Terahertz signal detection fluorescence system based on diamond color center

Abstract

The invention relates to the technical field of terahertz signal detection, and provides a terahertz signal detection fluorescence system based on a diamond color center, and the system comprises an objective table which is provided with a diamond; the terahertz signal generation light path is used for generating a terahertz signal with adjustable frequency and acting on a Pb color center of the diamond; the phonon signal detection light path comprises a fluorescence detection module, a demodulation module and a signal processing module, the fluorescence detection module is used for enabling generated laser to act on the Pb color center of the diamond to generate a mixed fluorescence signal, the demodulation module is used for separating the mixed fluorescence signal to obtain two light signals, the intensity difference is determined according to the two light signals, and the signal processing module is used for processing the intensity difference; the signal processing module is used for determining the numerical value of the terahertz signal based on the electric signal. Therefore, high-sensitivity and direction-selectivity detection and real-time monitoring of terahertz signals can be realized by utilizing the quantum characteristic of the Pb color center of the diamond and the collaborative design of double optical paths.

Description

Technical Field

[0001] This invention relates to the field of terahertz signal detection technology, and in particular to a terahertz signal detection fluorescence system based on diamond color centers. Background Technology

[0002] Driven by the rapid development of wireless communication, biomedicine, and other fields, terahertz technology has become a highly anticipated cutting-edge technology due to its unique advantages such as wide spectrum and high transmission rate. However, in the crucial aspect of terahertz detection, traditional detectors have revealed numerous insurmountable shortcomings. For example, pyroelectric detectors lack sensitivity and often struggle with weak signals, failing to meet the detection requirements of practical applications. Femtosecond laser-based optical detection systems are not only expensive but also bulky, limiting their application in scenarios with strict space and cost constraints. More significantly, most traditional detectors lack directional selectivity and real-time response capabilities, failing to accurately capture signals from specific directions and provide timely feedback. Although nanoscale detection technology has made some progress in recent years, related solutions still have significant shortcomings, making it difficult to simultaneously achieve key indicators such as high sensitivity, compact structure, and polarization-resolved detection. Summary of the Invention

[0003] This invention provides a terahertz signal detection fluorescence system based on diamond color centers to solve the problems of low terahertz detection sensitivity, complex system structure and lack of directional selectivity in the existing technology.

[0004] This invention provides a terahertz signal detection fluorescence system based on diamond color centers, comprising: A stage, wherein the stage is equipped with a diamond; A terahertz signal generation optical path is used to generate a frequency-tunable terahertz signal and act on the Pb color center of the diamond. The phonon signal detection optical path includes a fluorescence detection module, a demodulation module, and a signal processing module. The fluorescence detection module is used to apply the generated laser to the Pb color center of the diamond to generate a mixed fluorescence signal. The demodulation module is used to separate the mixed fluorescence signal to obtain two light signals, determine the intensity difference based on the two light signals, and output a corresponding electrical signal based on the intensity difference. The signal processing module is used to determine the value of the terahertz signal based on the electrical signal.

[0005] According to the present invention, a terahertz signal detection fluorescence system based on diamond color centers is provided, wherein the two optical signals include two first optical signals and two second optical signals, and the determination of the intensity difference based on the two optical signals includes: The intensity difference is determined based on the two first optical signals and the two second optical signals; wherein the two first optical signals correspond to the terahertz signal acting on the Pb color center of the diamond, and the two second optical signals correspond to the terahertz signal not acting on the Pb color center of the diamond.

[0006] According to the present invention, a terahertz signal detection fluorescence system based on diamond color centers is provided, wherein the fluorescence detection module includes a first laser, a beam splitter, an objective lens, a first lens, a pinhole space filter, a bandpass filter, and a Glan Taylor prism. The objective lens, the beam splitter, the pinhole space filter, the first lens, the bandpass filter, and the Glan Taylor prism are arranged in sequence. The laser output from the first laser passes through the beam splitter and the objective lens in sequence and acts on the Pb color center of the diamond.

[0007] According to the present invention, a terahertz signal detection fluorescence system based on diamond color centers is provided, wherein the terahertz signal generation optical path includes a second laser, the first laser outputs a first laser with a first wavelength, and the second laser outputs a second laser with a second wavelength, wherein the first wavelength is equal to the second wavelength.

[0008] According to the present invention, a terahertz signal detection fluorescence system based on diamond color centers is provided. The demodulation module includes a Wollaston prism, a mirror group, and a balanced detector arranged sequentially. The Wollaston prism is used to separate the mixed fluorescence signal to obtain two light signals. The two light signals are reflected by the mirror group and enter the balanced detector. The balanced detector determines the intensity difference based on the two light signals and outputs a corresponding electrical signal based on the intensity difference.

[0009] According to the present invention, a terahertz signal detection fluorescence system based on diamond color centers is provided, wherein the beam splitting angle of the Wollaston prism is 15°±0.5°, and the path difference between the two light signals is less than or equal to 5μm; and / or, The common-mode rejection ratio of the balanced detector is greater than or equal to 80dB, and the bandwidth is greater than or equal to 1MHz.

[0010] According to the present invention, a terahertz signal detection fluorescence system based on diamond color centers is provided. The terahertz signal generation optical path includes a main terahertz signal generation path and a terahertz signal correction branch. The main terahertz signal generation path is used to generate a frequency-tunable terahertz signal, and the terahertz signal correction branch is used to determine the value of the terahertz signal.

[0011] According to the present invention, a terahertz signal detection fluorescence system based on diamond color centers is provided, wherein the frequency range of the terahertz signal is 0.1~30THz.

[0012] According to the present invention, a terahertz signal detection fluorescence system based on diamond color centers is provided, wherein the diamond is a type IIa single-crystal diamond, and Pb element is implanted into the diamond using ion implantation technology, wherein the implantation dose is greater than or equal to 1 × 10⁻⁶. 8 ion / cm 2 .

[0013] According to the present invention, a terahertz signal detection fluorescence system based on diamond color centers is provided, wherein the diamond is subjected to an annealing operation, wherein the annealing temperature is greater than or equal to 1000℃; the annealing time is greater than or equal to 1h; and the annealing vacuum degree is greater than or equal to 1×10⁻⁶. -4 Pa.

[0014] The present invention provides a terahertz signal detection fluorescence system based on diamond color centers. The fluorescence detection module precisely focuses a laser onto the Pb color center of diamond, exciting it to generate a zero-phonon line signal containing two orthogonally polarized characteristic peaks at 554 nm (C peak) and 558 nm (D peak). The fluorescence signal emitted by the Pb color center finally enters the demodulation module. The demodulation module can separate the mixed signal of C peak and D peak into two first light signals with an angle of 15°, referred to as signal 1 and signal 2, respectively. Signal 1 and signal 2 contain different proportions of C peak and D peak components. When the terahertz signal generating optical path applies controllable terahertz radiation to the Pb color center, if the Pb color center responds, its local lattice will absorb terahertz energy and cause changes in phonon state vibrations, which in turn causes a shift in the relative intensity of the C peak and D peak, causing changes in the intensity of signal 1 and signal 2. This change is sensitively captured by the demodulation module and reflected through changes in electrical signals, thereby realizing the indirect detection of terahertz signals. Thus, by utilizing the quantum properties of Pb color centers in diamond and the dual-optical-path collaborative design, high-sensitivity, direction-selective detection, and real-time monitoring of terahertz signals can be achieved. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of the terahertz signal detection fluorescence system based on diamond color centers provided by the present invention.

[0017] Figure 2 This is the fluorescence spectrum of the Pb color center provided by the present invention.

[0018] Figure 3This is a schematic diagram of the fluorescence intensity of the C peak and D peak at different polarization angles provided by the present invention.

[0019] Figure 4 This is a structural diagram of the Pb color center provided by the present invention.

[0020] Figure label: 11. Stage; 12. Pb color center; 21. First laser; 22. First mirror; 23. Beam splitter; 24. Objective lens; 25. Pinhole space filter; 26. First lens; 27. Bandpass filter; 28. Glan-Taylor prism; 29. ​​Quarter wave plate; 31. Wollaston prism; 32. Mirror group; 33. Balanced detector; 41. Signal processing module; 51. Second laser; 52. Polarizing beam splitter; 53. First dichroic mirror; 54. First KTP crystal; 55. Second KTP crystal; 56. First DAST crystal; 57. Germanium plate; 58. Off-axis parabolic mirror; 59. Second dichroic mirror; 60. Third KTP crystal; 61. Second DAST crystal; 62. Detector. Detailed Implementation

[0021] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly set on the other component; when a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to the other component.

[0023] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "a plurality of" or "several" means two or more, unless otherwise explicitly specified.

[0025] It should be noted that the structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which this application can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0026] like Figure 1 As shown, the terahertz signal detection fluorescence system based on diamond color centers according to an embodiment of the present invention includes: a stage 11, a terahertz signal generation optical path, and a phonon signal detection optical path.

[0027] The stage 11 is equipped with a diamond; the terahertz signal generation optical path is used to generate a frequency-tunable terahertz signal and act on the Pb color center 12 of the diamond; the phonon signal detection optical path includes a fluorescence detection module, a demodulation module, and a signal processing module 41. The fluorescence detection module is used to act the generated laser on the Pb color center 12 of the diamond to generate a mixed fluorescence signal. The demodulation module is used to separate the mixed fluorescence signal to obtain two light signals, determine the intensity difference based on the two light signals, and output the corresponding electrical signal based on the intensity difference. The signal processing module 41 is used to determine the value of the terahertz signal based on the electrical signal.

[0028] It should be noted that the two light signals include two first light signals and two second light signals. Thus, determining the intensity difference based on the two light signals includes: determining the intensity difference based on the two first light signals and the two second light signals; wherein, the two first light signals correspond to the terahertz signal acting on the Pb color center 12 of diamond, and the two second light signals correspond to the terahertz signal not acting on the Pb color center 12 of diamond.

[0029] like Figure 2 As shown, fluorescence spectroscopy measurements were performed on the Pb color centers of diamond, revealing two characteristic fluorescence peaks at 554 nm and 558 nm, corresponding to the C and D peaks, respectively. Further measurements of the fluorescence intensity of the Pb color centers under excitation light at different polarization angles were conducted using a polarizer. Figure 3As shown, the results indicate that the polarization angles corresponding to the extreme points of intensity variation of the two peaks differ by approximately 90°, suggesting that the polarization directions of peak C and peak D are perpendicular to each other. Combined with atomic structure analysis of the Pb color center, as shown... Figure 4 As shown, Pb atoms are located in the interstitial positions formed by 6 C atoms in the diamond lattice, forming a D3d symmetric structure. The generation of its C peak and D peak originates from the orthogonal polarization transition process caused by the excitation of polarized light in different directions after the electron splits in the ground state energy level.

[0030] Specifically, the fluorescence detection module uses a 532nm laser as the excitation source, precisely focusing the laser onto the Pb color center 12 of the diamond, exciting it to generate a zero-phonon line signal containing two orthogonally polarized characteristic peaks at 554nm (C peak) and 558nm (D peak). The fluorescence signal emitted by the Pb color center 12 finally enters the demodulation module. The demodulation module can separate the mixed signal of the C peak and D peak into two first light signals with an angle of 15°, referred to as signal 1 and signal 2, according to the orthogonal polarization direction. Signal 1 and signal 2 contain C peak and D peak components in different proportions. The demodulation module can detect the intensity difference between the two peaks in real time and convert it into an electrical signal. In other words, when the terahertz signal generating optical path applies controllable terahertz radiation to the Pb color center 12, if the Pb color center 12 responds, its local lattice will absorb terahertz energy and cause changes in phonon state vibrations, which in turn causes a shift in the relative intensity of the C peak and the D peak, resulting in changes in the intensity of signal 1 and signal 2. This change is sensitively captured by the demodulation module and reflected through changes in electrical signals, thereby achieving indirect detection of terahertz signals.

[0031] The terahertz signal detection fluorescence system based on diamond color centers in this invention utilizes the quantum properties of Pb color center 12 in diamond and a dual-optical-path collaborative design to achieve high-sensitivity, direction-selective detection and real-time monitoring of terahertz signals.

[0032] It should be noted here that the signal processing module 41 is also used to perform the following operations: In the absence of terahertz radiation, the initial reference values ​​R for calibrating signal 1 and signal 2 are determined; Real-time measurement of R1 values ​​after applying terahertz signals of different frequency bands; Calculate the rate of change of strength difference: η = |(R1-R) / R| × 100%; When η≥0.1%, it is determined to be an effective terahertz signal response.

[0033] In optional embodiments, such as Figure 1As shown, the fluorescence detection module includes a first laser 21, a beam splitter 23, an objective lens 24, a first lens 26, a pinhole spatial filter 25, a bandpass filter 27, and a Glan Taylor prism 28. The objective lens 24, beam splitter 23, pinhole spatial filter 25, first lens 26, bandpass filter 27, and Glan Taylor prism 28 are arranged sequentially. The laser output from the first laser 21 passes through the beam splitter 23 and the objective lens 24 in sequence and acts on the Pb color center 12 of the diamond.

[0034] Specifically, objective lens 24 can be a 100x objective lens 24, pinhole space filter 25 can be a 50μm pinhole space filter 25, and bandpass filter 27 can be a 554~558nm bandpass filter 27. Additionally, the first lens 26 can be a convex lens. Furthermore, to facilitate optical path adjustment, a first reflecting mirror 22 and a second reflecting mirror are sequentially arranged between the first laser 21 and the beam splitter 23.

[0035] It should be noted that the fluorescence signal emitted by the Pb color center 12 is reflected by the beam splitter 23, filtered by the 50μm pinhole space filter 25 to improve the signal-to-noise ratio, collimated into parallel light by the first lens 26, and then passed through the 554~558nm bandpass filter 27 to remove stray light. Subsequently, it enters the Glan Taylor prism 28 to convert the fluorescence into linearly polarized light with a high extinction ratio (>1000:1), and then modulated into elliptically polarized light by the quarter wave plate 29 to optimize the polarization state control accuracy. Finally, it enters the demodulation module.

[0036] In optional embodiments, such as Figure 1 As shown, the terahertz signal generation optical path includes a second laser 51, a first laser 21 outputting a first laser with a first wavelength, and a second laser 51 outputting a second laser with a second wavelength, wherein the first wavelength is equal to the second wavelength. Both the first and second wavelengths can be 532 nm. The power of the first laser 21 and the second laser 51 can be adjusted from 0 to 50 mW.

[0037] It is particularly important to note that the terahertz signal generation optical path and the phonon signal detection optical path can share the same 532nm laser source. Through beam splitting, the energy of the laser source can be rationally allocated and the time synchronization between the two optical paths can be achieved, thereby effectively avoiding errors introduced by fluctuations in the external light source.

[0038] In optional embodiments, such as Figure 1 As shown, the demodulation module includes a Wollaston prism 31, a mirror group 32, and a balance detector 33 arranged in sequence. The Wollaston prism 31 is used to separate the mixed fluorescence signal to obtain two light signals. The two light signals are reflected by the mirror group 32 and enter the balance detector 33. The balance detector 33 determines the intensity difference based on the two light signals and outputs the corresponding electrical signal based on the intensity difference.

[0039] It should be noted that the fluorescence signal emitted by the Pb color center 12 enters the Wollaston prism 31. The Wollaston prism 31 separates the mixed signal of the C and D peaks into signal 1 and signal 2 with an angle of 15° along orthogonal polarization directions. Signal 1 and signal 2 then enter the balanced detector 33 through their respective mirrors. When the terahertz signal generating optical path applies controllable terahertz radiation to the Pb color center 12, if the Pb color center 12 responds, its local lattice absorbs terahertz energy and causes changes in phonon state vibrations, leading to a shift in the relative intensity of the C and D peaks. This results in changes in the intensity of signal 1 and signal 2, which are sensitively captured by the balanced detector 33 and reflected through changes in electrical signals.

[0040] In practical applications, the beam splitting angle of the Wollaston prism 31 is 15°±0.5°, and the path difference between the two light signals is less than or equal to 5μm; the common-mode rejection ratio of the balanced detector 33 is greater than or equal to 80dB, and the bandwidth is greater than or equal to 1MHz.

[0041] In optional embodiments, such as Figure 1 As shown, the terahertz signal generation optical path includes a main terahertz signal generation path and a terahertz signal correction branch. The main terahertz signal generation path is used to generate a frequency-tunable terahertz signal, and the terahertz signal correction branch is used to determine the value of the terahertz signal. The frequency range of the terahertz signal is 0.1~30THz.

[0042] Specifically, the main terahertz signal generation path includes a second laser 51, a third mirror, a first half-wave plate, a cable beam splitter, a polarizing beam splitter 52, a second half-wave plate, a first dichroic mirror 53, a first deformable mirror, a first KTP crystal 54, a second KTP crystal 55, a fourth mirror, a first filter, a second lens, a first DAST crystal 56, a third lens, a germanium plate 57, and an off-axis parabolic mirror 58. The second laser 51, the third mirror, the first half-wave plate, the cable beam splitter, the polarizing beam splitter 52, the second half-wave plate, and the first dichroic mirror 53 are arranged sequentially. The first deformable mirror, the first KTP crystal 54, the second KTP crystal 55, and the fourth mirror are arranged sequentially on one side of the first dichroic mirror 53. The first filter, the second lens, the first DAST crystal 56, the third lens, the germanium plate 57, and the off-axis parabolic mirror 58 are arranged sequentially on the other side of the first dichroic mirror 53.

[0043] The terahertz signal correction branch includes a fifth reflector, a second dichroic mirror 59, a second deformable reflector, a third KTP crystal 60, a sixth reflector, a second filter, a fourth lens, a fifth lens, a second DAST crystal 61, a sixth lens, a seventh reflector, an eighth reflector, a third filter, a seventh lens, and a detector 62. The fifth reflector and the second dichroic mirror 59 are arranged sequentially. The second deformable reflector, the third KTP crystal 60, and the sixth reflector are arranged sequentially on one side of the second dichroic mirror 59. The second filter, the fourth lens, the fifth lens, the second DAST crystal 61, the sixth lens, the seventh reflector, the eighth reflector, the third filter, the seventh lens, and the detector 62 are arranged sequentially on the other side of the second dichroic mirror 59.

[0044] It should be noted that a 532nm laser is used as the light source. After the polarization direction is adjusted by the first half-wave plate and the divergence is optimized by the beam shrinking mirror, it is split into two beams by the polarization beam splitter 52. One main beam is used for terahertz signal generation, and the other reference beam is used for frequency calibration. After being reflected by the first dichroic mirror 53, the main beam passes sequentially through the first KTP crystal 54 at a fixed angle and the second KTP crystal 55 at a rotatable angle. The optical difference frequency effect generates a frequency-tunable terahertz signal. The first KTP crystal 54 is fixed to stabilize the λ1 frequency, and the second KTP crystal 55 is rotated to adjust the λ2 frequency, so that the difference frequency of the two beams falls in the 0.1~30THz band. After the beam shape is optimized by the first deformable mirror and the residual laser is removed by the first filter, the beam is incident on the first DAST crystal 56 for difference frequency action. Finally, the converging assembly composed of a convex lens, germanium plate 57 and off-axis parabolic mirror 58 accurately focuses the terahertz signal to the Pb color center 12 position in diamond. The other laser beam passes through the third KTP crystal 60 at a fixed angle to generate a laser of a fixed frequency and enters the detector 62 for calculating the terahertz signal value.

[0045] In an optional embodiment, the diamond can be type IIa single-crystal diamond with an impurity content ≤5ppm; and Pb element is implanted into the diamond using ion implantation technology, wherein the implantation dose is greater than or equal to 1×10⁻⁶. 8 ion / cm 2 Vacuum degree greater than or equal to 1×10 -3 Pa.

[0046] In practical applications, diamond is annealed under the following conditions: annealing temperature ≥ 1000℃; annealing time ≥ 1 hour; annealing vacuum degree ≥ 1×10⁻⁶. -4 Pa.

[0047] This invention relates to a terahertz signal detection fluorescence system based on diamond color centers. Utilizing the quantum optical properties of Pb color center 12 in diamond, the terahertz signal is converted into a change in fluorescence polarization state. Specifically, terahertz radiation modulates the local phonon mode population of Pb color center 12, thereby altering its electronic ground state energy level splitting state. This results in an asymmetric change in the radiative transition probabilities of the C and D peaks. The relevant information can be obtained by monitoring the shift in fluorescence intensity. Based on a dual-path collaborative working mode, the terahertz signal generation optical path and the phonon signal detection optical path share the same 532nm laser source. By employing beam splitting technology, energy is rationally allocated and time synchronization between the two optical paths is achieved, effectively avoiding errors introduced by fluctuations in the external light source. The Wollaston prism 31 and the balanced detector 33 are used in combination to give the system terahertz electric field direction resolution capability. This combination can efficiently separate mutually perpendicular C and D peak signals with different contents (i.e., signal 1 and signal 2), improving the accuracy and reliability of signal detection. The 100x objective lens with 24-fold focusing achieves nanometer-level spatial resolution (spot diameter ≤1μm), and the balanced detector with a bandwidth of 33~100MHz supports nanosecond response, meeting the requirements for real-time monitoring of dynamic terahertz signals.

[0048] Finally, it should be noted that the terms "parallel" and "perpendicular" in the embodiments of this invention should not be strictly limited to a geometric sense. At least manufacturing and installation errors should be considered. For example, an error of ±10° should be within the protection range of the embodiments of this invention. The above embodiments are only used to illustrate the technical solutions of this invention, and not to limit it. Although the invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this invention.

Claims

1. A terahertz signal detection fluorescence system based on diamond color centers, characterized in that, include: A stage, wherein the stage is equipped with a diamond; A terahertz signal generation optical path is used to generate a frequency-tunable terahertz signal and act on the Pb color center of the diamond. The phonon signal detection optical path includes a fluorescence detection module, a demodulation module, and a signal processing module. The fluorescence detection module is used to apply the generated laser to the Pb color center of the diamond to generate a mixed fluorescence signal. The demodulation module is used to separate the mixed fluorescence signal to obtain two light signals, determine the intensity difference based on the two light signals, and output a corresponding electrical signal based on the intensity difference. The signal processing module is used to determine the value of the terahertz signal based on the electrical signal.

2. The terahertz signal detection fluorescence system based on diamond color centers according to claim 1, characterized in that, The two optical signals include two first optical signals and two second optical signals. Determining the intensity difference based on the two optical signals includes: The intensity difference is determined based on the two first optical signals and the two second optical signals; wherein the two first optical signals correspond to the terahertz signal acting on the Pb color center of the diamond, and the two second optical signals correspond to the terahertz signal not acting on the Pb color center of the diamond.

3. The terahertz signal detection fluorescence system based on diamond color centers according to claim 1, characterized in that, The fluorescence detection module includes a first laser, a beam splitter, an objective lens, a first lens, a pinhole space filter, a bandpass filter, and a Glan Taylor prism. The objective lens, the beam splitter, the pinhole space filter, the first lens, the bandpass filter, and the Glan Taylor prism are arranged in sequence. The laser output from the first laser passes through the beam splitter and the objective lens in sequence and acts on the Pb color center of the diamond.

4. The terahertz signal detection fluorescence system based on diamond color centers according to claim 3, characterized in that, The terahertz signal generating optical path includes a second laser, the first laser outputs a first laser with a first wavelength, and the second laser outputs a second laser with a second wavelength, wherein the first wavelength is equal to the second wavelength.

5. The terahertz signal detection fluorescence system based on diamond color centers according to claim 1, characterized in that, The demodulation module includes a Wollaston prism, a mirror group, and a balanced detector arranged in sequence. The Wollaston prism is used to separate the mixed fluorescence signal to obtain two light signals. The two light signals are reflected by the mirror group and enter the balanced detector. The balanced detector determines the intensity difference based on the two light signals and outputs a corresponding electrical signal based on the intensity difference.

6. The terahertz signal detection fluorescence system based on diamond color centers according to claim 5, characterized in that, The beam splitting angle of the Wollaston prism is 15° ± 0.5°, and the path difference between the two light signals is less than or equal to 5 μm; and / or, The common-mode rejection ratio of the balanced detector is greater than or equal to 80dB, and the bandwidth is greater than or equal to 1MHz.

7. The terahertz signal detection fluorescence system based on diamond color centers according to claim 1, characterized in that, The terahertz signal generation optical path includes a main terahertz signal generation path and a terahertz signal correction branch. The main terahertz signal generation path is used to generate a frequency-adjustable terahertz signal, and the terahertz signal correction branch is used to determine the value of the terahertz signal.

8. The terahertz signal detection fluorescence system based on diamond color centers according to claim 7, characterized in that, The frequency range of the terahertz signal is 0.1~30THz.

9. The terahertz signal detection fluorescence system based on diamond color centers according to claim 1, characterized in that, The diamond is a type IIa single-crystal diamond, and Pb element is implanted into the diamond using ion implantation technology, wherein the implantation dose is greater than or equal to 1 × 10⁻⁶. 8 ion / cm 2 .

10. The terahertz signal detection fluorescence system based on diamond color centers according to claim 9, characterized in that, The diamond is subjected to an annealing operation, wherein the annealing temperature is greater than or equal to 1000℃; the annealing time is greater than or equal to 1 hour; and the annealing vacuum degree is greater than or equal to 1×10⁻⁶. -4 Pa.

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