Synthesizing acoustic drill beams by the superposition of detuned vortices

Abstract

We present acoustic drill beams. These singular beams show a dynamic intensity distribution matching the shape of a helix. The intensity distribution rotates along the axis of the beam with a controlled direction and angular frequency, therefore resembling the shape of a mechanical drill bit. Acoustic drills emerge elegantly as the spatio-temporal interference of two confocal and detuned vortex beams. The beam parameters are fully tuneable. The detuned frequency, detuning wave number, and detuned topological charge of the composing beams control the number of arms of the drill, the winding period, the rotation velocity, and its direction. We show that elongated drill beams are obtained using two high-order Bessel beams, enabling analytical solutions for optimal overlapping. In addition, drill beams can also be synthesized by focused ultrasound vortices. Analytic, numeric, and experimental results are shown in the ultrasound regime using a low-cost device based on two confocal 1-MHz piezoelectric transducers and 3D-printed acoustic holograms. This new wave structure opens novel avenues for wave-matter interaction such as contactless particle manipulation, matter processing, or biomedical applications.

@inproceedings{JimenezJASA2022Synthesizing,
 author = {Noé Jiménez and Enrique M. González-Mateo and Francisco Camarena and Kestutis Staliunas},
 booktitle = {182th Meeting of the Acoustical Society of America. Denver, Colorado, USA, 23-27 May},
 doi = {https://doi.org/10.1121/10.0010842},
 editor = {The Journal of the Acoustical Society of America},
 isbn = {ISSN: 0001-4966},
 month = {06},
 number = {4},
 organization = {Acoustical Society of America},
 pages = {A121},
 publisher = {AIP Publishing},
 series = {Invited},
 title = {Synthesizing acoustic drill beams by the superposition of detuned vortices},
 url = {https://asa.scitation.org/doi/abs/10.1121/10.0010842},
 volume = {151},
 year = {2022}
}