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CN-122016706-A - All-medium terahertz sensor based on asymmetric eccentric circle structure and application

CN122016706ACN 122016706 ACN122016706 ACN 122016706ACN-122016706-A

Abstract

The invention discloses an all-dielectric terahertz sensor based on an asymmetric eccentric circle structure, which comprises a quartz substrate layer, wherein a plurality of unit cells are arranged on the quartz substrate layer periodically, the structures of the unit cells are the same, each unit cell comprises a cylindrical silicon body dielectric layer, and a through eccentric hole is vertically formed in the silicon body dielectric layer. The invention also discloses application of the all-medium terahertz sensor based on the asymmetric eccentric circle structure. The invention solves the problem of polarization interference in the prior art and realizes the accurate response of the target polarization signal and the shielding of non-target interference.

Inventors

  • CHEN SUGUO
  • WU RUI
  • WANG YUE
  • CHEN WENSHUO
  • ZHANG QIN

Assignees

  • 西安理工大学

Dates

Publication Date
20260512
Application Date
20260228

Claims (9)

  1. 1. All-dielectric terahertz sensor based on asymmetric eccentric circle structure, characterized by, including quartz substrate layer (2), be provided with a plurality of unit cell (3) of periodic arrangement on quartz substrate layer (2), the structure of a plurality of unit cell (3) is the same, and every unit cell (3) all includes cylindric silicon body dielectric layer (1), has offered eccentric hole (4) that link up perpendicularly on silicon body dielectric layer (1).
  2. 2. The full-dielectric terahertz sensor based on the asymmetric eccentric circle structure according to claim 1, characterized in that the perpendicular bisectors of the eccentric hole (4) and the perpendicular bisectors of the silicon body dielectric layer (1) and the quartz substrate layer (2) are all parallel to each other.
  3. 3. The all-dielectric terahertz sensor based on the asymmetric eccentric circle structure according to claim 1, characterized in that the distance between the center of the eccentric hole (4) and the center of the silicon body dielectric layer (1) is 1-65 μm.
  4. 4. The omnipotent terahertz sensor based on an asymmetric eccentric circle structure according to claim 1, characterized in that the array formed by several of the unit cells (3) is a periodic array of a 4 x 4 matrix.
  5. 5. The full-dielectric terahertz sensor based on the asymmetric eccentric circle structure according to claim 1, characterized in that the thickness of the silicon body dielectric layer (1) is h 1 , which ranges from 50 to 150 μm.
  6. 6. The omnipotent terahertz sensor based on an asymmetric eccentric circle structure according to claim 1, characterized in that the thickness of the quartz substrate layer (2) is h 2 , where h 2 =5h 1 .
  7. 7. The all-dielectric terahertz sensor based on an asymmetric eccentric circle structure according to claim 1, characterized in that the quartz substrate layer (2) is of a square structure.
  8. 8. The application of the all-medium terahertz sensor based on the asymmetric eccentric circle structure is characterized in that the precise distinguishing and identification of various trace substances in a mixed system are realized by depending on a polarization direction sensitive BIC regulation mechanism.
  9. 9. The application of the all-dielectric terahertz sensor based on the asymmetric eccentric circular structure according to claim 8, wherein the specific application is that the asymmetry is broken by introducing perturbation into the super-surface unit cell, so that an ideal BIC local electromagnetic field is partially coupled to the far field to form a quasi-BIC mode, the mode has high Q factor characteristic and observable far field response, meanwhile, the incident direction of X, Y orthogonal polarized terahertz waves is regulated and controlled, a plurality of quasi-BIC modes which are not interfered with each other are respectively excited by polarized light in different directions, each mode corresponds to a special detection channel, the resonance frequency, Q factor and near field enhancement area of different channels have obvious differences, after a mixed substance is loaded on the super-surface, the terahertz fingerprint characteristics of different components are quite different, selective response can be generated on specific frequency points of specific polarization channels, and the characteristics can be applied to biomolecular trace detection, chemical substance component analysis or environmental pollutant precise identification.

Description

All-medium terahertz sensor based on asymmetric eccentric circle structure and application Technical Field The invention belongs to the technical field of terahertz function devices and high-sensitivity sensing, and particularly relates to an all-medium terahertz sensor based on an asymmetric eccentric circle structure, and application of the all-medium terahertz sensor based on the asymmetric eccentric circle structure. Background Terahertz waves refer to electromagnetic waves with frequencies ranging from 0.1 terahertz to 10 terahertz (THz), the wavelength ranges between microwaves and infrared waves, and the terahertz waves are focused in the sensing field due to the advantages of fingerprint spectrum characteristics, low energy loss and the like, but weak interaction between the terahertz waves and natural materials causes a THz device lacking high performance, so that a sub-wavelength micro/nano-structure array with novel optical characteristics, which is designed and manufactured manually, has the capability of flexibly and efficiently manipulating the THz waves, but the quality factor (Q value) of the resonance peak of a terahertz-based super-surface sensor is limited to be between tens to hundreds due to high energy loss caused by multi-dimensional factors such as terahertz frequency band characteristics, material properties, structural design and preparation process. The bound state (BIC) in the continuum is a non-radiative state theoretically having an infinite Q factor, and decoupling it from the continuum prevents energy leakage, can significantly increase the Q of the super-surface resonator, and high Q resonators can significantly enhance the interaction between the structure and light, and thus are widely used for trace species detection. The existing THz all-medium BIC sensor has two key limitations that on one hand, a symmetrical unit cell structure forms a single BIC resonance peak by mode interference of a symmetrical structure, the number of modes is limited and the function is single, and on the other hand, even if part of schemes introduce double polarization directions, BIC mode frequencies of the two polarization directions are overlapped due to insufficient structural design, stable polarization response cannot be realized, interference of non-target polarized direction waves is easy to occur, the anti-interference capability is weak, and the sensing stability and the signal accuracy are seriously affected. Disclosure of Invention The invention aims to provide an all-dielectric terahertz sensor based on an asymmetric eccentric circle structure, solves the problem of polarization interference in the prior art, and realizes accurate response of a target polarized signal and shielding of non-target interference. It is another object of the present invention to provide an application of an all-dielectric terahertz sensor based on an asymmetric eccentric circle structure. The invention adopts a first technical scheme that the all-dielectric terahertz sensor based on the asymmetric eccentric circle structure comprises a quartz substrate layer, wherein a plurality of unit cells are arranged on the quartz substrate layer in a periodic manner, the structures of the unit cells are the same, each unit cell comprises a cylindrical silicon body medium layer, and a through eccentric hole is vertically formed in the silicon body medium layer. The first aspect of the present invention is also characterized in that, The center vertical line of the eccentric hole and the center vertical line of the silicon medium layer are parallel to each other. The distance between the center of the eccentric hole and the center of the silicon medium layer is 1-65 μm. The array of unit cells is a periodic array of a 4 x4 matrix. The thickness of the silicon body dielectric layer is h 1, and the range of the thickness is 50-150 mu m. The thickness of the quartz substrate layer is h 2, where h 2=5h1. The quartz substrate layer has a square structure. The second technical scheme adopted by the invention is that the application of the all-medium terahertz sensor based on the asymmetric eccentric circle structure depends on a polarization direction sensitive BIC regulation mechanism, so that the precise distinguishing and identification of various trace substances in a mixed system are realized. The second aspect of the present invention is also characterized in that, Specifically, by introducing perturbation to break symmetry in the ultra-surface unit cell, the ideal BIC local electromagnetic field is partially coupled to the far field to form a quasi-BIC mode, the mode has high Q factor characteristic and observable far field response, meanwhile, the incident direction of X, Y orthogonal polarized terahertz waves is regulated and controlled, a plurality of quasi-BIC modes which are not interfered with each other are respectively excited by polarized light in different directions, each mode corresponds to a special det