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Distortion free negative group velocity pulse propagation is demonstrated in a rare-earth-ion-doped-crystal (RE) through the creation of a carefully designed spectral absorption structure in the inhomogeneous profile of Eu:YSO and…

We propose a new type of optical switch based on a ferroelectric. It is based on the gap which exists for waves propagating from a dielectric to a ferroelectric material. This gap depends on the polarization of the ferroelectric. We show…

Optics · Physics 2015-06-11 J. -G. Caputo , A. I. Maimistov , E. V. Kazantseva

The time-reversal mirror (TRM) of acoustic waves is used as a focusing technique that is robust against disorder and chaos. The propagation of an ultrasonic pulse from the focal point is detected and recorded by a surrounding array of…

Mesoscale and Nanoscale Physics · Physics 2008-04-16 Hernan L. Calvo , Horacio M. Pastawski

Time-reversal symmetry is important to optics. In linear optics, a time-reversed process to laser emission enables total absorption of coherent light fields into an optical cavity of loss by time-reversing the original gain medium. In…

Optics · Physics 2013-01-15 Yuanlin Zheng , Huaijin Ren , Wenjie Wan , Xianfeng Chen

We introduce universal broadband composite pulse sequences for robust high-fidelity population inversion in two-state quantum systems, which compensate deviations in any experimental parameter (e.g. pulse amplitude, pulse duration, detuning…

Quantum Physics · Physics 2015-06-19 Genko T. Genov , Daniel Schraft , Thomas Halfmann , Nikolay V. Vitanov

A method is shown for preventing temporal broadening of ultrafast optical pulses in highly dispersive and fluctuating media for arbitrary signal-pulse profiles. Pulse pairs, consisting of a strong-field control-pulse and a weak-field…

Optics · Physics 2021-11-17 Haider Zia

This paper presents a novel approach for steering the state of a stochastic control-affine system to a desired target within a finite time horizon. Our method leverages the time-reversal of diffusion processes to construct the required…

Optimization and Control · Mathematics 2025-09-11 Yuhang Mei , Amirhossein Taghvaei , Ali Pakniyat

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

We present a simple electronic circuit which provides negative group delays for band-limited, base-band pulses. It is shown that large time advancement comparable to the pulse width can be achieved with appropriate cascading of…

Quantum Physics · Physics 2016-11-15 M. Kitano , T. Nakanishi , K. Sugiyama

Using time domain measurements, we assess the feasibility of time-reversal technique in ultra-wideband (UWB) communication. A typical indoor propagation channel is selected for the exploration. The channel response between receive and…

Networking and Internet Architecture · Computer Science 2008-10-09 Ali Khaleghi , Ghaïs El Zein , Ijaz Haider Naqvi

When a signal is emitted from a source, recorded by an array of transducers, time reversed and re-emitted into the medium, it will refocus approximately on the source location. We analyze the refocusing resolution in a high frequency,…

Disordered Systems and Neural Networks · Physics 2007-05-23 George Papanicolaou , Leonid Ryzhik , Knut Solna

We demonstrate experimentally a procedure to obtain the maximum efficiency for the storage and retrieval of light pulses in atomic media. The procedure uses time reversal to obtain optimal input signal pulse-shapes. Experimental results in…

The time reversal symmetry of the wave equation allows wave refocusing back at the source. However, this symmetry does not hold in lossy media. We present a new strategy to compensate wave amplitude losses due to attenuation. The strategy…

Classical Physics · Physics 2022-12-15 Crystal T. Wu , Nuno M. Nobre , Emmanuel Fort , Graham D. Riley , Fumie Costen

We study magnetization reversal using various r.f. magnetic pulses. We show numerically that switching is possible with simple sinusoidal pulses; however the optimum approach is to use a frequency-swept (chirped) r.f. magnetic pulse, the…

Materials Science · Physics 2015-06-25 K. Rivkin , J. B. Ketterson

Time reversal in a macroscopic system is contradicting daily experience. It is practically impossible to restore a shattered cup to its original state by just time reversing the microscopic dynamics that led to its breakage. Yet, with the…

We study inelastic resonant scattering of a Gaussian wave packet with the parameters close to a zero of the complex scattering coefficient. We demonstrate, both theoretically and experimentally, that such near-zero scattering can result in…

Broadband implementations of time-optimal geodesic pulse elements are introduced for the efficient creation of effective trilinear coupling terms for spin systems consisting of three weakly coupled spins 1/2. Based on these pulse elements,…

Quantum Physics · Physics 2009-11-10 Timo O. Reiss , Navin Khaneja , Steffen J. Glaser

We theoretically and experimentally establish a connection between linearly chirped pulse propagation properties and the complex generalization of Wigner-Smith time delay for both transmitted and reflected pulses in linear and dispersive…

We present a fast phase gate scheme that is experimentally achievable and has an operation time more than two orders of magnitude faster than current experimental schemes for low numbers of pulses. The gate time improves with the number of…

Quantum Physics · Physics 2013-04-10 C. D. B. Bentley , A. R. R. Carvalho , D. Kielpinski , J. J. Hope

We investigate the reversibility of laser filamentation, a self-sustained, non-linear propagation regime including dissipation and time-retarded effects. We show that even losses related to ionization marginally affect the possibility of…

Optics · Physics 2014-09-04 Nicolas Berti , Wahb Ettoumi , Jérôme Kasparian , Jean-Pierre Wolf