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Related papers: Pushing the limits of negative group velocity

200 papers

We carry out experiments of low velocity normal impacts into granular materials that fill an approximately cylindrical 42 litre tub. Motions in the granular medium are tracked with an array of 7 embedded accelerometers. Longitudinal pulses…

By spectrally hole burning an inhomogeneously broadened ensemble of ions while applying a controlled perturbation, one can obtain spectral holes that are functionalized for maximum sensitivity to different perturbations. We propose to use…

Quantum Physics · Physics 2017-01-03 Klaus Mølmer , Yann Le Coq , Signe Seidelin

We demonstrate a high throughput, large compensation range, single-prism femtosecond pulse compressor, using a single prism and two roof mirrors. The compressor has zero angular dispersion, zero spatial dispersion, zero pulse-front tilt,…

Optics · Physics 2013-06-24 Lingjie Kong , Meng Cui

The diffraction of electromagnetic plane waves by a rectangular grating formed by discrete steps in the interface of a homogeneous, isotropic, linear, negative phase--velocity (negative index) material with free space is studied using the…

Optics · Physics 2009-11-11 Ricardo A. Depine , Akhlesh Lakhtakia , David R. Smith

Ultrashort laser pulses enable attosecond-scale measurements and drive breakthroughs across science and technology, but their routine use hinges on reliable pulse characterization. Frequency-Resolved Optical Gating (FROG) is a leading…

Optics · Physics 2026-04-29 Abhimanyu Borthakur , Jack Eden Hirschman , Sergio Carbajo

The serrodyne principle enables shifting the frequency of an electromagnetic signal by applying a linear phase ramp in the time domain [1]. This phenomenon has been exploited to frequency-shift signals in the radiofrequency (RF), microwave…

Wave propagation in spatially periodic media, such as photonic crystals, can be qualitatively different from any uniform substance. The differences are particularly pronounced when the electromagnetic wavelength is comparable to the…

Optics · Physics 2007-05-23 A. Figotin , I. Vitebskiy

We propose a solid-state based superradiance laser which is almost insensitive to the cavity mirror vibration. Therefore, it can compete with the best frequency-stable local oscillators. The long coherence time and the large optical density…

Quantum Physics · Physics 2020-04-01 Mahmood Sabooni

We present robust radio frequency (rf) pulses that tolerate a factor of six inhomogeneity in the B1 field, significantly enhancing the potential of toroid cavity resonators for NMR spectroscopic applications. Both point-to-point (PP) and…

Chemical Physics · Physics 2015-05-20 Thomas E. Skinner , Michael Braun , Klaus Woelk , Naum I. Gershenzon , Steffen J. Glaser

We report the experimental demonstration of the superluminal propagation of multi-spatial-mode images via four-wave mixing in hot atomic vapor, in which all spatial sub-regions propagate with negative group velocities. We investigate the…

Quantum Physics · Physics 2012-06-06 Ryan T. Glasser , Ulrich Vogl , Paul D. Lett

To accelerate ultra-relativistic charged particles, such as electrons, using an electromagnetic pulse along a hollow-core waveguide, the pulse needs to have a longitudinal electric field component and a phase velocity of $c$, the speed of…

Accelerator Physics · Physics 2024-12-30 Aku Antikainen , Siddharth Ramachandran

We present a composite pulse controlled phase gate which together with a bus architecture improves the feasibility of a recent quantum computing proposal based on rare-earth-ion doped crystals. Our proposed gate operation is tolerant to…

Quantum Physics · Physics 2007-05-23 Janus Wesenberg , Klaus Moelmer

We investigated the propagation of a squeezed optical field, generated via the polarization self-rotation (PSR) effect, with a sinusoidally-modulated degree of squeezing through an atomic medium with anomalous dispersion. We observed the…

Optics · Physics 2014-02-17 Gleb Romanov , Travis Horrom , Irina Novikova , Eugeniy E. Mikhailov

We present a novel laser based ion acceleration scheme, where a petawatt circularly polarized laser pulse is shot on an ultra-thin (nano-scale) double-layer target. Our scheme allows the production of high-quality light ion beams with both…

Plasma Physics · Physics 2013-09-06 M. Grech , S. Skupin , R. Nuter , L. Gremillet , E. Lefebvre

We demonstrate a tilted pulse-front transient grating technique that allows to optimally utilize time-resolution as well as transient grating line density while probing under grazing incidence as typically done in extreme ultraviolet (EUV)…

Instrumentation and Detectors · Physics 2018-08-29 A. Battistoni , H. A. Dürr , M. Gühr , T. J. A. Wolf

Metasurfaces impart phase discontinuities on impinging electromagnetic waves that are typically limited to 0-2$\pi$. Here, we show that they can break free from this limitation and supply arbitrarily-large phase modulation over ultra-wide…

Applied Physics · Physics 2019-02-05 Odysseas Tsilipakos , Thomas Koschny , Costas M. Soukoulis

We investigate the role of non-uniform spatial density profiles of trapped atomic Bose-Einstein condensates in the propagation of Raman-matched laser pulses under conditions for electromagnetically induced transparency (EIT). We find that…

Quantum Physics · Physics 2009-11-07 Özgür E. Müstecaplıoğlu , L. You

Based on the similarity of paraxial diffraction and dispersion mathematical descriptions, the temporal imaging of optical pulses combines linear dispersive filters and quadratic phase modulations operating as time lenses. We consider…

In this paper we develop a method capable of modeling the space-time focusing of nondiffracting pulses. The new pulses can possess arbitrary peak velocities and, in addition to being resistant to diffraction, can have their peak intensities…

Optics · Physics 2016-10-19 Michel Zamboni-Rached , Ioannis M. Besieris

Time reversal (TR) is a promising technique that exploits multipaths for achieving energy focusing in high-frequency wideband communications. In this letter, we focus on a TR scheme facilitated by a reconfigurable intelligent surface (RIS)…

Signal Processing · Electrical Eng. & Systems 2024-08-27 Andreas Nicolaides , Constantinos Psomas , Ioannis Krikidis