Far-field and near-field directionality in acoustic scattering
arXiv:2003.13292 · doi:10.1088/1367-2630/ab9fbf
Abstract
Far-field directional scattering and near-field directional coupling from simple sources have recently received great attention in photonics: beyond circularly-polarized dipoles, whose directional coupling to evanescent waves was recently applied to acoustics, the near-field directionality of modes in optics includes phased combinations of electric and magnetic dipoles, such as the Janus dipole and the Huygens dipole, both of which have been experimentally implemented using high refractive index nanoparticles. In this work we extend this to acoustics: we propose the use of high acoustic index scatterers exhibiting phased combinations of acoustic monopoles and dipoles with far-field and near-field directionality. All solutions stem from the elegant acoustic angular spectrum of the acoustic source, in close analogy to electromagnetism. A Huygens acoustic source with zero backward scattering is proposed and numerically demonstrated, as well as a Janus source achieving face-selective and position-dependent evanescent coupling to nearby acoustic waveguides.
References in corpus (19)
- Spin-orbit interactions of light
- Directional visible light scattering by silicon nanoparticles
- Magnetic light
- Quantum spin Hall effect of light
- Strong magnetic response of submicron Silicon particles in the infrared
- Demonstration of zero optical backscattering from single nanoparticles
- Universal spin-momentum locking of evanescent waves
- Janus and Huygens' dipolar sources for near-field directionality
- Quantum Spin of Elastic Wave
- Observation of acoustic spin
- Acoustic Radiation Force and Torque on Small Particles as Measures of the Canonical Momentum and Spin Densities
- Transverse spin and surface waves in acoustic metamaterials
- Acoustic versus electromagnetic field theory: scalar, vector, spinor representations and the emergence of acoustic spin
- Experimental demonstration of linear and spinning Janus dipoles for polarisation and wavelength selective near-field coupling
- Interferometric evanescent wave excitation of nano-antenna for ultra-sensitive displacement and phase metrology
- Amplitude and phase control of guided modes excitation from a single dipole source:engineering far- and near-field directionality
- Evanescent Gravitational Waves
- Momentum-space geometric structure of helical evanescent waves and its implications on near-field directionality
- Measuring monopole and dipole polarizability of acoustic meta-atoms
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- Roadmap on structured waves
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- From Elastic Spin to Phonon Spin: Symmetry and Fundamental Relations
- Acoustic resonators: symmetry classification and multipolar content of the eigenmodes
- Acoustic Lateral Recoil Force and Stable Lift of Anisotropic Particles
- Radiation forces and torques in optics and acoustics
- The dependence of evanescent wave polarization on the losses of guided optical modes
- Generalized causality constraint based on duality symmetry reveals untapped potential of sound absorption
- Acoustic angular sorting of resonant subwavelength particles
- Optimal multipole center for subwavelength acoustic scatterers
- Lattice-induced sound trapping in biperiodic metasurfaces of acoustic resonators
- Unidirectional Transverse Scattering in Acoustic Dimers