Monday, November 18, 2019
Abstract-Graphene-based crack lithography for high-throughput fabrication of terahertz metamaterials
Sejeong Won, Hyun-June Jung, Dasom Kim, Sang-Hun Lee, DoVan Lam, Hyeon-Don Kim, Kwang-Seop Kim, Seung-Mo Lee, Minah Seo, Dai-Sik Kim, Hak-Joo Lee, Jae-Hyun Kim,
Terahertz (THz) nanoantennas have significant potential for versatile applications in THz spectroscopy because of their capability for strong electromagnetic field localization. Electron-beam lithography or focused ion beam machining is typically employed to fabricate nanoantenna structures. These nanolithography methods present limitations in the widespread utilization of THz nanoantennas because of their high cost and low productivity. In this work, we proposed graphene-based crack lithography as a high throughput fabrication method for nanoantenna structures. A double-layer graphene interface was introduced to enable independent control of the nanoantenna dimensions and provide graphene-based nanoantenna structures. We analyzed the underlying mechanism of graphene-based cracking and developed an analytical model governing the geometric parameters of the fabricated nanostructures. As a vital application of the fabricated nanoantenna structures, we demonstrated the highly sensitive detection of -Glucose molecules. Graphene-based crack lithography can provide a cost-effective method for generating nanoantenna structures with the desired characteristics and can accelerate the development of practical applications of electromagnetic metamaterials.
Sunday, November 17, 2019
Anton Zaitsev, ,Alexander Grebenchukov, Mikhail Khodzitsky,
The tunable terahertz (THz) Fano-resonant filter based on hybrid metal-graphene metamaterial was proposed. The optical parameters of metasurface with unit cell in the form of a cross-shaped graphene sheet in the center of a square gold ring were simulated by the finite element method using a surface conductivity model of a graphene monolayer. The narrowband modulation of the transmission by varying the Fermi level of the graphene and the position of graphene cross inside the metal ring was demonstrated. Simulation results were well explained theoretically using a three-coupled oscillator model. The proposed device can be used as a narrowband filter in wireless THz communication systems and sensing applications.
Abstract-Ferromagnetic resonance isolator based on a photonic crystal structure with terahertz vortices
Gianni Portela, Victor Dmitriev, Daimam Zimmer,
A new terahertz isolator based on the ferromagnetic resonance effect is suggested and analyzed. A two-dimensional photonic crystal consisting of a square lattice of gallium arsenide rods has been employed in the design of the device. Incident electromagnetic waves interact with one magnetized ferrite rod and two stubs inserted in the photonic crystal structure, generating a vortex-like field profile in the ferrite rod. Electromagnetic signals propagating in the forward direction are transmitted with low insertion losses, while their propagation in the backward direction is not allowed due to the high losses of the ferrite rod operating at the ferromagnetic resonance regime. Computational simulations show that the operating bandwidth is equal to 0.87 GHz around the central frequency 106.6 GHz. In this frequency band, the insertion losses are lower than − 1.68 dB, the reflection levels are better than − 16 dB, and the isolation levels are greater than − 15 dB.
Saturday, November 16, 2019
Anqi Yu, Xuguang Guo, Yiming Zhu, Alexey V. Balakin, Alexander P. Shkurinov,
|(a) The proposed split T-shape metal/dielectric/graphene structure. (b) The top view of the proposed structure.|
Mingrui Yuan, Yanfeng Li, Yongchang Lu, Ying Zhang, Ziying Zhang, Xueqian Zhang, Xixiang Zhang, Jiaguang Hah, Weili Zhang
THz plasmonic waveguides ...
For terahertz (THz) integrated systems, an intersection between waveguides is inevitable and is often accompanied by considerable crosstalk and loss. Here, we propose and experimentally demonstrate a novel type of crossing with a footprint less than 0.2 × 0.2 mm2 for THz surface plasmon polariton waveguiding. With an optimized crossover structure, the measured loss of the intersection is as low as 0.89 dB/crossing, and the crosstalk is less than −19.06 dB/crossing at 0.55 THz. The proposed crossing structure is compact and has low loss and crosstalk within a broad band, which will pave the way for a wide range of new applications for THz integrated systems.
Friday, November 15, 2019
Abstract-On the effect of third-order dispersion on phase-matched terahertz generation via interfering chirped pulses
Spencer W. Jolly, Frederike Ahr, Koustuban Ravi, Nicholas H. Matlis, Franz X. Kärtner, and Andreas R. Maier