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Graphene supports surface plasmon polaritons with comparatively slow propagation velocities in the THz region, which becomes increasingly interesting for future communication technologies. This ability can be used to realize compact…

By exploiting singular spatial modulations of the graphene conductivity, we design a broadband, tunable THz absorber whose efficiency approaches the theoretical upper bound for a wide absorption band with a fractional bandwidth of 185\%.…

Mesoscale and Nanoscale Physics · Physics 2018-10-25 Emanuele Galiffi , John Pendry , Paloma Arroyo Huidobro

In spintronic terahertz emitters, THz radiation is generated by exciting an ultrafast spin current through femtosecond laser excitation of a ferromagnetic-nonmagnetic metallic heterostructure. Although an extensive phenomenological…

Materials Science · Physics 2024-11-22 Francesco Foggetti , Peter M. Oppeneer

The propagation of radio frequency (RF) waves in tokamaks can be affected by filamentary structures present in the edge plasma. The waves are reflected, refracted, and diffracted, leading to a decrease in efficiency of heating and/or…

Plasma Physics · Physics 2021-12-22 Spyridon I. Valvis , Abhay K. Ram , Kyriakos Hizanidis

The effects of turbulence intensity and turbulence region on the distribution of femtosecond laser filaments are experimentally elaborated. Through the ultrasonic signals emitted by the filaments, and it is observed that increasing…

Spintronic THz emitters (STE) are efficient THz sources constructed using thin heavy-metal (HM) and ferromagnetic-metal (FM) layers. To improve the performance of the STE, different structuring methods (trilayers, stacked bilayers) have…

Materials Science · Physics 2023-04-19 Yingshu Yang , Stefano Dal Forno , Marco Battiato

We report on terahertz emission from a single layer ferromagnet which involves the generation of backflow nonthermal charge current from the ferromagnet/dielectric interface by femtosecond laser excitation and subsequent conversion of the…

Applied Physics · Physics 2020-06-15 Qi Zhang , Ziyan Luo , Hong Li , Yumeng Yang , Xinhai Zhang , Yihong Wu

Phased arrays are crucial in various technologies, such as radar and wireless communications, due to their ability to precisely control and steer electromagnetic waves. This precise control improves signal processing and enhances imaging…

This article focuses on the near-field effect in terahertz (THz) communications and sensing systems. By equipping with extremely large-scale antenna arrays (ELAAs), the near-field region in THz systems can be possibly extended to hundreds…

Information Theory · Computer Science 2023-06-19 Zhaolin Wang , Xidong Mu , Yuanwei Liu

Terahertz (THz) wireless communications have the potential to realize ultra-high-speed and secure data transfer with miniaturized devices for unmanned aerial vehicle (UAV) communications. Existing THz channel models for aerial scenarios…

Signal Processing · Electrical Eng. & Systems 2023-05-16 Weijun Gao , Chong Han , Zhi Chen

The use of the THz frequency domain in future network generations offers an unparalleled level of capacity, which can enhance innovative applications in wireless communication, analytics, and imaging. Communication technologies rely on…

A full (2$\pi$) phase modulation is critical for efficient wavefront manipulation. In this article, a metasurface based on graphene long/short-strip resonators is used to implement a dynamic 2$\pi$ phase modulation by applying different…

Optics · Physics 2016-01-22 Liming Liu , Yair Zarate , Haroldo T. Hattori

THz time domain spectroscopy is a powerful technique enabling the investigation of different materials in the far-infrared frequency range. Even if nowadays this technique is well established, its application to very thin films remains…

Instrumentation and Detectors · Physics 2024-06-07 A. Taschin , P. Bartolini , J. Tasseva , R. Torre

Terahertz (THz) frequencies are important for next generation wireless systems due to the advantages in terms of large available bandwidths. On the other hand, the limited range due to high attenuation in these frequencies can be overcome…

Signal Processing · Electrical Eng. & Systems 2024-05-31 Hasan Nayir , Erhan Karakoca , Güneş Karabulut Kurt , Ali Görçin

Coherent radiation with frequencies ranging from 0.3 to 30 THz has recently become accessible by femtosecond laser technology. Terahertz (THz) waves have already found many applications in spectroscopy and imaging, and they can be…

Adoption of terahertz technologies is hindered by the lack of cost-effective THz sources. Here we demonstrate a fundamentally new way to generate and control THz radiation, via spatio-temporal emissivity modulation. By patterning the…

Using high-resolution, two-dimensional particle-in-cell simulations, we investigate numerically the mechanisms of terahertz (THz) emissions in submicron-thick carbon solid foils driven by ultraintense ($\sim 10^{20}\,\rm W\,cm^{-2}$),…

Plasma Physics · Physics 2020-07-10 J. Déchard , X. Davoine , L. Gremillet , L. Bergé

We propose a terahertz radiation source based on the excitation of plasma resonances in graphene structures by means of mixing two NIR laser signals with a THz difference frequency. The process is the photo-thermo-electric effect which has…

Mesoscale and Nanoscale Physics · Physics 2014-02-07 Don Schmadel , Gregory S. Jenkins , H. Dennis Drew

In this work we developed an extension to the Transfer Matrix method (TMM) to include a current source term, with the aim of describing both the transmission and emission of THz pulses in spintronics THz emitters. The TMM with source is…

Applied Physics · Physics 2021-11-01 Yingshu Yang , Stefano Dal Forno , Marco Battiato

The emission properties of terahertz(THz) photoconductive antenna (PCA) have been numerically studied by three-dimensional finite-difference-time-domain method based on the full-wave model. The dependence of the THz radiation on various…

Optics · Physics 2014-07-11 Jitao Zhang