- 标题
- 摘要
- 关键词
- 实验方案
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Terahertz topological photonics for on-chip communication
摘要： The realization of integrated, low-cost and efficient solutions for high-speed, on-chip communication requires terahertz-frequency waveguides and has great potential for information and communication technologies, including sixth-generation (6G) wireless communication, terahertz integrated circuits, and interconnects for intrachip and interchip communication. However, conventional approaches to terahertz waveguiding suffer from sensitivity to defects and sharp bends. Here, building on the topological phase of light, we experimentally demonstrate robust terahertz topological valley transport through several sharp bends on the all-silicon chip. The valley kink states are excellent information carriers owing to their robustness, single-mode propagation and linear dispersion. By leveraging such states, we demonstrate error-free communication through a highly twisted domain wall at an unprecedented data transfer rate (exceeding ten gigabits per second) that enables real-time transmission of uncompressed 4K high-definition video (that is, with a horizontal display resolution of approximately 4,000 pixels). Terahertz communication with topological devices opens a route towards terabit-per-second datalinks that could enable artificial intelligence and cloud-based technologies, including autonomous driving, healthcare, precision manufacturing and holographic communication.
关键词： topological photonics,silicon chip,valley kink states,on-chip communication,terahertz
更新于2025-09-19 17:13:59
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A highly sensitive and tunable plasmonic sensor based on a graphene tubular resonator
摘要： A novel configuration of dynamically tunable surface plasmon polaritons (SPPs) is proposed based on two waveguides and one nanotube graphene in the terahertz range and is numerically investigated as a highly sensitive sensor. In the proposed structure, the two graphene waveguides coupled to the nanotube have two plasmonic modes which have two high sensitivities in different frequencies. The results show that in this structure, the sensitivity values are measured as the order of 7714 nm/RIU inside the tube and 18500 nm/RIU in the total environment. The sensitivity value in the total environment is at least 148.3% larger than those of previously reported waveguides which is an excellent result. This graphene waveguide sensor can have an important practical application in biosensors and lab-on-chip systems.
关键词： Nanotube,Graphene,Waveguide,Sensor,Terahertz
更新于2025-09-19 17:13:59
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Graphene based plasma-wave devices for terahertz applications
摘要： Unique properties of graphene are combined to enable graphene plasmonic devices that could revolutionize the terahertz (THz) electronic technology. A high value of the carrier mobility allows us to excite resonant plasma waves. The graphene bipolar nature allows for different mechanisms of plasma wave excitation. Graphene bilayer and multilayer structures make possible improved THz device configurations. The ability of graphene to form a high quality heterostructure with h-BN, black phosphorus, and other materials systems supports advanced heterostructure devices comprised of the best properties of graphene and other emerging materials. In particular, using black phosphorus compounds for cooling electron–hole plasma in graphene could dramatically improve the conditions for THz lasing. High optical phonon energy allows for reaching higher plasma frequencies that are supported by high sheet carrier densities in graphene. Recent improvements in graphene technology combined with a better understanding of the device physics of graphene THz plasmonics and graphene plasmonic device designs hold promise to make graphene THz plasmonic technology one of the key graphene applications. Commercialization of plasmonic graphene technology is facing the same challenges as other graphene applications, which have difficulties in producing uniform large graphene layers, bilayers, and heterostructures of high quality and making good low resistance stable Ohmic contacts. The time projection for large scale graphene electronic device applications now extends into the 2030s. However, emerging graphene mass production technologies might bring commercial applications of the graphene plasmonic terahertz technology closer.
关键词： heterostructures,graphene,black phosphorus,Ohmic contacts,plasma waves,THz technology,terahertz,plasmonic devices,optical phonon energy,carrier mobility
更新于2025-09-19 17:13:59
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Continuous-wave 6-dB-squeezed light with 2.5-THz-bandwidth from single-mode PPLN waveguide
摘要： Terahertz (THz)-bandwidth continuous-wave (CW) squeezed light is essential for integrating quantum processors with time-domain multiplexing (TDM) by using optical delay line interferometers. Here, we utilize a single-pass optical parametric amplifier (OPA) based on a single-spatial-mode periodically poled ZnO:LiNbO3 waveguide, which is directly bonded onto a LiTaO3 substrate. The single-pass OPA allows THz bandwidth, and the absence of higher-order spatial modes in the single-spatial-mode structure helps avoid degradation of squeezing. In addition, the directly bonded ZnO-doped waveguide has durability for high-power pump and shows small photorefractive damage. Using this waveguide, we observe CW 6.3-dB squeezing at 20-MHz sideband by balanced homodyne detection. This is the first realization of CW squeezing with a single-pass OPA at a level exceeding 4.5 dB, which is required for the generation of a two-dimensional cluster state. Furthermore, the squeezed light shows 2.5-THz spectral bandwidth. The squeezed light will lead to the development of a high-speed on-chip quantum processor using TDM with a centimeter-order optical delay line.
关键词： terahertz-bandwidth,quantum information processing,squeezed light,continuous-wave,single-mode PPLN waveguide
更新于2025-09-19 17:13:59
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Narrowband Perfect Terahertz Absorber Based on Polar-dielectrics Metasurface
摘要： We theoretically propose a narrowband perfect absorber metasurface (PAMS) based on a silver surface phonon polaritons in the terahertz range. The PAMS has biarc on the top, a thin polar-dielectric in the middle and a silver layer at the bottom. The phonon polaritons have excited at the interface between the silver biarc and the polar dielectric and have enhanced the absorption of the PAMS. The absorption peak is at 36.813μm and the full width half maximum (FWHM) near 36nm and is independent of the polarization and incidence angle. The electric fields are located at the split of the biarc silver layer and the quality factor (Q) is 1150. The FWHM decreases with the decreasing of split width. When the thickness of bottom layer larger than 50nm, the narrow band and high absorption are insensitive of the thickness of those layer. The designed absorber may have useful applications in terahertz spectrum such as energy harvesting, thermal emitter, and sensing.
关键词： Polar-dielectrics,Terahertz,Metasurface,Narrowband Perfect Absorber
更新于2025-09-19 17:13:59
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Electromagnetic Wave Absorbers (Detailed Theories and Applications) || Absorber Characteristic Control by Equivalent Transformation Method of Material Constants
摘要： As mentioned in the previous chapters, demands for various EM-wave absorbers are rapidly increasing along with the trends toward complicated electromagnetic environments and the development of higher frequency communication equipment. Generally, it has been considered highly difficult to produce new EM-wave absorbers having a desired absorbing frequency and an absorbing characteristic. One reason for this is that realizing an optimum material constant satisfying the required characteristics becomes difficult when manufacturing an EM-wave absorber. That is, in the conventional method, it often becomes difficult to freely control parameters such as the mixing ratio of the EM-wave absorber’s raw materials, the firing temperature, the pressure, and the material compositions to realize the appropriate absorber. Furthermore, the problems of accurately measuring material constants and maintaining the accuracy of component sizes become important to the EM-wave absorber in high-frequency use, particularly in the millimeter or terahertz band.
关键词： equivalent transformation method of material constants (ETMMC),EM-wave absorbers,millimeter wave,terahertz band,high-frequency communication
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 2nd British and Irish Conference on Optics and Photonics (BICOP) - London, United Kingdom (2019.12.11-2019.12.13)] 2019 IEEE 2nd British and Irish Conference on Optics and Photonics (BICOP) - Oligofluorene Truxene Laser Sensor: Towards Bacteria Growth Detection
摘要： We demonstrate the performance enhancement of field-effect transistor (FET)-based plasmonic terahertz (THz) detector with monolithic integrated antenna in low-impedance regime and report the experimental results of Si MOSFET impedance in THz regime using 0.2-THz measurement system. By designing FET with low-impedance ranges (<1 kΩ) and integrating antennas with impedances of 50 and 100 Ω, we found that our low-impedance MOSFETs have the input impedance criterion of 50 Ω at 0.2 THz and the MOSFETs with thinner gate oxide show the highly enhanced plasmonic photoresponses at 50-Ω antenna by 325 times from the result of the detector without antenna.
关键词： impedance,plasmonic,detector,photoresponse,MOSFET,terahertz
更新于2025-09-19 17:13:59
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Dielectrics for Terahertz Metasurfaces: Material Selection and Fabrication Techniques
摘要： Manipulation of terahertz radiation opens new opportunities that underpin application areas in communication, security, material sensing, and characterization. Metasurfaces employed for terahertz manipulation of phase, amplitude, or polarization of terahertz waves have limitations in radiation efficiency which is attributed to losses in the materials constituting the devices. Metallic resonators-based terahertz devices suffer from high ohmic losses, while dielectric substrates and spacers with high relative permittivity and loss tangent also reduce bandwidth and efficiency. To overcome these issues, a proper choice of low loss and low relative permittivity dielectric layers and substrates can improve field confinement and reduce dissipation. Alternatively, replacing metallic resonators with a moderate relative permittivity dielectric material that supports cavity mode resonances also reduces dissipation due to the absence of conduction current. Herein, an overview of dielectric materials employed as spacers and dielectric resonators is provided, and the fabrication methods employed to realize these devices at the terahertz frequency range are also presented. Material selection guidelines, material-specific and application-specific fabrication quality metrics are outlined, and new techniques are proposed.
关键词： metasurfaces,dielectric spacers,dielectric resonators,low loss dielectrics,terahertz devices
更新于2025-09-19 17:13:59
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Guided‐Mode Resonances in All‐Dielectric Terahertz Metasurfaces
摘要： Coupling of diffracted waves in gratings with the waveguide modes gives rise to the guided mode resonances (GMRs). The GMRs provide designer linewidth and resonance intensity amidst a broad background, and thus have been widely used for numerous applications in visible and infrared spectral regions. Here, terahertz GMRs are demonstrated in low-loss, all-dielectric metasurfaces, which are periodic square lattices of silicon cuboids on quartz substrates. The silicon cuboid lattice simultaneously acts as a diffraction grating and an in-plane slab waveguide, thereby resulting in the formation of terahertz GMRs. At oblique incidence, two distinct frequency detuned GMRs are observed. The frequency difference between these two GMRs increases at larger angle of incidence. However, extremely small angle of incidence causes destructive interference between these counter-propagating GMRs that leads to a nonradiative symmetry-protected bound state in the continuum. GMRs in all-dielectric silicon metasurfaces can have potential applications in the realization of efficient terahertz devices such as high-Q transmission filters with angular spectral selectivity, ultrafast modulators, and free-space couplers.
关键词： guided-mode resonance,bound states in the continuum,all-dielectric metasurface,terahertz
更新于2025-09-19 17:13:59
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Simultaneous determination of organic distribution and content in oil shale by terahertz imaging
摘要： Organics in oil shale plays a significant role in the generation and production of oil-gas. Visualizing the content and distribution of organics in the reservoir is the key objective of unconventional resource research. Here in this study, we demonstrate the application of terahertz (THz) imaging to measure the dielectric properties of oil shale from Huadian and Beipiao with different oil yields. The heterogeneous distribution of organics on the oil shale surface were evaluated by THz amplitude images, with the existence of kerogen-rich and kerogen-poor areas identified by different colors. Meanwhile, average refractive index of the samples were plotted with the oil yield, revealing a negative correlation between them. Our results prove that the THz spectroscopy can not only provide a promising technique to visualize the organic distribution but also a convenient means for quantitative analysis of the organic content in oil shale.
关键词： Terahertz imaging,Organics distribution,Oil shale,Oil yield
更新于2025-09-19 17:13:59