Journal ArticleDOI
Wave phase conjugation of ultrasonic beams
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In this article, the current state of the acoustic wave phase conjugation (PC) problem is reviewed with emphasis on the parametric method using electromagnetic pumping in solids, and the giant-amplification supercritical parametric PC mode is considered in detail.Abstract:
The current state of the acoustic wave phase conjugation (PC) problem is reviewed. The generation of phase conjugate ultrasonic waves is discussed with emphasis on the parametric method using electromagnetic pumping in solids. The giant-amplification supercritical parametric PC mode is considered in detail. Ultrasonic PC with a gain in excess of 80 dB is demonstrated for a soft magnetic ceramics-based amplifier. The high quality of supercritical parametric PC sound is confirmed by acoustic-optical visualization. Acoustic PC effects, such as anomalous sound reflection at the PC mirror and the autofocusing and self-targeting of phase conjugate sound beams incident on a scatterer in a liquid, are shown. Recent experimental results demonstrating the potential of PC for applications are presented.read more
Citations
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Journal ArticleDOI
Time-reversed acoustics
Mathias Fink,Didier Cassereau,Arnaud Derode,Claire Prada,Philippe Roux,Mickael Tanter,Jean-Louis Thomas,F. Wu +7 more
TL;DR: In this paper, the authors show that time reversal invariance can be exploited in acoustics to create a variety of useful instruments as well as elegant experiments in pure physics, and they describe time reversal cavities and mirrors together with a comparison between time reversal and phase conjugation.
Journal ArticleDOI
Time-Reversal Wireless Paradigm for Green Internet of Things: An Overview
Yan Chen,Feng Han,Yu-Han Yang,Hang Ma,Yi Han,Chunxiao Jiang,Hung-Quoc Lai,David N. Claffey,Zoltan Safar,K. J. Ray Liu +9 more
TL;DR: An overview of the time-reversal (TR) wireless paradigm for green Internet of Things shows that the TR technique is a promising technique that focuses signal waves in both time and space domains and can enhance the privacy and security of customers in IoT.
Journal ArticleDOI
Effects of the nanocrystalline state in solids
TL;DR: In this article, the effect of the nanocrystalline state on the mechanical, thermal, and magnetic properties and microscopic structure of metals and solid-phase compounds are reviewed and the importance of interfaces in determining the structure and properties of compact nanomaterials is demonstrated.
Journal ArticleDOI
Metal modification by high-power pulsed particle beams
TL;DR: The state of the art in the modification of iron, steel, and titanium alloys and some metal multilayers by medium intensity (106-109 W cm−2) pulsed electron and ion beams is summarized in this article.
Journal ArticleDOI
Nonreciprocal sound propagation in space-time modulated media
TL;DR: In this article, sound propagation in a space-time modulated medium is theoretically studied and finite-difference time-domain simulations are carried out to verify the results, such as mode conversion, parametric amplification and phase conjugation.
References
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Journal ArticleDOI
Effects of the nanocrystalline state in solids
TL;DR: In this article, the effect of the nanocrystalline state on the mechanical, thermal, and magnetic properties and microscopic structure of metals and solid-phase compounds are reviewed and the importance of interfaces in determining the structure and properties of compact nanomaterials is demonstrated.
Journal ArticleDOI
Metal modification by high-power pulsed particle beams
TL;DR: The state of the art in the modification of iron, steel, and titanium alloys and some metal multilayers by medium intensity (106-109 W cm−2) pulsed electron and ion beams is summarized in this article.
Journal ArticleDOI
Negative energy waves in hydrodynamics
TL;DR: The utility of negative energy waves in hydrodynamics is discussed in this paper, where it is shown that energy defined as the first integral of the equations of motion linearized against the flow background can be negative whereas the inclusion of all the quadratic terms in the expression for the energy can give a positive value.
Journal ArticleDOI
Acoustic analogues of nonlinear-optics phenomena
TL;DR: In this paper, a review of nonlinear acoustic phenomena is presented, which are analogous to corresponding phenomena in optics: self-interaction effects in acoustic beams, parametric effects, stimulated scattering of sound, wavefront (phase) conjugation of sound waves, and also techniques of active acoustic spectroscopy.