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Related papers: Pushing the limits of negative group velocity

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This paper presents numerical simulations of dual-frequency second-order ultrasound field (SURF) reverberation suppression transmit-pulse complexes. Such propagation was previously studied in a homogeneous medium. Here instead the…

Medical Physics · Physics 2013-04-16 Sven Peter Nasholm , Bjørn A. J. Angelsen

One-dimensional defect photonic crystal (Bragg waveguide) is studied from the viewpoint of the slow light problem. The calculations are presented showing that in the TiO$_2$/SiO$_2$-based Bragg waveguide one can obtain the group index of…

Optics · Physics 2008-11-07 G. G. Kozlov , V. S. Zapasskii , V. V. Ovsyankin

Light springs are space-time beams that have a helical wavepacket. Due to this special property, light springs result into a rotating pulse when intercepting a plane lying orthogonal to their propagation direction. Associated to this, we…

Optical complex materials offer unprecedented opportunity to engineer fundamental band dispersion which enables novel optoelectronic functionality and devices. Exploration of photonic Dirac cone at the center of momentum space has inspired…

The traversal times for an electromagnetic pulse traversing a slab of dispersive and dissipative material with negative dielectric permittivity ($\epsilon$) and magnetic permeability ($\mu$) have been calculated by using the average flow of…

Materials Science · Physics 2008-12-05 Lipsa Nanda , S. Anantha Ramakrishna

Intelligent reflecting surface (IRS) is a promising technology for achieving high spectrum efficiency in future wireless networks by leveraging massive low-cost reflecting elements with each reflecting the incident signal with a proper…

Information Theory · Computer Science 2018-10-29 Qingqing Wu , Rui Zhang

Nonlinear pulse propagation in gas-filled waveguides has attracted substantial attention over the past decade, and a variety of capabilities have been reported. However, there is no prior report of spectral compression in gas-filled…

Optics · Physics 2026-03-24 Zegui Wang , Yi-Hao Chen , Yunlong Mo , Zaitian Dong , Wanhong Yin , Frank Wise , Wei Cao

Extremely anisotropic metal-dielectric multilayer metamaterials are designed to have the effective permittivity tensor of a transverse component (parallel to the interfaces of the multilayer) with zero real part and a longitudinal component…

Optics · Physics 2015-06-23 Lei Sun , Xiaodong Yang , Wei Wang , Jie Gao

Ultrafast electron diffraction (UED) is a powerful method for studying time-resolved structural changes. Currently, space charge induced temporal broadening prevents obtaining high brightness electron pulses with sub-100 fs durations…

Instrumentation and Detectors · Physics 2013-10-29 Yihua Wang , Nuh Gedik

We present the results of experiments performed on cold caesium in a pulsed sinusoidal optical potential created by counter-propagating laser beams having a small frequency difference in the laboratory frame. Since the atoms, which have…

Quantum Physics · Physics 2009-11-10 P. H. Jones , M. Goonasekera , H. E. Saunders-Singer , D. R. Meacher

Active reconfigurable intelligent surface (RIS) emerges as an effective technique to resist the double-fading attenuation of passive RIS. By embedding with power harvesting function, it further evolves to zero-power active RIS, which can…

Information Theory · Computer Science 2025-10-17 Xiao Zheng , Wenchi Cheng , Jingqing Wang , Zhuohui Yao , Jiangzhou Wang

The Poynting vector, energy density and energy velocity of light pulses propagating in anomalous dispersion medium (used in WKD-like experiments) are calculated. Results show that a negative energy density in the medium propagates along…

General Physics · Physics 2009-11-07 Chao-Guang Huang , Yuan-Zhong Zhang

The interaction of intense, ultra-short laser pulses with nanostructures offers promising avenues for spatiotemporal light control. While enhanced optical transmission through subwavelength apertures has been extensively studied in the…

Optics · Physics 2025-10-31 Xiaohui Gao

Intelligent reflecting surface (IRS) has been recognized as a powerful technology for boosting communication performance. To reduce manufacturing and control costs, it is preferable to consider discrete phase shifts (DPSs) for IRS, which…

Information Theory · Computer Science 2023-11-07 Guojie Hu , Qingqing Wu , Dognhui Xu , Kui Xu , Jiangbo Si , Yunlong Cai , Naofal Al-Dhahir

A novel time-reversal subwavelength transmission technique, based on pulse shaping circuits (PSCs), is proposed. Compared to previously reported approaches, this technique removes the need for complex or electrically large electromagnetic…

Optics · Physics 2015-10-28 Shuai Ding , Rui Zang , Lianfeng Zou , Bingzhong Wang , Christophe Caloz

Magnetization reversal by a femtosecond circularly polarized laser pulse has been recently demonstrated in rare-earth doped transition metals (RE-TM). The switching mechanism has been attributed to an inverse Faraday effect and thermal…

Materials Science · Physics 2007-09-10 A. Rebei , J. Hohlfeld

We describe a resonator based optical gyroscope whose sensitivity for measuring absolute rotation is enhanced via use of the anomalous dispersion characteristic of superluminal light propagation. The enhancement is given by the inverse of…

Quantum Physics · Physics 2007-05-23 M. S. Shahriar , G. S. Pati , R. Tripathi , V. Gopal , M. Messall , K. Salit

We simulate EM pulse propagation along the nonuniform earth surface using so called time-domain parabolic equation. To solve it by finite differences, we introduce a time-domain analog of the impedance boundary condition and a nonlocal BC…

Numerical Analysis · Mathematics 2007-05-23 Alexei V. Popov , Vladimir V. Kopeikin

The advent of isolated and intense sub-femtosecond X-ray pulses enables tracking of quantummechanical motion of electrons in molecules and solids. The combination of X-ray spectroscopy and diffraction imaging is a powerful approach to…

On-chip optical filters are fundamental components in optical signal processing. While rare-earth ion-doped crystals offer ultra-narrow optical filtering via spectral hole burning, their applications have primarily been limited to those…

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