LLE Review, Volume 98 73 Introduction Stimulated brillouin scattering (SBS) is the decay of an incident (pump) light wave into a frequency-downshifted (Stokes) light wave and an ion-acoustic (sound) wave.1 It is important in inertial confinement fusion (ICF) experiments because it scatters laser light away from the target, which reduces the laser energy that is available to drive the compressio...

In this talk, we shall present our recent progress on acoustic and electromagnetic cloaking of obstacles with transformation media. In wave scattering, an obstacle is an object that waves cannot penetrate inside. With artificially designed transformation media, we show that the obstacle can be virtually reshaped under acoustic or electromagnetic wave detection. These cloaking media are shown to...

An optimum design technique for balanced surface acoustic wave (SAW) filters is proposed. First of all, in order to evaluate the performance of balanced SAW filters by the computer simulation, a numerical model of balanced SAW filters is derived by using mixed-mode scattering parameters. Then the structural design of balanced SAW filters is formulated as a function optimization problem that aim...

The method of Acoustic Wavefield Imaging (AWI) offers many advantages over conventional ultrasonic techniques for nondestructive evaluation, and also provides a means of incorporating fixed ultrasonic sensors used for structural health monitoring into subsequent inspections. AWI utilizes these fixed sensors as wave sources and an externally scanned ultrasonic transducer (or laser interferometer...

Analysis of acoustic phonons modulated due to the surfaces of a free-standing semiconductor plate and their deformation-potential interaction with electrons are presented. The form factor for electron-modulated acoustic phonon interaction is formulated and analyzed in detail. The form factor at zero in-plane phonon wave vector satisfies sum rules regardless of electron wave function. The form f...

In the study, a retrieval approach is extended to determine the effective dynamic properties of a finite multilayered acoustic metamaterial based on the theoretical reflection and transmission analysis. The accuracy of the method is verified through a comparison of wave dispersion curve predictions from the homogeneous effective medium and the exact solution. A multiresonant design is then sugg...

A complete ultrasonic measurement model for surface and plate wave inspections is obtained, where all the electrical, electromechanical, and acoustic/elastic elements are explicitly described. Reciprocity principles are used to describe the acoustic/elastic elements specifically in terms of an integral of the incident and scattered wave fields over the surface of the flaw. As with the case of b...

LLE Review, Volume 74 113 Laser–plasma instabilities1 are important in the field of inertial confinement fusion2 because they scatter laser light away from the target, which reduces the laser energy available to drive the compression of the nuclear fuel, or generate energetic electrons that preheat the fuel, which makes the fuel harder to compress. In stimulated Raman scattering an incident, or...

A new method has been developed to predict acoustic scattering by weakly scattering objects with three-dimensional variability in sound speed and density. This variability can take the form of inhomogeneities within the body of the scatterer and/or geometries where the acoustic wave passes through part of the scattering body, into the surrounding medium, and back into the body. This method appl...

Conditions likely to lead to enhanced inelastic atomic scattering that creates shear horizontal (SH) and longitudinal acoustic (LA) monolayer phonons are identified, specifically examining the inelastic scattering of (4)He atoms by a monolayer solid of XePt(111) at incident energies of 2-25 meV. There is strong inelastic scattering for both dispersive phonon branches (SH and LA) of the monolaye...