11 results about "Thz waves" patented technology

The invention relates to the technical field of multifunctional composite materials, and discloses composite hydrogel with a two-stage pore structure as well as a preparation method and application of the composite hydrogel. The composite hydrogel with the two-stage pore structure is prepared by carrying out synergistic pre-assembly on liquid metal nanoparticles and MXene nanosheets and then carrying out in-situ polymerization with an acrylic monomer; a two-stage pore structure which is formed in situ in one step through polymerization heat release is arranged in the porous material. In the hydrogel disclosed by the invention, the liquid metal exerts multiple functions of hydrophobic modification, pore forming and electric conduction, and generates a synergistic enhancement effect of '1 + 1gt, 2' with the MXene; through the synergistic effect of a hydrophobic area introduced by the liquid metal and a two-stage pore structure, the swelling resistance of the hydrogel is fundamentally improved, so that the hydrogel can adapt to harsh water environments and chemical environments. Based on the synergistic effect, the composite hydrogel with the two-stage pore structure has excellent broadband electromagnetic shielding performance (covering GHz and THz wave bands), infrared thermal camouflage capability, ultraviolet shielding function and long-term anti-swelling stability in a harsh liquid phase environment.

The invention belongs to the technical field of photon detection, and particularly relates to a frequency up-conversion THz wave-based multi-photon detection system and method, and the system comprises a pump light source unit, a beam combiner, a nonlinear crystal, a light splitting unit, a space photon counting detector, a light shaping device, and a controller. According to the technology, THz up-conversion signals are converted from single time domain detection to time and space domain coincidence detection, meanwhile, by means of the spatial resolving power of the multi-photon detector, when time-synchronous fluorescence is achieved, the technology can be combined with the space light gate technology to execute detection in a light gate where the signals are expected to arrive, and therefore fluorescence components are restrained. Finally, effective detection of THz up-conversion signals with spontaneous parametric up-conversion fluorescence can be realized.

The application aims to provide a kind of optimized cascade difference frequency terahertz wave radiation source, which can enhance the intensity of terahertz wave and improve the energy conversion efficiency of terahertz wave.Compared with the traditional cascade difference frequency needing two pump sources, the scheme only needs one pump source, the polarization period of AFB-KTP crystal determines the wavelength of generated signal light and idler light, and through the setting of the polarization period of AFB-KTP crystal, the purpose of different frequency THz wave tuning is achieved.Through the setting of the non-polarization period of APPLN crystal, the signal light photon is repeatedly transferred to high-order Stokes light photon, and the conversion efficiency of terahertz wave is improved.

The application discloses a graphene-VO2-based terahertz ultra-wideband adjustable wave absorber and belongs to the technical field of terahertz technology, comprising, from top to bottom, a phase change material layer, a first dielectric layer, a graphene layer, a second dielectric layer and a reflection layer; the phase change material layer comprises a plurality of periodically arrayed VO2 umbrella-shaped patches; each VO2 umbrella-shaped patch is a regular octagon structure composed of eight congruent isosceles triangles; there are gaps between adjacent isosceles triangles; and adjacent VO2 umbrella-shaped patches are not connected with each other. The umbrella-shaped VO2 patches arranged in an array are combined with the graphene layer to realize ultra-wideband wave absorption in a 3-10 THz wave band, and the absorption rate is kept above 90%; and by respectively controlling the conductivity of the phase change material layer and the Fermi level of the graphene layer, the wave absorber presents different working states and has the characteristics of functional diversity.

This invention discloses a coupled microstrip antenna element, a determination method thereof, and a coupled antenna photoconductive detector, relating to the field of terahertz technology. The antenna element mainly comprises: an I-shaped antenna and two microstrip antennas with identical structural parameters; an opening is provided at the center of the middle arm of the I-shaped antenna; the two microstrip antennas are symmetrically placed on both sides of the middle arm; the microstrip antenna includes multiple groove structures, with the opening of each groove structure facing the middle arm; the structural parameters of the microstrip antenna include at least the number of groove structures, the groove period, the groove width, and the groove depth; through the resonant coupling effect between the microstrip antenna and the I-shaped antenna, the incident THz wave is localized to the central opening of the I-shaped antenna, enhancing the local electric field strength of the THz wave, thereby improving the detection sensitivity of the coupled antenna photoconductive detector.

One embodiment includes a terahertz (THz) optoelectronic device configured to generate and detect THz waves at frequencies ranging from 40 GHz to 10 THz through photomixing when illuminated with an optical beam with more than one wavelength is provided. The device comprises a substrate composed of quantum well layers embedded in an intrinsic region of a PIN photodiode.

The invention discloses a graphene terahertz metasurface sensor and application thereof in pesticide residue detection, and relates to the technical field of sensors and detection. The graphene terahertz metasurface sensor comprises a substrate, a metasurface layer, a graphene film and an aptamer layer. The invention further provides application of the graphene terahertz metasurface sensor in pesticide residue detection. The metasurface layer is composed of the asymmetric metal wire array, the metasurface layer is placed in a light path of a transmission-type THz time-domain spectroscopy system, under the condition that the polarization direction of incident waves is along the x axis, the structure can generate extremely strong local electric field enhancement, and when the metasurface layer is used for detecting pesticide molecules, the detection sensitivity is greatly improved. The interaction between THz waves and pesticide molecules to be detected is obviously enhanced, so that the purpose of trace sensing of a target object is achieved. In addition, graphene is utilized and the metasurface of the aptamer layer is modified, so that the detection sensitivity and specificity are improved.

The invention belongs to the field of wave-absorbing materials, and discloses a terahertz wave-absorbing fabric and a preparation method thereof. The terahertz wave-absorbing fabric comprises a conductive fiber porous array layer, a middle dielectric layer and a dense conductive cloth layer, the middle dielectric layer is arranged on one side of the conductive cloth layer; and the conductive fiber porous array layer is arranged on one side, far away from the conductive cloth layer, of the dielectric layer to form a three-layer composite wave-absorbing structure. According to the terahertz wave-absorbing fabric, the middle dielectric layer arranged on one side of the conductive cloth layer and the conductive fiber porous array layer arranged on the side, away from the conductive cloth layer, of the middle dielectric layer form a three-layer composite wave-absorbing structure, so that broadband, efficient and flexible wave absorption of the 0.1-2 THz wave band is achieved; the application requirements of wearing, stealth protection, electromagnetic compatibility and the like are met, and the absorptivity in a 50% frequency band reaches 0.9; and the fabric is distinct in structural hierarchy, easy to prepare, simple in structure and low in cost, and can be realized by utilizing a textile technology.

The invention belongs to the technical field of photon detection, and particularly relates to a THz photon counting detection system based on cascade frequency up-conversion, which comprises a first pump light source, a second pump light source, a first beam combiner, a first nonlinear crystal, a light splitting unit, a second beam combiner, a second nonlinear crystal, a light shaping device, a space photon counting detector, a time gating and a space gating. The first nonlinear crystal upconverts THz wave frequency into a near-infrared light signal and generates spontaneous parametric upconversion fluorescence noise consistent with time, space and spectrum characteristics of the signal, and the signal and the noise are mixed, so that the unit type SPD fails. According to the technology, the cascade frequency of a near-infrared signal is up-converted to visible light, signal-noise photons are spatially separated through a light shaping device, and photon counting detection of the signal is realized by combining a space photon counting detector with a mature visible light wave band with space-time coincidence measurement, so that room-temperature photon counting detection of THz waves is realized.

This invention discloses a graphene terahertz metasurface sensor and its application in pesticide residue detection, relating to the fields of sensor and detection technology. The graphene terahertz metasurface sensor comprises a substrate, a metasurface layer, a graphene film, and an aptamer layer. This invention also provides the application of the graphene terahertz metasurface sensor in pesticide residue detection. The metasurface layer of this invention is composed of an asymmetric metal wire array. When placed in the optical path of a transmission THz time-domain spectroscopy system, with the incident wave polarization direction along the x-axis, the structure itself can generate a very strong local electric field enhancement. When used to detect pesticide molecules, the interaction between the THz wave and the pesticide molecules to be measured is significantly enhanced, thereby achieving trace sensing of the target analyte. Furthermore, this invention utilizes graphene and modifies the aptamer layer metasurface to improve the sensitivity and specificity of detection.