English
Related papers

Related papers: Superluminal propagation and broadband omnidirecti…

200 papers

A coherent, short-length reference arm reflectometer, which utilizes a 76-MHz repetition rate mode-locked fiber laser, was investigated experimentally for long fiber links (> 10 km). The reflectometer combines the advantages of optical…

Instrumentation and Detectors · Physics 2019-08-05 P. Cho , Y. Leng , P. Petruzzi , M. Morris , G. Baumgartner , J. Goldhar

Terahertz frequencies are an untapped resource for providing high-speed short-range communications. As a result, it is of interest to study the propagation characteristics of terahertz waves and to develop channel models. In previous work…

Signal Processing · Electrical Eng. & Systems 2022-10-17 Thanh Le , Ha Tran , Suresh Singh

In this paper, we investigate the propagation of the light pulse reflected from the layer system with a graphene layer. We show a tunable transition between positive and negative group delay of the optical pulse reflection in such a layered…

Optics · Physics 2017-10-11 Lin Wang , Li-Gang Wang , M. Suhail Zubairy

Lenses are typically based on refractive index profiles derived from the geometric approximation of high-frequency waves, yet the critical issue of impedance mismatch is often neglected. Mismatched devices suffer from unwanted reflections…

Optics · Physics 2025-06-18 Sebastiano Cominelli

We predict a new branch of surface Josephson plasma waves (SJPWs) in layered superconductors for frequencies higher than the Josephson plasma frequency. In this frequency range, the permittivity tensor components along and transverse to the…

Superconductivity · Physics 2015-05-14 V. A. Golick , D. V. Kadygrob , V. A. Yampol'skii , A. L. Rakhmanov , B. A. Ivanov , Franco Nori

We study the reflection of polarized optical pulses from resonant photonic structures formed by periodic, Fibonacci, and gradient sequences of quantum wells. The form and polarization of the reflected pulse are shown to be determined by the…

Mesoscale and Nanoscale Physics · Physics 2015-06-11 A. V. Poshakinskiy , A. N. Poddubny , S. A. Tarasenko

Receiver protectors (RPs) shield sensitive electronics from high-power incoming signals that might damage them. Typical RP schemes range from simple fusing and PIN diodes, to superconducting circuits and plasma cells - each having a variety…

Reflectarrays composed of resonant microstrip gold patches on a dielectric substrate are demonstrated for operation at terahertz frequencies. Based on the relation between the patch size and the reflection phase, a progressive phase…

An arbitrarily-shaped optical potential on a discrete photonic lattice, which transversely drifts at a speed larger than the maximum one allowed by the light cone of the lattice band, becomes reflectionless. Such an intriguing result, which…

Optics · Physics 2017-10-18 Stefano Longhi

We demonstrate a metamaterial that cannot be described by a single set of refractive-index and impedance values, even for fixed frequency and polarization. The metamaterial structure is a stack of dissimilar waveguides with subwavelength…

Propagation, transmission and reflection properties of linearly polarized plane waves and arbitrarily short electromagnetic pulses in one-dimensional dispersionless dielectric media possessing an arbitrary space-time dependence of the…

We investigate the spectral features of the emission from a superluminal polarization current whose distribution pattern rotates with an angular frequency $\omega$ and oscillates with an incommensurate frequency $\Omega >\omega$. This type…

Optics · Physics 2009-11-07 H. Ardavan , A. Ardavan , J. Singleton

Recently, the reconfigurable intelligent surface (RIS) technology has ushered in the prospect of control over the wireless propagation environment. By establishing alternative propagation paths for the transmitted signals, and by reflecting…

Signal Processing · Electrical Eng. & Systems 2025-11-18 Pedro H. C. de Souza , Luciano Mendes

Broadband and omnidirectional antireflection coating is a generally effective way to improve solar cell efficiency, because the destructive interference between the reflected and input waves could maximize transmission light in the…

A theoretical study of the resonance optical response of assemblies of oriented short (as compared to an optical wavelength) linear Frenkel chains is carried out using a two-level model. We show that both transmittivity and reflectivity of…

Chemical Physics · Physics 2015-06-26 E. Conejero Jarque , V. A. Malyshev

We use a state-of-the-art optimization algorithm combined with a careful methodology to find optimal anti-reflective coatings. Our results show that ultra thin structures (less than $300 \,nm$ thick) outperform much thicker gradual patterns…

Reflection at relativistically moving plasma mirrors is a well-known approach for frequency conversion as an alternative to nonlinear techniques. A key issue with plasma mirrors is the need for a high carrier concentration, of order 10^21…

As a means to control wireless propagation environments, the use of emerging and novel intelligent reflecting surfaces (IRS) is envisioned to enhance and broaden many applications in future wireless networks. This paper is concerned with a…

Signal Processing · Electrical Eng. & Systems 2020-03-23 Dian-Wu Yue , Ha H. Nguyen , Yu Sun

Spatially exponential distributions of material properties are ubiquitous in many natural and engineered systems, from the vertical distribution of the atmosphere to acoustic horns and anti-reflective coatings. These media seamlessly…

Applied Physics · Physics 2024-04-09 Sichao Qu , Min Yang , Tenglong Wu , Yunfei Xu , Nicholas Fang , Shuyu Chen

Ray tracing is widely employed to model the propagation of radio-frequency (RF) signal in complex environment. The modelling performance greatly depends on how accurately the target scene can be depicted, including the scene geometry and…

Computer Vision and Pattern Recognition · Computer Science 2025-01-07 Haifeng Jia , Xinyi Chen , Yichen Wei , Yifei Sun , Yibo Pi