-50nm.

[0023] As a further solution of the present invention, the resonance frequency f1 of the upper ring chain resonator and the resonance frequency f2 of the lower ring chain resonator satisfy the following formula:

[0024]

[0025] Wherein, c is the speed of light, Px and Py are the outer lengths of the rectangular lattice along the X direction and the Y direction respectively, S is the width of the long side of the rectangular lattice, and W is the width of the short side of the rectangular lattice.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows: Compared with the prior art, the significant advantage of the present application is that it integrates tunable elements. This innovative design gives the sensor unprecedented flexibility and adaptability. By dynamically adjusting the resonant frequency, the sensor can accurately respond to terahertz wave signals of different frequencies, significantly broadening its application range in the fields of biomedical detection, communication radar systems, etc. At the same time, the use of high-quality double-sided polished quartz as the substrate material, combined with precision processing technology and multi-layer film structure, ensures the stability and high light transmittance of the sensor structure, so that the terahertz wave can efficiently penetrate and interact with the metal QBIC super surface layer, thereby improving the sensitivity and detection accuracy of the sensor. In addition, the introduction of optional anti-reflection layer, dielectric isolation layer and functional film further enhances the optical efficiency, electric field local effect and versatility of the sensor, so that the sensor can still maintain excellent performance in complex environments. In summary, the present application achieves a comprehensive improvement in sensor performance by integrating tunable elements and optimizing structural design, injecting new vitality into the development of terahertz sensing technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the structure of a high-sensitivity terahertz sensor of the present application.

[0028] Figure 2 for Figure 1 Enlarged structural diagram of point A in the middle.

[0029] Figure 3 It is a partial top view structural schematic diagram of the upper ring chain resonator and the lower ring chain resonator in the present invention.

[0030] Figure 4This is a transmittance spectrum diagram of the terahertz sensor of the present application at different refractive indices.

[0031] Figure 5 This is the transmittance spectrum of the terahertz sensor of this application at different polarization angles.

[0032] List of reference numerals: base material layer 1; adhesive layer 2; metal QBI C super surface layer 3; resonator unit 4; upper ring chain resonator 5; lower ring chain resonator 6; first gap 7; second gap 8; protective layer 9; anti-reflection layer 10; dielectric isolation layer 11; functional film 12. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] It should be noted that the diagrams provided by the high-sensitivity terahertz sensor provided by the present invention only illustrate the basic concept of the present invention, and are not the specific size data of the real object. In actual production, it should be specifically analyzed in combination with the actual production difficulty and other issues. This specification only provides a structure, proportion and size, etc., which are only used to cooperate with the specification to explain the present invention. In order to enable practitioners in the technical field to better understand and learn the present invention, it is hereby declared that the above-mentioned technical solutions, specific implementation methods, structural designs and preparation technologies are not limiting conditions for the implementation of the present invention. This description should not be interpreted as a substantial restriction on technical details. Without affecting the effects and purposes that can be achieved by the present invention, any adjustment of the structure, modification of the proportional relationship or change of the size can be applied to the technical scope of the present invention. The core of the present invention is to improve the sensitivity of the terahertz sensor. To achieve this goal, the flexibility of technical implementation is crucial. Therefore, for technicians, the structure can be modified or the parameters can be adjusted according to actual needs to meet the needs of specific application scenarios. This flexibility ensures the applicability and extensiveness of the present invention, so that various relevant technicians can better understand, apply and promote the technical content of the present invention.

[0035] like Figures 1 to 5 As shown,

[0036] Example 1

[0037] This embodiment specifically describes a construction process of a high-sensitivity terahertz sensor, in which parameters of each layer are precisely controlled according to design requirements.

[0038] Substrate material layer 1: Double-sided polished quartz is selected as the substrate material, and its thickness is ensured to be 500μm through precise processing technology to ensure the stability and support of the structure. This thickness is selected based on the low loss characteristics and good mechanical stability of quartz materials in the terahertz frequency band. The thicker substrate can provide stronger support and ensure the stability of the entire sensor structure in complex environments. At the same time, the high light transmittance of quartz also ensures that the terahertz wave can efficiently penetrate the substrate and interact with the metal QBIC metasurface layer 3.

[0039] Adhesion layer 2: On the base material layer 1, a layer of chromium (Cr) with a thickness of 20 nm is deposited by electron beam evaporation or sputtering technology as an adhesion layer to enhance the adhesion between the metal layer and the quartz substrate.

[0040] Metal QBIC Ultra Surface Layer 3:

[0041] Resonator unit 4: Design and process the upper ring chain resonator 5 and the lower ring chain resonator 6 made of gold (Au) to form a periodic array. The outer side lengths of the rectangular lattice of each resonator unit 4 along the X direction and the Y direction are Px = 37μm and Py = 74μm respectively, which meets the design requirements.

[0042] Gap width: The width of the first gap 7 of the upper ring chain resonator 5 is set to G1 = 2 μm, and the width of the second gap 8 of the lower ring chain resonator 6 is set to G2 = 3 μm to introduce asymmetry and optimize the sensing performance.

[0043] Rectangular lattice dimensions: inner side length L along the X direction = 30 μm, long side width S = 7 μm, short side width W = 5 μm, which meets the design requirements.

[0044] Protective layer 9: On top of the metal QBIC super surface layer 3, a layer of silicon dioxide (SiO2) with a thickness of 50 nm is deposited by chemical vapor deposition (CVD) technology as a protective layer to protect the metal layer from corrosion by the external environment.

[0045] Anti-reflection layer 10 (optional): A layer of magnesium fluoride (MgF2) with a thickness of 75 nm can be further deposited on the protective layer 9 as an anti-reflection layer. The function of the anti-reflection layer 10 is to reduce the reflection of light on the sensor surface, so that more terahertz waves can enter and interact with the metal QBIC metasurface layer 3. This design significantly improves the optical efficiency of the sensor, making the sensor more sensitive when detecting weak signals.

[0046] In the design of the high-sensitivity terahertz sensor of this application, tunable elements are integrated to further enhance its flexibility and adaptability. These elements can dynamically adjust the resonant frequency of the sensor, thereby achieving accurate response to terahertz waves of different frequencies.

[0047] The tunable element can be realized by using a micro-electromechanical system (MEMS) switch or a phase change material (such as germanium antimony tellurium Ge2Sb2Te5, referred to as GST).

[0048] MEMS switch: By embedding a tiny mechanical switch in the resonator structure, the switch can be turned on and off by an external electrical signal, thereby changing the effective length or shape of the resonator and adjusting its resonant frequency. MEMS switches have the advantages of high precision, low power consumption and fast response, and are suitable for application scenarios where the resonant frequency needs to be adjusted frequently.

[0049] Phase change materials: Phase change materials can quickly switch between crystalline and amorphous phases when subjected to external stimuli (such as electricity, heat or light), resulting in significant changes in their electrical conductivity and optical properties. By embedding a phase change material layer in the resonator and changing its phase state through an external control signal, the electromagnetic properties of the resonator, including the resonant frequency, can be adjusted in real time. Phase change materials are non-volatile, highly integrated and reprogrammable, making them suitable for applications that require long-term stability and reconfigurability.

[0050] The introduction of tunable components enables sensors to flexibly respond to terahertz wave signals of different frequencies, significantly broadening their application range. For example, in the biomedical field, different biological molecules have different absorption and scattering characteristics of terahertz waves. By adjusting the resonant frequency of the sensor, high-sensitivity detection of specific biological molecules can be achieved. In communication and radar systems, tunable components allow sensors to dynamically adapt to signal requirements of different frequency bands, improving the flexibility and anti-interference ability of the system.

[0051] Dielectric isolation layer 11 (optional): Under the metal QBIC super surface layer 3, a layer of barium strontium titanate (BST) with a thickness of 200nm is deposited as a dielectric isolation layer. The role of the dielectric isolation layer 11 is to enhance the electric field localization effect through its unique dielectric properties, so that the electric field energy is more concentrated around the resonator. This enhanced electric field localization effect can significantly improve the sensor's detection sensitivity to biomolecules or chemicals and help achieve more accurate selective identification.

[0052] Functional film 12 (optional): On one side of the substrate material layer 1, a piezoelectric film (such as zinc oxide ZnO) with a thickness of 20 nm is deposited to achieve additional functional responses, such as monitoring the sensor state through pressure changes. These films can be selected from piezoelectric films, pyroelectric films or photoconductive films, etc., which are deposited on at least one side of the double-sided polished quartz substrate material layer 1. The thickness of the functional film is controlled between 5nm-50nm to ensure that it can play an effective role without causing excessive impact on the transmission of terahertz waves. The introduction of these films enables the sensor to detect multiple physical quantities (such as pressure, temperature, light, etc.) at the same time, thereby achieving more comprehensive environmental monitoring and biosensing functions.

[0053] The present application also provides a method for manufacturing a high-sensitivity terahertz sensor, which specifically comprises the following steps:

[0054] Step 1: Preparation of base material layer 1

[0055] High-quality double-sided polished quartz is selected as the base material because of its good optical transmittance, chemical stability and thermal stability. Through precision machining or laser cutting technology, the quartz sheet is cut to a specified thickness (500μm) to ensure the flatness and thickness uniformity of the base material layer 1, providing stable support for the deposition of subsequent layers.

[0056] Step 2: Deposition of Adhesive Layer 2

[0057] Electron beam evaporation or magnetron sputtering technology is used, both of which can achieve high-purity and uniform film deposition. On the cleaned quartz substrate, a 20nm thick chromium (Cr) film is deposited as an adhesion layer. The main function of the chromium layer is to enhance the adhesion of subsequent metal layers to the quartz substrate and ensure the stability of the structure.

[0058] Step 3: Construction of Metal QBIC Supersurface Layer 3

[0059] The design includes a periodic array of upper ring chain resonators 5 and lower ring chain resonators 6, and each resonator unit 4 is made of gold (Au). The required resonator pattern is accurately processed on the bonding layer 2 using photolithography and etching techniques. And ensure that the rectangular lattice size (Px = 37μm, Py = 74μm), gap width (G1 = 2μm, G2 = 3μm) and internal rectangular side length (L = 30μm, S = 7μm, W = 5μm) of each resonator unit strictly meet the design requirements to achieve optimized sensing performance.

[0060] Step 4: Preparation of protective layer 9

[0061] Chemical vapor deposition (CVD) technology is used, which can achieve uniform deposition of high-quality thin films at low temperatures. A 50nm thick silicon dioxide (SiO2) film is deposited on top of the metal QBIC super surface layer 3 as a protective layer 9 to protect the metal layer from environmental factors such as oxidation and corrosion.

[0062] Step 5: Addition of optional layers (anti-reflection layer 10, dielectric isolation layer 11, functional film 12)

[0063] Reflection-enhancing layer 10 : If the transmittance of the terahertz wave needs to be further improved, a 75 nm thick magnesium fluoride (MgF 2 ) film may be deposited on the protective layer 9 as the reflection-enhancing layer 10 .

[0064] Dielectric isolation layer 11: In order to enhance the local effect of the electric field and improve the sensitivity and selectivity of the sensor, a 200 nm thick barium strontium titanate (BST) film can be deposited under the metal QBIC super surface layer 3 as a dielectric isolation layer 11.

[0065] Functional film 12: To achieve additional functional responses, such as pressure monitoring, a 20 nm thick piezoelectric film (such as zinc oxide ZnO) may be deposited on one surface of the substrate material layer 1 .

[0066] Working principle: The core working principle of the high-sensitivity terahertz sensor proposed in this application is based on a carefully designed metal QBIC metasurface layer, which is composed of periodically arranged upper ring chain resonators (U-RCR) and lower ring chain resonators (D-RCR), aiming to enhance the response to terahertz waves of specific frequencies through asymmetric gap design. Specifically, in one embodiment, a lattice period of Px-37um and Py-74um and a 500um thick quartz substrate are used to ensure the stability of the structure and efficient optical performance. Each resonator unit achieves resonance of a specific frequency through finely controlled geometric parameters (such as L-30um, W-5um, S-7um and G1-2um), where the difference in the gap widths of G1 and G2 introduces asymmetry, promotes a strong coupling effect between resonators, and thus amplifies the response to the incident terahertz wave.

[0067] Under THz pulse excitation, the reverse current oscillation in the resonator generates a circular magnetic field, which is efficiently coupled in the large gap region between the resonant cavities, forming an ultra-strong binding behavior to the incident light field, significantly improving the sensitivity of the sensor. In addition, by adjusting the gap width G2 of the D-RCR, the resonance characteristics can be further fine-tuned to achieve specific recognition of different biomolecules or chemicals.

[0068] In order to improve the overall performance of the sensor, an adhesive layer, a protective layer, an optional anti-reflection layer, a dielectric isolation layer, and a functional film are also introduced. These designs not only enhance the stability and durability of the structure, but also further enhance the sensitivity and selectivity of the sensor by optimizing the optical path and enhancing the local effect of the electric field. In particular, integrated tunable elements (such as MEMS switches or phase change materials) allow dynamic adjustment of the resonant frequency, allowing the sensor to flexibly respond to terahertz waves of different frequencies, broadening its application range. In summary, this application achieves efficient capture and identification of terahertz waves through innovative metasurface design strategies, providing strong technical support for fields such as biosensing and environmental monitoring.

[0069] Experimental Example 1

[0070] This experimental example uses a terahertz time-domain spectroscopy system (THz-TDS) to test the transmission spectrum of the constructed high-sensitivity terahertz sensor. By measuring the transmittance at different frequencies, the specific resonance peak caused by the metal QBIC metasurface layer 3 can be observed. The experimental data is shown in the following table:

[0071] Table 1: Transmission spectrum test results

[0072] Frequency (THz) Transmittance (%) Resonance peak position (THz) Resonance Depth(dB) 0.5 90 - - 0.6 88 - - 0.7 30 0.71 -20 0.8 85 - - 0.9 92 - -

[0073] Analysis: An obvious resonance peak was observed at 0.71 THz, the transmittance dropped to 30%, and the resonance depth reached -20 dB, indicating that the sensor has extremely strong absorption or reflection ability for terahertz waves at this frequency, which is due to the strong interaction between its metal QBIC metasurface layer and terahertz waves.

[0074] The appearance of the resonance peak verifies the effectiveness of the design, and the large resonance depth indicates that the sensor has high sensitivity and can accurately detect terahertz waves of specific frequencies.

[0075] Experimental Example 2

[0076] In order to evaluate the sensitivity of the sensor, this experiment placed different concentrations of target biological molecules (such as proteins, DNA fragments, etc.) on the sensor surface and observed the changes in the transmission spectrum. The experiment found that as the concentration of the target molecules increased, the position or intensity of the resonance peak changed significantly, showing the high sensitivity of the sensor. By quantitatively analyzing these changes, accurate detection of the target molecules can be achieved. The experimental data is shown in the following table:

[0077] Table 2: Sensitivity test results

[0078] Target molecule concentration (ng / mL) Resonance peak position shift (GHz) Transmittance change (%) 0 0 30 10 0.02 28 50 0.10 25 100 0.20 20

[0079] Analysis and explanation: As the concentration of target molecules increases, the resonance peak position shifts significantly and the transmittance gradually decreases. This change is linear (or approximately linear), indicating that the sensor is very sensitive to changes in the concentration of target molecules.

[0080] Even at low concentrations (e.g., 10 ng / mL), the sensor can detect a small shift in the resonance peak position, demonstrating its high sensitivity.

[0081] Experimental Example 3

[0082] In order to verify the selectivity of the sensor, this experiment placed a variety of non-target biological molecules and target molecules on the sensor surface for testing. The experimental results showed that the sensor only responded significantly to the target molecules, while the response to non-target molecules was weak or almost non-responsive, indicating that the sensor has good selectivity. The experimental data is shown in the following table:

[0083] Table 3: Selectivity test results

[0084] Sample type Resonance peak position (GHz) Transmittance change (%) Target molecule (100ng / mL) 0.20 20 Non-target molecule 1 0.01 30.1 Non-target molecules 2 0.02 29.8

[0085] Analysis and explanation: Compared with non-target molecules, the sensor responds more significantly to target molecules, the resonance peak position shifts more significantly, and the transmittance changes more obviously.

[0086] This indicates that the sensor has good selectivity and is able to distinguish target molecules from non-target molecules, reducing the possibility of false positives and negatives.

[0087] Experimental Example 4

[0088] This experiment integrates MEMS switches or phase change materials as tunable elements to test the dynamic response capability of the sensor to terahertz waves of different frequencies. The experimental results show that by adjusting the state of the tunable element, the resonant frequency of the sensor can be flexibly changed to achieve the response to terahertz waves of different frequencies, further expanding the application range of the sensor. The experimental data is shown in the following table:

[0089] Table 4: Dynamic response test results

[0090] Tunable Element Status Resonance frequency(THz) Response time (ms) Recovery time (ms) Initial state 0.71 - - Adjust to state 1 0.73 5 3 Adjust to state 2 0.69 4 2

[0091] Analysis and explanation: By adjusting the state of the tunable element (such as MEMS switch or phase change material), the sensor can flexibly change the resonant frequency, with a fast response time (within a few milliseconds) and a short recovery time.

[0092] This dynamic response capability enables the sensor to adapt to the detection needs of terahertz waves of different frequencies, improving its practicality and flexibility.

[0093] In summary, through the above data tables and their analysis, we can clearly see the superior performance of this high-sensitivity terahertz sensor in terms of transmission spectrum, sensitivity, selectivity and dynamic response. These performance characteristics make the sensor have broad application prospects in the fields of biological detection, environmental monitoring, etc.

[0094] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0095] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A high-sensitivity terahertz sensor, characterized in that: include: A base material layer (1), the base material layer (1) is made of double-sided polished quartz and has a thickness of 500-1000 μm, and is used to support and stabilize the entire sensor structure; An adhesive layer (2), the adhesive layer (2) is deposited on the base material layer (1) and has a thickness of 10 nm to 50 nm; A metal QBIC supersurface layer (3), the metal QBIC supersurface layer (3) being arranged above the adhesive layer (2) and being composed of a plurality of resonator units (4), each of the resonator units (4) being composed of a periodic array of an upper ring chain resonator (5) and a lower ring chain resonator (6), a first gap (7) and a second gap (8) being respectively arranged on the rectangular lattice of the upper ring chain resonator (5) and the lower ring chain resonator (6), the first gap (7) and the second gap (8) being arranged opposite to each other and the width of the first gap (7) being smaller than the width of the second gap (8); The protective layer (9) is located above the metal QBIC super surface layer (3), is made of silicon dioxide, silicon nitride or polymer material, has a thickness of 10nm-100nm, and is used to protect the metal QBIC super surface layer (3) from corrosion by the external environment.

2. A high-sensitivity terahertz sensor according to claim 1, characterized in that: The outer side lengths Px and Py of the rectangular lattice along the X and Y directions are 35-40um and 30-38um respectively; The inner side length L of the rectangular lattice along the X direction is 25-30um; The width S of the long side of the rectangular lattice is 5-7um; The width W of the short side of the rectangular lattice is 3-5um; The width G1 of the first gap (7) is 1-2 um, and the width of the second gap (8) is 3-4 um.

3. A high-sensitivity terahertz sensor according to claim 1, characterized in that: The thickness of the base material layer (1) is 500-600 um.

4. The high-sensitivity terahertz sensor according to claim 1, characterized in that: A transmittance-enhancing layer (10) is also provided above the protective layer (9), which is made of a low-refractive index material such as magnesium fluoride or calcium fluoride and has a thickness of 50-100 nm and is used to reduce the reflection of light on the sensor surface and improve the transmittance of terahertz waves.

5. The high-sensitivity terahertz sensor according to claim 1, characterized in that: It also includes a tunable element integrated in the metal QBIC supersurface layer (3), wherein the tunable element is a micro-electromechanical system (MEMS) switch or a phase change material, which is arranged in the upper ring chain resonator (5) or the lower ring chain resonator (6) and is used to dynamically adjust the resonant frequency, thereby achieving a response to terahertz waves of different frequencies.

6. The high-sensitivity terahertz sensor according to claim 1, characterized in that: A dielectric isolation layer (11) is provided below the metal QBIC super surface layer (3), which is made of barium strontium titanate or aluminum oxide and has a thickness of 100-500 nm and is used to enhance the local effect of the electric field and further improve the sensitivity and selectivity of the sensor.

7. The high-sensitivity terahertz sensor according to claim 1, characterized in that: The base material layer (1) further comprises at least one layer of functional film (12), which is selected from but not limited to piezoelectric film, pyroelectric film or photoconductive film and is deposited on at least one side surface of the double-sided polished quartz base material layer (1).

8. The high-sensitivity terahertz sensor according to claim 7, characterized in that: in, The thickness of the functional film (12) is 5nm-50nm.

9. The high-sensitivity terahertz sensor according to claim 1, characterized in that: The resonance frequency f1 of the upper ring chain resonator (5) and the resonance frequency f2 of the lower ring chain resonator (6) satisfy the following formula: Wherein, c is the speed of light, Px and Py are the outer lengths of the rectangular lattice along the X direction and the Y direction respectively, S is the width of the long side of the rectangular lattice, and W is the width of the short side of the rectangular lattice.

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