Acoustics of finite-aperture vortex beams

TL;DR

This paper presents a rigorous method based on the Rayleigh-Sommerfeld integral to model and evaluate the acoustic scattering and mechanical effects of finite-aperture vortex beams, with applications in acoustic tweezers and microfluidics.

Contribution

It introduces a novel approach to accurately model finite-aperture vortex beams and derive partial-wave series expansions for their incident fields.

Findings

Enables precise computation of acoustic radiation force and torque.

Provides analytical expressions for high-order Bessel and Bessel-Gauss vortex beams.

Facilitates applications in particle manipulation and acoustic tweezers.

Abstract

A method based on the Rayleigh-Sommerfeld surface integral is provided, which makes it feasible to rigorously model, evaluate and compute the acoustic scattering and other mechanical effects of finite-aperture vortex beams such as the acoustic radiation force and torque on a viscoelastic sphere in various applications in acoustic tweezers and microfluidics, particle entrapment, manipulation and rotation. Partial-wave series expansions are derived for the incident field of acoustic spiraling (vortex) beams, comprising high-order Bessel and Bessel-Gauss beams.